Figure 5.

The cumulative distribution of the toxic dinoflagellate, Karenia brevis, on the West Florida shelf during 1957 to 1997, in relation to molar ratios of the total N/P stocks within 27 estuaries of the northern Gulf of Mexico [after Nordlie, 1990; Philips and Badylak, 1996; Turner and Rabalais, 1999; Rudnick et al., 1999]. When the river TDN/TDP ratios are less than 16, they are designated by open circles, with the numerals: (5) for Charlotte Harbor off the Peace River; (7) for Tampa Bay off Alafia River; (8) for Tampa Bay off Hillsborough River; and (9) for the Suwannee River. Areas identified as higher ratios than the Redfield one of 16 are instead indicated by open squares, with the numerals: (4) for San Carlos Bay off Caloosahatchee River; and (11) for the Apalachicola River. In other locations, number (1) designates eastern Florida Bay at the mouth of Taylor Slough; (2) western Florida Bay; (3) Ponce De Leon Bay off Shark River Slough; (6) Sarasota Bay; (10) Apalachee Bay; (12) Choctawhatchee Bay; (13) Pensacola Bay; (14) Perdido Bay; (15) Mobile Bay at the mouths of the Tombigbee and Alabama Rivers; (16) Mississippi Sound; (17) Mississippi River delta; (18) Atchafalaya Bay; (19) Calcasieu Lake off Calcasieu River; (20) Sabine Lake off Sabine River, (21) Galveston Bay off Trinity/San Jacinto Rivers; (22) Brazos River; (23) Matagorda Bay off Colorado River; (24) San Antonio Bay off Guadalupe River; (25) Aransas Bay; (26) Corpus Christi Bay off Nueces River; and (27) Laguna Madre, north of Rio Grande at Brownsville, TX. The large arrows denote epicenters of red tide initiation of K. brevis, within propitious physical and chemical habitats, off Florida and Texas.