This study investigates the effect of hypersalinity, both alone and in combination with elevated temperature, on the cosmopolitan cold-water coral Desmophyllum dianthus from the Chilean Fjord region to assess its acclimatization potential to Mediterranean conditions, where the species can also be found. Specimens were collected in Comau Fjord (Chile) and maintained in aquaria at the Alfred Wegener Institute (Germany) in three different treatments for three months: 1) Control with Chilean temperature (11°C) and salinity (31), (2) Chilean salinity with Mediterranean temperature (12°C), and (3) Mediterranean temperature and salinity (12°C and 38, respectively). The growth rate of the corals was investigated at the end of the 35-day acclimatisation pertiod and after 50 days under experimental conditions. The short- and long-term respiration rate of the corals was measured after 3 and 50 days of exposure. Polyp extension rates were determined 5 times per week both in the morning and in the evening.
Vegetative and morphometric corallite traits were quantified on skeletal samples of the cold-water coral Lophelia pertusa (syn. Desmophyllum pertusum). The aim was to characterize the morphological diversity of this species at the level of corallites. Morphometric measurements were taken with caliper and tape measure in two replicates, in order to be averaged to reduce measurement error. The analyzed skeletal samples had been collected from various locations in the Atlantic Ocean and the Mediterranean Sea during multiple cruises, and are kept at the Senckenberg am Meer (SaM) institute in Wilhelmshaven, Germany.
Objective: The HERMIONE project is designed to make a major advance in our knowledge of the functioning of deep-sea ecosystems and their contribution to the production of goods and services. This will be achieved through a highly interdisciplinary approach (including biologists, ecologists, microbiologists, biogeochemists, sedimentologists, physical oceanographers, modelers and socio-economists) that will integrate biodiversity, specific adaptions and biological capacity in the context of a wide range of highly vulnerable deep-sea habitats. Gaining this understanding is crucial, because these ecosystems are now being affected by climate change and impacted by man through fishing, resource extraction, seabed installations and pollution. To design and implement effective governance strategies and management plans we must understand the extent, natural dynamics and interconnection of ocean ecosystems and integrate socio-economic research with natural science. The study sites include the Arctic, North Atlantic and Mediterranean and cover a range of ecosystems including cold-water corals, canyons, cold and hot seeps, seamounts and open slopes and deep-basins. The project will make strong connections between deep-sea science and user needs. HERMIONE will enhance the education and public perception of the deep-ocean issues also through some of the major EU aquaria. These actions, together with GEOSS databases that will be made available, will create a platform for discussion between a range of stakeholders, and contribute to EU environmental policies.