Science and research

Scientific research includes long term monitoring combined with experimental work and review to understand the processes that drive trends of change in fish populations and fisheries. Advice, based on research conducted at Marine Scotland Science and elsewhere, is provided to the Scottish Government, local managers of fisheries and agencies such as Scottish Natural Heritage (SNH) and the Scottish Environment Protection Agency (SEPA).

Marine Scotland scientists also licence:

Except where District Salmon Fisheries Boards discharge such responsibilities in relation to Atlantic salmon and brown (sea) trout.

The main Freshwater Fisheries Laboratory is in Pitlochry with additional manned outstations in Montrose (Angus) and Shieldaig (Wester Ross), with fish traps on upper Deeside.

Current priority areas for research to underpin development of policy include:

  • Interactions between marine renewable energy and migratory fishes

  • Interactions between coastal aquaculture and wild salmon and sea trout
  • Effects of change in thermal environment on salmonids and development of mitigation options
  • Protecting and enhancing spring salmon
  • Deriving conservation limits for salmon populations


Growth an mortality risk of Fish are influenced by water chemistry, the physical nature of their habitat and a wide range of predators, prey, diseases and parasites. These factors are key determinants of the variations in population strength that ultimately influence the success of fisheries. Long-term monitoring, both of habitat and fish populations, has been extremely important for understanding and hence managing fisheries effectively. The value of such monitoring is further enhanced when combined with experimental studies that shed additional light on the processes that connect variation in habitat to growth and survival of fish.

Monitoring is of value only if it fullfils a number of important criteria. It should be strategically planned, with a view to providing temporal and spatial coverage appropriate to well-defined aims. It must also be of appropriate quality, otherwise much power of inference is lost. We term such activities "scientific monitoring" since the aim is to provide information for robust scientific analysis. Such monitoring ranges from very carefully deployed networks of precision instruments to less controlled, but nevertheless valuable, provision of rod catches by fisheries proprietors.


Marine Scotland Science operates fish counters on the mainstem of the River N Esk, one of its tributaries, the Westwater, and on the River Helmsdale. Data from these counters form an integral component of Scotland's input to ICES working groups and are being combined with information from catches and traps to derive the status of Scottish salmon stocks.


Scientific investigations in support of Government policies generally combine review of existing knowledge acquired from literature study with experimental research and/or review and analysis of data from long term monitoring research. Here, the range of investigations currently being undertaken is categorised by the area being addressed or the fisheries subject:

Stocking Salmon

Generally there is little to be gained by stocking progeny of wild-caught salmon and sea trout unless fish are transferred from areas of abundant spawners to supply tributaries that are heavily impacted by hydro electricity generation.

However, there may be the potential to use stocking as a conservation tool to protect population in which numbers of spawners are extremely low, as may be the case in some tributaries that rear spring salmon. In such cases, it is predicted that redistribution of eggs from localised spawning sites may increase the overall production of smolts by enhancing dispersal and reducing local density-dependent mortality. This prediction has been tested experimentally in the Girnock Burn on the River Dee and the results of the work have been submitted for publication.

Aquaculture Interactions