Invasive “hot spot” study confirms vulnerable places, causes of introductions

removing Miconia from Hawaiian forest; courtesy of the Nature Conservancy of Hawai`i

A recent article by Wayne Dawson and 24 coauthors (see reference at the end of this blog) provides the first-ever global analysis of established alien species. They studied the diversity of established alien species belonging go eight taxonomic groups – amphibians, ants, birds, freshwater fish, mammals, reptiles, spiders and vascular plants – across 609 regions (186 islands or archipelagos, and 423 mainland regions).

The analysis found that the highest numbers of established alien species in these taxonomic groups were in the Hawaiian Islands, New Zealand’s North Island and the Lesser Sunda Islands of Indonesia. The Hawaiian Islands have high numbers of invasive species in all of the eight groups studied. In New Zealand, the highest numbers were invasive plants and introduced mammals that prey on the native birds.

Florida is the top hotspot among mainland regions. Florida is followed by the California coast and northern Australia.

Burmese python in the Florida Everglades; photo by U.S. Fish & Wildlife Service

Patterns

 Invasive species hotspots were found mainly on islands and in coastal regions of mainland areas. The lead author, Dr. Wayne Dawson, a researcher at Durham University’s Department of Biosciences, suggested that the greater invasive species richness in coastal regions probably results from higher rates of species introductions to port areas compared to interior regions.

Island regions have, on average, higher cross-taxon invasive species richness. This cross-taxon richness on islands tends to be higher for those islands further from continental landmasses. The authors suggest that such oceanic islands might be more likely to import large quantities of goods from foreign sources than islands close to continents, thus experiencing higher propagule pressure.

 

Associations

Regions with greater wealth (measured as per capita GNP), human population density, and area have higher established alien richness. These effects were strongest on islands. The authors suggest that wealth and human population density might correlate with higher numbers of species being brought to the region through trade and transport.

On mainlands, cooler regions have higher richness. I think this might reflect history – centuries of colonial powers importing plants and animals. However, colonial powers also introduced species to tropical regions.  In contrast, on islands warmer and wetter regions have higher richness of invasive species.

 

Drivers

The authors conclude that cumulative numbers of invasive species at a particular location are driven to a greater extent by differences in area and propagule pressure than by climate. The model that best explains cross-taxon invasive species richness combines per capita GDP, population density and sampling effort. Other important factors are area of the region, mean annual precipitation, and whether a region is on a mainland or island(s).

The study results show that, per unit increase in area, per capita GDP, and population density, invasive species richness increases at a faster rate on islands than on mainlands. This might be confirmation of the longstanding belief that islands are more readily invaded than mainlands, although the authors caution that a rigorous test of this explanation would require data on failed introductions.

The authors call for additional research to understand whether these effects arise because more species are introduced to hotspot regions, or because human disturbance in these regions makes it easier for the newcomers to find vacant spaces and opportunities to thrive.

 

I think it would be helpful to compare the findings on invasive species richness in specific regions to data on historic patterns of trade and colonization to strengthen our understanding of the importance of propagule pressure in determining invasion patterns.

 

Increasing Confirmation of Significance and Breadth of Invasive Species Threat

The Dawson et al. study is the latest in a series of analyses of global or regional patterns in invasive species. I have blogged previously about several of these:

  • Bradshaw et al. 2016 concluded that invasive insects alone cause at least $77 billion in damage every year, a figure they described as a “gross underestimate”.
  • A study by Hanno Seebens and 44 coauthors showed that the rate of new introductions of alien species has risen rapidly since about 1800 – and shows no sign of slowing down. Adoption of national and international biosecurity measures have been only partially effective, failing to slow deliberate introductions of vascular plant species, birds, and reptiles, and accidentally introduced invertebrates and pathogens. Like Dawson et al, Seebens et al. found a strong correlation between the spread of bioinvaders introduced primarily accidentally as stowaways on transport vectors or contaminants of commodities (e.g., algae, insects, crustaceans, molluscs and other invertebrates) and the market value of goods imported into the region of interest.
  • Liebhold et al. 2016(see reference below) studied insect assemblages in 20 regions around the world. They found that an insect taxon’s ability to take advantage of particular invasion pathways better explained the insect’s invasion history than the insects’ life-history traits. (The latter affect the insect’s ability to establish in a new ecosystem.)
  • Maartje J. Klapwijk and several colleagues note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900.
  • Jung et al. (2015) studied the presence of Phytophthora pathogens in nurseries in Europe. They found 59 putatively alien Phytophthora taxa in the nurseries. Two-thirds were unknown to science before 1990. None had been intercepted at European ports of entry when they were introduced. Nor have strict quarantine regulations halted spread of the quarantine organism ramorum.
  • A report by The World Conservation Union (IUCN) on World Heritage sites globally found that invasive species were second to poaching as a threat to the sites’ natural values. Of 229 natural World Heritage sites examined, 104 were affected by invasive species. Island sites – especially in the tropics – were most heavily impacted.
  • Another report by IUCN found that invasive species were the second most common cause of species extinctions – especially for vertebrates.

Conclusions

These studies demonstrate that

  • Invasive species have become a significant threat to biological diversity and ecosystem services around the world – one that continues to grow.
  • The recent spate of studies originating in Europe probably reflects recent recognition of the continent’s vulnerability – as seen, inter alia, in the proliferation of tree-killing Phytophthoras.
  • Human movement of species – propagule pressure – whether deliberately or due to inadequate efforts to manage trade-related pathways – explain the bulk of “successful” introductions.
  • Economic activity drives introductions, so areas at highest immediate risk are urban areas and other centers receiving high volumes of imports and visitors. Among troubling trends in the future is rapid global urbanization – along with rising economic interdependency.
  • Efforts to curb these movements – at the national, regional, and international levels – have failed so far to counter the threat posed by invasive species of nearly all taxonomic groups.

In my view, the requirements that phytosanitary measures “balance” pest prevention against trade facilitation results in half measures being applied – and half measures achieve halfway results. For example, the U.S. does not require that packaging be made from materials that cannot transport tree-killing pests. The USDA has moved far too slowly to limit imports of plant taxa that pose a risk of either being invasive themselves or of transporting pests known to be damaging.

 

Conservationists should focus on building political pressure to strengthen regulations and other programs intended to curtail this movement. No other approach will succeed.

 

Sources

Bradshaw, C.J.A. et al. Massive yet grossly underestimated global costs of invasive insects. Nat. Commun. 7, 12986 doi: 10.1038/ncomms12986 (2016). (Open access)

Dawson, W., D. Moser, M. van Kleunen, H. Kreft, J. Perg, P. Pyšek, P. Weigelt, M. Winter, B. Lenzner, T.M. Blackburn, E.E. Dyer, P. Cassey, S.L. Scrivens, E.P. Economo, B. Guénard, C. Capinha, H. Seebens, P. García-Díaz, W. Nentwig, E. García-Berthou, C. Casal, N.E. Mandrak, P. Fuller, C. Meyer and F. Ess. 2017. Global hotspots and correlates of IAS richness across taxon groups. Nature Ecology and Evolution Vol. 1, Article 0186. DOI: 10.1038/s41559-017-0186 | www.nature.com/natecolevol

 

Jung,T., L. Orlikowski, B. Henricot, P. Abad-Campos, A.G. Aday, O. Aguin Casa, J. Bakonyi, S.O. Cacciola, T. Cech, D. Chavarriaga, T. Corcobado, A. Cravador, T. Decourcelle, G. Denton, S. Diamandis, H.T. Doggmus-Lehtijarvi, A. Franceschini, B. Ginetti, M. Glavendekic, J. Hantula, G. Hartmann, M. Herrero, D. Ivic, M. Horta Jung, A. Lilja, N. Keca, V. Kramarets, A. Lyubenova, H. Machado, G. Magnano di San Lio, P.J. Mansilla Vazquez, B. Marais, I. Matsiakh, I. Milenkovic, S. Moricca, Z.A. Nagy, J. Nechwatal, C. Olsson, T. Oszako, A. Pane, E.J. Paplomatas, C. Pintos Varela, S. Prospero, C. Rial Martinez, D. Rigling, C. Robin, A. Rytkonen, M.E. Sanchez, B. Scanu, A. Schlenzig, J. Schumacher, S. Slavov, A. Solla, E. Sousa, J. Stenlid, V. Talgø, Z. Tomic, P. Tsopelas, A. Vannini, A.M. Vettraino, M. Wenneker, S. Woodward and A. Perez-Sierra. 2015. Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora disease. Forest Pathology.

 

Klapwijk, M.J., A.J.M. Hopkins, L. Eriksson, M. Pettersson, M. Schroeder, A. Lindelo¨w, J. Ro¨nnberg, E.C.H. Keskitalo, M. Kenis. 2016. Reducing the risk of invasive forest pests and pathogens: Combining legislation, targeted management and public awareness. Ambio 2016, 45(Suppl. 2):S223–S234  DOI 10.1007/s13280-015-0748-3  [http://www.nature.com/articles/ncomms14435 ]

 

Liebhold, A.M., T. Yamanaka, A. Roques, S. Augustin, S.L. Chown, E.G. Brockerhoff, P. Pysek. 2016. Global compositional variation among native and nonindigenous regional insect assemblages emphasizes the importance of pathways. Biological Invasions (2016) 18:893–905

 

Seebens, H. et al., 2017. No saturation in the accumulation of alien species worldwide. Nature Communications. January 2017. [http://www.nature.com/articles/ncomms14435 ]

 

 

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

 

Posted by Faith Campbell

 

 

Bill aimed at controlling invasive species on the ground advances

whitebark pine in Crater Lake National Park killed by white pine blister rust; photo by F.T. Campbell

In the first days of April, the Senate Environment and Public Works Committee  adopted the Wildlife Innovation and Longevity Driver Act (S. 826) (the WILD Act).

Title II of this legislation would amend the Fish and Wildlife Coordination Act by inserting language very similar to the Federal Land Invasive Species Control, Prevention, and Management Act (S. 509).  I blogged last year about that  bill and a hearing about it here.

Our concerns at the time focused on:

  • The provision allowing invasive control projects to proceed without first being evaluated by an environmental impact statement or environmental assessment. Lack of careful analysis could expose the environment to additional damage. For example, use of herbicides or grazing to control invasive plants can lead to suppression of native forbs. Suppressing invasion by one set of plants – whatever the strategy used – often facilitates a secondary invasion.
  • The mandatory funding allocations – which severely limit funds available to support research, outreach, and strategic planning and coordination – could undercut activities crucial to development and implementation of effective strategies and management tools.
  • The mandatory goal of reducing invasive species populations by 5% per year is unrealistic.
  • New requirements on reporting and coordination might divert already-thin resources and delay needed action.
  • Priority-setting. Managing invasive species on national lands should reflect national goals and perspectives, not be set by states’ governors.

Caroline Murphy of The Wildlife Society and I have reviewed Title II of the new WILD Act and find that it differs from last year’s invasive species control bill in several important ways:

  • The bill now applies to a wider range of agencies. The Secretary of the Army (who supervises the Corps of Engineers) is included explicitly; he joins the secretaries of Interior and Agriculture (as supervisor of the Forest Service). In addition, the bill also applies to the head of “any federal agency” having duties related to planning or treatment of invasive species “for the purpose of protecting water and wildlife on land and in water.”
  • Most important, projects are no longer granted a “Categorical Exclusion” from preparing environmental impact analyses. Instead, under an “Expedited Action” provision, the Secretaries are instructed to use all existing legal tools and flexibilities to expedite projects and activities.
  • The bill still requires that 75% of invasive species funds be allocated to “on-the-ground control and management of invasive species.” But such activity now may include “the use of appropriate methods to remove invasive species from a vehicle or vessel capable of conveyance.” I wish the language also included efforts to prevent invasive species from being present in or on the vehicle or vessel.
  • The bill has dropped the requirement that invasive species’ populations be reduced by 5% annually. The bill now requires the Secretaries to develop a strategic plan “to achieve, to the maximum extent practicable, a substantive annual net reduction of invasive species populations or infested acreage on land or water” that the Secretary manages. It is still not clear whether that reduction should apply to some or all of the invasive species there.

I am still concerned that

  • Projects are to use least-cost methods. This requirement is likely to favor reliance on chemical controls, which could have significant non-target impacts and might not provide lasting control. This incentive might be counter-balanced by the requirement that the methods be effective, based on sound scientific data. However, the bill’s focus on measuring annual results rather than long-term efficacy will add to pressures to rely on short-term approaches that could undermine long-term effectiveness.
  • Leadership of the projects – especially setting priorities – will be in hands of state governments, not the federal agencies which have the responsibility under federal law to manage the lands and waters that are to be protected. A partial counter-balance is the requirement that the appropriate federal agency Secretary determine which lands or waters need immediate action to address the invasive species risk.  Furthermore, the expedited actions are to be carried out in accordance with agency procedures, including any applicable land or resource management plan

I welcome the requirement that the Secretaries, in developing their strategic plans, must take into consideration the ecological as well as the economic costs of acting or not acting.

As before, the projects are to be carried out through collaboration with wide range of partners, including private individuals and entities – apparently including non-governmental organizations such as state or local invasive plant coalitions.

The rest of the WILD Act would reauthorize the Partners for Fish and Wildlife Program, some Multinational Species Conservation Fund Programs, and create several conservation-related competitive grant programs to be managed by the National Fish and Wildlife Foundation, one of which is for the management of invasive species.

Now that these provisions are incorporated into a wider bill, and Senator Barasso is chairman of the full committee, adoption of some version of this legislation now seems more likely than I thought last year.  Apparently there is still no action in House on the parallel bill.

While I am heartened by some of the changes in the bill since last year, I continue to think that America’s public lands would be better protected by a more comprehensive approach that includes prevention, mapping, early detection, research, prioritization, coordination and outreach aimed at engaging key stakeholders.  Such an approach was outlined in a document developed a couple of years ago by the National Environmental Coalition on Invasive Species (NECIS) – available here.

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

Injurious species ruling could lead to more invasions​

 

CISP and I are mentioned in this Newsweek article of April 12 ​about a court ruling that undercut ​ ​the past 28 years of the ​U.S. ​Fish and Wildlife Service’s ​(FWS)​ program of regulating “injurious species” under the Lacey Act at the level of interstate transportation within the 49 continental States.

​​

Dr. Skip Snow, National Park Service Herpetologist, Everglades National Park, examines python captured in the Park; NPS photo

LANDMARK CASE PAVES WAY FOR ANIMALS LIKE PYTHONS TO BE TRADED IN U.S.

​http://www.newsweek.com/landmark-case-paves-way-animals-pythons-be-legally-traded-us-583137 ​
What happened? In 201​3​, in ​DC ​District Court, the U.S. Association of Reptile Keepers (USARK) brought a suit that, among other arguments, claimed ​the Government (the ​USFWS), lacked statutory authority under the Lacey Act to regulate interstate commerce in large constrictor snakes among the 49 continental States​. The DC District Court agreed and that issue was ​prompt​ly appealed to the DC Circuit Court of Appeals​. Its ​April 7th ​opinion frames the issue like this (pp. 2-3):​

   

When a species is designated as injurious, the Act prohibits any importation of the species into the United States or its ​p​ossessions or territories. 18 U.S.C. § 42(a)(1). The Act additionally bars “any shipment” of the species“ ​​between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States.” Id.

​    ​

This case concerns the proper interpretation of the latter provision, which we will refer to as the shipment clause. All agree that the clause bars shipments of injurious species between each of the listed jurisdictions—for instance, shipments of animals between “Hawaii” and “the continental United States,” or between “the Commonwealth of Puerto Rico” and a “possession of the United States.” But what about ​shipments between the states making up “the continental United States”—for instance, shipments between Virginia and Maryland? Does the clause prohibit those shipments as well?​

 

The Court ​of Appeals ​answered the last question with a convincing “no”.​ 

 

It is important to note the effect is only on ​interstate commerce (“​IC ​”)​ among the 49 States and it does not change the FWS’ authority to regulate commerce between those named locations, that is, ​Hawaii, DC, PR, the possessions and the 49 States considered as one block​.  Also, the ruling does not ​at all ​affect the FWS’ authority to regulate imports of injurious species from other nations.

 

Was it unexpected? No. The USARK attorneys did outstanding legal work in revealing the early Legislative history ​ of the 1960 Lacey amendments at issue​ and the fact that,​ from 1960 through 1989, the FWS itself interpreted the statute not to allow it to regulate IC. The FWS only began regulating IC in its ​Lacey ​injurious species listings ​in​ about 1989, but it has continued to do that in every listing since 1989, ​under the last 5 Presidential administrations. The long delay in the Court challenge was largely due to lack of enough economic incentive for a regulated industry to bring a lawsuit to challenge ​the FWS changed approach​. It was not until USARK was motivated to raise a vast amount of contributions from its members to pays it large legal fees that a challenge was organized.

 

How broad is the ruling? Sweeping. It is n​either​ limited to the parties in th​e​ case ​n​or ​to the ​snakes involved. The opinion makes clear that the correct legal interpretation by the FWS from now on must be not to regulate IC among the continental 49 States, with this statement on p. 22:

 

   we …. hold as a matter of law that the government lacks authority under the shipment clause to prohibit shipments of injurious species between the continental States.     

 

Will there be more proceedings in the District Court? Likely yes, as USARK had brought other legal arguments claiming that the entire listings of their snakes (including regulation of foreign imports too) was illegal. Now that the pressing issue of the IC restriction ​for injurious species under the Lacey Act ​has been resolved, USARK can still make those arguments back in the District Court. My judgment ​as an attorney ​is those were all weak arguments and ultimately the listing of the snakes and trade restrictions will be upheld as legal by the Courts as far as ​regulating ​foreign imports and the commerce among the listed locations.

 

Is the ruling disallowing IC restrictions likely to have more appeals? No. It is theoretically possible that the Government could seek review from the Supreme Court, but doubtful that the Government will do that or that the Supreme Court would take the case.  Both the District Court Judge and the DC Circuit Court of Appeals (3 Judges) wrote very well-reasoned opinions, and there is no dissenting opinion or conflicting decision from any other Court. Given those circumstances, it is not the sort of case the Supreme Court would take, so the DC Circuit’s opinion should be considered the final word unless Congress changes the law.

 

When does it take effect? Immediately​, unless it is somehow blocked​. While the appeal was from a preliminary injunction, the ruling need not go back to the District Court now as far as the IC issue – that is decided as a matter of law. As the opinion pointed out ​(​pp. 7-8​)​​:​

 

      We reach a definitive judgment on the shipment clause’s meaning in order to “save the parties the expense of future l​itigation​”.​

     ​

What is the effect on existing Lacey Act injurious species listings? All existing injurious species listing regulations that claim to regulate IC must from now on be interpreted not to regulate IC. The FWS may re-issue some new listing regulations to make its lack of authority more clear, but even if the FWS delays in doing that the language in those regulations on regulating IC is now a nullity, that is, ​that language​  should be treated as if it does not exist.

 

It should be noted that ​ for​ the ​now​ 2​8​ different injurious species listing ​ decisions​ (some of which take in large numbers of species ​ totaling ~ 300 or up to ~700 species if the disease regulations are included​) th​e​ impact of this listing will vary greatly.  ​In reality​ only ​5 or 6​listings are significantly harmed ​now ​by the ruling. Most of the Lacey species listed are not in the US yet, ​e.g., Racoon dog, ​so the elimination of the IC restriction will have no effect currently and the continuing regulation of ​importation is all that is needed ​, unless the species does appear somewhere within the ​49 continental States​.

One ​listed species​, zebra mussel, ​is so widespread in the US ​already ​and/or ​its​ movement is generally unintentional s​o​ that the IC restriction has ​generally​ been unenforceable as a practical matter ​ (with some ​important ​exceptions to that)​.

 

One listing — the “all-salmonids pathogens” listing — was by its terms limited to regulating foreign imports and not IC, so it was not affected ​at all ​by the ruling.

 

But, for ​the ​listings ​​of​ the large constrictor snakes, the ​4 ​Asian carps​,​ the Northern snakehead​ and some others​, the Court ruling eliminating IC regulation will greatly weaken Federal control over the ​many ​species ​ within those listings​. ​Several​ of them are already fairly widespread ​in the country ​with captive and/or wild breeding populations to draw stock from. So ​just ​regulating their foreign importation is almost meaningless –  it is IC that is their most important risk. So​,​ we are more likely to see more invasions ​by those species i​n more States due to more ​unregulated ​IC unless that legal gap is filled.

 

Bsal regulation effect:​ The Bsal-prevention salamander ​foreign import ​regulation has been successful in keeping the Bsal pathogen out of the US (it appears​,​ based on monitoring so far), but the IC restriction had provided​ important ​insurance​ in the event that the pathogen is ​in fact ​here but just has yet to be detected. Or if the pathogen were to arrive, the IC restrictions would ​have ​facilitate​d​ a stronger preventative response, ​blocking or ​slowing spread from one State to another. ​Now, ​if the pathogen arrives with ​no IC restrictions in place, interstate trade in ​infected ​salamanders could rapidly spread a potentially devastating, nationwide, ​Bsal outbreak.

 

What is the effect on existing permits for interstate movement of listed species? To the extent the permits relate to foreign imports or movements between Hawaii, DC, ​PR, ​the ​possessions/​

territories or the continental States  considered as a whole​, the permit system is still in effect. As far as permits ​for movements ​within the continental 49 States, it should be expected that the FWS will modify their terms. Until the FWS does that or provides clarification​,​ the permit holders should ​follow​ the terms of their permits.

 

What might Congress do in response? Congress could pass a law filling the gap and returning ​the ​FWS IC regulation ​program ​to the status quo that has exist​ed​ since 1989. Such a law could be quite narrow, targeting only the IC gap, or it could be broader, including an IC gap fix within a broader new law. Or Congress could take no action, leaving the effect of the Court ruling in place.

 

What might State fish and wildlife agencies do in response? Unless it appears that Congress will fill the IC gap quickly, then concerned States may wish to promptly ​adopt ​their own new laws ​/regulations​ restricting commerce into their States of the species involved. This seems ​the ​highest priority for the States most at risk from the species whose IC has been most liberalized by the ruling, that is, the large constrictor snakes, the ​4​ Asian carps​,​ the Northern snakehead and ​the ​salamanders that the FWS listed as potentially carrying Bsal. (Some States already may have such restrictions on the books.)

 

​ Note that Hawaii is well-protected as a specially-designated State and need take no action, as is also true for DC, PR and the territories.​

 

It is too soon to know what the policy responses may be, but the FWS, State agencies and stakeholders likely are evaluating options now. ​

 

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

​Posted by Peter Jenkins

 

Alien species introductions — going up!

trade transports many invasive species

Containers at Long Beach, California; courtesy of the Port Authority

In an article published recently in Nature Communications , Hanno Seebens and 44 coauthors show that the rate of new introductions of alien species has risen rapidly since about 1800 – and shows no sign of slowing down. See a summary of the article with revealing graphs here .

Through analysis of a database covering 45,813 first records of 16,926 alien species established in 282 distinct geographic regions, the authors determined that the number of new species reports reached a maximum of 585 in 1996 (or an average of more than 1.5 sightings per day).

Of course, whether a species’ introduction is detected depends on a variety of factors. One of the most important is the species’ impact – or lack thereof! – on economically important resources – this determines whether the species gets noticed. Furthermore, detection usually happens some time after a species’ actual introduction. And, regardless of factors motivating human attention, some types of species are more easily detected than others. All these factors skew the findings. Because many introductions are not detected, Seebens et al. note, their data underestimate actual introductions.

The authors found that the adoption of national and international biosecurity measures during the 20th century have slowed introductions – but they are not yet sufficiently effective. Most notably, numbers of reported new introductions of fish and mammals have decreased since the early 1950s. Of course, introductions of these taxa are usually the result of deliberate decisions, usually by authorities. It is encouraging that authorities appear to be getting the message that adding new species to an ecosystem is a risky enterprise.

 

Japanese honeysuckle; courtesy of Bugwood.org

However, not all deliberate introductions have been curbed. Seebens et al. were surprised to see that vascular plant species introductions remained at such a high rate throughout the 20th century. Introductions of birds and reptiles also continue to rise, largely as pets in countries with strengthening economies.

For those plants and animals that are introduced primarily accidentally as stowaways on transport vectors or contaminants of commodities (e.g., algae, insects, crustaceans, molluscs and other invertebrates), Seebens et al. found a strong correlation between their spread and the market value of goods imported into the region of interest.

Having noted that almost all biosecurity efforts are not yet slowing introductions adequately, Seebens et al. point to New Zealand as the exception. That country adopted the Biosecurity Act in 1993 and the Hazardous Substances and New Organisms Act in 1996.

Although 20 years is a short period to gauge a policy’s efficacy – especially given time lags in detecting introductions – Seebens et al. say the stringent new policy appears to be succeeding. They found a significant decline in the number of new alien plants detected in New Zealand since the 1990s. New Zealand’s laws rely on a “white list” of permitted species rather than the more usual “black list” of prohibited species. New Zealand requires a risk assessment before a decision is made to allow any new species to be brought into the country.

Of course, such an approach does not apply easily to the taxa most often introduced as unintended hitchhikers on, or as contaminants of, imported goods, packaging, or transport vehicles – such as tree-killing insects and diseases. The paper notes that existing biosecurity regimes have not slowed down the accumulation of alien species introductions overall, but especially those arriving mainly accidentally, such as invertebrates and pathogens.

