The Coastal Lagoon Cienaga Grande de Santa Marta, Colombia
43
that the total catch and its composition vary between years (Fig. 2.3). Between 1993 and 1996, the total annual catch has decreased from 6,286 to
4,870 tons, of which about 82% were fishes, 10% oystera (C. rhiz ophorae),
4 o/o shrimp (Penaeus spp.), 3% conch (M. melongena), and 0.5% swimming crabs ( Callinectes bocourti, C. sapidus). Catches of species like Oligoplites saurus, 0. palo meta, Bairdiella ronchus, and Diapterus spp., and juveniles of E. saurus and T. atalanticus, that previously were not exploited,
have become more important. Fisheries of introduced exotic species like
Tilapia ( Oreochromis cf. nilotica; up to 37 tons), freshwater species ( Caquetaia kraussi; 132 tons), and Prochilodus magdalenae (97 tons) seem to grow
continuously (Santos-Martinez and Viloria 1998). Recent studies by Instituto de Investigaciones Marinas y Costeras de Punta Betin "Jose Benito
Vives de Andreis" (INVEMAR) show that a healthy CGSM ecosystem could
support a fishery production of about 10 x 10 3 tons year- 1 if current levels
of fishing technology and intensity were applied.
2.6
Management
The degradation of the Magdalena River delta and the CGSM ecosystem
had severe economic implications, not only for the region but also for
the entire country. Consequently, the Colombian government established
policies to improve wastewater treatment and regulate fisheries among fishing and coastal villages. Furthermore, recent changes in the national
constitution have given a local environmental agency (CORPAMAG)
greater authority over CGSM issues. This agency, together with technical
cooperation of the Colombian-German PRO-CIENAGA project, INVEMAR, and financial support from the Inter-American Development Bank,
is developing a restoration program for the hydrologic regime of the
CGSM, hoping to reach a point where the natural and assisted regeneration
of mangrove forests will become viable. The diversion of the Magdalena
River to its former course and the reopening of three original natural
channels will eventually introduce a maximum total freshwater flow of
approximately 150m 3 s- 1 into the CGSM. One of these channels adds freshwater (20m 3 s- 1 ) to the northern part of the system since 1996, while the
other two channels (about 100m 3 s- 1 ) were opened recently. Since the
salinity regime in the lagoon is a function of freshwater runoff and water
exchange through the inlet, the restoration program also contemplates the
construction of box-culverts at the Barrier Island (Isla de Salamanca) to
increase water exchange between the lagoon and the sea. Ecological baseline assessments of the CGSM, to evaluate the effectiveness of the ongoing
43
that the total catch and its composition vary between years (Fig. 2.3). Between 1993 and 1996, the total annual catch has decreased from 6,286 to
4,870 tons, of which about 82% were fishes, 10% oystera (C. rhiz ophorae),
4 o/o shrimp (Penaeus spp.), 3% conch (M. melongena), and 0.5% swimming crabs ( Callinectes bocourti, C. sapidus). Catches of species like Oligoplites saurus, 0. palo meta, Bairdiella ronchus, and Diapterus spp., and juveniles of E. saurus and T. atalanticus, that previously were not exploited,
have become more important. Fisheries of introduced exotic species like
Tilapia ( Oreochromis cf. nilotica; up to 37 tons), freshwater species ( Caquetaia kraussi; 132 tons), and Prochilodus magdalenae (97 tons) seem to grow
continuously (Santos-Martinez and Viloria 1998). Recent studies by Instituto de Investigaciones Marinas y Costeras de Punta Betin "Jose Benito
Vives de Andreis" (INVEMAR) show that a healthy CGSM ecosystem could
support a fishery production of about 10 x 10 3 tons year- 1 if current levels
of fishing technology and intensity were applied.
2.6
Management
The degradation of the Magdalena River delta and the CGSM ecosystem
had severe economic implications, not only for the region but also for
the entire country. Consequently, the Colombian government established
policies to improve wastewater treatment and regulate fisheries among fishing and coastal villages. Furthermore, recent changes in the national
constitution have given a local environmental agency (CORPAMAG)
greater authority over CGSM issues. This agency, together with technical
cooperation of the Colombian-German PRO-CIENAGA project, INVEMAR, and financial support from the Inter-American Development Bank,
is developing a restoration program for the hydrologic regime of the
CGSM, hoping to reach a point where the natural and assisted regeneration
of mangrove forests will become viable. The diversion of the Magdalena
River to its former course and the reopening of three original natural
channels will eventually introduce a maximum total freshwater flow of
approximately 150m 3 s- 1 into the CGSM. One of these channels adds freshwater (20m 3 s- 1 ) to the northern part of the system since 1996, while the
other two channels (about 100m 3 s- 1 ) were opened recently. Since the
salinity regime in the lagoon is a function of freshwater runoff and water
exchange through the inlet, the restoration program also contemplates the
construction of box-culverts at the Barrier Island (Isla de Salamanca) to
increase water exchange between the lagoon and the sea. Ecological baseline assessments of the CGSM, to evaluate the effectiveness of the ongoing