An approach to analyzing spatial patterns in annual dynamics of planktonic ciliate communities and their environmental drivers in marine ecosystems

AbstractAll pathogens are heterogeneous in space, yet little is known about the prevalence and scale of this spatial variation, particularly in wild animal systems. To address this question, we conducted a broad literature search to identify datasets involving diseases of wild mammals in spatially distributed contexts. Across 31 such final datasets featuring 89 replicates and 71 host-parasite combinations, only 51% had previously been used to test spatial hypotheses. We analysed these datasets for spatial dependence within a standardised modelling framework using Bayesian linear models. We detected spatial autocorrelation in 44/89 model replicates (54%) across 21/31 datasets (68%), spread across parasites of all groups and transmission modes. Surprisingly, although larger sampling areas more easily detected spatial patterns, even some very small study areas (under 0.01km2) exhibited substantial spatial heterogeneity. Parasites of all transmission modes had easily detectable spatial patterns, implying that structured contact networks and susceptibility effects are likely as important in spatially structuring disease as are environmental drivers of transmission efficiency. Our findings imply that fine-scale spatial patterns of infection often manifest in wild animal systems, whether or not the aim of the study is to examine environmentally varying processes. Given the widespread nature of these findings, studies should more frequently record and analyse spatial data, facilitating development and testing of spatial hypotheses in disease ecology.

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Ocean-related global change alters lipid biomarker production in common marine phytoplankton

10.5194/bg-2020-183 ◽

2020 ◽

Author(s):

Rong Bi ◽

Stefanie M. H. Ismar-Rebitz ◽

Ulrich Sommer ◽

Hailong Zhang ◽

Meixun Zhao

Keyword(s):

Fatty Acids ◽

Global Change ◽

Carbon Allocation ◽

Marine Ecosystems ◽

Lipid Biomarkers ◽

Marine Phytoplankton ◽

Environmental Drivers ◽

High Pco2 ◽

P Deficiency ◽

Lipid Biomarker

Abstract. Global change concurrently alters multiple environmental factors, with uncertain consequences for marine ecosystems. Lipids, in their function as trophic markers in food webs and organic matter source indicators in water column and sediments, provide a tool for reconstructing the complexity of global change effects. It remains unclear how ongoing changes in multiple environmental drivers affect the production of key lipid biomarkers in marine phytoplankton. Here, we tested the responses of sterols, alkenones and fatty acids (FAs) in the diatom Phaeodactylum tricornutum, the cryptophyte Rhodomonas sp. and the haptophyte Emiliania huxleyi under a full-factorial combination of three temperatures (12, 18 and 24 °C), three N : P supply ratios (molar ratios 10 : 1, 24 : 1 and 63 : 1) and two pCO2 levels (560 and 2400 µatm) in semi-continuous culturing experiments. Overall, N and P deficiency had a stronger effect on per-cell contents of sterols, alkenones and FAs than warming and enhanced pCO2. Specifically, P deficiency caused an overall increase in biomarker production in most cases, while N deficiency, warming and high pCO2 caused non-systematic changes. Under future ocean scenarios, we predict an overall decrease in carbon-normalized contents of sterols and polyunsaturated fatty acids (PUFAs) in E. huxleyi and P. tricornutum, and a decrease in sterols but an increase in PUFAs in Rhodomonas sp. Variable contents of lipid biomarkers indicate a diverse carbon allocation between marine phytoplankton species in response to changing environments. Thus, it is necessary to consider the changes in key lipids and their consequences for food web dynamics and biogeochemical cycles, when predicting the influence of global change on marine ecosystems.

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Bacterial and archaeal spatial distribution and its environmental drivers in an extremely haloalkaline soil at the landscape scale

PeerJ ◽

10.7717/peerj.6127 ◽

2019 ◽

Vol 7 ◽

pp. e6127 ◽

Cited By ~ 2

Author(s):

Martha Adriana Martínez-Olivas ◽

Norma G. Jiménez-Bueno ◽

Juan Alfredo Hernández-García ◽

Carmine Fusaro ◽

Marco Luna-Guido ◽

...