As a consequence, Seebens et al. expect that the numbers of new alien species will continue to increase.

I have previously blogged about other studies that show continuing introductions of forest pests and other specific taxonomic groups.  See blogs about (1) 2014 IUCN report on invasive species threats to World Heritage sites; (2) IUCN analysis of red-book-listed species – causes of endangerment; (3) rate of new plant pests being detected in US; (4) Jung et al. on Phytophthoras in Europe; (5) Zamir’s critique of international the phytosanitary system; (6) Klapwjik et al. on European efforts to strengthen regulations governing movement of living plants; (7) ISPM#15 11th anniversary.

Other recent studies have also examined the bioinvasion situation for the whole Earth or major regions. Liebhold et al. 2016 studied insect assemblages in 20 regions around the world. They found that which insect orders are present in a particular region differs completely depending on whether one is looking at native or at nonindigenous assemblages. The authors believe that difference is largely caused by the varying probability that an insect taxon can take advantage of one or more high-volume invasion pathways – such as trade in agricultural products, movement of plants by international travelers, shipments of stored grain, trade in living plants, hitchhiking (e.g. on the outside of shipping containers) and wood packaging. Pathway association appeared to be more important than insects’ life-history traits, which affect their ability to establish in a new ecosystem.

Maartje J. Klapwijk and several colleagues note that growing trade in living plants and wood products has brought a rise in non-native tree pests becoming established in Europe. The number of alien invertebrate species has increased two-fold since 1950; the number of fungal species has increased four-fold since 1900.

Jung et al. (2015) studied the presence of Phytophthora pathogens in nurseries in Europe. They found

  • Two-thirds of the Phytophthora taxa detected in European nurseries by the present study were unknown to science before 1990.
  • None of the 59 putatively exotic Phytophthora taxa detected in the present study had been intercepted at European ports of entry.
  • Spread of the quarantine organism ramorum has not been halted despite the presence of strict quarantine regulations.

I will post a blog examining introduction rates for tree-killing insects and pathogens specifically in the near future. In the meantime, see the published studies listed below as well as my earlier blogs and fact sheets posted here .

Aukema, J.E., B. Leung, K. Kovacs, C. Chivers, K. O. Britton, J. Englin, S.J. Frankel, R. G. Haight, T. P. Holmes, A. Liebhold, D.G. McCullough, B. Von Holle.. 2011. Economic Impacts of Non-Native Forest Insects in the Continental United States PLoS One September 2011 (Volume 6 Issue 9)

Aukema, J.E., D.G. McCullough, B. Von Holle, A.M. Liebhold, K. Britton, & S.J. Frankel. 2010. Historical Accumulation of Nonindigenous Forest Pests in the Continental United States. Bioscience. December 2010 / Vol. 60 No. 11

Haack RA, Britton KO, Brockerhoff EG, Cavey JF, Garrett LJ, et al. (2014) Effectiveness of the International Phytosanitary Standard ISPM No. 15 on Reducing Wood Borer Infestation Rates in Wood Packaging Material Entering the United States. PLoS ONE 9(5): e96611. doi:10.1371/journal.pone.0096611

Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org

Liebhold, A.M., T. Yamanaka, A. Roques, S. Augustin, S.L. Chown, E.G. Brockerhoff, P. Pysek. 2016.  Global compositional variation among native and nonindigenous regional insect assemblages emphasizes the importance of pathways. Biological Invasions (2016) 18:893–905

Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig , F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, S.L. LaDeau, and T. Weldy. 2016. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications, 0(0), 2016, pp. 1–19. DOI 10.1890/15-1176.1

 

 

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

 

New Secretary of Interior Pledges to Support Invasive Species Efforts — Let’s Ask USDA Secretary to do the Same!

Interior Secretary nominee Ryan Zinke

During his confirmation hearing Ryan Zinke, nominated to be the new Secretary of Interior, committed to several senators that he would explore ways to better manage invasive species on federal lands – especially in National parks – and to strengthen the National Invasive Species Council (NISC).

Mr. Zinke is currently a Congressional Representative from Montana. Senator Debbie Stabenow (MI) pressed him on invasive species issues during the hearing, focusing on the threat to the Great Lakes of carp and other aquatic species. Also, Senators Al Franken (MN), Joe Manchin (WV), and Mazie K. Hirono (HI) asked about invasive species in written questions submitted to the nominee.

Mr. Zinke answered most questions the same way:  He shares the Senator’s concern, especially since  Montana has significant invasive species problems. Also, he thinks it is critical that federal land managers be encouraged and empowered to be good neighbors in controlling invasive species in cooperation with adjacent private land owners. …  Specifically he wants to explore ways to implement the Early Detection Rapid Response Framework adopted by NISC in 2016.

 

* Sen. Franken included a single question on bioinvaders among a long list of questions on other topics. He mentioned the emerald ash borer as one example of a damaging invader in Minnesota. Senator Franken asked Mr. Zinke:

1) what steps he would take to enhance invasive species control on public lands

See paragraph above for Mr. Zinke’s answer.

2) whether he would enforce the Lacey Act and explore ways to strengthen it.

Mr. Zinke said he would enforce the law. He is aware that there is broad bipartisan frustration with the lack of an efficient process for listing injurious species under the Act. He would ask the Fish and Wildlife Service to recommend ways to improve its implementation. If legislative changes might be helpful, he would be pleased to have that conversation with the Congress.

 

* Sen. Manchin’s first question (!) asked how Mr. Zinke might strengthen NISC to help manage invaders across multiple types of land ownership. See Mr. Zinke’s frequent reference to his Montana experience above for his answer.

 

* Sen. Hirono asked five questions pertaining to invasive species! Her first question concerned steps to protect National parks (especially in Hawaii) from bioinvasion. Here, Mr. Zinke gave his usual response but added: “I am especially concerned that Hawaii’s unique flora and fauna are vulnerable to invasive species. I would not want to see invasive species push any of these unique plants and animals onto the Endangered Species list. Once confirmed, I will ask the National Park Service to present me with options for better protecting our national parks from invasive species.”

 

Ms. Hirono also asked about strengthening NISC. Mr. Zinke responded as follows: “…, I will explore ways to improve the operations of the National Invasive Species Council, and actively engage with the Secretaries of Commerce and Agriculture to get off to a strong start on this issue. … We also need to create a more effective linkage between the National Invasive Species Council policy operation in Washington, DC, and the on the ground federal land managers across the country who deal with invasive species on a daily basis…”

 

Also, Sen. Hirono asked for Mr. Zinke to help Hawai`i and other U.S. Pacific islands to counter the spread of invasive species through movement of military equipment. Mr. Zinke said he would work to enhance coordination with the Department of Defense and the Pacific island communities to reduce the risks posed by invasive species. … explore how we may implement the recent framework for early detection and rapid response …

 

Mr. Zinke also promised to work with Senator Hirono on several issues under Interior jurisdiction that are priorities for Hawai`i, among them invasive species.

 

 

What We Should Ask the new President & Congress to Do re: Invasive Species

While there are many opportunities for the Congress to strengthen U.S. invasive species programs (see my blog from December 31 here, the most important activity NOW is the confirmation of Sonny Perdue as Secretary of Agriculture. Contact your Senators and urge them to ask Governor Perdue how he will address invasive species challenges.

USDA Secretary nominee Sonny Perdue

Possible questions:

Q: How serious do you think is the threat to American natural resources from invasive (non-native) insects, pathogens, and plants? Can you suggest steps you would take to strengthen the efforts of the Animal and Plant Health Inspection Service (APHIS) aimed at controlling introduction and spread of such bioinvaders into the United States?

Q: The principal legal authority for preventing introductions of invasive plants and plant pests is the Plant Protection Act. The PPA provides strong authority but its implementation has been hampered by internal USDA decisions. How would you ensure that the Department corrects these problems and actively enforces its regulations aimed at ensuring the health and productivity of America’s plant resources?

  • In recent years, more than 20 previously undetected plant pests have been detected in the country each year. Hundreds of shipments of goods entering the country each year contain plant pests. What strategies would you promote to reduce the introduction, spread, and impacts of invasive species?

Q: Given the ever-tightening budget allocated to agencies responsible for addressing invasive species threats, what steps would you take to ensure that our country does not suffer waves of new invasions?

If you have a working relationship with your Senators and believe they understand the invasive species issue fairly well, you might want to suggest more detailed questions:

Q: As you know, the Animal and Plant Health Inspection Service (APHIS) is responsible for preventing introduction and spread of plant pests.

