Improved parasite control in the global Atlantic salmon farming industry
Submitting Institution
University of StirlingUnit of Assessment
Agriculture, Veterinary and Food ScienceSummary Impact Type
EnvironmentalResearch Subject Area(s)
Biological Sciences: Genetics
Agricultural and Veterinary Sciences: Veterinary Sciences
Medical and Health Sciences: Medical Microbiology
Summary of the impact
Sea lice are the principal disease constraint for world Atlantic salmon
culture and cost >€33m
yearly in the UK and >€305m globally in terms of control measures and
lost production. Research
conducted by the University of Stirling's Institute of Aquaculture (IoA)
has provided tools and
strategies for sea louse control in farmed salmon worldwide. Impacts have
been delivered through
an integrated pest management approach which involves
(1) introduction of management tools including fallowing, single
year-class stocking and area
management
(2) screening, development, licensing and monitoring of veterinary
medicines
(3) development of alternative strategies such as use of cleaner fish
(wrasse) and sea louse
resistant salmon
(4) incorporation of integrated pest management principles into public
policy and legislation.
These tools and approaches are now being used by the U.K. and global
Atlantic salmon industries.
Underpinning research
Sea lice are ectoparasitic copepods causing major economic losses for the
global Atlantic salmon
aquaculture industry. Use of an integrated pest management strategy for
sea lice control was first
proposed by IoA's Professor Christina Sommerville at the Scottish
industry's annual conference in
1994. `Integrated pest management' is a term encompassing the co-ordinated
use of a wide variety
of tools and approaches for the effective management of crop and livestock
pathogens, particularly
to reduce drug resistance development, and this strategy is key to IoA's
underpinning research.
Farm management approaches
Appropriate use of management tools is a critical aspect of integrated
pest management for sea
lice. Industry-funded work at IoA (Ref. 1) was the first to provide
evidence to recommend fallowing
and use of single-year-class stocking policies to assist sea louse control
and to examine the effects
of treatment through a farm cycle. In the late 1990s the use of Area
Management Agreements to
co-ordinate farm management within defined areas was developed from this
research, ensuring
appropriate fallowing after harvesting, synchronisation of treatments
across Farm Management
Areas and use of effective communication strategies. In addition to farm
management approaches,
integrated pest management strategies require the development and
deployment of a wide range
of complementary tools for pest control including use of medicines and
biological controls.
Veterinary medicines
Following development of sea louse drug resistance to the organophosphate
dichlorvos (~1992),
the IoA, through its Marine Environmental Research Laboratory (MERL), has
increasingly played a
central role in the identification, development, licensing, deployment and
monitoring of the vast
majority of medicines used against sea lice worldwide (1993-2013). In
collaboration with industry
(including Pfizer, MSD Animal Health, Novartis, Solvay Interox; feed
companies Skretting
(Nutreco), Ewos and BioMar and producers Marine Harvest), the IoA has
helped to develop
hydrogen peroxide (research from 1993-2013), azamethiphos (from 1993),
teflubenzuron (from
1994-2013), diflubenzuron (from 1996) and the most widely used and
successful medicine to date,
emamectin benzoate (SLICE®, 1993-2013) see Refs 2-4. Research has included
in vitro and in
vivo screening of candidate products, efficacy studies to identify
dose and treatment regimen,
farm-scale trials, regulatory studies to evaluate safety,
pharmacokinetics, metabolism and residue
depletion and bioaccumulation by filter feeders. Work to develop new drugs
is supported by
ecotoxicology risk assessments, environmental impact assessments and
modelling of
environmental concentrations of drugs (Ref. 5) conducted by IoA for
industry and government, and
incorporated into Scottish Environmental Protection Agency (SEPA)
guidelines. Monitoring drug
resistance is central to integrated pest management and IoA has been a
world leader in industry-funded
(Ciba Agriculture, Scottish Salmon Growers' Association Ltd,
Schering-Plough Animal
Health / MSD Animal Health) research to investigate the molecular
mechanisms involved in
reduced susceptibility to drug treatment and techniques to manage
resistance (1993-2013).
