A guide for planners and managers - IUCN

194 MARINE AND COASTAL
PROTECTED AREAS
Liquid Waste Disposal
Biological wastes may be sustainable under certain conditions and within carefully
determined limits.
Must be preceded by studies to determine amounts capable of being processed by
wetland communities.
Must be carefully regulated and monitored.
Must be accompanied by monitoring of shellfish for accumulation of toxins and
pathogens (e.g., hepatitis virus and cholera).
Navigation and Transport of Oil and Hazardous Chemicals
Must be carefully controlled and monitored.
Must be accompanied by oil spill contingency plan, including adequate containment
and cleanup equipment which is rapidly mobilized.
Must be permitted under license.
Introduction of Exotic Species
Should be generally discouraged, including accidental release.
Should be preceded by careful research.
May alter natural community succession and composition with undesirable effects
Conversion to Mariculture and Salt Production
Salt production and mariculture may be acceptable in bare saline areas (salinas) inland
from mangroves.
Mariculture has a mixed history of success and limited potential due to acidification
of soil.
May be more appropriate on small scale.
Loss of mangroves results in loss of natural shrimp and fish production.
Should be subject to comprehensive EIA and rigorous monitoring.
Salt marshes in many countries have been destroyed by using them as refuse
dumps. In Brazil solid wastes have been deposited at the rate of 130 tonnes per day
in the Hacorobi mangrove swamp (Saenger et al., 1983). Liquid waste in the form of
industrial and domestic sewage has destroyed wetlands in Puerto Rico, Guadeloupe,
and Martinique. Salt marshes and mangroves are able to process a certain amount
of these liquid wastes. According to E. P. Odum (1971), estuaries have varying abilities
to process degradable wastes, depending on their sizes, flow patterns, types, and climatic
zones. Certain materials (e.g., treated sewage and pulp mill wastes, seafood and food
processing wastes, petroleum wastes, and dredging spoil) can be decomposed and
dispersed provided that two conditions hold: (1) the system is not additionally stressed
by toxic pollutants, such as insecticides and acids; and (2) the rate of input is
controlled at acceptably low to moderate levels and the estuary is not suddenly
stressed by periodic dumping.
Impounding estuarine waters (i.e., cutting off their free connection with the open
sea) probably has a strong negative effect on their functioning, including their ability
to process waste and their value for food production (E. P. Odum, 1971).