June 27th 2006
Life in the Deep Ocean
When Hollywood gets to work making the next scary space monster movie chances are they will be drawing their inspiration from somewhere a lot closer to home. A kind of space few of us even think about, let alone know much about, and yet it is immensely vast, mysterious and totally absorbing - especially when you are introduced to it by a gifted communicator. It is life in the deep ocean and, next week, a man who is passionate about this world, with an immense knowledge of it, Dr Don Kinsey, will be holding a public talk at the Arcadia RSL, Monday, 10 July, 10:00 to 12:00 with a tea/coffee/chat break. This also will be the introduction to his recommenced U3A program (see under What's On).
Most of us probably think we are a little familiar with what goes on at the surface of the open ocean - but are we really? We tend not even to notice the plants that drive the system and which are nearly all microscopic. The most dominant fish are not the familiar tuna and flying fish but actually mysterious vertical migrators that come up from the depths to feed under cover of darkness. Then there are those creatures that live their whole lives in the great depths. There are no plants here and all the support systems come ultimately from the surface. One particularly macabre strategy is to produce a lot of eggs that float to the surface, hatch, and produce babies that feed well in that enriched environment. These well fed children, then move down to the ocean depths, hopeful of a long adult life. Unfortunately mum, dad and friends are all waiting for this feast from above and few survive.
But there are exceptions. The ultimate in weird is the totally independent ecological system that has evolved and thrives in the highly toxic environment at the volcanic zones where the earth's new tectonic plates are being formed. These life forms are totally independent of the surface ocean. The basic foodstuff is bacteria which are utilising the very poisonous hydrogen sulphide gas from the volcanic vents. There are 2 m long worms, 30 cm shellfish, and highly specialised blind crabs and fish. No normal ocean creatures could survive here.
In yet another extraordinary example of independent evolution, there are ecosystems consisting of worms, mussels and shrimps living on bacteria that are thriving on methane gas from ancient seeps in the ocean floor.
All this and more will be covered in Don's talk.
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