No-take zones

There is increasing concern that too few MPAs exist and that there is in reality too little protection for those that do, in both developed and developing countries, in warm and cold waters. This has recently lead to a call for increasingly large areas to be placed under strict protection within 'marine reserves'.

Marine Reserves (MRVs) are areas of the sea completely protected from all extractive activities. Within a reserve, all biological resources are protected through prohibitions on fishing and the removal or disturbance of any living or non-living marine resource, except as necessary for monitoring or research to evaluate reserve effectiveness. Marine reserves are sometimes called 'ecological reserves,' 'fully-protected marine reserves,' or 'no-take areas.' MRVs are a special category of Marine Protected Areas (MPAs). MPAs are areas designated to enhance conservation of marine resources. The actual level of protection within MPAs varies considerably; most allow some extractive activities such as fishing, while prohibiting others such as drilling for oil or gas.

The majority of fishing methods are size selective and specifically target larger individuals within a stock. Many are also specific in the sense that they target specific groups of fish. Although there is an initial cost, in the form of reduced catch, to the fishery of establishing a no-take zone, they have been shown to provide benefits in the medium to long term with exclusion zones containing higher species richness (especially amongst the higher trophic levels) and larger individuals in greater abundance than adjacent open areas. Fecundity increases exponentially with body size in fish and in many cases around the world migration out of the exclusion zones has enhanced catches in adjacent areas, more than compensating for the initial decline.