In situ ingestion of microfibres by meiofauna from sandy beaches

Environmental Pollution xxx (2016) 1e7

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Short communication

In situ ingestion of microfibres by meiofauna from sandy beaches* ~o a, *, Maikon Di Domenico b, d, g, A. Cecilia Z. Amaral c, Felipe Gusma Alejandro Martínez d, e, Brett C. Gonzalez d, Katrine Worsaae d, Juliana A. Ivar do Sul f, Paulo da Cunha Lana g ~o Paulo (UNIFESP), 11030-400 Santos, SP, Brazil Department of Marine Sciences, Federal University of Sa ~o Jos University of Campinas (UNICAMP), Biological Institute (IB), Zoological Museum “Prof. Dr. Ada e Cardoso”, Brazil c Departamento de Biologia Animal (Zoologia), Instituto de Biologia, Universidade Estadual de Campinas, R. Monteiro Lobato, 255, 13083-862 Campinas, SP, Brazil d Marine Biological Section, University of Copenhagen, Universitetsparken 4, 2100, Copenhagen, Denmark e Italian National Research Council, Institute of Ecosystems Study, Largo, Tonolli 50, 28922, Verbania, Italy f Institute of Oceanography, Federal University of Rio Grande, Av. Italia, km 8 - Carreiros Rio Grande - RS, 96201-900, Brazil g , Brazil Benthos Lab, Centre for Marine Studies, Universidade Federal do Parana a

b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 8 April 2016 Received in revised form 7 June 2016 Accepted 7 June 2016 Available online xxx

Microfibres are widespread contaminants in marine environments across the globe. Detecting in situ ingestion of microfibres by small marine organisms is necessary to understand their potential accumulation in marine food webs and their role in marine pollution. We have examined the gut contents of meiofauna from six sandy beaches in the Atlantic Ocean and the Mediterranean. Out of twenty taxonomic groups, three species of the common sandy beach annelid Saccocirrus. Displayed in situ ingestion of microfibres in all sites. Laboratory observations showed that species of Saccocirrus are able to egest microfibres with no obvious physical injury. We suggest that their non-selective microphagous suspension-feeding behaviour makes Saccocirrus more prone to ingest microfibres. Although microfibres are rapidly egested with no apparent harm, there is still the potential for trophic transfer into marine food webs through predation of Saccocirrus. © 2016 Elsevier Ltd. All rights reserved.

Keywords: Microplastics Microfibres Saccocirrus Annelida Interstitial

1. Introduction Marine debris, especially plastics, are currently considered a major environmental threat since they are easily transported and accumulated in all marine environments (Barnes et al., 2009; Moore, 2008; Thompson et al., 2009). The impacts of large debris on the marine environment have received much attention, mainly because they are often ingested by seabirds, sea turtles, fish, and marine mammals (Gall and Thompson, 2015; Moore, 2008). Further attention has recently been given to the occurrence and effects of smaller plastic particles, known as microplastics, in marine waters. These microplastics are plastic particles smaller than 5 mm that

* This paper has been recommended for acceptance by Eddy Y. Zeng. * Corresponding author. E-mail addresses: [email protected] (F. Gusm~ ao), [email protected] (M.D. Domenico), [email protected] (A.C.Z. Amaral), [email protected] (A. Martínez), [email protected] (B.C. Gonzalez), [email protected] (K. Worsaae), [email protected] (J.A. Ivar do Sul), [email protected] (P. Cunha Lana).

enter the aquatic environment by the breakdown of larger plastic items or direct release from textile fibres, abrasives, and cleaning products (Arthur et al., 2009; Browne et al., 2011, 2007; Thompson et al., 2009). They may accumulate higher concentrations of persistent organic pollutants (POPs) than macroplastics (Teuten et al., 2007), and are much more difficult to be detected, monitored, and effectively removed from the environment (McElwee and Osborn, 2011). The steep increase in the number of studies on microplastics pollution in recent years prompted the development of more efficient protocols for the assessment of these pollutants in the aquatic environment (e.g. Hidalgo-Ruz et al., 2012; Nuelle et al., 2014; Van Cauwenberghe et al., 2015; Woodall et al., 2015). These techniques have allowed the observation of a variety of forms and types of microdebris in the marine environment. Microfibres are among the most common microdebris in marine samples worldwide (e.g. Habib et al., 1998; Imhof et al., 2013; Mathalon and Hill, 2014; Nuelle et al., 2014). While plastic polymers are a common component of microfibres collected in situ, recent studies have shown that

http://dx.doi.org/10.1016/j.envpol.2016.06.015 0269-7491/© 2016 Elsevier Ltd. All rights reserved.

