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Sharks in Serious Danger
jd writes "According to the BBC, shark populations in the Atlantic declined on average 75% (the hammerhead faring worst at 86% loss) in the past 15 years. This ain't trivial. Many sharks produce one pup a year, if that, and less than half of those survive to adulthood. Sharks are essential to the health of the oceans, so this is not a trivial concern. They're mostly in decline because some idiots like to cut off the dorsal fin, to make soup. (You kill a lot of sharks, and get gristle stew as a reward.) Others die because of paranoia, and yet more because of psychotic trophy hunters. If sharks do die out, they will be the longest-lived species that humanity has exterminated. (Who needs Daleks? We're doing just fine on our own... :()"
As a conservationist and an avid scuba diver, I am wondering if their data collection methods could be incorrect. 75 percent seems a bit much.
Never overestimate the end user. -jeramy b. smith
to survival of the fittest?
If an animal goes extinct for any reason, doesn't that just mean it wasn't "fittest"?
Does it matter -- and I'm not being contentious -- how much of the animal we eat, where is the point that we're destroying the population? A dead shark is a dead shark.
... and then the fishery collapsed. Completely, a cliff, not a gradual decline. It shows how things make not wrok intuitively, and after you pass a certain point simply easing off on the take won't fix it.
There is an aesthetic thing to it, this efficiency business, and it makes sense only if the result is that we kill fewer animals (or sharks) and, most of all, don't destroy the population.
There is a wonder chart at the Monterery Aquarium in California, showing the haul of sardines year after year in 40's (or so). Every year the catch grew
I know this was modded as flamebait, because, well...it is flamebait. But it does raise an interesting issue.
Fitness is a measure of average reproductive success. If these shark populations are in fact markedly declining then, yes, these sharks do not seem to be very fit. Fitness is a function of environment. You might say that an individual shark has an particular fitness per particular environmental state. When environments (here defined as including other organisms (including us and other sharks)) change, fitness can change.
However, even if this statement might be more or less factual, this statement was used to say something else entirely: that it doesn't matter, ethically or practically, that sharks are dying out...because well its how the natural world works.
But this is a rather weak arguement. First, physical facts, alone, probably do not unambiguously indicate ethical values. This is known as the fact-value distinction. This means that the fact that sharks are not currently fit does not justify our unconcern for their lack of fitness. Still, it does not indicate the contrary either. Personally, I think that it is a very complicated ethical problem. I think we should beware a tendency towards thinking in terms of "presevation" rather than "stewardship." Just because something is natural, doesn't imply that it is the best of possibilities.
Regardless of the ethics of sharks survival or (non-survival), the decline of shark populations should concern us for other, very pragmatic, reasons. The world's ecosystem is vastly dynamic and inter-connected. 9999999 Changes in one component of the system could have complex, unpredictable, and sometimes dramatic global effects. The world is not so simple as we like to believe. It actually doesn't take much to push a system into a positive feed-back loop that reinfoces some tendency...say an ice-age. And for those who pooh pooh this as some kind of paranoid catastrophism need to take a little closer look at the earth's history (or a look at most of the other planets in our solar system). It is not unusual. It happens all the time.
Logic, macros, and more
chances of actually getting them into practice.
Well if its not going to work, lets just leave it all alone. Doesnt matter. Y'nkow women are "never going to get the vote", so why do they bother. The jamacans arent going to win the bobsled race, so no point in entering. The RIAA isnt going to have a change of heart and campaign against the DMCA, so theres no point in saying anything. Blacks will always be inferior, so why all this "civil rights" stuff.
Just because change is hard shouldnt mean we just go "Oh well".
Without discussion, change doesnt happen. Oh, and It's my right to think that people that kill endangered species, whether it be shark hunters, or the fleets that overfish the North Sea, are equally stupid as each other.
Ecological niches are not static. Wiping out a species has ripple effects thoughout the ecosystem.
Not to mention that the current rate of specied extintion is like nothing since the dinosaurs were wiped out and the whole ecosytem pretty much got rebuilt. Since we are a part of this ecosystem, fucking about with it is not intelligent behavior.
Sometimes I imagine the first blue-green algea having this conversation:
"Hey, all this oxygen we're releasing...it's going to mess up the ecosystem. You know, we're destroying all sort of anaerobic bacteria."
"Ah, screw them if they can't adapt."
And so evolution creates an adaptation - primitive animals. That feed on algea.
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood