Effects of vessel traffic on relative abundance and behaviour of cetaceans : the case of the bottlenose dolphins in the Archipelago de La Maddalena, north-western Mediterranean sea

Acknowledgements This study was part of the Tursiops Project of the Dolphin Research Centre of Caprera, La Maddalena. Financial and logistical support was provided by the Centro Turistico Studentesco (CTS) and by the National Park of the Archipelago de La Maddalena. We thank the Natural Reserve of Bocche di Bonifacio for the support provided during data collection. The authors thank the numerous volunteers of the Caprera Dolphin Research Centre and especially Marco Ferraro, Mirko Ugo, Angela Pira and Maurizio Piras whose assistance during field observation and skills as a boat driver were invaluable.Peer reviewedPostprin

Interaction between bottlenose dolphin (Tursiops truncatus) and trammel nets in the Archipelago de La Maddalena, Italy

Peer reviewedPublisher PD

Microplastics in grey seal (Halichoerus grypus) intestines: Are they associated with parasite aggregations?

Embargo until 28 June 2021Between 2012 and 2015, 13 grey seals were recovered from trammel nets targeting monkfish and rays off the south coast of Ireland. Incidence and distribution of microplastics were investigated along the intestines of bycaught seals. No macrodebris items were found, whereas microplastics were detected in all seals. A total of 363 microplastics items were identified (85% fibers, 14% fragments, 1% films). Estimation of microplastic ingestion based on prey ingestion (245 particles) was lower than the observed data. Acantocephala parasites (n = 1543) were found in 12 seals, with an average of 74.5 ± 67.7 parasites per seal. Distribution of microplastics varied between seals, although microplastics tended to accumulate in areas where more parasites were aggregated; however, there was no significant relationship between the number of parasites and microplastics was found. Seals recovered from nets appear to be a good source to monitor the incidence of microplastic pollution within the coastal food webs.acceptedVersio

Another top predator in the list: microplastics in Mediterranean Monk Seals.

Mediterranean Sea has been considered one of the areas with highest density of plastics. This is a particular Sea Region where one of the most critically marine mammal species, the Mediterranean monk seal, inhabit. The incidence of plastics, including microplastics, in this species has not been investigate yet. In this study we present the fi rst results about incidence of microplastics in this predator through scat analysis. Scat samples from north Adriatic (Istria- Croatia, n=4) and south Tyrrhenian (Sicily-Italy, n=4) seas were collected and analyzed for both microplastics and dietary investigations. Microplastic separation and identifi cation was carried out following previous methodology adapted for scat samples. In all samples, only demersal fi sh was identifi ed, but only 30% of the samples contained microplastics (fi bers). Although the study was carried out with limited sample size, the trophic transfer possibility is discussed. In addition, we underline the importance of this information for an endangered mammal such as the Mediterranean monk seal, and the use of scats for the fi rst time for this species

Another top predator in the list: microplastics in Mediterranean Monk Seals.

Mediterranean Sea has been considered one of the areas with highest density of plastics. This is a particular Sea Region where one of the most critically marine mammal species, the Mediterranean monk seal, inhabit. The incidence of plastics, including microplastics, in this species has not been investigate yet. In this study we present the fi rst results about incidence of microplastics in this predator through scat analysis. Scat samples from north Adriatic (Istria- Croatia, n=4) and south Tyrrhenian (Sicily-Italy, n=4) seas were collected and analyzed for both microplastics and dietary investigations. Microplastic separation and identifi cation was carried out following previous methodology adapted for scat samples. In all samples, only demersal fi sh was identifi ed, but only 30% of the samples contained microplastics (fi bers). Although the study was carried out with limited sample size, the trophic transfer possibility is discussed. In addition, we underline the importance of this information for an endangered mammal such as the Mediterranean monk seal, and the use of scats for the fi rst time for this species

Influence of macrofaunal assemblages and environmental heterogeneity on microphytobenthic production in experimental systems

Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, rapid response times and the well-understood effects of macrofauna on sediment processes. Here, the influence of heterogeneity on microphytobenthic production in synthetic estuarine assemblages is examined. Heterogeneity was created by enriching patches of sediment with detrital algae (Enteromorpha intestinalis) to provide a source of allochthonous organic matter. A gradient of species density for four numerically dominant intertidal macrofauna (Hediste diversicolor, Hydrobia ulvae, Corophium volutator, Macoma balthica) was constructed, and microphytobenthic biomass at the sediment surface was measured. Statistical analysis using generalized least squares regression indicated that heterogeneity within our system was a significant driving factor that interacted with macrofaunal density and species identity. Microphytobenthic biomass was highest in enriched patches, suggesting that nutrients were obtained locally from the sediment–water interface and not from the water column. Our findings demonstrate that organic enrichment can cause the development of heterogeneity which influences infaunal bioturbation and consequent nutrient generation, a driver of microphytobenthic production