Why healthy wetlands are important for a healthy reef

This is a guest post written by Chelsea Broad. Chelsea attended the World Wetlands Day event put on by NQ Dry Tropics on Thursday 2nd Feb 2017. The views expressed in this post are the authors and not necessarily those of NQCC.

 

Photo credit: Chelsea Broad

World Wetlands Day works to educate the community on the issues facing the Great Barrier Reef (GBR) and inspire the community to take action to protect the GBR and associated wetlands. More than 50 community members participated in educational lectures from the Great Barrier Reef Marine Park Authority and the Australian Institute of Marine Science (AIMS) and tours of ReefHQ and AIMS, including the world class scientific laboratory, SeaSim, within the Townsville region.

 

Did you know that keeping inland wetlands healthy is crucial for protecting the GBR? This is because corals need sediment-free water to be healthy. Inland wetlands filter sediments out of the waterways prior to arriving to the ocean, providing the corals with sediment free water. Without healthy wetlands, the GBR is at risk of increased sediment exposure. The radiant reef ecosystem pictured here is located at AIMS to educate guests on what a healthy outer reef looks like. 

Photo credit: Chelsea Broad

AIMS also provide examples of unhealthy reefs, including algal based reefs, and crown-of-thorns invaded reefs.  Nutrients and sediments cause water quality to decrease, and in turn the habitat becomes more favourable for algae to live. As algae grows, it prevents coral polyps from finding a suitable location to settle. This will eventually lead to a phase shift from a coral based reef system to an algal based system.  The increased amount of algae also promotes the growth of pest species such as crown-of-thorns seastars.  This happens because young crown-of-thorns need algae to live, thus with an increased amount of algae available more young crown-of-thorns are able to reach adulthood. Within the past 30 years, crown-of-thorns have been responsible for destroying about 1/3 of corals on the GBR.

Photo credit: Chelsea Broad

Apart from the corals, other marine animals are at risk from declining health of the GBR ecosystem. Green Sea Turtles, like this one pictured enjoying a back-scratch, are at risk from decreased water quality. Pollutants in the water cause the animals to become stressed which makes them more susceptible to viruses like Fibropapilloma. You can learn more about sea turtles and the threats they are facing at the Turtle Hospital located at ReefHQ.

 

Many other species rely on the healthiness of the reef to survive. This includes various species of seastars, marine snails, sharks and fish species. Many fish species such as the Red Emperor and Mangrove Jack rely not only on the reef, but on inland wetlands as well for their reproductive cycle. The inland catchment and wetlands are at risk from increased grazing pressures, urbanization, infrastructure and decreasing ground water from the use of irrigation.  Scientists and farmers are working together to come up with new solutions to restore natural hydrological regime, while allowing the farmers to remain profitable. One method that is currently being tested is feeding cattle approximately 10% algae. This has been shown the reduce methane released from the cattle, while also reducing the amount of algae on the reef.

You can stay up to date with the health of the GBR in your area by referencing an annual report card prepared for the reef. The report card includes information on the state of corals, the state of sea grass, and water quality.