Could the already-decimated Southern bluefin tuna population be about to be devastated for good by the Montara oil spill? Crikey’s crack graphics department has uncovered some eerie parallels between the slick’s current satellite status and the spawning zone for the prized high-value fish, which this week had its Australian quota cut by 25% amid tumbling global stocks.

Here’s the latest satellite image of the Montara slick:

And here’s the Southern bluefin tuna’s spawning zone:

According to experts on the ground, with the spawning season for Southern bluefin stretching from September to April, the key question is what is happening to the oil below the surface, and how that might pose a risk to spawning fish.

Gilly Llewellyn from the World Wildlife Fund, who recently returned from the slick zone, told Crikey: “certainly with the perilous status of the Southern bluefin tuna population it would be a huge concern if the slick were to cause additional pressure and risk of recruitment to a population that is literally decimated”.

Any further reduction in the stock is likely to hit smaller fishing operations hardest, who under the new international guidelines are required to reduce their catch by 25%. Bigger operators, whose owners are starting to feature on the nation’s rich lists, can simply pass on any quota reduction to Japanese consumers in the form of higher prices.

Concern has also been raised over other fish species, including the gold band snapper, which has a spawning season of January to April, and the Red Emperor, which is spawning now. Whale sharks, the basis of a multi million dollar tourism industry in WA, are also believed to swimming through the slick zone.

A fourth attempt by Thai company PTTEP to plug the leak has proven unsuccessful, according to a report this morning. There are also reports that oil-affected seaweed is starting to wash up on the Indonesian island of Roti.

Around 400 barrels of oil a day has been leaking into the Timor Sea after the leak sprung nine weeks ago. The Australian Maritime Safety Authority has been using dispersants in an attempt to clean-up the spill, but is yet to make much of an impact.

Crikey understands that Greens Senator Rachel Siewert is likely to raise the issue of the slick again today in Parliament.