Abstract

In Bermuda, invasive lionfish are concentrated in deeper waters (30 - 60 m) inaccessible to volunteer cullers, but are regularly caught as bycatch in commercial lobster traps at these depths. Bermuda does not allow ‘fish pots’, so the Department of Environ-mental Protection is working to modify standard lobster traps to increase lionfish catch and reduce the catch of spiny lobster, while maintaining low levels of finfish bycatch. Using insights from camera observations of commercial lobster traps, two iterations of trap designs and protocols were tested. Experimental traps were monitored using GoPro cameras with Cam-Do controller cards and deepwater ScoutPro housings. Modifications tested included: shading the traps; varying the funnel type (including various wire funnel designs, and side- and top-mounted plastic funnels); and varying baiting practices (including use of decoy baits). Shading the traps increased lobster catch while decreasing lionfish catch. Use of dead bait increased bycatch of all types significantly but, for a given trap design, lionfish catch was similar across baiting strategies. In the low-relief habitat at 60 m, the structure of the trap alone appears sufficient to attract lionfish. The presence of escape gaps reduced finfish bycatch significantly, while lionfish were retained. Lionfish “hot spots” were an important influence on catch rates. Optimal set time was 10 - 14 days. Traps with wire funnels terminating in a black 7” ring are being tested further alongside the deepwater commercial lobster fishery. With lobster bycatch reduced, a lionfish trap fishery could potentially operate during the summer closed season, but may not be cost-effective in isolation.

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