TRANSCRIPT - Dr. Jurgene Primavera
Primavera is Senior Scientist at the Aquaculture Department
of the Southeast Asian Fisheries Development Center in Tigbauan,
Youve shown us a lot of different types of aquaculture. Could
you tell us about each one?
with the milkfish, its the most important farmed fish in the
Philippinesbecause its a local a food and mostly its
growth depends on wild frywhich can be seasonal, which can
be expensive. So, if you produce hatchery fry that will be a great
help to the industry.
this is a carnivore its mostly aimed at the
upscale restaurants, hotels, also the Chinese population in the
Philippines which really likes grouper for sweet/sour fish. The
problem with grouper is that it is a carnivore and it is fed trash
fish, which in the Philippines can mean fish of people-food fish,
so it competes with humans. So the big research challenge for grouper
is to develop food substitutions that are not so dependent on fish,
especially, fish meal or trash fish.
The mud crab
or the mangrove crab and again, this one can be grown either
in open water but especially mangrove ponds and pens where you can
integrate aquaculture with trees and its very environmentally
friendly. But again, the problem with mud crab culture is the feeds
because its a carnivore needs fish meal in pellets
of trash fish. So as with grouper, the research is to develop feed
substitutes that are easily available and do not compete with for-human
Next was the
abalone. Abalone is important for local communities in terms of
gleaners. They are gleaned when the tide goes out, during low tide.
The women and children harvest it even in the deeper parts. They
harvest abalone also for its shell thats used in making buttons
and other items. So, the populations are in decline and if we can
produce the seed in hatcheries and use these seeds for stock enhancement
of natural populations, then we can give livelihood to coastal communities.
And this is
the same rationale for sea horse research effort. Although theres
a specific cause for the decline of sea horses the Chinese
market that pays premium price for dried sea horses because they
are considered aphrodisiacs. So they have declined in the wind and
if we can produce seeds in captivity and develop some kind of grow-out
or sea ranching, then this will relieve pressure on wild populations
of sea horses.
It sounded like you had a lot of enthusiasm for milkfish, one reason
being that its an herbivore. If aquaculture is going to feed
the world, does herbivorous fish hold the most amount of hope?
I said that
its true that milkfish are herbivores and it is when you have
herbivores like milkfish, carps and filter feeding mollusks
bivalves that aquaculture in creating new protein is realized.
But in contrast when you grow carnivores like shrimp, salmon,
mud crabs, groupers then its not totally new protein
because its re-packaging fish meal thats from captured
fisheries into aquaculture protein.
And the ration
is like two to four kilos of wild fish to produce one kilo of cultured
fish shrimp, salmon, whatever it is. So be that as it may,
there is troubling science in the industry because theres
a trend towards intensification even of the omnivores and the herbivores
like milkfish tilapia. So intensification means higher stocking
densities, greater biomass, greater food requirements, so natural
productivity can no longer sustain such high biomass and you need
supplementary feeding and this means pellets. And because not much
is known about the feed requirements of these herbivores and carnivores,
the feed industry plays it safe and puts in a lot of fish meal exceeding
what would be the required levels. So essentially youre shifting
the mode from creating new protein to the carnivore mode where you
use fish meal. So the promise of aquaculture maybe its
a bit of a traitor, in a sense. Youre just taking away from
captured fisheries and placing in aquaculture.
Now the literature
in ecology is coming up with all these values in mangrove both in
the tree products as well as the aquatic products the fish,
the crustaceans and the mollusks that you get. Both in mangroves
and near shore or offshore, where the mangroves act as nurseries
to these commercially important fish and invertebrates. So with
the importance of mangroves, not just the products, but also as
coastal buffers and filtration services and so many other non-valued
services, mangroves are important in themselves and they should
be conserved. So what is exciting about the project that you saw,
the pens and the ponds, they give the option of conserving the mangrove.
Its really a major shift away from what at least the Philippino
fish farmers have known for so long: that when you build a farm
you have to do so at the expense of the mangrove forests. So we
can integrate the trees together with the ponds. One way is physically
integrating, in a single pond or pen, you have the water where you
grow the crabs, the fish, whatever and you have the trees. But another
way also is you can have open water ponds where you grow the fish
or the shrimp and have a mangrove buffer zone around so that the
mangrove zone can absorb the nutrients that are coming out of the
fish or the shrimp pond. So that is also a sustainable blackfish
aquaculture because you still keep a mangrove zone or a mangrove
Could you speak about unsustainable aquaculture again?
We all know
about the decline of fisheries wild fisheries and
we all know the reasons: illegal fishing practices, dynamite fishing,
cyanide, fine mesh nets, the loss of mangrove nurseries, coral reefs
and so many other factors. So, really to improve sustainability
of fisheries, you have to address those issues. But the danger in
promoting aquaculture as a panacea is that if you put enough support
for aquaculture, then aquaculture will provide the loss in wild
fisheries. Well solve all the problems and then you feel good.
Youre not really solving the fisheries problems. So that is
Is aquaculture the answer?
can supplement the world food supply, but not completely replace
our wild fisheries. Perhaps if focus were kept on the new protein
species like the herbivores, the omnivores, the filter feeding mollusks,
and keep the way they feed like not feeding the herbivores
high fish pellet then the promise of aquaculture making new
protein can really be maximized and the contribution world food
supply would be maximized. But still, you need the fisheries component.
And I dont see it as a competition between the two sectors.
I think they really should go hand in hand because theres
a lot of interfacing between capture-fishing and aquaculture. And
this kind of thing should be maximized.
I think its
the politicians and some agencies that prefer to polarize things,
you know. That this is fishery and this is aquaculture, in an effort
to maximize fundraising for their own territories. Which is a very
sectoral way of cutting up things when in fact you have gradients
and you have synergizing that are there, that get lost.