By Heather Sadusky
Salmon is an aquaculture success story. Raised around the world from Scotland to Chile and sold to global markets from sushi restaurants to grocery stores as frozen fillets, salmon from both the Atlantic and Pacific oceans has become a mainstream food item.
In Alaska, there is a unique method of salmon aquaculture in practice that aims to bolster the natural fish stocks while also taking pressure off it. The state’s hatchery program was initiated in the 1970s to combat depressed salmon stocks and catch, and was instituted with a number of genetic and health regulations in order to protect wild stocks as production of hatchery fish began (ADF&G).
This aquaculture method utilizes the anadromous nature of salmon: when they return to their rivers of origin to spawn, the salmon are captured so that eggs and sperm can be harvested. This group of fish is referred to as the broodstock, and is required to be from a local source. The egg mixture is fertilized and incubated in a hatchery, where the fish stay for about two years, depending on the species. Once the juveniles reach smolt stage, about five inches in length, they are released into the river from which their parents came, and then begin the natural cycle of heading out to sea to eat and grow. During these two to three years at sea, many will be captured by commercial and recreational fishermen. The salmon that survive will return to their river of origin where the process begins again.
In this way, commercial fishermen are able to continue their regulated harvest of salmon without depleting the fishery. The enhancement afforded by hatchery production protects the natural stocks from overfishing while maintaining the fishing industry. It has been argued that salmon would have gone extinct if it were not for aquaculture, which has been able to supplement the stocks. This particular method is referred to as ranching, and is different from stocking.
Of course questions emerge as to the effects of natural salmon stocks mixing with hatchery salmon stocks, which is why Alaska has developed policies focused on the health of natural populations. Hatcheries are required to be located away from wild stocks, wild stocks are to be given priority in management, there are requirements for marking hatchery fish to distinguish them from wild, and studies on the interactions between wild and hatchery stocks have been instituted as part of the program (ADF&G).
These regional aquaculture associations abound across the state, and were initially funded by the fishermen who chose to tax themselves in order to support these organizations. After a near collapse of the fishery in the 1970s, Alaska’s salmon stocks are now managed sustainably, largely thanks to aquaculture.
Learn More: visit the Southern Southeast Regional Aquaculture Association, or the Kodiak Regional Aquaculture Association to see how it works.