Geography and Spatial Sciences, School of Land and Food, University of Tasmania, Hobart, TAS, 7001, Australia.
Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, Hobart, TAS 7000, Australia.
Sci Rep. 2017 Mar 10;7:44479. doi: 10.1038/srep44479.
Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean.
海洋垃圾是一个迅速发展的全球性问题，对经济、生态和美学都有影响。虽然现在有很多研究都在探讨这个问题，但城市化因素如当地人口密度、雨水渠和道路对沿海垃圾分布的影响仍未得到充分理解。为了解决这一知识空白，我们在澳大利亚塔斯马尼亚州的两个河口和开阔海岸的 67 个地点进行了 224 次横断面调查，开展了标准化调查。我们探讨了三个关于垃圾来源假说的相对支持程度；海滩游客的直接沉积、通过雨水渠和沿海径流从周边地区的输送，以及从海洋系统的陆上输送。我们发现所有三种机制都得到了强有力的支持，但从海洋库的陆上输送是最重要的机制。总的来说，这三个模型共同解释了我们观测结果的 45.8%。我们的研究结果还表明，进入海洋环境的大部分垃圾都是在当地沉积的，这可能就是海洋中所有丢失的塑料都在哪里的答案。此外，当地干预措施可能是减少陆地向海洋输入的最有效方法。
