Port Phillip Baykeeper » Education

Blue-ringed Octopus – seashell surprise

BayKeeper — Fri, 08 Jan 2010 02:33:46 +0000

Investigating our amazing coastal plants and animals is a cool way to spend summer. But bear in mind you’re entering their home… so mind your manners! Stay safe, be careful where you tread, and leave the environment in as good a condition as you found it.

Don’t put your fingers and toes anywhere you can’t see; and before you pick up a shell, check first to see if there’s an animal in it. Once vacated by the original owners, shells can be used as daytime hide-outs by a range of small creatures, including Blue-ringed Octopus.

B-rO bobs up in a bucket

The animal pictured above is quite small (its head only about 10mm across) and was unknowingly put in the bucket (probably inside one of the Turban shells). Luckily, it came out to be seen before any incident occurred. The animal and the shells were returned to the Bay.

Despite the millions of beach visits each summer, there are only 2 people known to have been killed by B-rO’s. They’re shy animals that will avoid people if they can. So take care to avoid them. If you don’t mess with them… they won’t mess with you!

Find a shore thing on a beach near you

BayKeeper — Sun, 20 Dec 2009 02:02:15 +0000

Most Australians remember fun days at the beach: beating the heat, building sand castles, catching frizbees and waves, and listening to the ocean in a seashell.
Perhaps that’s why it’s called the Lucky Country!

Thanks Douglas for sending the photo above. Anyone who takes a closer look on their favourite beach might find one of these and more. Each beach has its own story to tell. What sort of animal lived in this shell? How do they earn a living? Where do they fit in the food chain (what do they eat; and what eats them)? Do they know that by digesting and cycling nutrients they maintain healthy water for us? What do we do to the water?

Baykeeper will continue exploring beaches around the Bay in 2010 and invites you to join the growing movement to better understand, enjoy, and protect our coastal playground. Baykeeper activities in January (listed in the ‘events’ page of this website) are presented as part of the Coast Action Coastcare Summer by the Sea program.

Revised method to age Anchovy

BayKeeper — Sat, 28 Nov 2009 22:21:57 +0000

The Baywide Anchovy Study Milestone Report #1 (2008) caused great concern when it found a total absence of first year Anchovies in Port Phillip Bay. This lead to speculation that Anchovy recruitment had failed in 2008, with potentially dire consequences for the many other species that feed on them.

However, the Baywide Anchovy Study Milestone Report #2 (released in November 2009) concludes that first year Anchovies were in the Bay all the while, but their age had been over-estimated by one year. This conclusion was reached by microscopic examination of annual growth rings on Anchovy otoliths (bony plates around 1mm long found in the ear of the fish). Previous study of PPB Anchovy ageing was limited to work in the 1950s that used scale structure to determine age.

Congratulations to the Fisheries Victoria scientists for this new, fiddly and time-consuming study; an invaluable investment to understand our fish stocks and their habitats. The Baywide Study also reported that most Anchovies are believed to move out of the Bay into offshore waters as 1+ (second year) fish where they mature; eventually entering the Bay to spawn between October and April.