The relative importance of heterotrophic bacteria to pelagic ecosystem dynamics varies with reservoir trophic state

ABSTRACT Understanding the effects of eutrophication on heterotrophic bacteria, a primary responder to eutrophication, is critical for predicting the responses of ecosystems to marine environmental pollution. Vibrio are indigenous in coastal water and of significance to geochemical cycling and public health. In this study, we investigated the diversity and assembly features of Vibrio, as well as their relationship with the environmental factors in the subtropical Beibu Gulf. We found that the alpha diversity of Vibrio increased in parallel with the trophic state they occupy. A Mantel test indicated that the trophic state was correlated to Vibrio beta diversity and the correlation gradually strengthened at higher trophic states. Variation partitioning analysis suggested that the geographic distance was an important factor impacting the variables of Vibrio communities in all the samples, but nutrients exerted more influence in the more highly eutrophic samples. Our results demonstrated that stochastic processes govern the turnover of marine Vibrio communities in the Beibu Gulf and that ecological drift was the most important process for assembly of the Vibrio communities.

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Relating marine ecosystem indicators to fishing and environmental drivers: an elucidation of contrasting responses

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp258 ◽

2009 ◽

Vol 67 (4) ◽

pp. 787-795 ◽

Cited By ~ 82

Author(s):

Jason S. Link ◽

Dawit Yemane ◽

Lynne J. Shannon ◽

Marta Coll ◽

Yunne-Jai Shin ◽

...

Keyword(s):

Marine Ecosystem ◽

Ecosystem Dynamics ◽

Environmental Drivers ◽

Ecosystem Change ◽

Relative Importance ◽

Ecosystem Sensitivity ◽

Ecosystem Indicators ◽

Proxy Indicators ◽

Key Drivers ◽

Ecosystem Drivers

Abstract Link, J. S., Yemane, D., Shannon, L. J., Coll, M., Shin, Y-J., Hill, L., and Borges, M. F. 2010. Relating marine ecosystem indicators to fishing and environmental drivers: an elucidation of contrasting responses. – ICES Journal of Marine Science, 67: 787–795. The usefulness of indicators in detecting ecosystem change depends on three main criteria: the availability of data to estimate the indicator (measurability), the ability to detect change in an ecosystem (sensitivity), and the ability to link the said change in an indicator as a response to a known intervention or pressure (specificity). Here, we specifically examine the third aspect of indicator change, with an emphasis on multiple methods to explore the “relativity” of major ecosystem drivers. We use a suite of multivariate methods to explore the relationships between a pre-established set of fisheries-orientated ecosystem status indicators and the key drivers for those ecosystems (particularly emphasizing proxy indicators for fishing and the environment). The results show the relative importance among fishing and environmental factors, which differed notably across the major types of ecosystems. Yet, they also demonstrated common patterns in which most ecosystems, and indicators of ecosystem dynamics are largely driven by fisheries (landings) or human (human development index) factors, and secondarily by environmental drivers (e.g. AMO, PDO, SST). How one might utilize this empirical evidence in future efforts for ecosystem approaches to fisheries is discussed, highlighting the need to manage fisheries in the context of environmental and other human (e.g. economic) drivers.

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The taxonomy of Bay of Quinte phytoplankton and the relative importance of common and rare taxa

Canadian Journal of Botany ◽

10.1139/b79-198 ◽

1979 ◽

Vol 57 (15) ◽

pp. 1591-1608 ◽

Cited By ~ 19

Author(s):

K. H. Nicholls ◽

E. C. Carney

Keyword(s):

Relative Abundance ◽

Trophic State ◽

Species Number ◽

Relative Importance ◽

Rare Taxa ◽

Sampling Locations ◽

The World

A listing of some 330 algal taxa found in the plankton of the Bay of Quinte during 1975 has been compiled and an indication given of the relative abundance at each of the eight sampling locations. Some difficulties related to interpretation of data on species number or 'richness' are discussed. It is suggested that particular attention in future years be given to several little-known taxa whose distribution and abundance will likely change should the trophic state of the Bay of Quinte be altered. Several species found in the Quinte collections have been only rarely reported from other parts of the world. Taxonomic notes on some problematical or otherwise interesting forms are included.

