DEPOMOD & AutoDEPOMOD: Models changing aquaculture planning practices in Scotland and worldwide
Submitting InstitutionUniversity of the Highlands & Islands
Unit of AssessmentEarth Systems and Environmental Sciences
Summary Impact TypeEnvironmental
Research Subject Area(s)
Biological Sciences: Genetics
Agricultural and Veterinary Sciences: Fisheries Sciences
Summary of the impact
DEPOMOD, and AutoDEPOMOD, are models, developed by Prof. Black's research
team, which predict the impact of fish-farm discharges on the seabed in
order to optimise the operation of aquaculture sites to match the
environmental capacity. Since being adopted by the Scottish Environment
Protection Agency, AutoDEPOMOD now forms a compulsory stage in the
aquaculture planning consent process in Scotland, and has been used in the
development of all presently operational salmon sites in Scotland. DEPOMOD
and AutoDEPOMOD software have 122 licences in 25 countries worldwide.
Fish-farms discharge waste (fish faeces, food waste and chemical
treatments) accumulates on the seabed causing organic enrichment which can
lead to conditions toxic to marine life. The Scottish Environment
Protection Agency (SEPA) monitors and regulates aquaculture discharges and
specifies Environmental Quality Standards (EQS) for sea-floor sediments
which are enforced for all aquaculture sites in Scotland.
Predicting how discharge levels will impact seabed environmental quality
in order to plan new, or for expansion to existing, aquaculture operations
is difficult due to the complex site-specific predictive modelling
For >20 years UHI researchers (Black, Nickell, Cromey) have studied
the aquaculture — marine environment interaction, investigating
aquaculture pollution, disease and parasite management and recovery
processes in fish-farm sediments. In 1998, Prof. Black's research team
began a 2 year project to model how fish-farm waste settles on the seabed.
The project developed a model, named DEPOMOD, which took into account site
specific conditions such as current speed, water depth, fish biomass and
feed volume to predict discharge amount and deposition area. DEPOMOD was
the first aquaculture discharge model which could be accurately adapted
for individual sites. The project steering committee comprised SEPA and
representatives from the aquaculture industry including the Scottish
Salmon Growers Association (now SSPO). SEPA recognised the development of
the model as a means to accurately predict effects on the seabed below
fish-farms. In 2001 SEPA supported further development of the model by the
research team to examine the discharge of sea-lice medicine from fish-farm
sites in order to derive appropriate limiting license conditions for
DEPOMOD has since been adapted to aquaculture practices in other parts of
the world: from 1999-2003 the UHI research team led an EU consortium to
develop MERAMOD for Mediterranean fish-farms to model the predicted
deposition of particulate waste faeces and feed from sea bass and bream
farms. Prof. Black (UHI) also led the development of TROPOMOD (2006-2008)
to analyse the environmental impact of aquaculture in the Philippines. The
model assesses the impact of milkfish and tilapia, the two most important
fish cultured in the Philippines.
DEPOMOD provided accurate prediction of fish-farm waste deposition and
impact to the seabed, however the functionality of the model was limited
as any changes to specific parameters meant all parameters had to be
re-set. Since 2001 work has been on-going to enable the user to change
individual parameters within a live model. This development, named
AUTODEPOMOD, increased the use of the model to enable it to be used in
optimising fish-farm capacity. AUTODEPOMOD allows individual parameters
(such as biomass) to be changed until the modelled discharge level reaches
the EQS set by SEPA, thereby advising the optimum fish farm capacity
within environmental limits.
In 2005 AUTODEPOMOD was adopted by SEPA as a compulsory step in the
planning process for new and expanding aquaculture sites. Prof. Black and
his team continue to work to improve the model and are currently
integrating sulphur chemistry into AutoDEPOMOD and have been commissioned
by the Scottish Government to re-parameterize and recode AutoDEPOMOD.
