title: Fluoride content by ion chromatography using a suppressed conductivity detector and osmolality of bitterns discharged into the Pacific Ocean from a saltworks: feasible causal agents in the mortality of green turtles (Chelonia mydas) in the Ojo de Liebre lagoon, Baja California Sur, Mexico.
abstract: On December 1997, 94 corpses of green turtles, Chelonia mydas, were found at the Ojo de Liebre lagoon (OLL) adjacent to the industrial operation of Exportadora de Sal S. A (ESSA), the largest saltworks in the world, owned by the Mexican Government and Mitsubishi Corporation, located in Baja California Sur, Mexico. Every year about 551 x 10(6) m3 of seawater is solar evaporated, producing 7 x 10(6) tons of salt and 24.6 x 10(6) m3 of bitterns, the latter being discharged into the OLL, which is a costal lagoon of the Pacific Ocean. ESSA claimed that bitterns contain the same salts present in seawater, but 20-fold more concentrated than the former. Ion chromatography with a conductivity detector and ion suppression was used to determine the F-, Cl-, SO4(2-) and CO3(2-) contents of seawater, brines and bitterns collected at ESSA. Furthermore, the osmolality of brines and bitterns from ESSA was measured. F- content in bitterns was 60.5-fold more than that in seawater. The bitterns osmolality was 11,000 mosm/kg of water, whereas the turtle's plasma osmolality was about 400 mosm/kg of water. We concluded that the dumping of bitterns into the ocean should be avoided.
authors.affiliation: Center for Interdisciplinary Research on the Environment and Development, National Polytechnic Institute, México DF, México. lrtovar@avantel.net
authors.forename: Luis Raúl
authors.initials: LR
authors.lastname: Tovar
authors.forename: Ma Eugenia
authors.initials: ME
authors.lastname: Gutiérrez
authors.forename: Guillermo
authors.initials: G
authors.lastname: Cruz
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004553:Electric Conductivity; D019652:Extraction and Processing Industry / Q000592:standards*; D005459:Fluorides / Q000032:analysis* / Q000633:toxicity*; D008800:Mexico; D009994:Osmolar Concentration; D010140:Pacific Ocean; D012492:Salts; D012623:Seawater / Q000737:chemistry*; D014426:Turtles / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity
chemical_list: D012492:Salts; D014874:Water Pollutants, Chemical; C017082:brine; D005459:Fluorides