permits acquired!

Exciting news – our permit to conduct scientific research in Coffin Bay’s sanctuary zones has been approved! That means we can start collecting the scientific data needed to inform how and where we can restore Coffin Bay’s lost reefs.

Most importantly, we need to know where and when the larvae of native angasi oysters are recruiting across the bay. This is vital knowledge if we are to help those baby oysters to form new reef habitat, which provides the foundation for oyster reef ecosystems.

When environmental conditions are right, adult angasi oysters can release up to 3 million larvae into the water to disperse and, hopefully, find a new home. Angasi larvae can spend up to 2 weeks floating in the water column, dispersing primarily via tides and currents (but also swimming! a little). When the larvae interpret certain ‘environment cues’, such as attractive smells (of other oysters) or sounds (of healthy habitats), the larvae can sink to the seabed and cement itself to a rock or shell to begin their sessile (stationary) life. This process of ‘recruitment’ to the seafloor is the biggest bottleneck in the life of an oyster – only a small portion of the larvae released by adult oysters will find a place to live. This is because oyster larvae need to find suitable hard substrate (rock, shell) to settle on, but almost all of the seafloor has changed from historical oyster reefs to sediment.

Excitingly, right now conditions are ideal for adult oysters to start spawning. Previous research shows that angasi oysters start spawning larvae once water temperatures exceed 17oC. So, this is the perfect time to put our oyster settlement panels and bags of oyster shell into the water, on which the oyster larvae will settle so can learn where they are recruiting, and when.