IMAS - SMRCA
IMAS researchers are currently re-surveying populations of the sea urchin Centrostephanus rodgersii and associate sea urchin barrens along Tasmania’s east coast.
The research will assess the range extension and impacts on kelp bed habitats relative to an identical FRDC baseline survey in 2001/02.
The re-survey consists of 156 diver transects spanning 13 regions in eastern Tasmania - from Eddystone Pt in the north to Recherche Bay in the south. In addition to the dive surveys, 156 towed video surveys, covering approximately 80km of coastline, are being recorded and assessed.
Click here or on the image below to watch video contrasting kelp forest with an urchin barren (Credit: Scott Ling).
This systematic survey will quantify trends in the Centrostephanus populations across eastern Tasmania, allowing for future trends and region-by-region predictions of overgrazing to be estimated. Furthermore, trajectories for urchin populations on specific reefs that may be approaching the tipping-point of overgrazing can be identified.
The resurvey and assessment of urchin abundance against historical baselines will provide maps of change and an early-warning system of overgrazing to help prioritise tactical prevention (before barrens form).
Monitoring of change in sea urchin abundance, demography and the occurrence of incipient barrens patches will help safeguard collapse of kelp beds and the important reef-based fisheries (i.e. abalone and rock lobster) supported by kelp habitats.
The survey is due for completion late 2017.
Click here or on the image at right to watch a YouTube video of a rock lobster preying on an urchin (Credit: Scott Ling)
Click here to view IMAS publications relating to this research.
Interested in this project?