Significance and fate of bacterial production in oligotrophic lakes in British Columbia

2000 ◽  
Vol 57 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Thomas Weisse ◽  
Erland MacIsaac
Keyword(s):  
British Columbia ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Trophic Levels ◽  
Lake Productivity ◽  
Relative Contribution ◽  
Carbon Biomass ◽  
Productivity Data ◽  
High Nutrient ◽  
Heterotrophic Nanoflagellate

We measured bacterial abundance, biomass, production rates, and grazing losses to protozoans in three oligotrophic British Columbia lakes and analyzed bacteria abundance and lake productivity data from 11 other lakes, most fertilized with inorganic nutrients to increase their productivity for juvenile salmon. Bacteria contributed about 24% to the phytoplankton-bacteria carbon biomass in the most ultraoligotrophic lakes, and their relative contribution declined to <11% with increasing lake productivity. At increasingly high nutrient loadings to the lakes, bacteria abundance increased and was closely correlated with phytoplankton biomass and productivity. Heterotrophic nanoflagellate (HNF) abundance was positively correlated with bacterial numbers. Grazing experiments revealed that HNF were the primary pathway for moving bacterial production to higher trophic levels in oligotrophic British Columbia lakes, and predation by the ciliate and rotifer microzooplankton community appeared to exert top-down control over the abundance of HNF and the transfer of carbon from bacteria. The HNF and microzooplankton, in turn, were affected by the abundance of crustacean mesozooplankton, principally copepods in our experiments.

scholarly journals Fe and C co-limitation of heterotrophic bacteria in the naturally fertilized region off the Kerguelen Islands

2015 ◽  
Vol 12 (6) ◽  
pp. 1983-1992 ◽  
Author(s):  
I. Obernosterer ◽  
M. Fourquez ◽  
S. Blain
Keyword(s):  
Trace Metal ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Heterotrophic Bacteria ◽  
Kerguelen Islands ◽  
High Nutrient ◽  
Limiting Nutrient ◽  
Heterotrophic Metabolism ◽  
Heterotrophic Production

Abstract. It has been univocally shown that iron (Fe) is the primary limiting nutrient for phytoplankton metabolism in high-nutrient, low-chlorophyll (HNLC) waters, yet the question of how this trace metal affects heterotrophic microbial activity is far less understood. We investigated the role of Fe for bacterial heterotrophic production and growth at three contrasting sites in the naturally Fe-fertilized region east of the Kerguelen Islands and at one site in HNLC waters during the KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2) cruise in spring 2011. We performed dark incubations of natural microbial communities amended either with iron (Fe, as FeCl3) or carbon (C, as trace-metal clean glucose), or a combination of both, and followed bacterial abundance and heterotrophic production for up to 7 days. Our results show that single and combined additions of Fe and C stimulated bulk and cell-specific bacterial production at the Fe-fertilized sites, while in HNLC waters only combined additions resulted in significant increases in these parameters. Bacterial abundance was enhanced in two out of the three experiments performed in Fe-fertilized waters but did not respond to Fe or C additions in HNLC waters. Our results provide evidence that both Fe and C are present at limiting concentrations for bacterial heterotrophic activity in the naturally fertilized region off the Kerguelen Islands in spring, while bacteria were co-limited by these elements in HNLC waters. These results shed new light on the role of Fe in bacterial heterotrophic metabolism in regions of the Southern Ocean that receive variable Fe inputs.

