What Did We Do?! The Biologists’ Role in the Management and Spread of Invasive Species


8:00AM The Biologists’ Role in the Management and Spread of Invasive Species
  Andrea Darracq
Invasive species are one of the greatest threats to biodiversity. Yet, many invasive species issues were caused by biologists, either directly or indirectly. In this presentation, we introduce our symposium “What Did We Do?! The Biologists’ Role in the Management and Spread of Invasive Species”. First, we discuss our roles as biologists in the establishment and/or spread of some invasive species directly and/or by being slow to enact management due to a lack of resources, lack of knowledge on proper control techniques, failure to inform and educate the public regarding invasive species problems, and/or failure to recognize a species would become invasive. Then, we broadly discuss potential solutions to these problems including research, outreach, and policy. Finally, we introduce the case studies highlighted in our symposium in the context of these roles and the potential solutions we have discussed.
8:20AM Agency Use of Asian Carps to Solve Problems and Create More Problems.
  Kevin Irons
Rationale in bringing Grass, Bighead, Silver, and Black carps to the United States are well documented and well debated beginning in the 1960-70s. Biological control in many cases were an answer to concerns with extensive aquaculture and challenges of chemical treatment. Because these species were identified to solving such problems, impacts once these fish escaped and established populations in the US are not surprising. While we can’t turn back time, insights from their native range can help multi-jurisdictional authorities in managing and controlling them and inform management strategies in their native ranges as well. Current efforts in the Illinois Waterway are implementing strategic detection, management and control actions, as well as developing contingency planning to provide for the best management of these species in US waters supported by United States EPA Great Lakes Restoration Initiative support and funding. International coalitions such as the Mississippi River – Yangtze River Basin Symposiums (MYRIBS) have facilitated the understanding of removal methods as well as insights into future control methods here in the US based upon Chinese insights. A management strategy to include efficient harvest, use of deterrents and/or technology will enable management of these species into the future while minimizing ecosystem impacts.
8:40AM Evaluating the Potential Effects of Invasive Aquatic Species Management on Native Fishes
  Stephen Pescitelli
A common management practice for preventing the spread of invasive fish species involves constructing new dams or barriers or maintaining existing ones. However, the deleterious impacts of dams on native fish and mussel diversity are well known. Restoration of fish assemblages remains an on-going need in the Chicago area due to fragmentation and historic water quality degradation. In the Illinois River Waterway several issues have arisen involving trade-offs between restoring native fish assemblages and preventing movement of invasive species. In one case, proposed fish passage on a tributary dam was denied due to the presence of Bigheaded Carps, despite obvious benefits of reconnection to upstream fish assemblages. In another case, a proposed invasive species barrier in a lock system, which is the pinch point for the advancement of Bigheaded Carps towards Lake Michigan, would stall restoration of an urban river system where 36 additional fish species have been recorded since 1976. Recent infrastructure additions have eliminated combined sewer overflows, resulting in increases in both species richness and sportfish abundance, with upstream fish passage through the lock serving as a major source of recruitment. Managers must recognize these trade-offs and mitigate for losses to recovery and maintenance of native fish assemblages.
9:00AM Invasive Carp for Dinner and the Lobsters in Maine Are Hungry
  Nick Popoff
A collaborative effort between Maine, Illinois and the U.S. Fish and Wildlife Service has developed a new outlet for invasive (Asian) carp. The American Lobster (Homarus americanus) fishery in Maine is arguably the most iconic commercial fishery in North America landing 120 million pounds in 2018. This baited-trap fishery has been estimated to use over 100 million pounds of bait, annually. Atlantic Herring (Clupea harengus) is the preferred bait but declining quotas have required alternative and potentially risky bait sources. In 2019, herring quotas were cut by 70% leading to an influx of new bait requests. Alternate bait sources with biomass’s great enough to meet the herring shortage is causing concern for fisherman and Maine regulators. Enter Asian carp, an invasive species wreaking environmental and economic havoc. A 2018 report from Illinois DNR proposed an Asian Carp control goal of 20 – 50 million pounds annually and efforts are underway to find outlets. Risk mitigation such as disease testing, harvest location requirements, and chain of custody forms were developed to facilitate large shipments of carp from Illinois to Maine for lobster bait. Time will tell if this collaboration will positively impact current efforts to manage Asian carp in Illinois.
