Fish-watching

Juvenile Tandan, Kedron Brook.

As a naturalist, I aim to be well-rounded in my wildlife observations, but there's one group of animals I've always struggled to spend time with: fish. While I have no issue with recreational fishing if done responsibly, I personally don't wish to cause unnecessary stress to any creature I encounter, so that rules out the obvious choice of 'hook, line and sinker' for fish interaction. Yesterday morning, while sitting by the banks of the Cabbage Tree Creek in the north Brisbane suburb of McDowall, I thought about some of the other ways I have been able to observe fish.
 

Fish-watching equipment on the banks of the Cabbage Tree Creek, McDowall.

Netting

Male Mosquitofish, Cabbage Tree Creek.

Scooping a dip-net into a creek can sometimes produce interesting results. My most successful occasion with this technique occurred at Kedron Brook, when a swift jab into some submerged plants produced a juvenile Tandan (Tandanus tandanus). In the upper reaches of Cabbage Tree Creek yesterday, I only caught Mosquitofish (Gambusia holbrooki), an exotic pest species which was unfortunately plentiful. It is helpful to have a container filled with creek water ready to deposit the fish into; keep in mind that the law forbids you from keeping or re-releasing any exotic fish you have captured.

Trapping

After watching this video in 2013, I was sure that a fish-trap would be the best way for me to witness native fish up close. Apart from the occasional native gudgeon however, I've actually found this method to be the least successful way to obtain and observe fish. The only way I've deviated from the technique shown in the video is that my trap is bright blue, not the camouflaged brown that is recommended. There are a couple of important things to remember when using a fish trap. Number one is that you should never leave the trap in the water for more than half an hour, and it is best to keep an eye on the trap during this time. This is so that air-breathing aquatic animals such as turtles and platypus do not accidentally make their way into the trap and drown. Secondly, fish traps can only be used in freshwater environments and must bear the name and address of the user.

Filming

Many fish species have an innate sense of curiousity about their surrounds that anyone with an underwater camera can make use of. I have often simply placed my bright blue Canon D20 into the shallow margins of a water body (both fresh and salt) and then stood back as a variety of fish swam up to investigate. Analysing the video later will reveal the species present; in the case of the video above, Western Carp Gudgeons (Hypseleotris klunzingeri) and Barred Grunters (Amniataba percoides) are shown near the shoreline of Lake Somerset. Unfortunately, the steep banks and deep pools of Cabbage Tree Creek do not suit this method of observation.

Male Swordtail; Photo by the Department of Fisheries,
Western Australia.

Sit Down and Watch!

My favourite way to watch fish is also the simplest - sit down somewhere with a good view and stare into the depths below! This was the most productive method of observation by Cabbage Tree Creek yesterday, allowing me to study schools of exotic Swordtails (Xiphophorus helleri) and - more excitingly - a large Tandan. Also known as the Eel-tailed Catfish, this latter species is not the kind of fish you want a tactile encounter with, as they are armed with venomous spines. Elsewhere, I have waited patiently on creek banks to watch Long-finned Eels (Anguilla reinhardtii) and Tilapia (Oreochromis mossambica) in Coorparoo, and Sea Mullet (Mugil cephalus) and Crimson-spotted Rainbowfish (Melanotaenia duboulayi) in the Redlands. Sitting quietly near a waterbody is useful for other reasons also; not only do other bush creatures such as water dragons and butterflies suddenly appear all around you, it will do wonders for your peace of mind as well.

Fish-watching: get into it!