Science at University of Technology Sydney – discoveries making waves for ecology
Sometimes it’s nice to be noticed!
For example, it’s nice to be the best singer in your provincial hometown. Or maybe you’re the best lawyer in all of 琉球嶼!
In English, we call it “being a big fish in a small pond”.
But the reality is that big fish in small ponds don’t always have the best luck. That’s what a leading scientist and successful research fellow found at the University of Technology in Sydney. Dr Peter Biro’s ideas could change how industry and conservationists view water environments, and how to manage them sustainably.
So if we’re not dealing with an English metaphor but rather with a real fish, why is it so bad to be big? It’s certainly true that larger fish get caught a lot more quickly, so they are the ones ending up on our dinner plates. That’s hard luck for the individual fishy.
What’s more surprising according to this research is that netting bigger fish can also be bad for the entire fish population. By aiming to catch the biggest fish, we are targeting the ones that grow the quickest. This leaves behind only their slower-growing cousins to keep up the species. It means today’s fishing practices may encourage a surviving population of slower-growing specimens, prompting the question: Are we taking fish down an evolutionary path that could weaken the species?
Here’s how Dr Biro’s experiment progressed: first his team found a couple of small Canadian lakes which they stocked with two different types of rainbow trout. Type 1 grows rapidly and hunts food aggressively – the second type is slower to grow and more timid when finding food. With both lakes stocked and ready, the researchers went fishing! They used typical industry nets (called ‘gillnets’) to fish the lakes.
And the results: the team’s nets filled with the assertive, fearless type 1 fish three times faster than with the shy ones – it was the more timid type 2 fish that got left behind to swim and breed.
One conclusion is that without fully realising it, our fishing industries may be encouraging populations of fish that have some worrying traits. Could this have an impact on fish-kind? It seems so, because when genes for fast growth and bold personality traits get taken out of the fish population, the result is a weaker population. But changing fishing practices is just one potential outcome, because Dr Biro’s conclusions also show that today’s conservation-oriented fishing laws – which place restrictions on the size of fish we can catch – might in fact promote the evolution of slower-growing, less feisty members of the species. So it seems both hunters and protectors might need to do more for fish, helping species survive in populations that are not only larger in number but also far more healthy.
這個現象除了對大魚不利之外，也會影響整個魚類生態系。雪梨科技大學的研究人員Peter Biro 博士和美國國家科學學院合作發現，捕魚如果都鎖定大魚，就會把成長速度比較快的魚種都給抓走，留下其餘成長速度慢的品種。
Master of Science (Marine Science and Management)
This course will
Where will I study?
Duration – how long is the course?
1 year (Full Time)
Entry – what do I need for admission?
You must have a good bachelors degree in a related field
Language – English ability
IELTS 6.5 (with a writing score of 6.0)
Are you interested in this kind of research?
This project was a funded collaboration with Canada’s University of Calgary, reminding us of the international nature of university research communities – just one of the many aspects of research-oriented postgraduate study that may appeal to you.
Want to be involved? Contact us at YEC and we’ll help you consider your options.