On board the vessel Inndaga of the Geoma group
With the aim of studying the diversity of microalgae communities in the water column (phytoplankton) and in sediments (phytobenthos), an interdisciplinary group of researchers and students of various nationalities participated in a sampling in the Vigo estuary aboard the Inndaga vessel of the Geoma group. The activity, led by researcher Iria García Moreiras from the CIM, Marine Research Center of the UVigo, was developed under the auspices of the international workshop on dinoflagellate cysts recently held in Vigo.
The samples were collected at two strategic points in the Vigo estuary: one behind Mount of Guía, in the Teis cove, and another in a more external area at Punta de Alcabre, near the port of Bouzas—two shallow and semi-protected zones that favor the accumulation of cells in the water column and fine sediments on the bottom. The summer period is ideal for this type of study, as environmental conditions such as temperature and nutrient availability are optimal for microalgae development, making proliferations or blooms quite common. In fact, in the laboratory, under the optical microscope, a bloom of the dinoflagellate Noctiluca scintillans was identified in one of the water samples collected from Teis cove. This microalga contains pigments (carotenoids) within its cells that, when reaching high concentrations, color the waters a red-orange hue. Other microalgae with the capacity to produce toxins were also detected, including dinoflagellates of the genera Dinophysis sp. and Alexandrium sp., as well as the species Lingulodinium polyedra. Likewise, in the sediments, the presence of resistant structures or cysts of some of these species was confirmed, which have the capacity to germinate and form microalgal proliferations that could be harmful to the ecosystem.
Understanding the functioning and dynamics of marine ecosystems
Studies on the diversity and ecology of microalgae are important for understanding the functioning and dynamics of marine ecosystems, as they constitute the basis of the food chain. In addition, some species can produce toxic blooms that can have negative effects on other organisms, shellfish production, aquaculture and human health. This study also sought to identify possible resistance structures that could be formed by some microalgae (dinoflagellates) in the water column and deposited in sediments, these structures are called cysts and play a crucial role in the survival and dispersion of these microorganisms.
Seven scientists with specialties in different fields from the universities of Lisbon and Minnesota, and from three French institutions, the French Institute for Ocean Science (Ifremer), the Université Bretagne Sud and the Nantes Université, participated in the sampling, as well as Iria García Moreiras, who is developing part of her line of research on the distribution of microalgae in the Vigo estuary and their potential as environmental indicators.
The research activity of the CIM is supported by the Xunta de Galicia and the European Union through their co-financing under the Galicia ERDF Operational Programme 2014–2020.
Source: DUVI
