Biodiversity, and the factors controlling it, for selected habitats in the Timor Sea region: Physical Oceanography of Karmt Shoals

Despite the major marine bioregions being broadly identified in north western Australia, there has been limited observation and documentation of the marine biodiversity present. The Oceanic Shoals bioregion, which includes numerous shelf edge reef systems, has been identified as a biodiversity hotspot for at least some major taxa, such as sponges, but past research has largely focused on the emergent reef systems at the western end of the bioregion. However, the most common reef types in the Oceanic Shoals bioregion do not reach the sea surface. These submerged reefs, which are biogenic in nature and rise out of deep water to between 10-50m below the sea surface, are very poorly understood and remain mostly to be explored and characterised. As mini seamounts, these reefs may well be areas of both biodiversity and biomass accumulation. The initial task for biodiversity surveys will be a census of submerged reefs to characterise the biodiversity, including its spatial pattern of habitats within reefs, then develop a regional model for habitat types and the location of any diversity hotspots. Integration with data on chemistry, oceanography and geology will be a feature of the Timor Sea study and will permit targeted multidisciplinary projects seeking to understand the processes that sustain the biota of the region. To this end, the distribution of shelf edge upwelling phenomena and natural hydrocarbon seeps, both potentially significant attributes of the bioregion, will be investigated and integrated with data on biodiversity patterns. This report summarises the deployment of 2 instrumented moorings in 50 and 100m water depth near Karmt Shoals in the Oceanic Shoals Bioregion of the Timor Sea. Moorings were set in January 2004, recovered and redeployed in April 2004, and finally recovered in December 2004.

尽管澳大利亚西北部的主要海洋生物区（marine bioregion）已被大致划定，但当前对该区域现存海洋生物多样性的观测与记录均较为匮乏。浅滩洋域生物区（Oceanic Shoals bioregion）包含众多陆架边缘礁系统，已被认定为至少部分主要生物类群（taxa，如海绵（sponges））的生物多样性热点区域，但过往研究大多聚焦于该生物区西端的出露礁系统。然而，浅滩洋域生物区中最常见的礁体类型并未出露于海面，这些生物成因、从深水区抬升至海面下10至50米深度的隐没礁体，其相关认知程度极低，大部分仍有待勘探与特征厘定。作为微型海山，此类礁体极有可能是生物多样性与生物量富集的区域。本次生物多样性调查的首要任务为对隐没礁体开展普查，以明确区域生物多样性特征，包括礁体内部生境的空间分布格局；随后需构建生境类型与潜在生物多样性热点区域位置的区域模型。与化学、海洋学及地质学数据的整合将是帝汶海研究的一大特色，此举可支撑针对性多学科项目，以解析维持该区域生物群落的相关过程。为此，本研究将调查该生物区两项潜在重要特征——陆架边缘上升流现象与天然烃类渗漏的分布情况，并将其与生物多样性格局数据进行整合。本报告概述了在帝汶海浅滩洋域生物区（Oceanic Shoals Bioregion）卡姆特浅滩（Karmt Shoals）附近50米与100米水深海域部署2台搭载观测仪器的锚系浮标（instrumented moorings）的情况。该锚系浮标于2004年1月布设，2004年4月回收并重新布设，最终于2004年12月完成回收。