Publisher :
Place of publication :
Publication year : 2008
Thematic : Fisheries
Language : English
Note
Sea turtles are injured and sometimes killed because of interactions with pelagic longlines,
such as hook ingestion, entanglement in the lines, and forced submergence. Stimuli from bait,
gear and lights (often used at night on swordfish lines) might attract sea turtles. Previous experiments
with loggerheads Caretta caretta demonstrated that the turtles were attracted to the lights, but no
comparable studies have been done with other species. Our goal in this study was to determine
whether juvenile leatherbacks Dermochelys coriacea, reared in the laboratory for 5 to 42 d postemergence,
responded to the lights in the same way as loggerheads. Each leatherback was presented
once in varying order with 3 different colored light stimuli from either chemical lightsticks (n =
16 turtles) or battery powered LEDs (n = 16 turtles) commonly used in the fishery. Most leatherbacks,
in contrast to loggerheads, either failed to orient or oriented at an angle away from the lights. These
results imply that the capture of leatherbacks on longlines might occur for other reasons (by accident,
through attraction to bait odor or to concentrations of natural prey located near the lines). Alternatively,
older turtles might show responses that differ from those of juvenile turtles. We review previous
studies based upon logbook data and conclude that because of confounding factors, there is no
convincing evidence that marine turtles are attracted to the longlines by lights. We recommend that
better-designed field experiments be carried out to determine whether fishery lights have an effect
on marine turtle capture rates.
Go to source
Keywords : Sphenomorphus diwata
Encoded by : Pauline Carmel Joy Eje
