Predicting benthic chemistry around marine fish farms

The size of marine fish farms is determined to a large extent by the scale and degree of the impacts of uneaten food and of fish faeces falling to the seabed. This causes changes in the chemistry and biology of the seabed. If the size of the farm is not well fitted to the environment in which it is sited, the seabed can become polluted to the extent that seabed worms are killed and the capacity of the sediment to process wastes is impaired - this can be accompanied by reductions in oxygen and the release of hydrogen sulphide, both of which are harmful to farmed fish.

A vastly upgraded version on the existing globally dominant model for predicting these effects will shortly be completed, funded by the Scottish Government (called New DEPOMOD). We propose to address 3 novel problems by using this model: 1) including in the model results from a recent study of current acceleration under cages which can enhance erosion thereby reducing effects on the seabed in some circumstances; 2) by adding a sub-model that can simulate the degradation of wastes on the seabed by microbes, the model will be capable of predicting a directly measureable chemical endpoint in sediments and; 3) working with the regulator (the Scottish Environment Protection Agency - SEPA) we will use multiple instances of the model driven by a seprate model of the water currents in a particular areas having several fish farms to assess the cumulative effects of synchronous medication with in-feed sea lice medicines.

These tasks will deliver: 1) improved predictive abilities at the more exposed sites of the type that the global marine fish farming industry is increasingly exploiting; 2) the world's first integrated fish farm benthic impacts model with measurable chemical endpoints and 3) the first modelling assessments of the fate of cumulative pesticide release within water-bodies containing several fish farms - leading to an assessment of the appropriateness of present environmental regulations. Collectively, this work represents a significant step forwards in our ability to predict the capacity of the environment to deal with fish farm wastes on the seabed in the context of a rapidly expanding industry.

The size of marine fish farms is determined to a large extent by the scale and degree of the benthic impacts for the release of organic matter. A vastly upgraded version on the existing globally dominant model for predicting seabed impacts will shortly be completed, funded by the Scottish Government (New DEPOMOD). We propose to address 3 novel problems by adapting and applying this model in three ways: 1) developing the model to account for a recent study of current acceleration under cages which can enhance erosion under certain circumstances at dispersive sites; 2) by adding an early-diagenesis module so it will be capable of predicting a directly measureable chemical endpoint in sediments and; 3) working with the regulator (the Scottish Environment Protection Agency - SEPA) we will use multiple instances of the model driven by a hydrodynamic model (FVCOM) to assess the cumulative effects of synchronous medication with in-feed sea lice medicines from multiple farms sharing water-bodies. These tasks will deliver: 1) improved predictive abilities at the more dispersive sites of the type that the global marine fish farming industry is typically expanding into; 2) the world's first integrated fish farm benthic impacts model with measurable biogeochemical endpoints and 3) the first modelling assessments of the fate of cumulative arthropocide release within water-bodies containing several fish farms - leading to an assessment of the appropriateness of present environmental regulations. Collectively, this work represents a significant step forwards in our ability to predict benthic assimilative capacity in the context of a rapidly expanding industry.

In the UK the beneficiary will by the Scottish Environmental Protection Agency SEPA whose task it is to regulate the Scottish fish farm industry the other main beneficiary. SEPA have been intimately associated with this work since its inception in the late 1990s when they were part of the steering group of the original project and a co-sponsor (via SNIFFER). They are the main beneficiaries of the Scottish Government funded project to recode DEPOMOD which the present proposal is the immediate successor of. SEPA have indicated a preference for an open-source software licencing agreement as the means to propagate New DEPOMOD and this essentially means that all new code which adds to or changes New DEPOMOD will a) have to be reported to SAMS and b) will have to be also made open source and this includes the present proposal.
The present proposal is supported by SEPA and is the consequence of discussion of how their priorities match with the priorities and conditions of this funding opportunity. In addition, SAMS collaborates with aquaculture regulators in other countries (especially Canada, USA, New Zealand and increasingly Chile) and will also be working with them to use the outputs of the project to influence policy and regulation.
We will form a project advisory group containing policy and science experts from Scottish Government, SEPA and the Crown Estate, as well as from Industry, to guide the work and ensure that it has maximum presence and impact with the industry. To that end we will establish a line of communication between the project and the CEO of the Scottish Aquaculture Innovation Centre (SAIC). We will also continue to engage with CEFAS to ensure that they are kept up to date on model developments as they might interact with their ambitions to grow marine fin-fish aquaculture businesses in other areas of the UK.
We will maintain a website for the project. We will link this to the open-source user community platform that we expect to launch in the spring of 2015 and which we anticipate will form the hub of an existing but presently diffuse network of DEPOMOD users. We will additionally be contacting the entire global community who presently licence the existing DEPOMOD (about 140 licences) and bringing present and proposed model developments to their attention. We will of course continue with the usual routes of communication including articles in trade journals, presentations at aquaculture meetings (e.g. Aquaculture Europe 2016, Edinburgh) and at other marine science meetings including the MASTS 2015 conference and the Challenger Society conference 2016. And of course peer-reviewed papers.
The PI has long and successful experience of engagement with society regarding aquaculture impacts - from hosting public meetings to presenting comment in online media (e.g. The Conversation). He will work with the other participants in the proposed work to ensure that they get opportunities to develop skills in social and business engagement during the course of the project. As appropriate to their present experience and talents, he will encourage them to participate in the several training opportunities for public engagement training that are likely to be available during the course of the research.
The advisory group will meet on a 6 monthly basis and will review inter alia progress towards impact in the light of their experience of the demands and requirements of the sector. We will also seek the advice of key international stakeholders during the course of the project regarding the management of information flow from the project to the international user community. These will include regulators from Department of Fisheries and Oceans (DFO), Canada; the National Oceanic and Atmospheric Administration (NOAA) in the USA and Marlborough District Council (MDC) and National Institute of Water and Atmospheric Research (NIWA) in New Zealand.