title: The influence of demersal trawl fishing gears on the resuspension of dinoflagellate cysts.
abstract: To investigate the influence of towed demersal fishing gears on dinoflagellate cyst resuspension, towing trials with four gear components were carried out at three sites of differing sediment type in the Moray Firth, Scotland. Samples of sediment plumes were collected using plankton nets mounted on a towed sledge. Diversity of resuspended dinoflagellate cysts was similar at all sites and included Protoperidinium and Gonyaulax spp., Proroceratium reticulatum and unidentified 'round brown' cysts. Cyst concentrations per gram of resuspended sediment varied by gear component and sediment particle size distribution. Gear components with lower hydrodynamic drag generated wakes with smaller shear stresses, mobilising fewer larger sand particles, giving larger concentrations of cysts. Muddy sediments contained higher cyst concentrations which declined with increasing grain size. This study has shown that fishing gear and sediment type can influence the redistribution of dinoflagellate cysts and highlights the importance this may have in relation to dinoflagellate blooms.
authors.affiliation: Marine Scotland Science, Marine Laboratory Aberdeen, PO Box 101, 375 Victoria Road, Aberdeen AB11 9DB, UK. Lyndsay.Brown@scotland.gsi.gov.uk
authors.forename: Lyndsay
authors.initials: L
authors.lastname: Brown
authors.forename: Eileen
authors.initials: E
authors.lastname: Bresnan
authors.forename: Keith
authors.initials: K
authors.lastname: Summerbell
authors.forename: Finbarr Gerard
authors.initials: FG
authors.lastname: O'Neill
mesh_terms: D000818:Animals; D004141:Dinoflagellida / Q000502:physiology*; D004784:Environmental Monitoring; D005398:Fisheries / Q000295:instrumentation* / Q000379:methods; D012606:Scotland; D014876:Water Pollution / Q000032:analysis / Q000706:statistics & numerical data