Designing indicators for assessing the effects of marine protected areas on coral reef ecosystems : a multidisciplinary standpoint

The present paper aims at identifying and assessing indicators of the effects of Marine Protected Areas (MPAs) in coral reef regions, based on a bibliography review in ecology, economics and social sciences. First the various effects Studied within each of these domains and the variables used to measure them were censused. Potential ecological indicators were assessed through their link with the question used (here termed "relevance") and their "effectiveness" which encompasses the issues of precision, accuracy and statistical power. Relevance and effectiveness were respectively measured by the frequency of use of each indicator and the proportion of significant results in the reviewed articles. For social and economic effects, the approach was not possible due to the low number of references: we thus discussed the issue of finding appropriate indicators for those fields. Results indicate: 1- the unbalance in literature between disciplines: 2- the need for protocols and methodologies which include controls in order to assess MPA effects: 3- an important proportion of ecological indicators with low effectiveness: 4- the large number of ecological effects still not studied or not demonstrated at present

Movements of marine fish and decapod crustaceans: Process, theory and application

Many marine species have a multi-phase ontogeny, with each phase usually associated with a spatially and temporally discrete set of movements. For many fish and decapod crustaceans that live inshore, a tri-phasic life cycle is widespread, involving: (1) the movement of planktonic eggs and larvae to nursery areas; (2) a range of routine shelter and foraging movements that maintain a home range; and (3) spawning migrations away from the home range to close the life cycle. Additional complexity is found in migrations that are not for the purpose of spawning and movements that result in a relocation of the home range of an individual that cannot be defined as an ontogenetic shift. Tracking and tagging studies confirm that life cycle movements occur across a wide range of spatial and temporal scales. This dynamic multi-scale complexity presents a significant problem in selecting appropriate scales for studying highly mobile marine animals. We address this problem by first comprehensively reviewing the movement patterns of fish and decapod crustaceans that use inshore areas and present a synthesis of life cycle strategies, together with five categories of movement. We then examine the scale-related limitations of traditional approaches to studies of animal-environment relationships. We demonstrate that studies of marine animals have rarely been undertaken at scales appropriate to the way animals use their environment and argue that future studies must incorporate animal movement into the design of sampling strategies. A major limitation of many studies is that they have focused on: (1) a single scale for animals that respond to their environment at multiple scales or (2) a single habitat type for animals that use multiple habitat types. We develop a hierarchical conceptual framework that deals with the problem of scale and environmental heterogeneity and we offer a new definition of 'habitat' from an organism-based perspective. To demonstrate that the conceptual framework can be applied, we explore the range of tools that are currently available for both measuring animal movement patterns and for mapping and quantifying marine environments at multiple scales. The application of a hierarchical approach, together with the coordinated integration of spatial technologies offers an unprecedented opportunity for researchers to tackle a range of animal-environment questions for highly mobile marine animals. Without scale-explicit information on animal movements many marine conservation and resource management strategies are less likely to achieve their primary objectives