|Connect – Connectivity of marine populations assessed with genetic and numerical modelling tools|
Programme - PTDC/BIA-BDE/65425/2006
Execution dates - 2008-01-01 - 2011-03-31 (39 Months)
Funding Entity - FCT
Funding for CESAM - 145680 €
Total Funding - 150000 €
Proponent Institution - Universidade de Aveiro
Instituto de Ciências e Tecnologias Agrárias e Agro-Alimentares – Porto
The Connect project concerns the assessment of the spatial scales of connectivity of populations of a coastal marine species, along a one-dimensional stepping-stone array of demes. In marine species with indirect development (i e, with a larval phase) gene flow between populations depends on the distance separating the populations and on the interaction between duration of the larval phase, larval behaviour and current patterns.
The project will analyse this problem in the crab Carcinus maenas, which forms large populations in estuaries along the coast of the western Iberian Penninsula. C. maenas has a larval phase that develops in coastal waters during 4 to 6 weeks, from late winter to early summer. During this period of the year the coastal ocean of western Iberia is subjected to two different regimes: a poleward flow during winter, driven by southerly winds associated with the passage of cold fronts, and an equatorward flow after the spring transition, when northerly upwelling-favourable winds dominate the circulation. Several discontinuous events of larval supply to the estuaries can be detected during the larval season. The Connect project will address the following questions:
The Connect project will use a set of 20 available DNA microsatellite markers to describe the genetic structure of the populations along the geographic gradient from Asturias to Algarve. Larvae supplied to the Ria de Aveiro will also be analysed for the same genetic markers. If there is a geographic structure of population differentiation along the geographic range, then it should be possible to assign the larvae recruiting to the Ria de Aveiro to a source population or set of contiguous populations. An oceanographic numerical model coupled with an individual based model that simulates larval behaviour will also be used, in order to describe the advection history of the larvae forming each supply event and to investigate possible differences in connectivity along the range of populations.
By using a multiple approach - assessment of geographical structure, assignment of larvae to source populations, and modelling of dispersal ranges based on oceanography and larval behaviour - we hope that the Connect project may contribute to our understanding to the mechanisms regulating gene flow and connectivity among marine populations.