Picophytoplankton community in a tropical estuary: Detection of Prochlorococcus-like populations

Mitbavkar, Smita; Rajaneesh, K.M.; Anil, Arga Chandrashekar; Sundar, D.

doi:10.1016/j.ecss.2012.05.002

Cited by 35 publications

(13 citation statements)

References 24 publications

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“…A similar pattern of dominance has been observed in other estuaries, e.g. the York River Estuary, a subestuary of the lower Chesapeake Bay (Ray et al 1989), Pensacola Bay (Murrell and Lores 2004) and the Zuari estuary (Mitbavkar et al 2012). In the lower York River, PC-rich cells were up to eight-fold more abundant than were PErich cells (Ray et al 1989).…”

Section: Discussionsupporting

confidence: 80%

Picophytoplankton abundance and distribution in three contrasting periods in the Pearl River Estuary, South China

Zhang

et al. 2013

Mar. Freshwater Res.

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Abundance and distribution characteristics of three picophytoplankton groups (Synechococcus, Prochlorococcus and picoeukaryotes), identified by flow cytometer, and two types of picocyanobacteria (phycoerythrin and phycocyanin-rich strains), determined by epifluorescence microscope, were assessed in three contrasting periods in the Pearl River Estuary, South China. The average abundance of picophytoplankon and picocyanobacteria was 104 cells mL–1 in the two summer observations and 103 cells mL–1 in winter. Low cell density in the cold season was probably due to high turbidity and low water temperature. Prochlorococcus was detected within the estuarine plume in the summer investigations and was undetectable in the winter. Higher abundance and the further upstream occurrence of Prochlorococcus in the summer of 2011 were mainly associated with extreme low river flows. We presumed that Prochlorococcus abundance and distribution range were balanced by river discharge and saline-water intrusion. Synechococcus was the dominant group in the inner estuary. Similar to Prochlorococcus, Synechococcus distribution was related with freshwater inflow. The river inflow exerted strong limitation on Synechococcus and Prochlorococcus, with this effect weakening along the salinity gradient. Picoeukaryotes were the least abundant category among picophytoplankton and showed a different distribution pattern from that of Synechococcus and Prochlorococcus. For picocyanobacteria, there was a clear spatial gradient with phycocyanin-rich strains dominant in the upper estuary, and phycocyanin-rich and phycoerythrin-rich cells dominant downstream. A significant negative correlation was observed between phycocyanin-rich cells to phycoerythrin-rich cells ratio and salinity.

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Section: Discussionsupporting

confidence: 80%

Picophytoplankton abundance and distribution in three contrasting periods in the Pearl River Estuary, South China

Zhang

et al. 2013

Mar. Freshwater Res.

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“…These studies revealed that PE rich SYN dominates higher saline waters whereas PC rich SYN are abundant in lower saline waters (Murrell and Lores, 2004). Sub-groups of PE rich SYN were also detected in the Mississippi river plume (Liu et al, 2004), Pearl River estuary (Lin et al, 2010) and the Zuari estuary (Mitbavkar et al, 2012) implying the importance of salinity on the distribution of the SYN groups. PP plays an important role in the microbial loop by forming the base of food chain and serving as food for many protists and small invertebrates species (Azam, 1983;Pomeroy, 1974).…”

Section: Introductionmentioning

confidence: 86%

“…Studies on PP are well established in the Pacific and Atlantic Oceans whereas comparatively in the Indian Ocean only a few observations have been made (Brown et al, 1999;Campbell et al, 1998). Apart from the open ocean, the importance of PP in coastal regions is now being highlighted (Mitbavkar et al, 2012;Murrell and Lores, 2004).…”

Section: Introductionmentioning

confidence: 99%

Factors controlling the temporal and spatial variations in Synechococcus abundance in a monsoonal estuary

