Tuesday, May 1, 2007

Shrimps and Prawns: Do we know where they come from?

One NAKED fact

Do you like to eat prawns and shrimps? Do you know their life cycle?

NF#1: Prawn nursery: Most adult shrimps migrate to deeper waters to breed and release their eggs. Eggs usually hatch quickly, within a day or so. After hatching from the egg, the larvae look nothing like the adults! These larvae drift with the plankton, changing shape as they develop further. Eventually, they look more shrimp-like and migrate back to shallow waters. Here they develop into mature adults before starting the cycle all over again.

The following is a rather depressing approach to shrimps and prawns...
but this helps people understand the ecological cost of our seafood

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.

Commercial prawn farming often involves:
  • 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 could upset the natural balance if they escape;
  • Adding chemicals to the water to prevent diseases or boost growth. These affect surrounding wildlife;
  • Releasing large amounts of waste water from the farms that poison the surrounding habitats; and
  • Saltwater from the ponds eventually seep into groundwater and affects supplies of freshwater to humans and wildlife in surrounding areas.
Large-scale trawling often involves:
  • Dragging large heavy nets repeatedly over shallow areas. This damages everything on the sea bottom. 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.
The destruction of mangroves for shrimp farming is believed to have aggravated the impact of the Indian Ocean Tsunami of Dec 04.

Some shrimps and prawns that may be encountered on Sentosa
Larger prawns are usually only active at night. During the day, some bury themselves in sand. Others hide elsewhere.Tiny shrimps are commonly seen all over the shore; among seaweeds, on corals, just on the bottom of shallow pools. Some have a red 'nose'.

No comments: