The Resource Assessment Project monitors the distribution, relative abundance, and size composition of marine species in state water with annual surveys. This includes coastwide spring and fall trawl surveys and a seine survey in southern Cape Cod. Survey data helps inform regional fish stock assessments.
Trawl survey
Resource conservation laws demand that the best scientific information be used as the basis for management actions. The Resource Assessment Project's mission is to collect and analyze data for this process. Massachusetts' coastal and estuarine species vary in quantity and diversity. The Resource Assessment Project conducts spring and fall surveys of state waters with an otter-trawl. The surveys coincide with seasons when either adults or juveniles are available inshore.
The aim of this project is to get fishery independent data on finfish, crustaceans, and mollusks. This data includes:
- Species distribution
- Quantity
- Size
- Age composition
The project staff prepares and presents this data to fishery managers. The managers use this data for creating policies governing the use and protection of fishery resources. Stock assessment analyses rely on other informational sources to estimate resource data. The main information comes from recreational and commercial fisheries.
Fishery-independent surveys operate differently from other types of fishing. Trawl surveys fish in a standardized manner over a wide area to give an unbiased population quantity index. Before conducting the actual survey, DMF does the following:
- Bases the survey on a stratified random design that uses 5 bio-geographic regions
- Divides each region into depth zones called strata
- Assigns 100 stations from each survey, based on approximate proportion of each stratum's area
- Select survey tow locations at random within each stratum
- Base selection on presence of "good" bottom and absence of fixed gear.
Most of the important fish species caught in state waters belong to stocks with wide geographic distributions. Thus project data adds to the stock assessments of the Atlantic Marine Fisheries Commission (ASMFC) and the National Marine Fisheries Service. ASMFC and regional management councils have used results for managing inter-jurisdictional fishery resources. Project personnel serve on many interstate scientific committees and working groups that study single and multi-species groupings. Some have also published peer reviewed scientific papers.
DMF emphasizes sampling the state's most important finfish resources. These include winter flounder, summer flounder, Atlantic cod, scup and black sea bass.
For the current survey you can:
Additional Resources
Seine survey
Each year, DMF biologists conduct a seine survey for young of the year (YOY) winter flounder. These fish are only an inch or two long at the time of the survey. Biologists take samples from these estuaries:
- Great Pond (Falmouth)
- Waquoit Bay (Falmouth, Mashpee)
- Cotuit 3 Bays (Barnstable)
- Lewis Bay (Barnstable, Yarmouth)
- Bass River (Dennis, Yarmouth)
- Stage Harbor (Chatham)
The aim of the survey is to provide a relative abundance index of winter flounder juveniles for population modeling of the Southern New England Winter Flounder Stock Unit. Surveys begin after June 15 and usually takes 9 days. Biologists favor morning tides when beaches are less busy.
What is a beach seine?
A beach seine is a net suspended vertically in the water column. There are weights on the bottom half and floats on the top half to create a wall from the seafloor to the surface. Researchers hold opposite ends of the net and walk it onto the shore. The net has a slight bowl to it to keep fish from swimming out the sides. Winter flounder tend to swim towards shore and perpendicular to the weighted footrope. This makes them easier to catch. Typically, biologists release all the caught animals back into the water alive after they identify and count each one.