1
|
Doblin MA, Petrou K, Sinutok S, Seymour JR, Messer LF, Brown MV, Norman L, Everett JD, McInnes AS, Ralph PJ, Thompson PA, Hassler CS. Nutrient uplift in a cyclonic eddy increases diversity, primary productivity and iron demand of microbial communities relative to a western boundary current. PeerJ 2016; 4:e1973. [PMID: 27168982 PMCID: PMC4860325 DOI: 10.7717/peerj.1973] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/05/2016] [Indexed: 11/20/2022] Open
Abstract
The intensification of western boundary currents in the global ocean will potentially influence meso-scale eddy generation, and redistribute microbes and their associated ecological and biogeochemical functions. To understand eddy-induced changes in microbial community composition as well as how they control growth, we targeted the East Australian Current (EAC) region to sample microbes in a cyclonic (cold-core) eddy (CCE) and the adjacent EAC. Phototrophic and diazotrophic microbes were more diverse (2–10 times greater Shannon index) in the CCE relative to the EAC, and the cell size distribution in the CCE was dominated (67%) by larger micro-plankton \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{upgreek}
\usepackage{mathrsfs}
\setlength{\oddsidemargin}{-69pt}
\begin{document}
}{}$(\geq 20\lrm{\mu }\mathrm{m})$\end{document}≥20μm, as opposed to pico- and nano-sized cells in the EAC. Nutrient addition experiments determined that nitrogen was the principal nutrient limiting growth in the EAC, while iron was a secondary limiting nutrient in the CCE. Among the diazotrophic community, heterotrophic NifH gene sequences dominated in the EAC and were attributable to members of the gamma-, beta-, and delta-proteobacteria, while the CCE contained both phototrophic and heterotrophic diazotrophs, including Trichodesmium, UCYN-A and gamma-proteobacteria. Daily sampling of incubation bottles following nutrient amendment captured a cascade of effects at the cellular, population and community level, indicating taxon-specific differences in the speed of response of microbes to nutrient supply. Nitrogen addition to the CCE community increased picoeukaryote chlorophyll a quotas within 24 h, suggesting that nutrient uplift by eddies causes a ‘greening’ effect as well as an increase in phytoplankton biomass. After three days in both the EAC and CCE, diatoms increased in abundance with macronutrient (N, P, Si) and iron amendment, whereas haptophytes and phototrophic dinoflagellates declined. Our results indicate that cyclonic eddies increase delivery of nitrogen to the upper ocean to potentially mitigate the negative consequences of increased stratification due to ocean warming, but also increase the biological demand for iron that is necessary to sustain the growth of large-celled phototrophs and potentially support the diversity of diazotrophs over longer time-scales.
Collapse
Affiliation(s)
- Martina A Doblin
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney , Ultimo NSW , Australia
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney , Ultimo NSW , Australia
| | - Sutinee Sinutok
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo NSW, Australia; Faculty of Environmental Management, Prince of Songkla University, Kho Hong Songkhla, Thailand
| | - Justin R Seymour
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney , Ultimo NSW , Australia
| | - Lauren F Messer
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney , Ultimo NSW , Australia
| | - Mark V Brown
- School of Biotechnology and Biomolecular Sciences, University of New South Wales , Sydney NSW , Australia
| | - Louiza Norman
- Department of Plant Sciences, University of Cambridge , Cambridge , United Kingdom
| | - Jason D Everett
- School of Biological, Earth and Environmental Sciences, University of New South Wales , Sydney NSW , Australia
| | - Allison S McInnes
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney , Ultimo NSW , Australia
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney , Ultimo NSW , Australia
| | - Peter A Thompson
- Oceans and Atmosphere Flagship, Commonwealth Scientific Industrial Research Organisation , Hobart Tas , Australia
| | - Christel S Hassler
- Institute F.-A. Forel, Earth and Environmental Sciences, University of Geneva , Geneva , Switzerland
| |
Collapse
|
2
|
Stocks JR, Gray CA, Taylor MD. Intra-population trends in the maturation and reproduction of a temperate marine herbivore Girella elevata across latitudinal clines. JOURNAL OF FISH BIOLOGY 2015; 86:463-483. [PMID: 25613077 DOI: 10.1111/jfb.12563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 09/25/2014] [Indexed: 06/04/2023]
Abstract
Latitudinal variation in the reproductive characteristics of a temperate marine herbivore, rock blackfish Girella elevata, was examined from three regions of the south-eastern Australian coast. Biological sampling covered 780 km of coastline, including the majority of the species distribution. The sampling range incorporated three distinct oceanographic regions of the East Australian Current, a poleward-flowing western boundary current of the Southern Pacific Gyre and climate-change hotspot. Girella elevata are a highly fecund, group synchronous (multiple batch)-spawner. Mean fork length (LF ) and age at maturity were greater for females than males within all regions, with both male and female G. elevata of the southern region maturing at a greater size and age than those from the central region. Estimates of batch fecundity (FB ) were greatest in the northern and southern regions, relative to the central region where growth rates were greatest. Significant positive relationships were observed between FB and LF , and FB and total fish mass. Gonado-somatic indices indicated latitudinal synchrony in spawning seasonality between G. elevata at higher latitudes, spawning in the late austral spring and summer. A late or prolonged spawning period is evident for G. elevata from the northern region. Juvenile recruitment to intertidal rock pools within the central and southern regions was synchronous with the spawning season, however, no juveniles were found within the northern region. The implications of latitudinal variation in reproductive characteristics are discussed in the context of climate and oceanographic conditions of south-east Australia.
Collapse
Affiliation(s)
- J R Stocks
- School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Batemans Bay Fisheries Centre, P. O. Box 17, Batemans Bay, NSW 2536, Australia
| | - C A Gray
- School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- WildFish Research, Grays Point, Sydney, NSW 2232, Australia
| | - M D Taylor
- School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Port Stephens Fisheries Institute, Fisheries NSW, Locked Bag 1, Nelson Bay, NSW 2316, Australia
| |
Collapse
|
3
|
Coleman MA, Feng M, Roughan M, Cetina-Heredia P, Connell SD. Temperate shelf water dispersal by Australian boundary currents: Implications for population connectivity. ACTA ACUST UNITED AC 2013. [DOI: 10.1215/21573689-2409306] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
4
|
Everett JD, Baird ME, Suthers IM. Three-dimensional structure of a swarm of the salpThalia democraticawithin a cold-core eddy off southeast Australia. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jc007310] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
5
|
Benson SR, Eguchi T, Foley DG, Forney KA, Bailey H, Hitipeuw C, Samber BP, Tapilatu RF, Rei V, Ramohia P, Pita J, Dutton PH. Large-scale movements and high-use areas of western Pacific leatherback turtles,Dermochelys coriacea. Ecosphere 2011. [DOI: 10.1890/es11-00053.1] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
6
|
Oliveira LR, Piola AR, Mata MM, Soares ID. Brazil Current surface circulation and energetics observed from drifting buoys. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jc004900] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|