2016 SoE Marine Chapter - Pressures - Dumped wastes

The Marine chapter of the 2016 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "Pressures on the marine environment associated with dumped wastes". The full Expert Assessment, including figures and tables (where provided), is attached to this record. Where available, the Data Stream(s) used to generate this Expert Assessment are accessible through the "On-line Resources" section of this record.

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DESCRIPTION OF THE PRESSURE
Dredging associated with the development or maintenance of port facilities around the coast of Australia is a necessary and unavoidable activity, vital to the continuity of the Australian economy. Disposal of dredged material is mostly commonly by placement on the sea floor in specially designated areas. By volume this is by far the largest pressure on the marine environment due to “dumped waste” and over the period from 2011 to 2016 totalled in the region of 90 million cubic meters of sediment (Ports Australia 2014, 2015). The areas selected as disposal sites and the nature of disposed dredged material at sea are highly regulated to minimise the risk of marine organisms being exposed to toxic materials and that the sites chosen are the most likely to be minimally affected by the application of additional sediment (Ports Australia 2014). Pressures arising from this practice include direct burial of biota as well as less direct impacts arising from resuspension of sediments placed on the sea floor. While the footprint of disposal sites is relatively small on the scale of Australia’s continental shelf, the area affected by remobilised material is potentially larger and less well known (McCook et al 2015).

The amount of dredged material disposed of at sea in the 5 year period up to 2016 has increased markedly over that reported up to 2011 (Fig. 1). This is mainly due to two large port developments in north-western Australia’s Pilbara region (Gorgon and Wheatstone). Generally there appears to have been a strong upward trend in volumes in the Pilbara over the past decade and two new project approvals have been granted for a further 34 million cubic meters at Anketell Port and 42 million cubic meters at Port Hedland of dredging and disposal in the region. Given the decline in resource development experienced since 2014, this trend may abate in the short term.

DATA STREAM(S) USED IN EXPERT ASSESSMENT
Data used in assessment cover the entire continental coastal zone of Australia, and include all major ports. See "On-line resources" section of this record for links to specific data products.

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2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]

• 2016 •
Assessment grade: Good
Assessment trend: Stable
Confidence grade: Adequate high quality evidence and high level of consensus
Confidence trend: Adequate high quality evidence and high level of consensus
Comparability: Grade and trends are somewhat comparable to the 2011 assessment
• 2011 •
Assessment grade: Very good
Assessment trend: Stable
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus

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CHANGES SINCE 2011 SOE ASSESSMENT
At sea dumping was not included in the 2011 SOE assessment as a separate section, where it is barely mentioned.

2016年环境状况（State of the Environment, SoE）报告海洋章节整合了多套基于海洋数据流构建的专家模板。本元数据记录对应专家评估报告《海洋环境受倾倒废弃物影响的压力》。本记录附件包含完整的专家评估报告，含相关图表（如已提供）。若有可用数据，生成该专家评估所用的数据流可通过本记录的"在线资源"板块获取。

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压力源说明
澳大利亚沿海港口设施建设与维护相关的疏浚作业，是保障澳大利亚经济持续运转的必要且不可替代的活动。疏浚物的主流处置方式为将其倾倒至专门划定的海底区域。按体积计算，这类"倾倒废弃物"是当前对海洋环境影响最显著的压力源，2011至2016年间总疏浚沉积物量约达9000万立方米（澳大利亚港口协会[Ports Australia] 2014、2015）。处置场地的选址及海上疏浚物的处置规范均受到严格监管，旨在最大程度降低海洋生物接触有毒物质的风险，并确保所选场地受额外沉积物扰动的影响程度最低（澳大利亚港口协会 2014）。该处置方式带来的环境压力包括生物群落直接被掩埋，以及海底疏浚沉积物再悬浮引发的间接影响。尽管就澳大利亚大陆架整体规模而言，处置场地的占地面积相对较小，但再悬浮沉积物影响的区域可能更广，且相关监测研究尚不充分（McCook等人2015）。

截至2016年的五年间，海上倾倒疏浚物的总量较2011年的统计数据出现显著增长（图1）。这一增长主要源于澳大利亚西北部皮尔巴拉地区的两项大型港口开发项目（高更[Gorgon]与惠斯通[Wheatstone]）。近十年来，皮尔巴拉地区的疏浚物处置总量整体呈强劲上升趋势；目前已有两项新工程获批，将分别在安克特利尔港（Anketell Port）新增3400万立方米疏浚处置量，在黑德兰港（Port Hedland）新增4200万立方米疏浚处置量。鉴于2014年以来当地资源开发活动有所下滑，该增长趋势短期内或有所放缓。

专家评估所用数据流
本次评估所用数据覆盖澳大利亚全部大陆沿海区域，涵盖所有主要港口。具体数据产品的链接可参阅本记录的"在线资源"板块。

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2016年环境状况评估总结【完整详情请参阅附件中的专家评估报告】
• 2016年 •
评估等级：良好
评估趋势：稳定
置信等级：具备充足高质量证据与高度共识
置信趋势：具备充足高质量证据与高度共识
可比性：本次评估等级与趋势与2011年评估结果具备一定可比性
• 2011年 •
评估等级：优秀
评估趋势：稳定
置信等级：证据有限或共识不足
置信趋势：证据有限或共识不足

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2011年环境状况评估以来的变化
2011年环境状况评估未将海上倾倒列为独立章节，仅略有提及。