PROMOTING MARINE SCIENCE: CONTRIBUTIONS TO CELEBRATE THE 50TH ANNIVERSARY OF SCIENTIA MARINA.

SUMMARY: The current development of fishery research can be considered as much a technical development as a scien-tific-conceptual one. In relation to the technical development we analyse the evolution of the concepts fishing effort and fish-ing power, as well as vulnerability, availability and accessibility. In the conceptual analysis of the basic parameters we con-sider new contributions with regards to recruitment and evolution of populations based on concepts such as the system’s car-rying capacity and the effect of inverse density dependence. The impact of the available space is analysed as well as the effect of the prey-predator relationship in the context of the flows between the different levels in the trophic web. We point out that fishery analysis strategies need to consider that, from both the biological and socio-economic points of view, the system is never balanced but rather is at the very limit or even over the limit. On the whole, fishing (human action on the resource) can be understood within the context of the ecosystem. This situation implies introducing the concept of uncertainty. Aspects such as ecosystem elasticity are analysed in their broadest sense. In these terms, recovery of an ecosystem and of Large Marine Ecosystems (LME) is still possible, but the result can be different due to the appearance of opportunistic species. Some concepts such as fuzzy sets, and chaos and fractal analysis are important tools for analysing the evolution and man-agement of ecosystems exploited by fisheries