Harnessing eDNA metabarcoding to investigate fish community composition and its seasonal changes in the Oslo fjord.

In the face of global ecosystem changes driven by anthropogenic activities, effective biomonitoring strategies are crucial for mitigating impacts on vulnerable aquatic habitats. Time series analysis underscores a great significance in understanding the dynamic nature of marine ecosystems, especially amidst climate change disrupting established seasonal patterns. Focusing on Norway's Oslo fjord, our research utilises eDNA-based monitoring for temporal analysis of aquatic biodiversity during a one year period, with bi-monthly sampling along a transect. To increase the robustness of the study, a taxonomic assignment comparing BLAST+ and SINTAX approaches was done. Utilising MiFish and Elas02 primer sets, our study detected 63 unique fish species, including several commercially important species. Our findings reveal a substantial increase in read abundance during specific migratory cycles, highlighting the efficacy of eDNA metabarcoding for fish composition characterization. Seasonal dynamics for certain species exhibit clear patterns, emphasising the method's utility in unravelling ecological complexities. eDNA metabarcoding emerges as a cost-effective tool with considerable potential for fish community monitoring for conservation purposes in dynamic marine environments like the Oslo fjord, contributing valuable insights for informed management strategies.

Comparative effect of an essential oil mouthrinse on plaque, gingivitis and salivary Streptococcus mutans levels: a double blind randomized study.

An open, randomized, controlled study with two parallel treatment groups was done to evaluate the efficacy of a Lippia sidoides essential oil (EO) 1% mouthrinse compared with chlorhexidine 0.12% mouthrinse, applied two times daily for 1 week, in the treatment of dental plaque and gingivitis. Fifty-five patients were included in the study. The efficacy variables were the colony count of Streptococcus mutans from the stimulated saliva and periodontal indices on days 0, 7 and 30 after commencement of therapy. Twenty eight patients received chlorhexidine mouthrinse (Periogard((R))) and 27 Lippia sidoides essential oil mouthrinse (Cepakill((R))). The clinical and microbiological parameters were significantly reduced by both mouthrinses. No significant difference was seen between the two groups (p > 0.05). There was a significant reduction in the colony count of S. mutans in both groups (p < 0.05). Chlorhexidine treatment reduced more efficiently than L. sidoides, however, no statistical difference was seen, the efficacy of both groups was similar (p = 0.3). The results indicate that Chlorhexidine mouthrinse reduced plaque index, gingival bleeding and the number of CFU (colonies forming units) more efficiently than L. sidoides but did not reach statistical significance. This study demonstrated that Lippia sidoides EO mouthrinse is effective in reducing microbial plaque and gingival inflammation.