Non-chemotherapeutant controls
Since 1993, industry-funded research efforts at IoA have increasingly
included non-chemotherapeutant
control methods including vaccines (£227,372, 1993-2010), functional /
immunostimulant
feeds (£209,057, 2008-2013) and trials to help develop genetically
resistant
salmon stocks. Work conducted with Landcatch Natural Selection (part of
Hendrix Genetics) as
part of a Defra LINK project (2009-2010) demonstrated substantial scope
for the breeding of
resistant salmon (Ref. 6).
Key IoA staff working on sea lice (1993-2013): Professor C
Sommerville, Professor R Richards,
Dr R Wootten, Dr W Roy, Professor J Bron, Dr A Shinn, Dr T Telfer, Dr M
Roth, Dr J Stone,
Professor H Migaud and Dr A Sturm.
References to the research
(Stirling researchers in bold)
1. Bron, J.E., Sommerville, C., Wootten, R. and
Rae, G.H. (1993). Fallowing of marine Atlantic
salmon, Salmo salar L., farms as a method for the control of sea
lice Lepeophtheirus salmonis
(Krøyer, 1837). Journal of Fish Diseases, 16, 487-493.
2. Roth M., Richards R.H., Dobson D.P., Rae G.H. (1996).
Field trials on the efficacy of the
organophosphate azamethiphos for the control of sea lice (Copepoda:
Caligidae) infestations
of farmed Atlantic salmon (Salmo salar). Aquaculture, 140,
217-239.
3. McAndrew K.J. Sommerville C., Wootten R.and Bron
J.E. (1998). The effects of hydrogen
peroxide treatment on different life-cycle stages of the salmon louse, Lepeophtheirus
salmonis
(Krøyer 1837). Journal of Fish Diseases 21(3), 221-228.
4. Stone, J., Sutherland, I., Sommerville, C., Richards,
R.H. and Varma, K.J. (1999) The
efficacy of emamectin benzoate as an oral treatment of sea lice, Lepeophtheirus
salmonis
(Krøyer), infestations in Atlantic salmon, Salmo salar. Journal
of Fish Diseases 22 (4), 261-270.
5. Telfer, T. C., Baird, D. J., McHenery, J. G., Stone,
J., Sutherland, I., and Wislocki, P. (2006).
Environmental effects of the anti-sea lice (Copepoda: Caligidae)
therapeutant emamectin
benzoate under commercial use conditions in the marine environment. Aquaculture,
260(1-4),
163-180.
6. Gharbi, K., Stear, M., Matthews, L. and Bron, J.E. (2011).
LINK project LK0691 final report "An
experimental and modelling framework for breeding Atlantic salmon for
resistance to sea lice"..
Grants for research underpinning impact include:
1. Industry-funded work to develop teflubenzuron, four contracts
1994-1999 £90,000
2. Industry-funded work to develop emamectin benzoate, 19 contracts
1993-2013 £570,864
3. Industry- and government-funded work on drug sensitivity of sea lice,
development of
bioassays and investigation of mechanisms of resistance, 12 contracts
1994-2013 £485,236
4. Defra LINK: The feasibility of breeding Atlantic salmon for resistance
to sea Lice. Professor
Bron, with Professor Stear and Dr Matthews, University of Glasgow,
Dr Gharbi, University of
Edinburgh and Professor Roberts, Landcatch Natural Selection Ltd. £94,419
Details of the impact
Integrated pest management, a concept introduced for sea lice control by
the IoA, is now employed
by all the major cultured salmon producing countries (see the 2013 Sea
Lice Integrated Pest
Management workshop http://aquafeed.com/read-article.php?id=4954).
