 |
Global climate changes have, in the last decades, reached center stage in the attention of both the scientific community and the society at large, impacting biodiversity at all levels of organization. This is particularly true for coastal zones, especially deltas, that are extremely sensitive to changing forcing conditions related to climate variability, such as flooding and droughts, storm surges, and sea-level changes. The Po Delta is among the most important shellfish cultivation area in Europe - with about 1600 operators and more than 80 companies involved - thanks to the high load of suspended organic matter and inorganic nutrients carried by the Po River that sustain the productivity. In last years, the shellfish production in the area has experienced a strong decline as consequence of multiple effects related to climate change. It must be stressed that the major part of lagoon food webs interested by shellfish farming in the area are driven by phytoplankton dynamics, as benthic floristic assemblages are regularly extirpated to provide additional physical and functional space for the cultivated biomasses. However, despite its role, the scientific information regarding the phytoplankton ecology in the Po Delta lagoons is still scarce, especially in relation to filtration activities of cultivated biomasses. Phytoplankton is considered to be the first biological compartment to rapidly respond to environmental changes in aquatic systems, as well as the most digestible trophic source for filter feeders organisms. Thus, the use of phytoplankton functional traits can represents an important tool for both ecological studies and shellfish production policies, opening new perspectives in management and planning of productions. The present communication focuses on the evaluation of phytoplankton functional traits in a coastal lagoon of the Po Delta, Sacca degli Scardovari (place of origin of Cozza di Scardovari PDO) where the recent explosion of the invasive blue crab (Callinectes sapidus) led to the collapse of the entire economically productive system. Our results highlight the role played by freshwater inputs in driving the productivity of the lagoon as well as the control by filter feeders organisms on primary producers. The overall picture underlines the extreme vulnerability of this system to ongoing climate change, as well as the need to deal with extreme urgency with the emergency relating to the explosion of the blue crab population.
- Poster
