2016 SoE Marine Chapter - Pressures - Toxins, pesticides and herbicides

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 toxins, pesticides and herbicides". 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.----------------------------------------DESCRIPTION OF THE PRESSUREThe group typically regarded as pollutants encompasses a large array of compounds and is generally divided into chemical compounds and metals. Estimates of the number of chemicals produced anthropogenically range as high as 100,000, however assessments of the toxicity and bioaccumulative nature of these are limited. Most research has only included a few classes of compounds, notably the halogenated hydrocarbons, a limited number of metals and polyaromatic and non-aromatic hydrocarbons.Most pollutants identified in marine animals are incorporated into tissues via dietary intake with many accumulating through the food web. Consequently, animals feeding at high trophic levels tend to have higher tissue concentrations than those feeding at lower trophic levels. Various pollutants have been reported to be associated with deleterious effects on the immune, endocrine and nervous systems of marine animals, resulting in disruption to growth, development, sexual differentiation and resistance to disease. However, direct associations between contaminants and these effects are few, and most studies lack substantive evidence of sublethal effects due to numerous confounding factors, both physiological and environmental in nature. This therefore limits quantification of the direct and indirect pressures pollutants may be exerting on the marine environment.DATA STREAM(S) USED IN EXPERT ASSESSMENTPublished papers and reports. Assessment has been conducted by literature review.----------------------------------------2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]• 2016 •Assessment grade: Low impactAssessment trend: UnclearConfidence grade: Limited evidence or limited consensusConfidence trend: Evidence and consensus too low to make an assessmentComparability: Grade and trend are somewhat comparable to the 2011 assessment• 2011 •Assessment grade: Very goodAssessment trend: StableConfidence grade: Limited evidence or limited consensusConfidence trend: Limited evidence or limited consensus----------------------------------------CHANGES SINCE 2011 SOE ASSESSMENTToxins, pesticides, herbicides was assessed under state and trends of physical and chemical processes rather than pressures.2016年《环境状况（State of the Environment, SoE）》报告海洋章节整合了基于多组海洋数据流构建的多套专家模板。本元数据记录针对《毒素、农药与除草剂相关的海洋环境压力》专家评估（Expert Assessment）进行说明。本记录附件包含完整的专家评估内容，含配图与附表（如已提供）。若可获取，本评估所依托的数据流（Data Stream）可通过本记录的「在线资源」板块查阅。 ---------------------------------------- 压力源说明 通常被归类为污染物的物质涵盖庞杂的化合物品类，大体可分为化学复合物与金属两大类。据统计，全球人为源化学品的总产量已逾10万种，但针对这些化学品的毒性与生物富集特性的系统性评估仍较为匮乏。现有多数研究仅覆盖少量化合物类别，典型包括卤代烃、有限种类的金属，以及多环芳烃与非芳烃烃类物质。 海洋生物体内检出的多数污染物均通过摄食途径进入机体组织，其中大量污染物可通过食物网发生富集。因此，处于较高营养级的海洋生物，其体内污染物的组织浓度往往高于营养级较低的物种。已有研究显示，多种污染物可对海洋生物的免疫、内分泌与神经系统造成不良影响，进而干扰其生长、发育、性别分化及疾病抵抗能力。但污染物与上述不良效应之间的直接关联证据稀缺，且由于生理与环境层面存在诸多混杂因素，多数研究难以提供亚致死效应的实质性佐证。这一局限使得难以量化污染物对海洋环境施加的直接与间接压力。 ---------------------------------------- 专家评估所用数据流（Data Stream） 已发表论文与报告。本评估通过文献综述方式完成。 ---------------------------------------- 2016年《环境状况》评估摘要【完整细节请参阅附件中的专家评估报告】 • 2016年： 评估等级：低影响 评估趋势：尚不明确 置信等级：证据有限或共识不足 置信趋势：证据与共识均不足，无法开展评估 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：良好 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 ---------------------------------------- 2011年《环境状况》评估以来的变更 此前，毒素、农药与除草剂的评估被归入物理与化学过程的状况及趋势范畴，而非压力源类别。