The global salmon farming business has been struggling since it was founded in the 1970s to control the severe economic, animal welfare, and ecological effects of sea lice infestation, which has kept salmon farming from reaching its full potential. Currently, the year has been put up as estimates for the economic impact of between USD 400 and USD 600 million (EUR 366 million to EUR 549 million). However, solving the problem can harm marine ecosystems, and lice can develop resistance to treatments.

Salmon farms constantly struggle against the onslaught of sea lice (Lepeophtheirus salmonis, Caligus rogercresseyi, etc), it is also a real challenge for parasitologists to solve this huge problem that has continued to build up over the years since the start of salmon aquaculture. While the ability to deal with sea lice outbreaks is often the most pressing concern of those involved in salmon production, there is an acknowledgement that the use of long-term integrated strategies for managing them is an important consideration to the industry's sustainability.

Sea lice infestation

The ectoparasite attaches to the body surface of Salmon fish, the attachment is typically near the base of the fins or on the body surface.

While they feed on their host, they remain too small to cause significant harm. However, as they mature into more mobile pre-adult and adult stages, there is a shift in their attachment method to suction, making them more lethal.

They mostly feed on host mucus, skin, and underlying tissue.

Life cycle of sea lice

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Symptoms

·Serious damage to the skin

·Inflammation and Redness

·Fins Erosion

·Fatigue

·Reduced Appetite

Recent Sea Lice Management Methods (Image)

Prevention

1. Functional feed:

Feed that contains ingredients that thicken the mucus layer, promote healing or repel copepods

1. Sea lice trap:

Traps are placed around the pens which attract sea lice away from salmon using light and odorant

1. Deep lights/feeding:

Salmon are attracted to depths without sea lice with light or feed.

1. Sea lice skirts:

A fabric that covers the top of the net prevents sea lice larvae from entering the sea pens.

Treatment

1. Cleaner fish:

Cleaner fish are housed in the same sea pens as salmon and eat sea lice that are on the salmon

1. Hydrogen peroxide:

Infected salmon are exposed to hydrogen peroxide at concentrations that kill sea lice

1. Chemotherapeutics:

Infected salmon are exposed to chemicals via baths or feed

1. Mechanical:

Salmon are pumped through water jets. Sea lice are dislodged

Norwegian Standards for Mean Sea Lice/ Fish

In Norway, strict regulations are in place to control sea lice levels in salmon farms to protect wild and farmed salmon populations. The Norwegian standards for the mean number of adult female sea lice per fish are as follows:

Threshold Levels

1. Southern Norway:

1. During the critical weeks of 15 to 21 (spring smolt migration), the limit is 0.2 adult female sea lice per fish.
2. For the rest of the year, the threshold is 0.5 adult female sea lice per fish.

2. Northern Norway:

1. A uniform limit of 0.5 adult female sea lice per fish is maintained year-round

Also, in 2017, the government introduced a new category of “green permits,” which required sea-lice levels of between 0.25 and zero, and the demonstration of a new production method or equipment that would reduce sea-lice and/or escapement. Farms exceeding these limits must take immediate measures, such as delousing treatments.

Effects of the Residues between Plant-derived Compounds and Chemical Treatments

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HERE’S HOW WE ARE RECLAIMING THE BLUE...

Many studies have shown that essential oils, extracts, and isolated substances from plants might be an important and alternative oral and immersion treatment against parasites in aquaculture. These plant extracts are capable of enhancing immune responses and disease resistance of cultured fish, serving as great phytotherapeutics against infections in aquaculture.

CRUSTAXE is a synergistic combination of plant-derived semiochemicals that precisely target the planktonic copepod crustaceans by avoiding all the unintended negative effects on the ecosystem. It can be incorporated into the functional feeds as a feed additive to repel the copepods. The bioactive present in ‘CRUSTAXE’, even at very low concentrations, can interfere with the host location and disrupt copepodid settlement on salmonid fish.

HOW DOES CRUSTAXE WORK?

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Benefits

1. Environment friendly
2. Suits consumer food safety requirements
3. Non-medical natural solution
4. Minimize dependence on chemotherapeutic
5. No bioaccumulation

“A sustainable initiative to manage sea lice challenges”