LIVIVO - Search results -

Search results

Result 1 - 10 of total 42

Search options

Article ; Online: Cross‐depth connectivity shows that deep kelps may act as refugia by reseeding climate‐vulnerable shallow beds

Anita Giraldo Ospina / Leonardo Ruiz‐Montoya / Gary A. Kendrick / Renae K. Hovey

Ecosphere, Vol 14, Iss 3, Pp n/a-n/a (2023)

2023

Abstract: Abstract Refugia are habitats where species can survive or retreat to during environmental disturbances. One key assumption of habitats that constitute refugia is that they may assist in the persistence of impacted populations through the provision of ... ...

Abstract	Abstract Refugia are habitats where species can survive or retreat to during environmental disturbances. One key assumption of habitats that constitute refugia is that they may assist in the persistence of impacted populations through the provision of reproductive propagules. This “reseeding” hypothesis assumes that demographic connectivity exists between refugia and impacted habitats. We tested this hypothesis for the kelp Ecklonia radiata, a temperate marine foundation species dominant in the temperate coast of Australia. Our study site was the coast of Western Australia, a system where deep habitats are considered to act as refugia for their shallow counterparts, yet, for which estimations of population connectivity have overlooked propagule dispersal across depth. Here, we simulated the dominant ocean circulation conditions in a three‐dimensional oceanographic model and the dispersal of kelp propagules by incorporating physical properties of zoospores within the model. The trajectories of kelp propagules were tracked and analyzed to identify their probability of settlement within the domain of the study. Measurements of kelp fecundity across depth were obtained within the study region, and used to estimate zoospore settlement densities. Here, we show that deep populations of E. radiata have the capacity to supply zoospores to shallow reefs. Our results show that zoospores released at deeper beds (40 m of depth) are transported to shallow reefs (<20 m of depth) and that settlement densities are sufficient to drive kelp fertilization. Analysis of particle exchange among depths also indicates that mid‐depth reefs (~25 m of depth) act as important “stepping stones” for cross‐depth connectivity, enhancing dispersal between the shallowest and deepest locations, which is especially important when reefs of different depths are separated by tens of kilometers. We show that after an environmental disturbance, persistent deep kelps may act as refugia by sourcing propagules and reseeding impacted shallow reefs, ...
Keywords	across‐shore dispersal ; deep refugia ; Ecklonia radiata ; fecundity ; particle tracking ; settlement densities ; Ecology ; QH540-549.5
Subject code	551
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Historic and contemporary biogeographic perspectives on range‐wide spatial genetic structure in a widespread seagrass

Elizabeth A. Sinclair / Renae K. Hovey / Siegfried L. Krauss / Janet M. Anthony / Michelle Waycott / Gary A. Kendrick

Ecology and Evolution, Vol 13, Iss 3, Pp n/a-n/a (2023)

2023

Abstract: Abstract Historical and contemporary processes drive spatial patterns of genetic diversity. These include climate‐driven range shifts and gene flow mediated by biogeographical influences on dispersal. Assessments that integrate these drivers are uncommon, ...

