CHAPTER 13 • Coastal Zone Management: Issues and Initiatives in Small South Asian Nations 249
13.5.2.3
Aquaculture
The development of pond aquaculture has been encouraged by the Sri Lankan government in the last decade by initiating various incentive schemes. Most of the shrimp
culture sites are located in the northwestern coastal belt of the island. The impacts of
this development activity are:
• Increased concentration of nutrients;
• Production of toxic metabolites such as ammonia, hydrogen sulfides etc.;
• Increase in suspended solids;
• Land salinization;
• Soil tmd water acidification;
• Natural wetlands siltation and
• Changes in coastal land use.
13.5.2.4
Siltation
The reclamation of coastal flats and flood plains was previously a common practice in
Sri Lanka, which have now been suspended Heavy siltation is caused by the clearing of
forests and encroachment of river banks. Most of the estuaries and lagoons are in fact very
shallow due to the high sedimentation. Another result of sedimentation is the formation
of sand bars across the sea outlets of the coastal water bodies. This reduces the exchange
with the sea and sand bars are formed as a result. In addition, the shrimp and fish recruitment is restricted due to these sand bars. Extraction of sand from the lower reaches
of the river beds during the dry season causes sea water intrusion. In the flood season,
trapping of bed load materials occurs in places where sand has been extracted. The
loss of sediments affeats coastal sand replenishment. However, this activity is now regulated and coastal sand mining is prohibited under the Coastal Conservation Act.
13.5.2.5
Tourism
Most of the tourist resort areas are distributed along the coastal zone of the island. The
construction of hotels and resorts, has caused occasional erosion of beaches. These
hotels have also cleared natural vegetation in some areas. There has also been discharge
of sewage and waste water into the water bodies without proper treatment.
Information on marine environmental research in Sri Lanka is extremely scarce and
research carried out in nearshore waters has not been aimed at studying the pollution
hazards. Pollution problems affecting co~stal and inland waters are widespread in
Sri Lanka. Lunawa lagoon, Walawe Ganga,Velachchenai lagoon represent classic examples of the impact of organic waste and nutrient enrichment causing fish kills. The
most significant negative impact faced by the marine environment however, comes from
industrial pollution; proper measures must clearly be taken to curb the degradation
of the marine ecosystem.
13.5.2.3
Aquaculture
The development of pond aquaculture has been encouraged by the Sri Lankan government in the last decade by initiating various incentive schemes. Most of the shrimp
culture sites are located in the northwestern coastal belt of the island. The impacts of
this development activity are:
• Increased concentration of nutrients;
• Production of toxic metabolites such as ammonia, hydrogen sulfides etc.;
• Increase in suspended solids;
• Land salinization;
• Soil tmd water acidification;
• Natural wetlands siltation and
• Changes in coastal land use.
13.5.2.4
Siltation
The reclamation of coastal flats and flood plains was previously a common practice in
Sri Lanka, which have now been suspended Heavy siltation is caused by the clearing of
forests and encroachment of river banks. Most of the estuaries and lagoons are in fact very
shallow due to the high sedimentation. Another result of sedimentation is the formation
of sand bars across the sea outlets of the coastal water bodies. This reduces the exchange
with the sea and sand bars are formed as a result. In addition, the shrimp and fish recruitment is restricted due to these sand bars. Extraction of sand from the lower reaches
of the river beds during the dry season causes sea water intrusion. In the flood season,
trapping of bed load materials occurs in places where sand has been extracted. The
loss of sediments affeats coastal sand replenishment. However, this activity is now regulated and coastal sand mining is prohibited under the Coastal Conservation Act.
13.5.2.5
Tourism
Most of the tourist resort areas are distributed along the coastal zone of the island. The
construction of hotels and resorts, has caused occasional erosion of beaches. These
hotels have also cleared natural vegetation in some areas. There has also been discharge
of sewage and waste water into the water bodies without proper treatment.
Information on marine environmental research in Sri Lanka is extremely scarce and
research carried out in nearshore waters has not been aimed at studying the pollution
hazards. Pollution problems affecting co~stal and inland waters are widespread in
Sri Lanka. Lunawa lagoon, Walawe Ganga,Velachchenai lagoon represent classic examples of the impact of organic waste and nutrient enrichment causing fish kills. The
most significant negative impact faced by the marine environment however, comes from
industrial pollution; proper measures must clearly be taken to curb the degradation
of the marine ecosystem.