Record-setting lobster landings have been the catalyst of late driving the fishery in the northeastern Atlantic.
Catches on both sides of the border have sustained an almost uninterrupted surge in abundance for more than a decade. By 2015, U.S. and Canadian harvests had nearly doubled — adding up to a combined volume of 157,000 metric tonnes (346 million pounds) with a value of (U.S.) $1.48 billion.
In eastern Canada, lobster landings have increased from just over 54,000 metric tonnes in 2006 to nearly 93,000 tonnes in 2016. (See table page 5)
All surveys by both U.S. and Canadian regulatory bodies leave no doubt that there has been a real and dramatic increase in lobster abundance, notably in the waters off Maine and southwest Nova Scotia.
However, the recently released 2016 American Lobster Settlement Index (ALSI) has highlighted some potential issues for North Atlantic lobster stocks in the near future.
The University of Maine-based ALSI is an annual monitoring program that quantifies the pulse of newly settled lobsters that repopulate rocky, coastal nursery grounds in New England and Atlantic Canada. Examining this segment of the lobster life history, according to the Index, is especially valuable because it is the only time when one can identify, with certainty, the strength of an individual year class. It is a pivotal life stage that both sheds light on the ocean processes that deliver larvae to nurseries and is useful as a predictor of future trends in recruitment to the fishery.
Initiated in 1989, the survey has expanded from a few sampling sites in coastal Maine to encompass more than 100 sites in other lobster-producing regions of the Northeast United States and throughout Atlantic Canada.
This year’s report has a lot of scientists involved with the survey scratching their heads. Just as U.S. and Canadian landings seem to be breaking all the records, lobster settlement has been dipping to all-time lows.
By all indications, according to researchers, the reproductive output of the homarus americanus population should be greater than ever, but for some reason it does not seem to be translating into record-breaking numbers of young lobsters.
Baby lobster densities in 2016 continued a downward spiral. Many areas reported some of the lowest settlement numbers on record since monitoring began and the list of areas reporting downturns seems to be growing. In the Gulf of Maine, most monitoring sites from Beaver Harbour, N.B., to Cape Cod Bay, reported some of the lowest settlement rates since the late 1990s or early 2000s.
Lobster Bay and St. Mary’s Bay off southwest Nova Scotia had a recent spike in 2014, but have since fallen off as well. Settlement along the eastern shore of Nova Scotia (Cape Breton and Canso) has been nil for the past three to four years. And researchers say it may be too early to tell, but the southern Gulf of St. Lawrence and Prince Edward Island seems to be sliding off its impressive surge that peaked in 2014.
In many cases, science has been at a loss to fully explain the recent exponential growth in lobster populations — with most pointing to climate change and an increase in water temperatures as key factors. But just as the increase is hard to explain, the nagging mystery is equally perplexing as to why settlement would be so low when the brood stock is at record-breaking highs.
One hypothesis of this problem has to do the survival rates of the lobster larvae. There is speculation that despite the abundance of lobster eggs, the larvae are not surviving due to such factors as rising numbers of predators, a shrinking food supply or unfavourable ocean currents.
The ALSI stated that one line of evidence hints that recent declines in zooplankton prey that lobster larvae eat may be a contributing factor.
Whatever the cause of the decline, the industry needs to step up and take notice of this disturbing trend that has been outlined in the 2016 Index.
“If we can generalize from this admittedly limited larval data set, the take-away is that larval production seems to be doing just fine, rising with the historic surge in brood stock. But times seem to have been getting harder for larvae as they run the month-long gauntlet from hatch to settlement. 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. Most importantly, this is a prime example of why spawner abundance and egg production has been a notoriously poor predictor of recruitment to so many fisheries, and why ALSI may be a useful bellwether for the future,” this year’s report concluded.
Every seasoned fisherman will tell you the lobster fishery is cyclical and has gone through boom and bust years in the past. So, with such worrying recruitment trends possibly on the near horizon, it is time for all stakeholders to take notice and plan for a possible lobster decline in coming years.
The once-depleted science division of the Department of Fisheries and Oceans has recently seen an injection of both funding and staff. If it has not already done so, it would be pertinent for DFO to devote significant resources to tackle this potentially negative impact to the multi-billion dollar Atlantic Canada lobster industry.
Unfortunately, many in this region have witnessed first hand how quickly fish populations can change and the dire economic circumstances that follow. In order to try and avoid another boom and bust scenario, science and industry must first understand the problem before solutions can be offered. Now is the time to face this issue head on — it can’t be left until harvesters start hauling up empty traps.
