February 18, 2008
Shark Numbers In Sharp Decline Due To Overfishing
Yet another sign that the human population has become too big:
Sharks are disappearing from the world’s oceans. The numbers of many large shark species have declined by more than half due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and swordfish fisheries, where millions of sharks are taken as bycatch each year.
This is going to get much worse. The human population is increasing and Asian industrialization is massively increasing the number of people who can afford to eat fish caught in the ocean.
Now, the global status of large sharks has been assessed by the World Conservation Union (IUCN), which is widely recognized as the most comprehensive, scientific-based information source on the threat status of plants and animals.
“As a result of high and mostly unrestricted fishing pressure, many sharks are now considered to be at risk of extinction,” explained Julia Baum, a member of the IUCN’s Shark Specialist Group who will be speaking at the American Association for the Advancement of Science (AAAS) Annual Conference in Boston, which runs from February 14 to 18. She will outline management measures required to conserve sharks at an afternoon press conference on February 17.
“Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red List as globally ‘endangered’ due to overfishing and high demand for its valuable fins in the shark fin trade,” added Baum, who is an NSERC Postdoctoral Fellow at Scripps Institution of Oceanography.
The capture of sharks makes more fish from lower in the food chain available for human consumption. Humans are basically displacing other predators at the top of large numbers of food chains.
It is always open season in shark fishing in international waters. Every year the amount of capital available to sweep the oceans free of fish keeps going up.
Baum pointed out that fishing for sharks in international waters is unrestricted, and she supports a recently adopted United Nations resolution calling for immediate shark catch limits as well as a meaningful ban on shark finning (the practice of removing only a shark’s fins and dumping the still live but now helpless shark into the ocean to die).
Will growing Asian buying power overwhelm any attempt to stop fisheries shrinkage?
I repeat my prior request for this topic, as it means the difference between a drastically decreased oceanic carrying capacity -- starting at the base of the food chain -- due to human activity and a drastically increased oceanic carrying capacity -- starting at the base of the food chain -- due to human activity:
I've seen many references to "the cause" of oceanic "dead zones" being nutrients but this seems paradoxical:
Yes I know the story: nutrients create algae blooms which then die and decay thereby robbing the ocean of oxygen.
What I'm referring to as a seeming "paradox" is not only the fact that the base of the food chain is dramatically expanded by nutrients --
but that the organisms making up this foundation produce _oxygen_ from photosynthesis supporting algae grazers with both food _and_ oxygen.
Why don't the smaller, rapidly-reproducing zooplankton take up the gauntlet?
Virtually all of the articles I've read on hypoxic waters and dead zones fail to address this paradox. I've only read one paper that
mentioned even an _hypothesis_ of how algae grazers fail to flourish -- referring to algae species that protect themselves with toxins.
But this doesn't ring true: Why would the most pioneering of algae species be the most protective of themselves when there is so much
opportunity to evolve optimizations for growth rather than defense against grazers?
The problem is NOT too many people.
The problem is that too many people eat too much meat, including exotic meats like shark fin soup.
If people ate meat just once a week, it would not only help the ecosystem, but society would be much healthier as well.
I would rather see it as a problem of underfarming than overfishing. Fishing is the last vestige of hunting in our agricultural society. A farmer makes sure that his livestock breeds the next generation. Who looks after the next generation of fish? If I can't be sure to keep the cows I raise, I won't raise them. In the sea, by stupidly short-sighted law, I can't own a block of ocean. Anyone could roll a boat through and take my carefully nurtured fish. So why care about breeding stock? Grab them all before the next guy. Thus socialism creates greed.
Until we learn the old lesson again and allow property in fishing grounds, various species of fish will keep being "endangered".
Of course the problem is too many people. People like meat. If you get more people you get more meat eaters. If you raise buying power thru industrialization then you get meat eaters who can afford to eat meat more often.
We have lots of farming on land. Yet in spite of intensive farming we are ripping down rain forests at a fast rate.
Really, our problem is too many people. Too many babies.
Randall, you said, "Really, our problem is too many people. Too many babies." In a way, it may be generous of you to treat the matter as "our problem." However, it seems the peoples who most often hear and repeat to each other the message that there are too many people having too many babies are precisely the peoples who are already at or below the replacement level of fertility. Many other peoples seem either not to have hear the message or not to care. I'm careful to speak of peoples rather than of nations in the contemporary sense of the word, because the dwindling of some peoples is obscured by the multiplication of little-assimilated immigrant peoples within the boundaries of those dwindlers' national boundaries.
If by "our problem," you mean that we dwindlers need to redouble our efforts to die out and leave the Earth to everyone whose parents have been shrewdly or just heedlessly fertile, then I can't imagine how you derive such self-destructive moralism from your science. However, if by "our problem," you mean it's our practical problem that our own liberal, secular, scientific, and/or technological peoples are dwindling, while others already have far greater numbers and still have higher fertility, it seems you're right. If you want a liberal, secular, scientific, technological future, it's also our problem to solve by prudent means.
It's not too many people. It's a failure to use our resources properly. If the rest of the world had the same agricultural productivity as the US, we could feed 10 billion people and return the Amazon to nature.
Switching the oceans from hunting to farming/ranching is long overdue. If we did that, we would see the same or greater increases in per hectare productivity that we've seen over the last 10,000 years on land, but in a few decades at most.
People (and their innovations) are the thing that's going to figure out how to get us out of our current jams. The more the merrier!