Currents change?


O. bimaculoides
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:


There are several schools of thought on this...pessimistically, one could say that such species would be obliterated by the change in current(s) 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.



O. bimaculoides
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.


O. bimaculoides

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....


O. bimaculoides
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 :)


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. 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.


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:
Matt Jones said:
... 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:
I haven't read the book, but I have heard other "experts" talk about how "global warming" has been blown WAY out of proportion. As I said in my last post, I'm not a climatologist but there are some very noticible changes happening in the arctic.

In my humble opinion, there is a warming trend going on that may be influenced (ie. sped up) by human activity. There are too many signs showing this new higher temperature for us to rule it out totally. Especialy here in the sub-arctic/arctic regions.

I don't have time at the moment to do a websearch to back up my claims of "signs", but when I do get the chance I will try and find some of the newest information regarding changes in the Arctic.


interesting thread. You know, i just read this great book come to think of it...

called a Short History of Nearly Every Thing, written by Bill Bryson.

it's exactly what it sounds like and definately written for the layperson, but even dorks such as us will find it interesing AND entertaining. Some of the contents you're likely to know already, but there's plenty you might not. I believe he does touch quite a bit on climate change... as well as just about everything else.

I breezed through the 500-some-odd pages in about 4 days (woot for spring break last week!)


In my humble non-expert opinion... climate change.... well it just happens. We very likely might be speeding it up, but the earth has been swinging between different periods since before we were first chipping out tools and warming our hands by fires.

How about that Little Ice Age? There was a time people worried about global cooling. The Earth is just such a complex system that everytime we think we see a trend, i wonder if it might turn around and start heading the other direction on us.

We haven't had the capability long enough to monitor trends over an expansive enough amount of time.


Staff member
Whew!! The first couple of posts made it look like this was going to happen tomorrow, we still have a few weeks don't we :wink:

Over the past few hundred million years oceans and seas have come and gone, currents have changed, climates have gone from cold to hot and back. Maybe someday we will be able to stop the continents from drifting, the currents from shifting, the mountains from eroding to the sea, super-volcanos from cooling the world down, or even stop greenhouse gases from warming it up. In the meantime, I think we should at least try to minimize our impact.


O. bimaculoides
Continued next week in.... DOOM DOOM DOOM I SAY!!!!

Well I am one of the converted. I try to hang with smart crew so I can use osmosis to steal their brains...... and well as I see it, the evidence is there if you choose to look.
Around here we are getting more and more tropical fish that get swept down by the currents (seen Nemo.... yes thats the current) and then freeze to death when they hit the southern waters. I don't have much real evidence to back this up but the trawler skips I'm befriending to get octopus off have been commenting on several new fish that normally don't come this far south.
These guys are prawn trawlers too...... before someone crucifies me for not sinking their boat as I left. 8-)

Anyway believe it or not. Things are gonna change BIG time in the next 50 years. By the time we realise how screwed we really are it's gonna be too late. That co2 inertia mentioned above is crazy. Basically we could stop everything industrial and it's still gonna keep getting worse for quite a while. Btw there is zero chance of us stopping and most predictions can only forcast increases.

If only the human race could be trusted with nuclear power..... if it could (and it can't) then that would be the go... the sorta stop gap while we develope all these other friendly solar/wind/tide etc technologys. But no.... instead some nations are trying to stop others from building nuclear reactors (probably rightly so too :sad: ) and we are fighting over the last of the dirty fuel.

Tipping point is something that terrafies me personally. We know so very very little, but I myself think we know enough to be bloody scared and make a few BIG calls now so our kids kids can see something that resembles the kick ass planet we have now. This change HAS started, yes it's slow now but it's only gonna get faster and faster and faster.....

Sorry if that in anyway made me look like a troll, was not the objective I assure ya!

Anyway if the water from the deep stops coming to the surface won't the monsters from the deep have to come up instead? :confused:
Now that could be kinda groovy to see...

Steve O'Shea

Colossal Squid
Sorry, prawn trawling is one of the most environmentally destructive of all fishing practices (usually using bottom trawls with light-weight, small bobbins or pieces of rubber on the ground rope). It is responsible for most damage done to the seabed between 250-550m in New Zealand; terrible damage is and has been done elsewhere (for almost a century).

I can't remember the true stats offhand (and these will vary from region to region), but you can expect ~90% of the total catch to be bycatch (including your octopuses). It is responsible for the extinction of one species of cirrate octopus, and near-extinction of an incirrate species in New Zealand, and a wealth of other molluscan, echinoderm and coelenterate species.
H. lunulata said:
IT is all in Gods hands i mean itis whatever he has planned for us
Hi there,

I'm sorry but I have to make a comment about this statement.

First off let me say that this is not going to be a personal attack on you, but I have heard this statement from many people when discussing many topics. Your post just set me off.

In my opinion, comments such as these are very dangerous as they are a form of "cop-out"
Saying that something is pre-ordained by a higher power is a way to "relieve" us of the burden of guilt and thereby the burden of fixing the problem.

In my opinion we are the masters of our own fate and we are doing the damage. Therefore we are resposible for whatever outcome is generated by said damage.

I understand and honour the need for religious belief and expression, but because this a public board I felt a need to counter this statement with another view on "our" worlds situation.

Even if there is a "plan" built and conducted by a higher power, we should not go along our merry way destroying the world around us and blaming a "God" by saying it is their "plan".

Please, I'm not trying to turn this thread into a religious discussion and please do not take this personaly. If you wish to begin a debate on the topic of religion and the sciences, I beleive it would be better done in PMs as this is not a forum for such topics.

If you wish to debate, I look forward to hearing from you. :smile:



Right on. I'm glad that you responded to that first, since my response would've been less even-tempered. It's a [darned] [silly] [thing] for [people] to say.

H. lunulata

O. bimaculoides
I too believe for people to help the earth and all its inhabitants but i was just saying that whatever is in Gods plan is in his plan so if it was going to happen it will happen but we still should try to help the earth beacause God wants us to be helpful to each other and our enviroment now that we have completely blew the term ON TOPIC out of the water i just want to say i do not want to get into a debate into anything(even though i am a lawyer) can we please talk cephs because i dont feel like offending anyone else as i seem to have

Members online

No members online now.