Characterisation of the Bacteria and Archaea Community Associated with Wild Oysters, At Three Possible Restoration Sites in the North Sea

With 85% of the global oyster reefs destroyed, there is an urgent need for large scale restoration to benefit from the ecosystem services provided by biogenic oyster reefs and their associated biodiversity, including microorganisms that drive marine biogeochemical cycles. This experiment established a baseline for the monitoring of the bacterial and archaeal community associated with wild oysters, using samples from their immediate environment of the Voordelta, with cohabiting Crassostrea gigas and Ostrea edulis, Duikplaats with only C. gigas attached to rocks, and the Dansk Skaldyrcentre, with no onsite oysters. The microbial profiling was carried out through DNA analysis of samples collected from the surfaces of oyster shells and their substrate, the sediment and seawater. Following 16S rRNA amplicon sequencing and bioinformatics, alpha indices implied high species abundance and diversity in sediment but low abundance in seawater. As expected, Proteobacteria, Bacteroidetes, Firmicutes and Thaumarchaeota dominated the top 20 OTUs. In the Voordelta, OTUs related to Colwellia, Shewanella and Psychrobium differentiated the oysters collected from a reef with those attached to rocks. Duikplaats were distinct for sulfur-oxidizers Sulfurimonas and sulfate-reducers from the Sva 0081 sediment group. Archaea were found mainly in sediments and the oyster associated microbiome, with greater abundance at the reef site, consisting mostly of Thaumarchaeota from the family Nitrosopumilaceae. The oyster free site displayed archaea in sediments only, and algal bloom indicator microorganisms from the Rhodobacteraceae, Flavobacteriaceae family and genus [Polaribacter] huanghezhanensis, in addition to the ascidian symbiotic partner, Synechococcus. This study suggests site specific microbiome shifts, influenced by the presence of oysters and the type of substrate.

Cryptic Behaviour of Juvenile Turbot Psetta maxima L.and European Flounder Platichthys flesus L.

The aim of this study was to examine the burying behaviour of hatchery-reared European flounder Platichthys flesus and turbot Psetta maxima, and whether conditioning on a sandy substrate would improve burying efficiency. Both species buried shortly after release on a sandy substrate. However, the study revealed interspecies differences;the flounder buried immediately after release, while the turbot buried gradually. No significant difference in burying efficiency was observed between na&iumlve and conditioned flounder and turbot. An effect of size on burial efficiency was observed for both flounder and turbot with a tendency for larger fish to bury more efficiently than smaller fish, despite previous conditioning. Size at settlement was found to be >2 cm for flounder and >3 cm for turbot.

Restoration of a Temperate Reef:Effects on the Fish Community

The extraction of large boulders from coastal reefs for construction of harbours and coastal protection has led to habitat degradation for local fish populations through the destruction of cavernous reefs and changes in macroalgal cover resulting from a loss of substrate. The temperate reef at L?s? Trindel in Kattegat, Denmark, has now been re-established with the aim of restoring the reef’s historical structure and function. The effects of the restoration on the local fish community are reported here. Fishing surveys using gillnets and fyke nets were conducted before the restoration (2007) and four years after the restoration of the reef (2012). Species of the family Labridae, which have a high affinity for rocky reefs, dominated both before and after the restoration. Commercially important species such as cod Gadus morhua, and saithe Pollachius virens, occurred infrequently in the catches in 2007 but were significantly more abundant in the catches in 2012. Cods were especially attracted to the shallow part of the reef that was restored by adding stones. For some species, such as ballan wrasse Labrus bergylta, and cod, the proportion of larger individuals increased after the restoration. The findings highlight the importance of reef habitats for fish communities and the need for their protection.

The biogeography of group sizes in humpback dolphins(Sousa spp.)

Humpback dolphins(Sousa spp.)are obligate shallow-water and resident species,and they typically live in fission–fusion societies composed of small-sized groups with changeable membership.However,we have scant knowledge of their behavioral ecology,starting with potential factors influencing inter-population variability of their group sizes.Here,we compiled a new global dataset of humpback dolphin group sizes based on 150 published records.Our data indicated an inter-specific consistency of group-living strategy among the 4 species in the Sousa genus,as these species preferred living in small-sized groups with a mean size of mostly no more than 10,a minimum size of single individual or small pairs,and a maximum size of several tens or≈100.In addition,we clearly showed the geographic variations in group sizes of humpback dolphins at a global scale.We found that the geographic variations in humpback dolphin group sizes were primarily associated with the latitude,sea surface temperature,and abundance.To conclude,our findings provide insights into social dynamics and socioecological trade-offs of humpback dolphins,and help better understand how these resident animals adapted to their shallow-water habitats from the perspectives of biogeography and socioecology.

Effects of low-oxygen conditions on embryo growth in the painted turtle,Chrysemys picta

Low-oxygen conditions(hypoxia;<21%O_(2))are considered unfavorable for growth;yet,embryos of many vertebrate taxa develop successfully in hypoxic subterranean environments.Although enhanced tolerance to hypoxia has been demonstrated in adult reptiles,such as in the painted turtle(Chrysemys picta),its effects on sensitive embryo life stages warrant attention.We tested the hypothesis that short-term hypoxia negatively affects growth during day 40 of development in C.picta,when O_(2) demands are highest in embryos.A brief,but severe,hypoxic event(5%O_(2) for 0.5 h)moderately affected embryo growth,causing a 13%reduction in mass(relative to a normoxic control).The same condition had no effect during day 27;instead,a nearly anoxic event(1%O_(2) for 72 h)caused a 5%mass reduction.All embryos survived the egg incubation period.Our study supports the assumption that reptilian embryos are resilient to intermittently low O_(2) in subterranean nests.Further work is needed to ascertain responses to suboptimal O_(2) levels while undergoing dynamic changes in developmental physiology.

全面实现全球可持续发展目标的黯淡前景和针对性行动

实施《2030年可持续发展议程》的时间框架已经过半,不同国家实现可持续发展目标(SDGs)的进展呈现明显差异.国家分类为提高政策效率和促进联合行动奠定了基础.本研究发展了基于SDGs表现的国家分类,进而分析不同类型国家SDGs间相互作用,比较不同类型国家获得的发展援助与实际需求的匹配情况.根据166个国家17项SDGs的表现可以将其划分为从“可持续发展水平最低但环境良好”到“可持续发展水平高但需要气候行动”的五种类型.这些国家类型中没有一种在所有SDG吐均表现出色,也没有一种能够在当前SDGs相互作用下最终实现所有目标.全球可持续发展的前景不容乐观,凸显了所有国家进行可持续转型的重要性和紧迫性,而优先考虑某些SDGs(如SDG 9,产业、创新和基础设施)是在可持续发展水平较低的国家事半功倍的途径.此外,全球发展援助需要与不同国家需求更加匹配,特别是在教育、能源、环境和供水与卫生等领域.研究明确了不同类型国家实现SDGs的关键机遇与挑战,有助于统筹国家层面相关可持续发展政策、促进更有针对性的国际协作,为推进全球SDGs的全面实现提供科学依据.