9:20AM Determinants of Invasive Species Policy: Print Media and Agriculture Determine U.S. Invasive Wild Pig Policy
  Ryan Miller
Conflicts between wildlife, invasive species, and agricultural producers are increasing with most stakeholders agreeing that policies balancing socioeconomic considerations with invasive species management, wildlife conservation, and agriculture are needed. However, the interaction between societal and biological drivers that influence human–invasive species–wildlife policy is poorly understood. We identify factors influencing policy leading to the establishment of a new federal program to control invasive wild pigs in the U.S. We fit generalized linear models relating congressional policy activity to print newspaper media and agriculture. Our models explained 89% of the deviance in policy activity indicating a strong linkage between policy activity and predictors representing the amount of negative news media and amount of agricultural producers impacted by wild pigs. Increases in co-occurrence of agriculture and wild pigs had the largest effect; for every 1% increase in co-occurrence, there was a 41% increase in congressional policy activity. Congressional policy activity addressing livestock increased at twice the rate of policy activity addressing crop agriculture. These results suggest that agriculture and media coverage can act as determinants of invasive species policy. Our approach may provide early insight into emerging policy areas enabling proactive policy development and can support policy and program evaluation.
09:40AM Break
1:10PM Managing Invasive Wild Pigs in North America
  James Beasley
Although invasive wild pigs (Sus scrofa) have been present in North America for several hundred years, there has been a rapid expansion in size and distribution of populations in recent decades. Wild pigs cause substantive damage to ecological and anthropogenic ecosystems, have been implicated in the extinction of endemic species on islands, and are reservoirs for a range of pathogens that can be transmitted to livestock, wildlife, and humans. Many negative impacts have increased concomitantly with expanding pig populations, and thus there is growing interest in the reduction or elimination of populations in many areas. However, invasive pigs are widely pursued as game animals and even managed as a game resource in some states. Therefore, large-scale population reduction will not be possible without a shift in the attitudes and perceptions of wild pigs, as well as unified support among stakeholders. Further, significant knowledge gaps exist regarding the basic biology and ecology of wild pigs, the scope of damage they cause, and efficacy of many control strategies. Here I discuss the broad range of tools, technologies, and strategies available for controlling wild pigs, emphasizing their relative effectiveness and limitations, and point to examples of successful wild pig management where appropriate.
1:30PM Lake Davis, a Northern Pike Eradication Success
  Amber Mouser
Northern pike Esox lucius are a non-native, invasive, predatory fish species that were illegally introduced to California. They had the potential to seriously impact California’s aquatic ecosystems. Northern pike were discovered in Lake Davis, Plumas County, in 1994. In October 1997, after completion of the California Environmental Quality Act (CEQA) process, much public debate, and several court challenges, the California Department of Fish and Game (CDFG) applied the commercial piscicides Nusyn-noxfish® and powdered rotenone to Lake Davis and its tributaries to eliminate northern pike. In May 1999, a northern pike was caught in Lake Davis by an angler. Subsequent sampling again confirmed the presence of northern pike in Lake Davis. In September 2007, again after considerable public involvement and environmental permitting, CDFG conducted a second chemical treatment of all waters within the Lake Davis watershed upstream of Grizzly Valley Dam. This included the lake, its tributary streams, and associated standing water. Immediately following the chemical treatment in 2007 CDFG conducted extensive post-treatment monitoring of fish populations in Lake Davis and its tributaries to determine if the chemical treatment had successfully removed northern pike from the watershed. This poster chronicles the ultimate success of the northern pike eradication efforts.
1:50PM Actions Taken and Lessons Learned Along the Journey – Six Decades of Sea Lamprey Control
  Dale P. Burkett
The sea lamprey, Petromyzon marinus, an incredibly destructive invasive species, entered Lake Ontario in the mid-1800s, and the upper Great Lakes beginning in 1921 where they inflicted significant economic damage, harmed the fishery and ecosystem, and changed the way of life in the region. Of the more than 180 non-native species in the Great Lakes basin, sea lampreys are the only invader controlled basin-wide and the only example in the world of a successful aquatic vertebrate pest control program at an ecosystem scale. The Great Lakes Fishery Commission, pursuant to the Convention on Great Lakes Fisheries, delivers sea lamprey control in partnership with the U.S. Fish and Wildlife Service, Fisheries and Oceans Canada, and the U.S. Army Corps of Engineers. The U.S. Geological Survey conducts critical sea lamprey research to aid in control. This control program has reduced sea lamprey populations by 90% during the past six decades. Successes, setbacks, development of control tools, shifts in social license, shifting baseline syndrome, prognostications about the future, and the challenges of controlling sea lamprey in a multi-jurisdictional environment are explored.
