The 2023 Atlantic Lobster Moult and Quality Survey (ALMQ), conducted by the Coldwater Lobster Association and the Université Sainte-Anne, found that the quality of lobsters increased from the previous year, while catch rates went down.
The surveys take place in lobster fishing areas (LFA) 33 and 34, where researchers take 150 sample lobsters in each of their eight predetermined survey sites. These sites are located in four general areas, each of which has an “inside” and “outside” component.
The surveys conducted in the ALMQ look for several biological characteristics in lobsters throughout the preseason, including shell hardness, moult stage, carapace length and sex.
According to Daniel Lane, an associate professor at the Université Saint-Anne, the most important metric for judging lobster quality is blood protein levels, or Brix levels, which measure the milligrams of protein per millilitre of blood.
“This is an indicator of where lobsters are in their moult and what that says about the meat content of the lobster in the carapace,” said Lane.
Another characteristic that Lane said has become more important in recent years is surveys for “weaks” — lobsters that show very little vigour and general lethargy. In recent years, these weaks have become more common within the survey areas around southwest Nova Scotia. Lane said much of the uptick in weak lobster prevalence has to do with a change in the moult timing of lobsters in the area or other contributing factors like stress.
“Over time, those weaks have generally increased in the last several years to double, triple levels to what we used to see,” said Lane. “Back in 2020, we were getting around three per cent weaks. Now, we’re getting closer to around 10 per cent weaks in some cases.”
Given that upwards of 90 per cent of Nova Scotia lobsters sold are destined for the live market, the increasing prevalence of weaks has been some cause for concern amongst harvesters. These weaker lobsters do not have the capability of surviving any significant length of time in storage or travel to international markets.
The dataset of the ALMQ goes back to the project’s beginnings in 2006, which gives researchers like Lane a “goldmine” of data to sift through regarding the health of lobster stocks in the area. Since 2020, when the Coldwater Lobster Association came onboard to provide an extended pre and post-season analysis, the most evident thing noticed by Lane and his colleagues is that catches have gone down, especially from 2022 to 2023.
“In both ’22 and ’23, we’ve had a fall in the counts of lobsters that we’re seeing in the pre-season traps,” said Lane. “The outside areas for St. Mary’s Bay and Yarmouth were quite low, and I’m talking on the order of 50 per cent down compared to 2022.”
Since 2016, which saw record-setting catch rates, catches have continued to trend downwards. Conversely, according to Lane, 2016 saw a “crisis in quality” for Nova Scotia lobsters that has since started to rebound as catch rates have gone down.
“If the moult period is delayed, for example, when you go out to catch these [lobsters] during a period when they’re still recovering, you’re not going to see them in the trap,” said Lane. “So, the indication might be, ‘Oh my god, the lobsters are disappearing. Their abundance is down.’ But it’s just a matter that there’s something going on with the population that the timing is off.”
In a post-moult fishery like LFA 33 and 34, the idea of beginning the fishery in November was intended to give lobsters ample time to recover from their moult. Warming waters, however, have elongated the moult periods of the population in the area.
“Not all lobsters are moulting earlier. They’re moulting later, and we get this situation where we’re getting weaks because they’re not fully recovered and we’re fishing them in any case,” said Lane. “In LFA 29, we fish in May and June. Those lobsters are coming off winter, they’re getting ready to moult in June and July when things warm up, but they’re fully-meated and ready to go.”
By late in the LFA 33-34 season in January, most of these lobsters have gone into a pre-moult stage where the lobsters are more robust and there are better catches. The issue, said Lane, is that many harvesters are rushing to meet the demand for Christmas markets before the lobsters have reached their peak quality.
“If the lobsters have experienced an elongated moult, then quality isn’t necessarily that good. That’s what happened in 2016. It’s happening less now — we’re getting better quality, but we’re not getting as good of catches,” said Lane.
“It could be a question of the moult timing, it could be a question of numbers or it could be a question of movement — where they are as opposed to where we’re used to catching, and they’re not there now that they’ve gone somewhere else. There’s a whole bunch of things that come into it, it’s not necessarily a population indicator that we see when we look at catches. Finfish, maybe it’s a different story, but these crustaceans are different.”
