Cameron Miller, Deneki Outdoors
Sea Lice
Lepeophtheirus salmonis. He's a picky parasite - he likes salmon and steelhead.
Deneki Outdoors
For anglers who like chasing salmon and steelhead, sea lice are a topic of great interest for a couple of reasons. Mike Sanders, our general manager, gives us the rundown!
What Are Sea Lice?
Sea lice are planktonic (adj. – of or relating to plankton) fish parasites that live in sea water. They thrive in tidal or protected areas. They attach to the outer body and feed on mucous, skin and blood of salmon and steelhead they like most anadromous fish actually. We have really good reason to hate them but there is a pretty cool aspect to them as well – such is life eh?
Why We Love ‘Em
Sea lice attach themselves to most adult salmon as they swim through fertile lice grounds on their return to rivers to spawn. Sea lice can not survive for long in fresh water. For that reason – when we catch a fish at BC West or Alaska West that is covered with sea lice and we do that a lot – we know that fish has just entered the Dean or the Kanektok.
Sea lice carry their eggs in two long eggs sacks that look like tails. Whether it’s true or not – legend has it that the tails fall off the lice long before the lice dies in fresh water. A fish with lice is fresh but if the lice have tails (the longer the better for some freaky reason) we think that is a super ocean fresh fish. Chromer toads are a turn-on for sure but if they are covered in long tailed lice – it just doesn’t get any better.
Why We Hate ‘Em
It’s really common for most all adult salmon to have sea lice attached to them. But its not so common for fry that are just starting their ocean life phase to be infested. Juvenile salmon or steelhead have thin skin and even one louse can inflict a fatal wound to an immature fish.
Experts have noticed a spike in juvenile fish infestations in recent years. Why now? What is different? Adult salmon and juvenile salmon do not commonly exist in close proximity in the wild. The advent of farmed salmon has changed that. Farmed salmon share the same water as the migratory juvenile salmon and high concentrations of adult salmon are perfect breeding grounds for the nasty parasite. This new habitat change has led to the spike in juvenile infestations, and some experts quote that wild salmon near fish farms are 73% more likely to be infested than salmon not near fish farms.
User groups and experts are very concerned about this data, and this is an especially hot issue for BC. Most all of the fish farmed in BC are Atlantics and if introducing a foreign salmon species to some of the world’s premier wild salmon and steelhead waters is not enough of a problem – Atlantics seem to be fond prey to the little planktonic parasites.
Salmon farming is illegal in the Exclusive Economic Zone in Alaska, but farming salmon is legal in British Columbia. When farming first started in BC, Alaska fishery scientists initially feared farmed Atlantic salmon would escape and compete for food with native Alaska populations of wild salmon. Now the new sea lice connection to fish farms research shows there is a lot more to worry about than just escapement.
It does not take a marine biologist to deduce that farming fish near populations of wild salmon is a bad idea if you value wild salmon. Many conservation groups are trying to educate people to this issue – the Native Fish Society to name only one. We think you should know what kind of salmon you are eating and think twice about eating farmed salmon.
And that’s that. Sea lice may be tiny little critters but they’re big friends and big enemies, both at the same time.
Originally published here.