SGER: Impact of hydrogen sulfide toxicity on near shore community structure in the Pacific Northwest region

University Of Washington, Seattle WA

Investigators

Abstract

This research will examine a shift in community structure in shallow marine environments in the Pacific Northwest that is only now being recognized. Preliminary evidence suggests that Hydrogen Sulfide (H2S) poisoning may be threatening community structure in this region, through suppression of seagrass growth and germination as well as direct poisoning of marine invertebrates. The source of this H2S is from reduced organic matter deposited in shallow water sediments over the past several centuries. In the Pacific Northwest ancient, primarily coniferous, forests were removed and replaced by cleared land and a second and third growth blend of broadleaf trees, conifers and shrubs. This deforestation and the continued deposition of leaves from broadleaf tree species and shrubs introduced enormous quantities of debris into coastal waters. A significant amount of this material remains in the sediments. This condition reduces oxygen but increases H2S, which at elevated levels can poison marine plants and animals. The research will test the effects of varying concentrations of H2S in sediment and water column environments on various plants and animals that are native to the Pacific Northwest. This research has broader impacts for management of marine and coastal environments throughout the Northern Hemisphere.