Evaluation of fishing gears modified to reduce ecological impacts in commercial fisheries
To sustainably and responsibly harvest commercial aquatic species in the world’s fisheries, consideration must be given towards the negative physical and biological effects that fishing gears place on marine ecosystems. Fish habitat degradation, bycatch of undersized and non-target species, carbon f...
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| Format: | Thesis |
| Language: | English |
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Memorial University of Newfoundland
2014
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| Online Access: | https://research.library.mun.ca/6408/ https://research.library.mun.ca/6408/1/Murphy_Andrew_John_032014_MSc.pdf https://research.library.mun.ca/6408/3/Murphy_Andrew_John_032014_MSc.pdf |
| Summary: | To sustainably and responsibly harvest commercial aquatic species in the world’s fisheries, consideration must be given towards the negative physical and biological effects that fishing gears place on marine ecosystems. Fish habitat degradation, bycatch of undersized and non-target species, carbon footprint, reductions in biodiversity and biomass are just some of the negative impacts of fishing gears. One novel method to reduce impacts while maintaining commercially viable catch rates of target species is through modification of fishing gears. Two experimental studies, conducted for this thesis, evaluated the catch characteristics of innovative, modified fishing gears designed to mitigate ecological concerns specific to each study’s respective fishery. In the first study, the Newfoundland cod pot was modified in an attempt to target flatfish species while avoiding the capture of snow crab (Chionoecetes opilio). Major findings include the importance of artificial light and entrance shape in capturing American plaice (Hippoglossoides platessoides). Also, non-baited pots that contained only artificial light were successful in capturing plaice while greatly reducing the capture of snow crab. In the second study, at-sea catch characteristics of northern shrimp (Pandalus borealis) and non-targeted bycatch species were compared between two trawls, one containing a traditional rockhopper ground gear currently used in the northern shrimp fishery, the other containing an experimental ground gear designed to reduce seabed contact. Catch rates and size of shrimp were found to be comparable between trawls however the experimental trawl captured significantly more bycatch. |
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