engleski

ECASA Study site report: Dalmar, 47 pp.

During the summer of 2006, Sea Bass and Sea Bream fish farm located near Pakoštane, Croatia was visited twice in order to complete fieldwork program within ECASA project. Main purpose of this program, beside evaluation of various environmental state indicators, was to assess the performance of KK3D deposition model. Visits to the study site were carried out on 30 June – 8 July and 23 – 28 July 2006. Fish farm at study site is being operated by Dalmar Ltd. from 1999. At present, total production is approximately 400 tons/year. Initial yield of fish at study site was below 50 tons/year. After two years in operation, Dalmar’ s management decided to increase production to the present level. Such expansion is not possible without a detailed Environmental Impact Assessment (EIA) study. Study was completed in 2001 and site was declared as suitable for intensive aquaculture. In particular, (i) currents are strong enough to maintain optimal water quality in the net pens at all stages of production, (ii) local topography provides sufficient protection from waves and wind, (iii) surrounding waters are not polluted and (iv) moderate increase of nutrient sources in the area is not likely to cause deterioration of regional water quality. During the field campaign samples were collected of the water column and sediment. Most of the indicators of environmental impact reveal the state of the environment at one particular moment in time. Analysis suggests that these indicators are not reliable for assessment of impact. Probable cause is the timing of sampling – one cannot expect to capture unfavorable conditions with samples taken instantaneously. Some indicators, however, integrate the effect of fish farm on the environment during several days. These indicators seem to produce distinguishable results when placed near fish farm in comparison with the reference station. We used data from sediment trap deployment to test the predictive capability of KK3D model. KK3D was designed to be used within EIA studies before production of fish begins. Comparison of model output with observed data suggests that model slightly underestimates deposition of particulate organic matter on the bottom. Performance does not deteriorate over the whole range of observed values.

Dalmar fish farm; KK3D model; verification

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