Modelling essential habitat for common scoter (Melanitta nigra) in a disturbed environment. (5th October 2022)

• Record Type: Journal Article
• Authors: Breen, Patricia; Clarke, Sarah; Tully, Oliver
• Is Part Of: Estuarine, coastal and shelf science. Volume 276(2022)
• Publication Date: 2022-10-05
• Subjects: Common scoter -- Disturbance -- Habitat alteration -- Benthic bivalves -- GAMs -- Fishing; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2022.108007
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: The realised distribution of species in disturbed environments depends upon the degree to which their optimum habitat has been altered by impacts arising from human pressures. We investigated how pressures such as fishing activity, changes in prey availability and habitat quality affect the distribution of Common Scoter (CS) in the north Irish Sea. CS distribution data were obtained from aerial surveys in the winter of 2018–2019. We developed two generalised additive models using covariate information on depth, seabed shear stress, VMS activity of fishing vessels, AIS data of passenger and cargo vessels, portion of fine sand in the benthos, abundance of deep-burrowing bivalves and abundance of surficial bivalves. There was no clear evidence that the fishery, through either disturbance effects nor direct prey competition caused by extraction of razor clams, affected the distribution of CS in the area. However, indirect effects of the fishery, mediated through impacts on abundance and perhaps recruitment of bivalves on CS, could not be ruled out. The absence of a disturbance effect may be due to the small size of vessels in this fleet and their slow fishing speeds. The abundance of surficial bivalves, depth, the portion of fine sand and shear stress at the seabed in the sediments influenced CS distribution. This indicates that the distribution of CS in the area is driven by foraging conditions rather than the presence of fishing vessels. Highlights: The distribution of common scoter is related to the ease of foraging and the presence of prey. There is no indication that the razor clam fishing fleet is affecting common scoter distribution. There is no indication that the razor clam fishing fleet is causing disturbance to common scoter. There was no direct prey competition between the razor clam fishing fleet and common scoter.