Marine and Coastal Theme

The seas off the South Coast of Western Australia have a relatively high level of biodiversity and marine habitats for temperate waters. The marine biodiversity is influenced by variations in the warm Leeuwin current, its mixing with cold counter currents and the effect of Southern Ocean swells. The marine floor also has diverse geology leading to variation in habitat. Most of the marine waters have not been well surveyed and so there is relatively little information on the biodiversity. Dynamic coastal processes shape inlets and estuaries with movements of large volumes of sand. The sheltered estuaries and their vegetation are important in fish recruitment and for migratory shore birds. Most estuaries have catchments cleared for agriculture and this has led to increases in sedimentation and an excess of nutrients. Estuarine and near coastal recreational and commercial fishing are important in the region. There is increasing pressure from coastal development and recreational use of beaches. These activities disturb coastal ecosystems and damage dunes. There is poor understanding of the importance of beach and dune biodiversity. There is a major threat to coastal ecosystems from rising sea levels and associated storm surges. There are a number of threatened marine vertebrate fauna using the coast and near shore islands.

Coastal Management

Background

The greatest proportion of the Great Southern population lives on the coast and there is increasing development pressure in most coastal areas. Integrated coastal management is an approach that considers the link between the coast and land and marine management. Effective coastal management is dependent on a good understanding of the physical dynamics of coastal processes but it also involves an understanding of human impacts and ways to manage human activities. Many of the catchments draining to the coast in the Great Southern are cleared for agriculture; so coastal management science needs to also consider the impact of upper catchment activities on estuarine and marine ecological and social and economic values.

NRM problem: The increasing use and development of the coast is resulting in degradation. Land use management in the catchment also impacts on coastal values. There is a need for better information for adaptive management.

Research objectives

  • Better understanding of coastal dynamics
  • Understanding the relationship between sandbar management and estuarine and shore ecology
  • Monitoring the ecological impacts of coastal and estuarine use/industries
  • Monitoring the ecological impacts of coastal access to dunes, coastal erosion
  • Understanding the impact of catchment scale management on coastal and marine values

Marine Species and Habitats

The Marine Futures project mapped 130 square kilometres at Mt Gardner and some areas at Point Ann but there is still insufficient knowledge of the marine resource. It is important to have indicators of the condition of the marine resource off the south coast in order to determine the effectiveness of natural resource management.

NRM Problem: There is insufficient knowledge of marine habitats and species to determine resource condition change.

Research objectives

  • Mapping of marine habitats, diversity and distribution using a range of tools
  • Understanding the effect of catchment management on marine systems
  • Surveys and monitoring of human impacts on marine birds, mammals, crustaceans and finfish
  • Social and economic aspects of management of demersal finfish stocks
  • Understanding and monitoring the impact of marine pests

Marine Reserves/Protected Areas and Marine Planning

Background

Both the State and Commonwealth governments are conducting broad scale marine planning and there are proposals for some protected areas. The most important research on any proposed marine protected areas is on their potential impact on ecological and socio-economic values.

NRM problem: Marine planning needs to consider ecological and socio-economic values.

Research objectives

  • Better understanding/documentation of socio-economic implications of marine protected areas
  • Monitoring the biological responses to any marine protected areas
  • Understanding/documenting the economic, social and environmental values of marine, coastal and estuarine systems to assist planning

Seagrasses

Background

Seagrasses are an important habitat for many other species including commercial finfish and they also stabilize sediments.

NRM problem: Seagrass decline.

Research objectives

  • Monitoring the impacts of human use on seagrass decline
  • Improving seagrass regeneration methods

Climate Change

Research objectives

  • Understanding the impacts on the interface between salt water and fresh water e.g. estuaries
  • Understanding the impacts on foreshores