Use of wrasse and other non- pharma methods against sea lice · How do “Labrus wrasse” work as cleaner fish (1 st year growers)? › > 300 000 wrasse put to sea 2012 in sites

Use of wrasse and other non-pharma methods against sea lice

Olav Breck MHG

SLRC seminar lice, Bergen, September 2013

Pyr

Salmosan

Slice

Combinations

H2O2

Cleanerfish

>14C resistance?

Alternative methods ??????????????

SLAUGTHER

Why focus on non-medicinal approaches

How avoid?

• optimal use of existing compounds/tools• new drugs • cleanerfish where possible• work with alternative non-pharma solutions

Non- medicinal approaches to control lice

3

› Scotland 1990’s: cases from field with 7.5 % effect of H2O2 after 20 min with 2000 ppm

› Trial showing 15-25% effect on “farm lice” versus 87-99% on naive lice

› Genetic selection for increased detoxification(catalase..) or reduced carapace (exoskeleton) permeability

› H2O2 resistance seen in bacteria

› Field observations Norway 2012 with suspicion of reduced effect

› Recent cases with indications of reduced sensitivity

› Lab studies to verify and look at heritability in planning

Is resistance to H 202 possible ?Non- medicinal approaches to

control lice

Prevent lice getting close to salmon

• Skirts• Bubble wall• Electrical fence

Preventing salmon getting close to lice

• Use of lights• Deep water feeding• Submerged farming

• “Snorkel”• Diving bell • Periodic access

to surface

Non-pharma removal

• Cleaner fish• Mechanical • Warm water • Optical delousing Laser• Anti – attachment diets

roof

surface


Cleanerfish the only non-pharma method controlling li ce today Cleanerfish the only non-pharma method controlling li ce today

USE OF CLEANER FISH

› Production of Ballan wrasse at Marine Harvest Labrus

• background

• biology and fish health

› How do “Labrus wrasse” work as cleanerfish ?

› How do lumpsucker work as cleanerfish?

› New species, “new” diseases.

› Considerations on welfare and ethics

› Our strategy Photo: Ø. Vågnes

Cleanerfish

Production of Ballan wrasse at MH Labrus

› Why Ballan wrasse ?• more robust /active during winter • more efficient with large salmon • lower numbers from wild catch

› First and currently only commercial wrasse rearing site, established in Øygarden, west of Bergen, spring 2009 (cod productions facilities, with experienced staff)

› Intake of wild caught Ballan wrasse › Co-operation with wrasse project in MHSc› Recently MHN has purchased an on-growing facility in MHN Mid› Renting on-growing facility south of Bergen from August 2013

Cleanerfish

7

Production cycle

12 months

Cleanerfish

Biology and fish health

› Currently running 3 broodfish populations based on artificial photoperiods › Successful and reproducible production of high numbers of larvae, but challenges..

› Rearing/biology • big variation in survival between groups from start feeding to weaned fish (5 - 20%)• slow growth from 2gr• aggression, tail biting• clumping behavior

› Nutrition • short digestive tract, need easily digestible feed (soft pellets)• weaning feed not optimized, can give deformities if used too long• picky eaters, feed needs to be tasty (high shrimp or krill content)

› Health• fin rot• deformities (head/jaw, spinal)

Several projects running and planned to address bot h health and nutritional issuesSeveral projects running and planned to address bot h health and nutritional issues

Cleanerfish

How do “Labrus wrasse” work as cleaner fish(1st year growers)?

› > 300 000 wrasse put to sea 2012 in sites with smolt (S1, S0)› Trials comparing farmed with wild caught;

• effect on lice good! (comparable to wild caught) › Early delivery a major advantage

Weekly lice numbers

S0 12 G, stocking 3% wrasse autumn 2012. “at least 2 chemical treatments avoided”

Cage Week delivered

1,3,6 30

2,4,5, 24

Cleanerfish

How do “Labrus wrasse” work as cleaner fish(2nd year growers)?

› Farmed and wild caught wrasse do the job first year in sea› Challenges often related to sea lice control 2nd year in sea› Planned testing of own produced large wrasse summer and autumn 2013

(effect of different sizes and numbers stocked)› AGD at MHL � legal restrictions and delayed transfer

› Only one farm currently holding large “Labrus wrasse”; (12G)

› Ca. 25 000 wrasse, size 70-80 g› Transfer wks 30, 31 and 36› 2-3 % stocking per cage

› 2-3 mores sites in MHN South to stock large “Labrus wrasse” autumn 13

10

Cleanerfish

How do lumpsucker work as cleaner fish?

› Known to have cleanerfish ability for several years (GIFAS report, 2000)› Relatively easy to rear (no live feed period), with short production cycle

› Although lack of well designed field tests so far, or low lice pressure, several observations from field (MH and externally) indicate that lumpsucker in periods control lice

› Farmers report that winter treatments against lice avoided

› Improved disease situation 2013 (Vibiosis, atyp. Furunc,)

› Controlled trials now running › Vaccine development

We might have 2 winners; Ballan wrasse when no too cold and lumpsucker when n ot too warm

We might have 2 winners; Ballan wrasse when no too cold and lumpsucker when n ot too warm

Cleanerfish

New species, “new” diseases.

