Strandings of NE Atlantic gorgonians

Northeast coral gardens provide vital breeding and feeding habitats for fishes of conservation and commercial importance. Such habitats are increasingly at risk of destruction as a result of over fishing, ocean warming, acidification and marine litter.

A key cause for concern regarding the vulnerability of coral gardens to damage from any source is their slow growth rate, and thereby their ability to recover from damage. Hence protected areas are being put in place, which exclude the use of towed demersal fishing gear.

Citizen scientists observed that gorgonian coral (Pink Sea Fans) skeletons were stranding on beaches entangled in marine debris (sea fangles) across southwest England. Further, SCUBA divers reported that gorgonian corals were being caught up and damaged in lost fishing gear and other marine litter.

To determine the cause of the damage to coral gardens, sea fangles were collected and analysed.

The sea fangles were made up of a diverse range of litter from fishing and domestic sources, however, the majority comprised of fishing gear (P < 0.05).

Marine Protected Areas can protect coral gardens from direct fishing pressure, but risks still remain from ghost fishing pressure, demonstrating the need for sources of litter into the environment to be reduced and existing litter removed.

The EU Marine Strategy Framework Directive (MSFD) outlines targets for marine litter by 2020. This study highlights the importance of adhering to the MSFD and/or creating more ambitious regulation if the UK re-write existing legislation following BREXIT.

E.V. Sheehan, A. Rees, D. Bridger, T. Williams, J.M. Hall-Spencer, Biological Conservation, Volume 209, May 2017, Pages 482–487

The article

The uptake of macroplastic & microplastic by demersal & pelagic fish in the Northeast Atlantic around Scotland

This study reports plastic ingestion in various fish found from coastal and offshore sites in Scottish marine waters. Coastal samples consisted of three demersal flatfish species (n = 128) collected from the East and West coasts of Scotland. Offshore samples consisted of 5 pelagic species and 4 demersal species (n = 84) collected from the Northeast Atlantic. From the coastal fish sampled, 47.7% of the gastrointestinal tracts contained macroplastic and microplastic. Of the 84 pelagic and demersal offshore fish, only 2 (2.4%) individuals from different species had ingested plastic identified as a clear polystyrene fibre and a black polyamide fibre. The average number of plastic items found per fish from all locations that had ingested plastic was 1.8 (± 1.7) with polyamide (65.3%), polyethylene terephthalate (14.4%) and acrylic (14.4%) being the three most commonly found plastics. This study adds to the existing data on macroplastic and microplastic ingestion in fish species.

Fionn Murphy, Marie Russell, Ciaran Ewins, Brian Quinn, Marine Pollution Bulletin, Available online 10 July 2017, In Press

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Risk assessment reveals high exposure of sea turtles to marine debris in French Mediterranean and metropolitan Atlantic waters

Debris impact on marine wildlife has become a major issue of concern. Mainy species have been identified as being threatened by collision, entanglement or ingestion of debris, generally plastics, which constitute the predominant part of the recorded marine debris. Assessing sensitive areas, where exposure to debris are high, is thus crucial, in particular for sea turtles which have been proposed as sentinels of debris levels for the Marine Strategy Framework Directive and for the Unep-MedPol convention. Our objective here was to assess sea turtle exposure to marine debris in the 3 metropolitan French fronts. Using aerial surveys performed in the Channel, the Atlantic and the Mediterranean regions in winter and summer 2011–2012, we evaluated exposure areas and magnitude in terms of spatial overlap, encounter probability and density of surrounding debris at various spatial scales. Major overlapping areas appeared in the Atlantic and Mediterranean fronts, concerning mostly the leatherback and the loggerhead turtles respectively. The probability for individuals to be in contact with debris (around 90% of individuals within a radius of 2 km) and the density of debris surrounding individuals (up to 16 items with a radius of 2 km, 88 items within a radius of 10 km) were very high, whatever the considered spatial scale, especially in the Mediterranean region and during the summer season. The comparison of the observed mean debris density with random distribution suggested that turtles selected debris areas. This may occur if both debris and turtles drift to the same areas due to currents, if turtles meet debris accidentally by selecting high food concentration areas, and/or if turtles actively seek debris out, confounding them with their preys. Various factors such as species-specific foraging strategies or oceanic features which condition the passive diffusion of debris, and sea turtles in part, may explain spatio-temporal variations in sensitive areas. Further research on exposure to debris is urgently needed. Empirical data on sea turtles and debris distributions, such as those collected aerially, are essential to better identify the location and the factors determining risks.

