Vital Study of Lobster Gear Begins This Month

The Department of Marine Resources (DMR) study of vertical lines used in the lobster fishery kicks off in full this month. The three-year project, funded by a $714,000 grant from the National Marine Fisheries Service (NMFS) Section 6 Species Recovery program, will study the strength of rope used by lobstermen in Maine, New Hampshire, Massachusetts, Rhode Island and Connecticut.
Erin Summers is the lead investigator for DMR. “The project’s primary goals are to document what types of rope fishermen use in their vertical lines and how those lines are rigged, to determine the functional breaking strength of existing vertical lines, and to document the hauling loads fishermen experience by installing load cells aboard fishing vessels,” Summers said.
To do this, Summers and her colleagues will be breaking used rope donated by lobstermen — lots of rope. Summers secured the loan of a huge machine used by NMFS to test rope strength in the past at the agency’s gear shed in Rhode Island, where rope and gear removed from entangled whales are kept. “They put the machine in storage some years ago and no one knew how to operate it,” Summers said. “We brought a trailer down and took it to the Boothbay Harbor lab. We just turned it on last week and it started right up.”
The rope testing machine is a 3,000-pound monolith with a relatively simple mechanism. Rope to be tested is secured to two pins — one above, one below. A motor then engages to pull the pins apart at a designated speed. The rope stretches and ultimately breaks. The pounds of pressure required to break the rope is recorded on a computer console within the machine.
As part of the project, Summers will collect rope that has been fished by lobstermen throughout the region to compare to the breaking strength of new rope. Donated rope can be from inshore or offshore, knotted or spliced together. The point is to test the actual rope used by lobstermen in different areas and in different conditions. For instance, splices decrease rope strength by 25%; knots reduce the strength of the rope even more. Understanding the real breaking strength of existing rope will provide an important baseline of data for use by resource managers.
The project also will place small, stainless steel load cells on lobster boats throughout the summer. These machines are small, wired devices shaped like a blunt letter “S.” “It eyebolts to the top and bottom of the davit block,” Summers said. “Then as the line is hauled in it pulls apart inside, recording the pounds of pressure exerted on the line.” The load cell records pressure every 1.5 seconds, giving researchers a continuous, fine-scale data series.
The load cells have been tested with Maine lobstermen since last September. Currently two lobstermen are using them on their boats. “So far it’s been trial and error because lobster boats and hauling systems all differ a bit. We have people to help lobstermen troubleshoot installation and how to operate the load cell. We are asking lobstermen to use it for one week, to fish through their gear,” Summers said. Summers estimates that she will have between 15 and 20 load cells to place on boats this summer.
DMR also is building an online survey form to gather information on lobstermen’s surface systems and the type of rope and rigging used in their vertical lines. The survey will include questions about the zone and distance from shore the traps are set, depth fished, vessel size and size of hauler, type and diameter of ropes used, use of knots and splices, and number of traps on a trawl, among other things. “It will be set up so that you can fill it out online or you can ask for a paper copy, or call in your information,” Summers said. There will be a phone number that lobstermen can call with questions or to ask for help. The data will be sent to FB Environmental Associates, an environmental services firm in Portland which is a co-investigator in the project. FB Environmental will be responsible for data collection and database management as well as outreach for the project’s duration.
Yong Chen at the University of Maine will incorporate the data into a computer model that shows the relationship between the breaking strength of vertical lines and the conditions and environmental factors at play, such as location and season. The model will provide information on the benefits that proposed management actions might offer.
Gathering the project’s multiple sources of data on vertical lines together this summer is of great importance because in October the Large Whale Take Reduction Team will meet to discuss additional regulations to protect North Atlantic right whales. At that meeting, members of the team will discuss techniques to reduce the potential for right whales to become entangled in lobster gear. The two techniques the team is investigating right now are the use of sections of rope spliced into vertical lines that will break at 1,700 pounds of pressure and the use of ropeless trap technology in the lobster fishery.
“We will do a preliminary data pull in September and October, prior to the meeting. We will be collecting data after that throughout the project and will continually update the information,” Summers said.