Selección de indicadores para la evaluación de las áreas marinas protegidas

Resumen

Marine Protected Areas (MPAs) have become popular tools worldwide for ecosystem conservation and fisheries management. They reduce the effects of over fishing of coastal marine stocks, preserve marine biodiversity, and ensure sustainable socio-economic development for human communities. But though MPAs are functioning and accomplishing their objectives, they must be managed. MPAs nowadays are facing their most dangerous threat, how to be managed effectively. Tools for management are needed and indicators are widely being proposed as one of them. Despite of the great number of indicators found in the bibliography, they do not accomplish the necessary characteristics to be good indicators and fewer are the cases where their validity has been proved. This thesis reviewed the indicators used in the bibliography that assessed the protection effects. To supply the gaps found a list of parameters to be defined as indicators were identified. 169 parameters were defined using the driver-pressure-state-impacts-response (DPSIR) framework. The model was applied to three MPAs (Tabarca MPA, Cabo San Antonio MPA and Sierra Helada and Islotes de Benidorm MPA) in the south eastern of Spain, assessing their effectiveness and validating the conceptual model. To identify the parameters as validate indicators three evaluations were applied: 1) Availability and quality of data in the corresponding institutions: To be useful, information on indicators must be available in the corresponding institutions, and thus gathering it is one of the main tasks before applying them. The aim was to evaluate the availability and quality of the information obtainable for the parameters defined to assess MPAs effectiveness in the conservations of marine resources. 2) Statistical analysis of long temporal data series: With underwater visual census (UVC) for fish from 34 case studies which correspond to 13 MPAs generated a final database including 3098 samples of abundance data and 2729 samples of biomass. With fisheries biomass data samples obtained from 11 different fishing gears from 11 MPAs, a final database that included 40978 samples was generated. All the MPAs were located from the North-Western Mediterranean to central-Eastern Atlantic. Data ranged from one year before the establishment of the MPA to 34 years after it. Species were categorized within taxonomic, trophic and commercial categories. The aim of this study was to: i) assess which parameters were the best indicators of the protection effect for data estimated by UVC census and fisheries samples; ii) determine which of them respond effectively to different structural characteristics of the MPAs and iii) validate with independent data the indicators proposed. 3) Evaluation of the preferred indicators by stakeholders: To evaluate which were the preferred indicators by managers a survey of their opinions was undertaken through questionnaires. The evaluation was based on mangers knowledge in order to select the best indicators form the whole list of parameters defined. Managers were classified in two groups: administration level and type of administration resources management. The opinions of managers were measured using summated rating scores. Finally 24 questionnaires answered were obtained. The results reflected the most valuated parameters and the possibility to use them as indicators. Finally the three evaluations were joined, with the aim to obtain a set of parameters as indicators to assess the protection effect. From each evaluation final data was obtained for each parameter. This data was standardized in a way to obtain a final value. Finally the parameters were classified as bad, medium or good indicators and recommendations for management and future studies are given.