Aquaculture I

QUESTION: A few years ago I read that aquaculture was the answer to the problems associated with commercial fishing, but lately I have been hearing differently. What has happened? Sinjan from Johannesburg.

ANSWER: Sinjan, when it comes to modern food production, there are no magic bullets. It could be said that when mankind was roaming about gathering nuts and berries and killing the occasional antelope that we were truly living in an organic, sustainable manner. But quite frankly, it was probably no panacea. If the hunt was unsuccessful the tribe could starve. Without ownership, resources went to the strongest group, which in a clinical sense might be good for evolution – survival of the fittest – but to those who were driven into less fertile regions it meant a grim existence, and perhaps a slow violent demise.

As stationary agricultural and domesticated animal-based civilizations formed, and rules of ownership began to be developed, mankind was able to be fruitful and multiply, so to speak. And with the removal of fear and wandering, time was made available to improve systems. But immediately this began to affect the environment. Burning was used to clear land. Water sources were diverted and things like fertilizer application began to be used to increase returns. Stationary stock animals produced waste that after a good rain ended up in the same creek where people bathed and drank. Things have never been the same.

Aquacultural seafood production in many ways is just now entering this stage, which is quite amazing really considering we are now mapping DNA and peering into the reaches and beginnings of the universe. So it is a work in progress. But unlike those early tribes we now can implement systems with science as our guide. But aquacultural development, being based around the aquatic realm, faces philosophical and political questions as much as empirical. We are still squabbling over who owns what waters; and issues referred to in theories such as the tragedy of the commons, issues that for land-based food production have pretty much been solved, are still tangent to aquacultural development.

But aside from philosophical meanderings there are a few facts guiding us. First and foremost we are harvesting pretty much all we can from the seas, and actually in many cases too much. No matter what else happens we can’t dramatically up the volume of catches. Aquacultural development will continue. Secondly, aquaculture does give us a great degree of hands-on control. We can tinker with feeds and enclosures, the amounts of light fish receive, the water temperature and a lot more. This is not quite as possible in the wild. And as with modern agriculture, there is a greater level of certainty about harvests and investments (though nothing is 100%). So it seems aquaculture is the answer to the needs of the hungry masses seeking that great source of Omega 3’s we talk about all the time.

But what of the challenges? Where’s the down side? And why keep fishing in the wild at all? As Goldblum’s character in Jurassic Park says, “Nature finds a way”. It resists control. Fish who should be quite happy swimming in the safe confines of a netted enclosure, feeding on tasty easy-to-find morsels, have the damnedest tendency to plot escape. As stocks are confined, disease and parasites are able to become firmly established and transmitted easily, even perhaps to wild fish swimming by. These fish must be fed and many are carnivorous, which puts pressures on wild industrial fish stocks. Too the facilities are in many cases placed in the natural environments.

We will over the next few weeks be addressing particular concerns, starting next week with the feeding of aquacultural species. In particular we will look at the use of wild stocks in feed production for farmed carnivorous fish species. We will also reference the use of fishmeals and fish oils in the production of feed for land based animals, as the two topics are intricately linked. A lot has happened in these areas and exciting developments are occurring very rapidly so please pop back in and read next week’s Ask Deep Blue.

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