2:10PM Weed or Wonder Plant? the Complexities of Non-Native Hydrilla Management in Florida
  Jeffrey Hill
Management of few non-native species matches the complexity associated with the aquatic macrophyte Hydrilla Hydrilla verticillata. Hydrilla is one of the most widespread aquatic invasive species in the United States. Its fast growth, low light requirements, and propensity to “top-out” led to instances of heavy infestations in lakes, rivers, and canals. At high abundance, Hydrilla can impede boat access, depress dissolved oxygen levels, obstruct flow, and reduce sport fish condition. Due to these effects and concerns over loss of biodiversity, Hydrilla control is a high priority for many states, including Florida. Nevertheless, control programs are costly and controversial, including chemical spraying, mechanical harvesting, and non-native biocontrol species release (fish and insects). Hydrilla often has little effect on biodiversity (plants, fish, and birds). Anglers and hunters may oppose some aspects of Hydrilla management due to the positive effects of Hydrilla on recreational fishing and on local waterfowl abundance. In central Florida, management is adapted to promote a non-native apple snail that feeds on Hydrilla as a replacement prey for the imperiled Snail Kite Rostrhamus sociabilis. Is Hydrilla a weed or a wonder plant? Managers must confront this complexity with flexible, science-based approaches that account for often conflicting stakeholder viewpoints.
2:30PM Genetic Insights on Invasive Black Bass in Southern Africa
  John Hargrove
Black Bass (Micropterus spp) are global invaders with demonstrated negative impacts on native fish communities. Early in the 20th century, less than 100 Largemouth Bass (M. salmoides) were introduced into South Africa for the establishment of a recreational fishery. Subsequent translocations have expanded their distribution to include much of southern Africa. We review the use of genetic tools to track the spread of Micropterus species in the region, reconstruct their introduction history, and assess the consequences of repeated founding events on population success. We show that recent introductions of Florida Bass (M. floridanus) have expanded well beyond their initial point of introduction, despite legislation that prohibits fish movements between regions. Focusing in on select reservoirs, we show that populations of Largemouth Bass display very low levels of neutral genetic diversity despite evidence that multiple introductions were made into the country. Using DNA sequences from the native and introduced ranges of Largemouth Bass we identify Maryland as the most likely source for propagules used to seed South Africa. Together, these studies confirm that Black Bass can become established and persist across a wide range of environments despite limited levels of neutral genetic diversity.
2:50PM Refreshment Break
3:20PM Understanding Anglers Is Essential for Managing Invasive Alien Fishes in South Africa
  Olaf L. F. Weyl
Globally, the management of alien invasive fishes is complicated because many are important in fisheries but also harm recipient ecosystems. South Africa, where alien Rainbow Trout and Largemouth Bass are important in recreational fisheries, is no exception. The realization that the resultant fish invasions had considerable impacts on recipient ecosystems resulted in the cessation of government stocking programs and, efforts to remove alien fishes from conservation priority areas. Recognizing the economic benefits derived from alien fishes, management focus was on containing invasions by legislating areas for continued use. In response, trout anglers mounted strong opposition to proposed legislative and management interventions. This opposition, which included legal challenges have delayed the passing of alien invasive species legislation and frustrated river rehabilitation programs. In contrast, bass anglers have actively supported river rehabilitation initiatives and actively engaged with the legislative process, mainly requesting alterations to reduce impact on angling. Here, I provide insights on why the responses of trout and bass anglers were so different and, how active engagement by biologists might secure their future cooperation in the management of alien invasive fishes.
