A. Case Studies Relating to Industrial and Urban Development in the Coastal Zone Industrial Development at Point Lisas, Trinidad. This case study shows how changes upstream and in the adjoining coastal lands had serious ecological and sociological impacts on the beach/mangrove zone and the offshore zone. These adverse impacts could have been lessened or removed completely had an Environmental Impact Assessment been conducted and its recommendations implemented by an effective agency. In Trinidad the west coast is the most environmentally stressed coastal area, over 88% of the population live in this area and it employs 93% of the labor force. This case study deals with an industrial estate on the west coast at Point Lisas. Prior to the industrial estate the area was marginal sugar cane land with fringing mangroves along the coast. In 1966 the Point Lisas Industrial Port Development Corporation was established, the Govemment acquired majority shares in this company. A study by McShine (1985) listed the industries located on the estate as : iron and steel, fertilizers, urea, methano l and a power station. In 1978 the Govemment identified Point Lisas as a priority area for housing. As a result of these developments a decision was taken to divert the Couva River into Carli Bay, see Figure 1. This was designed primarily to: (a)Improve the drainage from the new housing area and industrial estate and to accommodate the increased runoff; (b) Accommodate large volumes of hot water to be released from the power station, fertilizer and methanol plants; (c) To increase the water circulation in Carli and Couva Bays so that the water temperature at the cooling water intake site in Couva Bay would not be increased. By 1985 a new dredged channel into Carli Bay had been completed, however, this had not been joined to the river. Initially the dredge spoil was dumped in the Bay, however, this caused siltation problems in the dredged channel so the spoil was dumped betw een the original river channel and the dredged channel. In addition a dam was built near the proposed housing development, the proposed lake would be used as a recreational area for the housing development, and as a reservoir for an emergency water suppl y to the industrial estate. The resulting ecological impacts are as follows: (a) The dredging of the new river mouth and channel has resulted in the loss of benthic habitats in Carli Bay which has led to a decline in the number of commercially important fish and shrimp. The dredging and dumping of the spoil has destroyed some 15 hectares of wetlands with the subsequent loss of oysters, mussels and edible land crabs. (b) The construction of the dam on the Couva River has led to the accumulation of untreated sugar factory wastes in the lake. It has also formed a barrier that will hinder animals that need to migrate from fresh water to the sea (or vice versa) for breed ing purposes. The resulting sociological impacts are as follows: (a) The complete abandonment of the commercial shell fish trade. (b) The construction activities have caused siltation of some of the natural drainage channels leading to stagnant water conditions. (c) The untreated sugar waste in the lake means that it cannot serve its recreational or emergency reservoir functions. Additional ecological and sociological impacts were anticipated if the new channel was joined to the river. These included the drying out of the lower reaches of the Couva River thereby depleting the commercially important mussel beds, and the loss of ro ad access to fishing facilities and the only sandy beach in the area. McShine (1985) recommended that the new cut should not be made. Case Study Assessment: The development described in this case study was partly in the coastal zone and partly upstream of the coastal zone. The industrial estate itself lies in the coastal zone. The housing estate and the sugar factory lie upstream, the housing estate some 1.5 km from the beach zone. This case study has described the impact of one small aspect of these developments, namely the river mouth diversion. Obviously the total impact of the industrial and housing estates on the coastal zone will be far greater. The river diversion has resulted in the loss of habitat in the beach/mangrove zone and in the ofshore zone thereb y resulting in the destruction of a viable fishing industry. One aim of the project, to provide a lake-reservoir, cannot be fulfilled due to pollution. In addition it appears that the cut joining the new channel to the existing river may not be made due to changes in the industrial and housing components of the project and a setback in the project funding. Thus the damage to the coastal environment may have been for nothing. Much of the environmental damage is irreversible. For example the loss of the benthic habitat and the decline of the fish and shrimp industry is a long term effect of the dumping of the dredge spoil which will continue to result in high siltation for man y years to come. Similarly the loss of wetlands results in the loss of habitat for oysters, mussels and crabs, again, this is irreversible. The construction of the dam and the creation of the polluted lake could be reversed if the wastes from the sugar factory were treated, this would obviously have an associated cost factor. Similarly the dam could be modified to allow fish migration up and down stream. Thus with this case study some of the damage could be reversed at a cost. As the case study showe d, additional damages would result if the new channel was joined to the river. Most of the environmental damage could have been reduced or eliminated had an environmental impact assessment (EIA) been conducted prior to the project. These impacts could have been predicted. Unfortunately no EIA was carried out. As a follow up to this case study, some furher work was done on the economic aspects of the Point Lisas Industrial Estate, Manwaring and McShine (1989). This study analyses the impact of the change in land use from agriculture and fishing to a heavy ind ustrial estate, port and urban development. The Government invested over US$ 1.3 billion in the estate. An EIA should have been mandatory for a project of this size. Manwaring & McShine went on to analyze the benefits and costs to the economy of Trinid ad and Tobago derived from the Estate. Using the Net Present Value Method, they showed that from a financial and economic point of view, the Government investment over a fifteen year time period, will result in net negative returns to the economy. They conclude that the economic benefits would have increased if a comprehensive EIA had been carried out. References: Manwaring, G., McShine, H. 1989. Economic Aspects of the Point Lisas Case Study. Conference on Economics and the Environment, Barbados 1989, Caribbean Conservation Association. McShine-Mutunhu, H. 1985. Couva River Diversion - A Problem in Environmental Planning. Proceedings of the Caribbean Seminar on Environmental Impact Assessment, Barbados 1985, Caribbean Conservation Association.