<![CDATA[Grist - Comment Feed for Umbra advises on tuna and mercury]]> Grist Comment Feed en Comment #1 by sindark http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Mon, 06 Apr 2009 12:32:51 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/1 One other thing to be aware of is how 'dolphin safe' tuna is arguably far less sustainable than the conventional sort.

One of the most reliable ways of locating tuna stocks is by following dolphins. Once you find dolphins feeding on the fish, you set your nets around and catch them. Of course, this method will sometimes lead to you catching dolphins as well. In eighteen years of dolphin set tuna fishing in the United States, 18 dolphins were recorded as caught, along with 34 tonnes of sharks and rays and 295 tons of other fish. Such by-catch is virtually always discarded. In an equivalent period of dolphin safe fishing (where electronic Fish Aggregation Devices are used instead), no dolphins were caught, but 237 tonnes of sharks and rays were, along with 15,500 tonnes of other fish. Again, this was discarded.

Dolphin safe fishing is also disproportionately likely to catch immature tuna, which have not yet reached their full size and which have contributed very little to reproducing the species, since tuna generally take a long time to reach sexual maturity.

This only makes sense if you strongly privilege dolphins over other forms of marine life.







]]> One other thing to be aware of is how 'dolphin safe' tuna is arguably far less sustainable than the conventional sort.

One of the most reliable ways of locating tuna stocks is by following dolphins. Once you find dolphins feeding on the fish, you set your nets around and catch them. Of course, this method will sometimes lead to you catching dolphins as well. In eighteen years of dolphin set tuna fishing in the United States, 18 dolphins were recorded as caught, along with 34 tonnes of sharks and rays and 295 tons of other fish. Such by-catch is virtually always discarded. In an equivalent period of dolphin safe fishing (where electronic Fish Aggregation Devices are used instead), no dolphins were caught, but 237 tonnes of sharks and rays were, along with 15,500 tonnes of other fish. Again, this was discarded.

Dolphin safe fishing is also disproportionately likely to catch immature tuna, which have not yet reached their full size and which have contributed very little to reproducing the species, since tuna generally take a long time to reach sexual maturity.

This only makes sense if you strongly privilege dolphins over other forms of marine life.







]]> Comment #2 by sindark http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Mon, 06 Apr 2009 12:33:32 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/2 According to this Economist article: “Tangled nets.” Oct 2nd 2003

“Mario Aguilar, of Mexico’s National Commission of Fisheries, stresses that chasing dolphins is the greenest way to fish tuna. Greenpeace agrees, as does the World Wildlife Fund.”

]]> According to this Economist article: “Tangled nets.” Oct 2nd 2003

“Mario Aguilar, of Mexico’s National Commission of Fisheries, stresses that chasing dolphins is the greenest way to fish tuna. Greenpeace agrees, as does the World Wildlife Fund.”

]]> Comment #3 by billyrainbow http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Mon, 06 Apr 2009 13:16:09 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/3 Umbra,

if you are going to offer "hard," "tough love" kind of advice like "don't eat tuna," don't you think the best idea is to go straight to the heart of the matter instead of offering what may as well be a band-aid for a sucking chest wound?

It's not that we eat tuna, it's that there's too many people doing the eating. Even pollution remediation ideas are in many cases disingenuous if not outright deceitful, because the environment can process a certain level of most types of pollution just fine. Not that it should have to; eliminating pollution is a crucial goal for a number of reasons. However, like resource conservation, it is important to realize that the most key aspect of the problem in many cases is simply the scale, which is in turn a function of the number of people involved.


We can learn to control population now, or have it forced on us in the typical ways - war, famine, disease, and as already mentioned, resource depletion and pollution.

None of the above is new information. We have known these things for quite some time, in some cases written material on the problems dates back to the ancient Greeks, Romans, and Chinese.

In some sense, it's almost a crime to make a prarmount virtue out of conservation when it's done without the primary focus being on conservation of our own numbers. The more we pare down our individual environmental footprints and the more we compromise our lifestyles to make room for more people, the more we hasten the inevitable catastrophe - perhaps even on the scale of an "Armageddon" - when there are no longer any conservation options available because there just isn't anything left to conserve, the vast numbers of humans needing whatever it is for their survival having already claimed it all.

Conservation really is good policy, as is not just reducing but actually eliminationg all pollution. Even in a purely unemotional world of simple mathematics efficiency demands conservation in a realtively closed system, and even were the system not closed, excuses to grant exceptions are subject to high standards when having something immediately is more important than doing it right.

i know that talking about population control opens a whole can of worms (which ought to be conserved, poor things), and there have been way too many really ugly things come out of that kind of discussion, like eugnecs and genocide, for example. And there's always the issues of who gets to decide who can have how many children, and what the criteria are for making the decisions. But we have got to provide those answers, and soon, or the fate of the world's tuna and polar bears either moot or among the least of all our species' worries.

