Black volcanic rocks spill onto the beach

There's a place to the east of Flynns Beach where a flow of volcanic rock has spilled down the land and into the sea. These black rocks make a dramatic statement, and also mark the place where two of our walks meet.

From home, when we walk west along 'our' beaches, the sand ends at this same spill of volcanic rock. From here you can also see the tiny Trenevan Park Chapel perched on the cliff -- a place where local weddings and funerals are often held.

While walking we keep our eyes open for treasures, and also for weeds such as this introduced sea spurge -- a nasty weed because it overtakes the sand dunes and also contains sap that's dangerous to human eyes and skin.

European sea spurge invades island beaches

Sea spurge is a small plant originally from Europe and now found throughout south-eastern Australia, including Tasmania and the Bass Strait islands. It's a plant that likes sandy beaches and dunes.

A single plant is able to produce up to 5000 salt-tolerant seeds every year. These seeds spread widely in wind and ocean currents. Consequently, colonies can increase in size rapidly, and in the space of a few years a beach can be overrun by sea spurge.

Sea spurge (Euphorbia paralias) is a true invader, crowding out indigenous plants and reducing the places where sea birds can nest -- especially hooded plovers that prefer open sand for nesting.

Broken stems and leaves ooze a toxic milky sap that burns exposed skin and may cause damage to eyes. For this reason, it's advisable to wear gloves and protective clothing when pulling out and bagging this weed.

Situated close to our home here on Phillip Island, lies a small sandy cove surrounded by stunning red cliffs. On the eastern tip of this cove is Grossard Point with its shipping beacon.

The vegetation within this cove is free of all weeds except sea spurge. Doug has decided that he'll pull out and bag the six patches of sea spurge with follow-up weeding over the next five years or so. Seed heads explode when mature -- in late summer -- releasing their seeds. No doubt there's a lot of seed lying dormant in the sand, ready to germinate next year.

This year will be the most difficult because some of the plants are several years old. Mature plants have long tough tap roots that cling tenaciously to the ground and are difficult to pull out. Doug is a strong, however, and determined to return the vegetation of this unique cove to its original condition.