  • In some cases, APHIS has been hesitant to use its authority to penalize importers which routinely receive shipments that violate plant pest (phytosanitary) regulations. [You might cite my blog from last week  which illustrates examples pertaining to wood packaging.] Will you instruct APHIS to use its legal authority to impose civil penalties to deter continuing violations?

 

  • Trying to prevent pest introductions by increasing the percentage of shipments that are inspected visually will not be effective in many cases. This is true especially with regard to one of the most important pathways by which plant pests are introduced – imports of living plant material such as nursery stock. APHIS began updating its regulations governing plant imports nearly four years ago, but the proposed new regulations have been not been finalized. Will you look into the reasons for delay and take steps to update these regulations to focus on pathway cleanliness rather than continue to rely on ineffective visual inspections?

Q: Urban forests across the country are under threat from a growing number of non-native or introduced insect pests. Examples include the emerald ash borer – now found in 27 states; Asian longhorned beetle – which threatens a large proportion of urban trees across the country; and polyphagous and Kuroshio shot hole borers – killing many trees in southern California.

Urban forests are at particularly high risk of infestation by non-native pests because they are growing near ports and other transportation hubs where such pests are first introduced. Furthermore, each individual tree in an urban setting provides important benefits in the form of shade, moderation of storm water runoff, abatement of air pollutants, enhanced property values, and neighborhood amenities.

  • Will you fully utilize the authorities under the Plant Protection Act to help ensure the health and productivity of America’s urban forests?
  • [If you have not already suggested the questions outlined above re: wood packaging and other pathways, you might suggest them in this context.]

 

The Secretary of Agriculture also oversees the Forest Service. Pertinent questions:

Q: Invasives are as great a threat to eastern forests as wildfires are in the West. Despite the growing damage and ecological destruction we are witnessing the budgets for research on strategies to minimize these bioinvaders’ impacts are actually falling. How will you work to provide solutions to this quandary?

As I said in my blog at the end of December, what is missing is a political demand for action – and support for necessary staff and funding. Agencies under the secretaries of Agriculture and Interior bear most of the responsibility for managing invasive species. As long as these officials are not being pressed by key Congressional committees, the media, and key stakeholders to take more aggressive and effective action to curtail species introductions and suppress established populations of bioinvaders, they will continue to focus their attention on issues that do generate these kinds of political pressure.

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

 

Invasive insects cause tens of billions in damage

1324067

Formosan subterranean termite damage to a house in New Orleans; observed by Ed Freytag & Alan Lax; photo by Scott Bauer, USDA Agricultural Research Service; bugwood.org

A recent study documents the high costs imposed by invasive insects worldwide.  The study, by Bradshaw et al. (source with link is at the end of this post) concluded that invasive insects cause at least $77 billion (US) in damage every year. This figure includes costs of $70 billion in estimates of damaged goods and service; and $6.9 billion in associated health costs.

What is more, this figure is “grossly underestimated” for a number of reasons:

  • There were few studies providing cost estimates. The authors started by reviewing more than 700 articles, but found that only 158 yielded usable economic estimates.
  • Most of the studies applied to North America and Europe; much of the globe is not included.
  • Ecosystem services eroded by invasive pests are rarely quantified.
  • The health cost estimate does not include the impact of malaria (in most areas, the vector is native rather than invasive), the Zika virus, or economic losses in tourism or productivity (these latter were too difficult to calculate).

While the most destructive of the insects identified in the reports was the Formosan subterranean termite, Bradshaw et al. question some of the economic data included in the single report on the termite. The most damaging insect for which they found “reproducible” economic estimates is the diamondback moth, a voracious consumer of cruciferous crops worldwide.

Other invasive insects cited as being associated with high damage levels are tree-killing pests familiar to readers of this blog: the brown spruce longhorn beetle, the European gypsy moth in North America, and the Asian longhorned beetle (write-ups on all three species can be read here. In my view, the high ranking of these insects reflects a (welcome!) effort by researchers to quantify tree pests’ impacts; although damages caused by agricultural pests are more easily reduced by pesticide applications.

The situation is likely to worsen in the future. According to the authors, climate change, rising human population densities, human mobility, and intensifying international trade will allow these costly insects to spread into new areas. Still, substantial savings could be achieved by increasing surveillance, containment and public awareness (my emphasis).

In an interview with Agence France Presse, one of the coauthors, Franck Courchamp said the best way to combat this growing threat — spread mainly through international commerce — is not more pesticides. Instead, “The solution is better ‘bio-security’,” he said. “This includes inspection of ship and air cargo from certain regions, legislation to ensure that high-risk imports must be treated and rapid eradication of new incursions.” (Interview is posted at http://www.bangkokpost.com/news/world/1102417/invasive-insects-cause-tens-of-billions-in-damage-study)

 

Source

Bradshaw, C. J. A. et al. Massive yet grossly underestimated global costs of invasive insects. Nat. Commun. 7, 12986 doi: 10.1038/ncomms12986 (2016). (Open access)

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

What the new President & Congress Can Do re: Invasive Species

 White House

 

A new President and Congress take office in January.  And outgoing President Obama recently amended the Executive Order on invasive species.

What might the new leaders do to improve America’s invasive species programs?

Here are a group of actions that I think would improve programs significantly:

  • amend the Lacey Act to strengthen controls over introduction and spread of invasive animals and animal diseases;
  • raise the political profile of invasive species issues by holding more frequent oversight hearings;
  • increase funding for invasive species prevention, containment, and control programs;
  • support proposals to amend the 2019 Farm Bill to strengthen on-the-ground programs, policies, and research aimed at minimizing invasive species introduction, spread, and damage;
  • during the confirmation process, Senators should ask President Trump’s nominees to leadership positions in the Departments of Agriculture and Interior about how they will address invasive species challenges.

Do we need new legislation mandating that federal land-managing agencies do X or Y with regard to invasive species? This was the focus of a hearing in May at which I testified.

Federal land-managing agencies are already authorized and – in some cases required – to act to control invasive species on lands and waters under their jurisdiction.  Some of the existing statutes even authorize the agencies to apply fees paid by people who use the public lands for some purpose (e.g., livestock grazing, recreation) to management of invasive species.

Most of the statutes authorizing invasive species management incorporate that activity into the agency’s broader management goals for protection of wildlife, habitat, natural resources, historic or cultural sites, etc.  For example, the USFS Manual §2900 lists 21 laws and 6 regulations or policies that govern the USFS’ management of invasive species.  Some of these laws apply to all federal land-managing agencies, including:

  • Endangered Species Act (ESA) of 1973 (16 U.S.C. §§1531 et seq.)
  • Surface Mining Control and Reclamation Act of 1977 (30 U.S.C. 1201, 1201 (note), 1236, 1272, 1305). §515
  • North American Wetland Conservation Act 1989 (16 U.S.C. 4401 (note), 4401-4413, 16 U.S.C. 669b (note)). §9 [U.S.C. 4408]
  • Sikes Act (Fish and Wildlife Conservation) of September 15, 1960 (16 U.S.C. 670g-670l, 670o, P.L. 86-797), as amended. §201
  • National Historic Preservation Act of 1966 [16 U.S.C. §§470 et seq.]
  • Wilderness Act of 1964 (16 U.S.C. §§1131 et seq.

Other statutes apply only to resource management authorities of the USDA Forest Service; these include:

  • Organic Administration Act of 1897 (16 U.S.C. §§ 473 et seq.).
  • Fish and Wildlife Coordination Act (16 U.S.C. § 661 et seq.).
  • Knutson-Vandenberg Act of June 9, 1930 (16 U.S.C. 576, 576a-576b). §3 [16 U.S.C. 576b]
  • Bankhead-Jones Farm Tenant Act of 1937 (7 U.S.C. §§1010 et seq.)
  • Anderson-Mansfield Reforestation and Revegetation Act of October 11, 1949 (16 U.S.C. 581j (note), 581j, 581k)
  • Multiple-Use Sustained-Yield Act of 1960 (16 U.S.C. §§528 et seq.)
  • Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 as amended by the National Forest Management Act (NFMA) of 1976. §6
  • International Forestry Cooperation Act of 1990 (16 U.S.C. § 4501)
  • Healthy Forests Restoration Act of 2003 (H.R. 1904), [16 U.S.C. 6501-6502, 6511-18, 6541-42, 6571-78]
  • Wyden Amendment (P.L. 109-54, Section 434).
For brief descriptions of all these statutes, see the references and links at the end of this blog posting.

Advocates have tried before to legislate a specific requirement that federal agencies combat invasive species.  The Federal Noxious Weed Act of 1974 (7 U.S.C. § 2801 note; 7 U.S.C. § 2814) was amended in 1990 to add §15, “Management of Undesirable Plants on Federal Lands”.  This section requires each federal agency to

1) designate an office or person adequately trained to develop and coordinate an undesirable plants management program for control of undesirable plants on federal lands under the agency’s jurisdiction, and

2) establish and adequately fund an undesirable plants management program through the agency’s budgetary process,

3) complete and implement cooperative agreements with state agencies regarding the management of undesirable plant species on federal lands, and

4) establish integrated management systems to control or contain undesirable plant species targeted under cooperative agreements.

This approach hasn’t worked – no one is satisfied by the federal agencies’ “weed” management efforts.

 

Capitol

What is missing is a political demand for action – and support for necessary staff and funding. Agencies under the secretaries of Agriculture and Interior bear most of the responsibility for managing invasive species.  As long as these officials are not being pressed by key Congressional committees, the media, and key stakeholders to take more aggressive and effective action to curtail species introductions and suppress established populations of bioinvaders, they will continue to focus their attention on issues that do generate these kinds of political pressure.

I am not saying that the principal statutes governing invasive species management could not be improved.  As noted above, several proposals have been put forward to strengthen laws which are the foundation for preventing introduction of invasive species.  I will blog about specific proposals in the new year.

 

Sources

USFS Invasive Species Manual

ANSTF/NISC report “Federal Policy Options Addressing the Movement of Aquatic Invasive Species Onto and Off of Federal Lands and Waters. 2015.  Committee on the Movement of Aquatic Invasive Species both onto and off of Federal Lands and Waters.

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

CISP files multi-species listing petition with US Fish & Wildlife Service – per Lacey Act

 

 

alburnus_alburnus_01_by-dpc

Alburnus alburnus photo by David Perez

Update as of December 7, 2016: the Petition was amended to delete one species red swamp crayfish (Procambarus clarkia), for which we decided it needed more analysis.  We will consider whether to re-propose it for an “injurious species” listing and/or other measures later

Last Friday morning, I delivered a Petition to the Secretary of the Interior’s office the roots of which go back 15 years to 2001. The title: Petition: To Amend 50 CFR §16.13 to List 43 High Risk Fish, Crayfish, and Mollusk Species as Injurious Species under the Lacey Act. (For a copy of the petition, use the “contact us” button on the CISP webpage.) I was really excited to file this on CISP’s behalf because it is the logical expansion of a more proactive approach to preventing introductions of invasive, disease-carrying, or otherwise “injurious” non-native animals that we don’t want running around in the United States. We already have scores of invaders (starlings, red lionfish, Burmese pythons, feral hogs, Asian carps, zebra and quagga mussels, tegus and on and on). We need to start doing multi-species listing proposals in order to change what has been an extremely slow process into one that works at a pace that can actually protect our nation’s resources – and people – from the risks of this age of vast globalized trade in live fish and wildlife.

 

Back in 2001, the National Invasive Species Council adopted its first Management Plan. One element in it was to adopt a science-based screening method aimed at identifying the highest risk non-native animals that we should keep out of the country.  This was to have been completed by about 2006.  I was appointed long ago (so far back I can’t remember the year) to the committee tasked with this responsibility.  The Committee went through fits and starts and sometime in the mid-2000s just crashed into nothingness and stopped meeting.  But, a dedicated U.S. Fish and Wildlife Service (FWS) biologist in the Midwest Region — Mike Hoff — kept at it for years on a shoestring budget and around 2011 he got some real funding and was able to get his animal screening project staffed. Lo and behold, they started developing lists of high-risk species based on robust scientific predictions. I won’t go into the models he used and the peer-review he had to go through. Suffice it to say that process took about 3 more years before Mike Hoff and his colleagues could convince the FWS to actually start publicly posting the results of their screening work. But, starting in 2014 they posted several and in late 2015 they posted them in earnest. Now there are 150 Ecological Risk Screening Summaries (ERSSs) on the bureau’s website.

 

Out of the 150 species, 63 pose a “high” overall risk of invasiveness/injuriousness.  For funding and historical reasons most are aquatic species that could invade in the Great Lakes region, but even so it is a great beginning. The 63 species include 46 fishes, 8 crustaceans, and 9 mollusks. One fish on the website (mrigal, Cirrhinus cirrhosus) appears to be labeled “high risk” in error and one of the mollusks (zebra mussels, genus Dreissena) is already listed under the Lacey Act. Also, Interior already has formally proposed that 11 of the 63 species on the website should be listed as “injurious”. That is, almost exactly one year ago the agency proposed to add 10 of the non-native fish and one crustacean. Thus, those 11 are not included in this new Petition. The FWS needs to take action on them soon.

 

UPDATE: On Sept. 29th the FWS finalized its rule listing all 11 of those species. The regulation and the detailed FWS explanation for it published in the Federal Register set a strong precedent and a useful template for listing the 43 species in the Petition as well.

 

Now this Petition, which I co-wrote with my CISP colleague Phyllis Windle, PhD., should be the USFWS’ next multi-species listing. The 43 “high risk” species proposed in it are listed at the end of this blog. The Petition excludes 7 species with posted ERSSs that were “high: overall,” but were below a high rating for either their history of invasiveness or climate match. As a result, the 43 below represent the highest range of the FWS’s identified high risks. Species like the Devil firefish, virile crayfish and the bleak – just their names makes me not want them here – pose unacceptable risks.

 

While the voluntary program promoted by the FWS on its webpages along with the ERSSs is a commendable hope, a “please do not import” approach cannot be relied upon. Administrations and websites change and some industry outliers won’t follow voluntary measures anyway – some even see them as creating a business opportunity. As I have watched (and supported), Mike Hoff and the FWS invested a significant amount of funds and staff time over the last 10 years to develop this screening process and research and write the scores of posted ERSSs. Other experts were involved in designing the process and providing peer reviews at different stages. It would be a significant waste of taxpayer resources were the FWS not to follow through and take regulatory action for species posing a clearly high risk. None offers an essential benefit that outweighs its harm to the United States. Minimal to zero stakeholder opposition is expected to prohibiting them. So what are we waiting for? The listing Petition needs to get posted in the Federal Register for public comment and action started as soon as possible. This one is virtually a “no brainer”.

 

The proposed list additions are below. For a copy of the full Petition, use the “contact us” button the the CISP webpage.

 

Mollusks

(A) Bithynia tentaculata (faucet snail).

(B) Corbicula fluminea (Asian clam).

(C) Dreissena rostriformis bugensis (Quagga mussel).

(D) Limnoperna fortune (golden mussel).

(E) Potamopyrgus antipodarum (New Zealand mudsnail).

(F) Sinanodonta woodiana (Chinese pond mussel).

 

Fish

(A) Acanthogobius flavimanus (yellowfin goby).

(B) Alburnus alburnus (bleak).

(C) Alosa pseudoharengus (alewife).

(D) Cichlasoma bimaculatum (black acara).

(E) Coregonus lavaretus (powan).

(F) Ctenopharyngodon idella (grass carp).

(G) Cyprinella lutrensis (red shiner).

(H) Cyprinus carpio (common carp).

(I)  Gymnocephalus cernua (ruffe).

(J)  Hypomesus nipponensis (wakasagi).

(K) Ictalurus furcatus (blue catfish).

(L)  Misgurnus anguillicaudatus (Oriental weatherfish).

(M) Morone americana (white perch).

(N) Neogobius melanostomus (round goby).

(O) Odontesthes bonariensis (Argentinian silverside).

(P) Oreochromis aureus (blue tilapia).

(Q) Oreochromis mossambicus (Mozambique tilapia).

(R) Oreochromis niloticus (Nile tilapia).

(S) Parachromis managuensis (Jaguar guapote).

(T) Poecilia reticulate (guppy).

(U) Pterois miles (Devil firefish).

(V) Pterois volitans (red lionfish).

(W) Pterygoplichthys pardalis (Amazon sailfin catfish).

(X) Pterygoplichthys multiradiatus (Orinoco sailfin catfish).

(Y) Pterygoplichthys disjunctivus (vermiculated sailfin catfish).

(Z) Pylodictis olivaris (flathead catfish).

(AA) Rhodeus ocellatus (rose bitterling).

(BB) Sarotherodon melanotheron (blackchin tilapia).

(CC) Scardinius erythrophthalmus (rudd).

(DD) Tilapia mariae (spotted tilapia).

(EE) Tilapia zillii (redbelly tilapia).

 

Crayfish

(A) Oronectes limosus (spiny-cheek crayfish).

(B) Oronectes propinquus (northern clearwater crayfish).

(C) Oronectes rusticus (rusty crayfish).

