Jean-Georges Harmelin

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A new technique for aging red coral Corallium rubrum (L.) colonies based on staining the organic matrix found in the axial calcareous skeleton is presented and validated. This method provided clear-cut images of growth rings of red coral. To demonstrate their annual periodicity, two approaches have been used: (i) applying this technique to adult colonies of(More)
Microhabitat attributes were characterized for recently settled juvenile fishes in six species of Sparidae (Diplodus annularis, D. puntazzo, D. sargus, D. vulgaris, Oblada melanura, and Sarpa salpa) on the rocky shore near Marseille, French Mediterranean coast. Depth, slope, type of substratum, biotic cover and hydrodynamic conditions were recorded wherever(More)
An unprecedented mass mortality event has been observed at the end of the summer 1999 along the coasts of Provence (France) and Ligury (Italy). This event has severely affected a wide array of sessile filter-feeder invertebrates from hard-substratum communities, such as sponges (particularly the keratose sponges Hippospongia and Spongia), cnidarians(More)
The organisation of the coastal rocky fish community of Lebanon was investigated for the first time, using visual censuses. A total of 62 fish species were recorded between the surface and 32 m depth, 8 species being Red Sea migrants. Species richness and fish abundance were positively correlated first with substrate complexity and second with depth. The(More)
The Levant Basin (SE Mediterranean) is the most exposed to the introduction of non-indigenous species. The current assessment of exotic bryozoans present along the coast of Lebanon has been completed by the recording of fourteen cheilostome species (one cryptogenic) collected by diving in 17 localities (2-42 m). This set of exotic bryozoans comprises ten(More)
After its accidental introduction in the French waters of the Mediterranean, the green seaweed Caulerpa taxifolia is now spreading along the coast of the Alpes-Maritimes, invading various biotopes (rock, sand and Posidonia oceanica seagrass beds). During the spring and fall of 1992, we evaluated the impact of C. taxifolia on the infralittoral ichthyofauna(More)
Overexploitation leads to the ecological extinction of many oceanic species. The depletion of historical abundances of large animals, such as whales and sea turtles, is well known. However, the magnitude of the historical overfishing of exploited invertebrates is unclear. The lack of rigorous baseline data limits the implementation of efficient management(More)
We compared the structure of a seagrass fish assemblage near a sewage outlet before and after improvements to wastewater treatment. To determine whether responses by the fish assemblage were due to changes in water quality or to other factors, comparisons were made with the structure of a fish assemblage from a nearby site unaffected by sewage effluent.(More)
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