PhD Thesis coming soon

LANDSCAPE FRAGMENTATION AND RESILIENCE IN SEAGRASS MEADOWS

by Alessandro Gera

This thesis is an attempt at approaching seagrass ecosystems from a landscape perspective, with the aim of increasing knowledge about the processes generating patterns at large spatial scales, and understanding how these patterns interact with other drivers of seagrass function. Specifically, we focus on (i) understanding the dynamics of habitat fragmentation, (ii) how this fragmentation interact with other seagrass disturbances, such as hydrodynamism, sedimentation and herbivory  and which are the consequences of such fragmentation to biodiversity and ecosystem processes.

Presentation day: June 21, 2013 at the Universitat de Barcelona (Spain)

 

LUCINID BIVALVES PROJECT

June 2013

In November 2012 two members of our group (Marta Pérez and Guillem Roca) participated in the 10^th International Seagrass Biology Workshop celebrated in Brazil. There, they attended to an interesting presentation about the role of lunicid bivalves on seagrass performance in reduced sediments, as they have symbiotic sulphide oxidizing bacteria in their gills. This work has been published in Science under the title “A three stage symbiosis forms the foundation of seagrass ecosystems” (Van der Heide et al. 2012).

With that in mind, we wondered if these bivalves could play a significant role on the performance of Cymodocea nodosa meadows in Alfacs Bay (Ebro delta), since they occur in reduced sediments, leading us to propose a one year project, to be developed by a master student (Laura Solé), for answering such question.

The first exploratory survey, conducted on March 19^th 2013, confirmed the presence of these bivalves in the rhizosphere of Cymodocea nodosa plants growing in Alfacs bay. The dominant species was Loripes lucinallis, with densities ranging between 400 and 2,300 of living clams per square meter.

Now, we aim at (1) ascertaining the distribution and abundance of this species across the bay and (2) assessing its role in the maintenance of Cymodocea nodosa meadows in Alfacs bay.

Alfacs Bay (delta de l'Ebre)

Cymodocea nodosa in Alfacs Bay

Loripes lucinallis