The impact of IoA's sea
louse research in the REF assessment period 2008-2013 is clearly
demonstrated by
1) industry reliance upon integrated pest management strategies developed
through IoA,
2) increasing levels of industry support and funding for sea lice
research at IoA,
3) sustained growth in the Scottish and global Atlantic salmon
aquaculture industry
4) welfare and economic impact through incorporation of IoA research
findings into industry
codes of practice and the involvement of IoA in formulation of Scottish
Government
policies for farmed fish health and welfare.
IoA sea louse research continues to have major impacts in controlling sea
louse numbers infecting
farmed fish in the UK and globally, reducing economic costs, supporting
sustainability and
protecting fish welfare.
Impacts on fish health and welfare:
IoA research was involved in the development of the majority of
veterinary drugs used to control
sea lice 2008-13. The Technical Director of the Scottish Salmon Producers'
Organisation (which
represents >95% UK producers) has stated that "Work carried out at IoA
has been directly
responsible for providing encouragement and support to international
pharmaceutical companies in
the identification, testing and licensing of new veterinary products for
the treatment of sea lice" and
that "In the course of the past decade, IoA staff have undertaken cutting
edge scientific work that
informs and supports those in the industry responsible for the control of
lice and the welfare of
fish". By facilitating new treatments, particularly emamectin benzoate
(SLICE®), IoA has had a
major impact on the control of sea lice worldwide. MSD (Merck) Animal
Health confirm that,
working with IoA "...we have conducted studies on efficacy and dosing to
support the registration
of Slice throughout the salmon farming world and recently conducted
studies to assess the impact
of the development of tolerance and ways to assess it and combat it."
Impacts on consumer health:
Improved growth and sustainability of the Atlantic salmon industry,
resulting from IoA's impact in
improved sea louse control, has impacts on consumer health by provision of
affordable and
sustainable healthy protein and essential fatty acids. The Managing
Director of Marine Harvest
(Scotland) Ltd. Comments that "loA have increased the sustainability of
salmon farming in rural
communities and reduced environmental impacts through provision of
effective assessment
methodologies and improved consumer health through sustainable healthy
food production as well
as providing various essential services for government and industry."
Impacts on economy and commerce:
Over recent years, the strategy of UK and global salmon aquaculture has
been one of integrated
pest management. As recognised by the Managing Director of Marine Harvest
(Scotland) Ltd. "loA
have contributed to improved economic sustainability of the salmon farming
industry through
development of novel chemotherapeutants, integrated pest management,
selection for genetic
resistance in salmon, involvement in public policy, industry codes of
practice and legislative
development through chairing and membership of national/international
bodies". In summarising
commercial impact, the SSPO states "...IoA has made a significant
contribution towards better
scientific understanding of this commercially important parasite, and that
the application of this
science by industry has, in a number of important respects, been
transformational."
Impact on management practices:
The impact of IoA on management practices is confirmed by the Scottish
Salmon Producers'
Organisation: "The scientific work of the IoA has supported the salmon
farming industry in
developing a range of strategic and practical approaches focused on
minimising impact. Prominent
amongst these approaches is Area Management, which involves separating
year classes within
defined production areas, fallowing after year classes have been
harvested, and synchronising and
coordinating treatment with approved veterinary medicines across
Management Areas. This
approach was first developed in Scotland in the late 1990s on the back of
new science and now
forms the basis of good practice in commercial salmon farming
internationally". This impact is also
endorsed by Paul Wheelhouse, Scottish Minister for Environment and Climate
Change who
confirms "We recognise the value of the University's work to develop
appropriate management
approaches, which include fallowing, single-year class stocking, and the
use of cleanerfish". Use of
Management Areas, fallowing and single-year class stocking are key tenets
in the newest Code of
Good Practice for Scottish Finfish Aquaculture 2013 contributed to by IoA.
