Fish monitoring stepped up in bid to stop invasive species

Nov 29, 2013 by Steven White
Fish monitoring stepped up in bid to stop invasive species
Tilapia were found predominantly in the permanent estuarine region which is a body of water approximately 2km in length, disconnected from the ocean for most of the year. Credit: Batavia Coast Maritime Institute

An invasive fish species currently occupying the Chapman River is being monitored in research exploring the effectiveness of different capture methods.

The Durack Institute of Technology's Batavia Coast Maritime Institute (BCMI) in Geraldton has just completed a Recfishwest sponsored preliminary survey on tilapia.

Tilapia (Oreochromis mossambicus) is an invasive fish native to Africa and is part of the cichlid family of fish of which there are more than100 variants.

"Tilapia are a massive pest worldwide and their presence in the Chapman River which is a fairly small discontinuous waterway lends itself to exploring methods of removal," BCMI's Colin Johnson says.

Dr Johnson oversaw the survey which was conducted by BCMI students and was the major project for diploma student Kirsten Surmon.

"[It was my job] to design and implement a complex field experiment as one of the core units of the diploma," she says.

Students sampled fish using seine nets, fyke nets and various types of boxtrap, line fishing, dip netting and visual surveys and examined data from previous surveys.

Sampling sites included all significant permanent water bodies within the Chapman River main channel but no tilapia have been found above the Utakarra gauging station 9kms upstream of the river mouth.

Tilapia were found predominantly in the permanent estuarine region which is a body of water approximately 2km in length, disconnected from the ocean for most of the year.

"If we do find them upstream of the estuary, particularly in some of the smaller waterholes, these are some discreet areas where it might be possible to conduct comparative trials for removal techniques as well as impact studies of tilapia presence," Dr Johnson says.

It is not clear how tilapia got into the Chapman River but it seems likely they were released as ornamental fish.

Fieldwork for this project ran from mid May until late October during which time they conducted 19 separate sampling expeditions with 3000 total hours of sampling time.

This study saw the beginning of a larger project under the Australian Government's Caring For Our Country program, to be jointly managed by BCMI and the Northern Agricultural Catchment Council.

"The project will run until 2017 and will survey the Irwin, Greenough and Murchison Rivers with focus on biodiversity, tilapia monitoring and developing tilapia control strategies in the region," Dr Johnson says.

He says if the has spread significantly into other local the focus will change from control through removal to preventing further spread.

Explore further: Can pollution help trees fight infection?

Related Stories

Study sheds new light on how some fish adapt to saltwater

Oct 08, 2013

(Phys.org) —Tilapia fish readily adapt to fresh or salty water, making them both good candidates for aquaculture and potential invasive pests. New work at the University of California, Davis, shows how tilapia can change ...

Tilapia feed on Fiji's native fish

Jan 12, 2010

The poster child for sustainable fish farming -- the tilapia -- is actually a problematic invasive species for the native fish of the islands of Fiji, according to a new study by the Wildlife Conservation ...

Piddling fish face off threat of competition

Dec 12, 2007

Research published today in the online open access journal, BMC Biology, shows that male tilapia fish use pheromones in their urine to fight off competitors and enforce social dominance.

Edible fish feasts beats malaria

Aug 09, 2007

The emerging threat of pesticide resistance means that biological malaria control methods are once again in vogue. New research published in the online open access journal BMC Public Health shows how Nile tilapia, a fish ...

Recommended for you

Can pollution help trees fight infection?

9 hours ago

Trees that can tolerate soil pollution are also better at defending themselves against pests and pathogens. "It looks like the very act of tolerating chemical pollution may give trees an advantage from biological ...

Stink bugs have strong taste for ripe fruit

11 hours ago

The brown marmorated stink bug has a bad reputation. And for good reason: every summer, this pest attacks crops and invades homes, causing both sizable economic losses and a messy, smelly nuisance—especially ...

Iceland whaling season underway despite protest

13 hours ago

Icelandic whaling boats have left port to begin the 2015 whaling season, authorities said on Monday as more than 700,000 people signed a petition calling for an end to the hunt.

Study suggests there are only two tiger subspecies

19 hours ago

(Phys.org)—A team of researchers with affiliations to institutions in Germany, Denmark and the U.K. has concluded after extensive research, that there are really only two subspecies of tigers, as opposed ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.