Modelling marine diseases

The unique characteristics of marine ecosystems have pushed investigators to refine well-tested and widely applied epidemiological modeling methods to understand marine disease dynamics. This chapter begins by reviewing models used to quantify within-host parasite dynamics in open marine ecosystems where infection is near universal. These models are powerful tools for quantifying how diseases respond to changing environmental conditions and, when reliable environmental data are available, can forecast marine disease risks into the future. This chapter then describes epidemiological models that consider transmission processes and parasite life histories unique to marine systems, and then incorporates disease processes in fisheries assessment models. Finally, because disease dynamics vary across local host populations, this chapter concludes by overviewing ocean circulation models and their use in understanding parasite dispersal and spread in marine ecosystems.

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Host–Parasite Relationships and Life Histories of Trypanosomes in Australia

Advances in Parasitology ◽

10.1016/bs.apar.2016.06.001 ◽

2017 ◽

pp. 47-109 ◽

Cited By ~ 12

Author(s):

C. Cooper ◽

P.L. Clode ◽

C. Peacock ◽

R.C.A. Thompson

Keyword(s):

Life Histories ◽

Host Parasite

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Community-Level Interactions and Disease Dynamics

10.1093/oso/9780198746249.003.0008 ◽

2021 ◽

pp. 145-170

Author(s):

Karen D. McCoy

Keyword(s):

Local Area ◽

Community Level ◽

Disease Dynamics ◽

Biological Communities ◽

Natural Systems ◽

Parasite Communities ◽

Almost All ◽

Host Parasite ◽

Natural Communities ◽

Over Time

An ecological community includes all individuals of all species that interact within a single patch or local area of habitat. Understanding the outcome of host–parasite interactions and predicting disease dynamics is particularly challenging at this biological scale because the different component species interact both directly and indirectly in complex ways. Current shifts in biodiversity due to global change, and its associated modifications to biological communities, will alter these interactions, including the probability of disease emergence, its dynamics over time, and its community-level consequences. Birds are integral component species of almost all natural communities. Due to their ubiquity and specific life history traits, they are defining actors in the ecology, evolution, and epidemiology of parasitic species. To better understand this role, this chapter examines the relative importance of birds and parasites in natural communities, revisiting basic notions in community ecology. The impact of changes in diversity for disease dynamics, including the debate surrounding dilution and amplification effects are specifically addressed. By considering the intrinsic complexities of natural communities, the importance of combining data from host and parasite communities to better understand how natural systems function over time and space is highlighted. The different elements in each section of the chapter are illustrated with brief, concrete examples from avian species, with a detailed example from marine bird communities in which Lyme disease bacteria circulate.

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Laboulbeniomycetes: Intimate Fungal Associates of Arthropods

Annual Review of Entomology ◽

10.1146/annurev-ento-013020-013553 ◽

2021 ◽

Vol 66 (1) ◽

pp. 257-276 ◽

Cited By ~ 2

Author(s):

Danny Haelewaters ◽

Meredith Blackwell ◽

Donald H. Pfister

Keyword(s):

Population Biology ◽

Life Histories ◽

Invasion Biology ◽

Species Discovery ◽

Phylogenetic Studies ◽

Intimate Association ◽

Red Algal ◽

Molecular Phylogenetic ◽

Parasitic Worms ◽

Host Parasite

Arthropod–fungus interactions involving the Laboulbeniomycetes have been pondered for several hundred years. Early studies of Laboulbeniomycetes faced several uncertainties. Were they parasitic worms, red algal relatives, or fungi? If they were fungi, to which group did they belong? What was the nature of their interactions with their arthropod hosts? The historical misperceptions resulted from the extraordinary morphological features of these oddly constructed ectoparasitic fungi. More recently, molecular phylogenetic studies, in combination with a better understanding of life histories, have clearly placed these fungi among filamentous Ascomycota (subphylum Pezizomycotina). Species discovery and research on the classification of the group continue today as arthropods, and especially insects, are routinely collected and examined for the presence of Laboulbeniomycetes. Newly armed with molecular methods, mycologists are poisedto use Laboulbeniomycetes–insect associations as models for the study of a variety of basic evolutionary and ecological questions involving host–parasite relationships, modes of nutrient intake, population biology, host specificity, biological control, and invasion biology. Collaboration between mycologists and entomologists is essential to successfully advance knowledge of Laboulbeniomycetes and their intimate association with their hosts.

