title: Lobster and cod benefit from small-scale northern marine protected areas: inference from an empirical before-after control-impact study.
abstract: Marine protected areas (MPAs) are increasingly implemented as tools to conserve and manage fisheries and target species. Because there are opportunity costs to conservation, there is a need for science-based assessment of MPAs. Here, we present one of the northernmost documentations of MPA effects to date, demonstrated by a replicated before-after control-impact (BACI) approach. In 2006, MPAs were implemented along the Norwegian Skagerrak coast offering complete protection to shellfish and partial protection to fish. By 2010, European lobster (Homarus gammarus) catch-per-unit-effort (CPUE) had increased by 245 per cent in MPAs, whereas CPUE in control areas had increased by 87 per cent. Mean size of lobsters increased by 13 per cent in MPAs, whereas increase in control areas was negligible. Furthermore, MPA-responses and population development in control areas varied significantly among regions. This illustrates the importance of a replicated BACI design for reaching robust conclusions and management decisions. Partial protection of Atlantic cod (Gadus morhua) was followed by an increase in population density and body size compared with control areas. By 2010, MPA cod were on average 5 cm longer than in any of the control areas. MPAs can be useful management tools in rebuilding and conserving portions of depleted lobster populations in northern temperate waters, and even for a mobile temperate fish species such as the Atlantic cod.
authors.affiliation: Flødevigen Marine Research Station, Institute of Marine Research, Nye Flødevigvei 20, 4817 His, Norway. even.moland@graduates.jcu.edu.au
authors.forename: Even
authors.initials: E
authors.lastname: Moland
authors.forename: Esben Moland
authors.initials: EM
authors.lastname: Olsen
authors.forename: Halvor
authors.initials: H
authors.lastname: Knutsen
authors.forename: Pauline
authors.initials: P
authors.lastname: Garrigou
authors.forename: Sigurd Heiberg
authors.initials: SH
authors.lastname: Espeland
authors.forename: Alf Ring
authors.initials: AR
authors.lastname: Kleiven
authors.forename: Carl
authors.initials: C
authors.lastname: André
authors.forename: Jan Atle
authors.initials: JA
authors.lastname: Knutsen
mesh_terms: D000818:Animals; D049628:Body Size; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D005398:Fisheries / Q000379:methods*; D048389:Gadus morhua / Q000254:growth & development*; D008121:Nephropidae / Q000254:growth & development*; D009664:Norway