Free-living nematodes of Mediterranean ports: A mandatory contribution for their use in ecological quality assessment

Experimental and computational assessment of Antiparkinson Medication effects on meiofauna: Case study of Benserazide and Trihexyphenidyl

Two concentrations (6.25 and 1.25 mg/L) were used for two Parkinson's disease medications, Benserazide, and Trihexyphenidyl, to test their effects on the meiobenthic nematofauna. It is predicted that these highly hydrosoluble drugs will end up in marine environments. The results showed that both medications when added alone, induced (i) important changes in the numbers and (ii) taxonomic composition. The impact of Benserazide and Trihexyphenidyl was also reflected in the (iii) functional traits of nematofauna, with the most affected categories following exposure being the trophic group 1B, the clavate tails, the circular amphids, the c-p2 life history, and the body length of 1-2 mm. These results were supported by the molecular interactions of the studied drugs with both GLD-3 and SDP proteins of Caenorhabditis elegans. (iv) The mixtures of both drugs did not show any changes in the nematode communities, suggesting that no synergistic or antagonistic interactions exist between them.

Multi-benthic size approach to unveil different environmental conditions in a Mediterranean harbor area (Ancona, Adriatic Sea, Italy)

Harbors are hubs of human activity and are subject to the continuous discharge and release of industrial, agricultural, and municipal waste and contaminants. Benthic organisms are largely known to reflect environmental conditions they live in. Despite meio- and macrofauna interacting within the benthic system, they are ecologically distinct components of the benthos and as such may not necessarily respond to environmental conditions and/or disturbances in the same way. However, in a few field studies the spatial patterns of meio- and macrofauna have been simultaneously compared. In the present study, we assess the response and patterns in the abundance, diversity, and distribution of the two benthic size classes to the different environmental conditions they live in (i.e., sediment concentrations of selected trace metals and polycyclic aromatic hydrocarbons (PAHs); organic matter contents and grain size) characterizing the Ancona Harbor (Adriatic Sea). Meio- and macrofauna provided partially similar types of information depending on the indices used (univariate measures or community structure/species composition) and the different 'response-to-stress'. The community structure (i.e., taxa composition) of both benthic size components clearly showed differences among sampling stations located from inside to outside the harbor, reflecting the marked environmental heterogeneity and disturbance typically characterizing these systems. Notwithstanding, the univariate measures (i.e., meio- and macrofauna total abundance, diversity indices and equitability) didn't show similar spatial patterns. Meiofauna were likely to be more sensitive to the effects of environmental features and contaminants than macrofauna. Overall, trace metals and PAHs affected the community composition of the two benthic components, but only the meiofauna abundance and diversity were related to the environmental variables considered (i.e., quantity and quality of organic matter). Our results pinpoint the importance of studying both meio- and macrofauna communities, which could provide greater insight into the processes affecting the investigated area and reveal different aspects of the benthic ecosystems in response to harbor conditions.

Bioassessment of environmental quality based on taxonomic and functional traits of marine nematodes in the Bohai Sea, China

Free-living marine nematodes are valuable biological indicators for different environmental disturbances. Their taxonomic composition and functional traits often respond to environmental changes. In this study, marine nematodes, collected from the Bohai sea on the northeastern coast of China in 2014, were investigated in terms of their taxonomic composition and functional traits. Furthermore, the environmental quality of the investigated area was assessed based on nematode metrics. The studied nematode community showed spatial variation in taxonomic and functional composition, in response to changes in environmental variables such as sediment chlorophyll-a, phaeophytin-a, organic matter content, silt-clay content etc. Overall, high percentage of tolerant marine nematodes species or colonizers predominated, suggesting a disturbed environmental condition of the study area. Further results from the environmental quality assessment based on nematode metrics indicated a moderate quality status at the most investigated stations.

Short-term effects of trampling on intertidal Mytilus galloprovincialis beds

Human trampling represents one of the main anthropogenic pressures in the rocky intertidal. This habitat includes many ecosystem engineers such as mussels that provide biogenic habitat and multiple services. This research assessed potential impacts of human trampling on beds of the mussel, Mytilus galloprovincialis, on NW shores of Portugal. To test for direct effects of trampling on mussels and indirect effects on the associated assemblages, three treatments were applied: control (untouched beds), low and high intensity of trampling. Effects of trampling were dependent on the taxa. Thus, values of shell length of M. galloprovincialis were greater under the highest intensity of trampling while abundances of Arthropoda, Mollusca and Lasaea rubra showed the opposite pattern. Moreover, total number of taxa and abundances of Nematoda and Annelida showed higher values under low trampling intensity. The implications of these results to manage human use in areas with ecosystem engineers are discussed.