PHYTORIA - Environmental regulation of phytoplankton in the Ria Formosa coastal lagoon
Ref. PTDC/MAR/114380/2009
Budget (Total/UALG-CIMA): 125.536€/101.956€
Starting date: January 1st., 2011
Ending date: December 31st, 2013
Coordinator: Helena Galvão
Domain: Marine sciences
Phytoplankton is the dominant primary producer in most aquatic ecosystems, and a sensitive gauge of ecological status and change. Yet, the ecological role played by phytoplankton vary among functional groups or species.
Recent studies revealed that phytoplankton in coastal ecosystems is undergoing marked changes, both in terms of biomass, composition, and phenology, which could be linked to local anthropogenic influences and climate change. However, the underlying causal links between environmental and phytoplankton changes are difficult to establish due to the lack of process-oriented studies at the species level, and the common use of a biased research strategy that overemphasizes phytoplankton growth and neglects phytoplankton mortality.
The fundamental goal of this proposal is to understand the environmental drivers of specific groups of phytoplankton in a coastal system, the Ria Formosa coastal lagoon (southern Portugal), an aspect recently identified as a key determinant to forecast ecosystem responses to environmental. The Ria Formosa is located in a region classified as very vulnerable to climate change and it suffers multiple anthropogenic impacts. The lagoon is a breeding and feeding ground for fish and birds, and supports a wide range of human activities including tourism, fisheries, and shellfish farming.
The specific objectives of this proposal are:
- to characterize phytoplankton abundance, biomass, activity and specific composition over an annual cycle;
- to evaluate the role of abiotic (e.g., light, nutrients, temperature) and biotic (pelagic and benthic grazing, viral lyses) environmental factors that drive phytoplankton seasonality and composition, and their relevance over the seasonal cycle;
- to understand the overall impact of increases in water temperature and light upon phytoplankton dynamics and composition.
To reach these objectives, an interdisciplinary approach will be used that combines a descriptive field study and an experimental analysis of phytoplankton species-specific bottom-up and top-down controls and their interactions. The research team has in-depth expertise in phytoplankton ecology, phagotrophic protists, metazooplankton and benthic assemblages, and extensive experience in studying this type of ecosystem. Indeed, the background of this proposal includes recent scientific work on phytoplankton variability (Rocha et al. 2002,
Domingues et al. 2005, 2007, Domingues & Galvão 2007), top-down controls of phytoplankton (Sommer et al 2004, 2005, Sommer & Sommer 2006, Sommer 2008, 2009), and global warming (Sommer et al 2007, Sommer & Lengfellner 2008).
The overall contribution of this project proposal is to provide an accurate assessment of the environmental drivers of specific groups of phytoplankton in the Ria Formosa coastal lagoon.