The tropical Eastern Pacific Ocean (EPO) is an area off the coasts of Central and South America, covering 2 million square kilometers (770,000 square miles). This region is influenced by numerous oceanographic processes. In general, large numbers of Mobula rays are often seen this region because of the tropical sea surface temperature and the high abundance of phytoplankton making this region an ideal habitat for these species.
Several subpopulations appear to have decreased in Mexico as a result of sustained pressure from different forms of fishing, such as trawling, longline and purse seine. The increase in catches in the eastern Pacific Ocean is cause for concern.
STUDY AREA
Eastern Tropical Pacific
Our study area encompasses the fishing grounds of the purse-seine fleet operating in the eastern Pacific Ocean (20°S-30°N and 70°-150°W). This area includes several productive systems characterized by frequent upwelling events. The equatorial upwelling takes place along a longitudinal gradient North and South of the Equator characterized by cold waters and high concentrations of nutrients. In addition, other oceanographic processes, such as the Costa Rica Dome and the coastal upwellings generated by seasonal wind jets along Mexico and Central America concentrate large amounts of nutrients and influence the abundance and distribution of marine organisms.
Baja California Peninsula
Baja California Peninsula stretches along the Pacific Ocean on its west coast, where the cold and productive Current of California make this coast rich in nutrients all year long. On the east side of the Penninsula, the Gulf of California, also known as the Sea of Cortez, runs along 1,120 km (700 miles) between Baja California and mainland Mexico. With more than 900 islands, the Gulf of California is notable as a region of special biological significance due to its great habitat diversity. Because of that, the Gulf of California was declared an UNESCO World Heritage Site in 2005 with more than 800 species of fish, 2000 species of invertebrates, 48 species of sharks, and 5 mobula species in addition to marine mammals like sea lions, whales, and dolphins.
However, the Gulf of California is subjected to 70% of Mexican fisheries with less than 1% of its surface being protected as «no-take» areas.
Photographer: @tonidebaja