Ecology, conservation and human history of marine mammals in the Gulf of California and Pacific coast of Baja California, Mexico
In total, 43 marine mammal species, eight of which are threatened, inhabit the Gulf of California and Pacific coast of Baja California. The unique attributes of marine mammal fauna such as species richness, risk condition, energy consumption and calving in this region are historically and geographically important. Marine mammals in the Baja California seas have been hunted for the past 10,000 years and they are also currently subject to severe anthropogenic impacts. Commercial hunting started in the late 18th century and some populations declined until the 1970s. Anthropogenic impacts on marine mammals diversified during the 20th century, with fisheries and pollution now being their greatest threats. Currently, the coasts surrounding Baja California seas are home to 3.06% of Mexican people and 1.77% live in relation with maritime activities. This is a relatively small population that has been growing since the Spanish conquest in the 16th century together with decimation of the regional indigenous populations. The scarce people around Baja California seas have important contributions to Mexican economy and marine disturbance, mostly because the arid environments of northwestern Mexico have historically encouraged marine fisheries as the major intake of natural living resources in the region. Therefore, the region's environmental problems do not stem from an overpopulation requiring ecosystem services, with the exception that exhaustion of the underground aquifers is of great concern, but from historical problems related with social and economic development. Conservation of marine mammals in the Baja California seas may be helpful to geographically and socially integrate human development and ecosystem protection, to address current problems of illegality, sectorial conflicts and partiality in conservation actions as well as to monitor the modifications and functionality of the marine ecosystem.