Royal Society Publishing

This is more difficult than we thought! The responsibility of scientists, managers and stakeholders to mitigate the unsustainability of marine fisheries

J. F. Caddy , J. C. Seijo


The management of marine fisheries needs to undergo dramatic change in the new millennium, in response to the well–documented evidence of global overfishing and the general depletion of commercial fish stocks. The axioms of sustainable development and equilibrium productivity of wild ecosystems are identified as misleading concepts, which nonetheless underlie current approaches to the management of living marine resources. Current trends in marine fisheries landings worldwide provide little evidence of sustainability of marine resources under current management paradigms, where biological, economic and social aspects of fisheries are usually treated as different disciplines. While open–access conditions are less widespread than formerly, except for many straddling and highly migratory resources, fishers usually have access to the resource year–round throughout its range. Despite quotas, the nominal control of capacity and technical measures protecting juveniles, top–down management has generally been unable to prevent stock depletion, particularly of the older spawners that for demersal stocks often support recruitment.

An integrated solution to the complexity of managing wild resources seems not to have been achieved. Any new paradigm should assert the basic unpredictability of fisheries at the system level and require a broader range of performance indicators to be incorporated into the decisional framework. This must reflect the non–equilibrium nature of marine systems, and give greater importance to resource (as opposed to harvest) continuity in the face of regime shifts, and promote habitat restoration and conservation of genetic resources.

The new management framework requires co–management and collective decision–making to be incorporated within a precautionary and pre–negotiated management framework. This must explicitly recognize that decision–making occurs in conditions of model–based uncertainty and precautionary approaches should be incorporated at all levels, not least of which is to avoid the assumption that all resources can be harvested in a sustainable fashion through time. Redundancy in data inputs to management are needed to avoid the surprises that model–based sampling occasionally leads to, for example, when regime changes reduce productivity in response to climatic fluctuations. Emergency frameworks imposing non–discretionary rules must be invoked when overfishing and/or regime change trigger reference points indicating stock depletion. Non–discretionary recovery plans should then override rights–based systems and persist until fish populations recover to pre–established healthy levels, which may in turn need to await the return of a favourable regime.

In fact, some stocks may require periodic rebuilding after regime–induced collapses or because of a combination of ecological or economic impacts, hence a constant harvest policy may not always be possible. It will probably also be necessary to discard the axiom that a stock should be available to harvesting throughout its range and seasonal cycle. Technological advances mean that time– and area–specific access rights are now practical options, through satellite monitoring of vessel operations, even offshore.

More fundamentally, the basic axiom of ‘enlightened self interest’ underlying current methods of management will need to be tempered by an increased ethical concern for the fragility of natural ecosystems.