Improving the efficiency of the Fukui trap as a capture tool for the invasive European green crab (Carcinus maenas) in Newfoundland, Canada

Abstract

The European green crab (Carcinus maenas) is a crustacean species native to European and North African coastlines that has become one of the world’s most successful marine invasive species. Targeted fishing programs aimed at removing green crabs from invaded ecosystems commonly use Fukui multi-species marine traps. Improving the efficiency of these traps would improve the ability to respond to green crab invasions. In this study, we developed four distinct trap modifications that were designed to facilitate the successful capture of green crabs, with the goal of improving the performance of the Fukui trap. We tested these modifications in situ during the summer of 2016 at two locations in Placentia Bay, Newfoundland. We discovered that three of our modified Fukui trap designs caught significantly more green crabs than the standard Fukui trap, increasing catch-per-unit-effort (CPUE) by as much as 81%. We conclude that our top-performing modifications have great potential for widespread use with existing Fukui traps that are being used for green crab removal efforts.

The first management of a marine invader in Africa: The importance of trials prior to setting long-term management goals

“…In Canada, the most common baited trap design captured only 16% of C. maenas individuals that attempted to enter the trap (Bergshoeff et al, 2018). The CPUE was increased by 81% through simple design modifications (Bergshoeff et al, 2019). If a future attempt was made to eradicate the crabs from elsewhere, a mix of capture strategies would be recommended.…”

The Green Wave: reviewing the environmental impacts of the invasive European green crab (Carcinus maenas) and potential management approaches

“…or cod (Gadus spp.) and allowed to soak for 24 hours before recovery (Duncombe and Therriault 2017;Bergshoeff et al 2019;Mabin et al 2020;Poirier et al 2020). Fyke traps are nearly three times more efficient in capturing C. maenas than Fukui traps; however, Fyke traps also capture nearly ten times more bycatch than Fukui traps (Poirier et al 2020).…”

“…Fyke traps are nearly three times more efficient in capturing C. maenas than Fukui traps; however, Fyke traps also capture nearly ten times more bycatch than Fukui traps (Poirier et al 2020). Modifications have been proposed to improve the catch rate of C. maenas in Fukui and Fyke traps and should be implemented in trapping protocols if possible (Bergshoeff et al 2018(Bergshoeff et al , 2019Poirier et al 2018). The logical capitalization of an intensive trapping program -a C. maenas fishery -has been proposed as a management tool for reducing C. maenas in Atlantic Canada (St-Hilaire et al 2016).…”

Life History and Population Dynamics of Green Crabs (Carcinus maenas)

“…Underwater video used to evaluate the effectiveness of Fukui traps to catch green crabs revealed only a 16% success rate out of 1226 entry attempts [254]. It has been shown recently that certain modifications to the Fukui traps can significantly increase productivity up to 59% [255]. Passive nets are sometimes used but this method trusts to the currents and wandering crabs to enter the net so may be equally unreliable as a population density estimate.…”