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Laboratorio de Investigaciones Marinas y Acuicultura (LIMIA)

Summary

Human activities are altering the between-individual natural variability of fitness-related life traits in many different ways. A well-known example is that large fishes are more vulnerable to fishing gears. Survival differentials can translate into harvesting-induced selection of certain phenotypes and usually reduce resource profitability. Conventional resource management is aimed to improve such a profitability but targets at population-level benchmarks (e.g., fishery profits) and focuses in single traits (e.g., the enforcement of the minimum size rule). Conversely, recent theoretical ecology frameworks emphasize both the multivariate nature of individual phenotypes, and the relevance of individual functioning. The dynamic adaptive landscape theory proposes that population- and community-level patterns arise from the way the variance-covariance among several traits fits into a fitness landscape. In the context of PHENOFISH, this landscape is being modified by human harvesting. A related theory, the pace-of-life, also stresses the relevance of the processes favoring specific combinations of correlated phenotypic traits. Initially, physiological traits were only considered, but recent evidence strongly suggests that harvesting selects for certain risk-taking behavioral traits and that this selection can generate changes in other traits.

Rooted in this theoretical background, PHENOFISH aims to go a step further than describing the correlation patterns between the life traits associated with harvesting. The PHENOFISH initial hypothesis is that behavior structures the individuals of harvested populations into either a vulnerable or a non-vulnerable pool. PHENOFISH also hypothesizes that vulnerable and non-vulnerable fish operate in a different way, in the sense that the transference processes of mass and energy depends on the vulnerability degree of a given fish. Specifically, PHENOFISH attempts, at the individual level, (1) to disentangle the behavioral mechanisms that make an individual more or less vulnerable to be harvested, and (2) to provide a mechanistic understanding of the outcomes of individual behavior on other life traits by means of a Dynamic Energy Budget (DEB) model.


Moreover, PHENOFISH will explore how such an individual functioning perspective can improve our understanding of the ecological and the subsequent social/economical consequences of selective fishing. Specifically, PHENOFISH attempts, at the population level, (3) to describe the spatial pattern of vulnerability of several populations along the south coast of Mallorca, (4) to combine such a spatial pattern with empirical data of reproductive output at fish-level for upscaling reproductive output at population-level and (5) to evaluate the effect of accounting for vulnerability in metapopulation connectivity, through the use of a spatially explicit Individual Based Model (IBM).


PHENOFISH integrates ecology of individuals with fisheries theory in order to generate new knowledge for improving harvesting management. The project will combine knowledge from marine biology and physical oceanography. Moreover, the project will benefit from the collaboration of managers (Govern de les Illes Balears) and fishers (commercial and recreational associations). Finally, the project is aimed to develop new technology for analyzing underwater images, thus contributing to improve the way data from marine systems are obtained and analyzed.

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