Marine Ecology Progress Series

The urgent need to reduce the intense pressure and destructive power that modern fishing practices apply to the world’s fisheries, and the oceans that support them, is now widely recognized (e.g. FAO 2002a, Hilborn et al. 2003). However, there is far less agreement over the exact levels to which fishing mortality must be reduced and over how to reduce the indirect effects of fishing (e.g. bycatch, destruction of the seafloor), in order to ensure sustainability of catches and the health of marine ecosystems. And this is to say nothing of disagreements over how these goals might be achieved. It has proven all too easy for various factions—including some fishery scientists—to blame our having arrived at the current crossroads on the ineffectiveness of existing management practices, and on the scientific advice that underlies it. Driven by these forces, and in recognition of the significant direct and collateral impacts that fishing imposes on marine ecosystems, an Ecosystem Approach to Fisheries (EAF) is rapidly being adopted by institutions charged with stewardship of the marine environment (e.g. NOAA 1999, Brodziak & Link 2002, FAO 2003, Garcia et al. 2003, Sinclair & Valdimarsson 2003). In conjunction with this EAF is the implementation of Marine Protected Areas (MPAs), including marine reserves. Both EAF and MPAs implicitly recognize that the value (to humanity) of the whole ecosystem is much greater than the sum of its parts—a commendable step forward in-and-of itself. However, there is some disagreement over whether the EAF, and MPAs, truly represent alternatives that will be any more effective in assisting us with sustainable management of marine resources than historical practices. Regardless of the approach that is taken to decide upon catch limits, or on the location, size and number of MPAs, there will always be the complicated (and socio-economically-politically charged) question of how these policies should be implemented and enforced; that is, governance (see, for example, Mace 2001, Sissenwine & Mace 2003, Caddy 2004, Cochrane 2004, Stefansson 2004). To address these issues, we solicited essay-style contributions from several of the marine and fishery scientists who are at the forefront of the ongoing debate. Those essays are presented here. We will not use space summarizing the content of this Theme Section (TS)—we encourage you to read through it. Rather, we take this opportunity to highlight some of the most important conclusions that issue from the essays when they are taken as a whole and to add some commentary of our own. The acronyms used in this TS are listed in Table 1. In the critical recommendation of such fishery management tools as limits on maximum fishing mortality, minimum spawning stock biomass, or total allowable catch levels, fishery scientists often disagree about seemingly subtle (to the layman) aspects of data analysis and interpretation. Although debates such as these are at the core of the scientific process, the fact that fishery scientists themselves do not always agree has been the focus of socio-political criticism, and is surely one of the reasons that advice on catch quotas is not often strictly heeded. In the case of the contributions to this TS, written by proponents sitting on both sides of the fence, there is a convincing consensus on most of the key issues. While there is disagreement over just