ANNEX IV
NATIONAL REPORT OF EGYPT
NATIONAL REPORT OF GREECE
NATIONAL REPORT OF TURKEY

EXTENSIVE FISH CULTURE IN SOME EGYPTIAN COASTAL LAGOON, IMPACTS AND POTENTIALS.

NAZIH B. AZER

The General Authority for Fish Resources Development (GAFRD), Egypt.¹

¹ Present adress: 4 El Tayaran st., Nasr City, Cairo Egypt

1. INTRODUCTION:

1-1- Characters and importance:

Coastal lagoons of Egypt constitute a major source of fish to the country. The unique environment with great diversity of ecosystems supported suitable habitat for fresh, brackish and marine species in one place.

Except for the hyper saline Bardaweel lagoon in Northern Sinai, all the other Egyptian coastal lagoons are sharing similar characters. This can be expressed in being all shallow, fresh to oligohaline brackish (0.8–2.5%o TDS²) in southern parts, brackish in most of the water body and sea water in northern areas. This is a result of the in flowing fresh water from the agriculture drains of the delta and the connection with the sea through several man made and natural passes and canals.

² Total Dissolved Solids.

1-2- Problems:

Although being of great importance for fish production, the northern lagoons of Egypt suffered several problems. Most of these problems are associated with the changes resulting from drying of large areas for agriculture use and the change in the characters of the water dynamics. These have resulted in reduction of the total area of lagoons and turning the great part of what is left into eutrophied fresh water bodies. To give an example of reduction in the area, Lake Manzala area was reduced from about 163,000 hectares in 1926 to only 76,000 hectares in 1994. The change in water quality was also clear in most of the lagoon where salinity was reduced from 16.7 ppt in 1926 to 2.9 ppt in 1982. Such changes affected dramatically the landed crop from the northern lagoons both in terms of tonnage or marketing value. The changes in the lagoons were also having a great negative socioeconomic impact on the native populations. Most of the population was supported economically by the lagoon based activities. These included mainly fisheries, boat building and repair, net and fishing gears manufacture, reed carpets and baskets, transport and other services. These activities are now reduced to a minimum.

1-3- An approach to solve the problem:

The GAFRD on the other hand, was after sustaining or even improving the fish production from these lagoons. This was not practically possible unless the fish production/available unit of lagoons' area is improved. The GAFRD approach was depending on implementation of aquaculture. Extensive, semi-extensive and semi-intensive forms were developed in such areas. Extensive fish farming, being basically known and practiced some way or another in the past by the natives is applied now in many areas in and around the lagoons. To develop such forms of extensive farming, improved forms were erected by the GAFRD to be used as pilot farms. One of such model fish farm is to be described here with some comparison with the traditional extensive fish farming models.

2- EXTENSIVE FISH FARMING:

2-1- The housha³ system, a tradetional models:

³ Local Arabic word used for an area surrounded by fences or dikes.

2-1-1 Construction:

The housha farming system is basically a group of variable sized (1–3 hectares) shallow ponds. These ponds are usually construced at the shallow nearshore water (depth, not more than 70 cm) by impounding the required area by dikes. This is usually done by excavating earth form the bottom, mixing it with straw (usually dry reeds or some times rice straw) and dumping it on top of each other to reach the required size. The dikes are not usually higher than 1 meter from the bottom and not wider than 1.5 meter. Ponds are usually connected to the lagoon either directly or through a canal that supply a group of ponds. This connection is usually through an opening of a special structure in the dike. The connection through these openings is a funnel like structure with its sides covered with wood or dry reeds, its wide end towards the lagoon and the narrow end can be covered by netting.

2-1-2- Stocking:

Housha system depends totally on the local stock of the lagoon for its supply with fish seeds. The behaviour of the local young fish species is known to the housha owners (usually fishermen), accordingly they attract fish into the ponds. Young mullets, eel and tilapia (main culture species in housha) are attracted by shallow water and currents. Depending on this, a water pump is fixed at the opening in the dyke and water is pumped to create a current in direction of the pond. This is usually done when young fish are observed in the shallow water near the housha. In some cases feed (mostly rice or wheat bran) is scattered on the water to attract fish. Attracted fish swim freely against the current though the funnel like openings to be trapped in the pond. This operation use to be done frequently and successively untill the owner feel that suitable seed stock is trapped. There is no control on numbers or species structure or on the presence of predator species.

2-1-3- Management

In most of the cases, production is depending totally on the natural productivity. In some cases, manuring is applied mostly by adding cattle manure to the bottom in limited (not more than 0.5 t/h) amounts. The housha system depends also on the recurrent filling and draining of the ponds by the rich water of the lagoons.

After the housha is filled with water and enough amounts of fish seeds, the system is usually left 4–6 months, then drained to the bottom. Fish are collected and the marketable size fish are sold and small size or low value fish are usually sun dried for fish meal. Such system produces 1.5–5 tones/h of marketable size fish/year. The variation in production level is due mainly to the richness of the site of the lagoon in which housha is built and to the experience and skill of owners.

The system although can be considered as a form of extensive fish farming is offering very high level of production. The system is also considered destructive to the natural resources of fish as sometimes large amounts of small fish are killed.

2-2- Pilot extensive farms:

This kind of farms is constructed mainly by the governmental authority as pilot unit for the natives.

This form is having some differences from the traditional housha system. Farms are usually of large area (up to 1000 hectares) with large ponds which some times may reach 100 hectares or more. Water depth is usually more than that in housha (up to 1 m) and dikes are larger and made with better engineering. The farm is usually divided into nursing and on growing ponds. Nursing ponds are usually smaller (2 hectares) and constructed inside the ongrowing ponds. Sluices with screens are controlling water inflow and outflow to the ponds and no system for trapping fish is applied.

Such kind of fish farms depends totally on stocking of fry and fingerlings brought from hatcheries and official collection stations. No fry or fish from the lagoon are used for stocking except for very few numbers of small size fry and larvae that may enter with in-flowing water. Stock structure and densities are controlled and usually calculated according to the estimated productivity of the farm. No feed or fertilizers are applied in the ongrowing ponds but nursing ponds are usually fertilized and some feed is supplied. Harvest usually occurs once a year after about 8 month of stocking ponds. Production of such kind of farms is usually in the range of 1.5–2.5 tones/hectare/year.

3-CONCLUSION:

Extensive fish farming is applied in and around the coastal lagoons of Egypt since more than five decades.

Different forms of traditional farming were applied and these are basically depending on the trapping of wild fish.

Traditional extensive farming in the lagoons reduces the number of fish available for fisheries in lagoon.

Traditional extensive fish farming can be destructive as many young fish are killed before reaching the marketable size.

Traditional fish farming facilitate production of fish from areas of lagoons becoming unsuitable for fisheries.

Traditional fish farming sustain some job opportunities for native population.

Modern extensive fish farming in lagoons can improve production and support the environment of the area.

NATIONAL REPORT OF GREECE

NATIONAL REPORT OF TURKEY

EAM Working Group Meeting on lagoon Management Montpellier - France 1995

There are 24 lagoons which are usually lakes formed by river barrage and river mouths along the Turkey coast.

Around 300 square kilometers water surface of these lagoons are exploited by using fish barrier with extensive method.

18 lagoons have fish barrier but a few of them set up at time. There are earth-ponds in the 4 lagoons. One of them is for shrimp culture with semi - intensive method. There are 3 hatch plants in the lagoons but one of them is a demonstration unit which located in Tuzla lagoon.

The total production in the lagoons is estimated around 1200–1500 tons.

TURKISH COASTAL LAGOONS

ACTIVITIES IN TURKISH LAGOONS