Rajaneesh

Mitbavkar

2013

Marine Environmental Research

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Temporal and spatial variations in Synechococcus abundance were investigated over an annual cycle (February'10-January'11) along a salinity gradient (0-35) in the tropical Zuari estuary, influenced by south-west monsoons. Synechococcus exhibited salinity preferences with phycoerythrin-rich cells at salinities >2 (Synechococcus-PEI), >20 (Synechococcus-PEII) and <1 (Synechococcus-PEIII) whereas phycocyanin-rich (Synechococcus-PC) dominant at lower salinities. Downstream stratification during monsoon caused Synechococcus group segregation in the surface and near-bottom waters. During monsoon-break and non-monsoon period stabilized waters, increased salinity, temperature, solar radiation and low rainfall favored high Synechococcus abundance whereas unstable waters, increased turbidity and low solar radiation during active monsoon lowered abundance. SYN-PC positively co-related with nitrate and phosphate and SYN-PEI with phosphate. Synechococcus contribution to phytoplankton carbon biomass ranged from 9 to 29%. In monsoonal estuaries, rainfall intensity regulates freshwater runoff which modulates the estuarine environment, creating temporal-spatial niche segregation of Synechococcus groups thereby serving as indicator organisms of the estuarine hydrodynamics.

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“…The main shift in sub-community succession detected in this study was the co-occurrence of Phyto-PC and Phyto-PE in summer 2012, in contrast with the longer-lasting bloom of Phyto-PC and absence of Phyto-PE in 2013. These results suggested that Phyto-PC is likely a euryhaline cyanobacteria, while Phyto-PE is likely a marine, high-salinity Synecochoccus-like cyanobacteria (Mitbavkar et al 2012). Since marine Synechococcus have an obligate salt requirement (Waterbury et al 1986), the decreases in salinity below 75% of full salinity that occurred in summer 2013 are likely the primary cause of the low competitive advantage of Phyto-PE in 2013.…”

Section: Phytoplanktonmentioning

confidence: 97%

Seasonal dynamics of dissolved, particulate and microbial components of a tidal saltmarsh-dominated estuary under contrasting levels of freshwater discharge

Bittar

Berger

Birsa

et al. 2016

Estuarine, Coastal and Shelf Science

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Tidal Spartina-dominated saltmarshes and estuaries on the Southeast US coast are global hotspots of productivity. In coastal Georgia, tidal amplitudes and saltmarsh productivity are the highest along the Southeast US coast. Coastal Georgia is characterized by a humid subtropical seasonal climate, and inter-annual variability in precipitation, and freshwater discharge. The 2012-2013 timeframe encompassed contrasting levels of discharge for the Savannah River, a major Georgia river, with a 4.3-fold greater discharge in summer 2013 relative to summer 2012. In situ measurements of temperature, salinity, precipitation and Secchi depth, and water samples were collected weekly at high tide throughout 2012 and 2013 from the Skidaway River Estuary, a tidal saltmarsh-dominated estuary in coastal Georgia influenced by Savannah River hydrology. The effects of elevated discharge on the seasonal trends of water column components were evaluated. The shift from low discharge (2012) to high discharge (2013) led to decreased salinity in summer 2013, but no significant increases in inorganic nutrient (NH4, NOx, SiO2 and PO4) concentrations. Dissolved inorganic carbon (DIC) concentrations decreased, and DIC stable isotopic signatures (δ 13 C-DIC values) were depleted in summer 2013 relative to summer 2012. In 2013 dissolved organic carbon (DOC) concentrations, chromophoric and fluorescent dissolved organic matter (DOM: CDOM, FDOM) intensities, specific UV-absorbance (SUVA254) and relative humic-like fluorescence were all higher than in 2012, indicating that, as discharge increased in 2013, estuarine water became enriched in terrigenous DOM. Secchi depth and particulate organic carbon (POC) and nitrogen (PON) concentrations displayed clear seasonal patterns that were not significantly altered by discharge. However,  13 C-POC and  15 N-PON isotopic signatures indicated higher terrigenous contributions at elevated discharge. Discharge influenced cyanobacterial composition, but did not affect total abundance of phytoplankton (<52

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Picophytoplankton community in a tropical estuary: Detection of Prochlorococcus-like populations

Cited by 35 publications

References 24 publications

Picophytoplankton abundance and distribution in three contrasting periods in the Pearl River Estuary, South China

Picophytoplankton abundance and distribution in three contrasting periods in the Pearl River Estuary, South China

Factors controlling the temporal and spatial variations in Synechococcus abundance in a monsoonal estuary

Seasonal dynamics of dissolved, particulate and microbial components of a tidal saltmarsh-dominated estuary under contrasting levels of freshwater discharge

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