The Cowderoy Street drain outfall crossing West St Kilda beach is an unlikely tourist attraction. But Baykeeper has found it brimming with fish during recent guided walks for Elwood Primary School families. Schools of juvenile Yellow-eyed Mullet ( Aldrichetta forsteri) and Small-mouthed Hardyheads (Atherinastoma microstoma) were regularly found. The recent recent rains have brought extra nutrients and oxygen to Bay estuaries… good news for fish!
High tide at Cowderoy - June 2010 (pic by Andrew McCutcheon)
Not surprisingly, the presence of these schools of small fish has put the local penguins in a pretty good mood. Earthcare St Kilda has recorded highest ever numbers of penguins breeding at St Kilda during the 2009-10 season, with the population estimated at around 1,200. At the same time, the average weight of adult penguins has been lower than usual, perhaps due to increased competition when finding a feed. The guided walks also found Nankeen Night Herons (Nicticorax caledonicus) patiently working the outfall.
It was great to see this life still in St Kilda despite the Port of Melbourne shipping channel dredging in the Lower Yarra River in recent years. The dumping of more than 3 million M3 of contaminated Yarra sediments in the bay may put the food chain, and particularly top order predators such as penguins at risk. The effects may take some time to show…. but so far so good!
