Managing non-native fish in the environment

Abstract

Non‐native fishes are frequently used to enhance aquaculture and fisheries; if introduced into the wider environment, then the majority will have negligible effects on native biodiversity. However, a minority will become invasive, causing adverse ecological effects, and so management actions may be needed to minimize their dispersal and impacts. These actions include eradication attempts from specific waters or well‐defined spatial areas, population control by suppression (e.g. through removal programmes) and containment of existing populations to prevent their further spread. These remedial actions have generally only been undertaken across large spatial areas in developed countries; experience suggests a fundamental constraint is a lack of selective removal methods that target the non‐native fish species only. For example, eradication methods tend to be limited to low technology, ‘scorched‐earth’ techniques (e.g. biocide chemicals) whose use is generally constrained to relatively small and enclosed water bodies. Risk management of non‐native fishes should ensure that actions taken are commensurate with the level of risk posed by that species in the environment; although pre‐introduction risk assessment schemes have been developed, there remains a lack of decision support tools for post‐introduction situations. Although this inhibits the management of non‐native fishes in the environment, control programmes such as those against common carp Cyprinus carpio in Australia and topmouth gudgeon Pseudorasbora parva in England and Wales suggest there is potential for invasions to be managed and controlled within large spatial areas, even if their eradication may not be feasible.

Age, growth and population dynamics of two congeneric and invasive gobies, Rhinogobius giurinus and R. cliffordpopei (Actinopterygii, Gobiidae) in a plateau lake, southwestern China

“…R. cliffordpopei spawned from February to June with the main spawning activity from March to April, and R. giurinus spawned from April to August with the main spawning activity from May to June , which matched the spawning seasons of the two species. These biological traits and the differences between the two species are crucial for defining the mesh size of benthic fyke nets that could be used for physical removals, timing of deployment of control actions and control methods in different seasons (Ling, 2002;Britton et al, 2011). First, to remove small-sized individuals, the mesh size of benthic fyke nets should be smaller than 4 mm from March to June for R. cliffordpopei and from June to August for R. giurinus.…”

“…Fish are among the most widely introduced animals in fresh waters and the overall number of introduced species is more than 624 species, with a rate of introduction that has doubled in the last 30 years (Gozlan et al, 2010). Invasive fish can have significant ecological and evolutionary impacts on the colonized habitats (Cucherousset & Olden, 2011) and management actions have been implemented to mitigate these impacts (Britton et al, 2011). Simberloff (2003) argued that the detailed study of population biology of introduced species is very likely to fine-tune the current management protocols, and may also facilitate the establishment of new control methods.…”

“…Therefore, determining population biology and quantifying life-history traits (e.g. age, growth, survival, reproduction and population dynamics) of invasive fish are the crucial prerequisite for cost-effective management (Ludgate & Closs, 2003;Britton et al, 2011;Houston et al, 2014).…”

Responses of Aquatic Non-Native Species to Novel Predator Cues and Increased Mortality

“…While other studies have summarized efforts to eradicate or remove invasive aquatic animals (Meronek et al 1996, Rayner & Creese 2006, Locke et al 2009, Freeman et al 2010, Halfyard 2010, Kolar et al 2010, Britton et al 2011, Gherardi et al 2011, Nico & Walsh 2011, mine is the first to examine removal efforts through the lens of compensation. I aimed to examine the relationship between compensation and removal success across a diverse assortment of locations and removal strategies.…”

“…This literature search was performed using the following key words: aquatic, pest, management, removal, eradication, species. Citations in topical review papers and books were also examined (Meronek et al 1996, Veitch & Clout 2002, Halfyard 2010, Kolar et al 2010, Britton et al 2011, Loppnow et al 2013, Ojaveer et al 2015. I also performed a secondary literature search to look for evidence of density-dependent recruitment for each species that was a target of removal in the case studies.…”