Weather Challenges, 14 Stations to Go

The Gulf of Maine (GOM) bottom longline survey is ongoing even though we have been dealing with challenges presented by the unfavorable weather conditions. Both vessels have completed four trips each and have collectively sampled 31 stations in the western and central Gulf of Maine.

white hake being measured

White hake being measured. Photo credit: NOAA Fisheries/Dave McElroy.

Catches have been very heavy in the central GOM consisting mainly of spiny dogfish, thorny skates, white hake, Atlantic cod, haddock, cusk, as well as some red hake and goosefish. Staff have been busy collecting otoliths, or earbones,  for ageing and sex and maturity data from larger sized Atlantic cod, haddock, white hake and cusk. This data supplements other NEFSC survey data.

white hake

White hake caught on the F/V Mary Elizabeth. Photo credit: NOAA Fisheries/Calvin Alexander

Thorny skates are also tagged as part of our collaborative work with Dr. Jeff Kneebone of the Anderson Cabot Center for Ocean Life at the New England Aquarium, and genetic samples were collected for genetics work being done at the University of Florida, led by Dr. Gavin Naylor. Dr. Gavin’s project is conducting a comprehensive analysis of thorny skate genetics across the species range in the Atlantic. They hope to better understand gene flow in the species, potential substructure in the population across their range, and the historical demography among regions.

GoPro camera in cage

GoPro camera in cage for bottom type verification. Photo credit: NOAA Fisheries/Calvin Alexander

A newly designed prototype for horizontal viewing of the bottom was tested on F/V Mary Elizabeth. It is hoped that this design would be more stable and improve the quality and consistency of bottom videos.

sunset

Gulf of Maine sunrise with the moon just above the horizon at center. Photo credit: NOAA Fisheries/Giovanni Gianesin

There are 14 stations left in the eastern Gulf of Maine, located at the outermost edge of our Exclusive Economic Zone (EEZ). If the weather cooperates we anticipate two more trips would be sufficient to complete the survey.

Calvin Alexander
Northeast Cooperative Research Program

Cooperative Gulf of Maine Fall Bottom Longline Survey Underway

Note: This is the start of the fifth year of the cooperative Gulf of Maine bottom longline survey, conducted with two commercial longline fishing vessels and staff from the Northeast Fisheries Science Center’s Cooperative Research Program. 

The 50-foot F/V Mary Elizabeth and 40-foot F/V Tenacious II departed over the weekend of October 13-14 to begin the first leg of the Gulf of Maine bottom longline survey.  F/V Mary Elizabeth departed from Situate, Massachusetts on Oct. 13 with Brian Gervelis and Dominique St. Amand onboard, while F/V Tenacious II departed Sesuit Harbor in Dennis, Massachusetts on Oct. 14 with Dave McElroy and Christopher Sarro onboard. These two small fixed-gear vessels provide a great platform and expertise for completing this type of survey in the Gulf of Maine. The survey deploys tub-trawl longlines pre-baited with squid, similar to how vessels of this type fish commercially.

squid-baited-hooks-longline-gear

Squid baited hooks of bottom longline gear. Photo credit: NOAA Fisheries/Dave McElroy

Collectively both vessels sampled 10 stations in the western Gulf of Maine; nine stations were rough bottom and the other a smooth bottom. The survey focuses effort on complex hard bottom by substratifying the survey strata into rough and smooth bottom type using a depth based algorithm and the NOAA chart data. One of the primary objectives is to collect supplementary data in these hard bottom habitats to complement the other NEFSC surveys in these areas. The catches in the first trip were dominated by spiny dogfish with some Atlantic cod, haddock, red hake, cusk, four species of skates, one small Atlantic halibut, and one Atlantic wolffish.

highrisers-on-stern

F/V Mary Elizabeth with high risers for the bottom longline gear. Photo credit: NOAA Fisheries/Dominique St. Amand

The survey also collects temperature and depth data, and a current instrument is deployed on each end of the gear to measure the current velocity and direction over the gear during deployment.

longline-gear-deployed

Bottom longline being deployed on F/V Tenacious II. Current meter (bottom right) is tethered to both ends of the gear. Photo credit: NOAA Fisheries/Dave McElroy

Both vessels returned to their respective ports late in the afternoon on Monday, Oct. 15, due to the onset of unfavorable weather. Once the weather breaks the crews will be headed out to complete stations in the central and eastern portions of the Gulf of Maine.

Dave McElroy
Cooperative Research Program