The parasitic lice that afflict the salmon have been affecting its production since it was first detected in Norway over half a century ago. And an unlikely savior could be the lumpsuckers, a bulbous little cute looking fish that are themselves favored for their delicacy. Their roe is also a tasty and inexpensive alternative to the caviar. But their greatest use could be as pest managers for the salmons as they are experts at killing the parasitic sea lice.
The lumpsuckers were first used over a decade back in 2009 by a salmon farm in Norway, the Kvaroy Fiskeoppdrett. They have now become an indispensable tool for salmon farming and have supplemented the wrasse fish. They belong to the Cyclopterus lumpus family.
The sea lice are small crustaceans and attach to the fins, skin, and gills of the salmon and feast on their blood, tissues, and mucus all their lives. The open wounds can cause other diseases to affect the salmon and lead to their death. Such infestations are harmful even to the environment and pesticides cannot eliminate them.
Researchers are now relying on other fish to clean the lice from the skin of the salmon and the lumpsuckers are the most promising of the types used. The females can grow up to 24 inches (64 centimeters) though they are generally smaller. The Pacific spiny lumpsuckers grow to an average of 2.5 centimeters.
Farms lose around $350 million every year, according to data from the Sea Lice Research Center at Bergen University in Norway. Though they afflict the wild salmon population in isolation, they proliferate in salmon farms where the fish are densely packed. The lice are not harmful to humans, but the farm salmons can affect the wild population near the farms.
Climate changes and the accompanying increase in water temperatures in the oceans have further aggravated the afflictions. It has disrupted production and has forced the salmon farms to divert valuable resources to fight the parasitic lice infection.
Lumpsuckers Score Over Other Conventional Methods Like Medicines
Past attempts to fight the lice with medicinal treatment have resulted in the sea lice developing drug resistance. And with the pressure to shift to additionally sustainable methods, the lumpsuckers appear to be the best option. Some regulations restrict the lice that can be found on farms where they are forced to harvest or treat the salmon to reduce the impact on the environment.
Cleaner fishes like the lumpsuckers are the best alternative to bring down the level of lice on the farms. An incredible 60M cleaner fish like the lumpsuckers are used in farms around the world, and there are growing demands for them. While both the Ballan wrasse (Labrus Bergylta) and the lumpsuckers are useful. But the lumpsuckers are better adapted to colder waters during winter and autumn.
The cleaner fish varieties like the lumpsuckers are let loose into the salmon pens once they are big enough. There are cleaning stations and special refuges where the fishes begin the process of cleaning. Mowi, the largest salmon-producing farm has said that the cleaner fish are very effective. the company took over a facility for the production of cleaner fish in 2018 to take care of their salmon population in farms in Norway and Chile.
The environmentally friendly process of using cleaner fish varieties like the lumpsuckers and the Ballan wrasse has been effective and popular. Other processes used include spraying water streams to dislodge the lice, land other mechanisms to drive the salmon to deep water that saves them from lice close to the surface.
As the lumpfish do not find any mass takers, concerns have been raised on the ethics of wasting such a large number of fish. They are now being turned into fish meals for other farmed species of fish. But more research is needed to ensure better use of the lumpsuckers and other varieties of cleaner fish that will help reduce dependence on medicines.