The World Oceans Now 70% Shark Free

wheresjim writes "According to a study published in The Proceedings of The Royal Society, the world's oceans are now about 70% shark free. This is a bad sign for the sharks, the oceans and of course, journalists during slow news cycles."

Comments

/. response.

[Janek Kozicki]

Nothing for you to see here, please move along

70% appropriate.

Either you're with us you're with the sharks.

[Anonymous Coward]

I am shocked to hear this kind of pro-shark fascism being spewed on Slashdot. As we all know, sharks are vile, evil creatures who are a danger and threat to all life and liberty.

Why do you hate America?

The other 30%

[yobjob]

Are circling around Australian beaches.

Re:The other 30%

[Fire Dragon]

Nope, they went to law-school.

Re:The other 30%

[jaymz168]

Or are delivering candygrams.

By volume?

[Toba82]

Does this mean that the ocean is 30% sharks by volume? I AM NEVER SWIMMING AGAIN!

Batman!

[broothal]

I blame Batman for dumping his anti-shark-spray into the ocean.

(if you get that joke you're really old)

Yes but...

[sirnuke]

What was the percentage in recent years? Assuming the trend is decreasing amount of sharks, how fast is it going? If ten years ago, the sharks percentage was decreasing at .0025/year, but now it's .005/year, that's probably really bad. If now the rate is now .001/year, that's more or less a good thing. At the highest point, what percentage of the ocean had sharks?

Kind of like having a 50% off sale without saying what the original or final price is. Sounds great...

Graphs are really nice.

Re:Yes but...

[Anonymous Coward]

The summary misinterpreted the article (yeah, BIG surprise). They haven't found 70% of the ocean is NOW shark-free. They have found that, all along, sharks only inhabit about 30% of the available ocean regions.

What the study found was that below a certain depth (2000 metres) there appear to be no shark species, even though the typical shark prey extend down to much deeper than that. So, while the researchers had assumed that sharks would move throughout the water column, and more species of depth-loving sharks would be found, none were below about 2000m.

This means that all current known shark species exist in only 30% of the total ocean volume (over 70% being below that 2000m depth). Which means that they are all in close proximity to humans and human fishing activity. Which means that they may be more susceptible to overfishing of that area, since they seem unable to spread to lower ocean levels (the so-called abyssal region) to find more food sources. The linked article suggests that there might be a lack of food sources at lower depths, but another summary I saw mentioned the presence of fish species below this depth - which might indicate that either the fish are in too low a number to sustain the sharks; the sharks are incapable of going to the lower depths due to physiology; or they can't compete with other predator species at those depths (eg. squid?).

Of course, other studies have indeed shown declining shark populations, and decreasing sizes of adult sharks of various species (such as white pointers and whale sharks) which indicates that there is increasing pressure on shark populations by overfishing of both them and their food sources... but this study didn't look at that.

Or read the abstract?

[Ksisanth]

See online journals of the Royal Society -- it can be found under Proceedings of the Royal Society B:Biological Sciences titled "The absence of sharks from abyssal regions of the world's oceans".

We propose that they are excluded from the abyss by high-energy demand, including an oil-rich liver for buoyancy, which cannot be sustained in extreme oligotrophic conditions. . . . All populations are therefore within reach of human fisheries, and there is no hidden reserve of chondrichthyan biomass or biodiversity in the deep sea.

Sharks aren't the only benchmark.

[Shag]

While sharks, as apex predators, are a good indicator of overall biodiversity / availability of tasty biomass in the oceans, figures on some other species are probably at least as alarming.

I've seen (at things like the UN informal consultative process on oceans and the law of the sea, and the 3rd global conference on oceans, coasts and islands just last month) presentations showing fisheries catch decade-by-decade worldwide, and the trends are just plain scary.

So many things are being done in totally unsustainable ways that popular tasty species have come close to being wiped out over large areas. Cod around Canada, for example. Tuna in some other areas.

I like tasty fish and don't want them to all go away. (Yes, here I am subscribing to sustainability defined as "making sure your grandkids get to hunt Bambi, too.")

Re:Bad for all of us

[Hektor_Troy]

Sure, but what about the poor Austrian fishermen? Why aren't you taking them into consideration with your "facts"?

Re:Bad for all of us

[tomrud]

> Sure, but what about the poor Austrian fishermen? Why aren't you taking them into consideration with your "facts"?

We should encurage them to get new jobs. In the Austrian Navy for example.

Re:Bad reporting

[panaceaa]

It's 70% free compared to what?

Only the Slashdot artcile has the "Now 70% Free" spin.

Once I noticed this and reread the article, it made a lot more sense -- but it's still a crap article. There's no mention of who the international team of scientists that conducted the study are, and therefore no connection with the scientist quoted and the study. It seems as if the quoted scientist used his opportunity to be quoted in an article to express concern about a real problem, overfishing, without actually knowing about the study itself. Unfortunately the writer took this spin and put it into the opening paragraph and completely threw off the importance of the study.

What really seems to have been discovered is that there aren't sharks 5,280 feet below sea-level. The original study suspects this is because there's no fish to eat down there, which is a pretty obvious fact considering there's no light down there and very high water pressure. And considering 70% of the world's ocean mass is below 5,280 feet, therefore sharks are not in 70% of the ocean.

oblig. fortune

[arabagast]

... So the documentary-makers stick with sharks. Generally, their
procedure is to scatter bleeding fish pieces around their boat, so as
to infest the waters. I would estimate that the primary food source of
sharks today is bleeding fish pieces scattered by people making
documentaries. Once the sharks arrive, they are generally fairly
listless. The general shark attitude seems to be: "Oh God, another
documentary." So the divers have to somehow goad them into attacking,
under the guise of Scientific Research. "We know very little about the
effect of electricity on sharks," the narrator will say, in a deeply
scientific voice. "That is why Todd is going to jab this Great White
in the testicles with a cattle prod." The divers keep this kind of
thing up until the shark finally gets irritated and snaps at them, and
then they act as though this was a totally unexpected and very
dangerous development, although clearly it is what they wanted all
along.
                                -- Dave Barry, "The Wonders of Sharks on TV"

Seems like the documentary people has stopped feeding the sharks