~o, F., et al., In situ ingestion of microfibres by meiofauna from sandy beaches, Environmental Pollution Please cite this article in press as: Gusma (2016), http://dx.doi.org/10.1016/j.envpol.2016.06.015

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~o et al. / Environmental Pollution xxx (2016) 1e7 F. Gusma

Fig. 1. Map of sampling locations.

the composition of these microfibres is more diverse (e.g. Lusher et al., 2013), suggesting that some reports of microfibres as microplastics in the literature may be incorrect (Remy et al., 2015). Fibres can be categorized as natural or man-made in origin. Natural fibres are those produced from natural sources, such as wool and cotton (ISO 6938:2012, 2012). Man-made fibres are those produced by the transformation of natural fibres such as cellulose, and those produced by synthetic processes such as thermoplastic fibres, nylon, polyester and acrylic (ISO, 2076:2013, 2013). The pathway of fibres entering the aquatic environment is not yet well understood, but there is evidence suggesting that the manufacture and washing of textiles (Browne et al., 2011) and wastewaters are major pathways of fibres to the environment (Talvitie et al., 2015; Zubris and Richards, 2005). There is also increasing evidence of fishing gear as a potential source of microfibres to the aquatic environment, such as coloured nylon fibres ingested by fish (Possatto et al., 2011) and found on lake shores (Imhof et al., 2013). Microfibres are widespread in the marine environment, being commonly observed in coastal and oceanic water samples (Desforges et al., 2014) and deep sea sediments (Woodall et al., 2015). When in suspension in the water column, microfibres are often more abundant close to the coast than in offshore environments (Desforges et al., 2014). Consequently, microfibres are a contaminant in beach sediment, often reported concurrently with various types of microplastics (Liebezeit and Dubaish, 2012). Maximum densities of microfibres in beach sediments are often lower than that reported for various microplastics, but microfibres are more homogeneously distributed in the environment than other microplastics (Liebezeit and Dubaish, 2012). The size of microfibres found in beach sediments can vary widely, but most authors report diameters of about 1 mm (Frias et al., 2010) to 20 mm (Thompson et al., 2004) and microfibre lengths varying between

15 mm and 500 mm (Frias et al., 2010). The potentially harmful impact of microfibres in the environment is understudied, but considering that plastic is a major component of many microfibres found in situ (e.g. Lusher et al., 2013), it is likely that microfibres share similar environmental problems as microplastics. Some of the potentially harmful impacts include microfibre ingestion by marine animals (Browne et al., 2008) and subsequent transfer throughout marine food webs (e.g. € et al., 2014). Their potential to sorb Farrell and Nelson, 2013; Set€ ala chemical pollutants (Ladewig et al., 2015) raises further concern. In situ ingestion of microfibres is known for crabs (Watts et al., 2015), €mer et al., 2014), lobsters (Murray and Cowie, 2011), isopods (Ha amphipods (Ugolini et al., 2013), mussels (De Witte et al., 2014), fish (Davison and Asch, 2011; Lusher et al., 2013; Possatto et al., 2011) and birds (Zhao et al., 2016). Some reports of ingestion of microfibres suggest that these particles can even be a more problematic environmental issue than microplastics. For instance, microfibres were the main type of microdebris ingested by several pelagic and demersal fish from the English Channel (Lusher et al., 2013). In this study, we have systematically searched for microfibres in the gut content of twenty meiofaunal groups from six sandy beaches of the Atlantic and the Mediterranean and carried out lab observations on the feeding behaviour of the common annelid Saccocirrus, which was found to ingest microfibres at all studied sites. 2. Materials and methods 2.1. Study location Six sandy beaches were sampled from the Atlantic Ocean and Mediterranean Sea. From the West Atlantic, Estaleiro and Estaleirrio inho beaches were sampled in the South of Brazil (Balnea



