I remember being advised in the 1950's to look out for livestock because of toxic algae blooms in the Darling River south of Bourke.

Those were days when Australia was self sufficient in fresh fish from the ocean, not so these days. Now Australia imports 70% of it's fish including to feed aquaculture.

I think the actual subject of world food security has come into being because governments are now quietly aware under the table, that world ocean fish stocks are seriously and generally depleted. Independent evidence however indicates they are devastated.

Many farmed animals need fishmeal or similar affordable and viable protein supplement, especially during winter such as in Europe.

I am amazed ocean food sustainability collapse is not being discussed generally concerning food security.

I agree, JFAus, that we ought to be talking more about food security both on land and in the sea. I heard, and I wish I could remember where, that the whole problem of Somali pirates brgan when honest Somali fishermen could no longer make a living from fishing off their coast. Supersized trawlers had vacuumed up all the fish the fishermen had depended on for their livelihood.
Global climate zones are moving poleward and we need to make sure that we can grow what we need with the changed water supplies and the new weather that farmers are already experiencing.

Food security now that every climate prediction and increasing ocean acidity prediction by the IPCC has been wrong or exaggerated, is the new scare tactic.

AR5 has a specific dire prediction about the MDB and its agricultural prospects.

It is culpably wrong as Ken Stewart's thorough analysis shows:

http://kenskingdom.wordpress.com/2014/04/04/ipcc-dud-rainfall-predictions-for-the-murray-darling-basin/

This is the thing; the IPCC is overseeing an attempted revolution in humanity values from how we live, to how we grow our food, our energy production and use and how we should react to 'nature' and indeed how we view existence and its limitations.

This revolution is predicated on scientific evidence which is consistently wrong, inadequate and demonstrably tainted with ideology of a quite loathsome misanthropic type.

And still we have sanctimonious fools flinging vitriol at sceptics. And complaining when they get a taste of their own medicine.

Too bad.

Brian of Buderim, I understand Somali fishermen had to contend with fishing boats including from western Pacific waters. The super size you mention is new to me but the vessels involved would have been super sized to Somali people. The fish link to that sorry situation in Somalia is I think kept under the carpet by news media that for whatever their reason is keeping the devastated state of world fish stocks under wraps. Yet it is inevitable it become known in order to understand essential solutions. Aquaculture is not the answer because that product can not be afforded by the majority in need.

I think Buderim ginger has also taken a hit due to lack of rain. Look, I consider weather and climate is changing due to human impact but the cause is not increase in CO2 according to evidence I am seeing. I think the problem is solar warmth held back in unprecedented sewage nutrient fed algae plant matter in ocean and sea and big lake waters. The Great Lakes for example, and that warmth is held back for 4 or 5 hours into the night.
There is more on that at another OLO thread, later pages at:
http://forum.onlineopinion.com.au/thread.asp?article=16169&page=

cohenite, I think some sceptics can be as hard minded as warmers.

I find myself in the middle here, between sceptics and warmers, dealing with reality presently not yet on sceptic or warmer radar.

I think a lot of the IPCC false alarms may be due to more localised weather change events, not global at the same time.
The whole atmosphere of the planet is not warming at the same time, because increased warmth I am seeing is coming from some very huge patches of warm water where algae is more dense than usual.

I think that categorically increased density of ocean algae matter has not been measured and assessed and included in AGW computer modelling. The GW seems wrong I think because of the localisation of the warming events.

Perhaps you can get an idea of how weather change can begin in a local area, for example the Pacific equatorial area, by considering availability of nutrients for algae influencing the El Nino algae phenomena. And I advise there is no mention of nutrients from east Pacific coast waters, prawn farms sewers and all. No nutrient pollution. No excess in algae. No increase in mass retaining whatever slight degree of increase in warmth unnaturally for a few hours.
Only upwelling nutrient supply is stated, we assume that supply is natural. See:
http://earthobservatory.nasa.gov/Features/ElNinoColor/el_nino_color_3.php

JF, my understanding is that algae can only produce energy from sunlight whereas cyanobacteria can produce energy from both sunlight and such nutrients as you talk about.

The level of cyanobacteria is therefore a better marker of the 'pollution' from agriculture runoff and other human activity which is often declared to be a serious pollutant affecting such things as the GBR.

Whether cyanobacteria is declining or not is problematic with Boyce et al initially claiming it is but subsequently retracting that conclusion:

http://wattsupwiththat.com/2011/04/25/the-ocean-wins-again/#more-38673

Science is rarely settled except when it comes to AGW.