Demography, reproductive biology and trophic ecology of red coral (Corallium rubrum L.) at the Costa Brava (NW Mediterranean) : ecological data as a tool for management = Demographie, Fortpflanzungsbiologie und Ernährungsökologie der Roten Koralle (Corallium rubrum L.) an der Costa Brava (NW Mittelmeer) : ökologische Daten als Werkzeug im Management

• Main Author: Tsounis, G.
• Format: Other/Unknown Material
• Language: unknown
• Published: Alfred Wegener Institute for Polar and Marine Research 2005
• Subjects: Berichte zur Polar- und Meeresforschung; Reports on Polar and Marine Research
• Online Access: https://epic.awi.de/id/eprint/26173/; https://epic.awi.de/id/eprint/26173/1/Tso2005d.pdf; https://hdl.handle.net/10013/epic.25113; https://hdl.handle.net/10013/epic.25113.d001

The Mediterranean red coral (Corallium rubrum, L. 1758) is a characteristical gorgonian living in semidark habitats in the coralligenous zone of sublittoral hard bottoms. Despite being harvested commercially for the use of its red calcium carbonate skeleton in the jewelery industry, its ecology is still little understood. Thus the objective of this study was to increase knowledge on the population structure, reproduction and feeding ecology of red coral and to use these data to evaluate the efficiency of current management strategies of this species.The size/age structure of a population records valuable information, summarising the effects of mortality, recruitment and growth of past years. The six studied populations at the Costa Brava (NE Spain) consisted mainly of small/young colonies, as larger colonies are commercially exploited. Average size and age were estimated at 3 cm height and 7.5 years, whereas the species is capable of reaching 50 cm and 100 years. Furthermore, these young populations consist of colonies that have developed only few branches, offering considerably less three dimensional structure to the ecosystem than unharvested populations. One of the studied populations is located in a protected area, the Medas Islands Marine Park, and consisted of significantly larger/older colonies, thus allowing to distinguish harvesting effects from environmental ones.The reproductive output of red coral was found to significantly depend on colony size, having important implications for its management. Another aspect of potential importance for optimal harvesting is mesoscale variation of reproductive output. In a comparison of eight stations, however, we did not find significant differences, indicatig a homogenous reproduction. Colonies in deep water were found to spawn slightly earlier than shallow water ones, however, this phenomenon was observed only when temperature stratification in summer was particularly pronounced. Yet depth was not found to affect reproductive output itself, again in contrast to ...