I'm not sure about the Med, but some parallels might be drawn with conservation measures implemented in the North Sea and around the British Isle - UK and Scottish Government data is quite good regarding.

On a very local level the Isle of Man has some successful marine reserves - again data on these comes up if you Google search. 

Most of the fisheries resources including Mediterranean region are fully exploited or over exploited especially the capture fisheries resources worldwide. The situation is not helping coastal poor which have been deteriorating due to non performing wealth with a negative rate of return in fishing activities. Marine capture fisheries is therefore one of the remaining examples of human endeavour which engages with the direct extractions of wild animal population for consumption. A study looked at 27 countries that depend significantly on coral reef fisheries for food and ranked them according to their exposure and sensitivity to the effects of climate change and human-made disturbances, as well on their capacity to adapt to changes (Hughes, et.al. 2012).

Capture fishery is a clear outcome of the productivity of the ecosystem. In fact, the fisheries have an effect on and affected by the ecosystem components and their interactions. Thus, EBFM is imperative as fishing always impact on the bio diversity of the ecosystem. The identification of system components together with their interactions is a vital step in this direction. EBFM aims to ensure that, despite variability, uncertainty and likely natural changes in the ecosystem, the capacity of the ecosystems to produce food, revenues, employment and, more generally, other essential services. Further, than that the livelihood is maintained indefinitely for the benefit of the present and future generations to cater both for human as well as ecosystem well-being. Therefore, a responsible fisheries management should be taken into account for the sustainability together with the profound interactions between fisheries and their supportive ecosystems. As a result, EBFM is an emerging concept which has been identified as an effective and sustainable approach to manage the deteriorating fisheries ecosystems (FAO, 2003). The main goal of EBFM is to maintain the eco system health and sustainability. Ecosystem provides a wide variety of useful services that improve human welfare.

As per the FAO (2003), the EBFM implies conservation of ecosystem structures, processes, and interactions through sustainable use. At the same time it should look into a proper balance of development which supports the local livelihood (Wattage and Mardle, 2005) and rural poverty. EBFM does not attempt to manage or to manipulate the ecosystem processes rather it ensures that fisheries management decisions do not adversely affect the ecosystem functions and productivity. There, the concern is long term sustainability basically about harvesting target stocks and the resultant economic benefits. Hence, this is different from the traditional management approaches as it focuses on individual stocks or species.

• FAO (2003) Technical Guidelines on the ecosystem approach to fisheries, FAO Rome.

• Wattage, P. and Mardle, S., (2005). Identifying stakeholder preferences towards conservation versus development for a wetland in Sri Lanka, Journal of Environmental Management, 77, 122-132.

Sustainable development can be defined as a development that “meets the needs of the present without compromising the ability of future generations to meet their own needs.” In such conditions, the management and conservation of the natural resources and the orientation of technological and institutional changes should be made in a way to ensure the attainment of fixed goals and to satisfy the human needs for present and future generations. Such development should conserve resources avoiding environment damages, in a technologically appropriate way, economically profitable and socially acceptable.

The UN Convention on the Law of the Sea (UNCLOS) addressed the issue of protection of marine ecosystems from damaging activities and harm, but also the way exploitation may contribute to a sustainable development.

A further development of the concept occurred during the International Conference on Responsible Fishing the concept of sustainable development of fisheries .

In many fishing areas resources are not being utilized in a sustainable manner and cope with many problems as overfishing and poor economic performance. Overcapacity and overfishing produce an increase of social stress and conflicts related the access to some fisheries resources and allocation of these limited resources among different users.

Sustainable fisheries means that the exploitation of the Mediterranean resources will continue to produce benefits for people far into the future. Sustainable fisheries does not only mean suitable harvesting levels. The new challenge is how to deal with enhancement of quality rather than quantity of production. Such enhancement can be got improving trade, access to markets, certification of quality of fisheries’ products, by education aimed at increasing the attention on the need of reduction of the impact of fishing on the environment.

In the EU Mediterranean countries in 2006 the 'Mediterranean Regulation' was approved aiming at improving fisheries management policies in order to achieve sustainable fisheries, to protect the marine environment and restore fish stocks to healthy levels. A transition period of 3 years was agreed for a number of its provisions, but there are still many delays and several member states failed taking the measure needed for a full implementation of the regulation. Mediterranean fisheries cannot be managed only by a single country or by European Union regulations, but needs of the involvement of all the sea-facing countries. This is due to the interactions between fisheries an in particular due to the presence of many shared stocks. This action is developed within some international organisations such as the GFCM (General Fisheries Commission for the Mediterranean) and ICCAT in the case of tunas. In the frame of such international fora, collaboration, data share and studies aimed at improving the scientific knowledge and identification of problems and solutions are promoted.

In the Mediterranean mainly fisheries are multi-specific and many stocks are exploited with different gears. Many fisheries are conducted with too small vessels that land their catches along a wide system of ports and landing places. The data collection of such fisheries is quite difficult and the compilation of logbooks for this kind of small vessels is not feasible. Collection of catch, effort, age structure of the catches is very difficult and assessments of stock status regard only a very limited number of stocks. Such difficulties make almost impossible the adoption and enforcement of a sound management system based on catch limitations (TACs). There is however the need of management of fisheries resources, that according to the available (but limited) information appears overfished, exploited too young and with too high a fishing effort) and at low levels of biomass. Many species that were fished in the past are in this moment considered locally under extinction.

Other than a general reduction of fishing pressure, management in the Mediterranean should be take into consideration some technical measures related to an enhancement of the way resources are exploited and a reduction of undesired impact on both the commercial resources and the marine ecosystem. Such technical measures should cope to different issues as: improvement of gears selectivity, the protection of sensitive habitats, prohibition of some fishing practices, limitation of the maximum dimensions of passive fishing gears, limitation of the operations with active fishing gears as trawlers, purse seines, dredges in coastal areas, definitions of minimum conservation size of fish, regulation of recreational fishing, etc.

While national management plans are important to take into consideration specific resources and stakeholders needs, it is also important at regional (Mediterranean) level to keep common standards aimed at the implementation of a long–term approach to a sustainable management for the whole Mediterranean. Many of the characteristics of the gears used in traditional Mediterranean fisheries are in contrast with present regulations and needs of management plans for obtaining derogations regarding mesh size, distance from the coast. 

It is difficult to give a general answer to your question. Even though general rules apply everywhere, the specific characteristics of each country, available resources, fisheries, economy, culture, have to be taken under consideration

As was very well described by Dr. Abella, the Mediterranean fisheries are characterised by fragmented fleets, usually composed by small vessels, use of large number of landing sites, multi-species catches and low catches per unit of effort. Most of the fish caught are recruits (0-1 years) of the main target species. Until recently, no regular assessments were made by international working groups and the results of the assessments made rarely were incorporated in management. Moreover there are different fishing methods targeting the same species and remarkable recreational fishing activity (at least 10% of total landings). European statistics indicate there are some 4,300 larger ‘industrial’ or ‘semi-industrial’ units, mainly trawlers and purse seiners, operating from EU ports in the Mediterranean. However, the ‘small scale’ sector, which includes coastal and artisanal fisheries, is especially important. It is estimated that more than 40,000 small scale units are operating from EU ports. This is believed to be less than half of the total number of small vessels fishing in the Mediterranean.

The main problem of the Mediterranean fisheries is overfishing, since the development of semi-industrial and industrial fishery has led to an overexploitation of many fishable resources. Impact of fishing gears to the marine ecosystems (e.g. impact of trawlers on the Posidonia beds) is another important issue, since one of the key principles of ecosystem-based fisheries management is the need to protect ecosystems and populations by applying the precautionary principle, which includes halting destructive fishing methods. In the Mediterranean, catches are falling, the fish caught are getting smaller and some species are becoming rarer. Mediterranean fleets need to fish less and with less environmental impact, improve compliance with the rules, reinforce co-operation between fishermen and scientists and strengthen multilateral co-operation. Thus the return to the alieutic exploitation of the coastal zone through the development of artisanal fishery appears mandatory for Mediterranean fishery. The small-scale fisheries, suitably governed, are still our best hope for sustainable utilisation of coastal resources (Pauly, 2006). However, although small-scale fisheries are potentially, and in many cases actually, more sustainable than large-scale fisheries (they don’t destroy the bottom like the industrial trawlers, they don’t discard, they can target species, etc.), they are disadvantaged because of their typical remoteness, lack of infrastructure, and marginal political power. Furthermore, small-scale fisheries are at a disadvantage when competing for fisheries resources and market access with heavily subsidized industrial fleets.

Mediterranean waters have a very long history of local management from the 3rd millennium BC down through the centuries via the medieval guilds and ‘brotherhoods’ (Prud’homie in France, Confradias in Spain) to modern times. This tradition of local territorially-based management shows that the common pool resources of the seas were benefit of appropriate and effective management. The idea of imposing rights on coastal resources is also emerging as an approach for managing coastal fisheries. The problems of enforcement of regulations in the Mediterranean suggest that management-based incentives, or indirect incentives resulting from systems with increased fishermens’ involvement in the management process, would ultimately be more effective in controlling fishing. Thus the participation of the fishermen in the crucial decision making processes will be the decisive factor for law enforcement and successful management.