Pare ca nu prea intelegeti situatia. Faptul ca acum omenirea a depasit deja
capacitatea de suport a Planetei, nu va fi schimbat de nici un fel de detaliu
tehnologic. Daca populatia umana ar fi stabila numeric, iar economia nu ar avea
nevoie din ce in ce mai mare de energie, resurse de tot felul si nu ar produce
poluare globala din ce in ce mai mare, poate ca o asemenea chestiune,
inbunatatirea tehnologiei ar fi sesizabil prin reducerea impactului global de
mediu. Dar asa... ?
Acvacultura, la fel ca orice indeletnicire umana, are si impact de mediu. In
articol se si aminteste de asta:
"Aquaculture (...) ... even with the vast increase of farm-raised fish, the
farming of salmon and other fish-eating species keeps pressure on the oceans
because massive amounts of catch are needed to feed them. The aquaculture of
herbivorous fishes, such as carps, tilapia and catfish, is vastly more
sustainable, yet even in this case, aquaculture poses significant ecological
challenges. Aquaculture can spread diseases from farmed to wild fishes, pollute
nearby wars with excess nutrient loads, lead to habitat destruction such as the
clearing of mangroves for shrimp farming, and threaten genetic diversity
through the release of farmed species into the wild."
Hai sa zicem ca se imbunatateste situatia acvaculturii. Va fi mai performanta.
va produce mai multa hrana pentru om. Dar daca ea devine mai raspandita din
cauza nevoii de proteine animale ale unei populatii umane in crestere, daca
creste dimensiunea fenomenului acvaculturii, chiar si daca performanta per
unitate poate sa fie eventual inbunatatita, imactul de mediu are tendinte sa
creasca.
Sa nu mai zic de faptul ca oamenii nu au nevoie doar de mancare, ci si de
energie, locuinta, milioane de diferite obiecte, care toate consuma resurse,
polueaza, etc etc... Asa ca a astepta de la acvacultura o rezolvare a
problemelor, a zice ca "previziunile pesimiste ale unor extremisti ecologisti
sau adepti ai teoriei conspiratiei sunt infirmate zi de zi de noile progrese
tehnologice" este o naivitate extraordinar de mare.
Eu nu cred ca tehnologia mai performanta (in sensul de reducere a impactului
de mediu) poate sa tina pasul cu cresterea demografica, presiunea uriasa pe
resursele existente, dorinta de crestere economica fara limite in toate
populatiile umane ale planetei nostre etc. Cred ca este adevarat doar citatul
in felul urmator:
"Environmental sustainability is already very difficult to achieve with
todays 6.6 billion people and average economic output of $8,000 per person. By
2050 the earth could be home to more than nine billion people with an average
output of $20,000 or more, putting vastly greater pressures on the Earths
ecosystems.. .(...)"
Peter
Adrian AVARVAREI <[EMAIL PROTECTED]> wrote: Iata ca previziunile
pesimiste ale unor extremisti ecologisti sau adepti ai teoriei conspiratiei
sunt infirmate zi de zi de noile progrese tehnologice...
A.A.
---------------------------------
Aquaculture can maintain living standards while averting the ruin of the
oceans
By Jeffrey D. Sachs
Environmental sustainability is already very difficult to achieve with
todays 6.6 billion people and average economic output of $8,000 per person. By
2050 the earth could be home to more than nine billion people with an average
output of $20,000 or more, putting vastly greater pressures on the Earths
ecosystems if technologies of production and consumption remain largely
unchanged. Many environmentalists take it for granted that richer countries
will have to cut their consumption sharply to stave off ecological disaster.
There is another approach. Global public policies and market institutions can
promote new technologies that raise living standards yet reduce human impact on
the environment. A crucial group of such technologies is aquaculture, the
farming of marine animals, which can support growing human consumption of fish
and other aquatic species while relieving intense pressures on ocean
ecosystems. The rapid development of aquaculture in recent years has been
likened to a Blue Revolution that matches the Green Revolution of higher
grain yields from the 1950s onward.
Between 1950 and today the total landed catch from open- and inland-sea
fishing almost quintupled, from around 20 million to about 95 million metric
tons. Both higher demand from rising world incomes and higher supply from more
powerful fishing vessels contributed to the surge in the catch and consumption
of fish. So, too, did large and misguided subsidies to fishing fleets,
reflecting the political power of geographically concentrated fishing
communities and industries. The world put itself on a course to gut ocean
ecosystems, with devastating consequences.
Into the breach has arrived the Blue Revolution, first in China, and now in
many other parts of the world. Aquaculture yields have increased from around
two million metric tons in 1950 to almost 50 million metric tons today. Thus,
even though the global fish catch peaked in the late 1980s, aquaculture has
enabled a continuing rise in human consumption of fish. China now accounts for
around two thirds of total aquaculture production worldwide by weight and
roughly half by market value.
Fish farming in China is of course an ancient activity, with several carp
species grown among rice fields for thousands of years. The inter-mixing of
rice production with fish farming, rather than with animal husbandry as in
Europe and the Americas, made good ecological and economic sense in densely
populated China. A cow requires around seven kilograms of feed grain for each
kilo of meat, while a carp requires around three kilos or less. Fish farming
economizes on feed grain, and of course on the land area needed to produce it.
The exciting news, however, is that recently Chinese scientists have both
improved the efficiency of aquaculture and revolutionized the range of species
that can be farmed. An insightful study by coastal ecologist Carlos Duarte and
his colleagues in the April 7 Science documents the dramatic rate of
domestication and commercialization of marine species. Of the more than 400
farmed marine species, as many as 106 have been domesticated in the past decade
alone. In contrast, there has been almost no concurrent increase in the number
of domesticated land species.
Aquaculture by itself will not solve the crises facing marine ecosystems. For
instance, even with the vast increase of farm-raised fish, the farming of
salmon and other fish-eating species keeps pressure on the oceans because
massive amounts of catch are needed to feed them. The aquaculture of
herbivorous fishes, such as carps, tilapia and catfish, is vastly more
sustainable, yet even in this case, aquaculture poses significant ecological
challenges. Aquaculture can spread diseases from farmed to wild fishes, pollute
nearby wars with excess nutrient loads, lead to habitat destruction such as the
clearing of mangroves for shrimp farming, and threaten genetic diversity
through the release of farmed species into the wild. Yet better aquaculture
technologies are already evolving rapidly to face these challenges. As with any
promising technological development, public policies will play a critical role
through a judicious use of policy carrots and sticks. Public funds and
prizes should be used to promote research on aquaculture technologies.
At the same time, the pillaging of the oceans will continue unless regulations
such as tradable fishing permits that limit the total catch to sustainable
levels are also used to contain the exploitation of the ocean commons.
Subsidies for excessive ocean fishing should also be slashed. Egregious
practices such as bottom trawling on seamounts should be outlawed by
international agreement. With sensible global policies, the Blue Revolution can
indeed become a major force for improved human nutrition, economic well-being
and environmental sustainability.
---------------------------------
Jeffrey D. Sachs is director of the Earth Institute at Columbia University
(www.earth.columbia.edu)
---------------------------------
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