Assessing the threats to Torres Strait water quality and the implications for ecosystems and pubic health

The Torres Strait is a region dominated by marine environments that provide resources for local communities and have important social and cultural values. The condition of marine water quality can influence marine foods, human health, marine ecosystems and ecological processes in the region.

Previously, no detailed water quality hazard analysis was done for the region, however, potential issues were identified, including regional pollution linked to mining, port developments and land clearing, primarily in Papua New Guinea; more localised pollution from sewage and stormwater discharge; and pollution directly and indirectly associated with shipping, including marine infrastructure.

A Tropical Ecosystems Hub project lead by the TropWater team at James Cook University described all existing and potential sources of pollution and associated risks to the Torres Strait marine environment and public health. The information was documented to facilitate uptake of findings to key research users, and to design a basic monitoring program that measures the success of pollution management in the Torres Strait.

The project team developed a hydrodynamic model to better understand the dispersal of different water borne pollutants and the associated risks as many of the pollutants are large scale and mostly derived from outside the Torres Strait region. The model revealed variable flushing, including highly energetic small-scale flow dynamics near shoals, reefs, islands and passages, while water tends to stagnate in other areas where pollutants, including metals, may accumulate.

The project found that, whilst there are a number of local pollutant sources that may pose a risk to marine ecosystems and foods in the Torres Strait, the largest threats come from beyond the region and are compounded by the potential risks associated with the transit of large ships.

Information on the current status and future potential of pollutant sources in the region is now available in a spatial database.

Jon Brodie & Jane Waterhouse, TropWater, JCU