5. Critique of the Scientific Evidence for Fisheries Benefits of MRs

Three sets of generalisations about the benefits of MRs are heard from nature protectionists (NPs). First, NPs claim that MRs provide biodiversity benefits. For example, Grorud-Colvert et al. (Marine protected areas: a multidisciplinary approach, 2011, p. 293) asserted that ‘Growing scientific information has shown consistent increases in species density, biomass, size, and diversity in response to full protection inside reserves of varying sizes and ages located in diverse regions’. Second, NPs claim that MRs generate fisheries benefits. For example, Geoffrey Lean (The Independent, 2009), the environment correspondent of The Independent, stated that ‘Establishing ‘no-take zones’…has been strikingly successful around the world; marine life has rapidly recovered and spread to surrounding areas, greatly increasing fish catches’. Third, NPs claim that MRs provide socio-economic benefits. For example, Fletcher et al. (Mar Policy 45:261–268, 2014, p. 264) held that ‘There is evidence that…MPA networks have successfully been used for both fisheries management and to increase social and environmental welfare’.