The Adventure of the day is something I've never done before – spearfishing for tilapia (an invasive pest species) in one of our local lakes in the Atherton Tablelands, Lake Barrine.

Lake Barrine
The lake itself is an extinct volcanic crater lake that filled with cool crystal clear water from rain and runoff over the 13000 years in which the lake was created . With a depth of approximately 65m, it is 1km in diameter and has a surface area of 240 hectares! Lake Barrine is well known for it’s lakeside teahouse where you can get a serving of their delicious scones and Devonshire tea, whilst overlooking the lake. The lake is now surrounded by lush tropical rainforest and you can do several walks around and near the lake. One of the best ways to see the lake is on a Lake Barrine Wildlife Cruise, which takes you around the perimeter of the lake to show you the special animals and plants that can be found here. Tours run four times a day: 9.30am (most recommended), 11.30am, 1.30pm and 3.15pm.

Tilapia
Tilapia belong to the Cichlid family of fish and are naturally found in the waters of South and Central America, southern India, Sri Lanka and Africa. In Australia, it is an invasive introduced fish species and was discovered in Lake Barrine in 2007. Tilapia competes with native species for food resources and space. Occasionally, tilapia has been known to prey on the eggs and fry of other fish. If not controlled, tilapia can establish large populations within a short period of time because of their high reproductive rates. Tilapia were first imported into Australia for the aquarium industry, and like so many other pest species, were most likely introduced to natural waterways through deliberate or accidental releases of fish intended for aquariums.

The Adventure
In Queensland, it is illegal to be in possession of a tilapia, dead or alive . This activity of spearing tilapia is an organised event through the Queensland Parks & Wildlife Service (QPWS) and is the only time you could be permitted to catch tilapia, without facing a fine. The fact that it is illegal to catch and eat tilapia is a topic of debate for many as it is thought that if people were allowed to catch and consume their catch (apparently good eating in some parts of the world), this would encourage people to catch and kill this pest. But the argument from the other side is that if it was encouraged to view tilapia as a food source then the tilapia population would be harvested and grown by the local community and would give this fish a "trade value", thus never eradicated. And if you think about it, while most would think catching, killing and eating the fish would bring numbers down, there will be some humans who think of nothing but the financial profit, so if there was some value to the fish, they would exploit this and instead of reducing current numbers, they would no doubt breed more tilapia for more financial gain – the exact opposite of reducing numbers. But like I said, this continues to be a topic of debate and great argument but for today’s event, we are legally permitted to catch and kill these little creatures and the QPWS disposes of them accordingly.

There is a great partnership with the QPWS and the Lake Barrine Wildlife Cruises, where they donate a boat for our use for the day so that we can assist to reduce the numbers of tilapia in the lake. All us volunteers pile onto the boat, armed with various spear guns and contraptions in which to bag our catch – some with regular catch bags, others with converted laundry baskets with floatation and lids! Some of us present today are first time spearos to spearing tilapia, others have been before and are on a mission to spear the highest number of fish for the day! To be honest, I didn’t think it would be that difficult to spear a small fish but here are the dilemmas I had:

1)      As I lined up my first fish, all the comments I had read on FB about “killing innocent creatures” played through my mind……so I actually struggled to pull the trigger on the gun as I looked into the little fish's eyes and thought “It’s not your fault you were born a tilapia!”

2)      After 10mins without a successful spear, I then thought “I can’t return to the boat without even one fish for the day! You’re here to eradicate an invasive fish species, it’s going to be really embarrassing when you return with zero!!”. So, I finally sucked it up and began really trying to spear fish.

3)      The little buggers are actually really tough!! When I actually started to aim at them and try to kill them proper, my first I don’t know how many shots, literally hit them and the spear tip would bounce off their bodies, sending little puffs of scales into the water where the spear made contact but didn’t penetrate or kill!

4)      I eventually got annoyed that I couldn’t spear these little fish even when trying so then I started to really commit to the kill and finally got some fish!! There are literally hundreds of tilapia in the small section of the lake I did see and they are everywhere! It was impossible to spear every fish in sight given the time it took to reload the gun each time and then free dive down to where the target was. But I think spearing is a good method as it allows you to specifically target an individual and not harm any non-target species.

It was definitely an experience to jump in the murky water, being cautious of other spearos around you but you can’t see them too well, you can only hear the shots underwater coming from different directions. All in all, it was a good day out – feeling like I had helped our native fish species a little by reducing some competition from their natural habitat.

Our stats at the end of the day were: