The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Ana Cristina Brito January 2006 Universidade do Algarve

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Ramsar site Natura 2000 candidate site Natural Park Caetano et al. (2002):

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal events such as 'Harmful Algal Blooms', decreased water transparency and decrease in oxygen concentration. Eutrophication (OSPAR, 2001) - enrichment of water by nutrients causing an accelerated growth of algae and higher forms of plant life Activities may lead to: Undesirable disturbance

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Tett et al. (2003) indicated that the observed maximum value of chlorophyll was twice the predicted to Ria Formosa exchange rate not correct for inner channels some important sources of chlorophyll are not been taken into account Alvera-Azcárate et al. (2003) have suggested that macrophytobenthos may play a significant role in nitrogen balance, the limiting nutrient within Ria Formosa ? Newton et al. (2003) suggested that nutrient fluctuations within Ria Formosa may be associated with blooms of microphytobenthos

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal The aim of this project is to develop a model, which will be able to estimate the assimilative capacity of the Ria Formosa. Evaluate the role of benthic primary producers in the system; Adapt the CSTT model to Ria Formosa system; Test the model, critically, against both historical and field data; Develop and assess the usefulness of specific indicators, which can be used in the assessment of the trophic status of the system; Evaluate the assimilative capacity of the Ria Formosa. Objectives:

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Development of the model Pelagic component will be based on a modification of Riley’s dynamic model The model will incorporate a benthic part, taking into account the phytobenthos (macro and microphytobenthos) From Tett and Wilson (2000)

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Sampling Model: Phytoplankton Phytobenthos Chemical parameters (nutrients, oxygen, pigments, particulate matter) Physical characteristics (temperature, salinity, turbidity) Trophic status: Zooplankton Zoobenthos

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Experimental work A key parameter of the CSTT model is the yield of chlorophyll from nitrogen (q)! The yield (q) for microphytobenthos will be determined by adapting to the benthic system the microcosms’ methodology used by Edwards and co- workers (Edwards et al., 2005) This will allow the measurement of the corresponding fluctuations of chlorophyll and nutrients in the water.

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal Implementing, testing and improving the model The model output (simulations) will be tested against observations and historic data The current situation will be assessed and different scenarios, with alternative reductions in nutrient discharge, will be estimate

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal The project will be developed both at Napier University and Algarve University. 6 months at Napier University 6 months at Algarve University

The Development of an Assimilative Capacity Model for the Sustainable Management of Nutrients within the Ria Formosa, Portugal References Alvera-Azcárate, A., Ferreira, J.G., Nunes, J.P., Modelling eutrophication in mesotidal and macrotidal estuaries. The role of intertidal seaweeds. Est. Coast. Shelf Sci., 57, Caetano, M., Ferreira, J.G., Icely, J., Newton, A., Nunes, J.P., Vale, C., Ria Formosa. In: Gilpin, L., Tett, P. (Eds.) OAERRE Sites Description Report. Napier University, Edinburgh. Edwards, V., Icely, J., Newton, A., Webster, R., The yield of chlorophyll from nitrogen: a comparison between the shallow Ria Formosa lagoon and the deep oceanic conditions at Sagres along the southern coast of Portugal. Est. Coast. Shelf Sci., 62, OSPAR, Draft Common Assessment Criteria and their Application within the Comprehensive Procedure of the Common Procedure. Meeting of the Eutrophication Task Group,London,9-11 October 2001, Annex5. Ospar Convention For The Protection of The Marine Environment of The North-East Atlantic. Newton, A., Icely, J.D., Falcão, M., Nobre, A., Nunes, J.P., Ferreira, J.G., Vale, C., Evaluation of the eutrophication in the Ria Formosa coastal lagoon, Portugal. Continental Shelf Research, 23, Tett, P., Gilpin, L., Svendsen, H., Erlandsson, C.P., Larsson, U., Kratzer, S., Fouilland, E., Janzen, C., Lee, J., Grenz, C., Newton, A., Ferreira, J.G., Fernades, T., Scory, S., Eutrophication and some European waters of restricted exchange. Continental Shelf Research, 23,