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Animal Sciences Commons

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Full-Text Articles in Animal Sciences

The Effects Of Seasonal Variations, El Niño-Southern Oscillation, And Climate Change On The Tuna-Dolphin Association, Caitlynn Birch, Michael D. Scott, Zhi-Yong Yin, Lisa T. Ballance Nov 2019

The Effects Of Seasonal Variations, El Niño-Southern Oscillation, And Climate Change On The Tuna-Dolphin Association, Caitlynn Birch, Michael D. Scott, Zhi-Yong Yin, Lisa T. Ballance

Theses

Tuna and dolphins swim together in the waters of the eastern tropical Pacific, and this association has long benefitted tuna fishermen and intrigued scientists. Although the tuna-dolphin association is often referred to as a “mystery,” much is known about the association. Yellowfin tuna are primarily caught with spotted dolphins and, to a lesser extent, spinner dolphins; historically the spotted dolphin has borne the brunt of the bycatch mortality. The tuna-dolphin association is thought to be a product of the distinct oceanography of the ETP: a shallow mixed layer, a thick oxygen minimum zone, and warm surface waters. As the mixed …


Spatial And Temporal Variation In The Diet Composition Of Zooplankton In Mission Bay, Bryanna Paulson Aug 2019

Spatial And Temporal Variation In The Diet Composition Of Zooplankton In Mission Bay, Bryanna Paulson

Theses

Analyses of quantitative data on zooplankton diets are vital for understanding the drivers of zooplankton abundance within an ecosystem. Such analyses also provide insight into trophic pathways within the lower planktonic food web, which support populations of higher trophic level species. This study used carbon and nitrogen stable isotope ratios of size-fractionated plankton in Mission Bay, San Diego, CA to examine the spatial and temporal variation in zooplankton trophic ecology and determine potential environmental drivers of zooplankton community structure. Carbon stable isotopes reflect primary production sources in an organism’s diet, and nitrogen stable isotope ratios can be used to estimate …