Sustainable fisheries: Facts and figures

A topic of interest to society is responsible fishing and seafood farming worldwide, but when you buy a seafood product in a fishmonger's shop, can you tell whether it is wild or farmed? And how exactly are the fish raised in a fish farm?

The annual increase in average fish consumption has surpassed the consumption of all land animals combined. Since the 1980s, the capture fishing industry has been on the rise; today, aquaculture has helped meet growing consumer demand.

Given the importance of aquaculture, here are two common farmed fish species you've probably seen at the fish market, as well as the story of how they got there.

• SALMON

Salmon is one of the most popular fish on the market, and is almost a must on menus around the world. Recent technological advances, selective farming and its high market value have made this pink-fleshed fish available to meet customer demands. Farmed salmon accounts for more than 70% of the salmon market, so it is likely that if you have eaten this fish, it is farmed.

WILD SALMON

Wild salmon are generally caught, depending on the species, by hook and line, trawl or purse seine. These fish, before being caught, are born and grow in their natural habitat. Although the catching process can be harmful to the fish and the environment, there are strict rules and regulations for both commercial and recreational fishing that specify the months of the year when fishing is allowed, the catch materials that can be used, and the amount that can be caught. For more information, a quick online search of your country's government regulations will provide you with all the answers you need.

FARMED SALMON

Farmed salmon, on the other hand, result from the careful selection of the largest brood fish. To raise a new generation of fish that exhibit the desired traits, brood fish are chosen based on desirable genetic characteristics that will be passed on to their future offspring; these characteristics include fish size, fat content, physical appearance, and fish health. Typically, eggs and milt are collected and the offspring are kept in hatchery trays or in land-based rearing tanks.

Aquaculture Recirculation Systems (ARS) in fish culture tanks minimize unnecessary water use while allowing factors such as temperature, oxygen and salinity to be carefully controlled. 2019.

In the sea pens, the fish remain for at least another 18 months until they grow large enough (~5 kg) to be harvested with floats or seine nets. The farmed salmon are then fished to prepare them for commercial handling.

The color says a lot about salmon

Wild salmon eat a diet based on shrimp and krill, and it is thanks to the algae pigments they consume (astaxanthin and canthaxanthin) that give their flesh a deeper reddish orange color. In a fish farm, salmon are fed feed, or pellets, which generally contain a mixture of fishmeal (composed of small fish of low nutritional value, bycatch, offal and trimmings), fish oil and other vegetable-based compounds, which do not contain the same pigments as the algae. Some agricultural producers, concerned about reducing the impact on marine species, have begun experimenting with insect-based feeds; because these pellets lack krill and shrimp, the flesh color of farmed fish is grayish.

To compensate for the lack of pigmentation, astaxanthin is often added to the feed to give farmed salmon their characteristic color. However, not only does this pigment give wild salmon their distinctive pink color, it is also associated with higher levels of Omega-3. Farmed fish tend to have diets lower in Omega-3, so their flesh does not have the same intense color as wild salmon.

Price

Wild salmon generally has a much higher price, especially in the case of fresh fish. If it is cheap, it is most likely from aquaculture.

MSC and ASC labels

One way to ensure that the wild salmon we buy is sustainable is to look for MSC (Marine Stewardship Council's sustainable fishing standard) or, in the case of farmed fish, ASC (Aquaculture Stewardship Council) certification. These certifications are only awarded to products that have been evaluated and meet a series of sustainability criteria throughout the process. It is important to note that this does not necessarily mean that all fisheries without an MSC label or ASC certificate are not sustainable in practice.

The high cost of this label can be detrimental to small producers who cannot afford certification. Therefore, tracing the origin of the fish we consume can provide important information about its provenance. If you can't see where it comes from, or how it got to the store, you may want to think twice before buying it.

• TUNA

espite what many people think, farmed tuna represents less than 1% of the total tuna market.

All the tuna you normally eat for sushi, or even canned, is wild caught. The only tuna species that is farmed commercially is bluefin tuna, although yellowfin tuna is now farmed in small-scale experimental farms. However, farmed tuna is rarely found in supermarket cans. Instead, it is sold in markets or exported frozen to high-end restaurants.

WILD TUNA

Wild tuna are generally caught using purse seines, trawls or hook and line. But to help control tuna populations, the amount of tuna catch allowed and the gear used are strictly regulated. Unfortunately, the increased demand for canned tuna is putting great environmental pressure on the population of several tuna species.

FARMED TUNA

Unlike salmon or terrestrial species, we cannot yet rely on tuna stocks that are reared in tanks. The limited success of spawning rates and juvenile fish in controlled environments has led tuna producers to opt for open water 'ranching'.

The open-water 'ranching' method uses purse seine nets to capture schools of juvenile tuna. The fish are then transferred through underwater gates to floating sea cages where they are farmed for months, or even years, before they are marketed.

Price

A good rule of thumb that applies to most endangered species is this: if you can't live without your wild-caught fish, then be prepared to spend. Wild tuna costs up to three times as much as farmed tuna.

Ultimately, if you already make an effort to choose a fish based on its sustainability, what most consumers want is an honest market that includes timely provisions on wild or farmed catch, a safe bet is to be aware of the MSC or ASC certifications of the fish you buy. Checking that your purchase includes one of these certifications is a good way to know if your fish comes from sustainable production, as they are included in all our Pescatore Seafood products.