PRODUCTION

CLEANERFISH
PRODUCTION
Espen Grøtan
Marine Harvest Labrus AS

Use of cleanerfish
• Cleanerfish is commonly used for biological delousing of
salmon in Norway (increasing interest also in the United
Kingdom and Ireland).
• Different species of wrasse is added to the sea cages
(typically between 2 and 5 %). Lumpfish can possible
also be use for this purpose.
• The method is proven efficient, environmentally friendly
and economically beneficial.

Use of cleanerfish
• Sharp upswing the last years as a result of the salmon
industry's resistance problems.
• More than 16 million wild wrasse was delivered to the
salmon farming industry in 2010.
• Reuse is not allowed (one does not know if the wrasse
may act as a vector for transmission of salmon
diseases).
• Transfer of new diseases to salmon is considered not
particularly likely (the species are far apart genetically).

Why farm cleanerfish?
• Wild catch can`t meet the demand alone.
• Development of good practices at salmon farms require
predictability (the correct number of the right quality at
the right time)
• Available all year round (not depending on fishing
season)
• Size of cleanerfish can be adjusted to fit the mesh and
salmon size
• Can be vaccinated and screened for disease before put
to sea
• Avoid injuries and high mortality, which is common in
wild capture
• Reduce the risk of depletion of wild stocks

Production in Norway
• Commercial wrasse production started only 2 years ago:
- Marine Harvest Labrus (2009)
- Profunda (2010)
- Nordland Leppefisk (2010)
- Cleanfish (2011)
• Limited knowledge of the species in aquaculture and of
the biology in general makes production very challenging

Marine Harvest Labrus AS
• Started large scale production of Ballan wrasse in spring
2009
• Uses techniques from cod production with adjustments
• User former cod facility close to Bergen (CCN), which is
very well suited for this purpose
• Aims to supply Marine Harvest Norway with all the
wrasse they need (between 2 and 4 million pr. year)

Marine Harvest Labrus AS
Juvenile production (0,5 gram)

Broodstock
• Ballan wrasse are hermaphrodites (first female, then
male)
• Males are territorial
• Aggression leads to bite injuries, often followed by
infection and death
• Need shelters in the tank
• Soft feed (crushed pellets + shrimp)
• About 20% males in the tanks

Egg collection / incutation
• Benthic and sticky eggs
• Spawning substrates (mats) are placed at the bottom of
the tanks
• Eggs are on incubated at 12 degrees for 7 to 9 days
(attached to the substrates)
• Diameter of eggs are 0.9 mm (salmon: 5.0)
• 1000 000 - 1500 000 eggs per liter (salmon: 5000)

Spawning

Embryo inside the egg

Startfeeding
• The larva is 3.6 mm at hatching
• Very little developed
• First feeding at 4 dph, when the mouth is opened and
the yolk sac is almost gone
• Live feed (rotifers) during the first 4 weeks
• Clay is used for “green water” for about 50 days
• The temperature is raised to 16 degrees

Newly hatched larvae

Weaning
• After about a month the larvae is weaned on to dry feed
• Critical period – if there has been suboptimal conditions
during live feed period (high bacterial pressure, porly
enriched rotaorier) the larvae will not withstand the
transition to dryfeed and die
• Changes the behavior after metamorphosis
- clump together (anti-predator behavior?)
- makes efficient feeding difficult

Larvea 30 dph

Juvenile 45 dph

On growing
• Lice pickers needs to be between 30 and 70 grams (10 –
14 cm)
• In the first 4 cycles we experienced poor growth, high
mortality and deformities after 0,5 grams due to lack of
proper on growing feeds (all commersial feeds failed)
• Better results in cycle nr. 5 when the period using larval
feed was extended, and we started using a feed that has
been developed specially for wrasse

Juveniles 90 dph

Juveniles 90 dph

Juveniles 90 dph

In the sea cages
• Tests performed in tanks on land shows that farmed
Ballan wrasse picks lice from salmon.
• Still little experience from sea cages (first fish from MHL
put to sea in june 2011):
- will they eat lice or will they just go after the waste
feed?
- do they have the ability to pick lice as effective as wild
specimens (vision, maneuverability)?

Main challenges
• The use of spawning substrates provides poor utilization
of the amount of spawned eggs and makes disinfection /
incubation difficult (need methods for stripping?)
• Problematic on growing phase (0,5 grams and up)
- slow growth
- need special feed
- need high temperatures
- clumping makes proper feeding difficult