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2001 Progress Report: Impacts of Nutrients on Reefs in the Florida Keys
EPA Grant Number: R828020C005Subproject: this is subproject number 005 , established and managed by the Center Director under grant R828020
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: National Center for Caribbean Coral Reef Research (NCORE)
Center Director: McManus, John W.
Title: Impacts of Nutrients on Reefs in the Florida Keys
Investigators: Swart, Peter K.
Institution: University of Miami
EPA Project Officer: Perovich, Gina
Project Period: December 15, 1999 through December 14, 2003
Project Period Covered by this Report: December 15, 2000 through December 14, 2001
RFA: National Center for Caribbean Coral Reef Research (1999)
Research Category: Targeted Research , Congressionally Mandated Center
Description:
Objective:The project undertaken by the stable isotope laboratory is designed to evaluate the sources of nitrogen to the coastal reefs of South Florida using the stable isotopes of nitrogen (15N and 14N) as a tracer. In order to accomplish this task analyses were performed on the following components from the Florida offshore ecosystem off Key Largo i) algal samples, ii) samples of fish, iii) samples of particulate organic material, and iv) sample of inorganic nitrogen in the water column. Progress Summary:
This work commenced with a sampling cruise in June 2000 during which samples were taken for nitrate analysis. Additional samples for nitrate were taken during cruises made in August, October, and December 2000 as well as February 2001. Initial samples were collected to test and develop a method of extracting nitrate from the waters for nitrogen isotopic analysis. At the present time we do not feel that the isotopic analyses of the nitrate which we have made are of sufficient quality to report. However, we have identified the problem as being related to the extremely low nitrate concentration in these waters and have with the latest sampling adapted a method to increase the amount of water sample processed by an order of magnitude. This involves the collection of 4 liters of surface waters (rather than the 400 cm3 which was original used) and concentrating the water down to a volume of 400 cm3. During the last sampling we concentrated on obtaining more samples from deeper water depths which have higher concentrations of nitrate. In addition to the nitrate samples we have analyzed the nitrogen and carbon isotopic composition of the particulate organic material (POM) from all of the samples collected during our cruises. A summary of these data are included in figure 1. In addition samples of algae and fish muscle have been analyzed from the study area.
The analyses are planned to continue for a further 12 to 16 months. During this period we will:
- Produce a valid set of N isotopic measurements for ambient nitrate in the Florida Keys.
- Investigate the input of nitrogen from precipitation and to this end have started collecting rainfall from Miami and from the Florida Keys. These samples will be analyzed for the nitrogen isotopic composition of nitrate and ammonia. In addition we will attempt to analyze the isotopic composition of dry particulate material inthe atmosphere which has and is currently being collected by the atmospheric deposition group in Miami.
- Continue the analysis of the isotopic composition of marine algae and invertebrates.
- Investigate the changes in the nitrogen isotopic composition during the assimilation by fish.
No journal articles submitted with this report: View all 2 publications for this subproject
Supplemental Keywords:Coral Reefs, Estuarine Research, coastal ecosystem, aquatic ecosystem, watersheds, nutrient flux, Florida Keys, marine environment, nitrogen. , Ecosystem Protection/Environmental Exposure & Risk, Water, Geographic Area, Scientific Discipline, RFA, Water & Watershed, estuarine research, Ecology, Aquatic Ecosystems & Estuarine Research, Nutrients, Ecological Risk Assessment, algal blooms, Aquatic Ecosystem, Watersheds, Ecology and Ecosystems, State, coral reef communities, marine ecosystem, water quality, coastal resources, coastal watershed, watershed restoration, nutrient sensitive ecosystems, esturarine eutrophication, coral reef ecosystem integrity, ecological research, environmental indicators, Florida Keys, nutrient stress, coastal ecosystems, marine biology, wetlands, FLA, algal growth, bloom dynamics, ecological indicators, nutrient concentrations, estuarine integrity, aquatic ecosystems, coastal environments, coral reefs, environmental stress, coastal ecosystem, nutrient transport, nutrient cycling, watershed sustainablity, watershed sustainablility, estuaries, Florida, nutrient supply, ecosystem stress, ecosystem response, watershed assessment, nutrient flux
Progress and Final Reports:
Original Abstract
Main Center Abstract and Reports:
R828020 National Center for Caribbean Coral Reef Research (NCORE)
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828020C002 Nutrient Cycling and Algal Productivity in the Florida Keys
R828020C003 Top-Down Trophodynamics
R828020C004 Physical Oceanographic Studies
R828020C005 Impacts of Nutrients on Reefs in the Florida Keys