9.6 Interactions among aquaculture, capture fisheries and the environment in coastal lagoon management
9.6.1 Interactions between commercial and recreational fisheries
Some recreational fishing is carried out in the surroundings of some coastal lagoons as the Albufera of Valencia and parts of Ebro delta, but there are no strong interactions with commercial fisheries. In any case, licences and authorizations are necessary for recreational fishing.
Recreational fishers sometimes sell their products on the local market, which represents a competition for commercial fishing. In the Mar Menor, both forms of fishing also coexist, but they are regulated and require licences.
In almost all these areas there are sports fishing associations, the aims of which are primarily recreational, and which have a weak control over catches.
9.6.2 Interactions among different fishers groups and conflicts between fishers/fish farmers and public or private stakeholders
In some lagoons, sometimes there are people who are developing recreational fishing and shellfish harvest without authorization and consequently there is no registry of their catch and its relative value. Moreover, there are no associations defending the interests of the sector in marketing the product and fishers sell their production directly to consumers (individuals, restaurants, local fish markets, etc.). This generated major conflicts with authorized commercial fishers.
South Atlantic area
In south Atlantic lagoons, fish is stolen inside the culture facilities and the lagoons. This type of actions is common in the Bay of Cadiz, where the theft of fish by people is a rather serious problem affecting the viability of the companies exploiting the lagoons in some cases.
Illegal fishing steals the aquaculture productivity and they damage economic production and production processes.
9.6.3 Competition for space
In general, there is no competition for space, but what there is the need to improve the use of space. Some sites, which are protected as natural parks, have a planning management and zoning based on conservation and environmental protection of their ecological values through the management of their uses. Each one of the areas has a degree of protection to manage space, through authorizing compatible activities. Both lagoon management and government control are very strong due to environmental protection.
9.6.4 Product interaction on the market
No significant interactions occur between the products of fishing and aquaculture, as they usually are different species and sizes. Both types of products are well differentiated in the fish market and each product has its own market.
As coastal lagoon fisheries and aquaculture provide very small productions, they do not cause disturbances or instability in the market.
9.6.5 Organic input from aquaculture activities
For the extensive or semi-intensive aquaculture activities carried out in lagoons do not produce wastewater rich with organic substances; only in some areas where aquaculture activity is more intense, for example in the Bay of Cadiz, wastewater flowing out of aquaculture facilities is controlled and monitored by the environment authorities.
However, considering the production levels, they will not generate significant organic inputs. In any case, wastewaters in most lagoons derive from other activities such as agriculture and villages built near the lagoons and often affect lagoon water quality.
9.6.6 Environmental effects of aquaculture and capture fisheries on biodiversity conservation
Nowadays, the environmental effects of aquaculture and fishing activities are not well quantified, nevertheless, it is recognized that aquaculture developed in this area is compatible with environmental protection. The development of aquaculture supports the conservation of natural areas (marshes and salt marshes) and helps to keep the flooded areas by increasing biodiversity (birds, fish, mollusks and plants).
9.6.7 Impact of ichthyophagous birds
In Atlantic areas, there have been many studies on the influence of the presence of cormorant (Phalacrocorax sp.) populations in aquaculture.
Studies on the incidence of fish-eating birds demonstrate that there is a significant impact they can have on aquaculture facilities and on production (Perez-Hurtado et al., 1997). According to producer associations, in some extensive aquaculture facilities, cormorants may prey on 40– 60 percent of the production.
9.6.8 Elements for green accounting and ecological services
The main sources of energy in the environment of coastal lagoons examined come from the electricity network, while renewable energy is rarely used.
In most of the regions analyzed, there are inventories of wastewaters in quality and quantity flowing into coastal lagoons, therefore there is a monitoring of potential discharges that could affect lagoons. These inventories normally depend on the corresponding authority responsible for the environment in each Spanish region.
• The fees in the lagoons are mainly related with the use of public space, for which the operator of the lagoon or part of it has to pay a price per occupied or used square meter. In Mediterranean coastal lagoons, rates are oriented towards the places where discharges occur.
• With regard to marketing, producers and the authorities responsible for food security in every region should track product processing and production quality control. • In recent years, there have been some accidents or oil spills near the lagoons, as it occurred near Veta la Palma, where the breaking of a tailings pond (mining industry) affected the whole surrounding area. Also in the Ebro delta, an oil spill from a platform located along the coast of Tarragona was close to entering the delta and to affecting the whole ecosystem.
• There is no significant evidence of industrial accidents linked to fisheries and aquaculture in the lagoons studied.
The environmental benefits generated by most lagoons are related to the maintenance of wintering and/or migratory bird communities, and the ecological value is generated by the protection of flora and fauna.
Maintaining the landscape has become increasingly difficult in some cases, as the Mar Menor, where urban development and infrastructure are a real risk to the visibility of natural areas.