In order to study the management options in a coastal lagoon with intensive shellfish (Tapes philippinarum) farming and macroalgal (Ulva sp.) blooms, a biogeochemical model has been developed. The model considers the nutrient cycles and oxygen in the water column as well as in the sediments, phytoplankton, zooplankton, and Ulva sp. dynamics. Furthermore, a discrete stage-based model for the growth of Tapes philippinarum has been coupled with this continuous biogeochemical model. By studying the growth of lams, it considers the nutrient contents in the water column as well as its temperature, including the effects of harvesting and the mortality due to anoxic crisis. The results from 1989 to 1999 show that the model is able to capture the essential dynamics of the lagoon, with values in the same order of magnitude as the measurements from experimental campaigns and with data on clam productivity. The model has therefore been used to assess the effects of Ulva’s mechanical removal on the lagoon’s eutrophication level using the exergy and specific exergy, as well as economic factors in terms of operating vessel costs and averaged prices for clams as optimization parameters. The results show that a combination of ecosystem models and health indicators constitute a sound method for optimizing the management in such complex systems.

ZALDIVAR COMENGES Jose';  AUSTONI M.;  PLUS Martin;  DE LEO G. A.;  GIORDANI G.;  VIAROLI P.; 

2006-03-17

CRC-Press

JRC32194

https://publications.jrc.ec.europa.eu/repository/handle/JRC32194,