ScottishPower Renewable Energy Limited is proposing to develop the Argyll Array offshore wind farm, located 5 km off the south west coast of Tiree in the Scottish Inner Hebrides. The original development site covered an area of 361 km2, occupying waters ranging between 0 and 45 metres depth, though more recently this has been scaled down by ~40% (Figure 1). Argyll Array is considered to be of strategic national importance to the UK and will contribute both to renewable energy targets and the emergence of a novel industry considered to be of considerable economic potential (ScottishPower Renewables 2010).
The potential environmental effects of the Argyll Array development will be identified as part of the Environmental Impact Assessment (EIA), and the developer will seek to avoid, reduce or offset any adverse effects through mitigation measures. The EIA process runs in conjunction with the design of the project such that once potential impacts are identified, the design of the project will be adjusted and mitigation measures proposed accordingly.
An integral part of any EIA is an appreciation of the baseline status of the ecology within the area, including designated species and/or habitats. This document presents a review of current knowledge regarding the basking shark Cetorhinus maximus in the vicinity of Argyll Array; including an overview of the species biology, ecology and conservation status, as well as a more detailed review of several pieces of recent and current research. Additionally, the findings of the boat-based surveys commissioned for Argyll Array in relation to basking shark sightings patterns. Using the review and the analyses herein, a detailed impact assessment for basking sharks around the Argyll Array wind farm development is presented.
The basking shark (Cetorhinus maximus) is the world’s second largest fish and one three species of shark known to filter seawater for food. It has a unique feeding strategy which dominates all aspects of its ecology and life history (Sims 2008). Many aspects of basking shark life history and biology are currently poorly understood and this review aims to summarise the current available knowledge on the species globally and with specific reference to the Argyll Array site.