Abstract	Abstract Historical and contemporary processes drive spatial patterns of genetic diversity. These include climate‐driven range shifts and gene flow mediated by biogeographical influences on dispersal. Assessments that integrate these drivers are uncommon, but critical for testing biogeographic hypotheses. Here, we characterize intraspecific genetic diversity and spatial structure across the entire distribution of a temperate seagrass to test marine biogeographic concepts for southern Australia. Predictive modeling was used to contrast the current Posidonia australis distribution to its historical distribution during the Last Glacial Maximum (LGM). Spatial genetic structure was estimated for 44 sampled meadows from across the geographical range of the species using nine microsatellite loci. Historical and contemporary distributions were similar, with the exception of the Bass Strait. Genetic clustering was consistent with the three currently recognized biogeographic provinces and largely consistent with the finer‐scale IMCRA bioregions. Discrepancies were found within the Flindersian province and southwest IMCRA bioregion, while two regions of admixture coincided with transitional IMCRA bioregions. Clonal diversity was highly variable but positively associated with latitude. Genetic differentiation among meadows was significantly associated with oceanographic distance. Our approach suggests how shared seascape drivers have influenced the capacity of P. australis to effectively track sea level changes associated with natural climate cycles over millennia, and in particular, the recolonization of meadows across the Continental Shelf following the LGM. Genetic structure associated with IMCRA bioregions reflects the presence of stable biogeographic barriers, such as oceanic upwellings. This study highlights the importance of biogeography to infer the role of historical drivers in shaping extant diversity and structure.
Keywords	IMCRA bioregions ; marine biogeography ; microsatellite DNA ; population genetics ; Posidonia australis ; predictive distribution modeling ; Ecology ; QH540-549.5
Subject code	590
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Ocean connectivity and habitat characteristics predict population genetic structure of seagrass in an extreme tropical setting

Udhi E. Hernawan / Kor‐jent vanDijk / Gary A. Kendrick / Ming Feng / Oliver Berry / Christopher Kavazos / Kathryn McMahon

Ecology and Evolution, Vol 13, Iss 7, Pp n/a-n/a (2023)

2023

Abstract: Abstract Understanding patterns of gene flow and processes driving genetic differentiation is important for a broad range of conservation practices. In marine organisms, genetic differentiation among populations is influenced by a range of spatial, ... ...

Abstract	Abstract Understanding patterns of gene flow and processes driving genetic differentiation is important for a broad range of conservation practices. In marine organisms, genetic differentiation among populations is influenced by a range of spatial, oceanographic, and environmental factors that are attributed to the seascape. The relative influences of these factors may vary in different locations and can be measured using seascape genetic approaches. Here, we applied a seascape genetic approach to populations of the seagrass, Thalassia hemprichii, at a fine spatial scale (~80 km) in the Kimberley coast, western Australia, a complex seascape with strong, multidirectional currents greatly influenced by extreme tidal ranges (up to 11 m, the world's largest tropical tides). We incorporated genetic data from a panel of 16 microsatellite markers, overwater distance, oceanographic data derived from predicted passive dispersal on a 2 km‐resolution hydrodynamic model, and habitat characteristics from each meadow sampled. We detected significant spatial genetic structure and asymmetric gene flow, in which meadows 12–14 km apart were less connected than ones 30–50 km apart. This pattern was explained by oceanographic connectivity and differences in habitat characteristics, suggesting a combined scenario of dispersal limitation and facilitation by ocean current with local adaptation. Our findings add to the growing evidence for the key role of seascape attributes in driving spatial patterns of gene flow. Despite the potential for long‐distance dispersal, there was significant genetic structuring over small spatial scales implicating dispersal and recruitment bottlenecks and highlighting the importance of implementing local‐scale conservation and management measures.
Keywords	extreme tidal range ; gene flow ; local adaptation ; oceanographic connectivity ; seascape genetics ; Thalassia hemprichii ; Ecology ; QH540-549.5
Subject code	333
Language	English
Publishing date	2023-07-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Composition of Seagrass Root Associated Bacterial Communities Are Linked to Nutrients and Heavy Metal Concentrations in an Anthropogenically Influenced Estuary

Belinda C. Martin / Jen A. Middleton / Grzegorz Skrzypek / Gary A. Kendrick / Jeff Cosgrove / Matthew W. Fraser

Frontiers in Marine Science, Vol

2022 Volume 8

Abstract: Seagrasses are globally recognized as bioindicators of marine eutrophication and contamination. Seagrasses also harbor a distinct root microbial community that largely reflects the conditions of the surrounding environment as well as the condition of the ...

