Mr. Chairman and committee members, thank you for inviting me to speak with you today about lobster and snow crab ecology and fisheries.
My name is Arnault Le Bris, and I am a research scientist at the Fisheries and Marine Institute of Memorial University of Newfoundland. I define myself as a fisheries ecologist, addressing issues relevant to the fishing industry and to the sustainable management of marine resources.
As part of my current research on a variety of marine species, including lobster, I'm working with fishing associations from four provinces in Atlantic Canada and Quebec, with members from both the inshore and offshore fishing industries and with federal scientists from three regional centres of Fisheries and Oceans Canada.
My presentation will focus on three issues. The first is the concept of movement in lobster and snow crab. The second is the problem of carapace size in the lobster fishery. The third, and most important, in my view, is the need to anticipate the future.
Issue number one is the movement in snow crab and lobster.
There are two types of adult movement: seasonal movements and alongshore movements. Seasonal migration from shallower water to deeper waters has been well documented in both lobster and snow crab. While this type of movement affects where the resource is distributed across seasons, it does not really affect whether a lobster or a snow crab moves from one fishing area to another.
The second type of adult movement is alongshore movement. This has the potential to cause movement across fishing areas. However, all tagging work conducted to date suggests that there's very little movement across lobster or snow crab fishing areas. Indeed, lobster and snow crab move alongshore in the order of tens of kilometres, which is enough to connect some fishing ports, but rarely enough to connect fishing areas, as demonstrated by the recent studies from the Lobster Node project.
Issue number two is minimum and maximum landing carapace sizes in the lobster fishery.
Throughout Atlantic Canada, minimum landing sizes are imposed in lobster fisheries. The rationale is to help lobster reproduce at least once before they are caught in the fishery. However, most of the minimum landing sizes are currently situated below the length at 50% maturity. This means that only a minority of lobster reproduce before they become vulnerable to the fishery. Increasing the minimum size, as was recently done in P.E.I., improves the chances that lobsters will reproduce. This increases the egg production in the population and consequently the resilience of the fishery to future changes in the ecosystem.
Another solution to increasing the egg production is to protect larger lobsters and especially larger females. Fecundity increases exponentially with size. For instance, a female lobster with an 85-millimetre carapace length produces about 10,000 eggs, while a female with a 110-millimetre carapace length produces about 50,000 eggs, which is about five times more. Another advantage of preserving larger females is that they reproduce more often. Preserving large reproductive females can be achieved through various conservation measures, including maximum size limit, throwing the egg-bearing female back in the water, v-notching and fishing gear selectivity.
As stated by my colleague Dr. Andrew Pershing, our work has demonstrated that the use of various conservation measures in Maine amplified the temperature-driven recent boom observed in the fishery.
In Canada, maximum size limits are not imposed. However, the combination of fishing season, the practice of v-notching in some areas and the general low selectivity of traps for larger individuals ensures that some large females remain in the water. How many large females are in the water is, however, unclear. Naturally, there are a lot of economic consequences of imposing minimum and maximum size limits, and especially market consequences, but I'm not an expert in that domain.
Issue number three is on anticipating the future.
I had a slide to show to you, and I don't know if it's on your screen right now. I wanted to show you a figure that summarizes the landings in fishing area 34 in southwest Nova Scotia from 1892 to 2016. The figure for landings in that area, which is very representative of the overall lobster landings for Maine and Atlantic Canada, shows that despite some ups and downs, landings were relatively stable for about 100 years, until the last 20 years. Quite suddenly over the last 20 years, we've experienced a massive boom in lobster landings.
This raises two very important questions: first, what has driven this rapid boom; and second, what will happen in the future? Responding to the first question helps to inform the second one.
In our previous work, we demonstrated that large-scale ocean warming has been favouring recruitment in northern regions like Maine, the Maritimes and possibly Quebec and Newfoundland, as some signs indicate nowadays. However, we don't fully understand the mechanism by which temperature affects recruitment. Is it through changes in the food availability for larvae lobster or through direct effects on growth and survival of food chains in the community of predators present in the system?
We need to better understand how climate change and ecosystems drive the recruitment process and also how predation affects the mortality of juvenile and adult lobsters. I think this is true for lobster but also for snow crab and, I will add, for shrimp.
Fisheries and Oceans Canada does a very good job of assessing the status of the resources. The next and most difficult step is to better understand the climate and ecosystem mechanisms that are driving the productivity of fish stock. Some work is being done on that, but we need to increase our science capacity around those questions, especially if we hope one day to predict future fisheries' productivity.
This brings me to the last point. Looking again at the figure that I was supposed to show you, I hope that everybody realizes that we are in a situation never experienced before. This is not the norm. The current landing of lobster in Canada is not the norm, and we need to keep that in mind.
Thanks to favourable ecosystem conditions and the hard work of the industry as a whole, the catches are at record highs, and the prices have been really good. This is fantastic, and I truly hope it lasts as long as possible. However, what will happen if the catches start to decline by 20% or 30%? What will happen to the thousands of harvesters and plant workers and to the hundreds of fishing communities that rely almost exclusively on these unique resources? This is a conversation that needs to happen sooner rather than later.