Marine protected areas as fisheries management tools
In the past MPAs have mainly been implemented in coastal areas to preserve marine habitats and to conserve biodiversity. However, in recent years there have been an increasing number of calls for interdisciplinary approaches to marine management, such as the widely cited “ecosystem approach to fisheries” (EAF), and MPAs are now increasingly being advocated to safeguard declining coastal fish stocks as well (Halpern, 2003; Hilborn et al., 2004). Coastal multiple-use MPAs can be found, e.g., in the tropics (Russ and Alcala, 1996; Abesamis and Russ, 2005), the north Pacific (Schroeter et al., 2001), and the Mediterranean and Atlantic regions (Dulvy et al., 2008; García-Charton et al., 2008). Often these coastal MPAs have a year-round no-take zone where all kinds of fishing activities are prohibited. Such a no-take zone is sometimes surrounded by a buffer zone or partial-take zone where commercial fishing is restricted to only small-scale or artisanal fishing (Claudet et al., 2008).
In contrast, in many temperate regions such as the Georges Bank (Stokesbury et al., 2007) in North America, the Emerald/Western Bank on the Scotian Shelf (Frank et al., 2000), or parts of the North Sea, known to be productive fishing grounds, areas are either temporarily or permanently closed for fishing by the respective fisheries management authorities, with the aim of enhancing survivorship of spawning adults or juveniles on nursery grounds. According to the life history of the respective target species, some fisheries closures or exclusive fisheries MPAs such as, e.g., the hake closures in north-west Spain can have a strong seasonal component with fishery exclusion only lasting a few weeks or months each year. Besides the seasonal banning of fishing activity, other management measures can include restrictions on the gear types permissible within designated areas (Frank et al., 2000) or the type of fishing vessels (e.g., the Maltese 25-mile zone). Many closures established, e.g., in Europe under the Common Fisheries Policy (CFP) were implemented as part of a package of measures to achieve a wider objective, for example recovery and replenishment of a particular stock (Scientific, Technical and Economic Committee for Fisheries, 2007).