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- Greeve, Youk, et al.
(författare)
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Estimating and scaling-up biomass and abundance of epi- and infaunal bivalves in a Swedish archipelago region: Implications for ecological functions and ecosystem services.
- 2023
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Introduction As suspension-feeders, bivalves play a key role in maintaining regulatory functions of coastal ecosystems, which are linked to important ecosystem services. The functions attributed to bivalves depend on the life habits of a species (epi- or infauna) and their abundance and biomass. To properly quantify and assess these functions, detailed information the distribution, abundance and biomass at the ecosystem scale is critical. Amongst others, this requires an understanding on how environmental conditions shape special patterns in distribution. In this study we investigate this fundamental information on the Swedish west coast, an area where this information is lacking. Methods A survey which was designed to representatively sample both epi- and infaunal bivalves from randomized locations in various habitat types was conducted. Specifically, abundance and biomass of all species were recorded in the intertidal (0-0.5 m) and the shallow subtidal zone (0.5-2 m). The sites were distributed over an offshore gradient and at two exposure levels. This sampling structure allowed to extrapolate the results to an ecosystem level though information on the areal extent of these habitats using GIS layers. Results It was found that even though there exist a great variability among sites, in general epifaunal bivalves outweigh infaunal bivalves approximately 3 to 1. In terms of abundance, the ratio is more or less reversed and infaunal species occur in greater numbers. Most bivalves were found at an intermediate level of exposure, but due to the areal extend of the sheltered inner-archipelago this was the most important habitat for bivalve abundance and biomass. It was also found that invasive epifaunal oyster Magallana gigas and the invasive infaunal clam Ensis leei both dominated their respective groups in terms of biomass. Discussion Though the survey was relatively small, these results serve as a valuable insight of the relative importance of epi- and infaunal bivalves in this region. This gives understanding on which species and habitats are particularly important for ecosystem functions and services related to bivalves. This also provide a starting baseline for attempts to quantify ecosystem services provided by certain species or groups of bivalves in the future.
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| 2. |
- Jacobs, P., et al.
(författare)
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Successful rearing of Ostrea edulis from parents originating from the Wadden Sea, the Netherlands
- 2020
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Ingår i: Aquaculture Reports. - : Elsevier BV. - 2352-5134. ; 18:November
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Tidskriftsartikel (refereegranskat)abstract
- Since 2017, the European flat oyster (Ostrea edulis) reappeared in the Wadden Sea after decades of absence. In several countries, restoration and reinforcement projects have been initiated. Better insight in Ostrea behaviour is needed to ensure sustainable conservation in the future. In order to acquire substantial numbers of oysters for eco-physiological and transplant experiments without threatening the small local population, indoor rearing facilities were set-up at Royal NIOZ. Here, a broodstock of 38 adults originating from the western Wadden Sea, produced over 21 million larvae in 10 batches within 3 months (Sept-Nov 2018). Release of larvae and rearing took place at a water temperature of 19.7 ± 0.6 °C and a salinity of 30.5 ± 0.5 PSU. Outbreaks of Vibrio bacteria did not occur. The growth rate before settlement was 1.5–1.7 μm per day, which was at the low end of growth rates reported in previous studies. The first competent larvae were observed 17–22 days after release. Size at settlement varied between 255−325 μm. Survival until settlement was 0.96−0.98 per day. After settlement, growth rates increased to 30−47 μm per day, with batches that were released in September having a significantly higher growth rate and initial size compared to larvae that were released later. Mortality from release to the end of the experiment (Feb 2019) was 0.04−0.05 per day. A cryopreservation trial did not result in living larvae after thawing, most likely due to their advanced development when preserved. The larvae and juveniles were negatively tested for the parasite Bonamia ostrea and can thus be used in oyster conservation and restoration projects. Recommendations for future breeding attempts include the use of a higher water temperature and slightly higher food concentrations. © 2020 The Authors
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