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Table 1 Biodiversity and microfibres ingestion of benthic meiofauna in sandy beaches from Brazil, the Canary Islands, and Italy. Y indicates the taxa was observed with microfibres in its gut. N indicates the specific taxa was observed, but without microfibres in its gut. Species/Taxa

Saccocirrus pussicus Saccocirrus papillocercus Saccocirrus sp. 1 Claudrilus ovarium Claudrilus sp. 1 Meiodrilus gracilis Protodrilus albicans Protodrilus oculifer Lindrilus n. sp. Megadrilus schneideri Meiodrilus sp. 1 Nerilla mediterranea Hesionura laubieiri Hesionides sp. Hesionura sp. Syllidae Stygocapitella sp. Naididae Otoplanidae Ototyphlonemertes sp. Isopoda Harpacticoida Mystacocarida Gastrotricha Ostracoda Tardigrada Nematoda

Brazil

Canary islands

Estaleiro

Estaleirinho

Leme

Y

Y

Y

Italy

La Barranquilla

Los Abades

Y

Y

N

N

Cala Spalmadori Y

N

N

N N N N N

N N N N N N

N N

N N

N

N

N

N N N N N N

N N N N N

N N N

N N N

N N N N

Camboriú, in September 2010), and Leme beach from the Southeast (Rio de Janeiro, in August 2011) coast of Brazil. Eastern Atlantic samples were from Abades (December 2010) and Barranquilla (April 2014) in Tenerife in the Canary Islands, and Cala Spalmadori (September 2014) in Sardinia (Italy) in the Mediterranean Sea (Fig. 1). Sampling locations were all exposed reflective beaches with high slopes displaying very coarse to coarse grain sizes, embayment between headlands, the absence of redox layers, and high hydraulic flux in the swash zone. Estaleiro and Estaleirinho beaches in Brazil are common tourist destinations and used daily by tourists and recreational fishermen. In contrast, Abades and Barranquilla beaches in the Canary Islands are not common tourist destinations, but are located nearby wharfs that are used by local fishermen to repair their gear. Cala Spalmadori is an isolated beach located in the Asinara National Park protected area, and although rarely used by people, it accumulates larger floating debris transported by currents.

2.2. Sampling technique and preparation Sediment samples were collected manually from the swash and surf zone and by divers in the subtidal zone. Sampling effort was similar in all beaches, with five sampling sites per beach resulting in approximately 80 L of sand per beach. This sampling design has been successful in maximizing individual capture of beach meiofauna in taxonomic studies (e.g. Di Domenico et al., 2014b, 2014c). Upon collection, samples were immediately transported to the laboratory for further processing. Subsamples were taken and sorted, from which animals were removed for behavioural observation. Animals were extracted from the sediment by decantation after anesthetizing the sample with an isotonic MgCl2 solution (Higgins and Thiel, 1988) and gently revitalized in a Petri dish with seawater for further examination.

N

N

N N N

N N

N

N

N

N

N

N

N

N

N

2.3. Behavioural observations Behaviour observations of meiofaunal Saccocirrus spp. annelids were carried out on samples from Estaleiro and Estaleirinho beaches. Live animals were video recorded using a Canon PowerShot S45 video camera mounted on an Olympus SZH-ILLD stereomicroscope. Microfibres were clearly visible within the gut of live animals. In order to determine the ability of the specimens to egest microfibres, we maintained the animals in Petri dishes with clean seawater and without food for up to 24 h. 2.4. Sample preservation and analysis Species of Saccocirrus and associated meiofauna were identified alive and fixed in 2% glutaraldehyde in cacodylate buffer (24 h, subsequently transferred to 0.1 M cacodylate buffer). Following fixation, specimens of interest were mounted in glycerol on glass slides for morphological assessment and species identification usmoff et al., 2004) was used to ing a dissecting scope. ImageJ (Abra measure the body length and the dimensions of the gut contents from the photographs of each individual containing microfibres within the gut. We tried to identify the material of which the microfibres were made by means of FTIR analysis with an ATR unit, but the analysis was unsuccessful due to the small size of the particles. However, we verified the anthropogenic nature of the n (2007) and microfibres by applying the criteria described in Nore Hidalgo-Ruz et al. (2012). 3. Results and discussion 3.1. Diversity of local meiofaunal assemblages A total of 27 species/taxa were observed in all studied locations. The main lineages found inhabiting the intertidal and subtidal


