Citation:

Price, A., R. Turner, V. Pospelova, G. Chmura, M. Coffin, J. Latimer, AND N. Rabalais. Monitoring water quality in Northwest Atlantic coastal waters using dinoflagellate cysts. To be Presented at New England Estuarine Research Society (NEERS) Spring Meeting, Portsmouth, NH, April 26 - 28, 2018.

Impact/Purpose:

The presentation will provide important results on state and impact indicators of nutrient pollution effects on estuaries. Since nutrient pollution is a major source of water quality impairments in US waters, these indicators are useful to assess the nutrient status and impacts on estuaries.

Description:

Nutrient pollution is a major environmental problem in many coastal waters around the US. Determining the total input of nutrients to estuaries is a challenge. One method to evaluate nutrient input is through nutrient loading models. Another method relies upon using indicators as early warning signs of water quality degradation. Dinoflagellate cysts (the fossilizable life stage of planktonic dinoflagellates) are an advantageous indicator of water quality since they are well preserved in the sedimentary record and can be used to track changes in nutrient pollution both spatially and temporally. We analyzed surface sediments from >30 estuaries spanning from Prince Edward Island (Canada) to Delaware Bay, and in short sediment cores collected from the northern Gulf of Mexico “dead zone.” By covering an extensive geographic area, we encompassed four estuary types and incorporated estuaries ranging from low to highly impacted. In the spatial study we show that heterotrophic dinocysts correlate to nutrient loading, and that the relationship improves when the type of estuary is taken into account. In the Gulf of Mexico sediment cores, dinocysts reveal changes in eutrophication since the 1930s. We demonstrate that four species in particular can be used as indicators of nutrient pollution in the Gulf of Mexico “dead zone.”

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