Impacts on public policy and services:
IoA research outputs have had considerable impact upon public policy,
industry codes of practice
and new legislation. Richards has roles including SSPO veterinary advisor
and chair of the
Healthier Fish and Shellfish and Farmed Fish Health and Welfare Working
Groups within the
Ministerial Group on Aquaculture. He is facilitator of the Fish Health
thematic area for the EU
Aquaculture Technology Platform and Chair of the National Sea Lice
Platform. Key elements of IoA
integrated pest management strategies and research have led to policy
impact through direct input
into the Code of Good Practice for Scottish Finfish Aquaculture 2013, and
the Aquaculture and
Fisheries (Scotland) Bill 2013 as well as input into the conditions to be
attached to finfish business
authorisations including delivery of single year class stocking of sites,
sea lice treatment and
fallowing of appropriate scale management areas.
Impact demonstrated through industry funding of IoA research:
During the REF assessment period 2008-2013, the IoA had demonstrable and
increasing impact
through industry funding of sea louse research targeting elements of an
integrated pest
management strategy. Over this period, industry funding for IoA and MERL
includes 41 medicine-associated
projects (£1,306,719), seven bioassay/sensitivity/resistance mechanism
associated
projects (£186,767) and eight functional feed associated projects
(£271,340). There are three
current Technology Strategy Board projects. The first of these, 2011-14
"Development of a high-density
salmon SNP chip: a key tool for improving the competitiveness and
sustainability of the UK
salmon farming industry", is a collaboration with Landcatch Natural
Selection Ltd., Affymetrix UK
Ltd., University of Glasgow and University of Edinburgh (£647,339) and
follows from the
underpinning research showing differential genetic resistance to sea lice
in Scottish farmed salmon
families. The first SNP chips produced by this project are now being used
by the industrial partner
to find breeding markers for salmon resistance to sea lice. The second
project "Production and
implementation of farmed wrasse in the Scottish Salmon industry" is a
collaboration with Marine
Harvest Scotland Ltd and Scottish Sea Farms Ltd., having a value of
£2,139,000 for IoA and
MERL, and seeks to provide a sustainable farmed source of wrasse to be
used as biological
controls (cleaner-fish) to remove lice from salmon. Impacts from this
project are already being felt,
with recent introduction of wrasse to a trial site in Scotland cutting
drug treatments from 8x per
farm cycle to none and giving direct savings of 7p per kilo (Scottish
production is >158,000 tonnes
p.a. and growing). The final project leverages IoA's experience in sea
lice and sea louse vaccine
development, being part of TSB's Sustainable Protein call. "Development of
a novel sea louse
vaccine: an environmentally friendly tool for increasing sustainability of
protein production in UK
salmon aquaculture" is an important collaboration with Pfizer (now Zoetis)
and Moredun Research
Institute (total £2,992,000) with impact confirmed by the Head of
Pfizer/Zoetis Business
Development and Global Alliances up to 2013.
Sources to corroborate the impact
- Scottish Government Farmed Fish Health and Welfare Working Group
http://www.scotland.gov.uk/Topics/marine/Fish-Shellfish/MGSA/Farmedfishhealthandwelfarewg
- A Code of Good Practice for Scottish Finfish Aquaculture (Jan 2013)
showing incorporation of
IoA integrated pest management strategies especially section 3.5 Area
management and
Annex 11 National Strategy for Sea Lice Control
http://www.thecodeofgoodpractice.co.uk/publish.
- Scottish Government Healthier Fish and Shellfish website underlining
contribution of Institute of
Aquaculture personnel and research to policy implementation including
"single year class
stocking of sites, sea lice treatment and fallowing of appropriate scale
management areas"
http://www.scotland.gov.uk/Topics/marine/Fish-Shellfish/18364/18610
- Scottish Aquaculture and Fisheries (Scotland) Bill 2013 having direct
input from IoA through
committee Chairs (Professor Richards)
http://www.legislation.gov.uk/asp/2013/7/contents/enacted
- Scottish Sea Farms wrasse video showing impact for industry of
collaboration with IoA and its
Marine Environmental Research Laboratory at Machrihanish
http://www.youtube.com/watch?v=56aQgGpX3Ck
In addition, full written statements from individuals and organisations
quoted above are available.