David Griffin - CSIRO Marine Research, Hobart Australia
Alan Pearce - CSIRO Marine Research, Perth Australia
John Wilkin - NIWA, New Zealand
More larval Western Rock Lobster survive the 9-month larval phase in years when sea level at Fremantle is higher than usual. But why? Many things correlate with sea level, the strength of the Leeuwin Current being only one of them. We are focussing on the potential role of larval advection now that satellite altimetry makes mapping the complex eddy field of the Leeuwin possible. Preliminary results are fascinating. As envisaged some time ago, the balance between northward summer winds and onshore/southward currents is very important. But so are the eddies. Model phyllosoma (and real drifters) get trapped in cold core eddies (we don't know if real phyllosoma do), and eddies of either type can slingshot phyllosoma shoreward from 500km offshore. Less model phyllosoma are lost forever to the deep ocean in years when observed larval recruitment was high, and vice versa. This is encouraging, and we are not finished yet.