RESUMEN
The Wider Caribbean Region is an important tourist destination where agricultural, industrial and shipping activities are also carried on. Coastal zones are heavily populated and receive a high human pressure; however, few monitoring programmes allow assessing long-term anthropogenic impact trends in these areas, which are especially useful for integrated management programs. Through the support of the International Atomic Energy Agency (project RLA/7/012), sediment core activities of 210Pb and 137Cs were used to evaluate changes in sedimentation rates in 11 relevant coastal areas of the region, where environmental information is scarce, but needed to support national environmental policies. Most 210Pb activity profiles were atypical, attributed to non-steady sedimentation conditions; whereas 137Cs activity profiles, showing very low values, were of little help for 210Pb-dating corroboration. Results evidenced conspicuous changes in mass accumulation rates (MAR), specially through the Anthropocene (i.e. since ~1950s) in most cases, attributed to deforestation and land erosion (one of the clearest indicators of global change), and the input of urban and industrial untreated wastes. The recent MAR decrease in Havana Bay (Cuba) was attributed to the implementation of environmental policies, which showed that 210Pb-derived reconstruction of environmental changes is also useful to verify the effectiveness of management programs to control land-derived erosion and siltation issues. Since siltation can be detrimental to valuable coastal resources around the world, retrospective evaluations of sedimentation rates, based on 210Pb-dated cores, are highly recommended to assist integrated coastal zone management programs in the region and elsewhere.
Asunto(s)
Monitoreo de Radiación , Cuba , Monitoreo del Ambiente , Sedimentos Geológicos , Plomo , Radioisótopos de Plomo/análisis , Estudios Retrospectivos , Contaminantes Químicos del Agua/análisisRESUMEN
Los florecimientos algales nocivos (FAN) son eventos naturales que ocurren cuando una o más especies de microalgas proliferan en concentraciones que pueden causar daño a los organismos acuáticos y a seres humanos que los consuman. En las últimas décadas, se ha registrado a nivel mundial un aumento de eventos de mortalidad alarmante de organismos acuáticos e intoxicaciones en seres humanos causadas por toxinas producidas por microalgas. En Guatemala existe escasa información sobre eventos FAN, no obstante, en diciembre de 2018 ocurrió un FAN en la costa Pacífico de Guatemala. La Comisión Nacional para la Vigilancia y el Control de la Marea Roja Tóxica recolectó muestras biológicas e identificó la presencia de 3,000 cel/L del dinoflagelado Pyrodinium bahamense. El bioensayo en ratón de las muestras, indica concentraciones de saxitoxina de 8,236 UR/100 g y 6,559 UR/100 g, para los días 20 y 27 de diciembre, respectivamente. Estas concentraciones no han sido reportadas previamente en Guatemala, y pueden ser potencialmente tóxicas para la salud pública. Se recomienda mantener un monitoreo de FAN para prevenir impactos negativos en la salud pública y ambiental.
Harmful algal blooms (HABs) are natural events that occur when one or more species of microalgae proliferate at concentrations that can cause damage to aquatic organisms and to those who consume them. In Guatemala very little information exists on HAB events, although in December 2018 has occurred a HABs at the Pacific Coast of Guatemala. A biological sample were collected by the National Commission for Surveillance and Control of Toxic Red Tide. The samples showed 3,000 cel/L of the dinoflagellate Pyrodinium bahamense. During the bioassay for saxitoxin, the concentrations reached 8,236 MU/100 g and 6,559 MU/100 g, for December 20th and 27th, respectively. These concentrations has not been reported previously for Guatemala, and could be a risk in the public health. This result emphasizes the importance of maintaining the HABS monitoring program to prevent negative impact on public environmental health.