Event Title

The puzzle of declining benthic invertebrate communities – could high organic matter deposition have a role?

Streaming Media

Presentation Abstract

Decades of monitoring by the Dept. of Ecology has documented declines in Puget Sound benthic communities; however, the deterioration of benthic communities does not correspond well with changes in individual chemical contaminants measured or laboratory tests for sediment toxicity. The spatial distribution of benthic communities is partly defined by the physical and oceanographic habitat, including delivery of nutrient-rich particles to the sediment. New measurements of total organic carbon, total nitrogen, and particle size indicate that organic matter accumulates preferentially in terminal inlets. Carbon and nitrogen content increases with the fraction of fine sediments (silt plus clay), which also tends to be high in low-energy environments such as terminal inlets. Total carbon and nitrogen in surface sediments are strongly positively correlated, indicating that sediment nitrogen is primarily organic in origin and that the carbon and nitrogen supplies are controlled by similar processes. In an effort to understand the declines in benthic communities, this presentation will explore the spatial concordance between locations with high levels of organic matter in sediments and adversely affected benthic communities.

Session Title

Session 1.1B: The Environmental Toxicology and Chemistry of the Salish Sea Ecosystem

Conference Track

Contaminants, Plastics, Microplastics, Toxicology & Stormwater

Conference Name

Salish Sea Ecosystem Conference (2020 : Online)

Document Type

Event

SSEC Identifier

2020_abstractID_4419

Start Date

21-4-2020 10:30 AM

End Date

21-4-2020 12:00 PM

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Language

English

This document is currently not available here.

Share

COinS
 
Apr 21st, 10:30 AM Apr 21st, 12:00 PM

The puzzle of declining benthic invertebrate communities – could high organic matter deposition have a role?

Decades of monitoring by the Dept. of Ecology has documented declines in Puget Sound benthic communities; however, the deterioration of benthic communities does not correspond well with changes in individual chemical contaminants measured or laboratory tests for sediment toxicity. The spatial distribution of benthic communities is partly defined by the physical and oceanographic habitat, including delivery of nutrient-rich particles to the sediment. New measurements of total organic carbon, total nitrogen, and particle size indicate that organic matter accumulates preferentially in terminal inlets. Carbon and nitrogen content increases with the fraction of fine sediments (silt plus clay), which also tends to be high in low-energy environments such as terminal inlets. Total carbon and nitrogen in surface sediments are strongly positively correlated, indicating that sediment nitrogen is primarily organic in origin and that the carbon and nitrogen supplies are controlled by similar processes. In an effort to understand the declines in benthic communities, this presentation will explore the spatial concordance between locations with high levels of organic matter in sediments and adversely affected benthic communities.