SciELO - Scientific Electronic Library Online

 
vol.39 número5Comparative assessment of widespread irrigation with low quality mine-water in undisturbed and rehabilitated mine-lands in the upper Olifants using the ACRU2000 modelMulti-criteria decision making for water resource management: a case study of the Gediz River basin, Turkey índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Articulo

Indicadores

Links relacionados

  • En proceso de indezaciónCitado por Google
  • En proceso de indezaciónSimilares en Google

Compartir


Water SA

versión On-line ISSN 1816-7950
versión impresa ISSN 0378-4738

Resumen

KASELOWSKI, T  y  ADAMS, JB. Not so pristine - characterising the physico-chemical conditions of an undescribed temporarily open/closed estuary. Water SA [online]. 2013, vol.39, n.5, pp.627-636. ISSN 1816-7950.

A rapid ecological water requirement study of the Department of Water Affairs in 2009 classified the Goukamma Estuary as largely natural with few modifications, i.e., in an A/B state. However this detailed 13-month study showed that the estuary is impacted. Salinity stratification and hypoxic conditions (dissolved oxygen (DO) < 3 mgℓ-1) were measured during both open and closed mouth states. The Goukamma Estuary is a blackwater system and in its natural state is expected to be nutrient poor. However high nutrient concentrations were measured in the middle and upper reaches of the estuary, adjacent to cattle farms. Nutrient concentrations represented mesotrophic (DIN > 500 µg·ℓ-1) to eutrophic conditions (DIP > 25 µg·ℓ-1). Nutrient input stimulated microalgae to attain a high biomass, ranging between 0.3 and 112 µg·ℓ-1 (average 7.7 ± 1.3 µg·ℓ-1) and 0.8 and 289 µg·ℓ-1 (average 21.1 ± 4.4 µg·ℓ-1) during the open and closed mouth states, respectively. Exacerbated by natural salinity stratification which effectively limits oxygenation of the water column, unnaturally high nutrient concentrations, microalgal blooms and coinciding organic loads all indicate poor water quality of the Goukamma Estuary. This research showed that detailed studies involving field measurements of water quality are required before the present health status of an estuary can be assessed.

Palabras clave : Temporarily open/closed estuaries; blackwater system; water quality; stratification; hypoxia; DIN; DIP; microalgae biomass.

        · texto en Inglés     · Inglés ( pdf )

 

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons