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.