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vaguely oceanic stuff
I've been having more fun with the Open University course
As this is a bottom-level course it's intended to be very accessible. The work is hard in many places, but there's a deliberate effort to avoid too much chemistry and math. The math in the course assessment was some of the easiest marks I've ever gained. It's a calculation of productivity in food chains, but once you get past the intimidating language, all it actually involves is multiptlying two strings of numbers together and adding up the results.
There's so much in the oceans that we don't really know and so much that is amazingly complex.
Fish migrate to lay eggs in one area so that currents will carry them to safe nursery areas for the young fish which will then move again to more open seas when they are older.
Zooplankton (very tiny floating animals) travel up and down every day. They go up at night and down in the day. Often by a several hundred metres. They probably do this to avoid predators in the day, but there are other possible reasons as well. The effect is so marked that the layers of plankton produce strong echoes and led to several areas being mistakenly marked as having shallow reefs on navigation charts.
POlar bears are excellent swimmers, so good that they can swim a hundred miles across open sea.
Food chains are longer and more complex (the correct statement is that there are more trophic levels, but I'm not up to explaining trophic levels in one sentence) where nutrients are scarce. This is almost counter-intuitive, but it made sense when I started to think about it. It probably relates to available food in a given area and what size territory a predator needs and what size predator it is capable of supporting.
If you have a really high density of plankton, then you can support baleen whales. Where plankton are fewer, you have intemediary steps in the food chain.
I hope that makes sense. I find it fascinating.
As this is a bottom-level course it's intended to be very accessible. The work is hard in many places, but there's a deliberate effort to avoid too much chemistry and math. The math in the course assessment was some of the easiest marks I've ever gained. It's a calculation of productivity in food chains, but once you get past the intimidating language, all it actually involves is multiptlying two strings of numbers together and adding up the results.
There's so much in the oceans that we don't really know and so much that is amazingly complex.
Fish migrate to lay eggs in one area so that currents will carry them to safe nursery areas for the young fish which will then move again to more open seas when they are older.
Zooplankton (very tiny floating animals) travel up and down every day. They go up at night and down in the day. Often by a several hundred metres. They probably do this to avoid predators in the day, but there are other possible reasons as well. The effect is so marked that the layers of plankton produce strong echoes and led to several areas being mistakenly marked as having shallow reefs on navigation charts.
POlar bears are excellent swimmers, so good that they can swim a hundred miles across open sea.
Food chains are longer and more complex (the correct statement is that there are more trophic levels, but I'm not up to explaining trophic levels in one sentence) where nutrients are scarce. This is almost counter-intuitive, but it made sense when I started to think about it. It probably relates to available food in a given area and what size territory a predator needs and what size predator it is capable of supporting.
If you have a really high density of plankton, then you can support baleen whales. Where plankton are fewer, you have intemediary steps in the food chain.
I hope that makes sense. I find it fascinating.
no subject
Bathyscaphes supplied with the course materials then? ;-)
Does the course cover hydrothermal vents and black smokers? The life around them is amazing. 8-)
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no subject
Free copy of the 'Blue Planet' videos with every course. The photography is so amazingly fantastic.