*resources by artificial fish-reef engineering*. Vol.23, No.5, pp. 6-10 **Part 2**

**Water Management** 

100 Aquaculture and the Environment - A Shared Destiny

Zhang, H.H. & Sun L. (2001). Resources Science. *On reproduction increase of the sea aquatic* 

**6** 

*Spain* 

**Integrated Multitrophic Aquaculture:** 

Salud Deudero1, Ariadna Tor1, Carme Alomar1,

**Assessed with Stable Isotope Analyses** 

*1Centro Oceanográfico de Baleares, Instituto Español de Oceanografia, Palma* 

Aquaculture industry has rapidly increased from 20 million tons in the 1990s to 68.4 million tons in 2008, overcoming the 67.0 million tons of extractive fisheries, with an approximated global value of 84,791 million Euros (FAO, 2010). The Mediterranean Sea is an important producer of intensive open water fish culture, especially important are industries from Spain, France, Italy and Greece, which generated 2,133 million Euros in 2008 (FAO, 2008). Parallel to aquaculture industry development, knowledge of its effects on the surrounding environment is increasing. Several studies have been conducted to assess the environmental impact (Holmer et al., 2008; Yokoyama et al., 2006; Vizzini & Mazzola, 2004) due to aquaculture. Organic enrichment is recognized as the most important problem associated to marine aquaculture (Mirto et al., 2010; Troell et al., 2003) as a direct result of the release of dissolved and particulate nutrient loads, especially organic phosphorous and nitrogen in the form of ammonia that might easily induce eutrophication (Karakassis et al., 2000). Uneaten pellet and fresh food supplied at fish cages, together with the excretion products from

cultured fishes are the source of the nutrient loads released (Cheshuk et al., 2003).

Whereas the dissolved compounds are easily dispersed and diluted in the water column, the particulate compounds sink to the sea floor, causing severe modifications of the physical and chemical characteristics of the sediment and the community dynamics of marine seagrass and benthic fauna (Brown et al., 1987; Karakassis et al., 2000; Mente et al., 2006). The severity and extend of the environmental impact depends on a large number of factors, such as local hydrodynamics, water depth and total output from fish farms. Nevertheless, it has been detected organic enrichment in the sediment up to 1000 m from fish cages (Sarà et

The effects of the organic enrichment are widely studied in the Atlantic and the Pacific Ocean, especially in relation to the salmon industry (Brown et al., 1987; Cheshuk et al., 2003;

**1. Introduction** 

al., 2004).

José Maria Valencia2, Piluca Sarriera1 and Andreu Blanco3

*2Laboratorio de Investigaciones Marinas y Acuicultura, Andratx 3Instituto de Investigaciones Marinas de Vigo, CSIC, Vigo* 

**Filter Feeders Bivalves as Efficient Reducers** 

**of Wastes Derived from Coastal Aquaculture** 