Keyword(s):

Community Structure ◽

Spatial Patterns ◽

Environmental Gradients ◽

Alpha Diversity ◽

Archaeal Community ◽

Physicochemical Characteristics ◽

Soil Characteristics ◽

Environmental Drivers ◽

Bacterial Phyla ◽

Geostatistical Techniques

Background A great number of studies have shown that the distribution of microorganisms in the soil is not random, but that their abundance changes along environmental gradients (spatial patterns). The present study examined the spatial variability of the physicochemical characteristics of an extreme alkaline saline soil and how they controlled the archaeal and bacterial communities so as to determine the main spatial community drivers. Methods The archaeal and bacterial community structure, and soil characteristics were determined at 13 points along a 211 m transect in the former lake Texcoco. Geostatistical techniques were used to describe spatial patterns of the microbial community and soil characteristics and determine soil properties that defined the prokaryotic community structure. Results A high variability in electrolytic conductivity (EC) and water content (WC) was found. Euryarchaeota dominated Archaea, except when the EC was low. Proteobacteria, Bacteroidetes and Actinobacteria were the dominant bacterial phyla independent of large variations in certain soil characteristics. Multivariate analysis showed that soil WC affected the archaeal community structure and a geostatistical analysis found that variation in the relative abundance of Euryarchaeota was controlled by EC. The bacterial alpha diversity was less controlled by soil characteristics at the scale of this study than the archaeal alpha diversity. Discussion Results indicated that WC and EC played a major role in driving the microbial communities distribution and scale and sampling strategies were important to define spatial patterns.

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Microbial Colonization in Marine Environments: Overview of Current Knowledge and Emerging Research Topics

Journal of Marine Science and Engineering ◽

10.3390/jmse8020078 ◽

2020 ◽

Vol 8 (2) ◽

pp. 78 ◽

Cited By ~ 8

Author(s):

Gabriella Caruso

Keyword(s):

Microbial Communities ◽

Environmental Changes ◽

Current Knowledge ◽

Cell Communication ◽

Marine Ecosystems ◽

Microbial Colonization ◽

Artificial Substrates ◽

Environmental Drivers ◽

Future Research ◽

Microbial Biofilms

Microbial biofilms are biological structures composed of surface-attached microbial communities embedded in an extracellular polymeric matrix. In aquatic environments, the microbial colonization of submerged surfaces is a complex process involving several factors, related to both environmental conditions and to the physical-chemical nature of the substrates. Several studies have addressed this issue; however, more research is still needed on microbial biofilms in marine ecosystems. After a brief report on environmental drivers of biofilm formation, this study reviews current knowledge of microbial community attached to artificial substrates, as obtained by experiments performed on several material types deployed in temperate and extreme polar marine ecosystems. Depending on the substrate, different microbial communities were found, sometimes highlighting the occurrence of species-specificity. Future research challenges and concluding remarks are also considered. Emphasis is given to future perspectives in biofilm studies and their potential applications, related to biofouling prevention (such as cell-to-cell communication by quorum sensing or improved knowledge of drivers/signals affecting biological settlement) as well as to the potential use of microbial biofilms as sentinels of environmental changes and new candidates for bioremediation purposes.

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Production of mobile invertebrate communities on shallow reefs from temperate to tropical seas

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1798 ◽

2020 ◽

Vol 287 (1941) ◽

pp. 20201798

Author(s):

K. M. Fraser ◽

J. S. Lefcheck ◽

S. D. Ling ◽

C. Mellin ◽

R. D. Stuart-Smith ◽

...

Keyword(s):

Primary Productivity ◽

Human Impacts ◽

Anthropogenic Impacts ◽

Selection Procedure ◽

Marine Ecosystems ◽

Environmental Drivers ◽

Kelp Forests ◽

Food Web Structure ◽

Continental Scale ◽

Biogenic Habitat

Primary productivity of marine ecosystems is largely driven by broad gradients in environmental and ecological properties. By contrast, secondary productivity tends to be more variable, influenced by bottom-up (resource-driven) and top-down (predatory) processes, other environmental drivers, and mediation by the physical structure of habitats. Here, we use a continental-scale dataset on small mobile invertebrates (epifauna), common on surfaces in all marine ecosystems, to test influences of potential drivers of temperature-standardized secondary production across a large biogeographic range. We found epifaunal production to be remarkably consistent along a temperate to tropical Australian latitudinal gradient of 28.6°, spanning kelp forests to coral reefs (approx. 3500 km). Using a model selection procedure, epifaunal production was primarily related to biogenic habitat group, which explained up to 45% of total variability. Production was otherwise invariant to predictors capturing primary productivity, the local biomass of fishes (proxy for predation pressure), and environmental, geographical, and human impacts. Highly predictable levels of epifaunal productivity associated with distinct habitat groups across continental scales should allow accurate modelling of the contributions of these ubiquitous invertebrates to coastal food webs, thus improving understanding of likely changes to food web structure with ocean warming and other anthropogenic impacts on marine ecosystems.

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