Abstract	Seagrasses are globally recognized as bioindicators of marine eutrophication and contamination. Seagrasses also harbor a distinct root microbial community that largely reflects the conditions of the surrounding environment as well as the condition of the seagrass. Hence monitoring changes in the root microbial community could act as an additional biological indicator that reflects both the seagrass health condition, as well as potential deterioration in coastal waters. We used 16S rRNA gene sequencing combined with analysis of seagrass nutrients (C, N, δ15N, δ13C) and tissue metal concentrations to investigate potential links between seagrass (Halophila ovalis) root bacteria and seagrass nutrient and metal concentrations within an anthropogenically influenced estuary. We found seagrass tissue nitrogen (%) and δ15N values were 2–5 times higher than global averages for this species. Seagrass root associated bacteria formed distinct communities that clustered by site and were correlated to both seagrass nutrient and metal concentration, with some putative sulfide oxidizing bacteria (Sulfurimonas and Sulfurovum) correlated with greater nutrient concentrations, and putative iron cycling bacteria (Lewinella and Woeseia) correlated with greater Fe and As concentrations. Our findings shed further light on the relationship between seagrass and their microbes, as well as provide additional assessment of the use of both seagrass and their microbes as indicators of estuarine and seagrass condition.
Keywords	microbiome ; stable isotopes ; nitrogen ; carbon ; 16S rRNA ; arsenic ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
Subject code	333
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: The Risk of Multiple Anthropogenic and Climate Change Threats Must Be Considered for Continental Scale Conservation and Management of Seagrass Habitat

Kathryn McMahon / Kieryn Kilminster / Robert Canto / Chris Roelfsema / Mitchell Lyons / Gary A. Kendrick / Michelle Waycott / James Udy

Frontiers in Marine Science, Vol

2022 Volume 9

Abstract: Globally marine-terrestrial interfaces are highly impacted due to a range of human pressures. Seagrass habitats exist in the shallow marine waters of this interface, have significant values and are impacted by a range of pressures. Cumulative risk ... ...

Abstract	Globally marine-terrestrial interfaces are highly impacted due to a range of human pressures. Seagrass habitats exist in the shallow marine waters of this interface, have significant values and are impacted by a range of pressures. Cumulative risk analysis is widely used to identify risk from multiple threats and assist in prioritizing management actions. This study conducted a cumulative risk analysis of seagrass habitat associated with the Australian continent to support management actions. We developed a spatially explicit risk model based on a database of threats to coastal aquatic habitat in Australia, spanning 35,000 km of coastline. Risk hotspots were identified using the model and reducing the risk of nutrient and sediment pollution for seagrass habitat was assessed. Incorporating future threats greatly altered the spatial-distribution of risk. High risk from multiple current threats was identified throughout all bioregions, but high risk from climate change alone manifested in only two. Improving management of nutrient and sediment loads, a common approach to conserve seagrass habitat did reduce risk, but only in temperate regions, highlighting the danger of focusing management on a single strategy. Monitoring, management and conservation actions from a national and regional perspective can be guided by these outputs.
Keywords	coastal habitat ; seagrass ; risk assessment ; climate change ; management ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
Subject code	333
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Seasonal links between metabolites and traditional seagrass metrics in the seagrass Halophila ovalis in an estuarine system

E. Maria U. Jung / Jeffrey J. Cosgrove / Belinda C. Martin / Maike Bollen / Gary A. Kendrick / Matthew W. Fraser

Ecological Indicators, Vol 143, Iss , Pp 109315- (2022)

2022

Abstract: Monitoring of seagrasses has mainly relied on traditional seagrass metrics (e.g., biomass), which deliver reliable information about mortality but are unable to inform about impacts on seagrass health at the very early stages of stress exposure. ... ...

