WHEN the director of PNG Forest Research Institute Prof Simon Saulei commented on how the tuna stocks will decline because of climate change impact, I am not surprised at all.
As academics, we make comments all the time usually based on current schools of thoughts, models-based prediction or from research results by fellow scientists.
I, for one, can make similar comments on climate change impact on PNG’s tropical forest.
One could predict that as temperature climbs, tree species that currently thrive at colder climate will disappear by 2050 because they cannot survive in warmer temperatures.
Further, trees that thrive at sea level will tend to invade the warmer higher elevation area, just like what the mosquitoes are doing right now, moving from lowland areas to the highlands.
This means we could one day see tropical forest trees replacing montane trees at Mt Wilhelm.
This prediction is based on common knowledge that you can access from the internet at a hit of a button.
I am an animal physiologist.
However, I can still say something about the forest in light of climate change because we are bombarded with information everyday.
Going back to tuna stock, as far as I know, there are no experiments done to test climate change impact on tuna.
All we know is tropical dwelling fish are now being seen and caught in temperate zones because of warmer sea waters which is expanding their habitat, thanks to climate change.
On the other hand, we are yet to see major exodus of tropical fish including tuna.
So far, we can say that exotic fish are turning up at temperate zones whilst we see no depletion of tropical fish due to climate change as yet.
As intelligent creatures, we can predict:
* Tuna fish will move towards the poles – northward and southward migration due to warmer central south Pacific Ocean;
* Water surface temperature will not change despite higher surface temperature because of mixing of cold water bodies by oceanic circulation; and
* Fish will adapt to higher temperatures and their current habitat will be unaffected by temperature change. This is how academics see the natural world.
Dr Ralph Mana