21 Upwelling and Lagoonal Ecosystems
of the Dry Pacific Coast of Baja California
S.E. IBARRA-0BANDO, V.F. CAMACHO-IBAR, J.D. CARRIQUIRY,
and S.V. SMITH
21.1 Introduction
Baja California, between 32°30'N, ll7°W and 23°N, ll0°W, is a 1300-kmlong and 30- to 240-km-wide peninsula, which is flanked by the Pacific
Ocean in the west and the Gulf of California in the east. The continental
shelf along the Pacific coast of Alta and Baja California (42-22.9°N) is typically narrow (usually <20km) but widens to 50-70km in the central and
southern embayments. The coastal geomorphology is composed of faultline, dunes, elevated wave-cut benches, barrier beaches, islands, spits, and
bay barrier coasts. Numerous and extensive, mainly sandy plains and valleys occur along the coast, and muddy marsh flats can be found at the
mouth of the streams. Coastal lagoons and estuaries represent a small part
of the coastline and are partially protected by bay-mouth sand spits (Wiggins 1980).
In general, the Baja Californian coast can be divided in three latitudinal
regions based on coastal geomorphology and offshore and inshore regions
delimited by the edge of the continental shelf (200m depth). The northern
third comprises the region between Bahia de Todos Santos (31°30'N) and
Bahia Sebastian Vizcaino (27°30'N), and represents an extension from the
Southern California Bight. The region in the middle third includes two
important upwelling areas, Punta Eugenia and Punta Abreojos, which
represent the typical upwelling ecosystem of Baja California. The region in
the southern third, centered in Bahia Magdalena, has been described as the
region with the strongest latitudinal gradient in physical and chemical
variables, and is considered as a subtropical-tropical interface.
Ecological Studies, Vol.l44
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
©Springer-Verlag Berlin Heidelberg 2001
of the Dry Pacific Coast of Baja California
S.E. IBARRA-0BANDO, V.F. CAMACHO-IBAR, J.D. CARRIQUIRY,
and S.V. SMITH
21.1 Introduction
Baja California, between 32°30'N, ll7°W and 23°N, ll0°W, is a 1300-kmlong and 30- to 240-km-wide peninsula, which is flanked by the Pacific
Ocean in the west and the Gulf of California in the east. The continental
shelf along the Pacific coast of Alta and Baja California (42-22.9°N) is typically narrow (usually <20km) but widens to 50-70km in the central and
southern embayments. The coastal geomorphology is composed of faultline, dunes, elevated wave-cut benches, barrier beaches, islands, spits, and
bay barrier coasts. Numerous and extensive, mainly sandy plains and valleys occur along the coast, and muddy marsh flats can be found at the
mouth of the streams. Coastal lagoons and estuaries represent a small part
of the coastline and are partially protected by bay-mouth sand spits (Wiggins 1980).
In general, the Baja Californian coast can be divided in three latitudinal
regions based on coastal geomorphology and offshore and inshore regions
delimited by the edge of the continental shelf (200m depth). The northern
third comprises the region between Bahia de Todos Santos (31°30'N) and
Bahia Sebastian Vizcaino (27°30'N), and represents an extension from the
Southern California Bight. The region in the middle third includes two
important upwelling areas, Punta Eugenia and Punta Abreojos, which
represent the typical upwelling ecosystem of Baja California. The region in
the southern third, centered in Bahia Magdalena, has been described as the
region with the strongest latitudinal gradient in physical and chemical
variables, and is considered as a subtropical-tropical interface.
Ecological Studies, Vol.l44
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
©Springer-Verlag Berlin Heidelberg 2001