Because bull sharks have a knack for swimming up river, they tend to make big, fearmongering headlines. The latest "monster shark" alert revolves around a 300-kilogram (600 lb) animal caught in the Hastings River by an Australian fisherman earlier this year. While this is undoubtedly an impressive shark, as in most cases, there's no reason to panic. 

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Image: Denis Rivers/Facebook

Contrary to some reports, this was no random catch. The man who reeled in the animal on the Mid North Coast of New South Wales, Denis Rivers, is a sport fisherman who specialises in landing big game, including sharks.

I met Denis Rivers this year when we released Volume 1 of our Shark fishing DVD ,at the stage he was getting into...

Posted by Yep,I'm On Fishing on Wednesday, December 9, 2015

 

While the animal was eventually released, it's important to note that long battles (Rivers wrestled with his catch for a full hour) cause elevated stress levels that can be fatal to sharks – even if they make it off the line. Some species, like the endangered hammerheads, are extremely sensitive to this kind of fishing pressure. That's why scientists who tag and track these animals often limit their workups to just a few short minutes. 

Should you find yourself in a similar situation – accidental or not – the best course of action is just to cut the line (even if that means forgoing your shark selfie).

So, what was such a big animal doing in the Hastings River? We tend to think of sharks as ocean dwellers, but like saltwater crocodiles, bull sharks can adjust their biological processes to increase salt retention in fresh or brackish waters. They do this for a number of reasons, including finding food, but the Hastings River visit was likely related to breeding. 

"They often come in from the ocean and swim up the river to drop their pups and then go again," Rivers told GrindTV. "She was pretty fat in the belly so I reckon she might have been coming up the river to [do so]."

The sighting was really nothing out of the ordinary, and to date, there have been no reports of human-shark conflict on the Hastings River.