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Jessica Walden

I recently obtained my Master of Science in Oceanography and Marine Environments, and will be beginning the PhD program at UC Irvine Fall 2018. I love the ocean! Everyone seems to know that the rainforest is important for the production of oxygen, but fewer know that the ocean actually supplies over HALF of the earth’s oxygen! Tiny plant-like organisms called phytoplankton float in the water all over the world and perform photosynthesis just like plants on land—they are also the base of the food chain. These microalgae are extremely diverse and respond to a changing environment in different ways; some are sensitive and thrive in particular niches, while others can live anywhere. My current project takes advantage of the collaboration between the Mackey Lab and the Orange County Sanitation District (OCSD). OCSD performs monthly monitoring of the coast between the Newport Pier and the Santa Ana River jetty, where their effluent outfall pipe discharges treated wastewater at 60m depth, about 5 miles offshore. They collect water and analyze it for ammonia and bacteria, while I analyze the water for nitrate, phosphate, chlorophyll, and phytoplankton community composition and abundances.


After a year and a half of research with OCSD looking at phytoplankton and biogeochemistry, I hope to add a microplastic component to my studies. I believe these variables are not mutually exclusive, as both microplastic particles and phytoplankton are carried with ocean currents and interact with chemical and biological elements. Plastic, in addition to carrying its own cocktail of harmful chemicals, acts as a sponge for attracting surrounding chemicals, like persistent organic pollutants (POPs). When plastic particulates are ingested by organisms, these chemicals desorb and are incorporated into tissues within the organisms. As larger organisms eat smaller organisms, the chemicals bioaccumulate and reach a higher concentration. As humans at the top of the food chain, the risk for ingesting carcinogenic and endocrine disrupting chemicals is high. The issue of plastic in the ocean is beyond an aesthetic desire for a pure and unadulterated landscape - it is a human health issue in need of more attention, research, and policy. to see how effective it is. My goal is to utilize the current relationships I have built, and to foster new ones, in order to combine biogeochemical and phytoplankton analyses with microplastic pollution studies in Orange County, CA.

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