Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2017 Animal movement is motivated in part by energetic constraints, where fitness is maximized by minimizing...

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Main Author: van der Hoop, Julie
Format: Thesis
Language:English
Published: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution 2017
Subjects:
Online Access:https://hdl.handle.net/1912/8468
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spelling ftwhoas:oai:darchive.mblwhoilibrary.org:1912/8468 2023-05-15T17:36:05+02:00 Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment van der Hoop, Julie 2017-02 https://hdl.handle.net/1912/8468 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/8468 doi:10.1575/1912/8468 doi:10.1575/1912/8468 Whales Dolphins Drag Thesis 2017 ftwhoas https://doi.org/10.1575/1912/8468 2022-05-28T22:59:45Z Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2017 Animal movement is motivated in part by energetic constraints, where fitness is maximized by minimizing energy consumption. The energetic cost of movement depends on the resistive forces acting on an animal; changes in this force balance can occur naturally or unnaturally. Fishing gear that entangles large whales adds drag, often altering energy balance to the point of terminal emaciation. An analog to this is drag from tags attached to cetaceans for research and monitoring. This thesis quantifies the effects of drag loading from these two scenarios on fine-scale movements, behaviors and energy consumption. I measured drag forces on fishing gear that entangled endangered North Atlantic right whales and combined these measurements with theoretical estimates of drag on whales’ bodies. Entanglement in fishing gear increased drag forces by up to 3 fold. Bio-logging tags deployed on two entangled right whales recorded changes in the diving and fine-scale movement patterns of these whales in response to relative changes in drag and buoyancy from fishing gear and through disentanglement: some swimming patterns were consistently modulated in response. Disentanglement significantly altered dive behavior, and can affect thrust production. Changes in the force balance and swimming behaviors have implications for the survival of chronically entangled whales. I developed two bioenergetics approaches to estimate that chronic, lethal entanglements cost approximately the same amount as the cost of pregnancy and supporting a calf to near-weaning. I then developed a method to estimate drag, energy burden and survival of an entangled whale at detection. This application is essential for disentanglement response and protected species management. Experiments with tagged bottlenose dolphins suggest similar responses to added drag: I ... Thesis North Atlantic Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Woods Hole, MA
institution Open Polar
collection Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server)
op_collection_id ftwhoas
language English
topic Whales
Dolphins
Drag
spellingShingle Whales
Dolphins
Drag
van der Hoop, Julie
Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
topic_facet Whales
Dolphins
Drag
description Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2017 Animal movement is motivated in part by energetic constraints, where fitness is maximized by minimizing energy consumption. The energetic cost of movement depends on the resistive forces acting on an animal; changes in this force balance can occur naturally or unnaturally. Fishing gear that entangles large whales adds drag, often altering energy balance to the point of terminal emaciation. An analog to this is drag from tags attached to cetaceans for research and monitoring. This thesis quantifies the effects of drag loading from these two scenarios on fine-scale movements, behaviors and energy consumption. I measured drag forces on fishing gear that entangled endangered North Atlantic right whales and combined these measurements with theoretical estimates of drag on whales’ bodies. Entanglement in fishing gear increased drag forces by up to 3 fold. Bio-logging tags deployed on two entangled right whales recorded changes in the diving and fine-scale movement patterns of these whales in response to relative changes in drag and buoyancy from fishing gear and through disentanglement: some swimming patterns were consistently modulated in response. Disentanglement significantly altered dive behavior, and can affect thrust production. Changes in the force balance and swimming behaviors have implications for the survival of chronically entangled whales. I developed two bioenergetics approaches to estimate that chronic, lethal entanglements cost approximately the same amount as the cost of pregnancy and supporting a calf to near-weaning. I then developed a method to estimate drag, energy burden and survival of an entangled whale at detection. This application is essential for disentanglement response and protected species management. Experiments with tagged bottlenose dolphins suggest similar responses to added drag: I ...
format Thesis
author van der Hoop, Julie
author_facet van der Hoop, Julie
author_sort van der Hoop, Julie
title Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
title_short Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
title_full Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
title_fullStr Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
title_full_unstemmed Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
title_sort effects of added drag on cetaceans : fishing gear entanglement and external tag attachment
publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
publishDate 2017
url https://hdl.handle.net/1912/8468
genre North Atlantic
genre_facet North Atlantic
op_source doi:10.1575/1912/8468
op_relation WHOI Theses
https://hdl.handle.net/1912/8468
doi:10.1575/1912/8468
op_doi https://doi.org/10.1575/1912/8468
op_publisher_place Woods Hole, MA
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