Evidence of microplastics in samples of zooplankton from Portuguese coastal waters.

Records of high concentrations of plastic and microplastic marine debris floating in the ocean have led to investigate the presence of microplastics in samples of zooplankton from Portuguese coastal waters. Zooplankton samples collected at four offshore sites, in surveys conducted between 2002 and 2008, with three different sampling methods, were used in this preliminary study. A total of 152 samples were processed and microplastics were identified in 93 of them, corresponding to 61% of the total. Costa Vicentina, followed by Lisboa, were the regions with higher microplastic concentrations (0.036 and 0.033 no. m⁻³) and abundances (0.07 and 0.06 cm³ m⁻³), respectively. Microplastic: zooplankton ratios were also higher in these two regions, which is probably related to the proximity of densely populated areas and inputs from the Tejo and Sado river estuaries. Microplastics polymers were identified using Micro Fourier Transformed Infrared Spectroscopy (μ-FTIR), as polyethylene (PE), polypropylene (PP) and polyacrylates (PA). The present work is the first report on the composition of microplastic particles collected with plankton nets in Portuguese coastal waters. Plankton surveys from regular monitoring campaigns conducted worldwide may be used to monitor plastic particles in the oceans and constitute an important and low cost tool to address marine litter within the scope of the Marine Strategy Framework Directive (2008/56/EC).

Frias JP ，Otero V ，Sobral P 《-》

Microplastics in coastal sediments from Southern Portuguese shelf waters.

Microplastics are well-documented pollutants in the marine environment that result from fragmentation of larger plastic items. Due to their long chemical chains, they can remain in the environment for long periods of time. It is estimated that the vast majority (80%) of marine litter derives from land sources and that 70% will sink and remain at the bottom of the ocean. Microplastics that result from fragmentation of larger pieces of plastic are common to be found in beaches and in the water surface. The most common microplastics are pellets, fragments and fibres. This work provides original data of the presence of microplastics in coastal sediments from Southern Portuguese shelf waters, reporting on microplastic concentration and polymer types. Microplastic particles were found in nearly 56% of sediment samples, accounting a total of 31 particles in 27 samples. The vast majority were microfibers (25), identified as rayon fibres, and fragments (6) identified as polypropylene, through infrared spectroscopy (μ-FTIR). The concentration and polymer type data is consistent with other relevant studies and reports worldwide.

Frias JP ，Gago J ，Otero V ，Sobral P ... -  《-》

Abundant plankton-sized microplastic particles in shelf waters of the northern Gulf of Mexico.

Accumulation of marine debris is a global problem that affects the oceans on multiple scales. The majority of floating marine debris is composed of microplastics: plastic particles up to 5 mm in diameter. With similar sizes and appearances to natural food items, these small fragments pose potential risks to many marine organisms including zooplankton and zooplanktivores. Semi-enclosed seas are reported to have high concentrations of microplastics, however, the distribution and concentration of microplastics in one such system, the Gulf of Mexico, remains unknown. Our study documented and characterized microplastics in continental shelf waters off the Louisiana coast in the northern Gulf of Mexico, using bongo nets, neuston nets, and Niskin bottles. Additionally, we compared the size distributions of microplastics and zooplankton collected using the nets. Plastics were manually sorted from the samples, documented, and measured using digital microscopy. Confirmation of putative plastics was carried out by hydrofluoric acid digestion and a subsample was analyzed using FTIR microscopy. Estimated concentrations of microplastics collected on the inner continental shelf during this study are among the highest reported globally. Total microplastic concentrations ranged from 4.8 to 8.2 particles m-3 and 5.0-18.4 particles m-3 for the bongo and neuston samples, respectively. Niskin bottles collected smaller plastic particles than the nets and indicated total microplastic concentrations (primarily fibers) from 6.0E4 - 15.7E4 particles m-3. Microplastic concentrations were greater than the abundances of all but four of the five most abundant taxa from bongo nets and were not statistically different from the abundances of any of the most numerous taxa from neuston nets. Sizes of microplastics and zooplankton partially or completely overlapped, suggesting the potential for confusion with natural prey.

Di Mauro R ，Kupchik MJ ，Benfield MC 《-》

Microplastics in Singapore's coastal mangrove ecosystems.

The prevalence of microplastics was studied in seven intertidal mangroves habitats of Singapore. Microplastics were extracted from mangrove sediments via a floatation method, and then counted and categorized according to particle shape and size. Representative microplastics from Berlayar Creek, Sungei Buloh, Pasir Ris and Lim Chu Kang were isolated for polymer identification using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. Microplastics were identified in all seven habitats, with the highest concentration found in sediments at Lim Chu Kang in the northwest of Singapore. The majority of microplastics were fibrous and smaller than 20 μm. A total of four polymer types were identified, including polyethylene, polypropylene, nylon and polyvinyl chloride. The relationship between abundance of microplastics and sediment grain size was also investigated, but no relationship was apparent. The presence of microplastics is likely due to the degradation of marine plastic debris accumulating in the mangroves.

Nor NH ，Obbard JP 《-》

First evaluation of neustonic microplastics in Black Sea waters.

The Black Sea has a high risk of plastic pollution given the high river discharge of several industrialized countries into this semi-enclosed sea. Here, for the first time, the occurrence and distribution of microplastics are reported for the Black Sea. Microplastics were assessed from zooplankton samples taken during two cruises along the south eastern coast of the Black Sea in the November of 2014 and February of 2015. In each cruise neuston samples were collected at 12 stations using a WP2 net with 200 μm mesh. Microplastics (0.2-5 mm) were found in 92% of the samples. The primary shapes were fibres (49.4%) followed by plastic films (30.6%) and fragments (20%), and no micro beads were found. Average microplastic concentration in November (1.2 ± 1.1 × 10(3) par. m(-3)) was higher than in February (0.6 ± 0.55 × 10(3) par. m(-3)). Reduced concentrations in February were possibly caused by increased mixing. The highest concentrations of microplastics were observed in offshore stations during November sampling. The heterogeneous spatial distribution (0.2 × 10(3)-3.3 × 10(3) par. m(-3) for all samples) and accumulation in some stations could be associated to transport and retention mechanisms linked with wind and the dynamics of the rim current, as well by different sources of plastic. There were no statistically significant differences in MP concentration between sampling stations and sampling periods (t-test, p < 0.05).The relatively high microplastic concentrations suggest that Black Sea is a hotspot for microplastic pollution and there is an urgency to understand their origins, transportation and effects on marine life.

Aytan U ，Valente A ，Senturk Y ，Usta R ，Esensoy Sahin FB ，Mazlum RE ，Agirbas E ... -  《-》