Mitigating Impacts of Natural Hazards on Fishery Ecosystems

Poster Abstract: Hypoxia in Hood Canal: An Evaluation Using Before-After- Control-Impact Design

Caroline Paulsen and Tim Essington

doi: https://doi.org/10.47886/9781934874011.ch22

Poster Abstract.—Puget Sound, Washington, with more than 3,790 km of shoreline and a watershed of 42,800 km2, is the second largest estuary in the United States. Although Puget Sound supports a wide variety of marine species and economic industries, its health is deteriorating due to ecological stresses caused by fishing, climate change, habitat loss, water pollution, and excess nutrient input.

Increasing frequency of hypoxia, often occurring towards the end of summer, is of special concern in Hood Canal, a narrow 60-mi-long fjord located on the western side of Puget Sound basin. Hypoxia can lead to major fish and shellfish kills, negatively impacting both the local ecosystem and economy. Marine community composition and abundance is likely to be affected by late summer hypoxia, but this has yet to be fully evaluated.

The primary goal of this study is to evaluate the acute effects of hypoxia on the abundance and distribution of marine organisms at both the species-level and the community- level. Following the Before-After Control-Impact design, data will be collected at two sites in Hood Canal and two sites in the main Puget Sound basin through a twopart bottom trawling research cruise in summer 2007. Using these data, communities will be assessed both before and during the low dissolved oxygen (DO) that is typical in southern Hood Canal towards the end of summer. Impact assessment will be conducted by evaluating how similarities between paired sites diverge during the low DO period in late summer.