Presentation Abstract

Real-time and near-continuous in-situ measurements can provide new insights into variability and patterns of a marine system that would otherwise be undetected by sampling at a lower temporal resolution. King County has a comprehensive long-term marine water quality monitoring program in the Central Basin of Puget Sound that currently includes: bi-monthly water column vertical profiles, discrete sampling, near-surface real-time moored sensors, and new quantitative phytoplankton and zooplankton components. These data can assist with identifying changes and linkages in biogeochemical and ecological processes as well as changes in climate patterns. Recently, new moored and profiling optical nitrate sensors were added to existing monitoring systems to better understand nutrient dynamics. The mooring provides data at 15-minute intervals and the profiling sensor provides data throughout the water column at multiple sites. Nitrate data from 2016-17 are explored and tied to diurnal and seasonal patterns in physical conditions and phytoplankton dynamics. Our data show that variations in nitrate are tightly coupled to in-situ chlorophyll observations. During the phytoplankton growing season, near-surface nitrate may vary up to one order of magnitude in a short time period, such as from 0.03 to 0.32 mg/L in a day. Interannual differences are largely influenced by changes in river flow and oceanic inputs, weather, and climate. These data are framed in historical context of the long-term status and trends in nutrients from discrete sampling over the past two decades. By increasing our understanding of changes and drivers in nutrient patterns, these types of data records can help to inform models and management decisions, and better apply effective remediation targets for Puget Sound marine water quality.

Session Title

Interdisciplinary Approaches to Understanding Eutrophication and Over-enrichment of Nutrients in Puget Sound and Effects on Marine Species

Keywords

estuarine biogeochemical processes, nutrient dynamics, nitrogen, in situ continuous moorings

Conference Track

SSE16: Long-Term Monitoring of Salish Sea Ecosystems

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE16-82

Start Date

6-4-2018 9:00 AM

End Date

6-4-2018 9:15 AM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 6th, 9:00 AM Apr 6th, 9:15 AM

Nutrient dynamics and ties to environmental conditions and drivers in central Puget Sound

Real-time and near-continuous in-situ measurements can provide new insights into variability and patterns of a marine system that would otherwise be undetected by sampling at a lower temporal resolution. King County has a comprehensive long-term marine water quality monitoring program in the Central Basin of Puget Sound that currently includes: bi-monthly water column vertical profiles, discrete sampling, near-surface real-time moored sensors, and new quantitative phytoplankton and zooplankton components. These data can assist with identifying changes and linkages in biogeochemical and ecological processes as well as changes in climate patterns. Recently, new moored and profiling optical nitrate sensors were added to existing monitoring systems to better understand nutrient dynamics. The mooring provides data at 15-minute intervals and the profiling sensor provides data throughout the water column at multiple sites. Nitrate data from 2016-17 are explored and tied to diurnal and seasonal patterns in physical conditions and phytoplankton dynamics. Our data show that variations in nitrate are tightly coupled to in-situ chlorophyll observations. During the phytoplankton growing season, near-surface nitrate may vary up to one order of magnitude in a short time period, such as from 0.03 to 0.32 mg/L in a day. Interannual differences are largely influenced by changes in river flow and oceanic inputs, weather, and climate. These data are framed in historical context of the long-term status and trends in nutrients from discrete sampling over the past two decades. By increasing our understanding of changes and drivers in nutrient patterns, these types of data records can help to inform models and management decisions, and better apply effective remediation targets for Puget Sound marine water quality.