INTRODUCTION

With the aim of demonstrating environmental accountability, setting a good example to other industries and replenishing dwindling fish reserves in regional waters, the company embarked on constructing a fish farm close to the sea water outlet in November 1996. Since then, more than 1 million sea breams (rare species) have been released into the sea. To demonstrate that even while operating a sophisticated petrochemical complex it is necessary to care for the environment, GPIC has constructed a fish farm on the South side of the GPIC complex. Different kinds of fish are being reared and bred here so that their growth can take place in a congenial atmosphere. It is also desire of GPIC management to ensure that some of the fish harvested goes to charity for the underprivileged.

FISH FARMING

"Fish Farming" means growing fish held in tanks, cage or pond. GPIC Fish Farm is of an enclosure type, made of steel, rocks, wood and synthetic materials, with a total surface area of 2,225 square meters. It is unique because it is part of the natural sea surrounding the complex.

A variety of fish were chosen, the majority of which were Black Sea Bream (Shim) and a few Mullet (Meid) and Rabbit fish (Saffee) were kept (cultured). All of these are famous tropical fish to be found in Bahrain's waters.

PROJECT PROFILE

Description

This project is experimental and involves the culture of known species of fish in a fixed enclosure, exposed to all natural climatic conditions for a considerable length of time, particularly from the month of November to July.

BASIC CONSIDERATIONS

TECHNICAL ASPECT

A. Site selection/Location

  1. Circulation- The area has sufficient exchange of water through the enclosure with current velocity ranging from 10-60 cm/sec. The spring tide moves towards the Southern portion, whereas low tide current moves in the opposite direction. There is an approximate gap of 30minutes during dead current.
  2. Dissolved Oxygen- Since water in the surrounding area is tide dependent, the spring tide fluctuation (which tends to renew 100% of the total volume of water every now and then) prompts a continuous and steady supply of Oxygen evenly maintained at its optimum level> 5ppm, essentially important in the role of aqua culture.
  3. Water medium- Seawater in the vicinity has a salinity range of 49000 ppm.
  4. Temperature- Often been observed during the last part of the winter when low tide goes to its lowest minimum level, the temperature drops to almost 12 Degree C. In summer sea- water temperature sometime rises to its critical level of 37 Deg C.
  5. pH level- Different types of fish have their own pH value to suit. Through experience (Shim) thrive mostly in alkaline water. Seawater around GPIC fish farm has a pH of 8.2 to 8.5 respectively.
  6. Wind and Wave protection- Though the fish farm has a minimum depth of nearly 2.5 meters during high tide and 1.5 meters during low tide, wind disturbance which creates waves, usually does not happen when an incoming wind is from the North, West or South direction due to the land mass formation that blocks its way and serves as a barrier. An Easterly wind is the only one that causes disturbing to the farm environment.

B. Live Fish Handling / Fish Husbandry.

The cultured fish (Shim) spent most of their early life in the Mari culture Ministry, from hatching as eggs, larvae, post larvae until they reached the juvenile stage (approx.70grams body weight) when they were brought to the GPIC fish farm. They later spent the rest of their growing period in the enclosure until reaching an average of 210 grams body weight, over a total of 223 days of growth.

C. Stock density.

The reported total population was 4,375 fish, which is stocking density of 7 pieces/m3. The expected target yield is very good due to the successful survival rate.

D. Feed and feeding rate.

The supplement diet for Shim fish was mainly compound dry food in pellet form. Sometimes they were given wet food such as fish or crabmeat if available. The feeding rate ranges from 3-7% of body weight to the corresponding biomass. The total food amount was then given four times daily, depending on the current, climatic and thermal conditions, with regard to the fish appetite and eating habits.

E. Monitoring/ Sampling.

It is most important to keep records of fish growth to show whether the cultured stock is growing properly. Any indication or sign of lethargy means something is wrong. A simple parameter is useful.

In the GPIC fish farm the average body weight of the cultured stock was checked at 15 days intervals. Throughout the culture period which lasted 223 days, the greatest growth so far was attained during the months of December and January when the maximum average temperature recorded was 23 Degree C.

F. Maintenance.

Daily routine check-ups were being conducted, as well as diving for submerged physical structure inspection. Cleaning and brushing net of fouling organisms, especially overgrowths of marine anemones like barnacles, which can cause net breakage. Any damage was immediately attended to avoid the fish escaping.

G. Fish diseases / Hygiene

Disease is an abnormal and physically damaging condition caused by changes within an animal's body. It may be a direct result from any of the following infections: Bacterial or viral, parasites, injury, toxic chemicals, algal blooms or deficiencies and toxins in the diet. Stocking density in the enclosure in which they are vulnerable and cannot escape causes much of the disease risk to cultured fish.

Fish in the GPIC charity so far have not encountered any epizootic outbreak or large mortalities caused by chemical or algal poisoning. Although there were some minor cases of fish kill as a result of injury during fish transfer and fish trap on the netting. Medical application was never conducted whatsoever in any means prophylactic or therapeutic.

H. Harvesting

Since the farm has uneven bottom surfaces, scattered rock and dead corals, it is difficult the stock by means of a dragnet or sieving, unless all these materials are removed. An alternative way to catch them is by means of "Gill net". This method however, is not totally effective as it allows only a selective catch, the remainder being released back to the sea.