title: An assessment of juvenile Atlantic cod Gadus morhua distribution and growth using diver operated stereo-video surveys.
abstract: Stereo-video scuba transects were conducted during daylight hours from June to September 2013 within a proposed marine protected area (MPA) in the Firth of Clyde, west of Scotland. More juvenile Atlantic cod Gadus morhua of fork length (LF ) range 6-11 cm were observed in substrata containing mixed gravel, including maerl, than in boulder-cobble substrata with high algal cover, or sand with low density seagrass. Community composition was significantly different between substratum types. A decrease in G. morhua abundance was observed over the period of data collection. Over time, mean and variance in G. morhua LF increased, indicating multiple recruitment events. Protecting mixed gravel substrata could be a beneficial management measure to support the survival and recruitment of juvenile G. morhua; other substrata might be important at night given their diel migratory behaviour. Stereo-video cameras provide a useful non-destructive fisheries-independent method to monitor species abundance and length measurements.
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, U.K.
authors.forename: S A M
authors.initials: SA
authors.lastname: Elliott
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, U.K.
authors.forename: P A
authors.initials: PA
authors.lastname: Ahti
authors.affiliation: Department of Mathematics and Statistics, University of Strathclyde, 16 Richmond Street, Glasgow, G1 1XQ, U.K.
authors.forename: M R
authors.initials: MR
authors.lastname: Heath
authors.affiliation: Marine Scotland Science, Marine Laboratory, P. O. Box 101, 375 Victoria Road, Aberdeen, AB11 9DB, U.K.
authors.forename: W R
authors.initials: WR
authors.lastname: Turrell
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, U.K.
authors.forename: D M
authors.initials: DM
authors.lastname: Bailey
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D049628:Body Size; D017753:Ecosystem; D005398:Fisheries; D048389:Gadus morhua / Q000254:growth & development / Q000502:physiology*; D012606:Scotland; D011795:Surveys and Questionnaires; D014741:Video Recording
keywords: coastal; habitat; marine protected area; scuba; stereo-video cameras