Doctoral Programme on Marine Ecosystem Health and Conservation
 The MARES Researchers and their Research
Evaluation of conservation efficiency for gorgonians species at a regional scale based on an existing Marine Protected Areas network in the North Ligurian sea and scenarios modelling accounting for hydrodynamical connectivity
PhD Code: MARES_11_16:
Mobility
  • Host institute 1: P11 - Université Pierre et Marrie Curie (UPMC)
  • Host institute 2: P3 - University of Bologna
Research fields:
  • T6 - Habitat loss, urban development, coastal infrastructures and Marine Spatial Planning
Promotor(s):
  • Katell GUIZIEN
  • Marco Abbiati
  • BRAMANTI Lorenzo (philebo@gmail.com)
Contact Person and email: Katell GUIZIEN - guizien@obs-banyuls.fr

Subject description
Gorgonians are one of the most conspicuous components of rocky subtidal communities in polar, tropical and temperate seas. They play an important ecological role, providing habitats for epifauna composed of small species and increasing the biomass and diversity of the community. In Mediterranean rocky communities, Paramuricea clavata and Corallium rubrum are between the most important gorgonians structuring the benthic assemblages. A clear understanding of the mechanisms underlying distribution of these two species will be essential for an effective management plan and, when necessary, conservation actions.
These species have a sedentary adult phase, which ensures adults protection by protecting the habitat. However, these species, like many benthic invertebrates, have a complex life cycle with a planktonic larval stage during which dispersal by the hydrodynamics may lead to dramatic losses for a mother population. Thus, protecting the habitat can have no effect to ensure populations sustainability for these species if offspring retention rate is not large enough in the area of protection. On the other hand, dispersal from the Marine Protected Areas (MPAs) can also contribute to a stronger resilience of adjacent unprotected areas to human pressure. Thus, MPAs sustainability and efficiency appears not trivial to estimate and should be carried out regarding the objective of the MPA. Considering the goal of biodiversity conservation, as ecosystem engineers, gorgonians and corals health are good indicators of the marine protected area efficiency potential.
In the north western Ligurian Sea the presence of P.clavata and C.rubrum is well documented. The Marine Protected Area (MPA) of Portofino harbours populations of the two species and proceeding southern P.clavata can be found in 5 Terre MPA, Porto Venere Regional Park and Livorno area that is not protected and harbours populations of the two species. Extensive set of data on structure and dynamics of the above mentioned population are already available but still to be analysed.
Objectives of the PhD proposal
Comparison of the efficiency of the Marine Protected Area for these two species by analysing population growth rate in protected and non-protected areas
Numerical study of larval connectivity between suitable habitats for these species at the regional and local scales based on hydrodynamical modelling and larval swimming behaviour studies.
Experimental field study on connectivity by means of genetic techniques
Different scenarios varying the protected area location and size within the region will be tested using numerical simulations of realised population growth rate in locations where field surveys were carried out accounting for hydrodynamical connectivity. The efficiency of the current Marine Protected Area networks will be finally assessed in comparison with these scenarios.
PhD scheduling:
First year: data mining and synthesis of existing data of Paramuricea clavata and Corallium rubrum populations dynamics in protected and non-protected areas, organisation of complementary field surveys on populations distribution to be carried out during the first two years of the PhD (maximum 1 months per year), numerical study of larval dispersal at local and regional scales
Second year: Field study of populations genetic connectivity at local and regional scales, comparison with larval dispersal numerical simulations, paper writing
Third year: Protection scenarios testing with meta-population numerical modelling, comparison with realised population dynamics, paper and thesis writing

Expected outcomes
original publications : comparison between connectivity estimates based on larval dispersal numerical modelling and genetic techniques, scenarios testing for guiding spatial planning of protection measures

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Last update on 04/01/2017 -
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