Macro and micro plastics in an urbanized and non-urbanized fjord estuary in the Northeast Pacific Ocean

Senior thesis written for Oceanography 445

[author abstract] Plastics, synthetic polymers which are durable and long lasting, have been appearing as marine debris for many decades. Macro-plastics (larger than 5 mm) and their effects on marine life have been well studied, documenting effects such as strangulation and digestive blockage in animals. Micro-plastics (0.3 mm to 5 mm in size), a result of either plastic produced in small pieces or fragmentation, have only recently begun being researched. This study characterizes macro and micro plastics in two NE Pacific estuaries, Puget Sound, WA and Nootka Sound, Canada. Macro-plastic concentrations were zero at all stations in both estuaries. Average micro-plastic concentrations at the surface ranged from 0 pieces/m3 to 102 pieces/m3, 5 m depth concentrations were 0 pieces/m3 to 44 pieces/m3 and 10 m depth concentrations were 0 pieces/m3 to 5300 pieces/m3. Fibers of plastic, assumed to be primarily marine in origin, had a higher concentration at most stations than those in pellet form, assumed to be terrestrial in origin. Understanding plastics’ distribution, origins, and effects on estuaries will require significant spatial and temporal sampling, beginning at the source.

University of Washington School of Oceanography