Ciencia Colombia , Caldas, Lunes, 07 de marzo de 2016 a las 10:46

Environmental changes impact plankton diversity

Universidad Nacional de Colombia (UNal) researchers in Palmira discovered there is a high correlation between environmental variables (salinity, turbidity, depth, etc.) and the amount, presence or absence of plankton (diversity)

UN/DICYT For Andrés Molina Marine Biology doctorate candidate and Codirector of the Ecology and Acoustic Pollution Research Group (Econacua, for its Spanish acronym) in Buenaventura, plankton is more abundant in the seasons with greater salinity. This suggests a marked seasonal dynamic.

 

Plankton is a group of microscopic organisms divided into phytoplankton and zooplankton. The former is comprised of microalgae which are consumed by herbivorous zooplankton, which is also food for carnivorous zooplankton.

 

“These tiny organisms are necessary for sea life, as they are the base of the food pyramid which predators depend on,” said Environmental Engineering senior Jefferson Samboní Perafán.

 

Furthermore, they identified that plankton was more abundant in areas of greater depth and less turbidity. Therefore daily zooplankton vertical and horizontal migration variation could be due to tide and wave influence in search for food and safe harbor from predators.

 

Regarding turbidity, the outpour of the Anchicayá and Dagua Rivers produces a great amount of turbidity due to the large discharge of sediments and residue which obstruct the sun rays avoiding phytoplankton to perform photosynthesis, impacting the primary productivity and abundance of species.

 

Specifically they discovered that plankton is comprised mainly of phytoplankton, such as diatom species; and zooplankton comprised by copepods and zoeas (larval form of certain crustaceans). The latter are mostly predominant in periods of less rain which could demonstrate they have a preference for more marine than estuary conditions.

 

“Plankton diversity alterations could have implications on trophic networks, also influenced by contaminants, impacting the dynamics and coastal and marine ecosystems, therefore the importance of these projects,” said Samboní.

 

“On the other hand there are hardly any studies on the plankton of the Bay of Buenaventura, as most research on the Colombian Pacific Ocean have been performed in open sea,” said the Research Group and Thesis Director and Guillermo Duque Nivia, PhD in Oceanography and Coastal Studies.