Gaëlle Darmon, Claude Miaud, Françoise Claro, Ghislain Doremus, François Galgani, Deep Sea Research Part II: Topical Studies in Oceanography, Volume 141, July 2017, Pages 319-328

The article

Plastic ingestion in oceanic-stage loggerhead sea turtles (Caretta caretta) off the North Atlantic subtropical gyre

Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1–5 mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83 ± 6.09 (± SE) per individual, corresponding to a mean dry mass of 1.07 ± 0.41 g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic.

Christopher K. Pham, Yasmina Rodríguez, Axelle Dauphin and al., Marine Pollution Bulletin, Available online 9 June 2017, In Press

The article

Plastics in the North Atlantic garbage patch: A boat-microbe for hitchhikers and plastic degraders

Plastic is a broad name given to different polymers with high molecular weight that impact wildlife. Their fragmentation leads to a continuum of debris sizes (meso to microplastics) entrapped in gyres and colonized by microorganisms. In the present work, the structure of eukaryotes, bacteria and Archaea was studied by a metabarcoding approach, and statistical analysis associated with network building was used to define a core microbiome at the plastic surface. Most of the bacteria significantly associated with the plastic waste originated from non-marine ecosystems, and numerous species can be considered as hitchhikers, whereas others act as keystone species (e.g., Rhodobacterales, Rhizobiales, Streptomycetales and Cyanobacteria) in the biofilm. The chemical analysis provides evidence for a specific colonization of the polymers. Alphaproteobacteria and Gammaproteobacteria significantly dominated mesoplastics consisting of poly(ethylene terephthalate) and polystyrene. Polyethylene was also dominated by these bacterial classes and Actinobacteria. Microplastics were made of polyethylene but differed in their crystallinity, and the majorities were colonized by Betaproteobacteria. Our study indicated that the bacteria inhabiting plastics harboured distinct metabolisms from those present in the surrounding water. For instance, the metabolic pathway involved in xenobiotic degradation was overrepresented on the plastic surface.

Debroas Didier, Mone Anne, Ter Halle Alexandra, Science of The Total Environment, Volumes 599–600, 1 December 2017, Pages 1222–1232

The article

Quantification and characterization of microplastics in blue mussels (Mytilus edulis): protocol setup and preliminary data on the contamination of the French Atlantic coast

Microplastics (MPs) constitute a main environmental issue due to their threat to marine organisms and so far to humans. The lack of a fast standard protocol in MP isolation and identification from living organisms bring to challenge for the science. In this paper, an optimized protocol using potassium hydroxide 10% (KOH 10%; m/v) for digestion of mussel soft tissues (Mytilus edulis) and multi-steps of sedimentation has been developed. Efficiency higher than 99.9% of organic and mineral matter elimination was shown by application on mussels sampled on the French Atlantic coast. The identification of MPs was performed by FTIR microscopy straight on the filter and the whole analysis can be compatible with a routine goal. Fourteen MPs of four different chemical natures were found and identified in 5 pools of 3 sampled mussels. Their size ranged from 30 to 200 μm. Further investigations are now needed to evaluate the potential risk of such particles within this marine bivalve species and other filter feeders.

Nam Ngoc Phuong, Aurore Zalouk-Vergnoux, Abderrahmane Kamari,Catherine Mouneyrac, Frederic Amiard, Laurence Poirier, Fabienne Lagarde, Environ Sci Pollut Res (April 2017), online first, pages 1-10

The article

Marine litter on the seafloor of the Faial-Pico Passage, Azores Archipelago

Plastic pollution in the marine environment attracts much attention from both researchers and the general public. Plastic items and other debris are commonly observed everywhere in the ocean, from the surface down to the deep ocean floor. In this study, we analysed 45.2 km of video footage, collected during 56 transects surveying the seafloor of the Faial-Pico Passage in order to quantify the abundance of marine litter and its interactions with benthic fauna. The footage was collected by a Remotely Operated Vehicle (ROV) and a manned submersible at depths ranging between 40 and 525 m. The mean litter density in the passage was 0.26 ± 0.03 items·100 m− 1 (± SE) and was significantly higher between 151 and 250 m compared to other depth strata. Overall, derelict fishing gear, mostly made of plastic, were the most common objects found on the seafloor, representing 64% of all items. Although we observed few evidence of direct deleterious effects by the litter, interactions with fauna were observed in more than half of the items. This study makes an important contribution in quantifying the abundance of marine litter on the seafloor of the Azores. The location of the Faial-Pico Passage, close to shore, makes it an appropriate site for long-term monitoring of litter on the seafloor and evaluate the efficiency of upcoming public policies aimed at reducing litter input into the oceans.

Yasmina Rodríguez, Christopher K. Pham, Marine Pollution Bulletin, Volume 116, Issues 1–2, 15 March 2017, Pages 448–453

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