Did you know that shrimp is the most popular seafood item in North America?
Along with tuna and salmon, shrimp is one of the most consumed seafood in Canada. British Columbia is fortunate to produce four main species of commercially harvested shrimp: sidestripe shrimp, humpback shrimp, pink shrimp, and spot prawns. All four species are Ocean Wise recommended, but spot prawn season in particular is celebrated every year. I guess you could say spot prawns are seen as the darlings of sustainability in our own backyard.
Fun fact: Spot prawns are the largest of all the shrimp caught in Canada and every spot prawn starts its life as a male.
These shrimp reach reproductive maturity when they are one year old and once they turn three the males transform into females. This biological phenomenon is more common in nature than you would think. Why does this occur, you might ask? It’s an evolutionary adaptation to a life strategy that is the most beneficial to their survival. The reproductive potential of a female spot prawn generally increases the larger her size. So, when a spot prawn turns three and reaches an optimal size, it turns into a female in order to increase the number of offspring it produces.
Pretty smart, wouldn’t you say?
Females carry thousands of fertilized eggs on their underside from October to April. When it is time for the eggs to hatch, the females raise their abdomen, flap their pleopods (legs) and release the eggs which hatch immediately. Shortly after the larvae hatch, females leave the rocky habitats of the fishing grounds for deeper water.
This brings us to the sustainability of the spot prawn fishery which is closely linked to the spot prawn lifecycle. British Columbia’s coveted spot prawns are only available for six weeks out of the year beginning in May. By targeting spot prawns only after the females have spawned fisheries allow the population to replenish itself for future fishing seasons.
Spot prawns are caught using baited traps which are set on the ocean floor avoiding sensitive areas such as glass sponge reefs to minimize habitat damage. Sometimes the traps catch undersized spot prawns which cannot be legally kept, and other sea animals such as giant Pacific octopus. Due to the immobile nature of the traps, the bycatch species can be released back into the ocean unharmed.
Thanks to scientists, divers, fishers and Vancouver Aquarium’s Ocean Wise partners who are working together alongside Fisheries and Oceans Canada to ensure the continuation of this sustainable harvest, spot prawns remains an Ocean Wise recommended seafood. To find out more information about spot prawns check out: Keeping Spot Prawns Sustainable.
Enjoy the local spot prawns and have a happy spot prawn season.
Blog post by Claire Li, Vancouver Aquarium Ocean Wise Account Representative