This page will contain brief summaries of some of the research carried out by the Marie Curie training in receipt of ECOSUMMER funding.
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Joana Dias - Evolutionary
genetics of the Mytilus edulis complex in Scotland
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Tânia Cristina dos Santos Diniz - Identifying and mapping the overlap in resource exploitation between marine mammals and fisheries along the Galician coast |
Scottish
shellfish production was until recently thought to be based exclusively on M.
edulis, the endemic species. In the light of recent findings describing
the presence of non-edulis species in Scotland, it is clear that the real extent
of these species and their hybrids is not known.
A more accurate knowledge of Mytilus species distribution is imperative,
particularly with respect to the aquaculture industry which could be faced with
the problem of dealing with the production of more than one species, which may
show differences in growth rate, environmental preferences or breeding times.
With the objective of analysing a considerable amount of samples taken at a
national scale to assess the presence of these species in Scotland, a molecular
method for identification using real-time PCR was developed. The primers and
probes developed have shown to be both sensitive and specific for the detection
of M. edulis, M. trossulus and M. galloprovincialis, proving
to be successful in identifying up to a minimum of one adult M. trossulus
in pooled tissue samples of 36 individuals.
The method shows also potential for application to the detection of mussel larvae
in plankton samples. The identification and possible quantification of larvae
from plankton will allow the application of this method to the study of mussel
larvae distribution and seasonal occurrence in Loch Etive. This type of data,
together with the identification of spawning maxima for M. trossulus
and M. edulis from histological observation of gonads, may result in
valuable information towards targeting specific areas and/or times for settlement
and/or collection of spat of the most valuable farmed species, M. edulis.
This
study related cetacean diversity and sightings rates in Galician waters to oceanographic
and physiographic features. Water depth was obtained from the GEBCO Digital atlas,
and sea surface temperature and chlorophyll-a (Chl-a) concentrations estimated
from remote sensing data. A Geographic Information System (GIS) allowed the exploration
and visualization of the nature of these relationships, and Generalised Additive
Models (GAMs) were used to test the hypotheses generated by the GIS. Water depth
was the most important factor affecting sightings rates, the highest sighting
rates being associated with the water depths within 200 to 600m depth. GAM results
indicated that geographical location, water depth and Chl-a concentrations explained
up to 67% of variation in cetacean sighting rates. These relationships may arise
through environmental effects on prey abundance.