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Coupling of the spatial dynamic of picoplankton and nanoflagellate grazing pressure and carbon flow of the microbial food web in the subtropical pelagic continental shelf ecosystem

Biogeosciences Discussions ◽

10.5194/bgd-10-233-2013 ◽

2013 ◽

Vol 10 (1) ◽

pp. 233-263 ◽

Cited By ~ 4

Author(s):

K.-P. Chiang ◽

A.-Y. Tsai ◽

P.-J. Tsai ◽

G.-C. Gong ◽

S.-F. Tsai

Keyword(s):

Growth Rate ◽

Food Web ◽

Heterotrophic Bacteria ◽

Microbial Food Web ◽

Size Fractionation ◽

Pelagic Ecosystem ◽

Active Growth ◽

Bottom Up ◽

Bacteria Growth ◽

Oligotrophic Ecosystem

Abstract. In order to investigate the mechanism of spatial dynamics of picoplankton community (bacteria and Synechococcus spp.) and estimate the carbon flux of the microbial food web in the oligotrophic Taiwan Warm Current Water of subtropical marine pelagic ecosystem, we conducted size-fractionation experiments in five cruises by the R/V Ocean Research II during the summers of 2010 and 2011 in the southern East China Sea. We carried out culture experiments using surface water which, according to a temperature-salinity (T-S) diagram, is characterized as oligotrophic Taiwan Current Warm Water. We found a negative correlation bettween bacteria growth rate and temperature, indicating that the active growth of heterotrophic bacteria might be induced by nutrients lifted from deep layer by cold upwelling water. This finding suggests that the area we studied was a bottom-up control pelagic ecosystem. We suggest that the microbial food web of an oligotrophic ecosystem may be changed from top-down control to resource supply (bottom-up control) when a physical force brings nutrient into the oligotrophic ecosystem. Upwelling brings nutrient-rich water to euphotic zone and promotes bacteria growth, increasing the picoplankton biomass which increased the consumption rate of nanoflagellate. The net growth rate (growth rate–grazing rate) becomes negative when the densities of bacteria and Synechococcus spp. are lower than the threshold values. The interaction between growth and grazing will limit the abundances of bacteria (105-106 cells mL-1 and Synechococcus spp. (104-105 cells mL-1) within a narrow range, forming a predator-prey eddy. Meanwhile, 62% of bacteria production and 55% of Synechococcus spp. production are transported to higher trophic level (nanoflagellate), though the cascade effect might cause an underestimation of both percentages of transported carbon. Based on the increasing number of sizes we found in the size-fractionation experiments, we estimated that the predation values were underestimated by 28.3% for bacteria and 34.6% for Synechococcus spp. Taking these corrections into consideration, we conclude that picoplankton production is balanced by nonoflagellate grazing and the diet of nanoflagellate is composed of 64% bacteria and 36% Synechococcus spp.

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Deep Pelagic Ecosystem Dynamics in a Highly Impacted Water Column: The Gulf of Mexico After Deepwater Horizon

10.3389/978-2-88966-716-1 ◽

2021 ◽

Keyword(s):

Gulf Of Mexico ◽

Water Column ◽

Deepwater Horizon ◽

Ecosystem Dynamics ◽

Pelagic Ecosystem

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A perspective on billfish biological research and recommendations for the future

Marine and Freshwater Research ◽

10.1071/mf02072 ◽

2003 ◽

Vol 54 (4) ◽

pp. 343 ◽

Cited By ~ 9

Author(s):

Kim N. Holland

Keyword(s):

Ecosystem Dynamics ◽

Biological Research ◽

Great Promise ◽

Pelagic Ecosystem ◽

Short Term ◽

Pelagic Fishes ◽

In Captivity ◽

Electronic Tags ◽

Made In

A review of papers published on billfish biological research since the 1988 Billfish Symposium highlights the important role these symposia play in disseminating billfish research results and also shows that progress since 1988 has been slow, especially when compared with tuna and other pelagic fishes. One reason for the disparity is that marlin have not yet been successfully held in captivity. Progress has been made in elucidating the trophic biology of billfish and these data are helping to build models of pelagic ecosystem dynamics. The deployment of several types of electronic tags has expedited advances in understanding the short-term movements and depth distribution of billfish, but long-term tracks remain elusive. In part, this may be because insufficient effort has been directed at developing methods for restraining marlin for tag attachment or implantation. Light-based geolocation techniques show great promise for elucidating billfish movements, but appropriate scientific rigour must be applied to the publication of these data. Several suggestions for advancing billfish research are presented.

