Potential effects of climate changes on the marine ecosystem stability: assessment of the water quality

MARCOVECCHIO, JORGE E.; BUZZI, NATALIA; TÁRTARA, MATÍAS; SPETTER, CARLA; SIMONETTI, PIA

Marine Ecology in a Changing World

CRC Press

Lugar: Boca Raton, Florida; Año: 2013; p. 16 - 75

Climate extreme conditions strongly affect life development and distribution on the planet. Considering not only the intensity and duration of the climatic anomaly but also the characteristics of the considered ecosystem (i.e. coastal, oceanic), the corresponding impacts can range from imperceptible to catastrophic ones. Changes in the environmental conditions lead to potential variations in their both physico-chemical and oceanographic scenarios, determining modifications in the distribution and behavior of different populations, and eventually in fisheries and exploitation of resources. A possible manifestation of these changes in conditions within marine ecosystems, as a function of climate anomalies, is the loss of stability of the water column, which leads to changes in their physical, chemical and/or oceanographic variables, affecting water quality. In this regard it is highlighted that both the coastal and oceanic systems are dominated by hydrological and physical processes governing the transport of materials and energy regimes. (Esta oración la encuentro confusa Jorge, no llego a entenderla, no sabría que cambio realizar tal vez en realidad es un problema en comprensión mía del texto, no entiendo muy bien a que apunta)(A mi modo de ver, creo que la frase está bien).The major climatic changes that may affect marine ecosystems (i.e. Sea level rise; changes in seawater temperature; changes in precipitation regimes; changes in the path, frequency and intensity of storms; etc.) determine different phenomena on coastal and/or oceanic systems. In coastal areas, a wide range of effects can be produced at different scales, from (i.e. increased turbidity due to continental runoff overdischarge; overload of nutrients linked to increased rainfall; drastic changes in salinity during periods of drought or flood; etc.) and up to the or even ones (i.e. changes in ocean surface circulation patterns due to freshwater over-discharge; changes in CO2 levels that determine significant variations in pH/alkalinity; etc.). These kinds of phenomena could strongly influence aquatic communities on the global scale, affecting plankton dynamics and leading to regime shifts in the pelagic realm. In addition, these type of changes could drive severe problems on the coastal ecosystems as eutrophication, erosion or saline intrusion / salinization of aquifers; while on the oceanic ones the main problems which have been identified are oceanic acidification; potential collapse of the great processes of the planet´s climatic regulation (i.e. Thermohaline circulation -THC- ; South Asia monsoon -SAM- ; Circum Antarctic low pressure belt -CALPB- ; among others); or, increase/decrease of upwelling-downwelling processes, which regulate the fertilization of the oceans.