The contribution of heterotrophic nanoflagellate grazing towards bacterial mortality in tropical waters: comparing estuaries and coastal ecosystems

2011 ◽  
Vol 62 (4) ◽  
pp. 414 ◽  
Author(s):  
Chui Wei Bong ◽  
Choon Weng Lee
Keyword(s):  
Coastal Waters ◽  
Bacterial Production ◽  
Trophic Status ◽  
Bacterial Abundance ◽  
Temperature Optimum ◽  
Viral Lysis ◽  
Tropical Waters ◽  
Order Of Magnitude ◽  
Heterotrophic Nanoflagellate ◽  
Straits Of Malacca

Heterotrophic nanoflagellate (HNF) grazing depends on both temperature and trophic status of an ecosystem. As most microbes already function at their temperature optimum in tropical waters, we hypothesised that HNF grazing rates would be higher in more productive sites such as estuaries than in less productive areas such as coastal waters. We sampled two estuaries and three coastal sites along the Straits of Malacca and the South China Sea near the Malaysia Peninsula. Bacterial abundance ranged 0.9–6.3 × 106 cells mL–1, whereas HNF abundance ranged 1.8–10.1 ×103 cells mL–1. Bacterial production ranged 1.1–12.7 × 105 cells mL–1 h–1, whereas HNF grazing rates were an order of magnitude lower at 1.0–78.5 × 104 cells mL–1 h–1. Bacterial abundance, net bacterial production and HNF grazing rates were higher in estuaries than coastal waters but HNF abundance did not differ between the two areas. Across all stations, HNF grazing rates increased with bacterial production, and accounted for ~33% of bacterial production. Our results suggest that in the tropical waters studied, there was a bacterial production–grazing imbalance. Other loss factors such as viral lysis, sedimentation or the presence of benthic filter feeders could account for this imbalance.

scholarly journals Differing Growth Responses of Major Phylogenetic Groups of Marine Bacteria to Natural Phytoplankton Blooms in the Western North Pacific Ocean

2011 ◽  
Vol 77 (12) ◽  
pp. 4055-4065 ◽  
Author(s):  
Yuya Tada ◽  
Akito Taniguchi ◽  
Ippei Nagao ◽  
Takeshi Miki ◽  
Mitsuo Uematsu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
North Pacific ◽  
Bacterial Production ◽  
Western North Pacific ◽  
Bacterial Abundance ◽  
North Pacific Ocean ◽  
Growth Potential ◽  
Phytoplankton Blooms ◽  
Content Type

ABSTRACTGrowth and productivity of phytoplankton substantially change organic matter characteristics, which affect bacterial abundance, productivity, and community structure in aquatic ecosystems. We analyzed bacterial community structures and measured activities inside and outside phytoplankton blooms in the western North Pacific Ocean by using bromodeoxyuridine immunocytochemistry and fluorescencein situhybridization (BIC-FISH).Roseobacter/Rhodobacter, SAR11,Betaproteobacteria,Alteromonas, SAR86, andBacteroidetesresponded differently to changes in organic matter supply.Roseobacter/Rhodobacterbacteria remained widespread, active, and proliferating despite large fluctuations in organic matter and chlorophylla(Chl-a) concentrations. The relative contribution ofBacteroidetesto total bacterial production was consistently high. Furthermore, we documented the unexpectedly large contribution ofAlteromonasto total bacterial production in the bloom. Bacterial abundance, productivity, and growth potential (the proportion of growing cells in a population) were significantly correlated with Chl-aand particulate organic carbon concentrations. Canonical correspondence analysis showed that organic matter supply was critical for determining bacterial community structures. The growth potential of each bacterial group as a function of Chl-aconcentration showed a bell-shaped distribution, indicating an optimal organic matter concentration to promote growth. The growth ofAlteromonasandBetaproteobacteriawas especially strongly correlated with organic matter supply. These data elucidate the distinctive ecological role of major bacterial taxa in organic matter cycling during open ocean phytoplankton blooms.

Productivity of Owikeno Lake, British Columbia

1969 ◽  
Vol 26 (5) ◽  
pp. 1363-1368 ◽  
Author(s):  
David W. Narver
Keyword(s):  
British Columbia ◽  
North America ◽  
Primary Productivity ◽  
Sockeye Salmon ◽  
Nursery Area ◽  
The Other ◽  
Lake Productivity ◽  
The Third ◽  
Annual Total

Although Owikeno Lake is the third highest producer of adult sockeye salmon in North America in terms of mean annual total return (catch plus escapement) per unit of lake nursery area, limited measurements of other indices of lake productivity suggest that its primary productivity is much lower than that of the other four highest sockeye-producing lakes. The implications of these results to sockeye production are discussed.

Transfer of bacterial production based on labile carbon to higher trophic levels in an oligotrophic pelagic system

2012 ◽  
Vol 69 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Carolyn Faithfull ◽  
Magnus Huss ◽  
Tobias Vrede ◽  
Jan Karlsson ◽  
Ann-Kristin Bergström
Keyword(s):  
Bacterial Production ◽  
Perca Fluviatilis ◽  
Trophic Levels ◽  
Fish Growth ◽  
Crustacean Zooplankton ◽  
Calanoid Copepods ◽  
Glucose Addition ◽  
Perch Perca Fluviatilis ◽  
Labile C ◽  
Positive Effect

Additions of labile organic carbon (C) enhanced bacterial production (BP) and were associated with increases in crustacean zooplankton and planktivorous fish biomasses. This was shown in a mesocosm experiment where we traced the contribution of BP to zooplankton and fish using stable isotopes and labile glucose-C as a biomarker. BP increased with glucose-C addition, and all zooplankton and fish incorporated some glucose-C. However, the effect of labile-C addition on zooplankton was taxa-dependant, as although cladocerans incorporated the most labile-C, increased BP did not affect cladoceran biomass. Instead, calanoid copepod biomass increased with glucose addition. This suggests that the ability to selectively graze on high quality food, such as bacterial grazing protists capable of trophic upgrading, had a stronger positive effect on calanoid copepods biomass than unselective grazing on bacteria and protists had on cladoceran biomass. Higher BP was associated with increased survival and population growth of young-of-the-year perch ( Perca fluviatilis ) when stocked at high densities, which suggested that BP had a density-dependant positive effect on fish growth.

scholarly journals Seasonal and spatial variation of bacterial production and abundance in the northern Levantine Sea

2017 ◽  
Vol 18 (1) ◽  
pp. 97 ◽  
Author(s):  
N. YUCEL
Keyword(s):  
Bacterial Production ◽  
Bacterial Abundance ◽  
Phytoplankton Bloom ◽  
Euphotic Zone ◽  
Organic Carbon Content ◽  
Spring Phytoplankton Bloom ◽  
Levantine Sea ◽  
Spatial And Temporal Heterogeneity ◽  
The Mean ◽  
Mean Time

Spatial and temporal heterogeneity in bacterial production and abundance in relation to ambient bio-physicochemical parameters has been investigated in the Levantine Sea. Five stations with different trophic states in an area extending from highly eutrophic Mersin bay to the mesotrophic Rhodes gyre area including the oligotrophic offshore waters were sampled four times. Integrated bacterial production varied between 6.1 and 90.3 µg C m-2 d-1 with higher rates occurring during September 2012 in offshore waters. Bacterial abundance ranged between 0.18 and 7.3 x 105 cells ml-1 within the euphotic zone and was generally higher up to 100 meters throughout the study period. In offshore waters, bacterial production (0.401 to 0.050 µg C m-3 d-1), abundance (4.5 to 1.6 x 105 cells ml-1) and depth of the productive layer decreased from 150 to 75 meters westward along the transect. Although the highest abundance was observed in July 2012 in offshore waters, the highest activity was measured in September 2012. These results indicated that the temperature played a key role in regulating bacterial abundance and production in the area. High chlorophyll concentrations in March did not correspond to high bacterial abundance and production at the same time. Increase in dissolved organic carbon content following spring phytoplankton bloom and the increase in temperature in the mean time might have enhanced the bacterial activity towards summer.

Influence of organic carbon cycling on the fate of persistent organic pollutants in marine environments

2020 ◽  
Author(s):  
Anna Sobek ◽  
Inna Nybom ◽  
Hans Peter Arp ◽  
Naiara Berrojalbiz ◽  
Nathan Charlton ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Baltic Sea ◽  
Water Column ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Data Set ◽  
Preliminary Results ◽  
Relative Contribution ◽  
High Nutrient ◽  
Total Sediment

&lt;p&gt;Persistent organic pollutants (POPs) are ubiquitously present in the aquatic environment. They are hydrophobic substances that sorb to organic carbon (OC), and thus their environmental fate is closely linked to OC fluxes and pools. In this project, we test the hypothesis that future changes in the OC cycle can influence POP flux from air to sediment and reduce the POP sink in Baltic Sea sediments. The hypothesis relies on the assumption that the OC sorption capacity is affected by the relative contribution of terrestrial OC as well as the trophic status (oligotrophic versus eutrophic) of the area. Four different coastal sites were sampled, to capture different carbon regimes in terms of nutrient status and level of terrestrial OC influence. Concentrations of POPs were analysed along high-resolution sediment porewater- bottom water interface profiles, in total sediment, suspended matter collected in sediment traps and plankton, in the water column and in air. Stable carbon isotope signatures (&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C) showed that the sites are different in terms of the influence of terrestrial organic matter, and the sites differ in nutrient conditions.&lt;/p&gt;&lt;p&gt;Preliminary results demonstrate that in general, sediments (three sites analysed) act as a source of PAHs to overlying water, whereas sediment and water more often are in equilibrium for PCBs, although there are variations for individual compounds. At the high nutrient-low terrestrial site, which was sampled at two different seasons, both air and water concentrations were higher for PAHs and PCBs in the autumn compared to the summer, indicating the importance of air as source of these contaminants to the water column. Accordingly, air seems an important source of PAHs to the water column in the low terrestrial-low nutrient site, as concentrations in the water column are increasing towards the water surface, whereas this was not observed for PCBs at the same site. Preliminary results from two contrasting sites in the Gulf of Finland, both with high nutrient levels but with different relative contribution of terrestrial OC, demonstrate higher total sediment concentrations of PAHs in the sediment with more marine OC, which was not observed as clearly for PCBs. Data from the water column indicate that marine OC is more efficient in sorbing POPs as air and water concentrations were similar at both sites, even though the OC vertical export at the high terrestrial site was more than double compared to the low terrestrial site. The full data set, will allow for further evaluation of hypotheses on the links between OC cycling and contaminant fate in the Baltic Sea.&lt;/p&gt;

Investigating the in-situ bacterial production of aquatic fluorescent organic matter using a freshwater laboratory model

2020 ◽  
Author(s):  
Eva Perrin ◽  
John Attridge ◽  
Robin Thorn ◽  
Stephanie Sargeant ◽  
Darren Reynolds
Keyword(s):  
Organic Matter ◽  
Nutrient Availability ◽  
Bacterial Production ◽  
Nutrient Loading ◽  
Laboratory Model ◽  
Freshwater Systems ◽  
Laboratory Conditions ◽  
Fluorescence Characteristics ◽  
High Nutrient

