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|Herring Research: Spawning Surveys|
One focus of Atlantic herring research in the Gulf of Maine is to document when and where herring spawn. The first researcher to conduct underwater studies of herring egg mats in the Gulf of Maine was Richard Cooper of the University of Connecticut's Marine Science Center. From 1973 to 1977, he used a team of divers to locate herring spawning beds on Jeffreys Ledge.
Dr. Cooper and his colleagues employed otter trawls, bottom grabs, and a remotely-controlled photo sled to locate spawning sites on Jeffreys Ledge and described the time and location of each spawning event based on larval surveys. A key project goal was to identify the factors, such as predation and oxygen limitation, that cause mortality of herring eggs and larvae. 
Recently, the Island Institute of Maine and researcher David Stevenson (formerly of the Maine Department of Marine Resources) conducted a project to study the timing and location of herring spawning from Vinalhaven to West Quoddy Head, Maine. The project, titled the Eastern Gulf of Maine Atlantic Herring Spawning Area Survey, began in 1997. This project was a follow-up to egg and larval surveys conducted in eastern Maine by Dr. Stevenson during the 1980's with plankton nets, a remotely-operated underwater vehicle equipped with a video camera, SCUBA divers, and a bottom grab sampler. The objective was to see if the abundance of herring spawning in eastern Maine had declined since the 1980's. [2, 3]
The Island Institute project locates herring spawning beds in downeast Maine and Grand Manan coastal waters, records the location of the egg mat and water depth, and maps the site using a global positioning system (GPS). The size and depth of each herring spawning site, as well as the substrate to which the eggs are attached, are determined by sampling the bottom using a benthic collecting device.
Egg bed surveys conducted in eastern Maine in the 1980's and 1990's relied heavily on information from a network of local lobster and herring fishermen who find herring eggs attached to their lobster traps and fishing gear during the spawning season. The reporting network established by the Island Institute extended approximately 240 km from the Monhegan Island area into eastern Canada and offshore to Grand Manan Island.
On Grand Manan and Monhegan Islands, where lobster fishing is prohibited during the herring-spawning season, custom-built egg collectors were deployed around the island where lobster traps would normally be placed. They consisted of a piece of plastic-coated wire mesh weighed down by two bricks. They were the same size as the bottom of a lobster trap and were buoyed and tended by local residents.
Field survey results from the project, combined with fishermen interviews, led to several conclusions. First, data collected during the Island Institute study indicate that spawning activity has declined compared to the 1980s - Eight spawning sites were found in eastern Maine during 1997-1999, averaging three per year, compared to eight per year between 1983 and 1988. These results are supported by local fishermen who reported that herring spawning in eastern Maine has declined in recent years. Secondly, there appear to be fewer adult and juvenile herring in certain areas, especially along inland waters of the Maine coast. Finally, spawning events in recent years have occurred later during the fall season and in lower numbers and intensity, although the location of the spawning sites has not changed. [3, 4, 5]
 Cooper, R. A. (11/2000) Personal Communication. University of Connecticut, Avery Point Marine Lab.
 Island Institute Programs, Herring Spawning Area Survey Website. http://atlas.islandinstitute.org/ii/programs.asp?section=marineresources&subsection=5.
 Stevenson, D. K. (1989) Spawning locations and times for Atlantic herring on the Maine coast. Maine Department of Marine Resources Res. Ref. Doc. 89:5.
 Neal, B. (2001) Eastern Gulf of Maine Atlantic Herring Spawning Area Survey Project Year 4 Summary. Island Institute. Rockland, Maine.
 Neal, B. (2003) Eastern Gulf of Maine Atlantic Herring Spawning Area Survey Project Year 6 Summary. Island Institute. Rockland, Maine.