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Currents change?

Mar 2, 2005
OK so this may be a bit OT but I have been thinking about it all day and it's bugging me.
So if the ocean reaches tipping point and the currents all go to hell......
WHAT on earth happens to all the planktonic reef fish babys?
I mean they won't end up on the same reefs..... so does that mean new species for areas or that after a few generations they are just merely lost to us?

I have heard the excuse that it doesn't matter about collecting most adult reef fish because 95% are always floating around as planktonic fry but where will they float in the future?

All a bit outta my league and maybe the oceans will be so stuffed by the time the currents change enough for it to effect anything but ummmm..... :shock: :confused:


TONMO Supporter
Mar 15, 2003
There are several schools of thought on this...pessimistically, one could say that such species would be obliterated by the change in current(s)...my bend is that it would force rapid change in species, adaptions would have to take place very fast, but it is possible...
Many, many layers to this problem...unfortunately, there is no way to say for sure what will happen. Some extinctions seem likely, hopefully it will not be massive.

Feb 22, 2005
This is definately not a simple answer. We do not know enough about marine species and even reef fish (which are heavily studied) to even start to predict the outcome to this one. It may be survival of the fittest or those that can adapt fast enough. There may be no effect at all. As far as I am aware they are still looking at how planktonic larval forms make it back to the reef. I remember reading a suggestion that the plankton use chemical cues and exploit the currents and vertical migration to get back to the reef. It was suggested that plankton was not as helpless in the ocean as once thought. I will try and find a refernence for you.
Mar 2, 2005

Thanks for that!
Not really being that clued in on the whole ocean thing really it just sorta struck me as a... but if that happens what happens to the little fish? uh... you know simple sorta thought progression.
Smart people rock. Help me sleep at night anyway. :smile:

Would be nice to know that they won't be too effected. Gets a bit gloomy when you don't know the whole story and it all just seems like a fishtank going way bad.... what with too much co2 injection forming carbolic acid and eating away at the chunks of coral you use to buffer the thing... and the heaters stuck on and we are helpless to cool the tank down and the sumps rising and gonna overflow water all over the carpet.....


Myself I like to think that the whole thing is gonna be a massive water change. Only instead of lowering nitrates it's gonna lower humans. Hopefully a bit of civilisation survives (the good bits) with the few humans and our species goes on. Even if it doesn't though. Something will take our place. Life is never as easily crushed as people think.

But to sorta go back where I was.... if the baby reef fish that have a planktonic stage don't make it back to the same reef it could be a good thing for the cardinal fish and stuff! All hail the mouthbrooders I say, for they shall inherit the reefs.

How do the cleaner fish breed? Cause losing them always seems to kick a reef in the guts while it's down from what i have read....
Feb 22, 2005
I can't find one specific reference that can help answer the question but there has been a lot of work done on larval recruitment on coral reefs by Dr. David Bellwood. If you go to Google Scholar and type in his name, all sorts of stuff comes up. Glad to hear you are sleeping better :smile:


Jan 15, 2005
Hi there,

From what I have read and heard from colleagues, it has to do with the amount of meltwater entering our oceans due to "global warming"

Here are a couple of articles that I found when doing a quick search on fresh water and ocean currents. They seem to give a decent overview of the theories regarding the currents slowing.


Living in the sub-arctic boreal forest region of Canada has given me a first hand view of the warming effects on the environment. One of the concerns is the loss of the permafrost which can lead to sediment erosion and/or eventual botanical change.

I'm an Archaeologist, not a climatologist, so I wouldn't even try to pretend to know everything that is happening up here, but there are some very obvious changes going on.

One benefit in an Archaelogical sense is being able to discover some very very interesting sites that wouldn't have been uncovered if it wasn't for the change in temperatures.

http://www.msu.edu/~oberg/articles/Yukon/glacier atlatl.html

Anyway, sorry for the quick diversion and "plug" for another science. :smile:

Interesting theories regarding the current changes, but I can't see anyway in which we can stop the change now. Too much thermal enertia.
Jun 3, 2004
I'm wondering, has anyone read Michael Crichton's 'State of fear'? It's a weird novel as he references his points and has a bibliography at the end. Basically his arguement is that there is no actual scientific evidence for global warming.

I haven't checked the refs as I'm dong this whole PhD thing...

I just thought the novel was very thought provoking, as I get the feeling that 'global warming' is just assumed to be happening by many people.

Matt :smile:

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