Unanswered Forum Topics

The effects of neodymium-iron-boron permanent magnets on the behavior of the small spotted catshark (Scyliorhinus canicula) and the thornback skate (Raja clavata)

Submitted by Kate McClellan on

Neodymium-iron-boron (Nd2Fe14B) permanent magnets were used to test behavioral responses in spotted catsharks (Scyliorhinus canicula) and thornback skates (Raja clavata). Both species significantly avoided the Nd2Fe14B magnets more often in comparison to the control and procedural control and they fed significantly more from the control an procedural control in comparison to the magnets. The study also demonstrated a correlation between avoidance speed and distance with water temperature. 

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Circle hooks: developing better fishing practices in the artisanal longline fisheries of the Eastern Pacific Ocean

Submitted by Kate McClellan on

An analysis of the performance of circle hooks in comparison to J-style and tuna hooks on the hooking rates of target and non-target species, specifically sea turtles, in the artisanal surface longline fisheries of Ecuador, Panama, and Costa Rica was performed. The target fisheries were mahi-mahi and a combination of tunas, billfishes, and sharks (TBS). In the TBS fishery, tuna hooks were compared to 16/0 circle hooks from Ecuador and Panama and 18/0 circle hooks from Costa Rica.

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The effects of acoustic alarms on the behavior of harbor porpoises (Phocoena phocoena) in a floating pen

Submitted by Kate McClellan on

Two porpoises were subjected to 3 different underwater sounds (standard Dukane alarm, random Dukane alarm, and a "bird alarm") in a enclosed floating pen. Their behavior during a 15 min test period was compared to behavior during a baseline 15 min period before the test and a recovery period after the test. All alarms resulted in increases in both the distance of the animals' surfacings from the alarms and their respiration rates. The standard Dukane alarm and the bird alarm were more effective than the random alarm in inducing animals to swim away from the source. 

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