A new study by researchers from the University of Adelaide have discovered that playing the sounds of healthy noisy reefs successfully attracted oysters to areas undergoing restoration work. The team amplified recordings of healthy Port Noarlunga Reef in South Australia through marine speakers at two newly constructed boulder reefs offshore from Adelaide and the Yorke Peninsula.
Like humans attracted to the sounds of a swinging party, the oysters flocked to the noisy reef soundscape. Sites using the speakers attracted hundreds and at some sites thousands more oyster larvae to settlement panels. Another benefit was that large oysters, which are favoured for their ability to create increased reef coverage, were attracted by the sounds and settled in significantly bigger numbers.
In water where visibility is low, sound is an important tool for new oysters searching for a stable home. Oyster larvae do not have ears and instead they have a statocyst. About the width of a human hair, the statocyst is extended in front of the oyster larvae as it swims. This tiny sensory hair helps it to navigate through the water and filter the sound assisting it to remain balanced and orientated.
This discovery to fast-track oyster recruitment using sound is exciting as it increases the efficiency of habitat formation. Using this strategy, oysters could outcompete turf-forming algae that can quickly smother new reefs. Fast recruitment to restoration sites could also offer other benefits like reducing the need for high costs associated with ongoing manual intervention, freeing resources for other tasks.
Known as the ‘ecosystem engineer’, oysters play an essential role in filtering water in our oceans and river systems. To speed up the restoration of marine environments we will need efficient strategies like underwater speakers to attract and quickly establish oysters in quantities to maintain new reef viability. Although an adult oyster can filter as much as 50 gallons of water a day, approximately 13,200 adult oysters would still be needed to clean the water of one Olympic sized swimming pool.
Oysters not only clean the water but also build three-dimensional habitat favoured by crabs and small animals that attract fish and larger creatures who feed on them. The broader benefits to ecosystems delivered by restored oyster reefs have been recognised by communities in Australia and overseas motivating projects to restore oyster populations in various locations. For example:
In Moreton Bay, Queensland, oyster shells have been cleaned and used to assist organisers build new reefs in their efforts to restore 100 hectares.
In Belfast Lough in Northern Ireland, oyster nurseries are being installed underneath pontoons after the recent discovery of live native oysters thought to be extinct.
In New York, USA, school children and volunteers have already restored oysters to 15 sites as part of efforts to restore 1 billion oysters by 2035.
Do your part to keep our waterways clean
Carefully dispose of rubbish so it doesn’t end up in waterways and
if you see oysters on the menu at a restaurant, ask wait staff whether the restaurant composts or recycles empty shells.
Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.