Quartermaster Harbor (QMH) is a 3,000 acre shallow embayment between Vashon and Maury Islands in Puget Sound, Washinton. QMH consists of a relatively shallow inner bay (5.5 m avg) connected by a channel to a deep outer bay (11 - 46 m avg) (DeGasperi and Ferguson 2012). Judd Creek which is the largest freshwater source to QMH, enters the inner harbor at the northwestern corner near Burton. The outer harbor experiences relatively high flushing rates through tidal currents; whereas, the waters of the inner harbor are less affected by the tides and have lower flushing rates (DeGasperi 2010). In 1916, an artificial isthmus was built by the Army Corps of Engineers to connect Vashon and Maury Islands. Before construction of the isthmus, water was able to enter the bay from the Main Basin during high tide (DNR 2004). The reopening of the channel has been considered for improvement of water and habitat quality in QMH (DeGasperi 2010).
QMH is an essential spawning and rearing habitat for several fish and shellfish including endangered salmon and forage fish such as herring. In addition, it is a National Audubon Society Important Bird Area since many marine birds winter in QMH (DeGasperi 2010). The habitat diversity found in QMH led the Washington State Department of Natural Resources (DNR) to create Maury Island Aquatic Reserve (MIAR) (DNR c2012). The MIAR consists of 5,530 acres of sub- and inter-tidal areas which include eelgrass beds and herring spawning grounds (DNR c2012).
QMH experiences low dissolved oxygen (DO) events in the late summer and autumn, presumably caused by algal blooms and the subsequent bacterial respiration associated with phytoplankton decomposition (DeGasperi and Ferguson 2012). The DO concentrations in QMH fall below the Washington State Water Quality Standards which may lead to uninhabitable conditions for marine organisms. QMH has been targeted by the U.S. Environmental Protection Agency (EPA) and King County as a research area of interest with a focus on anthropogenic sources of nitrogen inputs which contribute to hypoxic conditions (DeGasperi and Ferguson 2012). The Quartermaster Harbor Nitrogen Management Study aims to identify the sources and quantify the levels of nitrogen loading into the harbor (KING c2012).