This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A discovery has led to the first confirmed records of recreational catches of Pacific bluefin tuna (Thunnus orientalis) in Victorian waters. The breakthrough came after two large tuna caught off Bass Strait in July 2026 were genetically tested and confirmed as Pacific bluefin tuna, a species rarely recorded by Australian recreational fisheries.
The fish were caught just days apart by Victorian anglers fishing far offshore from Western Port Bay at depths of 50–60 m (164–197 feet). One fish weighed approximately 165 kg (364 pounds) and measured 2.12 m (7 feet), while the second weighed 131.6 kg (290 pounds) and measured 2.02 m (6.6 feet). Initially, both fish were assumed to be southern bluefin tuna (Thunnus maccoyii), a species commonly targeted by recreational game fishers in Victoria and more commonly associated with Australian waters.
However, Tuna Champions scientific ambassador Jonah Yick and experienced fisher Dave Standing, along with a few other fishers, noticed several unusual features on the fish that raised questions about their identity. "The fact that these two fish were caught in close proximity, literally on Melbourne's doorstep, within 10 kilometers (6.2 miles) of the shoreline, is an amazing catch and story," Yick said. "The Pacific and southern bluefin tuna look very similar to the naked eye, but there are subtle differences which can be used to distinguish between the two species, which include anal and second dorsal fin length, markings on their skin, body shape and average size." Pacific bluefin tuna have been caught by longliners (or commercial fishermen) in Victorian waters, but they are usually in very deep water, a long way from shore.
Recognizing the potential significance of the catches, Standing quickly contacted the anglers involved in both catches and coordinated the collection of muscle samples for genetic testing. The samples were then sent to Yick, who subsequently passed them on to principal research scientist Dr. Peter Grewe—the lead geneticist working on tuna genomics at CSIRO in Hobart.
Grewe ran an initial DNA screen using a rapid tuna species identification test developed at the CSIRO labs. The results indicated both fish were Pacific bluefin tuna. This was a significant finding, as these captures represent the first genetically confirmed Pacific bluefin tuna caught by recreational fishers in Victoria.
"I'm extremely confident in these results following a secondary forensic-grade sequencing analysis further confirming our initial quick species ID test," Grewe said. Months later, anglers off Lakes Entrance, Victoria, began catching large numbers of tuna weighing between 130 and 217 kg (287 and 478 pounds). Preliminary assessments based on external features suggest these fish may also be Pacific bluefin tuna.
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