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Coevolutionary interactions between host life histories and parasite life cycles

Parasitology ◽

10.1017/s0031182000084936 ◽

1998 ◽

Vol 116 (S1) ◽

pp. S47-S55 ◽

Cited By ~ 26

Author(s):

J. C. Koella ◽

P. Agnew ◽

Y. Michalakis

Keyword(s):

Life History ◽

Life Cycle ◽

Life Histories ◽

Life History Traits ◽

Evolutionary Ecology ◽

Life Cycles ◽

Microsporidian Parasite ◽

History Of ◽

Host Life ◽

Host Parasite

SummarySeveral recent studies have discussed the interaction of host life-history traits and parasite life cycles. It has been observed that the life-history of a host often changes after infection by a parasite. In some cases, changes of host life-history traits reduce the costs of parasitism and can be interpreted as a form of resistance against the parasite. In other cases, changes of host life-history traits increase the parasite's transmission and can be interpreted as manipulation by the parasite. Alternatively, changes of host's life-history traits can also induce responses in the parasite's life cycle traits. After a brief review of recent studies, we treat in more detail the interaction between the microsporidian parasite Edhazardia aedis and its host, the mosquito Aedes aegypti. We consider the interactions between the host's life-history and parasite's life cycle that help shape the evolutionary ecology of their relationship. In particular, these interactions determine whether the parasite is benign and transmits vertically or is virulent and transmits horizontally.Key words: host-parasite interaction, life-history, life cycle, coevolution.

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Ten-year projection of white-nose syndrome disease dynamics at the southern leading-edge of infection in North America

10.1101/2020.11.12.379271 ◽

2020 ◽

Author(s):

Melissa B. Meierhofer ◽

Thomas M. Lilley ◽

Lasse Ruokolainen ◽

Joseph S. Johnson ◽

Steven Parratt ◽

...

Keyword(s):

Infectious Disease ◽

North America ◽

Environmental Conditions ◽

Leading Edge ◽

Environmental Data ◽

Disease Spread ◽

Disease Dynamics ◽

Pseudogymnoascus Destructans ◽

White Nose Syndrome ◽

Management Actions

AbstractPredicting the emergence and spread of infectious diseases is critical for effective conservation of biodiversity. White-nose syndrome (WNS), an emerging infectious disease of bats, has resulted in high mortality in eastern North America. Because the fungal causative agent Pseudogymnoascus destructans is constrained by temperature and humidity, spread dynamics may vary greatly by geography. Environmental conditions in the southern part of the continent, where disease dynamics are typically studied, making it difficult to predict how the disease will manifest. Herein, we modeled the spread of WNS in Texas based on available cave densities and average dispersal distances of species occupying these sites, and projected these results out to 10 years. We parameterized a predictive model of WNS epidemiology and its effects on hibernatory bat populations with observed environmental data from bat hibernation sites in Texas. Our model suggests that bat populations in northern Texas will be more affected by WNS mortality than southern Texas. As such, we recommend prioritizing the preservation of large overwintering colonies of bats in north Texas through management actions. Our model further illustrates that infectious disease spread and infectious disease severity can become uncoupled over a gradient of environmental variation. Finally, our results highlight the importance of understanding host, pathogen and environmental conditions in various settings to elucidate what may happen across a breadth of environments.

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Utilizing sponge spicules in taxonomic, ecological and environmental reconstructions: a review

PeerJ ◽

10.7717/peerj.10601 ◽

2020 ◽

Vol 8 ◽

pp. e10601

Author(s):

Magdalena Łukowiak

Keyword(s):

