Summary
349
tive tsunamis in response to earthquakes around the rim of the Pacific
basin. The Atlantic coast between the Rio de la Plata estuary and Recife,
Brazil, is dominated by east coast swells from the south or southeast,
whereas the coast north of Recife mainly experiences swells from the north
and northeast. Tropical cyclones (hurricanes in the Caribbean and
cyclones in the western Pacific) generate high and destructive waves several times annually to Caribbean shores and the Pacific coast of Mexico.
Because of global warming during the past century, sea level has been
rising eustatically approximately 1.2 mm year- 1 • However, the relative sea
level depends not only on the change in global sea level but also on regional and local changes in land elevation and oceanographic, atmospheric,
and hydrological conditions (Stewart et al. 1990). Relative sea levels along
both east and west coasts of South America have in the past few decades
been rising ever so slowly. Relative sea level change along the west coast
has varied locally depending on uplift and slumping associated with geotectonics of the Cordilleras and plate subduction below the Pacific margin
(see chapter by Kellogg and Mohriak). The east coast, on the other hand,
has experienced a relative sea level fall of 3-7m in the past 5,500 years (Isla
1989; Martin and Dominguez 1994; Gomez and Perillo 1995; Angulo and
Lessa 1997; Lanfredi et al. 1998).
5 Human Impacts
The exponential increase of the human population in the past century is
seriously impacting the global climate and coastal marine ecosystems. In
1996, Latin America and the Caribbean had a total population of 486 million, or 8.4 o/o of the global population compared to 12 o/o of the global land
area. Although the population density for the continent is less than the global average, the doubling time for the population is 39 years (Population
Reference Bureau 1996). The exploitation of habitats/resources is a function of human population size and density, generally being many times
greater at the coast, and the population's level of socio-economic development. As a consequence, some of the highly productive coastal and marine
ecosystems in South and Central America are subjected to high levels of
anthropogenic impact.
Large coastal bays and gulfs, which for most parts have formed as a
result of tectonic activity, are common features of South America's coasts.
The Gulf of Guayaquil in Ecuador (see Chap. 17 by Twilley et al.) is the
largest inland coastal marine system on the Pacific coast. Both Bahia de
Buenaventura, Colombia (see Chap. 18 by Cantera and Blanco), and Baia de
349
tive tsunamis in response to earthquakes around the rim of the Pacific
basin. The Atlantic coast between the Rio de la Plata estuary and Recife,
Brazil, is dominated by east coast swells from the south or southeast,
whereas the coast north of Recife mainly experiences swells from the north
and northeast. Tropical cyclones (hurricanes in the Caribbean and
cyclones in the western Pacific) generate high and destructive waves several times annually to Caribbean shores and the Pacific coast of Mexico.
Because of global warming during the past century, sea level has been
rising eustatically approximately 1.2 mm year- 1 • However, the relative sea
level depends not only on the change in global sea level but also on regional and local changes in land elevation and oceanographic, atmospheric,
and hydrological conditions (Stewart et al. 1990). Relative sea levels along
both east and west coasts of South America have in the past few decades
been rising ever so slowly. Relative sea level change along the west coast
has varied locally depending on uplift and slumping associated with geotectonics of the Cordilleras and plate subduction below the Pacific margin
(see chapter by Kellogg and Mohriak). The east coast, on the other hand,
has experienced a relative sea level fall of 3-7m in the past 5,500 years (Isla
1989; Martin and Dominguez 1994; Gomez and Perillo 1995; Angulo and
Lessa 1997; Lanfredi et al. 1998).
5 Human Impacts
The exponential increase of the human population in the past century is
seriously impacting the global climate and coastal marine ecosystems. In
1996, Latin America and the Caribbean had a total population of 486 million, or 8.4 o/o of the global population compared to 12 o/o of the global land
area. Although the population density for the continent is less than the global average, the doubling time for the population is 39 years (Population
Reference Bureau 1996). The exploitation of habitats/resources is a function of human population size and density, generally being many times
greater at the coast, and the population's level of socio-economic development. As a consequence, some of the highly productive coastal and marine
ecosystems in South and Central America are subjected to high levels of
anthropogenic impact.
Large coastal bays and gulfs, which for most parts have formed as a
result of tectonic activity, are common features of South America's coasts.
The Gulf of Guayaquil in Ecuador (see Chap. 17 by Twilley et al.) is the
largest inland coastal marine system on the Pacific coast. Both Bahia de
Buenaventura, Colombia (see Chap. 18 by Cantera and Blanco), and Baia de