312
F.J. Flores Verdugo et a!.
organisms, many of which are important fisheries resources (Flores-Verdugo et al. 1987). The extraction of freshwater has diminished to occurrence of brackish conditions in lagoons and increased the interstitial salinity in mangrove soils. As a consequence, highly productive ecosystems have
been transformed into little productive hypersaline systems with salt pans
(i.e., Huizache-Caimanero lagoon). Additionally, mangroves are sensitive
to changes in flooding periods. The opening of an artificial channel in the
Teacapan-Agua Brava complex altered the system from predominantly
freshwater-brackish to marine, causing the death of 24% (280 km 2 ) of the
white and black mangrove forests (Flores-Verdugo et al. 1997).
Pollution is caused by organochlorine pesticides which are added to
lagoon sediments (i.e., Carretas-Pereyra 120ng g- 1 ) from surrounding
agricultural lands (Rueda et al. 1997). Also, gold, silver, iron, and asbestos
mining as well as the introduction of polycyclic aromatic hydrocarbons
from oil refineries add to the degradation of productive coastal systems
(Botello et al. 1998).Along the entire coast valuable mangrove wetlands are
being transformed into marinas and hotels and shrimp aquaculture is
expanding, particularly in Sinaloa and Nayarit (94km 2 in 1993 to about
200km 2 in 1997; Paez-Osuna et al. 1997b). The discharge of shrimp pond
effluents is likely to impact coastal waters (i.e., Estero de Urias) by adding
elevated concentrations of nitrogen and phosphorus (Paez-Osuna et al.
1997a).
The detrimental impact of overfishing, wetland conversion, environmental degradation, disrespect for indigenous cultures, increasing development of tourism, etc. (Arriaga-Cabrera et al. 1998a) calls for an ecological management program which warrants sustainable use of natural
resources and nature conservation (Bojorquez 1993). However, lack of
information, strong economic pressure, and insufficient reinforcement
pose serious limitations for sound management despite the establishment
of a Ministry for the Environment, the requirement of environmental
impact assessments, and the creation of several biological reserves.
References
Arenas V, de Ia Lanza G (1981) The effect of dried and cracked sediments on the availability of phosphorous in coastal lagoons. Estuaries 4(3):206-212
Arriaga-Cabrera L, Vazquez-Dominguez E, Gonzalez-Cano J, Hernandez S, JimenezRosenberg R, Munoz-Lopez E, Aguilar-Sierra V ( 1998a) Regiones prioritarias marinas
de Mexico. Comision Nacional para el Conocimiento y Uso de Ia Biodiversidad (CONABIO/USAID/FMCN/WWF), Mexico, DF
F.J. Flores Verdugo et a!.
organisms, many of which are important fisheries resources (Flores-Verdugo et al. 1987). The extraction of freshwater has diminished to occurrence of brackish conditions in lagoons and increased the interstitial salinity in mangrove soils. As a consequence, highly productive ecosystems have
been transformed into little productive hypersaline systems with salt pans
(i.e., Huizache-Caimanero lagoon). Additionally, mangroves are sensitive
to changes in flooding periods. The opening of an artificial channel in the
Teacapan-Agua Brava complex altered the system from predominantly
freshwater-brackish to marine, causing the death of 24% (280 km 2 ) of the
white and black mangrove forests (Flores-Verdugo et al. 1997).
Pollution is caused by organochlorine pesticides which are added to
lagoon sediments (i.e., Carretas-Pereyra 120ng g- 1 ) from surrounding
agricultural lands (Rueda et al. 1997). Also, gold, silver, iron, and asbestos
mining as well as the introduction of polycyclic aromatic hydrocarbons
from oil refineries add to the degradation of productive coastal systems
(Botello et al. 1998).Along the entire coast valuable mangrove wetlands are
being transformed into marinas and hotels and shrimp aquaculture is
expanding, particularly in Sinaloa and Nayarit (94km 2 in 1993 to about
200km 2 in 1997; Paez-Osuna et al. 1997b). The discharge of shrimp pond
effluents is likely to impact coastal waters (i.e., Estero de Urias) by adding
elevated concentrations of nitrogen and phosphorus (Paez-Osuna et al.
1997a).
The detrimental impact of overfishing, wetland conversion, environmental degradation, disrespect for indigenous cultures, increasing development of tourism, etc. (Arriaga-Cabrera et al. 1998a) calls for an ecological management program which warrants sustainable use of natural
resources and nature conservation (Bojorquez 1993). However, lack of
information, strong economic pressure, and insufficient reinforcement
pose serious limitations for sound management despite the establishment
of a Ministry for the Environment, the requirement of environmental
impact assessments, and the creation of several biological reserves.
References
Arenas V, de Ia Lanza G (1981) The effect of dried and cracked sediments on the availability of phosphorous in coastal lagoons. Estuaries 4(3):206-212
Arriaga-Cabrera L, Vazquez-Dominguez E, Gonzalez-Cano J, Hernandez S, JimenezRosenberg R, Munoz-Lopez E, Aguilar-Sierra V ( 1998a) Regiones prioritarias marinas
de Mexico. Comision Nacional para el Conocimiento y Uso de Ia Biodiversidad (CONABIO/USAID/FMCN/WWF), Mexico, DF