HomeEnvironmentCommentary: Fishery over-dependence on lobster a ‘gilded trap’ scientists warn

Commentary: Fishery over-dependence on lobster a ‘gilded trap’ scientists warn

Last month in this space, I wrote abundant lobster catches over the past several years are likely a bubble, and suggested supply sustainability could turn out to be a much greater challenge for the future of Atlantic Canada’s lobster fishery than finding new markets.

With the effects of climate change bearing down on the region, the resource is unlikely to prove adequate to sustain current exploitation levels, let alone support significant lobster market expansion in Asia and Europe.

Scientists studying the Gulf of Maine lobster resource are sounding the alarm. The American Lobster Settlement Index (ALSI), a U.S.-Canadian monitoring collaboration of fishers and scientists founded in 1989, tracks newly-settled lobsters that repopulate coastal nursery grounds at more than 100 sites in New England and Atlantic Canada. In a 2016 ALSI update, organization founder Rick Wahle, a research professor in the University of Maine’s School of Marine Sciences, says despite the current abundance of egg-bearing adult lobsters and record-breaking harvests in the Gulf of Maine, the number of young lobsters continues to decline.

Most monitoring sites from Beaver Harbour, New Brunswick to Cape Cod Bay report some of the lowest lobster settlement rates since the late 1990s or early 2000s.

The watchdog organization, whose Canadian participants include the Department of Fisheries and Oceans Canada, the University of New Brunswick, the P.E.I. Fishermen’s Association and the Guysborough County (Nova Scotia) Inshore Fishermen’s Association, notes a trend of high egg production, but declining numbers of baby lobsters since about 2007. This could have profound implications for the region’s marine economy.

“If we were to see a collapse in the lobster catch, it would mean we’re already seven to eight years into a decline in the population,” Wahle says in a UMaine release. “Through ALSI, we can get an early warning of what might happen to the catch.”

So far, Maine lobster landings have been stronger than ever, with 2016 a record-breaking year for the state’s commercial lobster fishers in both volume and value. The Portland Press Herald reported more than 130 million pounds, or US$533.1 million worth, of lobsters were landed last year.

Approximately 80 per cent of New England lobster landings come from Maine coastal waters. With about three-quarters of the state’s overall fishery value deriving from lobster, “a downward trend in lobster production could significantly impact the state’s coastal economy in the future,” Wahle says, noting American lobster is now the nation’s most valuable fishery and Maine’s single most-valuable export — worth $331 million in 2015.

Even with current record harvests, signs of supply-side stress are appearing. McDonald’s Restaurants recently announced it won’t have McLobster sandwiches on the menu this summer due to high cost of lobster.

UMaine reports that scientists and fishers seeking to better understand the changing lobster population, and what those changes could mean for the marine economy, are finding a new data time series is shedding light on the puzzle of why settlement is falling at a time of increased egg production.

Wahle says larval lobsters hatch in early summer and are released into the water where they become better swimmers in ocean currents. Over the next four to six weeks, the larvae mature to their post-larval stage and settle on the seafloor. He suggests that changes in quantity or quality of food lobster larvae eat during the transition interval could be a mortality factor. An increase in waterborne predators of both lobster larvae and the also-monitored copepod Calanus finmarchicus, a form of zooplankton and major food source for larval lobsters, could also be factors. Studies do show the lobster settlement downward trend has paralleled declining abundance of copepods.

“Clearly, we need to better understand these linkages to know whether larval food supply could be a limiting factor in recruitment of Gulf of Maine lobster and the implications of these trends for the future of the fishery,” Wahle says.

Wahle recently co-chaired the 11th International Conference and Workshop on Lobster Biology and Management, held this year at Portland, Maine from June 4 to 9. The 2017 ICWL conference focus was on the impact a changing ocean environment is having on the global economy and the biology and business of lobsters.

Participation in ICWL conferences, held every three to five years, is typically about 200 lobster biologists, oceanographers, lobster fishers and fisheries managers representing 15 to 20 countries. Conferences were held at Saint Andrews, New Brunswick in 1985 and at Charlottetown, P.E.I. in 2007.

In a conference presentation, UMaine professor Robert Steneck noted over the past 20 years, economic diversity of marine resources harvested in Maine has declined by almost 70 per cent, with highly abundant lobsters now representing 70 per cent of the value of Maine’s fish and seafood landings. He observed, ironically, Atlantic herring harvested for lobster bait is the state’s second most valuable commercially fished species, albeit accounting for just 2.6 per cent of 2016 commercial landings.

Steneck warns that corrected for inflation, income from lobsters in Maine has increased by nearly 400 per cent since 1985. While many fishers, fisheries managers and policymakers consider this a success, what has essentially become a monoculture fishery increases social and ecological risks should anything happen to the lobster.

Steneck points to southern New England where summer ocean temperatures are rising with increasing frequency above the 20 degree threshold where lobsters become thermally stressed. This has caused massive die-offs and disease, resulting in a more than 70 per cent decline in lobster abundance and calls for lobster fishery closure.

A conference presentation by Rutgers University Assistant Professor Malin Pinsky observed the warming impact of climate change appears to be advancing substantially faster in the ocean than on land. This puts marine biologists and fisheries managers on the front lines of adapting to the changes. Many marine species are shifting poleward or deeper, lobster being one of the clearest examples.

While water temperature in the Gulf of Maine is currently close to ideal for lobsters, Wahle says, continued warming is heightening concerns a similar collapse in Maine poses a threat to the social and economic stability of the state’s coastal communities. The booming Maine lobster fishery is aptly described by Steneck as the sort of “gilded trap” that results when economically lucrative near-term opportunities “outweigh concerns over associated social and ecological risks or consequences,” with large financial gains creating a strong reinforcing feedback that deepens the trap.

Steneck says avoidance of or escape from the trap will require managing the fishery for development of increased biological and economic diversity. He concedes this is a difficult sell when no crisis has yet materialized, and financial incentives for maintaining the status quo remain large. However, he contends the fishing community needs to start thinking and talking about shifting fisheries management focus away from single species and toward integrated social-ecological approaches that diversify local ecosystems, societies and economies.

Similar observations can be made about heavy dependence on lobster in Canada’s Atlantic provinces fishery. Julie Gelfand, commissioner of the Environment and Sustainable Development at the Office of the Auditor General of Canada, concludes in a report released last fall that Fisheries and Oceans Canada didn’t always apply key planning elements to ensure management decisions for selected fisheries are focused on conservation and sustainable use. Her report says DFO’s assessment of Atlantic Canadian lobster stocks “does not take into account recent changes in the ecosystem of the new, more efficient fishing methods.”

The report prudently recommends DFO set priorities and timelines for identifying measures to be taken if a major stock falls below a certain level so that sustainable fishing limits can be determined with greater certainty. However, achieving agreement on what form such enhanced conservation measures would take, such as boat catch quotas or reduced numbers of fishing days in addition to current trap limits, will be a fraught issue itself.