An analysis of suspected crayfish invasions in Missouri, U.S.A.: evidence for the prevalence of short-range translocations and support for expanded survey efforts

Abstract

Biological invasions are increasing in frequency and the need to mitigate or control their effects is a major challenge to natural resource managers. Failure to control invasive species has been attributed to inadequate policies, resources or scientific knowledge. Often, natural resource managers with limited funds are tasked with the development of an invasive species control program without access to key decision-support information such as whether or not an invasive species will cause damage, and what the extent of that damage may be. Once damages are realized, knowing where to allocate resources and target control efforts is not straightforward. Here we present the history of invasive species policy development and management in a large, multi-jurisdictional and multi-use aquatic ecosystem. We present a science-based decision-support tool for on-the-ground aquatic invasive species (AIS) control to support the development of a sustainable control program. Lastly, we provide a set of recommendations for managers desiring to make an AIS control implementation plan based upon our development of novel invasive species research, policy and management in Lake Tahoe (USA). We find that a sustainable invasive species control program is possible when science, coordination and outreach are integrated.

Environmental DNA detects a rare large river crayfish but with little relation to local abundance

“…Research to date has found F. eupunctus primarily associated with higher order streams, greater groundwater spring flow volumes and higher current velocity, thus making F. eupunctus a large river habitat specialist relative to sympatric congeneric crayfishes (Flinders & Magoulick, ; Magoulick et al., ; Nolen et al., ). Faxonius eupunctus is recognised as Threatened by the American Fisheries Society (Taylor et al., ) and Vulnerable by the International Union for Conservation of Nature (Richman et al., ), and it is currently being evaluated for federal protection under the United States Endangered Species Act (ESA), owed in part to its narrowly endemic range and risk for displacement by non‐native crayfishes (DiStefano, Imhoff, Swedberg, & Boersig, ; Imhoff, Moore, & DiStefano, ). Given the rarity and conservation need of this organism, eDNA may prove useful in better defining the distribution of F. eupunctus within the Eleven Point River drainage, including evaluating the species’ potential use of tributary streams.…”

Co-occurring lotic crayfishes exhibit variable long-term responses to extreme-flow events and temperature

“…Environmental variables, such as temperature and flow, can influence range expansion and competitive abilities of invading crayfishes, which may lead to the exclusion of na-tive species (Flynn and Hobbs 1984, Bubb et al 2004, Mazlum and Eversole 2005. For example, future populations of the narrowly endemic Spothand Crayfish could be affected by the introduced Virile Crayfish Faxonius virilis (Hagen, 1870), which has invaded at least 117 km of the Current River downstream of JFR study sites (DiStefano et al 2015, Rozansky 2019. Virile and Spothand crayfishes are ecologically (Pflieger 1996), morphologically (Rozansky 2019), and genetically (Crandall andFitzpatrick 1996, Taylor andKnouft 2006) similar.…”

Fisheries Volume 48 Number 5 May 2023

“…Biologists have documented crayfi sh invasions at more than 31 locations in Missouri, and statewide mail surveys of Missouri bait and pet stores in 2010 indicated that both industries could be prominent crayfi sh introduction pathways (DiStefano et al 2015(DiStefano et al , 2016. The Missouri Department of Conservation (MDC) implemented regulations in 2014 to reduce introductions by limiting sales of crayfi sh in bait and pet stores to one native species, the virile crayfi sh Faxonius virilis , and provided associated educational materials to all bait stores (DiStefano et al 2015(DiStefano et al , 2016. Despite MDC ' s focus on the bait industry, prior to the current study, the agency had not examined pet stores as pathways for potentially invasive crayfi sh or compliance with the 2014 regulation.…”