Impacts of organic enrichment on macrobenthic production, productivity, and transfer efficiency: What can we learn from a gradient of sewage effluents?

We studied the macrobenthic invertebrate biomass (B), production (P), productivity (P/B̅-ratio), and transfer efficiency (TE) influenced by sewage effluents discharge in a diffusion zone. Our results indicated a clear distribution pattern of macrofauna communities along the sewage discharge gradient where biological factors (B, P, P/B̅, and TE) were driven by changes observed in community structure, composition, and the influence of environmental variables. The lowest B, P, and P/B̅ were observed at the stations sampled close to the pipelines. Abundance, biomass, production, and productivity increased with increasing distance from the pipelines toward stations placed at 100 m distance and then decreased toward the stations placed at >200 m, where there was a negative relationship between TE and B of macrofauna at sampling stations. Overall, there was a clear influence of the sewage discharge on macrofauna communities, but surrounding environment was influenced moderately by organic impact and discharges had no negative impacts.

Toxicity of Mediterranean Scyphomedusae: An Overview.

Following in-depth analysis and examination, jellyfish toxins have been found to consist of a mixture of proteins, carbohydrates, and other non-proteinaceous components. What remains to be clarified is the specific chemical nature of jellyfish toxins due to their heat lability. This paper reviews current knowledge of the toxic properties of the most common Mediterranean scyphozoans (A. aurita, C. hysoscella, C. tuberculata, P. noctiluca, R. pulmo) and the activity of their venom.