Have a nice day,
billy rainbow



]]> Umbra,

if you are going to offer "hard," "tough love" kind of advice like "don't eat tuna," don't you think the best idea is to go straight to the heart of the matter instead of offering what may as well be a band-aid for a sucking chest wound?

It's not that we eat tuna, it's that there's too many people doing the eating. Even pollution remediation ideas are in many cases disingenuous if not outright deceitful, because the environment can process a certain level of most types of pollution just fine. Not that it should have to; eliminating pollution is a crucial goal for a number of reasons. However, like resource conservation, it is important to realize that the most key aspect of the problem in many cases is simply the scale, which is in turn a function of the number of people involved.


We can learn to control population now, or have it forced on us in the typical ways - war, famine, disease, and as already mentioned, resource depletion and pollution.

None of the above is new information. We have known these things for quite some time, in some cases written material on the problems dates back to the ancient Greeks, Romans, and Chinese.

In some sense, it's almost a crime to make a prarmount virtue out of conservation when it's done without the primary focus being on conservation of our own numbers. The more we pare down our individual environmental footprints and the more we compromise our lifestyles to make room for more people, the more we hasten the inevitable catastrophe - perhaps even on the scale of an "Armageddon" - when there are no longer any conservation options available because there just isn't anything left to conserve, the vast numbers of humans needing whatever it is for their survival having already claimed it all.

Conservation really is good policy, as is not just reducing but actually eliminationg all pollution. Even in a purely unemotional world of simple mathematics efficiency demands conservation in a realtively closed system, and even were the system not closed, excuses to grant exceptions are subject to high standards when having something immediately is more important than doing it right.

i know that talking about population control opens a whole can of worms (which ought to be conserved, poor things), and there have been way too many really ugly things come out of that kind of discussion, like eugnecs and genocide, for example. And there's always the issues of who gets to decide who can have how many children, and what the criteria are for making the decisions. But we have got to provide those answers, and soon, or the fate of the world's tuna and polar bears either moot or among the least of all our species' worries.

Have a nice day,
billy rainbow



]]> Comment #4 by nereid http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Mon, 06 Apr 2009 17:36:28 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/4 Seriously there is a strange disconnect that exists between conserving a vital and important organism and the idea that eating it is good for us.  It won't be good for us if they're all gone.

]]> Seriously there is a strange disconnect that exists between conserving a vital and important organism and the idea that eating it is good for us.  It won't be good for us if they're all gone.

]]> Comment #5 by kipchoge http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Mon, 06 Apr 2009 19:33:03 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/5 Although your conclusion may be correct (I wouldn't know), the issue doesn't seem quite so cut and dry. The NOAA site that Umbra refers us to says this: "Yellowfin tuna are often found in association with various species of dolphin. Some fishermen have taken advantage of this by setting their nets around the dolphin herds in order to catch the large tuna beneath them. In the 1970s, dolphin mortality was estimated to be hundreds of thousands of dolphins per year. Now, after continued research, improvements in fishing gear and techniques, and adoption of international agreements, dolphin mortality has been reduced to under 1,000 dolphins annually. For more information, see NOAA's www.dolphinsafe.gov." (my bolding)

]]> Although your conclusion may be correct (I wouldn't know), the issue doesn't seem quite so cut and dry. The NOAA site that Umbra refers us to says this: "Yellowfin tuna are often found in association with various species of dolphin. Some fishermen have taken advantage of this by setting their nets around the dolphin herds in order to catch the large tuna beneath them. In the 1970s, dolphin mortality was estimated to be hundreds of thousands of dolphins per year. Now, after continued research, improvements in fishing gear and techniques, and adoption of international agreements, dolphin mortality has been reduced to under 1,000 dolphins annually. For more information, see NOAA's www.dolphinsafe.gov." (my bolding)

]]> Comment #6 by Pangolin http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/ Tue, 07 Apr 2009 19:42:36 -0700 http://www.grist.org/article/2009-04-06-umbra-on-tuna-and-mercury/6 I often wonder if Peak Oil will make much of our ocean fisheries arguments moot. We can only catch great masses of deep ocean tuna by sending great fleets of diesel powered fishing vessels after them. With the energy used to catch the tuna heavily subsidized I suspect that eating a can of tuna is the energy equivalent of eating two cans worth of petroleum.

Right now oil prices have collapsed in part because the shipping industry is idled. That's not going to continue forever. At some point declines in oil production will price out certain classes of fisherman and restrict the ranges of others. Whether the tuna can survive longer than the tuna fleets remains to be seen.



]]> I often wonder if Peak Oil will make much of our ocean fisheries arguments moot. We can only catch great masses of deep ocean tuna by sending great fleets of diesel powered fishing vessels after them. With the energy used to catch the tuna heavily subsidized I suspect that eating a can of tuna is the energy equivalent of eating two cans worth of petroleum.

Right now oil prices have collapsed in part because the shipping industry is idled. That's not going to continue forever. At some point declines in oil production will price out certain classes of fisherman and restrict the ranges of others. Whether the tuna can survive longer than the tuna fleets remains to be seen.



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