Add-on conservation benefits of marine territorial user rights fishery policies in Central Chile

摘要

To combine the rational use of marine benthic resources and economic development of small-scale fishers, Chile passed legislation in 1991 establishing a comanagement policy that grants exclusive territorial user rights for fisheries (TURFS) to artisanal fisher organizations in well-defined inshore coastal areas, known as Management and Exploitation Areas for Benthic Resources (MEABRs). In general the policy has been proclaimed a management and economic success because benthic resource abundances have increased inside MEABRs in comparison with open-access areas. However, there is a lack of studies assessing the impact of this management policy on nontargeted subtidal species and community assemblages and the policy's implications for biodiversity and conservation. This study starts to fill this gap and links the allocation of TURFs for benthic resources with add on conservation benefits for species that are not directly linked with the fishery policy. Comparative subtidal surveys inside vs. outside MEABRs were used to assess the effects of three MEABRs on managed targeted benthic species, biodiversity (species richness), and community assemblages in central Chile. Surveys focused exclusively on subtidal kelp forest habitats dominated by Lessonia trabeculata, spanning 4-12 In in depth and with similar levels of habitat complexity. The study comprised: (1) quantification of kelp forest complexity, (2) understory survey of sessile species, (3) quantification of conspicuous benthic macroinvertebrates, including those under management, and (4) quantification of reef-fish species inside the kelp habitat. Results showed population enhancement of target-managed invertebrates inside MEABRs. Moreover, reef-fish species were significantly more diverse and abundant inside MEABRs, and community assemblages of nontarget benthic invertebrates and reef fish were significantly different inside vs. outside MEABRs. The comanagement of inshore benthic resources in Chile, through MEABRs aims for the sustainability of invertebrate and algae stocks. However, our study shows that this management tool, which in practice restricts access to the entire management area, provides important conservation add-on effects for species that are not the focus of the management policies. Therefore, in Chile, the hundreds of already established MEABRs could represent an important ancillary network, which complements the biodiversity objectives of fully protected areas such as no-take marine protected areas or others.