Plastic Debris Occurrence, Convergence Areas and Fin Whales Feeding Ground in the Mediterranean Marine Protected Area Pelagos Sanctuary: A Modeling Approach

Maria Cristina Fossi,Jean-Noël Druon,Simonepietro Canese,Matteo Baini,Sabina Airoldi,Cristina Panti,Tommaso Campani,Chiara Lapucci,François Galgani,Letizia Marsili,Stefano Taddei,Maria Fattorini,Carlo Brandini,Teresa Romeo

doi:10.3389/fmars.2017.00167

Abstract

The Mediterranean Sea is greatly affected by marine litter. In this area, research on the impact of plastic debris (including microplastics) on biota, particularly large filter-feeding species such as the fin whale (Balaenoptera physalus), is still in its infancy. We investigated the possible overlap between microplastic, mesoplastic and macrolitter accumulation areas and the fin whale feeding grounds in in a pelagic Specially Protected Area of Mediterranean Importance (SPAMI): the Pelagos Sanctuary. Models of ocean circulation and fin whale potential habitat were merged to compare marine litter accumulation with the presence of whales. Additionally, field data on microplastics, mesoplastics and macrolitter abundance and cetacean presence were simultaneously collected. The resulting data were compared, as a multi-layer, with the simulated distribution of plastic concentration and the whale habitat model. These data showed a high occurrence of microplastics (mean: 0.082 items/m2, STD ± 0.079 items/m2) spatial distribution agreed with our modelling results. Areas with high microplastic density significantly overlapped with areas of high macroplastic density. The most abundant polymer detected in all the sampling sites was polyethylene (PE), suggesting fragmentation of larger packaging items as the primary source. To our knowledge, this is the first study in the Pelagos Sanctuary in which the simulated microplastic distribution has been confirmed by field observations. The overlap between the fin whale feeding habitat and the microplastic hot spots is an important contribution for risk assessment of fin whale exposure to microplastics.

Highlights

In the Mediterranean Sea, marine litter has recently been confirmed as a critical issue (Eriksen et al, 2014; Cózar et al, 2015; UNEP/MAP, 2015; Suaria et al, 2016)
We present the results of the Plastic Pelagos survey aimed to investigate, using a multi-layer multidisciplinary approach, whether the fin whale feeding grounds and the areas of high floating plastic debris concentration can overlap and create critical conditions for fin whales exposed to plastic in the Pelagos Sanctuary
During the Plastic Pelagos survey, floating marine litter sampling and cetacean survey were conducted to verify the possible overlap between the marine litter accumulation areas and preferred fin whale feeding ground identified by regional hydrodynamic circulation and fin whale potential habitat models, in the Pelagos Sanctuary

Summary

Introduction

In the Mediterranean Sea, marine litter has recently been confirmed as a critical issue (Eriksen et al, 2014; Cózar et al, 2015; UNEP/MAP, 2015; Suaria et al, 2016). The same authors investigated the interaction between free-ranging fin whales and microplastics by comparing populations living in two semi-enclosed basins, the Mediterranean Sea and the Gulf of California (Mexico) (Fossi et al, 2016) In these studies, high concentrations of microplastics and plastic additives (phthalates) were detected in neustonic samples collected in the Pelagos Sanctuary for Mediterranean Marine Mammals (hereafter Pelagos Sanctuary). Pelagos Sanctuary is the only pelagic Marine Protected Area in the Mediterranean Sea, designated as one of the Specially Protected Areas of Mediterranean Importance (SPAMI) This marine area, located in the north-western Mediterranean Sea, is characterized by high offshore productive frontal features that attract a variety of large marine vertebrates including eight cetacean species (Coll et al, 2012). This exceptional biodiversity coexists with high human pressure (Fossi et al, 2013; Pinzone et al, 2015), including plastic pollution (Collignon et al, 2012; Fossi et al, 2012; Cózar et al, 2015)

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