3:40PM The Outsized Role of Domestic Cats in the Transmission of Toxoplasma Gondii
  Grant Sizemore
Domestic cats (Felis catus) are among the world’s most harmful invasive species and a major contributor to dozens of species extinctions. In addition to functioning as an introduced predator, domestic cats also serve as an agent for the transmission of zoonotic diseases. Toxoplasmosis, caused by infection with the parasite Toxoplasma gondii, is one such disease with serious implications for human and wildlife health. The purpose of this talk is to review the epidemiological characteristics of T. gondii that make it an effective and dangerous parasite, including the outsized role of domestic cats in its transmission, and to identify policy and cultural shifts necessary to reduce T. gondii transmission risks. Wildlife managers and pet owners can help reduce risks through effective management, positive dialogue, and policies that keep cats safely contained.
4:00PM Trophic Ecology and Demographics of Flathead Catfish in the Lower Cape Fear River Ecosystem
  David Belkoski
The introduction of non-native catfishes has been identified as a major structuring force in central and southern US Atlantic coastal rivers. The flathead catfish (Pylodictis olivaris) is a large-bodied apex predator with established populations in several North Carolina coastal rivers. In 2017, we began an examination of flathead trophic ecology and population demography in the lower Cape Fear River ecosystem to assess potential impacts on anadromous and native fish communities. Over 1300 catfish have been sampled across broad size (65 – 1120 mm TL) and age (1 – 23 years) ranges. Stomach contents indicate a strong dependence on fish (49% FO and 77% W) and crustacean (58% FO). Stable isotope analyses indicate flathead as a top trophic predator with no significant differences among tributaries. The occurrence of freshwater prawn (Machrobrachium ohione) in the Cape Fear was unknown prior to this study and displayed high occurrence in the Black and Cape Fear. Common fish diet items include Ictalurids, Lepomis, Gobiidae, and Achiridae, indicating a preference for benthic prey. Flathead in the Cape Fear River show higher rates of omnivory than other Atlantic-slope introduced populations by preying heavily on crustaceans until shifting to strict piscivory around 800 mm.
4:20PM The Efficacy and Ecological Consequences of Using Triploidy for Aquatic Invasive Species Management
  Jenna Keeton
Established invasive species can negatively influence biodiversity and can catalyze environmental change. Traditional invasive species management often relies on strategies such as mechanical removal, chemical treatment, or biomanipulation to eradicate unwanted populations. However, these standard strategies rarely result in the eradication of invasive populations. One novel eradication technique is triploidy, where theoretically sterile conspecifics are stocked into aquatic ecosystems that have an invasive fish present to overrun diploid conspecific genes. The anticipated consequence of this strategy is full eradication of invasive fertile diploid populations, assuming triploid individuals mate with fertile conspecifics. However, fundamental physiological differences in cell structure may exist between ploidies, leading to potential variation in growth or behavior. The objective of this study is to understand population dynamics, growth and survival, and reproductive behavior of triploid walleye relative to diploids in Intermountain West reservoirs. We combine field sampling with underwater camera footage in experimental ponds to inform an age-structured model to determine population growth trajectories under various percent sterilities as well as initial population sizes. This modeling exercise will inform the overall viability of stocking triploid individuals as an invasive species mitigation effort with the potential to serve as the framework on which future triploidy studies are based.
4:40PM The Success of Injurious Wildlife Listing Under the Lacey Act
  Susan Jewell
For 119 years, the Lacey Act has prohibited harmful species, designated as injurious wildlife, from being imported into the United States. Since 1940, the U.S. Fish and Wildlife Service has had the regulatory authority for designating species as injurious. These are wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, and reptiles that may be invasive. Until now, the effectiveness of injurious listings by USFWS has been described only by non-Service entities who dwell on the apparent failures while ignoring the many preemptive successes. Here we evaluate the effectiveness of injurious listings with agency expertise. We quantify success by the effectiveness of listing relative to the stage of the invasion process: whether a species was established at the time of listing, and if not, if it is still established and if it subsequently spread to other States. Of nearly 300 species listed for invasiveness, only 6% were already established in the United States when listed, and all remain established. 94% were listed preemptively (not established when listed), and all remain not established. We conclude that prohibiting the importation of high-risk species by listing as injurious prior to their introduction and establishment in the United States is highly effective in preventing invasions.

Organizers: Kevin S. Irons, Nathan J. Lederman, Andrea Darracq
Supported by: Introduced Fish Section American Fisheries Society & Invasive Species Working Group The Wildlife Society

Location: Reno-Sparks CC Date: October 3, 2019 Time: 8:00 am - 5:00 pm