Biomagnification and temporal trends (1990-2021) of perfluoroalkyl substances in striped dolphins (Stenella coeruleoalba) from the NW Mediterranean sea.

Poly- and Perfluoroalkyl Substances (PFAS) are a well-known class of pollutants which can bioaccumulate and biomagnify with a vast majority being highly persistent. This study aims to determine the biomagnification rates of PFAS in sexually mature striped dolphins and to assess temporal trends on PFAS concentrations over the past three decades (1990-2021) in the North-Western Mediterranean Sea. Thirteen and 17 of the 19 targeted PFAS were detected in the samples of the dolphins' digestive content and liver, respectively, at concentrations ranging between 43 and 1609 ng/g wet weight, and 254 and 7010 ng/g wet weight, respectively.

Concentrations of bisphenols and phthalate esters in the muscle of Mediterranean striped dolphins (Stenella coeruleoalba).

Bisphenols (BPs) and phthalate esters (PAEs) are important compounds for the plastics industry, also called "everywhere chemicals" due to their ubiquity in daily use products. Both chemical groups are well-known environmental contaminants, whose presence has been reported in all environmental compartments, and whose effects, mainly associated to endocrine disruption, are detrimental to living organisms. Cetaceans, due to their long life-span, low reproduction rate and high position in the trophic web, are especially vulnerable to the effects of contaminants.

Intrapopulation and temporal differences of phthalate concentrations in North Atlantic fin whales (Balaenoptera physalus).

The fin whale (Balaenoptera physalus) is a migratory filter-feeding species that is susceptible to ingest plastics while lunge feeding across the oceans. Plastic additives, such as phthalates, are compounds that are added to plastics to give them specific characteristics, such as flexibility. These so-called plasticizers are currently raising major concern because of their potential adverse effects on marine fauna.

Ingestion of synthetic particles by fin whales feeding off western Iceland in summer.

In this study we aim to assess the daily ingestion rates of synthetic particles by the fin whales (Balaenoptera physalus) that feed off the western coast of Iceland. To do so, we collected and analysed samples from the stomach content of 25 fin whales, consisting solely of northern krill (Meganyctiphanes norvegica). The particles found consisted of fibres and fragments, mainly blue, black and red, with an average size of 1.

Automatic detection and quantification of floating marine macro-litter in aerial images: Introducing a novel deep learning approach connected to a web application in R.

The threats posed by floating marine macro-litter (FMML) of anthropogenic origin to the marine fauna, and marine ecosystems in general, are universally recognized. Dedicated monitoring programmes and mitigation measures are in place to address this issue worldwide, with the increasing support of new technologies and the automation of analytical processes. In the current study, we developed algorithms capable of detecting and quantifying FMML in aerial images, and a web-oriented application that allows users to identify FMML within images of the sea surface.

Floating marine macro litter: Density reference values and monitoring protocol settings from coast to offshore. Results from the MEDSEALITTER project.

Monitoring Floating Marine Macro Litter (FMML) is a global priority, stressed within international programs, and regulated for the European Seas by the Marine Strategy Framework Directive. Although some well-defined common protocols exist for the assessment of beach litter and ingested litter, methodologies for FMML monitoring still vary, leading to some inconsistent results and hampering the global assessment of this threat. Within the MEDSEALITTER project (2016-2019), field experiments were implemented to define optimal monitoring parameters for FMML visual monitoring at different spatial scales, by assessing the influence of platform speed, strip width, observers experience, weather conditions, and litter size on its detectability.

Using Boops boops (osteichthyes) to assess microplastic ingestion in the Mediterranean Sea.

This study assesses microplastic ingestion in Boops boops at different geographical areas in the Mediterranean Sea. A total of 884 fish were caught at 20 coastal sites in Spain, France, Italy and Greece and analyzed using a common methodological protocol. Microplastics were found in 46.

Floating marine macro-litter in the North Western Mediterranean Sea: Results from a combined monitoring approach.

The aim of the present study was twofold: (i) to validate the drone methodology for floating marine macro-litter (FMML) monitoring, by comparing the results obtained through concurrent drone surveys and visual observations from vessels, and (ii) to assess FMML densities along the North Western Mediterranean Sea using the validated drone surveys. The comparison between monitoring techniques was performed based on 18 concurrent drone/vessel transects. Similar densities of FMML were detected through the two methods (16 items km from the drone method vs 19 items km from the vessel-based visual method).

Assessment of organophosphate flame retardants in Mediterranean Boops boops and their relationship to anthropization levels and microplastic ingestion.

Plastic litter pollution is increasing in the seas and oceans worldwide, raising concern on the potential effects of plasticizer additives on marine fauna. In this study, muscle samples of 30 bogues (Boops boops; Linneaus, 1758) from the North Western Mediterranean Sea were analysed to assess the concentrations of 19 organophosphate flame retardant (OPFR) compounds and to inspect any relationship with microplastic ingestion and relative levels of anthropization. Out of the 19 OPFRs analysed, 6 compounds were detected, being tri-n-butyl phosphate (TNBP), 2-ethylhexyldiphenyl phosphate (EHDPP) and triphenylphosphine oxide (TPPO) the most abundant.

Who's better at spotting? A comparison between aerial photography and observer-based methods to monitor floating marine litter and marine mega-fauna.

Pollution by marine litter is raising major concerns due to its potential impact on marine biodiversity and, above all, on endangered mega-fauna species, such as cetaceans and sea turtles. The density and distribution of marine litter and mega-fauna have been traditionally monitored through observer-based methods, yet the advent of new technologies has introduced aerial photography as an alternative monitoring method. However, to integrate results produced by different monitoring techniques and consider the photographic method a viable alternative, this 'new' methodology must be validated.

Strontium in fin whale baleen: A potential tracer of mysticete movements across the oceans?

Strontium is a metal broadly distributed in oceanic waters, where its concentrations follow gradients mainly driven by oceanographic and biological factors. Studies on terrestrial vertebrates show that Sr can accumulate in mammalian hair in amounts mainly related to the external environment, a property that has been scarcely investigated in aquatic mammals. Cetaceans are marine mammals whose skin is generally hairless, but the species belonging to the mysticete group feed through a filtering apparatus made of keratinous baleen plates that, like hair, grow continuously.

Bone as a surrogate tissue to monitor metals in baleen whales.

Metals are massively deposited in the marine environment through direct emissions or atmospheric dry and wet depositions, a process since long enhanced by human activities. Metal contamination in the marine organisms has been increasingly investigated, but most research focuses on few tissues, elements and species considered indicative. Baleen whales have been scarcely studied in this respect.

The fin whale, a marine top consumer, exposes strengths and weaknesses of the use of fluoride as ecological tracer.

Fluoride is retained in bone tissues of animals and its availability in the environment varies between regions according to natural and anthropogenic sources. These properties suggest this element as a suitable tracer of origin, distribution or movements of animals. In marine environments, krill builds-up fluoride concentrations that are transferred to its predators.

Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis).

From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina) and another off central Argentina (Peninsula Valdés).

Stable isotopes provide insight into population structure and segregation in eastern North Atlantic sperm whales.

In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur.