As sea lice feast away on dwindling salmon, First Nations decide the fate of salmon farms

As sea lice feast away on dwindling salmon, First Nations decide the fate of salmon farms

VANCOUVER, Canada — Alongside the millions of Atlantic Salmon clustered in the open net pens that dot the waterways around Broughton Archipelago’s over 200 islands, sea lice, a tadpole-shaped parasite, feast on the fish. In the zeal to establish a salmon market northwest of Vancouver, Canada, many aquaculture companies set up open net pens—cage-like structures where a layer of fishnet separates the farmed salmon from those in the wild—in the 1980s. They were also, however, creating conducive conditions for the spread of sea lice, a blood-sucking parasite found on the aquatic animal. During one of their free-floating larval forms, sea lice attach to salmon, devouring their skin and sucking blood. In the Pacific waters, two species of sea lice are found—Caligus clemensi and Lepeophtheirus salmonis. Studies have shown that L. salmonis is abundant in pink salmon around salmon farms. Image credits by Sea Lice Research Centre. Every two years, wild adult pink salmon (Oncorhynchus gorbuscha) swim upstream from the oceans to the gravel beds of the many rivers and creeks where they lay eggs and die. After a few months, the eggs hatch and the young salmon, called smolts, make their way back to the open ocean. Image by Erector/Wikimedia Commons. By the early 2000s, communities living in the archipelago began noticing wild juvenile pink salmon—native fish of the Pacific Ocean that aren’t gathered in the pens—returning from their freshwater spawning grounds also infested with the lice. These fish were on their way to the ocean, swimming near the salmon farms and through the meandering inlets—a path…This article was originally published on Mongabay

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