Secondary Productivity of Mollusks in Mangrove Estuaries of Ensenada de La Paz, Baja California Sur, Mexico
Esteban F. Félix-Pico, Mauricio Ramírez-Rodríguez, and Jorge A. López-Rocha
Abstract.—To measure secondary productivity of mangrove systems, we estimated the abundance (individuals/m2) and mass increment (g/month) of the two bivalve species: the black ark Anadara tuberculosa and palmate oyster Saccostrea palmula. Mass increments were based on individual growth rates derived from length-frequency distributions analyses. Samples were collected at three mangrove estuaries in a sand barrier at Ensenada de La Paz from August 2007 to July 2009. The average abundance was 1.27 individuals/m2 for black ark and 510 individuals/m2 for palmate oysters. Estimated growth rates were 3.67 g/month for black ark and 0.18 g/month for palmate oysters. The average secondary productivity of the black ark was 4.51 g•m-2•month-1 and peaked during the spring, while for the palmate oyster Saccostrea palmula it was 97.9 g•m-2•month-1, with peak productivity recorded during the summer. The findings of this investigation constitute a necessary element for establishing a baseline to evaluate the consequences of the various natural and anthropogenic pressures that the mangrove systems of El Mogote of La Paz Bay, Baja California Sur, Mexico.