Water Quality

The health of coral reefs and other tropical marine ecosystems depends on the quality of the water that surrounds them. Sedimentation and turbidity, nutrient availability, amounts and types of organic matter in the water, contaminants, salinity, temperature and alkalinity can all strongly influence the productivity, resilience and function of coastal and coral reef ecosystems.

Increasing human population, intensifying land use and development of coastal regions are the primary causes of decline in coastal water quality and ecosystem health. The main marine water quality issues facing the waters around Northern Australia are:

• increased loads of suspended sediment, nutrients and contaminants entering coastal waters from the adjacent land as a result of agricultural activities and industrial and urban development, which have can adversely affect marine organisms including coral reefs.
• the impact of rising seawater temperatures and increasing seawater acidity as a result of enhanced inputs of greenhouse gases to the atmosphere and the enhanced uptake of carbon dioxide (CO²) by the oceans. Increased acidity of seawater reduces the capacity of corals and other calcifying organisms to build their calcium carbonate skeletons, shells and scales, which also form reefs and sediments.

Read more about these issues here.

AIMS studies water quality and the movement of water, nutrients and sediment in our tropical marine environment, as well as monitoring water quality and the health of inshore reefs of the Great Barrier Reef. It also investigates the responses of reef organisms to water quality and develops indicators and bioassays for reef organism health, and conducts for assessments of the environmental footprint of aquaculture and other coastal industries.

Photo: Ray Berkelmans.

October 30, 2009