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8 M. Angiolillo et al. / Marine Pollution Bulletin xxx (2015) xxx–xxx

Table 3 contrary, the use of alternative investigative methods (e.g. sub-
Results of mixed logistic models for presence/absence of damages in each sampling mersibles, ROVs), allow researchers to assess the abundance and
unit. Results are grouped by damage (outcomes) and the relationship with region of type of general debris found on structurally complex rocky banks
sampling is investigated. For each outcome, regions with larger Odd Ratio (OR) are at (Chiappone et al., 2005; Keller et al., 2010; Watters et al., 2010;
higher risk of showing the specific kind of damage with respect to regions with a Mordecai et al., 2011), that are particularly subjected and impacted
smaller OR. by recreational and professional fishing pressure (Bo et al., 2013).

Damage Region OR C.I. 95% 0.112 P value In this study, in fact, the occurrence of debris is mainly caused
Abrasion 0.600 by fishing gears, particularly lost lines, which represent about a
Campania 0.053 0.025 2.540 <0.001 half of all debris found in Campania and Sardinia. While in Sicily,
Covering Sardinia 0.228 0.087 0.003 this value reached about 80%. The explored off-shore deep rocky
Sicily 0.845 0.281 0.058 0.765 banks in Sicily host numerous commercially relevant fishing
Hanging 0.726 stocks, that attract local recreational and professional fishing boats
Campania 0.029 0.015 1.740 <0.001 (Bo et al., 2013), likely responsible for the great abundance of lines
Lying Sardinia 0.289 0.115 0.008 found in this area. However, this pattern of debris composition is
Sicily 0.576 0.191 0.076 0.328 comparable with ones recorded by other authors. For example,
0.318 Chiappone et al. (2002, 2004, 2005) studied shallow areas of Flor-
Campania 0.038 0.019 1.782 <0.001 ida, where fishing gears, mainly lines, contributed to up to 90% of
Sardinia 0.111 0.039 <0.001 the total quantified litter. In deep areas, similar results were
Sicily 0.613 0.211 0.070 0.368 obtained by Watters et al. (2010) off the coasts of California, and
0.750 by Bo et al. (2014) in five Tyrrhenian banks. The above findings
Campania 0.035 0.017 4.039 <0.001 highlight that fishing litter may be predominant in areas character-
Sardinia 0.299 0.119 0.010 ized by intense fishing activities, such as the western Mediterra-
Sicily 1.510 0.565 0.412 nean Sea (Mordecai et al., 2011). Moreover, it can take up to six
hundred years to decompose a nylon line (Bianchi et al., 2004).
Table 4 Consequently, dangerous synthetic debris appears to be fishing
Percent frequency (%) of taxa impacted by debris (T) and taxa occurrence (frequency gears, which can cause entanglement and also break down over
of taxa respect to the total regional frames, F) in each investigated region. time into dangerous fragments that can be ingested by organisms
(Laist, 1987). Therefore, the wide distribution of this debris repre-
Taxa Campania (%) Sardinia (%) Sicily (%) sents an important source of perturbation on the Mediterranean
TI F TI F TI F sensitive ecosystem.
PORIFERA
Aplysina cavernicola 4.7 6 – – –– All the explored sites hosted coral and sponge aggregations that
Poecillastra compressa – 14.5 7.9 –– have now been internationally identified as special ecological fea-
tures that require protection under the Convention of Biological
ANTHOZOA – 56 – 0.6 3.6 0.8 Diversity (Aguiliar and Marín, 2013). Fishing litter in the studied
Chironephthya mediterranea – 64 – 1.3 – 5.2 areas had a major impact on these benthic communities, mainly
Acanthogorgia hirsuta 22.7 0.4 47.3 38 1.8 5.6 on the arborescent large coral colonies, that are easily snagged
Corallium rubrum 41.5 – 5.4 16 3.6 11 by derelict gears. More than half of the recorded debris seriously
Eunicella cavolinii – – – 1.9 1.8 0.1 impacted the benthic organisms by covering and abrading their tis-
Eunicella verrucosa – 24 5.5 4 – 0.4 sues (Fig. 4). These results are consistent with Bo et al. (2013, 2014)
Viminella flagellum – 4 3.6 1.8 – 2 findings, indicating that lost lines affect 30% of arborescent corals
Bebryce mollis 30.2 0.3 7.3 1.9 12.5 11 found in the deep Tyrrhenian rocky banks. Chiappone et al.
Paramuricea clavata – – – 0.8 7.1 14 (2005) have found that lost lines were responsible for damaging
Paramuricea macrospina – – 9.1 12 14.3 7.5 84% of all sponges and benthic cnidarians in the Florida Keys
Callogorgia verticillata – 0.1 1.8 1.5 – – National Marine Sanctuary.
Antipathes dichotoma – 0.3 1.8 6.1 – –
Leiopathes glaberrima – 0.4 – 3.7 51.8 13 Yoshikawa and Asoh (2004) have demonstrated that older cau-
Antipathella subpinnata 0.9 0.1 – – 3.5 3 liflower coral colonies, with large surface areas have a greater risk
Ceriantharia – 1.8 2.6 – – of entanglement compared to smaller younger colonies. Some of
Dendrophyllia cornigera – 1.9 0.3 – – the most damaged specimens in this study were erect filter feeders
Savalia savaglia composed of tall and branched colonies (as the octocorals P. clavat-
a, E. cavolinii, C. verticillata, C. rubrum and the antipatharians A. sub-
However, the extensive spatial variation of waste may be related to pinnata, Antipathes dichotoma and Leiopathes glaberrima). Coral
hydrographical factors as well as to geomorphologic factors skeletal characteristics, such as stiffness and flexibility of a colony,
(Galgani et al., 2000; Mordecai et al., 2011), which are likely are known to play an important role in the resistance of friction,
responsible for the transportation and accumulation of marine which explains the different responses of protein-based gorgo-
debris at greater depths (Galgani et al., 1996). nians or chitinous-based antipatharians to mechanical impacts
(Bo et al., 2013). Due to their elastic skeletons, E. cavolinii gorgo-
On the basis of previous studies, plastic items are generally con-
sidered the most diffused marine debris (Galil et al., 1995; Galgani
et al., 1996, 2000; Law et al., 2010; Miyake et al., 2011). The data in
this study indicate that the evidence of these type of debris can be
biased on the kind of explored sea bottom and the employed meth-
ods (Watters et al., 2010) such as the selective exploration of bot-
toms exploited by trawling nets (Galgani et al., 1996). On the

Table 5
Percent frequency (%) of colonization degree on different debris types (lines, nets and other debris) and on all debris (tot) by macro-benthic invertebrates in each surveyed region.

Fishing gear Campania (%) Sardinia (%) Sicily (%)

Colonization Line Net Other Tot Line Net Other Tot Line Net Other Tot

None 9.5 0.0 35.0 9.7 33.3 3.8 46.7 27.4 34.6 0.0 50.0 30.7
Moderate 44.2 34.0 25.0 38.8 42.6 30.8 46.7 40.0 44.4 50.0 50.0 45.5
Heavy 46.3 66.0 40.0 51.5 24.1 65.4 6.6 32.6 21.0 50.0 0.0 23.8

Please cite this article in press as: Angiolillo, M., et al. Distribution and assessment of marine debris in the deep Tyrrhenian Sea (NW Mediterranean Sea,
Italy). Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/j.marpolbul.2014.12.044