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Full-Text Articles in Life 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 …


The Distribution And Demography Of The Invasive Pacific Oyster, Crassostrea Gigas, And Native Olympia Oyster, Ostrea Lurida, In The San Diego River, Jason Langevin Oct 2019

The Distribution And Demography Of The Invasive Pacific Oyster, Crassostrea Gigas, And Native Olympia Oyster, Ostrea Lurida, In The San Diego River, Jason Langevin

Theses

Even though the introduction of the Pacific Oyster, Crassostrea gigas, to the west coast of North America, happened roughly a century ago, it has only been in the past 15 to 20 years that C. gigas has started to become an established and conspicuous species along Southern California’s coast. The establishment of C. gigas in Southern California has the potential to heavily influence many native species, as it has done globally. In Southern California, this invasion is particularly relevant for the native Olympia Oyster, Ostrea lurida. The Olympia oyster has both historical and present-day threats to its population, …


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 …