Thesis
The effects of venting and decompression on mortality and sublethal effects in yellow tangs (Zebrasoma flavescens) caught for the west Hawaii aquarium trade
Washington State University
Master of Science (MS), Washington State University
2012
Handle:
https://hdl.handle.net/2376/101138
Abstract
Each year, over 45 countries export 30 million fish from coral reefs as part of the global marine ornamental aquarium trade. Most fish harvested in the United States are collected in West Hawaii, where aquarium fishers annually remove over 400,000 fish from coral reefs. Recent discussions surrounding this fishery have centered on managing fish collection methods to reduce this catch volume. We conducted the first comprehensive study on the effects of aquarium fish barotrauma prevention and mitigation practices. Clinical signs of barotrauma caused by a forced ascent from depth can be prevented with decompression, or mitigated with venting (puncturing the swim bladder to release expanded internal gas). We studied the effects of three decompression treatments (fast, intermediate, slow) coupled with, or without venting in a fully crossed orthogonal design on yellow tang (Zebrasoma flavescens) mortality and sublethal effects, as elucidated through histology and serum cortisol. In Z. flavescens, post-collection mortality of 6% occurred within 24 hours of capture in fish subjected to fast decompression with no venting. The most popular methods in the fishery, fast or intermediate decompression followed by venting, resulted in no mortality. Histopathology of the heart, liver, head kidney, swim bladder and surrounding tissues in fish sampled 0 and 21 days post-collection revealed no significant inflammation or other lesions in any treatment groups. Fast decompression resulted in significantly higher serum cortisol than slow decompression, and venting alone did not significantly affect cortisol. Future studies should examine the links in the supply chain following collection to determine if further handling and transport stressors affect survivorship and sublethal effects.
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Details
- Title
- The effects of venting and decompression on mortality and sublethal effects in yellow tangs (Zebrasoma flavescens) caught for the west Hawaii aquarium trade
- Creators
- Emily Munday
- Contributors
- Brian N. Tissot (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525105601842
- Language
- English
- Resource Type
- Thesis