Assessment of interactive acoustic deterrent devices set on trammel nets to reduce dolphin-fishery interactions in the Northern Tyrrhenian Sea.

Dolphin-fishery interaction is a worldwide issue affecting dolphins through bycatch and fishers through catch or gear damages. Concerning the Mediterranean Sea, problematic interactions mainly occur between common bottlenose dolphin and small-scale fisheries. Acoustic Deterrent Devices such as pingers, are one of the most widespread measures used in attempts to face this issue. Therefore, the efficiency of interactive pingers (DiD01) in protecting the trammel nets from dolphin interactions was assessed in the Northern Tyrrhenian Sea. From March to October 2021, a total of 139 fishing trials using nets with pingers (TEST) and without pingers (CTRL), respectively n = 97 and n = 42, were carried out. Non-parametric statistic of the Catch per Unit Effort, comparing control and test nets, was not significantly different (p > 0.05) using catches weights (CPUEW) while it was significant (p < 0.01) considering the number of individuals (CPUEN). Moreover, richness and relative abundance of species resulted statistically higher in test nets (p < 0.05). This finding suggests that the absence of dolphin in the neighbourhood of fishing areas thanks to the use of pingers increases the diversity of target species. Catch damages caused by dolphins were statistically higher in nets without pinger than in nets with pinger (p < 0.05). No dolphin bycatch was recorded during fishing operations.

Relationship between wind and seagrass meadows in a non-tidal eutrophic lagoon studied by a Wave Exposure Model (WEMo).

The hydrodynamic action of wind and the distribution of biomass of seagrass meadows in a non-tidal eutrophic lagoon (Orbetello Lagoon, Tuscany, Italy) were analysed for correlations by simulation with a Wave Exposure Model (WEMo) on 5-year data series. WEMo and statistical analysis established a weak direct correlation between the areas that the model identified as being subject to resuspension and transport of sediment and those actually colonised by seagrass. A significant difference was found between surface and bottom hydrodynamics. The areas that the model identified as exposed to higher energy surface hydrodynamics proved to be inversely correlated with seagrass biomass. Multivariate statistical analysis ordered the model variables according to their relative importance. The model indicated the need for further study, demonstrating its utility for environmental management of eutrophic lagoons.

Two naphthalene degrading bacteria belonging to the genera Paenibacillus and Pseudomonas isolated from a highly polluted lagoon perform different sensitivities to the organic and heavy metal contaminants.

Two bacterial strains were isolated in the presence of naphthalene as the sole carbon and energy source from sediments of the Orbetello Lagoon, Italy, which is highly contaminated with both organic compounds and metals. 16S rRNA gene sequence analysis of the two isolates assigned the strains to the genera Paenibacillus and Pseudomonas. The effect of different contaminants on the growth behaviors of the two strains was investigated. Pseudomonas sp. ORNaP2 showed a higher tolerance to benzene, toluene, and ethylbenzene than Paenibacillus sp. ORNaP1. In addition, the toxicity of heavy metals potentially present as co-pollutants in the investigated site was tested. Here, strain Paenibacillus sp. ORNaP1 showed a higher tolerance towards arsenic, cadmium, and lead, whereas it was far more sensitive towards mercury than strain Pseudomonas sp. ORNaP2. These differences between the Gram-negative Pseudomonas and the Gram-positive Paenibacillus strain can be explained by different general adaptive response systems present in the two bacteria.