Improving the Bottom Trawl Survey for the Northeast
Here’s how the Northeast Fisheries Science Center is contributing to the Northeast Trawl Advisory Panel and connecting the panel’s advice to our science mission.
Our fisheries research surveys are crucial to understanding the overall status of commercially and recreationally important fishery stocks. They also help us understand how these stocks change over time.
At the Northeast Fisheries Science Center we value the expertise of industry and other stakeholders. We look for ways to collaborate with others to make our science better.
This is why we are active members of the Northeast Trawl Advisory Panel (NTAP), an industry advisory panel set up by the New England and Mid-Atlantic Fishery Management Councils. The panel includes fishery management council members, commercial trawl fishermen, academic and industry gear experts, leaders of other regional surveys, state scientists, and the Center staff assigned to work with this important panel.
NTAP Fact Sheet (PDF, 2 pages)
Northeast Trawl Advisory Panel Goals
- Understand NOAA/NEFSC trawl survey gear performance and methodology
- Evaluate ways to complement or supplement regional research surveys
- Improve understanding and acceptance of NOAA/NEFSC trawl survey data quality and results
To work effectively with the Northeast Trawl Advisory Panel, our science center has formed an internal team. Team members come from our survey, stock assessment, and cooperative research branches, as well as our center's leadership team.
Restrictor Rope Research
This research is intended to quantify how a restrictor rope affects the composition, rate, and size distribution of catch derived from a bottom trawl survey. A restrictor rope is used by some in the commercial fishing industry to physically control the door spread in a bottom trawl, but it has yet to be used on scientific survey vessels in the region. At-sea experiments for this research were completed in 2022, and final results of the study are expected in 2023.
Trawl Door Testing
The trawl doors currently used during the NEFSC bottom-trawl survey have variable wingspread performance in shoal (shallower) waters. “Wingspread” is how widely the net opens when it is operating. The goal of this work is to find a trawl door that achieves a target net spread of 13 meters and provides consistent wingspread performance over the range of depths sampled during the survey.
Learn more about trawl door testing research
2019 Wingspread Research
Consistently fishing a trawl survey net is essential to creating a consistent data time series. Optimal width is 13 meters, but it can vary with depth, which affects net efficiency. Net efficiency is a measure of how effectively a net captures animals in its path. This study investigated how differences in wingspread at different depths might influence our index time series.
Learn more about wingspread research
2019 Flume Tank Demonstration
The primary objective of this effort was to observe the 1:7 scale model of the standard NEFSC survey bottom trawl in the flume tank and evaluate physical changes to the model as net spread changed.
Learn more about flume tank demonstration
Rockhopper Catch Efficiency Study
The goal of this research was to estimate the relative catch efficiency of rockhopper and chainsweep trawl gears for the NEFSC bottom trawl survey, with a focus on flatfish species.
Learn more about this sweep efficiency research