Changing wildlife: this is the first article in a series looking at how key species such as bees, insects and fish respond to environmental change, and what this means for the rest of the planet.
The seas are warming. Collectively the oceans have absorbed more than 80% of the energy retained by the Earth through recent climate change.
However, actual warming of the water has been very uneven, with some seas heating up much more quickly than others. Temperate rises have been most extreme where there are strong currents flowing from hot tropical regions towards the poles.
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And as warmer seas move further south, tropical wildlife is going with them, giving us a dramatic insight into how global warming is changing our oceans.
The East Australian current (the famous “EAC” used by migrating turtles in the movie Finding Nemo) brings warm water from off Queensland down the New South Wales coast to Tasmania. Similar currents also exist off southwestern Australia, Japan, the eastern United States, southeastern Africa and southern Brazil.
Many marine creatures have a wandering larval stage in their life cycle. These are often microscopic creatures that are transported by waves and currents far from their parents. Some larvae can travel for months or even years before settling down in suitable habitat and metamorphosing into the more recognisable crab, shell, sea-star or fish that we see along the coast.
This life history means that marine animals can respond rapidly to changing water temperatures and currents. Like Nemo they can be swept down the coast and survive in newly warming environments.
So let’s follow Nemo and find out what is happening along the eastern coast of Australia right now.