scholarly journals EELGRASS MAPPING WITH SENTINEL-2 AND UAV DATA IN PRINCE EDWARD ISLAND (CANADA)

2021 ◽  
Vol V-3-2021 ◽  
pp. 125-132
Author(s):  
E. Gallant ◽  
A. LaRocque ◽  
B. Leblon ◽  
A. Douglas
Keyword(s):  
Random Forests ◽  
Zostera Marina ◽  
Prince Edward Island ◽  
Marine Species ◽  
Atlantic Canada ◽  
Eelgrass Beds ◽  
Future Work ◽  
Classified Image ◽  
Sentinel 2 ◽  
Marine Angiosperm

Abstract. Eelgrass (Zostera marina L.) is a marine angiosperm that grows throughout coastal regions in Atlantic Canada. Eelgrass beds provide a variety of important ecosystem services, and while it is considered an important marine species, little research has been done to understand its distribution and location within Atlantic Canada. The purpose of this study was to assess the capability of Sentinel-2 and UAV imagery to map the presence of eelgrass beds within the Souris River in Prince Edward Island. Both imageries were classified using the non-parametric Random Forests (RF) supervised classifier and the resulting classification was validated using sonar data. The Sentinel-2 classified image had a lower validation accuracy at 77.7%, while the UAV classified image had a validation accuracy of 90.9%. The limitations of the study and recommendations for future work are also presented.

scholarly journals EELGRASS MAPPING IN ATLANTIC CANADA USING WORLDVIEW-2 IMAGERY

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 685-692
Author(s):  
D. Forsey ◽  
B. Leblon ◽  
A. LaRocque ◽  
M. Skinner ◽  
A. Douglas
Keyword(s):  
Ecosystem Services ◽  
New Brunswick ◽  
Random Forests ◽  
Zostera Marina ◽  
Atlantic Canada ◽  
Maximum Likelihood Classifier ◽  
Supervised Classifiers ◽  
Estuarine Lagoon ◽  
Better Than ◽  
Marine Angiosperm

Abstract. Eelgrass (Zostera marina L.) is a marine angiosperm plant that grows throughout coastal areas in Atlantic Canada. Eelgrass meadows provide numerous ecosystem services, and while they have been acknowledged as important habitats, their location, extent, and health in Atlantic Canada are poorly understood. This study examined the effectiveness of WorldView-2 optical satellite imagery to map eelgrass presence in Tabusintac Bay, New Brunswick (Canada), an estuarine lagoon with extensive eelgrass coverage. The imagery was classified using two supervised classifiers: the parametric Maximum Likelihood Classifier (MLC) and the non-parametric Random Forests (RF) classifier. While Random Forests was expected to produce higher classification accuracies, it was shown not to be much better than MLC. The overall validation accuracy was 97.6% with RF and 99.8% with MLC.

scholarly journals Disruption of essential habitat by a coastal invader: new evidence of the effects of green crabs on eelgrass beds

2011 ◽  
Vol 68 (9) ◽  
pp. 1852-1856 ◽  
Author(s):  
Andrey Malyshev ◽  
Pedro A. Quijón
Keyword(s):  
Invasive Species ◽  
Zostera Marina ◽  
Laboratory Experiments ◽  
Carcinus Maenas ◽  
Green Crab ◽  
Atlantic Canada ◽  
Marine Science ◽  
Eelgrass Beds ◽  
New Evidence

Abstract Malyshev, A., and Quijón, P. A. 2011. Disruption of essential habitat by a coastal invader: new evidence of the effects of green crabs on eelgrass beds. – ICES Journal of Marine Science, 68: 1852–1856. Eelgrass (Zostera marina) beds have been declining in Atlantic Canada and elsewhere, partly as a result of sediment disruption and direct feeding/cutting of basal meristems by the green crab (Carcinus maenas). Green crabs are detrimental to eelgrass beds, and field and laboratory experiments have confirmed that the deleterious role of this invasive species is mediated by at least two mechanisms, depending on the size/age of the crabs: uprooting by adults and grazing by juveniles. Eelgrass uprooting and grazing by green crabs are likely to contribute to further declines or a lack of recovery of eelgrass beds.

scholarly journals More than a stick in the mud: Eelgrass leaf and root bacterial communities are distinct from those on physical mimics

2021 ◽  
Author(s):  
Melissa R Kardish ◽  
John J Stachowicz
Keyword(s):  
Microbial Communities ◽  
Zostera Marina ◽  
Bacterial Communities ◽  
Functional Role ◽  
Biotic Interactions ◽  
Physical Structure ◽  
Intact Plants ◽  
Future Work ◽  
Marine Angiosperm

We examine the role of physical structure vs. biotic interactions in structuring host-associated microbial communities on a marine angiosperm, Zostera marina, eelgrass. Across several months and sites, we compared microbiomes on physical mimics of eelgrass roots and leaves to those on intact plants. We find large, consistent differences in the microbiome of mimics and plants, especially on roots, but also on leaves. Key taxa that are more abundant on leaves have been associated with microalgal and macroalgal disease and merit further investigation to determine their role in mediating plant-microalgal-pathogen interactions. Root associated taxa were associated with sulfur and nitrogen cycling, potentially ameliorating environmental stresses for the plant. Our work identifies targets for future work on the functional role of the seagrass microbiome in promoting the success of these angiosperms in the sea.

