April 22, 2019 — The following was published by NOAA Fisheries:
On April 23, a group of approximately 60 fishermen, scientists, conservationists, and state and federal officials will come together to discuss ways to further reduce serious injury and mortality of endangered North Atlantic right whales caused by trap/pot fishing gear. The group will meet in Providence, Rhode Island for four days. At the end of the meeting, they hope to agree on a suite of measures that will reduce right whale serious injuries and deaths in fishing gear in U.S. waters from Maine to Florida to less than one whale per year, the level prescribed by the Marine Mammal Protection Act.
“Tackling entanglements is critical to the recovery of the North Atlantic right whale population, and we can’t do it without the assistance and cooperation of those who know best how the fishing industry interacts with large whales,” says Mike Pentony, regional administrator for NOAA Fisheries Greater Atlantic Region. “The continued participation and dedication of our industry, science, NGO, and agency partners is absolutely necessary to future success.”
About Right Whales
These whales, which got their name from being the “right” whales to hunt because they floated when they were killed, have never recovered to pre-whaling numbers. Due in part to conservation measures put in place to protect these whales from incidental entanglements in fishing gear and vessel strikes, we saw steady population growth from about 270 right whales in 1990 to about 480 in 2010. But in 2010, another downward trajectory began. This downward trend, exacerbated by an unprecedented 17 mortalities (particularly in the Gulf of St. Lawrence snow crab fishery) in 2017, brought a new urgency to modify the existing Atlantic Large Whale Take Reduction Plan.
That Plan, developed by the team of stakeholders meeting next week, identifies a number of conservation measures from area closures to gear modifications that U.S. fixed gear fishermen have already implemented. Despite these efforts, today the population is estimated to be fewer than 411 whales. Only twelve births have been observed in the three calving seasons since the winter of 2016/2017, less than one third the previous average annual birth rate for right whales. This accelerates the trend that began around 2010, with deaths outpacing births in this population.
Take Reduction Planning
The Marine Mammal Protection Act requires that if serious injuries and mortalities to a population of marine mammals due to U.S. commercial fisheries is above a level that the stock can sustain, NOAA Fisheries convene Take Reduction Team to develop consensus recommendations on how to reduce this threat.
The immediate goal of a Take Reduction Team is to develop a to reduce incidental mortality and serious injury to a level, known as the “potential biological removal” level, that allows the stock to stabilize or grow, rather than decline. Although it’s been in existence since 1997, the Atlantic Large Whale Take Reduction Plan has not been able to consistently reduce serious injuries and mortalities to below the potential biological removal level.
Cost of Entanglement
Entanglements are currently the leading cause of known right whale mortality. More than 80 percent of right whales carry scars that indicate that they have been entangled in fishing lines, and nearly 60 percent of those are entangled more than once. Not all entanglements drown whales. Some prevent a whale from feeding, increase the energy a whale needs to swim and feed and cause pain and stress to the animal, which weakens it. Biologists believe that the additional stress of entanglement is one of the reasons that females are calving less often; females used to have calves every 3-5 years, and now are having calves every 6-10 years.
In recent years, most documented fishing gear entanglements of large whales (like right and humpback whales) that result in serious injury and mortality come from trap/pot gear. The traps lie on the ocean floor and are connected to buoys at the surface by long vertical buoy lines.
Many whales that are entangled are discovered after the event, with no gear attached. In some instances, gear is retrieved, analyzed, and stored for future analysis; much of this retrieved rope is consistent with buoy lines. That said, 71 percent of all recovered/observed gear (2009-2018) from right whales cannot be matched to a specific fishery or site.
Strategies for Reducing Risk
In Providence next week, the Team will be developing and discussing potential measures to modify the Take Reduction Plan, including updates to the current gear marking strategy, seasonal area closures, and reducing the risk of vertical lines through the use of weak rope. Many of these measures were proposed by Team members during an October 2018 meeting to discuss possible options to discuss at the April 2019 meeting. In advance of this meeting, the team particularly requested two things: 1. Clarification of a target percent reduction in serious injury and mortality, and 2. An ability to evaluate and compare different risk reduction elements from Team proposals.
A Target Reduction Level
Based on the 2016 population estimate, the Northeast Fisheries Science Center’s North Atlantic right whale stock assessment establishes a potential biological removal level of 0.9 whales per year — i.e. slightly less than one whale suffering human-caused mortality or serious injury from any source in a given year.
Currently, NOAA Fisheries estimates that U.S. fisheries are responsible for 2.5 to 2.6 observed serious injuries and mortalities each year. Scientists estimate that we only observe 60 percent of the serious injuries and mortalities, which would bring the U.S. total to about 4.3. To get to 0.9 will require a reduction of 60-80 percent of serious injuries and mortalities.
A Risk Analysis Decision Tool
Determining how to judge the expected conservation value of any particular measure is a complicated task. To create a model to assess risk reduction, the model needs to first identify the current risk landscape, overlaying information on the density of trap/pot vertical lines, the distribution of whales, and the relative risk of the gear configuration associated with the lines (strengths/diameters of lines, lengths of trawls). Working collaboratively, the model combines Industrial Economics Inc.’s improved trap/pot vertical line model and the Duke Marine Spatial Ecology Lab’s marine mammal density model, as well as risk assessment weights provided by Take Reduction Team members, Agency large whale scientists and managers, and permitted whale disentanglers. With these data sets, scientists at NOAA’s Northeast Fisheries Science Center developed a risk assessment tool that will be used at next week’s meeting. This tool represents a substantial leap forward and provides the Team with the best available information to determine risk and support their deliberations.
Next Steps
After this meeting, we will use recommendations from the Team to begin rulemaking in May. At various points during rulemaking there will be a continued opportunity for public comment.
“I’m confident we have the right people around the table to tackle this problem,” says Mike Asaro, Acting Protected Resources Assistant Regional Administrator. “This is a complex issue but with the cooperation and active engagement from the people who know this issue best, I have hope that following the meeting, we will have a solid set of conservation measures to proceed to rulemaking that will allow the fishing industry and whales to coexist and thrive.”