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Quality transformation of dissolved organic carbon during water transit through lakes: contrasting controls by photochemical and biological processes

10.5194/bg-2017-279 ◽

2017 ◽

Author(s):

Martin Berggren ◽

Marcus Klaus ◽

Balathandayuthabani Panneer Selvam ◽

Lena Ström ◽

Hjalmar Laudon ◽

...

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Heterotrophic Bacteria ◽

Field Studies ◽

Boreal Lakes ◽

Biological Processes ◽

Relative Importance ◽

In Situ Data ◽

Headwater Lakes ◽

Quality Transformation

Abstract. Dissolved organic carbon (DOC) may be removed, transformed or added during water transit through lakes, resulting in qualitative changes in DOC composition and pigmentation (color). However, the process-based understanding of these changes is incomplete, especially for headwater lakes. We hypothesized that because heterotrophic bacteria preferentially consume non-colored DOC, while photochemical processing remove colored fractions, the overall changes in DOC quality and color (absorbance) upon water passage through a lake depends on the relative importance of these two processes, accordingly. To test this hypothesis we combined laboratory experiments with field studies in nine boreal lakes, assessing both the relative importance of different DOC decay processes (biological or photo-chemical) and the loss of color during water transit time (WTT) through the lakes. We found that photo-chemistry qualitatively dominated the DOC transformation in the epilimnia of relatively clear headwater lakes, resulting in selective losses of colored DOC. However, in highly pigmented brown-water lakes (absorbance at 420 nm > 7 m−1) biological processes dominated, and there was no systematic relationship between color loss and WTT. Instead in situ data and dark experiments supported our hypothesis of selective microbial removal of non-pigmented DOC, mainly of low molecular weight, leading to persistent water color over time in these lakes. Our study shows that individual brown headwater lakes do not conform to the commonly reported pattern of selective removal of colored constituents in freshwaters, but rather the DOC shows a sustained degree of pigmentation upon transit through these lakes.

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Trophic state and microorganisms community of major sub-basins of the middle Rio Doce basin, southeast Brazil

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132005000500015 ◽

2005 ◽

Vol 48 (4) ◽

pp. 625-633 ◽

Cited By ~ 3

Author(s):

Mauricio Mello Petrucio ◽

Adriana Oliveira Medeiros ◽

Carlos Augusto Rosa ◽

Francisco Antônio Rodrigues Barbosa

Keyword(s):

Trophic State ◽

Heterotrophic Bacteria ◽

Total Alkalinity ◽

Phosphorus Concentration ◽

Total Phosphorus Concentration ◽

Temperature Conductivity ◽

Total N ◽

Southeast Brazil ◽

Minas Gerais State ◽

Total P

Total phosphorus concentration was used to define the trophic state of the main sub-basins of the middle Rio Doce, in Minas Gerais State (southeast Brazil) and physical, chemical, and microbiological variables of water were analyzed during 2000 to 2001. The study evaluated changes in water quality caused by seasonality and human activities. Water temperature, conductivity, pH, total alkalinity, dissolved oxygen, and concentrations of NH4-N, NO2-N, NO3-N, total-N, PO4-P, total-P, DOC, and chlorophyll-a were measured in seven rivers stretches (sampling stations). Total yeasts, faecal and total coliforms, and heterotrophic bacteria were also determined. The studied areas were considered to be under oligotrophic to eutrophic conditions. The variables that presented highest positive correlation with faecal coliforms were total-P and total-N, and heterotrophic bacteria density was identified as a good parameter to differentiate the ecosystems. These results suggested the inclusion of the trophic level and the distinct activities within a watershed as important elements when proposing conservation and restoration areas.

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