WAMSI 2 - Dredging Node - Project 9.1 - Effects of dredging related pressures on critical ecological processes for other organisms

Dredging is a common activity used for the development of marine infrastructure. It involves the physical removal of sediment from a dredged area in order to increase depth to allow for shipping, the laying of underwater pipelines and other port related developments. Dredging has significant effects on the marine environment, particularly the benthos, with direct and indirect impacts on marine flora and fauna. It is the key goal of dredging operations to reduce all potential impacts of dredging to acceptable levels. Two workshops were held: First from 29th – 30th November 2013 at CSIRO Floreat and the second from 22nd - 23rd September 2014 at CSIRO Floreat.The objectives of Workshops I & II were as follows:* identify the timing of critical ecological processes in tropical and temperate ecosystems with a focus on non-coral and non-fish biota (seagrasses, seaweeds, sponges, ascidians, bryozoans, molluscs, echinoderms, crustaceans and non-coral cnidarians);* identify environmental windows for critical ecological processes identified in Objective 1. This will be achieved by compiling information on the timing of reproduction, release of propagules and recruitment for these organisms, as well as the temporal and spatial scales of reproduction and recruitment events;* identify potentially critical periods (environmental windows) and locations when mitigating scheduling and processes could be employed to reduce the impact of dredging on non-coral and non-fish biota;* review the state of knowledge regarding potential effects of dredge-related sediments and other dredge-related pressures on these key ecological processes; and* identify the potential for invasive species to become established.The data product for this project is final report (.pdf).

疏浚是海洋基础设施开发领域常用的作业手段，其核心为通过物理方式清除疏浚区域内的沉积物，以提升水深，满足船舶通航、水下管线铺设及其他港口相关开发的需求。疏浚活动对海洋环境具有显著影响，尤其会作用于底栖生物（benthos），对海洋动植物造成直接与间接的干扰。将疏浚活动的所有潜在影响降至可接受水平，是疏浚作业的核心目标。

本次项目共举办两场研讨会：第一场于2013年11月29日至30日在CSIRO Floreat举行，第二场于2014年9月22日至23日在CSIRO Floreat举办。两场研讨会的目标如下：
* 明确热带与温带生态系统中关键生态过程的发生时序，重点聚焦非珊瑚、非鱼类生物群，包括海草、海藻、海绵、被囊动物、苔藓虫、软体动物、棘皮动物、甲壳动物及非珊瑚刺胞动物（cnidarians）；
* 确定目标1中识别出的关键生态过程对应的适宜环境窗口（environmental windows）。具体实现路径为：收集上述生物的繁殖、繁殖体（propagules）释放及种群补充（recruitment）的时序信息，以及繁殖与补充事件的时空尺度数据；
* 识别可通过调整作业时序与流程来降低疏浚对非珊瑚、非鱼类生物群影响的潜在关键时段（即适宜环境窗口）与区域；
* 梳理当前关于疏浚相关沉积物及其他疏浚相关压力因素对上述关键生态过程潜在影响的认知现状；
* 评估外来物种成功定殖的潜在可能性。

本项目的数据成果为最终研究报告（.pdf格式）。