(D) Oronectes virilis (virile crayfish).

(E) Pacifastacus leniusculus (signal crayfish).

(F) Procambarus clarkia (red swamp crayfish).

 

Posted by Peter Jenkins

Invasive Earthworms Need Action!

 worm_medAmynthes agrestis; National Park Service photo

 

Earthworms have been largely ignored as a class of invaders. But evidence is accumulating that their numbers and impacts are too significant to ignore.

 

Non-indigenous earthworms began arriving in the Americas with the first European colonists and they are now widespread. One study (see summary of Reynolds and Wetzel 2008 here) found 67 introduced species among the 253 earthworm species in North America (including Mexico, Puerto Rico, Hawaii, and Bermuda).  In Illinois, 20 of the 38 species are introduced. Nuzzo et al. 2009 recorded a total of 11 earthworm species – all nonnative – at 15 forest sites in central New York and northeastern Pennsylvania.

 

Earthworms are good invaders – they reproduce quickly and are easily transported to new places – both carelessly and deliberately for bait, composting, or other uses.

 

As ecosystem engineers, invasive earthworms cause significant impacts to the soil and leaf litter, as well as to plants and animals dependent on those strata.  However, they are little studied and few efforts been made to address their threat.  Wisconsin is the pioneer (see below).

 

Ecosystem Engineers: Impacts on Soil, Plants, and Animals

 

Invasive alien earthworms cause enormous damage in forest environments. (I have seen no information about the damage they might cause in other natural systems.)  Earthworms can change soil chemistry, soil structure, and the quantity and quality of the litter layer on the soil surface. Changes include rapid incorporation of leaf litter into the soil, alteration of soil chemistry, changes in soil pH, mixing among soil layers, and increased soil disturbance. Such changes have been shown to harm native plant species – both herbaceous ones on the forest floor as well as the regeneration of woody vegetation, including trees.  See the review just published by Craven et al. 2016 and Hale and Nuzzo references below).

 

Craven et al. (2016) conducted a meta-analysis of 645 observations in earlier publications. They sought to measure the effects of introduced earthworms on plant diversity, cover of plant functional groups, and cover of native and non-native plants. Sites with a higher the diversity of invading earthworms – with associated variety in behaviors (see below) – had greater declines in plant diversity.  Higher earthworm biomass or density did not reduce plant diversity but did change plant community composition:  cover of sedges and grasses and non-native plant species significantly increased, and cover of native plant species (of all functional groups) tended to decrease. The increase in non-native plant cover in areas with higher earthworm biomass is thus an example of ‘invasional meltdown’ as propounded by Simberloff and Von Holle in 1999.

 

Craven et al. 2016 propose several direct and indirect mechanisms by which introduced worms might affect plant species. These include ingestion of seeds or seedlings, burying seeds, and alteration of water or nutrient availability, mycorrhizal associations, and soil structure. European and Asian plant species that co-evolved in the presence of earthworms could better tolerate earthworms’ presence.

 

Important Questions

 

Craven et al. 2016 note that the interaction of the invader-related factors with other site-related conditions such as deer browsing, fire history, forest management, and land-use history require further study to disentangle. Many other questions need to be answered, too.


Although Craven et al. (2016) do not specify the geographic range of the studies analyzed, I believe most were conducted in the northern and northeastern regions of the United States and some parts of Canada. It would be interesting to see if these studies’ findings differed from those carried out in Great Smoky Mountains National Park on the Tennessee-North Carolina border. The latter is an area where – unlike the northern states – earthworms were not wiped out by the most recent glaciation.  (See references by Bruce Snyder and Jeremy Craft, below.)

 

The finding that worm species diversity is associated with decreased plant species diversity seems to indicate that worms’ impacts might vary depending on the behavior of the worm in question – especially whether the worms remain on or near the soil surface and — if not — how deeply they burrow.  Are studies under way to clarify these differences?

 

Furthermore, do the impacts of European worms – the subjects of most of the studies carried out in Minnesota, New York, and Pennsylvania – differ substantially from the impacts of Asian earthworms? Or are any differences explained better by the species’ activity in the soil (e.g., depth of burrows) than their origins?

 

Impacts of earthworms on wildlife are less studied and perhaps less clear.  Several studies have focused on salamanders because of their known dependence on leaf litter. In a study of 10 sites in central New York and northeastern Pennsylvania, Maertz et al. 2009 found that salamander abundance declined exponentially with decreasing volume of leaf litter. They suggested that the salamander declines were a response to declines in the abundance of small arthropods, a stable resource.

A study by Ziemba et al. (2016) in Ohio involved Asian worms (genera Amynthas and Metaphire) rather than the European worms most often included in studies carried out in Minnesota, New York, and Pennsylvania.  These authors found a complex picture: earthworm abundance was negatively associated with juvenile and male salamander abundance, but had no relationship with female abundance.

Craft (2009) found that reduced leaf litter mass in invaded areas of Great Smoky Mountains National Park diminished habitat for both salamanders and salamander prey.

Others have studied millipedes – a largely unappreciated example of biological diversity in the Southern Appalachian Mountains – in Great Smoky Mountains National Park. Snyder and colleagues (2013) found that earthworms in the genus Amynthas altered soils by decreasing the depth of partially decomposed organic horizons and increasing soil aggregation. The result was a significant decrease in millipede abundance and species richness – probably as a result of competition for food.

Results from a study of earthworms’ effects on the Park’s food web by Anita Juen and Daniela Straube, begun in 2010, have not yet been published (pers. comm. from GRSM staff).

Even birds might be affected by worm invasions. One study in Wisconsin found that hermit thrush and ovenbird populations are lower in areas infested by worms. Possible reasons for the decline are that nests (on the ground) are more vulnerable to predation when located in the grasses promoted by worms, and a reduction in invertebrates fed to nestlings.

 

Expanding Risks

Several non-native earthworm species have been collected (so far) only from greenhouses or other places of indoor cultivation.  But can we be sure that they are not being spread to yards, parks, and other places halfway to natural systems through movement of plants and mulch?

 

Earthworms are extremely difficult to manage once established.

Are these challenges the reasons why few official efforts to control earthworm spread have been adopted? Or is it the animals’ public image – they are widely regarded as “good” critters that enrich the soil and facilitate composting. Or is it that trying to control worms will require enhanced regulation of the nursery and green waste industries?

worms1Amynthes photo; from Wisconsin DNR website

Wisconsin Is the Policy Pioneer

Wisconsin stands out for trying to address the issue! The state’s conservation and phytosanitary officials became alarmed when they detected Amynthas species in the University of Wisconsin Arboretum in 2013.  This is the site of regular plant sales,a likely pathway for spread.  Wisconsin now knows this genus of worms to be present in 21 counties, mainly along urban corridors.  They have not yet been found in the state’s forests.

Wisconsin is acting to protect its forests despite Amynthas worms having been present in the United States for over a century: Snyder, Callaham and Hendrix 2010 say several species of Amynthas were documented in Illinois and Mississippi by the 1890’s.  Some 15 species are recorded as established and widespread across the eastern United States (Reynolds and Wetzel 2004).

 

Wisconsin has classified the Amynthas genus as “restricted” – so their movement is now regulated. The risk of spread appears to be greatest through mulch produced from leaves collected in residential communities. The state held a workshop during which the regulated industry developed best management practices to address that risk. The Wisconsin Department of Natural Resources has posted a web page with information about identifying the worms and the BMPs. (Wisconsin DNR has also been a leader in tackling the firewood pathway.) The Wisconsin Department of Agriculture put the worm issue on the agenda of the National Plant Board in August 2016 and urged other states to take action.

The Wisconsin DNR webpage has

  • ID cards and other information to aid identification, g., photos of worms and the “coffee ground” soil they create;
  • a brochure with the state’s new “best management practices”
  • educate yourself and others to recognize jumping worms;
  • watch for jumping worms and signs of their presence;
  • ARRIVE CLEAN, LEAVE CLEAN – Clean soil and debris from vehicles, equipment and personal gear before moving to and from a work or recreational area;
  • only use, sell, plant, purchase or trade landscape and gardening materials and plants that appear to be free of jumping worms; and
  • only sell, purchase or trade compost that was heated to appropriate temperatures and duration following protocols that reduce pathogens.

What’s Up Where You Are?

What is your state doing to slow the spread of invasive earthworms?

