ECOLOGY OF THE COPPER RIVER DELTA, ALASKA

The vast majority of our understanding of estuaries is based on studies of sub-tropical and temperate estuarine areas.  Few studies of subarctic and arctic estuaries have been conducted in coastal Alaska, despite the economic importance of the fisheries, wildlife and natural resources many of these systems provide.  At the Prince William Sound Science Center we have been conducting the first detailed study of the Copper River Delta estuary, the 640 km² estuary by Cordova.  We selected the Copper River Delta as our study site because the Delta’s ecological and economic resources are at risk to potential oil spills.  The Trans-Alaska oil pipeline crosses six major tributaries of the Copper River.  A breach of the pipeline at one of these sites, or a tanker spill in Prince William Sound or in the Gulf of Alaska would pose a severe threat to the ecology of the Copper River Delta.  

Our overall hypothesis is that the distribution, abundance and production of benthic invertebrates residing in intertidal sediments of the Copper River Delta are controlled by a combination of top-down and bottom-up (nutrient and primary production) processes To evaluate the central predictions of this hypothesis, we developed a comprehensive sampling program on the western Copper River Delta and in southeast Prince William Sound (Orca Inlet), an area adjacent to and influenced by the Copper River.  Since 2001 we have sampled the intertidal benthic invertebrate community at a series of permanent plots.  Beginning in 2002 we established a series of seven stations to sample the demersal fish and crab communities that inhabit the Delta’s intertidal and subtidal waters.  And since 2003 we have sampled key hydrographic parameters including the temperature, salinity, and turbidity at 11 estuarine stations.  We have also documented nutrient levels at the 11 stations as well as five major rivers and sloughs entering the estuary.