Abstract	Monitoring of seagrasses has mainly relied on traditional seagrass metrics (e.g., biomass), which deliver reliable information about mortality but are unable to inform about impacts on seagrass health at the very early stages of stress exposure. Metabolomics is a novel molecular technique which can be used for early stress-detection in plants and also for unravelling the underlying mechanisms of stress response. In the Swan-Canning Estuary, south-west Australia, the seagrass Halophila ovalis is impacted by seasonal changes in sediment-and nutrient-stress. To date, it is unknown how H. ovalis responds to these seasonal stressors on a molecular level. Here, we used a combined approach of traditional seagrass metrics and metabolomics to create a holistic picture of seasonal influences on seagrass condition. Leaf samples of H. ovalis were collected from six different locations in the Swan-Canning Estuary in both summer and spring. We detected strong differences in metabolite profiles and relative metabolite abundance between seasons, with growth- and/or development-related metabolites being up-regulated in spring and stress-related (secondary) metabolites being up-regulated in summer. Metabolites were mostly related to leaf δ13C signatures, a metric that has been previously associated with variation in light and pH in the Swan-Canning. We demonstrate that a holistic approach which includes metabolomics into ecological monitoring can help to improve our understanding of the mechanisms underlying molecular (stress) responses in seagrasses which is crucial knowledge for management and conservation measures locally and globally.
Keywords	Metabolomics ; Seagrass metrics ; Halophila ovalis ; Estuary ; Seasons ; Ecological monitoring ; Ecology ; QH540-549.5
Language	English
Publishing date	2022-10-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Belowground stressors and long-term seagrass declines in a historically degraded seagrass ecosystem after improved water quality

Matthew W. Fraser / Gary A. Kendrick

Scientific Reports, Vol 7, Iss 1, Pp 1-

2017 Volume 11

Abstract: Abstract Continued seagrass declines in ecosystems with improved water quality may be driven by sediment stressors. One of the most cited examples of a seagrass ecosystem with declines is Cockburn Sound, Western Australia, where 75% of seagrasses (2169 ... ...

Abstract	Abstract Continued seagrass declines in ecosystems with improved water quality may be driven by sediment stressors. One of the most cited examples of a seagrass ecosystem with declines is Cockburn Sound, Western Australia, where 75% of seagrasses (2169 ha) were lost in the 1960s–1980s due to poor water quality. Water quality has subsequently improved in Cockburn Sound, yet shoot density declines continue in some areas. Here, we investigated if sediment stressors (sulfide intrusion and heavy metals) contributed to declining Posidonia sinuosa shoot densities in Cockburn Sound. Seagrass δ34S were depleted at sites with a history of seagrass declines, indicating seagrasses at these sites were under sulfide stress. Heavy metals (Fe, Zn, Mn, Cr, Cu and Cd) in sediments and seagrasses did not show clear patterns with shoot density or biomass, and largely decreased from similar measurements in the late 1970s. However, seagrass cadmium concentrations were negatively correlated to seagrass biomass and shoot density. High cadmium concentrations interfere with sulfur metabolism in terrestrial plants, but impacts on seagrasses remain to be explored. Given that sulfide intrusion can prevent recolonization and drive seagrass declines, management plans in degraded seagrass ecosystems should include management of sediment stressors and water quality to provide comprehensive management.
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2017-10-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Salinity stress drives herbivory rates and selective grazing in subtidal seagrass communities.

Sahira Y Bell / Matthew W Fraser / John Statton / Gary A Kendrick

PLoS ONE, Vol 14, Iss 3, p e

2019 Volume 0214308

Abstract: The role of environmental-stress gradients in driving trophic processes like grazing, has potential to shape ecosystem responses to environmental change. In subtidal seagrass systems, however, the variation in top-down processes along stress gradients ... ...