References to the research
1. Cromey, C.J., Black, K.D., Edwards, A. and Jack I.A. (1998)
Modelling the deposition and biological effects of organic carbon from
marine sewage discharges. Estuarine Coastal and Shelf Science, 47, 295-308
(IF 2.247, 5IF 2.622,19 citations)
2. Cromey, C. J., Nickell, T. D. & Black, K. D. (2002).
DEPOMOD — modelling the deposition and biological effects of waste solids
from marine cage farms. Aquaculture 214, 211-239. (IF 2.041, 5IF 2.696,
3. Cromey, C. J., Nickell, T. D., Black, K. D., Provost, P. G.
& Griffiths, C. R. (2002). Validation of a fish farm waste
resuspension model by use of a particulate tracer discharged from a point
source in a coastal environment. Estuaries 25, 916-929 (IF 2.109, 35
4. Cromey, C.J., Nickell, T.D., Treasurer, J., Black, K.D.,
Inall, M., (2009). Modelling the impact of cod (Gadus morhua L)
farming in the marine environment-CODMOD. Aquaculture 289, 42-53. (IF
2.041, 5IF 2.696, 7 citations)
5. Dean, R. J., Shimmield, T. M. and Black, K. D. (2007). Copper,
zinc and cadmium in marine cage fish farm sediments: an extensive survey.
Environmental Pollution 145, 84-95. (IF 3.746, 5IF 3.987, 30 citations)
6. Cromey, C.J., Thetmeyer, H., Lampadariou, N., Black, K.D.,
Kögeler, J., Karakassis, I., (2012). MERAMOD — predicting the deposition
and benthic impact of aquaculture in the Eastern Mediterranean.
Aquaculture Environment Interactions. 2, 157-176 (IF 2.2 , 0 citations)
Key grant-funded projects:
• DEPOMOD, the original modelling project, supported also by SEPA
and Marine Harvest: NERC LINK (1997), £127,647
• Meramed provided the opportunity to develop MERAMOD at Greek
fish farms: EU FP5 (1999), £177,300
• DEPOMOD developed the model to predict medicine residues in
sediments: SEPA (1999), £9,703
• ECASA tested the model at a range of European sites (www.ecasatoolbox.org.uk):
EU FP6 (2004), £1,657,504
• Depobiomass developed a new front-end to allow iterative
operation: AutoDEPOMOD: SEPA (2004), £12,268
• Cod Environment developed the model for application at cod
farms: SEAFISH/CEC/HIE (2005), £178,909
• Philmanaq developed the model for operation in the Philippines:
EU FP6 (2005), £92,478
• Benthic recovery added a diagenetic model based on sulphur
cycling to predict seabed recovery: SARF (2007), £149,498
• Large Sites developed code to allow model-derived spatially
varying currents at large sites: SSPO (2008), £88,015
• Sulphides extended the Benthic recovery project to further
develop carbon diagenesis and predict sulphide concentrations in
sediments: SARF (2012), £99,922
• New AutoDEPOMOD addresses perceived weaknesses in the model's
resuspension processes and recodes the model in Java and ensures platform
and third party software independence: Scottish Govt EFF (2012), £576,400
Details of the impact
Scottish aquaculture is a major industry with an estimated value of
£584.7 million (2011). Scotland is also the largest producer of farmed
salmon in the EU. Where adequate regulation is absent, aquaculture can
have a detrimental environmental impact, affecting not only the marine
environment but the overall sustainability and performance of a site.
Discharges are a primary environmental concern when it comes to planning
or expanding sites. Determining appropriate limits for discharges has been
a difficult task for environmental regulators, because they lacked a
reliable model to accurately predict the impact on the local ecosystem. In
Scotland, SEPA are responsible for the monitoring and regulation of
aquaculture sites, enforcing environmental quality standards for sea-floor
sediment at all aquaculture sites.
Prior to the work of Prof. Black's team in the development of DEPOMOD,
SEPA used a simple empirical matrix as the main planning tool for consent.
This matrix could not optimize farms to their environmental surroundings,
creating a `trial and error' approach to finding the optimum farm size,
leading many farms to close due to pollution problems4,5.
Research by Prof. Black's team (1998-2000) saw the development of DEPOMOD.
As part of the original steering committee, SEPA realized this model could
provide a means to apply scientific rigor to their aquaculture planning
process and enable plans to be optimized to the site-specific conditions.
SEPA supported the work of Black and his team to further develop and
streamline DEPOMOD leading to the development in 2005 of AutoDEPOMOD4,5.
AutoDEPOMOD has the capability to automatically iterate towards a solution
which will optimise productivity whilst remaining within Environmental
In 2005 AutoDEPOMOD was adopted by SEPA as a compulsory stage in the
planning process. Since 2005 (and continuing), any operator wanting to
develop a new aquaculture site or expand an existing one must use
AutoDEPOMOD to identify the sustainable size for a proposed farm4,5.
All presently operational salmon sites in Scotland have used AutoDEPOMOD,
enabling site developers to accurately match farm size to the capacity of
the environment providing the industry with a streamlined process to
enable farm optimisation from the outset whilst ensuring environmental
standards are maintained.
