NOAA findings on right whale endangerment could affect lobster fishery
A new report by the National Oceanic and Atmospheric Administration’s Northeast Fisheries Science Center finds that the decline of the North Atlantic right whale population over the past eight years is due to multiple factors that include entanglement with fishing gear.
The whales’ range expansion has exposed them to vessel traffic and fisheries in Canadian waters, which did not have protections for right whales in place until late last summer, the report says. Lobster populations are also changing distribution in the Gulf of Maine, causing U.S. fisheries to move farther offshore in pursuit of lobsters, thus increasing overlap between fishing activity and right whale foraging areas and migration corridors. Shifting distribution patterns correlate with shifting ecosystem conditions.
“The net result of these events is that severe entanglements have increased among North Atlantic right whales,” the report says. “Animals are in poor body condition likely from a combination of repeated entanglement stress, potentially limited forage and increased migratory costs- all contributing to a decrease in female calving rate. Ship strikes are still a real threat to the population. At the current rate of decline, all recovery achieved in the population over the past three decades will be lost by 2029.”
In 2017, there were 17 right whale deaths, and two, to date, in 2018. Only five calves were born through 2017 up until August 2018. Cause of death was determined for 10 of the incidents. Ship strikes were implicated in five blunt force trauma cases and entanglement in five. In 2017, seven other entangled whales were observed: three were disentangled, three shed the gear, and one was not seen again.
“Taken together these signs meant that risks posed to right whales and associated management measures needed to be revisited for multiple U.S. fisheries on the Atlantic coast,” the report says.
The right whale population in 2010 was estimated to be 481. By the end of 2016, the population had declined to 451.
“A revised population estimate accounting for the many deaths and few births of 2017 is being developed and will be available later this year,” the report says.
In the U.S., since 1997, a series of measures were implemented to reduce entanglement risk, including a rule in 2015 that removed 27,000 miles of vertical fishing line - which attached lobster traps on the bottom of the ocean to buoys on the water’s surface - from the water column.
However, says the report, the 2015 rule might have resulted in an unintended consequence. Because the rule required “trawling up” – attaching more traps to a single line – in some regions, stronger line was required by the lobster fishery to accommodate the increased load of multiple traps. That adaptation has contributed to an increase in the severity of entanglements, the report says.
“Rough estimates are that approximately 622,000 vertical lines are deployed from fishing gear in U.S. waters from Georgia to the Gulf of Maine,” the report says. Together with fishery zones around Nova Scotia and into the Canadian Gulf of St. Lawrence, these fisheries exceed an estimated 1 million vertical lines deployed throughout right whale migratory routes, calving, and foraging areas.
Maine’s lobster interests continue to address the problem. In April, the Maine Department of Marine Resources was awarded a $714,245 grant from NOAA to improve data used to protect endangered North Atlantic right whales. The three-year project was designed to support work that improves and adds data on fishing gear that can inform future whale protection regulations.
In August, the Maine Department of Marine Resources posted a notice to lobster fishermen, asking them to participate in a survey on how vertical lines are rigged and fished. Information will include rope type and diameter, trap configuration, distance from shore, depth, and type of surface system. The survey includes harvesters from Maine, New Hampshire, Massachusetts, Rhode Island, and Connecticut and offshore areas.
“Without a better understanding of vertical lines, regulators are more likely to implement sweeping regulations which might not be any more effective at protecting whales,” the notice said. “Good information from industry, including these surveys, will increase the likelihood of targeted, effective regulations.”
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