2016 SoE Marine Chapter - State and Trends - Marine connectivity based on physical processes

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 "The state and trends of physical, biogeochemical and biological processes – Marine connectivity based on physical processes". 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 ECOLOGICAL PROCESS FOR EXPERT ASSESSMENT
Marine biological connectivity around Australia is driven by physical processes such as winds, waves, tides and currents, that operate across a wide range of time and space scales. These water movements carry and disperse dissolved substances (nutrients and chemical pollutants) and particulates (sediments, marine debris and planktonic organisms) that are critical to the functioning of marine ecosystems. High connectivity can have positive or negative influences on ecosystem components depending on the circumstances, as can low connectivity (i.e. high retention). For example, transport of eggs and larvae from spawning grounds to nursery areas may be critical to successful breeding, but may also contribute to the spread of harmful species.

Over Australia’s mid- and inner- continental shelves circulation and connectivity patterns tend to be dominated by wind and tidal influences, while the offshore environment is strongly influenced by major currents systems including the poleward flowing Leeuwin Current (LC) in the west and its extension along the southern Australian coast to Tasmania, and the East Australia Current (EAC) in the east. The strength of these currents varies with decadal forcing cycles, such as ENSO, SAM, and IOD, and in some locations there is also evidence of long-term connectivity change consistent with climate change. For example, increased southward flow of the EAC (Ridgway 2007) has been associated with major southward range extensions for almost 100 species (Frusher et al 2014; Sunday et al 2015). This represents a major increase in connectivity between northern and southern biological populations along the eastern seaboard. In contrast, this southern extension may have reduced connectivity in the south-to-north direction.

DATA STREAM(S) USED IN EXPERT ASSESSMENT
Published papers. CSIRO creates and maintains models used to study dispersal (Bluelink – BRAN product). IMOS holds data on ocean current strength, individual researchers hold data on species of interest. Report Cards have started to explicitly include connectivity as an indicator - http://ghhp.org.au/report-cards/2015/environmental.

----------------------------------------

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

• 2016 •
Assessment grade: Poor
Assessment trend: Deteriorating
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus
Comparability: Grade and trend are not directly comparable to the 2011 assessment
• 2011 • Connectivity – spatial/physical disjunctions
Assessment grade: Very good
Assessment trend: Stable
Confidence grade & trend: Limited evidence or limited consensus
• 2011 • Connectivity – biological, migration, flyways
Assessment grade: Good
Assessment trend: Deteriorating
Confidence grade & trend: Limited evidence or limited consensus
• 2011 • Connectivity – recruitment, settlement
Assessment grade: Good
Assessment trend: Stable
Confidence grade & trend: Limited evidence or limited consensus
• 2011 • Connectivity – genome structures, genetic adaptation
Assessment grade: Good
Assessment trend: Stable
Confidence grade & trend: Limited evidence or limited consensus

----------------------------------------

CHANGES SINCE 2011 SOE ASSESSMENT
Unclear how the 2011 assessment was done.

2016年《环境状况报告》（State of the Environment, SoE）的海洋章节整合了基于多股海洋数据流开发的多个专家模板。本元数据记录描述了题为《物理、生物地球化学及生物过程的状态与趋势——基于物理过程的海洋连通性》的专家评估报告。完整的专家评估报告（含已提供的图表）附于本记录之后。若有可用的、用于生成该专家评估报告的数据流，则可通过本记录的“在线资源”板块访问。

----------------------------------------

专家评估的生态过程描述
澳大利亚周边的海洋生物连通性由风、浪、潮汐和海流等物理过程驱动，这些过程在广泛的时空尺度上运作。这些水体运动携带并扩散对海洋生态系统功能至关重要的溶解性物质（营养盐和化学污染物）及颗粒物（沉积物、海洋垃圾和浮游生物）。高连通性会根据具体情况对生态系统组分产生正面或负面影响，低连通性（即高滞留性）亦是如此。例如，鱼卵和幼体从产卵场向育幼区的运输可能对繁殖成功至关重要，但也可能促进有害物种的扩散。

澳大利亚中陆架和内陆架的环流与连通性模式往往受风和潮汐主导，而近海环境则受主要洋流系统的强烈影响，包括西部向极地流动的利温洋流（Leeuwin Current, LC）及其沿澳大利亚南部海岸延伸至塔斯马尼亚的部分，以及东部的东澳大利亚洋流（East Australia Current, EAC）。这些洋流的强度随年代际强迫周期（如厄尔尼诺-南方涛动ENSO、南极涛动SAM、印度洋偶极子IOD）变化，且在部分区域存在与气候变化一致的长期连通性改变的证据。例如，东澳大利亚洋流（EAC）向南流动增强（Ridgway 2007）与近100个物种的分布范围大幅南扩相关（Frusher等，2014；Sunday等，2015）。这意味着澳大利亚东海岸南北生物种群间的连通性显著提升。相反，这种南扩可能降低了南北向的连通性。

----------------------------------------

专家评估所用数据流
已发表论文。澳大利亚联邦科学与工业研究组织（CSIRO）创建并维护用于研究扩散的模型（Bluelink——BRAN产品）。澳大利亚综合海洋观测系统（IMOS）持有海流强度数据，个体研究者持有目标物种数据。报告卡已开始明确将连通性作为指标纳入——http://ghhp.org.au/report-cards/2015/environmental。

----------------------------------------

2016年SoE评估摘要 [详见附随的专家评估报告]

• 2016年 •
评估等级：差
评估趋势：恶化
置信度等级：证据有限或共识不足
置信度趋势：证据有限或共识不足
可比性：等级与趋势无法直接与2011年评估结果比较
• 2011年 • 连通性——空间/物理间断
评估等级：优
评估趋势：稳定
置信度等级与趋势：证据有限或共识不足
• 2011年 • 连通性——生物、迁徙、迁飞路线
评估等级：良
评估趋势：恶化
置信度等级与趋势：证据有限或共识不足
• 2011年 • 连通性——补充、定居
评估等级：良
评估趋势：稳定
置信度等级与趋势：证据有限或共识不足
• 2011年 • 连通性——基因组结构、遗传适应
评估等级：良
评估趋势：稳定
置信度等级与趋势：证据有限或共识不足

----------------------------------------

2011年SoE评估以来的变化
2011年评估的实施方式尚不明确。