Gulf of Maine Cooperative Bottom Longline Survey Database

Metadata Updated: November 18, 2018

This database is for a bottom longline (fixed gear) survey executed in the western and central Gulf of Maine targeting complex rocky habitats. The survey is operated from collaborating commercial fishing vessels, and deploys 1 nm sets of traditional 'tub trawl' bottom longline groundfish gear (1000 hooks). Longline gear is deployed at randomly selected stations within selected NEFSC bottom trawl survey (BTS) strata in the western and central Gulf of Maine during the spring and autumn, overlapping temporally with the NEFSC seasonal BTS in that region. Specific ‘hard’ and ‘smooth’ bottom sub-strata were chosen within the BTS strata based on predictive habitat maps that have identified complex habitat at a spatial resolution of @1.3km2 (Manderson et al. 2011). The total number of longline stations are allocated by the overall area of each stratum, as done in the NEFSC BTS, and stations randomly distributed in the ‘hard’ and ‘smooth’ sub-stratum within each stratum. Each set is made for 2 hours, with gear deployed 1 hour prior to the estimated time for slack tide at that location. The ambient current is monitored with an instrument with an accelerometer (also equipped with a compass and thermometer), which is attached to the mainline on each end of the longline (by the last hook). Temperature-depth probes are deployed on the anchor at each end of the longline. Catch weights, fish lengths, and other biological data are collected for all species following standard survey protocols. Biological sampling (for age and reproductive data) is collected for a subset of species and sizes relative to the BTS’s request protocols to fill in data on uncommon species, and less common sizes (i.e. larger individuals) of key groundfish.

The objective of this survey is to provide important information for several species that are not well sampled in BTS or those that are not caught in substantive numbers (targeted) by commercial or recreational fisheries to inform management, Endangered Species Act (ESA) listing decisions, and conservation plan measures. These include cusk, which is a candidate species under the ESA and a data poor stock, as well as Atlantic Wolffish, Atlantic Halibut, and Thorny Skate, which are all NOAA Species of Concern. This survey is designed to increase sampling opportunities for all of these species. Catch and biological data from this survey provides useful supplemental data and indices for other groundfish including white hake, barndoor skate, red hake, spiny dogfish, haddock, Atlantic cod, and smooth skate.

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Metadata Date January 25, 2018
Metadata Created Date March 28, 2016
Metadata Updated Date November 18, 2018
Reference Date(s) (publication)
Frequency Of Update continual

Metadata Source

Harvested from NOAA CSW Harvest Source

Additional Metadata

Resource Type Dataset
Metadata Date January 25, 2018
Metadata Created Date March 28, 2016
Metadata Updated Date November 18, 2018
Reference Date(s) (publication)
Responsible Party Northeast Fisheries Science Center (Point of Contact, Custodian)
Contact Email
Access Constraints Access Constraints: NEFSC Data Access Constraint: If data is stored on an internal NEFSC network, the requester may not have direct access to query the data unless they are also authorized for network access. | Use Constraints: Disclaimer - While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Bbox East Long -67.60223
Bbox North Lat 43.27977
Bbox South Lat 42.09656
Bbox West Long -70.5602
Coupled Resource
Frequency Of Update continual
Guid gov.noaa.nmfs.inport:27731
Harvest Object Id 6c003412-eab7-488d-8f39-58769a8e5707
Harvest Source Id 2aed8e29-fc5b-4cde-aa66-fb1118fd705e
Harvest Source Title NOAA CSW Harvest Source
Metadata Language eng
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 2014-04

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