Individuals to populations: The potential effects of large tidal arrays on mobile marine populations INDI-POP

Lead Research Organisation: University of Aberdeen
Department Name: Inst of Biological and Environmental Sci

Abstract

The first full scale commercial tidal turbine array in the world is being deployed this autumn in the Pentland Firth by MeyGen (www.MeyGen.com). The cumulative environmental impacts of arrays cannot yet be fully understood and, in the spirit of deploy and monitor, MeyGen will progress with this first array while being closely monitored by the regulator, Marine Scotland (MS). The University of Aberdeen (UoA), via the research outcomes of several NERC grants (FLOWBEC, RESPONSE, FORSITE) is at the forefront of the design and successful collection of the type of continuous acoustic data and advances in analysis that has global agreement to be the best method of measuring potential environmental effects of tidal arrays. UoA has current KTP project with MeyGen and in addition to previous data collected at the site, will be collecting live and continuous range of acoustic data from the array location. This NERC CASE PhD will be involved in transforming the current analysis of this new data from the level of understanding of how animals are changing their behaviour around tidal turbines to see if those changes lead to population level effects, positive or negative.
There is a high potential for marine renewable devices to induce individuals, whether they are fish, seabirds or mammals, to change their normal foraging, resting or migration behaviours due to the introduction of the devices to an area previously devoid of protruding and moving structures, changes to physical flow patterns and changes to noise/pressure. Current research from UoA is showing changes to, at least, prey (fish) behaviour with the introduction of single test turbines. All of these changes have potential to lead to impacts at the population level of predators (seabirds & Mammals) through cumulative changes in individuals in the 1) amount of energy/time used for foraging/migration, 2) success rate of predation/escape and 3)mortality risks through collision with man-made rotating structures.
To create more certainty in this industry understanding is required of whether or not all of these potential changes will lead to significant impacts at the population level. This level of understanding would lead to reliable and confident licensing of development proposals. It has taken decades of research to produce detailed mechanistic models that drive the population dynamics of many fish, seabird and marine mammal populations. This PhD research will stand on the shoulders of that detailed individual-to-population modelling and add accurate functional response relationships between energy/time use changes in individuals so as to be able to weight up the relative risks of significant changes at population levels due to the addition of large scale renewable developments.
This PhD will build on the new understanding of fine scale animal behaviour derived from our current NERC CASE PhD (FORSITE) and the other previous multidisciplinary NERC-funded projects (FLOWBEC, RESPONSE). The outcomes of this project will be, first, to specify methods of how best to define the quantifiable relationships between changes in energy/time use, successful predation/escape, and collision mortality risks with the changes brought about by introduction of structure and change in physical flow. This will produce functional response curves linking energetic/time budget changes with changes in prey behaviour, flow rates, turbulence characteristic and blade speeds. The second level of outcome of the project will be to produce general functional relationship models that have outputs at the population level for a range of species types (fish, seabirds, mammals) that takes into consideration the cumulative effects of these changes. The third outcome will be to create a generic modelling approach (testing if many species have the same types of functional response curves to the same type of bio-physical changes) so this type of method could be applied to other renewable industries.

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