Ocean Circulation ◽

Environmental Data ◽

Silicon Isotope ◽

Structural Elements ◽

Climate Conditions ◽

The Past ◽

Sponge Spicules ◽

Silica Cycle ◽

Taxonomic Assignments ◽

Water Depths

Most sponges produce skeletons formed by spicules, structural elements that develop in a wide variety of sizes and tridimensional shapes. The morphologies of spicules are often unique to clade- or even species-level taxa which makes them particularly useful in taxonomic assignments. When dead sponge bodies disintegrate, spicules become incorporated into sediments and sometimes accumulate into enormous agglomerations called spicule mats or beds, or fossilize to form special type of rocks called the spiculites. The record of fossil and subfossil sponge spicules is extraordinarily rich and often serves as a basis for far-reaching reconstructions of sponge communities, though spicules are also bearers of significant ecological and environmental information. Specific requirements and preferences of sponges can be used to interpret the environment in which they lived, and reconstruct oscillations in water depths, pH, temperatures, and other parameters, providing snapshots of past climate conditions. In turn, the silicon isotope compositions in spicules (δ30Si) are being increasingly often used to estimate the level of silicic acid in the marine settings throughout the geological history, which enables to reconstruct the past silica cycle and ocean circulation. This contribution provides a review of the use of sponge spicules in reconstructions of sponge communities, their ecology, and environments, and aims to detect the pertinent gaps in their utilization. Even though spicules are well known for their significance as bearers of taxonomic, ecological, and environmental data, their potential remains to be fully exploited.

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Use of Foraminifera in Climate Science

Oxford Research Encyclopedia of Climate Science ◽

10.1093/acrefore/9780190228620.013.735 ◽

2019 ◽

Author(s):

Gerhard Schmiedl

Keyword(s):

Stable Isotope ◽

Trace Element ◽

Ocean Circulation ◽

Transfer Functions ◽

Isotope Composition ◽

Sediment Cores ◽

Environmental Data ◽

Geochemical Data ◽

Climate History ◽

Sediment Types

The understanding of past changes in climate and ocean circulation is to a large extent based on information from marine sediments. Marine deposits contain a variety of microfossils, which archive (paleo)-environmental information, both in their floral and faunal assemblages and in their stable isotope and trace element compositions. Sampling campaigns in the late 19th and early 20th centuries were dedicated to the inventory of sediment types and microfossil taxa. With the initiation of various national and international drilling programs in the second half of the 20th century, sediment cores were systematically recovered from all ocean basins and since then have shaped our knowledge of the oceans and climate history. The stable oxygen isotope composition of foraminiferal tests from the sediment cores delivered a continuous record of late Cretaceous–Cenozoic glaciation history. This record impressively proved the effects of periodic changes in the orbital configuration of the Earth on climate on timescales of tens to hundreds of thousands of years, described as Milankovitch cycles. Based on the origination and extinction patterns of marine microfossil groups, biostratigraphic schemes have been established, which are readily used for the dating of sediment successions. The species composition of assemblages of planktic microfossils, such as planktic foraminifera, radiolarians, dinoflagellates, coccolithophorids, and diatoms, is mainly related to sea-surface temperature and salinity but also to the distribution of nutrients and sea ice. Benthic microfossil groups, in particular benthic foraminifera but also ostracods, respond to changes in water depth, oxygen, and food availability at the sea floor, and provide information on sea-level changes and benthic-pelagic coupling in the ocean. The establishment and application of transfer functions delivers quantitative environmental data, which can be used in the validation of results from ocean and climate modeling experiments. Progress in analytical facilities and procedures allows for the development of new proxies based on the stable isotope and trace element composition of calcareous, siliceous, and organic microfossils. The combination of faunal and geochemical data delivers information on both environmental and biotic changes from the same sample set. Knowledge of the response of marine microorganisms to past climate changes at various amplitudes and pacing serves as a basis for the assessment of future resilience of marine ecosystems to the anticipated impacts of global warming.

