NOAA 2004-R417
Contact: Theresa Eisenman
NOAA News Releases 2004
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New research using monitoring data from the National Oceanic and Atmospheric Administration’s (NOAA) National Estuarine Research Reserves examines metabolic rates as indicators of the health of estuaries. This is the largest and most geographically diverse study of its kind and is the first time a study on metabolic rates has been initiated in the shallow, near shore regions of the estuarine reserves, coastal areas where rivers meet the seas. The study will be published in the upcoming edition of Estuaries. NOAA is an agency of the U.S. Department of Commerce.

Conducted by scientist Jane Caffrey, Ph.D., the University of West Florida, the research provides an analysis of metabolic rates using identical measurements from the reserves. This research provides a baseline within specific U.S. estuaries that coastal managers can potentially use to evaluate changes in water quality and the reason for those changes.

“Ecosystem metabolism can be used as an indicator of an estuary’s health similar to using the human pulse rate to measure our own body’s health,” states Caffrey. “Ecosystem metabolism provides an index for the estuary’s health in three ways; the magnitude of production or consumption in the ecosystem, the seasonal changes in production and consumption, and the difference between production and consumption, which is called net ecosystem metabolism.”

The most significant result of this study is that the type of habitat adjacent to the monitoring site explains the general trends in net ecosystem metabolism. Marsh and mangrove creeks typically consume organic material. While submerged aquatic vegetation, such as eelgrass, usually produce organic material. Caffrey found that freshwater sites tend to consume more organic material than saltier areas. Larger systems tend to be more balanced. Smaller systems tend to be more consuming.

Most metabolic research focuses on larger, deeper systems. This study examines specific estuarine sites on a national basis. Caffrey studied 42 sites within 22 of NOAA’s 26 National Estuarine Research Reserves using data collected through the System-wide Monitoring Program (SWMP, pronounced swamp). SWMP provides reliable, continuous data at frequent intervals. Each estuarine reserve collects SWMP data using identical protocols, and each reserve represents a different type of estuarine system in the United States.

“SWMP measures many water quality variables. The key variable that I use for determining metabolic rate is dissolved oxygen,” states Caffrey. “If we go back to the human body analogy, measuring dissolved oxygen is like examining how the estuary is breathing.”

The National Estuarine Research Reserve System is a federal-state partnership program. This network of twenty-six protected areas provides long-term research, monitoring, education and coastal stewardship.

NOAA's National Ocean Service is dedicated to exploring, understanding, conserving and restoring the nation’s coasts and oceans. It balances environmental protection with economic prosperity in fulfilling its mission of promoting safe navigation, supporting coastal communities, sustaining coastal habitats and mitigating coastal hazards.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation’s coastal and marine resources.

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