Aquaculture, Fish, Land — by Geoff Lawton March 7, 2011
Like the Hawaiian salt water fish ponds, there are some traditional Chinese salt water fish ponds that work very well. Many of these have been modernised into fishing and angling ponds to capitalise on the urban population, but when you look into the traditional systems there are some very interesting variations.
One such system we visited recently used a mangrove system with wonderful simplicity to reduce work load and work in harmony with the naturally occurring, abundant resources.
This system uses a gate between the ocean and the mangroves which can be opened to allow juvenile prawns into the mangrove system, as they are looking for a safe habitat in which to mature. Once they have moved inside, and the mangroves are fully stocked, the gate is closed.
The gate is designed to allow the water to still flow in and out with the tides, through screened pipes that keep the prawns inside. The prawns will then grow out, eating natural feed, in their natural tidal mangrove environment.
When the prawns have matured enough they will naturally try to move to the open ocean to breed. At this stage the gate will be netted from the outside and then on the outflowing tide the gates are opened and the prawns will be caught in the nets for an easy harvest. The largest of the prawns and therefore the best breeders are selected and set free to extend the breeding population, very similar to techniques that are used in Hawaii with fish in the loko i`a salt water fish ponds.
This is a wonderful system that allows harvest of wild life cycles using enhanced natural habitat landscape of nature for productivity. We need to look at what other areas this knowledge can be applied to and apply them rather than continue the current destructive trends.