The Department of Fisheries and Oceans (DFO) has said that lobster stocks in the Maritimes are in great shape, but the future of our oceans could have major implications for the health of the stock.
Every lobster fishing area (LFA), including the highly lucrative LFA 33 and 34 off of southwestern Nova Scotia, remain firmly in what DFO terms the “healthy zone.” That said, landings have dwindled over the last half-decade and DFO scientists are unsure if this is a natural cycle or part of the ever-looming threat of the times that is climate change.
Studies have shown that, for now, Canada’s warming oceans have proven quite comfortable for the lobster population. As ocean temperatures warmed, lobsters have slowly but surely been migrating north from the eastern seaboard of the United States to the Scotian Shelf, the Newfoundland and Labrador Shelves and the Gulf of St. Lawrence, where the ocean waters are nestled well within their “comfort zone” of around 10 to 16 degrees.
This crustacean exodus has benefitted Atlantic Canada for the time being, but with temperatures steadily climbing year after year, with temperatures expected to increase between one and four degrees by 2100, the luck of our local fish harvesters may not last forever.
While the bottom of the Scotian Shelf may not see temperatures soar above that lobster comfort zone any time soon, one must also be aware of marine heat waves. Take 2012, for instance, where the northwest Atlantic was 2.5 degrees warmer for 56 consecutive days. While heat waves are partially natural, according to a 2019 climate change report “there is growing confidence that the observed intensification of heatwaves is due to human activities.”
These heatwaves aren’t just uncomfortable for lobsters, who outside of their comfort threshold can experience distress and even death, but for their habitats as well.
Seagrasses and kelp forests, which many lobsters call home, can be devastated by unseasonably hot temperatures. With nowhere to go, lobsters tend to scuttle north to a more comfortable environment and stay there. Currents matter as well, with DFO noting in a 2018 publication that the warm waters brought north by the Gulf Stream have an increasing influence compared to the colder temperatures brought south by the Labrador Current.
All these compounding warming trends, shifts in currents and outlier heat wave events have the potential to compound into a troublesome situation for Canada’s richest lobster fishery.
Then there’s acidification. As we pump out more and more carbon dioxide, the ocean ends up absorbing greater amounts of our output. According to the Marine Stewardship Council, 83 per cent of the global carbon cycle is circulated through the world’s oceans.
This carbon dioxide dissolves in our oceans and forms carbonic acid. On average, the Scotian Shelf pH balance has decreased by an average of 0.03 pH units per decade. This may not sound like a lot, but even a 0.03 decrease in pH increases the ocean’s acidity by 6.7 per cent, according to DFO.
The ever-increasing acidity of our seas makes the waters that many in Atlantic Canada rely on for their income corrosive to calcium carbonate — the main building block of lobster shells. These corrosive conditions compounded with high temperatures can suppress lobsters’ immune systems and lead to shell disease.
There’s no turning back the clock on climate change.
The best we can collectively do is reduce our carbon emissions as quickly as possible. We’ve all heard about alternative energy sources and personal lifestyle changes, but changes in the fisheries themselves can be a part of the solution.
The first step, by and large, is reducing fuel consumption during the fishing season. While fuel is and will likely always be a factor when it comes to fishing trips, there is always room for fuel-efficient improvements and changes.
For one, a change in fishing gear can make a huge difference. A study in Norway has found that applicable fisheries that change from trawling to trap fisheries reduce the amount of fuel burned for every kilogram of catch by 75 per cent. Passive gears, in general, are some of the most effective ways of reducing a fleet’s carbon footprint.
Another solution is simply doing the utmost to keep fish stocks strong.
An overexploited or unhealthy stock is, by default, going to be more spread out than a healthy stock, which is going to increase the effort and fuel required for harvesters to bring in their total allowable catch of said stock. By keeping marine habitats healthy and fishing efforts low, both harvesters and the planet at large can benefit.
With options like biofuel, electric and semi-electric propulsion systems and other alternative fuels gaining ground, adopting these technologies could play a big part in making the fisheries cleaner and greener. Design changes can also be a major factor, such as in a 2013 study on Basque trawlers where a change in the design of the trawl doors reduced fuel consumption by 15 per cent.
Lastly, despite all the improvements that can be made, eating seafood as an alternative to other proteins can reduce carbon emissions. Wild fisheries produce less carbon than beef, mutton, cheese, pork and poultry, according to Oceana, only being beat out by eggs, milk and aquaculture.
So, if you can only do one thing to make a difference in the future of our fisheries, eating more fish is a good start.