  • Do nursery inspectors look for earthworms when approving plant shipments? Craven et al. 2016 findings re: higher impacts on plants as number of worm species rises demonstrate the importance of slowing spread of new species even into areas that already have some non-native earthworms.
  • Are professional associations of nurserymen and green waste recyclers educating their members about the damage caused by invasive earthworms and steps they can take to minimize worms’ spread to new areas?
  • Are organizations of anglers and gardeners in your state educating their members about the damage caused by invasive earthworms and steps they can take to minimize worms’ spread to new areas?
  • Are ecologists studying earthworm invasion impacts in other parts of the country? In non-forested ecosystems?
  • Are conservation organizations initiating or joining outreach efforts?
  • Can worm-education efforts be joined with h more robust public and private outreach focused on aquatic invaders, invasive plants, or firewood?

 

SOURCES

Bohlen, P.J., S. Scheu, C.M. Hale, M.A. McLean, S. Migge, P.M. Groffman, and D. Parkinson. 2004.  Non-native invasive earthworms as agents of change in northern temperate forests. Front Ecol Environ 2004; 2(8): 427–435

Craft, J.J. 2009. Effects of an invasive earthworm on plethodontid salamanders in Great Smoky Mountans National Park. Thesis prepared at Western Carolina University.

Craven, D., M.P. Thakur, E.K. Cameron, L.E. Frelich, R.B. Ejour, R.B. Blair, B. Blossey, J. Burtis, A. Choi, A. Davalos, T.J. Fahey, N.A. Fisichelli, K. Gibson, I.T. Handa, K. Hopfensperger, S.R. Loss, V. Nuzzo, J.C. Maerz, T. Sackett, B.C. Scharenbroch, S.M. Smith, M. Vellend, L.G. Umek, and N. Eisenhauer. 2016.The unseen invaders: intro earthworms as drivers of change in plant communities in No Am forests (a meta-analysis). Global Change Biology (2016), doi: 10.1111/gcb.13446 available here.

Hendrix, P.F. 2010. Spatial variability of an invasive earthworm (Amynthas agrestis) population and potential impacts on soil characteristics and millipedes in the Great Smoky Mountains National Park, USA. Biological Invasions DOI 10.1007/s10530-010-9826-4

Maertz, J.C., V. Nuzzo, B. Blossey.  2009. Declines in Woodland Salamander Abundance Associated with Non-Native Earthworm and Plant Invasions. Conservation Biology Volume 23, Issue 4 August 2009  Pages 975–981

Nuzzo, V.A., J.C. Maerz, B. Blossey. 2009. Earthworm Invasion as the Driving Force Behind Plant Invasion and Community Change in Northeastern North American Forests. Conservation Biology Volume 23, Number 4, 966-974.

Simberloff, D.  and Von Holle, B. 1999. Positive interactions of nonindigenous species: invasional meltdown? Biological invasions 1, 21-32

Snyder, B.A., M.A. Callaham, C.N. Lowe, P.F. Hendrix. 2013. Earthworm invasion in North America: food resource competition affects native millipede survival and invasive earthworm reproduction. Soil Biology and Biochemistry 57, 212-216

Ziemba JL, Hickerson C-AM, Anthony CD. 2016. Invasive Asian Earthworms Negatively Impact Keystone Terrestrial Salamanders. PLoS ONE 11(5): e0151591. doi:10.1371/journal.pone.0151591

 

See also:

Global picture: https://www.newscientist.com/article/mg19325931-600-war-of-the-worms/

Great Lakes Wormwatch website: http://www.nrri.umn.edu/worms/research/publications.html  

Illinois Natural History Survey webpage: http://wwn.inhs.illinois.edu/~mjwetzel/IllinoisEarthworms.html

Wisconsin  DNR http://dnr.wi.gov/topic/invasives/fact/jumpingWorm/index.html

Information on western Canada:

http://bcinvasives.ca/news-events/recent-highlights/earthworm-invasion-calling-all-citizen-scientists/

http://ibis.geog.ubc.ca/biodiversity/efauna/EarthwormsofBritishColumbia.html

Native Earthworms of British Columbia Forests: http://www.cfs.nrcan.gc.ca/pubwarehouse/pdfs/5102.pdf

 

Posted by Faith Campbell

When will invasive species get the respect they deserve from conservationists?

i`iwi birdblogger i`iwi in Hawai`i

photo from www.TheBirdBlogger.com; used with permission

 

Evidence is growing that invasive species are among THE major threats to conservation goals worldwide.

In 2015 the IUCN called invasive species the second most significant threat to those World Heritage sites around the world that have outstanding natural values. (Poaching is the greatest threat.) My October 21, 2015 blog showed that the IUCN report actually underestimated the impact of invasive species. I listed briefly the principal invaders in several U.S. National parks. Earlier blogs criticized the National Park Service for failing to regulate the movement of firewood (August 2015) and described the invasive threat to Hawai`i (earlier in October 2015).

Now a second study shows invasive species are a principal driver of species extinction. The authors assessed the prevalence of alien species as a driver of extinctions among plants, amphibians, reptiles, birds, and mammals (which are the best-studied taxa) post-1500 AD. Overall, 58% of extinct or extinct-in-the-wild species had been driven to extinction at least in part by invasive species. Invasive alien species are the second most common threat overall. Indeed, invasive species are the most common threat for vertebrate extinctions (62% of extinct or extinct-in-the-wild species faced threats from invasive species). Invasive species ranked fourth as a cause of extinction for plants: 27% of listed plant species were threatened by invasive species.

For those species with just a single driver of extinction, invasive species is the cause for 47% of mammals, 27% of birds, 25% of reptiles, and 17% of plants. In no case were invasive species identified as the sole threat to an amphibian species – although invasive species are their second highest threat.

Although the paper lists invasive species as second, their threat was virtually identical to that of “overexploitation”, the threat ranked first. That is, 124 out of 215 species studied were threatened at least in part by invasive species; 125 were threatened by overexploitation.

Other principal threats were overexploitation, agriculture, aquaculture, and – in the case of plants – residential and commercial development. Categories related to habitat loss ranked surprisingly low. Only 61 of the 215 cases listed agriculture and aquaculture as threats.

The authors reflect on whether invasive species are not themselves causal agents of extinction, but rather symptoms of the real causes, especially habitat destruction. They conclude that that is unlikely.

Instead, they suggest that invasive species impacts might often be underestimated, as many interactions – especially those between alien parasites and native hosts – are very hard to detect.

Not surprisingly, 86% of island endemic species had invasive species as one extinction driver. Nevertheless, continental organisms are also threatened — 14% of alien-related extinctions have been of species with mainland populations. These include eight amphibians, five birds, and six mammals. Most of these invader-threatened mainland organisms are from the Americas

Among the approximately 30 alien taxa named as extinction drivers are rats, cats, and trout as threats to other vertebrates such as birds and mammals. All three were also ranked highly as damaging invasives in the earlier IUCN report on World Heritage sites. Diseases – especially chytridiomycosis and avian malaria – were causal agents of extinction for amphibians and birds. Several herbivores – especially goats, sheep, and European rabbits – and alien plants were drivers of extinction for plant species.

Of course, outright extinction is not the only damage to biological diversity caused by invasive species. American chestnut, Fraser fir, and redbay are not extinct, but their ecological role has been virtually eliminated as the vast majority of these forest trees die off. Other tree taxa are on same road – ash and eastern hemlocks across wide expanses of their ranges; tanoaks; whitebark pines …

Invasive species pose major threats to biological diversity and other conservation goals. These damages are on top of the acknowledged threat of invasive species to agriculture, forestry, or economic groups. (See, for example, Lovett et al. 2016 discussed in my previous blog.) The role of invasive species in extinction described in this new paper suggest a long-standing bias among conservationists’ priorities. Too often, we have focused on species threatened by overexploitation – which is such easier to see and involves an obvious “villain”.

Nevertheless, a host of practical suggestions have been put forward to address the root causes of species introductions and spread. Often, these ask some or many of us to stop doing what we have been doing. But much meaningful conservation action requires someone to accept limits or to make sacrifices.

Will the conservation community – including grant-making foundations, federal and state agencies, and the many conservation non-governmental organizations ranging from the IUCN to local groups – now take up the challenge of implementing suggested actions and actively advocating for the funding needed for practical steps that will begin to bring this threat under control?

 

Sources

Bellard C, Cassey P, Blackburn TM. 2016 Alien species as a driver of recent extinctions. Biol. Lett. 12: 20150623. http://dx.doi.org/10.1098/rsbl.2015.0623 http://rsbl.royalsocietypublishing.org /

 

Lovett,G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig , F.T. Campbell , J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, S.L. LaDeau, and T. Weldy. 2016. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications, 0(0), 2016, pp. 1–19. DOI 10.1890/15-1176.1

Available at www.caryinstitute.org/tree-smart-trade

 

Posted by Faith Campbell