Saturday, January 15, 2011

Doug Perrine about eating Cownose Rays!


I've said it before, Doug Perrine is Royalty.
Not only is he one of the nicest guys around, not only is he one of the pre-eminent underwater photojournalists - he is also a staunch and at the same time, extremely well documented marine conservationist.

Case in point, his comment to this article in NGM.
Surprise surprise, when he posted it, he got the following reply Your comment has been saved. Comments are moderated and will not appear until approved by the author - and it very much appears like the author may still be pondering. I wonder why? :)
Doug is referencing this seminal paper (longer synopsis here), probably the first such study that documented how removing Sharks could trigger trophic cascades (another example here).

As a caveat, it must be said that this does NOT apply to all Sharks!
It only applies to determined species in determined habitats where they act as apex predators and keystone species - other, generally smaller species of Sharks like e.g. Spiny Dogfish are considered mesopredators and may in fact profit from the removal of apex predators!

But I'm digressing as always.
Here is Doug's comment, unabridged - let's see if Jeremy Berlin will eventually have the guts to approve its posting on NGM. Anybody taking bets?
Bravo Doug!

Jeremy Berlin’s short and intriguing article in the January issue of NGM, “Eat a Ray, Save the Bay,” left me hungry for more information.

What are these “shellfish” that the rays are “gobbling?”
Are they, by any chance commercially important species of mollusks and crustaceans that have been in severe decline for years due to over-harvesting and habitat destruction by humans?
Any chance that humans have also been “gobbling” these species?


And what about the grass beds that the rays are “roiling?”
Would these, by any chance, be the same grassbeds that have been in decline since humans first settled around Chesapeake Bay, as a result of pollution, poor watershed management, mechanical destruction by dredging (for some of those unnamed “shellfish”) and boat propellers, etc.?


Why is it that “predators like coastal sharks have declined?”
Does it have anything to do with the rapacious, cruel, and obscenely wasteful fishery for shark fins to supply a nutrition-free status-enhancing soup ingredient for Chinese celebrations?

Have the unidentified “area officials” considered the alternative of rebuilding healthy populations of predators in order to ensure a resilient and balanced ecosystem?
When the writer refers to “the observed spike in cownoses, though untallied,” may I presume that the meaning is that there are no reliable population estimates for this species either before or after the sharks and shellfish were both overfished, and certainly not before the entire ecology of the Bay was drastically altered at human hands?


Are the “area officials” aware of the life history characteristics of elasmobranchs (sharks and rays), such as extremely low fecundity, slow growth, and delayed maturity, which make them notoriously poor candidates for a commercial fishery?
Can they name a single truly sustainable fishery for any species of elasmobranch? May I suggest an alternative to the moniker “Chesapeake ray?”
How about “scapegoat ray?”


One final question: when did National Geographic Magazine start promoting resource exploitation schemes clearly developed by commercial fishermen and their allies in local government without consulting scientists with expertise in the field?

In China, bamboo forests have been destroyed for agriculture and development and pandas are gobbling the remaining bamboo.
Can we expect to see panda recipes in National Geographic soon?


As I said: Royalty!

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