Warmer oceans will make some fish bigger

A huge school of fish at Darwin Arch, Galapapagos

A huge school of fish at Darwin Arch, Galapapagos

Warming of oceans will make some fish balloon in size, study finds

Scientists probing the effects of climate change have now discovered that for every one degree change, sizes could fluctuate by up to 40%. While most species will get smaller, 45% will get bigger.

One of the reasons this study is important is that it shows the complexity of species’ responses to warming in our oceans. Much of our understanding of the temperature-size relationship comes from the laboratory. Taking our predictions to the wild shows us there is a lot we still need to learn about this hugely important phenomenon

Nicholas Payne, assistant professor in zoology in Trinity College Dublin’s School of Natural Sciences, co-author of the study

A team of scientists used 10 million visual survey records of 335 fish species across coastal locations in Australia, which spanned decades.

A school of Jack fish loom over a diver who is looking up and photographing them
A school of Jack fish | Image: Octavio Aburto

The scientists confirmed that changes in water temperature drove changes in fish size. Before now experts claimed fish sizes would reduce as temperature increased.

Fish size changed between 4% and 40% per one degree change in temperature. Ocean temperatures are set to rise between 1.2 and 3.2 degrees by 2100. This suggests the impact on fish size will be very significant. It will have serious implications for fisheries.

The crucial message is that warming seas will have unanticipated impacts on the entire ocean food chain, which could threaten marine conservation initiatives.

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What can I do about global warming?

Speak up! By voicing your concerns—via social media or, better yet, directly to your elected officials—you send a message that you care about the warming world. Encourage your MP to enact new laws that limit carbon emissions and require polluters to pay for the emissions they produce.

Power your home with renewable energy.
Choose a utility company that generates power from wind or solar. If that isn’t possible for you, take a look at your electric bill; many utilities now list other ways to support renewable sources on their monthly statements and websites.

Building heating and cooling are among the biggest uses of energy. You can make your space more energy efficient by sealing drafts and ensuring it’s adequately insulated.

Invest in energy-efficient appliances.
Energy efficiency is the lowest-cost way to reduce emissions. When shopping for refrigerators, washing machines, and other appliances, look for the Energy Efficiency rating.

Reduce water waste.
Saving water reduces carbon pollution, too. That’s because it takes a lot of energy to pump, heat, and treat your water. So take shorter showers, turn off the tap while brushing your teeth.

Actually eat the food you buy—and make less of it meat.
If you’re wasting less food, you’re likely cutting down on energy consumption. And since livestock products are among the most resource-intensive to produce, eating meat-free meals can make a big difference, too.

Buy better bulbs.
LEDs use up to 80 percent less energy than conventional incandescent bulbs. They’re also cheaper in the long run.

Pull the plug(s).
Audio and video devices, cordless vacuums and power tools, and other electronics use energy even when they’re not charging. Don’t leave fully charged devices plugged into your home’s outlets, unplug rarely used devices or plug them into power strips and timers, and adjust your computers and monitors to automatically power down to the lowest power mode when not in use.

Drive a fuel-efficient vehicle.
Smart cars, such as hybrids and fully electric vehicles, save fuel and money. Before you buy a new set of wheels, compare fuel-economy performance.

Maintain your ride.
A simple tune-up can boost miles per gallon anywhere from 4 percent to 40 percent, and a new air filter can get you a 10 percent boost.

Rethink planes, trains, and automobiles.
Choosing to live in walkable smart-growth cities and towns with quality public transportation leads to less driving, less money spent on fuel, and less pollution in the air. Less frequent flying can make a big difference, too.

Shrink your carbon profile.
You can offset the carbon you produce by purchasing carbon offsets, which represent clean power that you can add to the nation’s energy grid in place of power from fossil fuels. But not all carbon offset companies are alike. Do your homework to find the best supplier.


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