Description: The dataset compiles counts of larvae of the European flat oyster Ostrea edulis, settled on various substrates under three different experimental conditions. The data was collected within the AWI-RESTORE project (Alfred-Wegener-Institute, Germany), examining basic preconditions for successful restoration of the European flat oyster within the German Bight. The data is separated in three experimental setups: the columns for experiment 1 (hatchery/laboratory) include date stamp in ISO format, Latitude, Longitude, abiotic factors (Flow rate, temperature, salinity, pH, dissolved oxygen), substrate types, area and orientation as well as the count of settled larvae for each set-up. Data for experiment 2 (hatchery) include date stamp in ISO format, Latitude, Longitude, abiotic factors (Flow rate, temperature, salinity, pH), reef number, specifics of examined area and orientation as well as the count of settled larvae for each reef. Columns for experiment 3 (field) include date stamp in ISO format, Latitude, Longitude, abiotic factors (depth, temperature, salinity), chlorophyll concentration, substrate types, specifics and orientation as well as the count of settled larvae for each submerged substrate.

Description: Coral reefs are constructed by calcifiers that precipitate calcium carbonate to build their shells or skeletons through the process of calcification. Accurately assessing coral calcification rates is crucial to determine the health of these ecosystems and their response to major environmental changes such as ocean warming and acidification. Several approaches have been used to assess rates of coral calcification but there is a real need to compare these approaches in order to ascertain that high quality and intercomparable results can be produced. Here, we assessed four methods (total alkalinity anomaly, calcium anomaly, 45Ca incorporation and 13C incorporation) to determine coral calcification of the reef-building coral Stylophora pistillata. Given the importance of environmental conditions on this process, the study was performed under two pH (ambient and low level) and two light (light and dark) conditions. Under all conditions, calcification rates estimated using the alkalinity and calcium anomaly techniques as well as 45Ca incorporation were highly correlated. Such a strong correlation between the alkalinity anomaly and 45Ca incorporation techniques has not been observed in previous studies and most probably results from improvements described in the present paper. The only method which provided calcification rates significantly different from the other three techniques was 13C incorporation. Calcification rates based on this method were consistently higher than those measured using the other techniques. Although reasons for these discrepancies remain unclear, the use of this technique for assessing calcification rates in corals is not recommended without further investigations.

Description: The European flat oyster (Ostrea edulis) is an ecosystem engineer that provides important biogenic reef habitat with associated ecosystem functions and services. Most stocks have been commercially exploited and degraded; some are functionally extinct. Ecological restoration now aims to recover these degraded, damaged or destroyed ecosystems. Availability of seed oysters and substrate for successful larval recruitment has been identified as a major limiting factor for restoration projects in Europe. In substrate‐limited areas, restoration approaches have to involve the restoration of suitable substrates. The present study provides an evaluation of such potential substrate types. Various categories were investigated through hatchery and/or field experiments: (1) marine bivalve shells; (2) inorganic materials; (3) sandy sediment; (4) 3D sandstone reefs; (5) wood materials; and (6) limed materials. The respective settlement rates (settled larvae per cm2) indicate settlement preferences. Hatchery experiments showed significant preferences for bivalve shells and inorganic materials. Best settlement rates were observed on Mytilus edulis shells, followed by O. edulis shells as well as on slaked lime and on baked clay. Settlement was significantly higher on bottom‐oriented areas of bivalve shells and 3D reefs in laboratory experiments; however, this was not substantiated in the field experiments. Field experiments showed significant settlement preferences between substrate categories (bivalve shells, inorganic materials and wood materials). Best settlement rates were observed on baked clay, followed by slaked lime and bivalve shells. Wooden materials did not perform. Settlement rates and substrate preferences of larvae in controlled environments (laboratory, hatchery) differed from rates in the natural environment (field). This study provides a list of substrate types considering these specific environments. The relevance of these results for ecological restoration in the field and potential applications in seed oyster production are discussed.

Description: Sicydiinae species are amphidromous gobies, adults spawn in freshwater, whereas free embryos undergo a pelagic open sea phase. Post-larvae or juveniles are caught for human consumption when entering in freshwater after their pelagic larvae life in seawater. Such goby-fry fisheries are existing since centuries and widespread in tropical areas over the world. There are uncertainties related to caught volumes and trends but, overall, go-fry fisheries are declining and their sustainability is questionable. Aquaculture is a potential tool in conservation and management of wild goby stocks. Among Sicydiinae species, the red-tailed goby Sicyopterus lagocephalus is the most spread and used as a model species in numerous works involving amphidromous fish. The aim of the study was to evaluate the potential in aquaculture of the red-tailed goby through the analysis of the literature available on this species. We found that this species has some assets to be a potential candidate for aquaculture such as a short production cycle and a high fecundity as well as potential high market values. Nevertheless, given the small size at hatching and the long pelagic larval life, larval rearing is likely to be a challenging rearing phase but appears to be feasible based on past experiences with other goby species. Throughout the paper, we provided recommendations for future research in red-tailed goby aquaculture.