Seto Inland Sea Regional Research Center, Kagawa University, Saiwai, Takamatsu, Kagawa 760-0016, Japan; Clean Ocean Ensemble, Sakate, Shodoshima, Shozu, Kagawa 761-4425, Japan.
Faculty of Agriculture, Kagawa University, Ikenobe, Miki, Kagawa 761-0701, Japan.
Mar Pollut Bull. 2024 Sep;206:116691. doi: 10.1016/j.marpolbul.2024.116691. Epub 2024 Jul 14.
This study examines microplastic (MP, 1-5 mm) densities in convergence zones in a coastal sea, the Seto Inland Sea, comparing them to those of non-convergence zones and other areas. Notably, Seto convergence zones exhibit MP densities 40 to 300 times higher than non-convergence zones, with an extraordinary density of 3.7 ± 6.3 pieces m, similar to densities found in Tokyo Bay as known a MP hotspot. The predominant polymer found was expanded polystyrene, varying seasonally and peaking in summer. Juvenile fish associated with driftweed in these convergence zones face a risk of long-term MP exposure, potentially up to four months. This large number of MPs found in coastal convergence zones is similar to accumulation zones formed in the gyres of open oceans, with strong implications for detrimental effects on coastal marine life. However, these MPs are autochthonous, and may be manageable through local marine plastic waste management.
本研究考察了濑户内海沿海汇聚区的微塑料（MP，1-5 毫米）密度，并与非汇聚区和其他区域进行了比较。值得注意的是，汇聚区的 MP 密度比非汇聚区高 40 到 300 倍，达到了 3.7±6.3 个/米，与已知的微塑料热点——东京湾的密度相当。研究发现，膨胀聚苯乙烯是主要的聚合物，其浓度存在季节性变化，夏季达到峰值。在这些汇聚区中，随漂流海藻移动的幼鱼面临着长期暴露于微塑料的风险，最长可达四个月。在沿海汇聚区发现的大量微塑料与开阔海洋环流中形成的积聚区相似，这对沿海海洋生物可能产生有害影响。然而，这些微塑料是本地产生的，通过当地的海洋塑料废物管理可能可以控制。
