Phytoplankton are the basic component of the aquatic food chain. To date phytoplankton communities from the coastal waters of Bangladesh have received only little scientific attention. Consequently, the abundance and community composition of phytoplankton and their relationship with some abiotic factors were studied during December 2014 to August 2015 in the Reju Khal estuary of the south-eastern coast of Bangladesh. Marked seasonal differences were observed for all of the measured abiotic factors. The density of the phytoplankton cells ranged between 9408 and 21,964 cells L⁻¹ and had significant differences among seasons. Over all seasonal samples, 27 genera were identified of which Biddulphia was found to be the most contributory one (13.6%) followed by Coscino discus (7.9%) and Nostoc (7.8%). Marked seasonal differences in the community structure of phytoplankton were confirmed by the multivariate analyses. Further, phytoplankton populations had strong positive correlations with pH, salinity, total dissolve solids, and Secchi depth.

Zostera marina (eelgrass) is a widespread seagrass species that forms diverse and productive habitats along coast lines throughout much of the northern hemisphere. The present study investigated the microbial consortia of Z. marina growing at Futtsu clam-digging beach, Chiba prefecture, Japan. The following environmental samples were collected: sediment, seawater, plant leaves, and the root-rhizome. Sediment and seawater samples were obtained from three sampling points: inside, outside, and at the marginal point of the eelgrass bed. The microbial composition of each sample was analyzed using 16S ribosomal gene amplicon sequencing. Microbial communities on the dead (withered) leaf surface markedly differed from those in sediment, but were similar to those in seawater. Eelgrass leaves and surrounding seawater were dominated by the bacterial taxa Rhodobacterales (Alphaproteobacteria), whereas Rhodobacterales were a minor group in eelgrass sediment. Additionally, we speculated that the order Sphingomonadales (Alphaproteobacteria) acts as a major degrader during the decomposition process and constantly degrades eelgrass leaves, which then spread into the surrounding seawater. Withered eelgrass leaves did not accumulate on the surface sediment because they were transported out of the eelgrass bed by wind and residual currents unique to the central part of Tokyo Bay.

Zostera marina (eelgrass) is classified as one of the marine angiosperms and is widely distributed throughout much of the Northern Hemisphere. The present study investigated the microbial community structure and diversity of Z. marina growing in Futtsu bathing water, Chiba prefecture, Japan. The purpose of this study was to provide new insight into the colonization of eelgrass leaves by microbial communities based on leaf age and to compare these communities to the root-rhizome of Z. marina, and the surrounding microenvironments (suspended particles, seawater, and sediment). The microbial composition of each sample was analyzed using 16S ribosomal gene amplicon sequencing. Each sample type was found to have a unique microbial community structure. Leaf-attached microbes changed in their composition depending on the relative age of the eelgrass leaf. Special attention was given to a potential microbial source of leaf-attached microbes. Microbial communities of marine particles looked more like those of eelgrass leaves than those of water samples. This finding suggests that leaf-attached microbes were derived from suspended particles, which could allow them to go back and forth between eelgrass leaves and the water column.

Human activities significantly influence the changes in wildlife habitats and biodiversity, highlighting the necessity to enhance public knowledge, perceptions, and practices (KPP) to mitigate their consequences. Previous research suggests that many people in Bangladesh do not consider wildlife and biodiversity conservation a crucial issue. However, enhancing their KPP could be essential in developing effective and sustainable conservation efforts in Bangladesh. So, the current study aimed to evaluate the public’s KPP of wildlife conservation and biodiversity management in Bangladesh. A total of 3060 individuals’ data were collected from various sociodemographic backgrounds using a structured questionnaire followed by statistical analyses including Pearson’s chi-square, Spearman’s correlation, and logistic regression analysis, which were performed to assess the correlations and trends among variables using STATA and SPSS. The results revealed a significant heterogeneity in KPP across different sociodemographic groups. Importantly, the younger respondents (ages 21–30) indicated a high level of KPP, and respondents without formal education and belonging to older ages demonstrated markedly low levels of KPP. In the country’s divisional levels, respondents from Khulna and Rangpur revealed the highest and lowest KPP levels, respectively. Our study also revealed that students represented the major occupational demographic and displayed moderate levels of KPP. Notably, respondents highlighted the decline or absence of several wild animal species, including black bears, deer, vultures, wild cats, hanuman monkeys, and rhesus monkeys, from their local areas over the past decades. Public opinion on wildlife protection revealed 78.6% and 73.4% disapproving of hunting rejection and wildlife trading, respectively. Nonetheless, a lack of knowledge remained, as 16.89% of respondents were unaware of measures to alleviate human-wildlife conflict. The correlation analysis indicated a favorable association among KPP components, especially between knowledge and perception (correlation coefficient = 0.438), underscoring the essential influence of awareness on conservation actions. This study offers critical insights for developing interventions to enhance KPP among local communities and stakeholders, hence promoting sustainable wildlife conservation and biodiversity management in Bangladesh. Taken together, the findings provide baseline data for safeguarding biodiversity and fostering long-term wildlife sustainability in Bangladesh.

Seagrass meadows produce organic carbon and deposit it on the seabed through the decaying process. Microbial activity is closely related to the process of eelgrass death and collapse. We investigated the microbial community structure of eelgrass during the eelgrass decomposition process by using a microcosm containing raw seawater and excised eelgrass leaves collected from a Zostera marina bed in Futtsu, Chiba Prefecture, Japan. The fast-growing microbes (i.e., Alphaproteobacteria, Gammaproteobacteria, and Flavobacteriia) rapidly adhered to the eelgrass leaf surface and proliferated in the first two weeks but gradually decreased the relative abundance as the months moved on. On the other hand, the slow-growing microbes (i.e., Cytophagia, Anaerolineae, Thaumarchaeota, and Actinobacteria) became predominant over the eelgrass surface late in the culture experiment (120, 180 days). The fast-growing groups of Gammaproteobacteria and Flavobacteriia appear to be closely related to the initial decomposition of eelgrass, especially the rapid decomposition of leaf-derived biopolymers. Changes in nitrogen content due to the bacterial rapid consumption of readily degradable organic carbon induced changes in the community structure at the early stage of eelgrass decomposition. In addition, shifts in the C/N ratio were driven by microbial community changes during later decomposition phases.