BROOKHAVEN NATIONAL LABORATORY --
DEPARTMENT OF APPLIED SCIENCES
Update: 981226-------------
Note:
This map shows the layout of the buoys and meteorological stations that are currently operated on the east end of Long Island by Brookhaven National Laboratory .
BROWN TIDES IN PECONIC BAY
In the mid to late 1980's "brown tides," algal blooms of a small species (Aureococcus anophagefferens), decimated the Peconic Estuary's scallop population and affected other living resources on Long Island's East End. The brown tide organism was simultaneously found in Narragansett Bay, Peconic Bay and Barnagat Bay in the summer of 1985. The blooms persisted in Peconic Bay for extended periods in 1985, 1986, 1987 and 1989, but blooms were not reported in Narragansett and Barnagat Bays. In 1986, Suffolk County began a modest brown tide monitoring and research program that continues today. The level of research targeted specifically to brown tide declined in 1988 when the blooms disappeared. In 1989, moored fluorometers developed at BNL were deployed in Peconic and Flanders Bays to monitor algal biomass.
The one-year study was a collaborative effort between BNL and Suffolk County, and its purpose was to collect time series of algal abundance that could be used to test numerical models that were being constructed to forecast brown tides. BNL continued the measurements into summer 1990. The occurrence of the brown tide in 1995 sparked renewed public and scientific interest. In response, Suffolk County, New York Sea Grant and BNL formed a partnership to provide new resources to determine the factors that control the growth of the brown tide organism.
BNL scientists and representatives from Suffolk County Department of Health Services met on January 10, 1996 and developed a collaborative research plan. The scientists and managers divided the effort into three components requiring approximately equal resources: laboratory studies to investigate the ecology of the brown tide organism, the installation of a brown tide monitoring network in Peconic Bay, and a retrospective analysis of historical data.
Analysis of historical data revealed that inorganic nitrogen carried to the bays by groundwater in a wet year feeds the growth of non-brown tide algae. Over the subsequent year, it is converted to organic nitrogen through the decay of plants and algae. If there is relatively little inorganic nitrogen delivered during that second year, the imbalance of nitrogen supply may create ideal conditions for a brown tide. The researchers also suggest that population growth and fertilizer use on land may amplify the effect, by increasing the inorganic nitrogen levels in the bays during wet years.
LONG ISLAND MESONET
Brookhaven National Laboratory began the Long Island Mesonet in 1994 as an extension of its meteorological observing activities. It was felt that off-site weather stations would provide important additional information in the event of an accident. A station at Smith Point on the south shore and, later, one at Orient
Point were established. A direct radio link was developed so that measurements could be collected instantly. The UHF (410.8 MHz) radio frequency transmissions were "line of sight," which works well on the relatively flat Long Island topography. Usually a data packet can be telemetered to the laboratory through only two or three repeaters in a couple of seconds. Once collected in the BNL "base station," the data are written to a real-time data file, processed for quality assurance, and are accessible on a world-wide web page immediately. Naturally, the web presentation continuously improves as we add graphical routines and analyses. The Smith Point and Orient Point meteorological stations have become popular over the years with fishermen, sailers, and vacationers.
The Peconic moorings have been designed to transmit their data into the Long Island Mesonet. As the sketch to the right shows, a sub-surface mooring is anchored so the sensors are as close to the surface as possible without being vuknerable to local boat traffic. The buoy measures the concentration of chlorophyll-a, which is related to the phytoplankton biomass, the temperature, the salinity, and the concentration of dissolved oxygen.
An antenna has been fitted into a simple float and connects to a radio in the buoy electronics package. The antenna is small and rugged so it will stand up to most weather and to minor boat collisions. In the event that the antenna is lost, the mooring will continue to collect data and store it in its memory for at least four months. It is a relatively simple job to recover the mooring, download the data, and install a new antenna.
contact: reynolds@bnl.gov