Prawn
farming is destructive
updated
Dec 2019
if
you learn only 3 things about the issue...
 Commercial prawn farms can be highly destructive.
Find out where your prawns come from.
Eat
less prawns, don't throw prawns away. |
|
Traditional
prawn farming is sustainable: In traditional prawn farming,
a small prawn pond is created in the mangrove with bunds or a wall
of mud and earth. A sluice gate controls the water flowing in and
out of the pond. At first, the sluice gate is kept closed so that
little prawns that naturally occur in the water can develop within
the pond. After some time, the sluice gate is opened and the water
is let out of the pond, but a net is placed at the sluice gate to
catch any prawns that move out with the water.
Large
scale-prawn farming is destructive: The large prawns
that we eat often come from prawn farms or are harvested from the
wild by trawling or traps. While traditional farming and harvesting
methods are sustainable, large-scale commercial prawn farms and
prawn trawling are more destructive and unsustainable.
How do large scale commercial prawn farms impact the environment?
- Destroying
large tracks of mangroves and other intertidal habitats to create
the farms;
- Harvesting
egg-bearing adults from the wild to provide stock for the farms;
- Introducing
non-native prawns, which requires foreign exchange. These could
upset the natural balance if they escape;
- The prawns
are fed with wild caught fish;
- The prawn
ponds are treated with antibiotics, pesticides and water additives
to prevent diseases or boost growth.
- Water from
these farms, laden with prawn waste and chemicals, further damage
the surroundings;
- Diseases
that develop resistance to antibiotics devastate not only prawn
farms but also other aquacultures and marine wildlife; and
- Saltwater
from the ponds eventually seep into groundwater and affects supplies
of freshwater to humans and wildlife in surrounding areas.
How do large
scale prawn farms impact the local population?
- These farms
are capital-intensive and do not generate jobs for the low income
low skill people that live near the mangroves.
- The farms
displace these locals, who previously relied on the mangroves
for food and income.
Why should
we care that mangroves are lost?
- Mangroves
provide income and food for subsistence coastal dwellers. These
families are displaced in such developments.
- Mangroves
are an important part of the spectrum of marine ecosystems that
extend to reefs. Many commercially important fish and other seafood
spend their younger days in the shelter of mangroves.
- Mangrove
protect the land from events such as tsunamis, cyclones and high
waves. The destruction of mangroves for shrimp farming is believed
to have aggravated the impact of the Indian Ocean Tsunami of Dec
04.
What about
prawns caught by trawling?
- Dragging
large heavy nets repeatedly over shallow areas. This damages everything
on the sea bottom and has been equated to strip mining the reefs
and shores. Recovery of the habitat can take 1-20 years.
- An enormous
waste: commercially valuable prawns often make up only 10% of
what is caught, the rest is thrown back often dead. In some estimates,
for every 1kg of prawns caught, 9-12kg of 'by-catch' are thrown
away, amounting to 55 000 tonnes of discards every year. The 'by-catch'
includes juvenile fishes and sea turtles.
- Trawling
is seen by some to be a key cause of the decline of some sea turtle
species.
So what
should we do about eating prawns?
- Find out
where your prawns come from.
- Tell your
supplier and supermarket you prefer prawns from sustainable sources.
- Eat less
prawns.
- Eat what
you take. Don't throw away prawns! (or any food for that matter).
Many marine animals have died and people have suffered to put
that prawn on your plate!
Status
and threats: Some of our shrimps and prawns are listed
among the threatened animals of Singapore. However, like other creatures
of the intertidal zone, they are all affected by human activities
such as reclamation and pollution. Trampling by careless visitors
and overharvesting can also have an impact on local populations. |
Didier Millet, Malaysia. 144 pp.