scholarly journals Variation of carbon contents in eelgrass ( Zostera marina ) sediments implied from depth profiles

2019 ◽  
Vol 15 (6) ◽  
pp. 20180831 ◽  
Author(s):  
Theodor Kindeberg ◽  
Emilia Röhr ◽  
Per-Olav Moksnes ◽  
Christoffer Boström ◽  
Marianne Holmer
Keyword(s):  
Organic Carbon ◽  
Zostera Marina ◽  
Large Scale ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Depth Profiles ◽  
Seagrass Meadows ◽  
Spatio Temporal ◽  
Organic Carbon Storage ◽  
Eelgrass Beds

Seagrass meadows are able to store significant amounts of organic carbon in their underlying sediment, but global estimates are uncertain partly owing to spatio-temporal heterogeneity between and within areas and species. In order to provide robust estimates, there is a need to better understand the fate of, and mechanisms behind, organic carbon storage. In this observational study, we analyse a suite of biotic and abiotic parameters in sediment cores from 47 different eelgrass ( Zostera marina ) beds spanning the distributional range of the Northern Hemisphere. Depth profiles of particulate organic carbon (POC) revealed three patterns of vertical distribution where POC either increased, decreased or showed no pattern with sediment depth. These categories exhibited distinct profiles of δ 13 C and C:N ratios, where high POC profiles had a proportionally larger storage of eelgrass-derived material whereas low POC profiles were dominated by phytoplanktonic and macroalgal material. However, high POC did not always translate into high carbon density. Nevertheless, this large-scale dataset provides evidence that the variability in organic matter source in response to natural and anthropogenic environmental changes affects the potential role of eelgrass beds as POC sinks, particularly where eelgrass decline is observed.

scholarly journals Chlororespiration Serves as Photoprotection for the Photo-Inactivated Oxygen-Evolving Complex in Zostera marina, a Marine Angiosperm

2020 ◽  
Vol 61 (8) ◽  
pp. 1517-1529
Author(s):  
Ying Tan ◽  
Quan Sheng Zhang ◽  
Wei Zhao ◽  
Zhe Liu ◽  
Ming Yu Ma ◽  
...  
Keyword(s):  
Zostera Marina ◽  
Thylakoid Membrane ◽  
Physiological Role ◽  
Reducing Power ◽  
Pentose Phosphate ◽  
Oxygen Evolving Complex ◽  
Redox Equilibrium ◽  
Strong Connectivity ◽  
Oxygen Evolving ◽  
Marine Angiosperm

Abstract As an alternative electron sink, chlororespiration, comprising the NAD(P)H dehydrogenase complex and plastid terminal plastoquinone oxidase, may play a significant role in sustaining the redox equilibrium between stroma and thylakoid membrane. This study identified a distinct role for chlororespiration in the marine angiosperm Zostera marina, whose oxygen-evolving complex (OEC) is prone to photo-inactivation as a result of its inherent susceptibility to excess irradiation. The strong connectivity between OEC peripheral proteins and key chlororespiratory enzymes, as demonstrated in the interaction network of differentially expressed genes, suggested that the recovery of photo-inactivated OEC was connected with chlororespiration. Chlorophyll fluorescence, transcriptome and Western blot data verified a new physiological role for chlororespiration to function as photoprotection and generate a proton gradient across the thylakoid membrane for the recovery of photo-inactivated OEC. Chlororespiration was only activated in darkness following excess irradiation exposure, which might be related to electron deficiency in the electron transport chain because of the continuous impairment of the OEC. The activation of chlororespiration in Z. marina was prone to proactivity, which was also supported by the further activation of the oxidative pentose-phosphate pathway synthesizing NADPH to meet the demand of chlororespiration during darkness. This phenomenon is distinct from the common assumption that chlororespiration is prone to consuming redundant reducing power during the short transition phase from light to dark.

scholarly journals Adventive and native Byrrhidae (Coleoptera) newly recorded from Prince Edward Island, Canada

Zootaxa ◽  
2006 ◽  
Vol 1168 (1) ◽  
pp. 21 ◽  
Author(s):  
CHRISTOPHER G. MAJKA ◽  
CHRISTINE NORONHA ◽  
MARY SMITH
Keyword(s):  
Exotic Species ◽  
Prince Edward Island ◽  
Atlantic Canada ◽  
Adventive Species ◽  
History Of ◽  
First Time

The Palearctic byrrhids Chaetophora spinosa (Rossi) and Simplocaria semistriata (F.) are reported for the first time from Prince Edward Island (PEI), the former species for the first time from Atlantic Canada from specimens collected in 2003–05. Their presence is discussed both in light of the history of introductions of exotic species in Atlantic Canada in general, and on PEI in particular, and also in the context of the effect of adventive species on native organisms and ecosystems. These discoveries underscore the need for continual monitoring of invertebrate populations to detect ongoing introductions of adventive species. The native byrrhid Cytilus alternatus (Say) is also reported for the first time from PEI.

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