THE number and size of fish caught by anglers in Port Phillip Bay in Victoria remain at healthy levels, according to a recent dredging report. 

From January to April this year, information from more than 1000 boat fishing trips was recorded to provide valuable data on catch rates and fish populations.

Releasing results from the Baywide Recreational Fishing Surveys, environmental monitor Mick Bourke said the results were consistent with data dating back to 2003 and showed recreational catches in the bay were similar to previous years.

Mr Bourke said fish populations in the bay varied naturally and could be influenced by environmental conditions such as water quality, currents and habitat availability, all of which could be affected by dredging.

The program collects information on the bay's fish populations through on-site surveys of fish caught by recreational, boat-based anglers at 21 boat ramps across Melbourne, Mornington Peninsula, Geelong and the Bellarine Peninsula.

Information is collected on fishing trips including the locations visited, fish species targeted, the amount of time spent fishing and the number and size of fish caught. The key recreational species investigated are snapper, King George whiting and flathead.

The program runs year-round until the end of 2011. The next set of survey results should be released in December this year.

Fisheries Victoria executive director Peter Appleford said: "Boat ramp surveys of fish caught and kept by anglers over a period of 60 days identified there were no significant changes to catch rates of key recreational fish such as snapper and flathead.''

Meanwhile, a Fisheries Victoria workshop has found Port Phillip Bay is the most important spawning and nursery area for western Victorian snapper stocks, supplying most snapper found in Victorian waters west of Wilsons Promontory.

The workshop was convened in June to examine the latest research on Victorian snapper fisheries and to assess snapper stocks. Participants heard that two distinct stocks of snapper occupy Victorian waters - an eastern stock in waters east of Wilsons Promontory, and a western stock in waters west of Wilsons Promontory.

The workshop focused largely on the western stock where strong snapper recruitment since the early 1990s has probably contributed to the overall abundance of the fish in this area.

This has led to excellent recreational snapper fishing seasons and improved commercial snapper catches in the early and mid 2000s.

Dr Appleford said Fisheries Victoria intended to develop and seek stakeholder agreement on a formal snapper stock assessment and "adaptive'' management framework to keep commercial and recreational snapper fishing pressure at sustainable levels.