&lt;p&gt;This research explores the &lt;em&gt;in-situ&lt;/em&gt; bacterial production of aquatic fluorescent organic matter (AFOM) under controlled laboratory conditions. Whilst fluorescence techniques have long been used to monitor AFOM distribution, origin and dynamics within aquatic systems, the extent to which AFOM characteristics are defined by microbial processing in surface freshwaters has largely been overlooked. Current convention champions the assumption that humic-like (Peak C) and protein-like (Peak T) fluorescence signatures are exclusively derived from terrestrial (allochthonous) or microbial (autochthonous) origins respectively, with Peak T having been directly correlated with microbial enumeration. Under intensifying anthropogenic perturbations and changing catchment characteristics, the complexities associated with bacterial-organic matter (OM) interactions in freshwater systems are increasing, challenging our understanding as to the origin and fate of aquatic OM. To what extent the observed AFOM in freshwater systems is defined by bacterial processing and how such processing may be influenced by nutrient availability are key knowledge gaps that need to be addressed. Previous research has observed the &lt;em&gt;in-situ&lt;/em&gt; bacterial production of humic-like compounds in a laboratory model system with a high-nutrient and high-carbon content synthetic growth medium. This work describes a non-fluorescing, simulated freshwater matrix which is low in both nutrient and organic carbon concentrations. Using this model, growth curve incubation experiments have been undertaken over a 48-hour period with a monoculture laboratory strain of &lt;em&gt;Pseudomonas aeruginosa&lt;/em&gt;. Microbiological and fluorescence analyses undertaken at regular time intervals demonstrate the bacterial production of humic-like OM (Peak C) under oligotrophic (after 8hrs) and simulated high-nutrient conditions (after 6hrs). These findings, albeit under laboratory conditions, are important as they show that this fluorescence region, currently viewed as allochthonous in origin, can also represent labile OM generated &lt;em&gt;in-situ&lt;/em&gt; by bacteria and, furthermore, that this bacterial production increases as a function of nutrient loading. In addition, the data quantitatively demonstrates that fluorescence intensities increase independently of cell density. These results challenge the assumption that humic-like AFOM is exclusively terrestrial in origin and suggest that bacteria may &amp;#8220;engineer&amp;#8221; OM&lt;em&gt; in-situ&lt;/em&gt; that gives rise to these fluorescence characteristics as a function of metabolism. Importantly, nutrient availability is a key driver of metabolic activity, outlining the potential for the use of fluorescence as a marker for stream metabolism as opposed to a measure of bacterial numbers. Further development of the laboratory model via the utilisation of environmentally-sourced bacterial communities is required. Ultimately, this laboratory model will inform field studies that look to improve our understanding of how microbial communities respond to catchment stressors, and how these responses influence AFOM fluorescence signatures and ultimately the origin and fate of OM in freshwater systems.&lt;/p&gt;

scholarly journals Carbon dynamics in highly heterotrophic subarctic thaw ponds

2015 ◽  
Vol 12 (23) ◽  
pp. 7223-7237 ◽  
Author(s):  
T. Roiha ◽  
I. Laurion ◽  
M. Rautio
Keyword(s):  
Bacterial Production ◽  
Environmental Gradients ◽  
Light Limitation ◽  
Late Winter ◽  
Strongly Correlated ◽  
Terrestrial Carbon ◽  
High Concentration ◽  
Strong Light ◽  
Carbon Biomass ◽  
Arctic Regions

Abstract. Global warming has accelerated the formation of permafrost thaw ponds in several subarctic and arctic regions. These ponds are net heterotrophic as evidenced by their greenhouse gas (GHG) supersaturation levels (CO2 and CH4), and generally receive large terrestrial carbon inputs from the thawing and eroding permafrost. We measured seasonal and vertical variations in the concentration and type of dissolved organic matter (DOM) in five subarctic thaw (thermokarst) ponds in northern Quebec, and explored how environmental gradients influenced heterotrophic and phototrophic biomass and productivity. Late winter DOM had low aromaticity indicating reduced inputs of terrestrial carbon, while the high concentration of dissolved organic carbon (DOC) suggests that some production of non-chromophoric dissolved compounds by the microbial food web took place under the ice cover. Summer DOM had a strong terrestrial signature, but was also characterized with significant inputs of algal-derived carbon, especially at the pond surface. During late winter, bacterial production was low (maximum of 0.8 mg C m−3 d−1) and was largely based on free-living bacterioplankton (58 %). Bacterial production in summer was high (up to 58 mg C m−3 d−1), dominated by particle-attached bacteria (67 %), and strongly correlated with the amount of terrestrial carbon. Primary production was restricted to summer surface waters due to strong light limitation deeper in the water column or in winter. The phototrophic biomass was equal to the heterotrophic biomass, but as the algae were mostly composed of mixotrophic species, most probably they used bacteria rather than solar energy in such shaded ponds. Our results point to a strong heterotrophic energy pathway in these thaw pond ecosystems, where bacterioplankton dominates the production of new carbon biomass in both summer and winter.

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