Managing Molluscan Fisheries and Husbandry in Multi-user Zones
Roger L. Mann, Virginia Institute of Marine Science
Abstract
The current dilemmas facing management of molluscan resources in the intertidal and shallow subtidal regions are an accumulation of decades (sometimes centuries) worth of overlapping challenges. Early harvesters of extant species simply collected shellfish to satisfy their individual and commercial market needs. It is rare to find an instance where this did not eventually result in overfishing; however, exploitation typically continues because such fisheries are central components of local culture and economies. Current attempts to rebuild or even just stabilize remaining resources are rarely afforded long-term data to assess rebuilding targets, have little or no fishery-independent stock assessment, have poor fishery-dependent data, and are limited by a marginal understanding of metapopulation structure that supports recruitment in the targeted population(s). Superimpose on this canvas the use of the same intertidal and shallow subtidal real estate for intensive aquaculture—a practice that, although it also desires to maximize shellfish production for harvest, is primarily an economic venture with little concern for natural recruitment and mortality processes, although it is bounded by a suite of ecological variables. Finally, that same real estate footprint services other users—for example, recreational fishermen and waterfront property owners—who may view targeted exploitation in capture fisheries and/or intensive husbandry as limited user access and profit in a region sheltered under common property or riparian user designations. But these recreational and aesthetic uses are late additions to the management debate, and quantifying their value to the individual or society can be subjective in comparison to very direct economic impacts estimable from fishery and husbandry ventures. In this presentation I discuss some historical examples, emphasize the urgent need for data (as opposed to emotion) to describe present and future resource status, and suggest some structures on which to build a management plan.