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Genetic diversity in clonal organisms includes two distinct components, (i) the diversity of genotypes or clones (i.e. genotypic richness) in a population and (ii) that of the alleles (i.e. allelic and gene diversity within populations, and differentiation between populations). We investigated how population differentiation and genotypic components are associated across a gradient of eutrophication in a clonal marine plant. To that end, we combined direct measurements of sexual allocation (i.e. flower and seed counts) and genotypic analyses, which are used as an estimator of effective sexual reproduction across multiple generations. Genetic differentiation across sites was also modelled according to a hypothesis here defined as isolation-by-demography, in which we use population-specific factors, genotypic richness and eutrophication that are hypothesized to affect the source-sink dynamics and thus influence the genetic differentiation between a pair of populations. Eutrophic populations exhibited lower genotypic richness, in agreement with lower direct measurements of sexual allocation and contemporaneous gene flow. Genetic differentiation, while not explained by distance, was best predicted by genotypic richness and habitat quality. A multiple regression model using these two predictors was considered the best model (R(2) = 0.43). In this study, the relationship between environment and effective sexual-asexual balance is not simply (linearly) predicted by direct measurements of sexual allocation. Our results indicate that population-specific factors and the isolation-by-demography model should be used more often to understand genetic differentiation.

Sharing experiences and results among scientists and managers working on seagrass restoration was the main objective of the first European Seagrass Restoration Workshop that gathered researchers from around Europe. The meeting was the first forum in Europe that allowed for scientists, NGOs, and managers to interact and share their experiences relating to seagrass restoration and management. The results show that none of the seagrass restoration programs developed in Europe by the participants during the last 10 years was successful. Furthermore, an informal review of data published in seagrass restoration success, showed that the results reported were biased because they were mostly based on a very short monitoring period (i.e., This research was funded by the European commission through the LIFE Biomares project (LIFE 06 NAT/P/192)

Growth and reproductive cycle of the prawn, Palaemon adspersus were studied in Fornells Bay from April 2002 to March 2003. Samples caught using a lift net showed that abundance is markedly seasonal, with peaks in autumn and winter. P. adspersus showed distinct sexual dimorphism, the females being larger than the males. The K coefficient of the VBGF (Von Bertalanffy Growth Formula) was higher in the females (2.065 year−1 for females and 1.076 year−1 for males) and the same applies to L ∞ coefficient of the VBGF (47.8 mm in females and 34.14 mm in males). Ovigerous females were found from March to August. However, the low percentage of ovigerous females found in the study area suggests that reproduction and incubation do not occur at the study site. Also, as the ovary shows activity during the whole year cycle, it is not possible to distinguish a discrete reproductive period. El crecimiento y el ciclo reproductor de Palaemon adspersus fueron estudiados en la bahia de Fornells entre Abril de 2002 y Marzo de 2003. Las muestras obtenidas con una red por elevacion indican una marcada variacion estacional, con mayores abundancias en otono e invierno. P. adspersus presenta dimorfismo sexual, siendo de mayor talla las hembras. Los parametros de crecimiento calculados fueron superiores en hembras. El valor del coeficiente K de la VBGF (Formula de crecimiento de Von Bertalanffy fue 2.065 ano−1 para las hembras y 1.076 ano−1 para los machos. En el caso de L ∞, fueron 47.8 mm en hembras y 34.14 mm en machos. Se han encontrado hembras ovigeras entre Marzo y Agosto. En cualquier caso, el bajo porcentaje de hembras ovigeras encontradas sugiere que la reproduccion e incubacion no se desarrollan en el area de estudio. Esto unido a que la actividad del ovario se mantiene durante todo el ano no permite discernir un periodo reproductor claro.