Maine Inshore Trawl


Fish and invertebrate abundance and size data collected by shrimp net for in and near shore areas of the New Hampshire and Maine coast. Data are available at OBIS. The OBIS compiled data includes species name, individual count, lat/lon, and some environmental correlates like depth and salinity. 

Dataset Location: OBIS Maine Inshore Trawl; Maine Department of Marine Resources Annual Data Summaries

Direct Download: OBIS Maine Inshore Trawl

Site Location: New Hampshire and Maine Coast

Site(s) Georeferenced: Yes

Timespan: 2000 - 2009

Sampling Frequency: biannual; first week May and first week October

Data Collection Summary / Methods: Stations are chosen for a stratified random design of 115 stations, 20 of which are fixed stations sampled each survey. The sampled areas are divided into 20 strata with four depth strata and five longitudinal regions based on oceanographic, geologic and biological features. Each strata includes once fixed station. The total survey area is approximately 4,617 square nautical miles with 1 station for every 40 NM2.

A modified shrimp net is used to sample for a variety of near-bottom dwelling species without targeting any specific component. It has a 2-inch mesh, with a 1-inch mesh liner in the cod end. A sonar system continuously monitors net dimensions during towing to assess consistency, maintain quality control, and provide swept area for biomass calculations.

For detailed methods - Year 1 Report

Data collected: Fish and invertebrate species ID, weight length. Some species include sex, maturity, age. Oceanography.

OBIS data schema: species name, individual count, date, location, temperature, depth, salinity, nitrogen, oxygen, silicate.

Known Issues: Ichtyoplankton (fish eggs and larvae) collection ended in 2004.

Best Practices: tips for separating the wheat from the chaff
Conditions for use: 'freely available' and 'open-access' as per OBIS:

From OBIS metadata - "Prior to use of these records in any analysis or report, David A. Libby must be notified and if used the provenance of the original data must be acknowledged. Acknowledge the use of specific records from contributing Maine Department of Marine Resources databases and acknowledge the use of the OBIS-USA facility. Recognize the limitations of data in OBIS-USA."

Citation/ Distributing Authors: David A. Libby. Maine Department of Marine Resources Inshore Trawl Survey, 2000 – 2009. 2010. Maine Department of Marine Resources, PO Box 8, West Boothbay Harbor, Maine 04575.  

Supplemental resources:

Maine - New Hampshire Inshore Trawl -

Maine Department of Marine Resources -

 Available via the EcoData Retriever: No


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