Looking back at a recent snapper season in Port Phillip Bay.
Fishing enthusiasts chasing snapper in Port Phillip Bay in the coming season could end up with a smaller haul than recent years, according to a leading fisheries scientist.
But while catch rates are expected to drop and some fishermen might find it harder to nab a snapper than previous years, the fishing is expected to be good and there will still be big snapper in the water.
"There's still going to be some pretty good numbers of big fish out there, but we're coming off a period for the fishery which by all accounts was the best it's been in 20 to 30 years," said Paul Hamer, senior research scientist with Fisheries Victoria.
Snapper success in Port Phillip Bay. Picture Tom McKendrick.
Dr Hamer said anglers had enjoyed a peak in the bay's snapper fishery over recent years, but that peak had now passed.
"We're starting to say that the fishery catch rate should drop down a little bit this year. It started dropping last year I think," he said.
"I'm expecting that there will be a decline in the catch rates...The fishery will drop down a bit now and then it will stabilise, and then we expect it will just go up a little bit more again in the next 10 years," he said.
Dr Hamer's comments are based on long-term research. In late March each year he conducts extensive survey work to establish the prevalence of baby snapper in the bay's key snapper nursery grounds.
A baby snapper. Picture courtesy Fisheries Victoria.
"The snapper fishery itself, the population is a combination of past spawnings. What's driving the fishery now is what happened five to seven years ago," he said.
In 2003-04 he found a record 15 baby snapper per 1000 square metres, on average. And in 2000-01 the average was eight. These snapper reached adulthood after six or seven years.
So as those fish got older, got caught by fishermen or died, the influence of spawning in those years has declined. But the fish that are still around from those years will be large fish.
The number of baby snapper found in the years since has been well below the 2003-04 spike. On average, three baby snapper are found per 1000 square metres.
Senior research scientist Paul Hamer and Camille White. Picture courtesy Fisheries Victoria.
Spawning success was above average in 2008-09, 12-13 and 13-14. But the latest research, from 2015, revealed that snapper spawning effectively failed in 2014-15.
The average number of baby snapper observed per 1000 square metres was 0.3. In peak years as many as 40 baby snapper per 1000 square metres have been recorded.
With the much-anticipated Port Phillip Bay snapper season fast approaching, fisheries authorities have urged anglers not to be alarmed by the latest research.
Travis Dowling, executive director of Fisheries Victoria, said fluctuations in spawning success rates were normal in wild fish populations. He said scientists had conducted baby snapper surveys in the bay for more than two decades, and knew to expect variation in spawning success.
"We are fortunate that this lower spawning year follows two very successful spawning seasons for snapper, which will ensure the fishery remains productive for years to come," he said.
"The surveys indicate low spawning success is more common than high spawning success, but the snapper fishery can remain strong with only a few highly successful spawnings each decade," he said.
The season for targeting adult snapper in the bay runs from about mid-October to early January. It is such a popular past-time, that fishermen joke you can walk from one side of the bay to the other on Melbourne Cup weekend without getting your feet wet, by stepping from boat to boat.