Natural pigment vs. synthetic colour?

The flesh of wild-caught salmon is deep pink or red, because wild salmon feed on crustaceans rich in carotenoids, including astaxanthin, a red pigment found predominantly in the flesh or outer shells of marine creatures, responsible for the red-orange or pink colour of krill, crabs, red micro-algae, salmon roe, arctic shrimp, crayfish, red trout and lobster.

Astaxanthin (and the yellow carotenoid pigment zeaxanthin) is found in red-coloured birds that eat seafood and other marine creatures rich in red pigments, including crustaceans, small fish, blue-green and red algae, and diatoms. Think of a distinctive red puffin bill, the bright pink feathers of a flamingo, or the subtle pink blush faintly visible in seagull plumage.

Farmed Atlantic salmon feed primarily on pellets made from a combination of ground-up fishmeal sourced from wild fish and conventionally grown, often genetically modified, grain or soy treated with fossil fuel-based pesticides. Farmed Atlantic salmon flesh is greyish-white, so synthetic colour must be added to feed to turn their flesh light pink.

Nutritional status of wild-caught fish vs. farmed fish

Wild-caught salmon is far superior to farmed salmon in terms of taste and nutrition, feeding on food nature physiologically designed them to eat – zooplankton, wild fish and marine invertebrates – not grain and soy their bodies cannot effectively metabolize.

Wild-caught salmon are healthier than farmed Atlantic salmon. Because they swim freely in the ocean, they possess natural immunity and built-in resistance to disease, unlike farmed fish with compromised immunity. Farmed Atlantic salmon are raised in unsanitary conditions, in waters polluted by their own excrement, and in overcrowded pens, breeding grounds for disease-causing bacteria and parasites. Farmed Atlantic salmon are given high doses of antibiotics to control illness and disease and may be fed growth hormones (see Farmed Fish & Atlantic Salmon under Impacts).

Harvesting methods for wild-caught fish vs. farmed fish

Wild-caught fish may be harvested using large-scale, non-selective, industrial methods of extraction that result in high incidence of bycatch of non-targeted species that are thrown back into the ocean, dead, dying or injured (see Bycatch & Incidental Capture of Cetaceans under Impacts).

Farmed fish are slaughtered using inhumane, slow, painful and distressing methods, including asphyxiation in air or on ice, exposure to carbon dioxide or extremely low temperatures, bleeding while unconscious, stunning, live chilling or gill cutting. There are ethical and animal welfare issues around the ability of fish to feel pain.

Industrial pollutants in wild-caught fish vs. farmed fish

Wild-caught fish may be contaminated with industrial pollutants that enter rivers, lakes and the ocean. Fish absorb these pollutants from the water as they breathe, from suspended sediments, but mainly via their food. Species higher on the marine food chain bio-accumulate more pollutants over time. The larger and older the fish, the higher the concentration of mercury in its flesh, from eating fish that have eaten other fish, low on the marine food chain.

Farmed fish may have lower concentrations of mercury and other pollutants in their flesh because they often eat a more controlled diet consisting of a higher proportion of grain-based feed, and less fishmeal made from ground-up wild-caught fish.

Restoring wild salmon populations

Many wild salmon fisheries have been or are being over-exploited and there is no longer enough wild salmon to feed the entire human population. The North American group of Atlantic salmon were once native to almost every river system north of the Hudson River, but are now only found in Maine (NOAA 2021).

Alexandra Morton has devoted the last three decades of her life fighting to save the wild Pacific salmon of British Columbia, not only for the salmon, the keystone species of the region, but for the northern resident Orcinus orca (Killer Whale) populations she has loved and studied her entire scientific life. Pacific salmon are threatened by impacts from Atlantic salmon aquaculture. Alexandra’s remarkable story is documented in Not on My Watch: How a Renegade Whale Biologist Took on Governments and Industry to Save Wild Salmon.

The southern resident Orcinus orca (Killer Whale) population of 78 individuals that feed on wild Chinook salmon are Endangered, with the leading cause of their decline being insufficient prey (see Marine Food Webs & African Penguins under Impacts).

© 2016 – 2021 Seafood Free September

REFERENCES:

Alexandra Morton, https://www.alexandramorton.ca/

NOAA Species Directory, Atlantic Salmon, https://www.fisheries.noaa.gov/species/atlantic-salmon

Wild Salmon, https://www.wildsalmon.org/