Sedimentology and Geomorphology of the East Marine Region: A Spatial Analysis

This report presents the geomorphology and sedimentology of the East Marine Region. The
three main outputs of the report include: 1) a review of previous geological research undertaken in
the East Marine Region (EMR); 2) the results of a quantitative study of seabed sediment texture and
composition for these regions; and 3) a synthesis of this information characterizing regional trends in
sedimentology, geomorphology and bathymetry. The study is a collaboration between Geoscience
Australia and the Department of the Environment, Water, Heritage and the Arts (DEWHA) and is a
continuation of similar work conducted for the North West Marine Region (Potter et al., in press;
Baker et al., 2008) and the South West Marine Region (Richardson et al., 2005). By combining results
of previous qualitative work and quantitative information generated from existing and new data, this
report provides an improved understanding of sedimentology for the EMR. Information contained
within this report will contribute to the Department of the Environment, Water, Heritage and the Arts
national work program and will also assist in the marine bioregional planning for the East Marine
Region.

Previous sediment studies in the EMR have predominantly produced qualitative results at local scales.
Geomorphic, sedimentary and biological information has previously been utilised to develop a
National Bioregionalisation of Australia's Exclusive Economic Zone (EEZ) (Department of the
Environment and Heritage (National Oceans Office), 2005; now the Department of the Environment,
Water, Heritage and the Arts) and substantive geomorphic features of the eastern continental margins
have already been identified and mapped (Heap and Harris, in press). This report adds
significantly to these previous studies by incorporating the information in a sedimentological
synthesis that includes a discussion of the implications for marine conservation in the EMR.
The physical characteristics of the seabed in the EMR, as described by the sediment texture and
composition data, can assist in determining the diversity of benthic marine habitats in the EMR. These
data represent enduring features which are elements of the physical environment that do not change
considerably and they are known to influence the diversity of biological systems. This is important
for marine conservation by contributing to the better definition and characterisation of benthic
habitats. Seabed texture and composition are easily measurable parameters that when combined with
other physical features can be used to create "seascapes" that serve as broad surrogates for benthic
habitats and biota (Whiteway et al., 2007). Seascapes have the potential to be used in informing the
marine bioregional planning process.

本报告阐述了东部海洋区域（East Marine Region，EMR）的地貌学与沉积学特征。本报告包含三项核心成果：1）东部海洋区域（EMR）既往地质研究综述；2）该区域海底沉积物纹理与组分的定量研究结果；3）整合上述信息，总结该区域沉积学、地貌学与海底地形的区域变化趋势。本研究由澳大利亚地球科学局（Geoscience Australia）与环境、水、遗产与艺术部（Department of the Environment, Water, Heritage and the Arts，DEWHA）合作开展，是对西北海洋区域（Potter等，即将出版；Baker等，2008）及西南海洋区域（Richardson等，2005）同类研究的延续。本报告通过整合既往定性研究成果，以及由现有及新增数据生成的定量信息，深化了对东部海洋区域（EMR）沉积学特征的认知。报告所载内容将助力环境、水、遗产与艺术部的国家工作规划，同时可为东部海洋区域的海洋生物区划规划提供技术支撑。

此前针对东部海洋区域（EMR）开展的沉积物研究，多仅在局域尺度上生成定性成果。此前，地貌、沉积与生物信息已被用于构建澳大利亚专属经济区（Exclusive Economic Zone，EEZ）国家生物区划（环境与遗产部（国家海洋办公室），2005；现为环境、水、遗产与艺术部），东大陆边缘的主要地貌特征也已被识别并绘制成图（Heap与Harris，即将出版）。本报告通过将相关信息整合至沉积学综合分析中，并探讨其对东部海洋区域（EMR）海洋保护的启示意义，极大丰富了既往研究成果。

东部海洋区域（EMR）的海底物理特征可通过沉积物纹理与组分数据表征，有助于明确该区域海洋底栖生境的多样性。此类数据代表了物理环境中变化极小的持久特征，且已知其会影响生物系统的多样性。这一点对于海洋保护至关重要，因为它有助于更精准地界定与表征底栖生境。海底纹理与组分是易于测量的参数，将其与其他物理特征相结合，可用于构建海底景观（seascapes），作为底栖生境与生物类群的广义替代指标（Whiteway等，2007）。海底景观有望为海洋生物区划规划流程提供参考依据。