Comparison of sources and timing of primary production with implications for fisheries in five Gulf of Mexico estuaries.

Physical variables were related to the type, area, seasonal patterns and total productivity of estuarine systems across the Gulf of Mexico. Estuaries included in this analysis are: (1) Laguna Madre, Texas (2) Galveston Bay, Texas (3) Lake Pontchartrain, Louisiana, (4) Charlotte Harbor, Florida, and (5) Rookery Bay, Florida. All estuaries show seasonal patterns of sources and quantities of production related to physical variables of climate and hydrology. Mangroves and seagrasses dominate productivity in South Florida with peaks in late summer and early fall. Juncus marshes replace mangroves in north Florida changing to Spartina marshes in Louisiana and west Texas. Seagrasses and aquatic productivity dominate in Laguna Madre. Aquatic primary production rates are higher near river mouths (1-2 gC/m super (2)/day) declining towards the Gulf (0.1-0.7 gC/m super (2)/ day), but because of areal extent changes contribution to total productivity remains fairly constant.