AutoDEPOMOD continues to be a compulsory stage in the aquaculture
planning process and Prof. Black and his team continue to work with SEPA
and aquaculture industry representatives, including the Scottish Salmon
Company6 and Marine Harvest7 to update the model to
support future industry developments. The research team have been awarded
a grant of £576,400 from the Scottish Government (2012-2014) to recode
AutoDEPOMOD and to improve the modelling of resuspension processes.
- The DEPOMOD model developed by Black and his team has international
presence within the aquaculture arena. At present, 122 DEPOMOD licence
holders exist in 25 countries, 26 of which have been issued in the
period 2008-2013, including 21 commercial licences and 5 non-commercial
licences1. In 2012 the Canadian Department of Fisheries and
Oceans requested DEPOMOD to regulate the aquaculture industry and was
used to predict benthic impacts at new and proposed Salmon farms in
Southwestern New Brunswick (2009, 2012)8.
- Black led the development of DEPOMOD for specific regions including
the Mediterranean (MERAMOD) and Philippines (TREPOMOD). At present, 25
licence holders of MERAMOD and TREPOMOD exist, 11 of which have been
issued since 20081.
- The development of AutoDEPOMOD means that a greater level of
confidence can be applied to measuring the sustainability of a fish-farm
at any given site. In 2010 SEPA Aquaculture Specialist commented to NERC
(funders of the original DEPOMOD project 1998-2000): "The development
of DEPOMOD and subsequently AutoDEPOMOD as tools to be used in the
regulatory process has significantly improved the means by which SEPA
assesses the size of fish farm which can be sustained at any given
site and has provided an increased level of scientific rigour in
defining local environmental capacity"2,5.
- In recognition of his international reputation in aquaculture
environment impact research and development of DEPOMOD, Prof. Black
(UHI) became a member of the Scottish Government Working Group on
Aquaculture8as an expert in aquaculture environment impacts
- AutoDEPOMOD has facilitated a positive impact to the natural
environment by placing environmental health at the centre of aquaculture
planning. Since AutoDEPOMOD has been implemented in Scottish aquaculture
planning, farms have been re-scaled to match local environmental
capacity and many former polluted sites are no longer used. Overall,
Scottish aquaculture now has, and continues to have, a relatively lower
seabed impact than pre-2005 due to better planning through AutoDEPOMOD4,5,6,7.
Sources to corroborate the impact
- The Head of IT at SAMS, controls licence distribution for DEPOMOD and
AutoDEPOMOD and provides support to licence holders. Steve can
corroborate licence distribution figures and provide further details
- In 2010, the Natural Environment Research Council (NERC) published an
Impact Statement detailing the research and impact of DEPOMOD. This case
study provides an overview of the scientific research, the funding
inputs, research partners, industry collaborations and the resulting
socio-economic impacts. The case study also provides comment from an
Aquaculture Specialist at SEPA. http://www.nerc.ac.uk/business/casestudies/documents/scottish-ing.pdf
- PHILMINAQ: mitigating impact from aquaculture in the Philippines. This
project developed Depomod for the Philippines. Here is an independent
account of that project: http://www.gefcoral.org/LinkClick.aspx?fileticket=T79qyZpH-cs%3D&tabid=3260
- Head of Operations (North), SEPA — a key figure representing Scottish
Government in terms of the Ministerial Working Group on Aquaculture and
driving the SEPA approach to fish farm regulation.
- Aquaculture Specialist, SEPA — the key fish farm regulator in Scotland
who is intimately associated with the application and development of
DEPOMOD to the Scottish fish farming industry.
- Environmental Manager, Scottish Salmon Company — can provide insight
into the direct impact that DEPOMOD makes on the business environment in
the fish farming sector, from the point of view of a large enterprise.
- Representative of Marine Harvest — This individual will be able to
give an insight into the direct impact that DEPOMOD makes on the
business environment in the fish farming sector from the point of view
of a multi-national company, Scotland's largest fish farmer.
- DEPOMOD is used by the Department for Fisheries and Oceans of Canada
to regulate aquaculture activities in the region. Evidence of the use of
DEPOMOD by the Canadian Authorities can be found: http://www.dfo-mpo.gc.ca/csas-sccs/Publications/ScR-RS/2012/2012_035-eng.pdf
- More information about DEPOMOD and DEPOMOD projects can be found on
the UHI webpages at http://www.sams.ac.uk/kenny-black