Why It's Important To Release All Big Fish

by Greg Vinall | ALF

Why Is It So Important To Release The Really Big Fish?

Over the last couple of weeks I’ve clashed a couple of times with an angler who made the call to knock a very large old girl flathead on the head. The excuses and justifications for this act of extreme selfishness were wide and varied, ranging from “my grandfather would be proud” to “there are heaps of these big fish in that system to “fish that size are past their prime as breeders and of course “The law says I can, so I’ve done nothing wrong”.

Polite attempts to draw attention to the science that refutes these claims received the response “anyone who has been fishing this system as long as I have knows that’s wrong.

Obviously, with extremely selfish and short sighted individuals such as this, pointing at facts is a waste of time – their only concern is for themselves and they’ll do whatever they want, to hell with everyone else. But for those who genuinely do care about the future of fishing in Australia, here are my responses to some of the more ridiculous arguments that were thrown up. BTW, this discussion was focused on flathead, but I reckon the same applies to the big individuals of any species we catch (except on those odd occasions where the fish won’t release well):

Flimsy Excuse #1: “There’s no shortage of these big fish, we catch more big flathead today than when we were kids”.

That’s probably true. And if so it’s because the majority of anglers are considerate enough to put those trophy fish back. I know anglers who have tagged flathead and recaptured them personally 3-4 times, or others have caught the same fish. These days the majority of anglers understand the importance of these big individuals (yes, even though they’re not always protected by law). You, on the other hand, just prevented any other anglers from catching, enjoying and releasing that fish again. Clearly, if the masses were to revert to this kind of behaviour those trophy fish would again become depleted.

Flimsy Excuse #2: “The really big fish are past their prime as breeders and you improve recruitment by removing them from the system”.

Please. Really? The fecundity (ability to produce good numbers of viable eggs) of some species may decline when fish get really large, perhaps. Or not, I haven’t spent a huge amount of time researching it. But there is plenty of published scientific evidence that the potential fecundity of flathead continues to increase irrespective of size and that the relative fecundity stays constant for their whole lives. What does all that mean? It means that the bigger the flathead, the more eggs it produces, full stop.  And that a 1m fish can easily produce as many VIABLE eggs as 8 or 9 fish of 42cm length. In fact, a recent University of Queensland study showed that flathead of 75cm and longer contributed 13% of the juvenile fish recruitment, yet themselves were less than 10% of the flathead population. Big fish are important breeders.

Flimsy Excuse #3: “Smaller, younger fish are more likely to produce viable eggs”

I think I already answered this above…… but let me give you one more thought. When you want to breed a winning racehorse you breed two winning horses. When you want a good working dog you breed two good working dogs. And your best chance of having trophy fish is if the biggest specimens remain in the system to breed. By removing big fish from the system you are artificially removing the genes for long life and large size. And you are favouring the breeding of smaller fish. It’s a lose-lose situation all round for the future of fishing.

Want some more reading on flathead breeding?



Greg "Doc Lures" Vinall

Greg "Doc Lures" Vinall

Podcast Host, Lure Maker, Scientist, Educator

Greg is host of the Australian Lure Fishing Podcast. He’s an Aquatic Scientist, Lure Maker, Speaker and Author in the recreational fishing space. 

Subscribe To ALF

Apple  |  Stitcher  |  Google  |  Spotify  | iHeartMP3