Abstract	The role of environmental-stress gradients in driving trophic processes like grazing, has potential to shape ecosystem responses to environmental change. In subtidal seagrass systems, however, the variation in top-down processes along stress gradients are poorly understood. We deployed herbivory assays using the five most common seagrass species of Shark Bay, to determine whether herbivory pressure changed across a salinity-stress gradient from oceanic (38 PSU) to hyper-saline (51 PSU) conditions. Seagrass tissue removed from herbivory assays by fishes decreased as environmental stress increased, and herbivores consumed greater amounts of tropical seagrass species compared to the temperate species that dominate seagrass cover in Shark Bay. This heightened consumption was correlated with enriched seagrass nutrient concentrations. Our work suggests there's a fundamental relationship between trophic interactions and environmental conditions within complex marine settings. Abiotic stressors like salinity directly impact seagrass communities physiologically; however we show that salinity stressors also shift biotic interactions, indirectly influencing grazing rates and thus having a greater effect on seagrasses than physiological impacts alone. In Shark Bay where restoration efforts are being employed to address large scale loss of seagrasses, the relationship between herbivory pressure and salinity-stress could therefore prove crucial to restoration success.
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2019-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Identifying critical recruitment bottlenecks limiting seedling establishment in a degraded seagrass ecosystem

John Statton / Leonardo R. Montoya / Robert J. Orth / Kingsley W. Dixon / Gary A. Kendrick

Scientific Reports, Vol 7, Iss 1, Pp 1-

2017 Volume 12

Abstract: Abstract Identifying early life-stage transitions limiting seagrass recruitment could improve our ability to target demographic processes most responsive to management. Here we determine the magnitude of life-stage transitions along gradients in physical ...

Abstract	Abstract Identifying early life-stage transitions limiting seagrass recruitment could improve our ability to target demographic processes most responsive to management. Here we determine the magnitude of life-stage transitions along gradients in physical disturbance limiting seedling establishment for the marine angiosperm, Posidonia australis. Transition matrix models and sensitivity analyses were used to identify which transitions were critical for successful seedling establishment during the first year of seed recruitment and projection models were used to predict the most appropriate environments and seeding densities. Total survival probability of seedlings was low (0.001), however, transition probabilities between life-stages differed across the environmental gradients; seedling recruitment was affected by grazing and bioturbation prevailing during the first life-stage transition (1 month), and 4–6 months later during the third life-stage transition when establishing seedlings are physically removed by winter storms. Models projecting population growth from different starting seed densities showed that seeds could replace other more labour intensive and costly methods, such as transplanting adult shoots, if disturbances are moderated sufficiently and if large numbers of seed can be collected in sufficient quantity and delivered to restoration sites efficiently. These outcomes suggest that by improving management of early demographic processes, we could increase recruitment in restoration programs.
Keywords	Medicine ; R ; Science ; Q
Subject code	333
Language	English
Publishing date	2017-11-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: A novel adaptation facilitates seed establishment under marine turbulent flows

Gary A. Kendrick / Andrew W. Pomeroy / Robert J. Orth / Marion L. Cambridge / Jeremy Shaw / Lukasz Kotula / Ryan J. Lowe

Scientific Reports, Vol 9, Iss 1, Pp 1-

2019 Volume 8

Abstract: Abstract Seeds of Australian species of the seagrass genus Posidonia are covered by a membranous wing that we hypothesize plays a fundamental role in seed establishment in sandy, wave swept marine environments. Dimensions of the seed and membrane were ... ...

Abstract	Abstract Seeds of Australian species of the seagrass genus Posidonia are covered by a membranous wing that we hypothesize plays a fundamental role in seed establishment in sandy, wave swept marine environments. Dimensions of the seed and membrane were quantified under electron microscopy and micro-CT scans, and used to model rotational, drag and lift forces. Seeds maintain contact with the seabed in the presence of strong turbulence: the larger the wing, the more stable the seed. Wing surface area increases from P. sinuosa < P. australis < P.coriacea correlating with their ability to establish in increasingly energetic environments. This unique seed trait in a marine angiosperm corresponds to adaptive pressures imposed on seagrass species along 7,500 km of Australia’s coastline, from open, high energy coasts to calmer environments in bays and estuaries.
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2019-12-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED