Role of Nutrients in Phytoplankton Development during a Winter Diatom Bloom in a Eutrophic South American Estuary (Bahía Blanca, Argentina)

Abstract

The Bahía Blanca Estuary is considered highly eutrophic. Long-term studies have shown that the winter-early spring bloom can be considered the development of a diatom assemblage with Thalassiosira curviseriata as the dominant species. Since 2003, several changes have been observed in the annual pattern of nutrients and phytoplankton. To assess the availability of nutrients and their relationship with phytoplankton development, nutrient variability was studied during a winter bloom in 2003 (April 22-September 4). Nitrite, nitrate, ammonium, phosphate, silicates, chlorophyll-a, phytoplankton abundance, particulate organic matter, and physicochemical parameters were measured in surface water at Cuatreros Port. In the Sauce Chico River mouth, we determined the concentration of nutrients to estimate the input of this river. The results of this study were compared with those of a previous usual diatom bloom from 2002. In 2003, the bloom was dominated by the Cyclotella sp. with high chlorophyll-a concentrations (26.5-40.4 lg L À1 ). Thalassiosira curviseriata was present only at three sampling dates, reaching up to 19% of the total abundance. Mean values of dissolved oxygen, nitrate, oxygen saturation percentage, and salinity were significantly higher in 2003 than in 2002, while N:P ratios were significantly lower. Si was never limiting. A shift in the limiting nutrient between the years (N in 2003 and P in 2002) could have lead to a change in species dominance during the blooms. Results suggest that the nutrients levels in the coastal ecosystems at Cuatreros Port play an important role in the control of phytoplankton dynamics during the productive period and partially explain its interannual variability.

Chitin determination on marine seston in a shallow temperate estuary (Argentina)

“…Additionally, SPM was negatively associated with phaeopigments, which were the product of chlorophyll a degradation and indicator of zooplankton grazing DUTTO et al, 2012;SPETTER et al, 2015), contributed to the fraction <20 µm of SPM in both stations. Dynamic processes such as cuticles molting and senescence of planktonic organisms, resulting in a continuous supply of chitin to the marine environment (ALLDREDGE; GOTSCHALK, 1990), might also contributed to chitin pool in the fraction <20 µm SPM in this system.…”

Seasonal and Tidal Dynamics of Water Temperature, Salinity, Chlorophyll-a, Suspended Particulate Matter, Particulate Organic Matter, and Zooplankton Abundance in a Shallow, Mixed Estuary (Bahía Blanca, Argentina)

“…Phytoplankton community in the BBE has been characterized by a marked, recurrent pattern, with a single winter-early spring diatom bloom (e.g., Guinder, Popovich, and Perillo, 2009a;Popovich et al, 2008;Spetter et al, 2013). The bloom has been attributed to a high nutrient concentration and the relaxation of zooplankton grazing pressure because of the low water temperatures (Popovich et al, 2008).…”

“…The temporal and spatial dynamics of physicochemical (temperature, salinity, photosynthetic pigments, dissolved nutrients) and biological variables (phytoplankton, zooplankton) have been studied extensively (e.g., Guinder, Popovich, and Perillo, 2009a;Perillo and Piccolo, 1991;Perillo et al, 2004;Piccolo and Perillo, 1990;Popovich et al, 2008;Spetter et al, 2013). However, few of these works have considered the short-term variability associated with tidal cycles.…”

A Remote Sensing Algorithm of Column-Integrated Algal Biomass Covering Algal Bloom Conditions in a Shallow Eutrophic Lake

“…Sensitivity analysis demonstrated that the estimated algal biomass integrated from the water surface to 40 cm has the greatest influence on the estimated column integrated algal biomass. This algorithm can be used to explore the long-term variation of algal biomass to improve long-term analysis and management of eutrophic lakes.Bahía Blanca Estuary in Argentina [23,24] and the Great Barrier Reef in Australia [25,26]. Inland eutrophication has led to increasing occurrences of cyanobacteria blooms, with impact on water, fisheries and biodiversity [27,28].Remote sensing has been used to assess eutrophication status with major success.…”

“…Bahía Blanca Estuary in Argentina [23,24] and the Great Barrier Reef in Australia [25,26]. Inland eutrophication has led to increasing occurrences of cyanobacteria blooms, with impact on water, fisheries and biodiversity [27,28].…”