Maine Lobstermen Investigate Alternative Gear Technologies

By Emily Patrick and Kevin Staples

DMR Division of Marine Mammal Research

Before Congress paused new federal whale rules in 2022, Maine lobstermen faced significant restrictions under proposed changes to the Atlantic Large Whale Take Reduction Plan (ALWTRP) to meet the National Marine Fisheries Service’s (NMFS) risk reduction target. At that time, options for reducing risk through gear modifications were limited, and most were expensive and untested by Maine fishermen.

With funding from NOAA Sea Grant’s American Lobster Initiative (ALI), the Maine Department of Marine Resources (DMR) partnered with industry associations, Stony Brook University (SBU), and individual Maine fishermen to test alternative endline systems and compare their operational feasibility and gear-location accuracy with traditional line and surface buoys.

Rather than testing fully ropeless systems, the research evaluated lower-cost, lower-tech gear retrieval and locating technologies with input from Maine fishermen. The goal was not only to conduct field trials, but also to answer the practical questions that matter on the water: What works? What doesn’t? How are fishing operations impacted? And how much risk reduction could these alternative tools provide?

Findings

The research found that the release devices themselves generally performed well, but challenges remained with storing and deploying the stowed gear. The alternative systems also took longer to haul than traditional gear. For alternative surface marking, acoustic positioning systems produced the most accurate estimates of gear location, but individual readings varied considerably.

These findings highlight the importance of evaluating not only whether alternative gear technologies function as intended, but also whether they are practical, reliable, and efficient under real fishing conditions.

Gear Retrieval Systems Testing: Spring and Timer Releases

Sixteen commercial fishermen volunteered to test two retrieval systems — a tagline spring release that uses ‘whale-safe’ weak rope to trigger a spring mechanism that allows stronger stowed rope to be hauled for retrieval, and an electronic timer release that allows fishermen to program the release of stowed rope at a desired time interval. Testers were compensated for training and integrating each system into two separate hybrid fishing trawls, with one experimental and one traditional end, and recording data on their trawl configuration and hauling activity.

Fishermen collected data from 1,137 spring release and 598 timer release experimental hauls from October 2023 through March 2026. The testing fleet represented almost all Maine lobster management zones (no volunteers from Zone C), contained a mix of federally permitted and state-only license holders, and operated vessels from 35 to 50 feet long. Most testing occurred in nearshore and intermediate waters, with depths ranging from 25 to 600 feet (4 to 100 fathoms) and trawl lengths from pairs to 20-trap trawls (Figure 1).

Figure 1. The number of experimental hauls for spring and electronic timer releases within 10 nautical mile grid cells across Lobster Management Zones A through G (Lobster Management Area 1) in the Gulf of Maine.

So, did the gear work? The ability to get the gear onboard does not tell the whole story — it is important to also understand the frequency of issues and why it did or didn’t work. Fishermen-reported issues occurred for 22% of spring release hauls (while only 11% were unsuccessful) and 27% of timer hauls (while only 23% were unsuccessful). When we break down the data to understand where the problems occurred, the release devices were rarely the problem: spring releases were 98% problem-free, and timed releases 97%. Problems with the line containment system and buoy visibility during gear retrieval occurred during 6-11% of project hauls. Fishermen reported that the line containment system, a net bag floating above the bottom, was prone to getting tangled, which ultimately prevented the stowed rope from reaching the surface for hauling. Fishermen also reported that the trawl buoy used for retrieval was susceptible to being pulled under the surface by strong tides and currents causing buoy visibility issues. These observations underscore how the performance of a release device can be undercut by other equally critical retrieval system components.

Getting gear back onto the boat is only one part of successful fishing. There’s also the time it takes to haul through gear. Hauling both the spring and timer release experimental systems were slower than average estimates to haul traditional gear. The median time participants spent hauling and preparing their gear for redeployment was 7 minutes for the spring release systems and 8 minutes for the timer systems, with the slowest taking 35 minutes (Table 1).

Fishing these alternative endline systems generally takes longer because they require additional steps, such as packing line and resetting devices. In addition to being time-consuming, these systems also introduce more points of potential failure or delays. Time is money, so it is important for fishermen to understand the full scope of operational challenges as well as added costs associated with this gear.

Do These Release Systems Reduce Risk?

The decision to fish an alternative gear must consider its conservation benefit to whales. The spring release systems use a tagline that has a breaking strength of less than 1700 lbs. This increases the conservation benefit to whales by making the entire endline fully weak, rather than having weak links at intervals in an otherwise stronger line. The conservation benefit increases as gear is fished in deeper waters.

The timer release system risk reduction was more variable, influenced by individual fishermen setting the time delay to gear release for each soak and the impact of weather-related hauling delays on anticipated retrieval times. These systems removed lines from the water for more than 40% of the soak time across all months during testing, with a peak of over 94% in August (Table 2).

Timer release systems provide significant reductions in endline presence but lack traditional surface marking. This adds to the complexity of deploying timer releases when compared to spring release systems, since they require alternatives to surface marking methods to identify where the subsurface gear is located.

Locating Gear on Bottom Without a Surface Buoy

Maine fishermen know where their gear is by a glimpse of a buoy at the surface. If those buoys are removed, how will fishermen, other vessels, and enforcement know that gear is on bottom? DMR tested two digital gear marking options on the accuracy of identifying the location of gear on bottom when surface buoys are not present: surface GPS marks on a multi-function display (MFD/plotter) and marking through acoustic localization using messages transmitted via sound from vessels to gear. DMR evaluated the accuracy of each method in locating deployed gear relative to surface buoys during 12 experimental field days aboard two commercial fishing vessels and the DMR research vessel R/V Maine.

During research surveys, fishermen deployed 2 acoustic tags attached to anchors with GPS-tagged buoys on traditional endlines (Figure 2). Anchors were deployed at target locations to represent various gear densities. Fishermen plotted GPS marks as gear was set and navigated their vessels at different distances and directions to simulate approaches within fixed gear areas. While the acoustic technology recorded data, DMR staff tracked start & end times, gear deployments, and environmental conditions.

DMR tested two ultra-short baseline (USBL) acoustic positioning systems from different manufacturers (System 1 and System 2). System 1 was evaluated in 34 trials at an average depth of 161 feet, while System 2 was evaluated in 17 trials at an average depth of 127 feet. Acoustic positions were recorded individually and combined over time to calculate a more accurate position through triangulation, a method used in some positioning system displays.

The combined acoustic positioning systems produced the most accurate estimates of gear location, followed by gear positions recorded by vessel operators at deployment and the traditional buoy positions. Although combined acoustic positions were the most accurate, individual readings varied considerably. DMR staff observed estimated gear locations jumping around the chart during trials, making it difficult to determine the most reliable position in real time for both System 1 & 2 (Figure 3). Some systems display positions with greater confidence and clarity than others. For fishermen, knowing how reliable a position estimate is can be just as important as its accuracy. System 2’s combined acoustic positions were more accurate relative to the modeled actual seafloor location than those of System 1, though with fewer trials and in shallower waters (Figure 3).

Strong currents and extreme tides in the Gulf of Maine can cause gear to shift during deployment and between hauls, reducing the accuracy of recorded surface positions. Wind, tides, currents, and the amount of line deployed also affect the location of surface buoys relative to gear on the seafloor.

The fishermen who participated in this research played a critical role in evaluating the practicality of currently available alternative endline gear and methods to mark gear on bottom without a surface buoy. Maine fishermen understand the challenges of fishing in Maine waters and their firsthand experience provides valuable insight beyond the technical performance of these systems. Their participation helped identify not only gear performance and risk reduction, but also the operational challenges, necessary adaptations, and changes to fishing practices that are critical considerations in assessing the potential use of these gears.

For more information on DMR’s Gear Research Program and alternative gear testing please visit https://www.maine.gov/dmr/science/right-whale/gear.