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Parasites in space and time: a novel method to assess and illustrate host-searching behaviour of trematode cercariae

Parasitology ◽

10.1017/s0031182018000288 ◽

2018 ◽

Vol 145 (11) ◽

pp. 1469-1474 ◽

Cited By ~ 5

Author(s):

Christian Selbach ◽

Robert Poulin

Keyword(s):

Life Histories ◽

Parasite Community ◽

Video Tracking ◽

Trematode Species ◽

Host Searching ◽

Novel Method ◽

The Individual ◽

Individual Strategies ◽

Host Parasite ◽

Automated Video Tracking

AbstractThe transmission from one host to another constitutes a challenging obstacle for parasites and is a key determinant of their fitness. Due to their complex life histories involving several different hosts, the free-living dispersal stages (cercariae) of digenean trematodes show a huge diversity in morphology and behaviour. On a finer scale, we still have an extremely limited understanding of the inter- and intraspecific variation in transmission strategies of many trematode species. Here, we present a novel method to study the movement patterns of cercariae of four New Zealand trematode species (Coitocaecum parvum, Maritrema poulini, Apatemon sp. and Aporocotylid sp. I.) via automated video tracking. This approach allows to quantify parameters otherwise not measurable and clearly illustrates the individual strategies of parasites to search for their respective target hosts. Cercariae that seek out an evasive fish target hosts showed higher swimming speeds (acceleration and velocity) and travelled further distances, compared with species searching for high-density crustacean hosts. Automated video tracking provides a powerful tool for such detailed analyses of parasites’ host-searching strategies and can enhance our understanding of complex host–parasite interactions, ranging from parasite community structure to the transmission of potential disease agents.

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Mapping near surface global marine ecosystems through cluster analysis of environmental data

Ecological Research ◽

10.1111/1440-1703.12060 ◽

2020 ◽

Vol 35 (2) ◽

pp. 327-342 ◽

Cited By ~ 1

Author(s):

Qianshuo Zhao ◽

Zeenatul Basher ◽

Mark J. Costello

Keyword(s):

Cluster Analysis ◽

Marine Ecosystems ◽

Environmental Data ◽

Near Surface

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Toward an improved characterisation of climate and environmental changes during warm periods of the past: First results from the MOPGA HOTCLIM project

10.5194/egusphere-egu21-12932 ◽

2021 ◽

Author(s):

Etienne Legrain ◽

Emilie Capron ◽

Frederic Parrenin

Keyword(s):

Carbon Cycle ◽

Ocean Circulation ◽

Environmental Changes ◽

Temporal Structure ◽

Ice Cores ◽

Environmental Data ◽

Interglacial Period ◽

Climate Projections ◽

The Past ◽

First Results

The current and future anthropogenic-induced high-latitude warming will have global climatic implications due to polar ice mass loss, sea level rise and ocean circulation changes. However, uncertainty remains on future climate projections mainly due to an incomplete understanding of climate, cryosphere and carbon cycle feedback processes occurring at centennial to millennial- timescales. Progress can be achieved by exploring climate and environmental changes that occurred in the past. In the HOTCLIM project, we are studying past warm periods, also referred to as interglacials, which exhibit a polar warming comparable to that projected by 2100 due to specific combinations of orbital and CO2 forcing. Especially, we are investigating the link between the carbon cycle dynamics and climate changes. To do so, we are combining (i) new analyses on the air trapped in Antarctic deep ice cores to inform on past changes in Antarctic climate and atmospheric CO2 concentrations (ii) climate and environmental data synthesis looking into the lower latitudes using terrestrial and oceanic archives (sea surface temperature, hydrological cycles, ocean circulation) (iii) an evaluation of outputs from climate models using the new comparison of the paleoclimatic datasynthesis and models output. The HOTCLIM project will improve our understanding of the natural climate variability and the processes involved during past periods associated with temperature changes comparable to projected future warming, hence helping improve climate projectionsHere, we present the first results from the HOTCLIM project which is a multi-archive synthesis focused on the warm interval occurring between 190 and 243 ka BP, also refered to as Marine Isotopic Stage 7 (MIS 7). This warm period is of special interest because it follows the fastest transition between a cold (glacial) and a hot (interglacial) period of the last 800&#160;000 ka, with a polar warming of 10 degrees in less than 5ka. We have compiled more than 30 oceanic cores, 9 speleothems and 3 ice cores covering the MIS 7 period. To compare them, we are now building a common chronology to these records. The use of combined continental (ice cores, speleothems) and oceanic (sediment cores) archives located on the whole surface of the Earth will allows to characterize (i) the amplitude and the temporal structure of the surface warming across the globe (ii) the contrast between oceanic and continental warming.

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