› AGD

• Paramoeba perurans found in wild caught wrasse

• AGD outbreaks at IMR research station and MHLabrus

• No effective control by H2O2, but brackish water, 15 ppt, for 7 d, 100% clearanc e

› Nodavirus

• Betanodavirus found in wild caught wrasse (Persson and Røsæg 2013)

• Found in brain tissue

• Phylogenetic studies - identical to betanodavirus described in Atlantic cod

• Ballan wrasse as a natural host for betanodavirus ?

• Ability to cause disease in Ballan wrasse ?

• A low risk to salmon via waterborne transmission (Persson and Røsæg 2013)

• Nodavirus found in a variety of other marine fish species

Cleanerfish

New species, “new” diseases

› IPNV and PRV• Detected in gill tissue from wrasse cohabitating with Atlantic salmon

(Persson and Røsæg 2013)• Wrasse have the potential to function as mechanical vector

› VHSV• Wrasse found positive at a seawater hatchery in the Shetland Isles• Population culled

› SAV• Trials running to see if wrasse a biological vector

CAN THE AGENTS CAUSE DISEASE IN CLEANERFISH ?ARE WILD STOCKS OF WRASSE OR LUMPSUCKER AT RISK?DOES CARRIER STATE REPRESENT A THREAT TO FARMED SAL MON?

POSITIVE FINDINGS MIGHT IMPOSE RESTICTIONS ON OUR FARMSPOSITIVE FINDINGS MIGHT IMPOSE RESTICTIONS ON OUR FARMS

Cleanerfish

Considerations on welfare and ethics

› Increased focus on welfare of cleanerfish, incl. from customers› Some 10 mill cleaner fish used per year - no reuse› Various causes for losses during SW period, but only partly known › Registration of mortalities, but investigations on etiology should be improved

› Welfare to be ensured through;• feeding of cleanerfish• proper hiding places• removal of bad doers• health monitoring, vaccination • …

› Projects running to increase survival during winter time and revealcauses of mortalities

› Autumn 2013: NRC funding with focus on cleanerfish welfare

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Cleaner fish

Our strategy

› Address biological, nutritional and health challenges in rearing of Ballan wrasse

› Gain more field experiences with use of lumpsuckers and (large) Ballan wrasse

› Optimize use of cleanerfish

› Ensure cleanerfish health and welfare

› Review risk and legislative scenarios related to “new” diseases in cleanerfish and initiate adequate research

CLEANERFISH THE ONLY EFFECTIVE NON-PHARMA METHOD WO RKING TODAYCLEANERFISH THE ONLY EFFECTIVE NON-PHARMA METHOD WO RKING TODAY

Cleaner fish

Submerged farming - “snorkel concept”

› Concept• IMR has shown that fish can be kept submerged for weeks, but eventually, empty

swim bladder leads to various problems (increased swimming speed, tilting, compressions of spine, deformed vertebra)

• How to provide air ? Diving bell, periodic removal of roof or › central snorkel

› Status• First trial by IMR (12x12 m, 3 m snorkel, 3 months)

Reduced lice infestation by 66 - 84%However 30% reduced growth ! (fed through roof..)

• Second trial (growth focus)Trend of 10% growth reduction (n.s.)Nose woundsSub-optimal refilling of air-bladder

› Future plans• In autumn IMR to run trial with up-scaled version with large salmon

Roof

surface

Frode Oppedal, IMR


17

Trial with snorkel concept at IMR Matre


Global R&D-seminar, Bergen 10-11 September 2013

Large scale trial with snorkel MHN North 2012/13

18


Submerged farming - deep water feeding +/- submerged light

› Concept• Sea lice larvae phototactic and moves towards light

› In fjord system lice under halocline

• Literature show effect on lice by keeping fish below “lice layer”. Could this be achieved by;› Submerged feeding during day time› Submerged light during night that prevents fish from

seeking to surface

› Status• Trials at MHN site Bastlid:

› deep water feeding keeps fish down during day time

• Trials MH Scotland (with UoStirling) summer 12;› Positive effect on lice levels by of submerged light› Effect of submerged feeding ?

› Future plans• A promising concept – should be followed up

Hevrøy et al 2003; Huse and Holm, 199?; Oppedal et al 2011

daytimenighttime


AQUA GENBREEDING

SALMOBREEDBREEDING

SFD, electric fence

GLAXUS mussels

FJORD FORSKSOGN

mussels

BOLAKS (Freshwater)

BOTNGÅRDperma skirt

CALANUS Plancton net

AKVAFUTUREEnclosed

tarp

CLEANER FISH

KYST INKUBATOR (Freshwater)

Summary sea lice meeting March 4 2013When do the industry actors believe they have a solution on the market?

Documents

Use of wrasse and other non- pharma methods against sea lice · How do “Labrus wrasse” work as cleaner fish (1 st year growers)? › > 300 000 wrasse put to sea 2012 in sites