Kelp beds as coastal protection: wave attenuation of Ecklonia radiata in a shallow coastal bay

A culture-independent approach, supervised machine learning, and the characterization of the microbial community composition of coastal areas across the Bay of Bengal and the Arabian Sea

BACKGROUND

Coastal areas are subject to various anthropogenic and natural influences. In this study, we investigated and compared the characteristics of two coastal regions, Andhra Pradesh (AP) and Goa (GA), focusing on pollution, anthropogenic activities, and recreational impacts. We explored three main factors influencing the differences between these coastlines: The Bay of Bengal's shallower depth and lower salinity; upwelling phenomena due to the thermocline in the Arabian Sea; and high tides that can cause strong currents that transport pollutants and debris.

RESULTS

The microbial diversity in GA was significantly higher than that in AP, which might be attributed to differences in temperature, soil type, and vegetation cover. 16S rRNA amplicon sequencing and bioinformatics analysis indicated the presence of diverse microbial phyla, including candidate phyla radiation (CPR). Statistical analysis, random forest regression, and supervised machine learning models classification confirm the diversity of the microbiome accurately. Furthermore, we have identified 450 cultures of heterotrophic, biotechnologically important bacteria. Some strains were identified as novel taxa based on 16S rRNA gene sequencing, showing promising potential for further study.

CONCLUSION

Thus, our study provides valuable insights into the microbial diversity and pollution levels of coastal areas in AP and GA. These findings contribute to a better understanding of the impact of anthropogenic activities and climate variations on biology of coastal ecosystems and biodiversity.

Shallow-Water Bryozoan Communities in a Glacier Fjord of West Svalbard, Norway: Species Composition and Effects of Environmental Factors

Despite significant research efforts focused on benthic assemblages in West Spitsbergen, there is a lack of knowledge regarding the shallow water bryozoan communities in Grønfjorden, a glacier fjord belonging to the Isfjorden system, Norway. Here, we studied species composition, richness, distribution, and biomass of bryozoans in the intertidal and upper subtidal zones of Grønfjorden in summer. We found 62 bryozoan species, among which Celleporella hyalina (Linnaeus, 1767), Harmeria scutulata (Busk, 1855), and Tegella arctica (d'Orbigny, 1853) were most prevalent while the highest contributions to the total biomass were registered for Eucratea loricata (d'Orbigny, 1853), Tricellaria gracilis (Van Beneden, 1848), Turbicellepora incrassata (Lamarck, 1816), and Tricellaria ternata (Ellis and Solander, 1786). Alpha-diversity varied from 1 to 50 averaging 15.1 ± 2.6 species. Bryozoan biomass ranged from 0.008 to 10.758 g m^-2 with a mean value of 2.67 g m^-2 being lower than in the central and northern parts of the Barents Sea. For the first time, we registered the presence of the circumpolar bryozoan Amathia arctica in Svalbard waters probably as a result of stronger advection of Atlantic water into the fjord. Cluster analysis revealed two groups, mainly composed of stations in colder and warmer waters. A relatively high proportion of outlying stations reflected habitat heterogeneity in Grønfjorden. Redundancy analysis indicated that bryozoan diversity and biomass were strongly negatively associated with temperature. A positive relationship was found between bryozoan biomass and the proportional contribution of macrophytes to a pool of substrates. Our study provides a reference point for further monitoring of changing marine ecosystems at high latitudes.

Current Insights into the Molecular Mode of Action of Seaweed-Based Biostimulants and the Sustainability of Seaweeds as Raw Material Resources

Natural biostimulants, such as seaweed extracts, can stimulate plant growth and development in both model and crop plants. Due to the increasing demands for their use in agriculture, it is crucial to ensure the sustainability of the sources from which they are produced. Furthermore, some seaweed extracts were recently shown to prime and protect from adverse environmental factors such as drought, salinity and extreme temperatures, as well as from oxidative stress. The molecular mode of action of these biostimulants has still not been fully elucidated, but there has been significant progress in this direction in the last years. Firstly, this review examines the sustainability aspects of harvesting seaweed resources as raw materials for manufacturing biostimulants and provides an overview of the regulatory landscape pertaining to seaweed-based biostimulants. The review then summarises the recent advances in determining the genetic and molecular mechanisms activated by seaweed-based biostimulants, their influence on transcriptome reconfiguration, metabolite adjustment, and ultimately stress protection, improved nutrient uptake, and plant growth and performance. This knowledge is important for deciphering the intricate stress signalling network modulated by seaweed-based biostimulants and can aid in designing molecular priming technologies for crop improvement.

The gathering storm: optimizing management of coastal ecosystems in the face of a climate-driven threat

BACKGROUND

The combination of rising sea levels and increased likelihood of extreme storm events poses a major threat to our coastlines and as a result, many ecosystems recognized and valued for their important contribution to coastal defence face increased damage from erosion and flooding. Nevertheless, only recently have we begun to examine how plant species and communities, respond to, and recover from, the many disturbances associated with storm events.

SCOPE

We review how the threats posed by a combination of sea level rise and storms affects coastal sub-, inter- and supra-tidal plant communities. We consider ecophysiological impacts at the level of the individual plant, but also how ecological interactions at the community level, and responses at landscape scale, inform our understanding of how and why an increasing frequency and intensity of storm damage are vital to effective coastal management. While noting how research is centred on the impact of hurricanes in the US Gulf region, we take a global perspective and consider how ecosystems worldwide (e.g. seagrass, kelp forests, sand dunes, saltmarsh and mangroves) respond to storm damage and contribute to coastal defence.

CONCLUSIONS

The threats posed by storms to coastal plant communities are undoubtedly severe, but, beyond this obvious conclusion, we highlight four research priority areas. These call for studies focusing on (1) how storm disturbance affects plant reproduction and recruitment; (2) plant response to the multiple stressors associated with anthropogenic climate change and storm events; (3) the role of ecosystem-level interactions in dictating post-disturbance recovery; and (4) models and long-term monitoring to better predict where and how storms and other climate change-driven phenomena impact coastal ecosystems and services. In so doing, we argue how plant scientists must work with geomorphologists and environmental agencies to protect the unique biodiversity and pivotal contribution to coastal defence delivered by maritime plant communities.