The Eastern Canadian oyster: economy booster, sustainability driver and (possible) aphrodisiac

Luke Poirier, PhD, Natural Sciences and Engineering Research Council of Canada Visiting Postdoctoral Fellow

Driving slowly down Hurd’s Point Road in Western Prince Edward Island shortly after sunrise, the horizon is dotted by small dories manned by fishers hunched over their long oyster tongs, probing the seafloor below for the Eastern oyster (Crassostrea virginica). The water here is brackish, meaning it is slightly salty, a result of a mixture of inflowing freshwater and nearby seawater from the Gulf of St. Lawrence. However, using generalities like “this bay is brackish” when it comes to oysters is akin to saying “this wine is red.” Oysters, like wines, take on a variety of flavours depending on their growing location, creating distinct regional flavour profiles. No longer affixed with a blanket name like “Malpeque,” clever marketing by producers and fishers has resulted in a wave of varieties being featured in restaurants around the world.

These early morning Bedeque Bay fishers are purveyors of P.E.I.’s “wild oysters,” which are known for their sweet and salty taste, with a meat that is lean and full. These oysters are also known for their long jagged shells, a result of their uncultured development – a six-year undisturbed growing period on the seafloor. Fish harvesters rely on natural recruitment processes to ensure their product remains sustainable; and through enhancement programs, their wild beds will be producing oysters for years to come.

Not far away, on the other side of the Northumberland Strait, a large oyster barge moves out onto Caraquet Bay, New Brunswick. Here, oysters are cultured. That is, grown from spat, which are baby oyster larvae that have settled from the water column and have been collected by fishers who then grow them out in suspended or floating cages. Over the course of three to five years, these oysters are tended to by diligent aquaculturists who desire a deep cup and round shell that provides a symmetrical look when a half dozen are on display in oyster bars the world over. This region produces oysters that are known to have a firm texture with a mild brine taste, an excellent introductory variety.

Wild and cultured oysters contribute both to Atlantic Canada’s economy and the environment in multiple ways. The economic benefits are much more visible than the environmental ones, but did you know oysters are considered ecosystem engineers? This means that oyster beds provide habitat for many other species, and they provide structure to the seafloor that can stabilize erosion. Furthermore, oysters are notoriously good filter feeders, so in the process of filtering water for phytoplankton, they also remove impurities. In fact, an adult oyster can filter upwards of 180 litres of seawater a day!

Beachcombers and shuckers alike, hoping to find a pearl in an Atlantic Canadian oyster, should temper their expectations. Unlike their cousins, the noted large pearl-producing gold-lipped oyster (Pinctada maxima), Eastern oyster pearls are extremely rare and small. Pearls are produced when a foreign object (usually a grain of sand) enters and gets wedged between the oyster’s mantle and shell. This irritation causes the secretion of nacre, which is also what makes up the majority of an oyster’s shell. The oyster continually coats the grain of sand in nacre until a pearl is formed. Keep searching, but don’t get your hopes up.

There are also misconceptions about the aphrodisiac properties of oysters. While they were a preferred food of the famed historical lover Casanova, they have not yet been scientifically proven to increase or enhance desire. They do, however, contain high levels of zinc, which is an important contributor to testosterone production as well as amino acids and serotonin, which can impact the neural pathway of the pleasure or happiness response. But for those who swear by their effects, more likely it is the setting in which they are typically enjoyed – a romantic evening indulging in a sustainable and delicious marine food with a loved one.