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Fig. 2. Light micrographs showing the ingestion of microfibres by Saccocirridae annelids. A-B) Microfibre in the gut of Saccocirrus pussicus; C) Alimentary canal containing detritus and sand grains; D) Sharp point of blue microfibre piercing the mouth of Saccocirrus sp. 1 from Abades; E) Microfibres recovered from the sampled sediment; F) Microfibre in the gut of Saccocirrus sp. 1 from Abades beach. Legend: py ¼ pygidium, pr ¼ prostomium; pa ¼ palps; mf ¼ microfibre; gu ¼ gut; sg ¼ sand grain. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

zones of all studied sandy beaches were Annelida, Platyhelminthes, Copepoda and Nematoda (Table 1). Analysis of similarity (ANOSIM) suggest the meiofaunal assemblages from the three studied locations are significantly different (Raup-Crick similarity on presenceabsence data, R ¼ 1, p < 0.05). Amongst the Annelids, species of Saccocirrus and Protodrilidae were recorded at all studied sites. Taxa richness was highest in Brazilian and Italian beaches, varying from 9 to 14, and lowest at the Canary Island beaches, with 6 and 9 recorded taxa.

3.2. Evidence of in situ ingestion of microfibres from field samples Despite the various taxa in our samples, we only observed microfibres in the guts of the saccocirrid annelids Saccocirrus pussicus from Brazil, Saccocirrus papillocercus from Italy, and Saccocirrus sp. 1 from the Canary Islands (Di Domenico et al., 2014c). Individuals of Saccocirrus with microfibres inside their gut were observed in all beaches (Table 1). All ingested microfibres were monofilament strands, heavily coloured (blue or red), with a rigid



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Fig. 3. Light micrographs of the ingestion of microfibres by Saccocirrus sp. 1 from La Barranquilla, Canary Islands. A) Specimen 1, blue microfibre tangled in the gut; B) and D) Specimen 2, blue and red microfibres tangled in the gut; C) Specimen 3, blue and red microfibre curled in the gut. Legend: py ¼ pygidium, pr ¼ prostomium; pa ¼ palps; mf ¼ microfibre; gu ¼ gut; sg ¼ sand grain. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

conformation, not friable when handled, and often sharp-edged. Microfibres had a cylindrical shape varying in length from 2 to 4 mm and ranging between 25 and 100 mm in diameter (Figs. 2 and 3). The origin of these microfibres is unknown, but their characteristics are similar to those described for synthetic microfibres often observed in situ (Remy et al., 2015). Their appearance and size suggests they are likely fragments of fishing lines and nets or clothing/industrial material made of plastic polymer. One microfibre was found per animal, often twisted inside the gut, either packed resembling a normal food bolus (Fig. 2 AeB) or loose and occupying most of the gut (Fig. 3). The gut and body walls of most of the animals that ingested microfibres showed no obvious damage. Only once in an already fixed animal the sharp edge of an ingested microfibre was seen piercing the mouth (Fig. 2D). Microfibres similar to those inside the guts of Saccocirrus species were present throughout the sediment at the collection times (Fig. 2E). 3.3. Behaviour of Saccocirrus in laboratory following the in situ ingestion of microfibres Saccocirrus individuals keep their living position in a semisedentary way most of the time, adhered to the substrate by adhesive glands along the pygidial ridges. They occasionally swim by undulating body movements, mostly after being disturbed. They spend most of their time actively capturing and ingesting food particles, mainly particulate matter and small sand grains. Active

suspension feeding was observed in both swimming and adhered individuals. Suspension feeding in adhered individuals was characterized by constant waving of the palps around the mouth, collecting food particles from the water column and transporting them towards the mouth by coiling the entire palp (Di Domenico et al., 2014b). Guts containing microfibres were devoid of other material such as sand grains and detritus (Fig. 2C). When packed like a normal food bolus, microfibres occupied a few body segments (about 4 or 5 segments) in length (Fig. 2A and B). Microfibres inside the gut were relatively rigid, and apparently limited segment mobility (see supplementary videos). All observed microfibres in the gut content were evacuated during the laboratory observation period (