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Getting hooked: a study to better understand sea turtle longline by catch

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Date Issued:
2014
Abstract/Description:
Loggerhead and leatherback sea turtles are often caught as longline bycatch in fisheries worldwide. These species of sea turtle differ greatly in life history, morphology, and the ways they are hooked. Leatherbacks tend to be “foul hooked,” externally in the shoulder or flippers, while loggerheads tend to be hooked in the mouth or they swallow the bait so that hooking is internal esophagus or stomach. The numbers of loggerheads and leatherbacks caught decreased after changes in gear, bait and time of sets. However the proportion of leatherback mouth hookings increased while foul hooking decreased. We described and compared prey approach and attack behavior of both species in the presence and absence of visual targets. Waterborne squid and jellyfish odors were used to elicit feeding behavior in the two species. Visual targets were necessary to elicit biting. Loggerheads approach their prey with the mouth wide open, have exceptionally good aim and usually bite their intended target. This accuracy is consistent with the mouth and internal hooking. Leatherbacks frequently overshoot, miss their intended target then have to re-approach the target multiple times before making contact. Leatherback feeding behavior is disrupted easily if the body or flippers are touched during prey approach. This reapproach behavior may make leatherbacks more prone snagging on lines rigged with J-hooks. The shift by some fisheries to circle hooks, which are less prone to snagging, by give the leatherbacks multiple chances to attack the bait and ingest it without getting hooked externally.
Title: Getting hooked: a study to better understand sea turtle longline by catch.
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Name(s): Warraich, Natasha
Wyneken, Jeanette
Graduate College
Type of Resource: text
Genre: Abstract
Date Created: 2014
Date Issued: 2014
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 1 p.
Language(s): English
Abstract/Description: Loggerhead and leatherback sea turtles are often caught as longline bycatch in fisheries worldwide. These species of sea turtle differ greatly in life history, morphology, and the ways they are hooked. Leatherbacks tend to be “foul hooked,” externally in the shoulder or flippers, while loggerheads tend to be hooked in the mouth or they swallow the bait so that hooking is internal esophagus or stomach. The numbers of loggerheads and leatherbacks caught decreased after changes in gear, bait and time of sets. However the proportion of leatherback mouth hookings increased while foul hooking decreased. We described and compared prey approach and attack behavior of both species in the presence and absence of visual targets. Waterborne squid and jellyfish odors were used to elicit feeding behavior in the two species. Visual targets were necessary to elicit biting. Loggerheads approach their prey with the mouth wide open, have exceptionally good aim and usually bite their intended target. This accuracy is consistent with the mouth and internal hooking. Leatherbacks frequently overshoot, miss their intended target then have to re-approach the target multiple times before making contact. Leatherback feeding behavior is disrupted easily if the body or flippers are touched during prey approach. This reapproach behavior may make leatherbacks more prone snagging on lines rigged with J-hooks. The shift by some fisheries to circle hooks, which are less prone to snagging, by give the leatherbacks multiple chances to attack the bait and ingest it without getting hooked externally.
Identifier: FA00005861 (IID)
Collection: FAU Student Research Digital Collection
Note(s): The Fifth Annual Graduate Research Day was organized by Florida Atlantic University’s Graduate Student Association. Graduate students from FAU Colleges present abstracts of original research and posters in a competition for monetary prizes, awards, and recognition
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00005861
Use and Reproduction: Copyright © is held by the author with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.