+1 for headline writing El Reg.
A scientist has used Google Earth to uncover a Middle Eastern fish scam which could mean that six times more sea dwellers are caught than is officially reported. Dalal Al-Abdulrazzak wanted to suss out whether fishermen in the Persian Gulf were telling the truth about how many fish they landed. She carried out the "first …
Wednesday 27th November 2013 21:00 GMT Don Jefe
Of course the yield from the traditional traps is grossly under reported. All the people that have invested in technological solutions would be royally pissed off if a bunch of poor villagers were harvesting enough fish to generate profit but hadn't made big tech investments. It simply isn't fair I tell you!
That situation is true for many other things as well. As a civilization we have a fairly extreme bias toward technological solutions. If it's new, presented well and made out of something 'exotic' it simply must be better. If you persist in using the old/traditional methods you're considered either a Luddite, outdated, or simply stupid. Thing is, it's often the case that old solutions which developed to solve a specific problem and were refined for generations are superior.
Old isn't always best, but neither is new. You've got to figure out where the truth is. It's very rare that any new technology will instantly outperform the established ways. It might eventually, but often you find that after a technology has matured there is no overall gain, you've just got something that's more difficult to maintain.
Thursday 28th November 2013 07:17 GMT noem
I'm quite sure that was not the point of the paper. The reason for examining the fishing weirs via satellite was to estimate the impact of illegal fishing practices. Though efficient, the problem with fishing weirs is that mostly juvenile fish swim close to the shore, ergo weirs primarily catch juvenile fish. As they are obviously smaller than adults, the weight discrepancy must be accounted for with additional numbers of fish caught for the same tonnage. Fishing weirs are banned in the gulf and elsewhere because they decimate the juvenile fish population (meaning even less fish growing to adulthood to have little fish babies) and thus are not a sustainable method of commercial fishing.
From the source science journal:
"Although regulations governing fishing effort (e.g. fishing licences and spatial restrictions) in the Persian Gulf have been implemented since the 1960s, most stocks are either fully or overexploited (Grandcourt, 2012). This is partly because fisheries management (if any) is based on unreliable fishery data and limited stock assessments, and also because weak or ill-enforced regulations are commonplace. Fishery agencies in the area tend to be development focused, rather than seeking to implement long-term sustainability plans (Grandcourt, 2012).
In the case of Qatar, our methods revealed 17 operating weirs (14 visible directly and 3 added to compensate for poor resolution and imagery availability), despite their ban in 1994 (M.S. Al-Muhindi, Ministry of Fisheries, pers. comm.).
Because weir catches in the Persian Gulf consist mostly of juvenile commercially important species (Tharwat, 2003; Al-Baz et al., 2007), growth overfishing can occur even when certain spatial restrictions (e.g. spatial closures) are put into place."
I like to think of the world and the criterion we live by as dynamic and when the exigencies of the present diverge from those of the past, we adapt. I always thought this was the greatest strength/trait in our species, perpetually developing the next tool to fit the circumstance. Though I would tend to agree that the new isn't always ideal and that we should proceed with great care, I must admit that I have a far greater fear of stagnation.
Friday 29th November 2013 19:00 GMT PeteA
Thing is, though, these disastrous weirs seem to have worked pretty for a few millenia without destroying the fish stocks until the modern trawler came along. Note that the quote states "most stocks are either fully or overexploited (Grandcourt, 2012)". The relevant part is "fully or" - in other words, the damn locals are catching it all and there's nothing left for The Fishing Industry.
It'd be interesting to know the split between areas which are overfished and those which are just fully utilised in some way. I suspect that areas which catch mainly juveniles are probably much better able to recover than those where the adult breeding stock has been destroyed and you just have a few juveniles left over.
Saturday 30th November 2013 00:09 GMT noem
A quick gander at the Wikipedia world population page will show you just how much we've grown from just the 1800s (http://en.wikipedia.org/wiki/World_population). The sheer amount of people that need to be satisfied by a given resource is not even remotely the same as "a few millennia" ago, even if we were to shorten the time period to a single century ago it would still not even be close. Part of adapting to the pressure of having more people on the planet is utilizing resources in the most efficient way possible. Here's some quick critical thinking questions that should alleviate your suspicions:
If no new juveniles make it to adulthood, what does that do to a dwindling population's genetic diversity?
How does decreased genetic diversity hurt a species when its environment changes?
If each person has to eat a set portion of fish a day and a juvenile weighs a tenth of the adult weight how many fish do you have to catch to get the same portion?
If you catch one adult for every ten juvenile how many more fish can be born when the juveniles mature?
If you change from standard commercial fishing practice to solely utilizing weirs, how does that change the ratio of juvenile to adult caught?
Is a population considered sustainable if there are no new breeding stock?
Given that weir catch smaller fish what does this do to the cost (energy, time, cost to end consumer) of processing a set tonnage of fish?
Over fishing is a serious problem, and the fact that weirs kill many times the fish for the same tonnage only compounds it. Ultimately it creates a condition where there is less available breeding stock. When you consider the question of genetic diversity and expected environmental changes to occur in the next few decades (global warming), the genetic stagnation that weirs uniquely induce is especially troubling. That is not to say that commercial over fishing is OK, it's still very bad, but your proposal that juveniles be caught instead of adults, doesn't make sense when all you would have to do is over fish the juvenile population for as short a period as the average adult life span for the given species and it would then be trivial to demonstrate the cause for a particular fish's extinction.