scholarly journals Variation in Phenolic Chemistry in Zostera marina Seagrass along Environmental Gradients

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 334
Author(s):  
Cecilie Sævdal Dybsland ◽  
Trine Bekkby ◽  
Kjersti Hasle Enerstvedt ◽  
Olav M. Kvalheim ◽  
Eli Rinde ◽  
...  
Keyword(s):  
Zostera Marina ◽  
Rosmarinic Acid ◽  
Seagrass Meadow ◽  
Wave Exposure ◽  
Full Potential ◽  
Monitoring Tool ◽  
Higher Plant ◽  
Ecosystem Monitoring ◽  
Seagrass Ecosystem ◽  
Acid Ratio

Chemical ecology has been suggested as a less time-consuming and more cost-efficient monitoring tool of seagrass ecosystems than traditional methods. Phenolic chemistry in Zostera marina samples was analyzed against latitude, sea depth, sample position within a seagrass meadow (periphery or center) and wave exposure. Multivariate data analysis showed that rosmarinic acid correlated moderately positively with depth, while the flavonoids had an overall strong negative correlation with increasing depth—possibly reflecting lack of stress-induced conditions with increasing depth, rather than a different response to light conditions. At a molecular level, the flavonoids were separated into two groups; one group is well described by the variables of depth and wave exposure, and the other group that was not well described by these variables—the latter may reflect biosynthetic dependencies or other unrevealed factors. A higher flavonoid/rosmarinic acid ratio was seen in the periphery of a seagrass meadow, while the contrary ratio was seen in the center. This may reflect higher plant stress in the periphery of a meadow, and the flavonoid/rosmarinic acid ratio may provide a possible molecular index of seagrass ecosystem health. Further studies are needed before the full potential of using variation in phenolic chemistry as a seagrass ecosystem monitoring tool is established.

Ecosystem monitoring of a seagrass meadow using wideband acoustic measurements

2021 ◽  
Vol 150 (4) ◽  
pp. A351-A351
Author(s):  
Megan S. Ballard ◽  
Kevin M. Lee ◽  
Andrew R. McNeese ◽  
Gabriel R. Venegas ◽  
Abdullah F. Rahman ◽  
...  
Keyword(s):  
Seagrass Meadow ◽  
Acoustic Measurements ◽  
Ecosystem Monitoring

Application of geoacoustic inference for ecosystem monitoring of a seagrass meadow

2018 ◽  
Vol 144 (3) ◽  
pp. 1913-1913
Author(s):  
Megan S. Ballard ◽  
Jason D. Sagers ◽  
Gabriel R. Venegas ◽  
Kevin M. Lee ◽  
Andrew R. McNeese ◽  
...  
Keyword(s):  
Seagrass Meadow ◽  
Ecosystem Monitoring

scholarly journals Application of acoustical remote sensing techniques for ecosystem monitoring of a seagrass meadow

2020 ◽  
Vol 147 (3) ◽  
pp. 2002-2019 ◽  
Author(s):  
Megan S. Ballard ◽  
Kevin M. Lee ◽  
Jason D. Sagers ◽  
Gabriel R. Venegas ◽  
Andrew R. McNeese ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Seagrass Meadow ◽  
Ecosystem Monitoring ◽  
Remote Sensing Techniques

Spatial distribution of the Black Sea copepod, Calanus euxinus, estimated using multi-frequency acoustic backscatter

2016 ◽  
Vol 74 (3) ◽  
pp. 832-846 ◽  
Author(s):  
Serdar Sakınan ◽  
Ali Cemal Gücü
Keyword(s):  
Black Sea ◽  
Developmental Stages ◽  
Trophic Levels ◽  
Acoustic Backscatter ◽  
The Black Sea ◽  
Monitoring Tool ◽  
Specific Density ◽  
Ecosystem Monitoring ◽  
Acoustic Surveys ◽  
Deep Distribution

The copepod Calanus euxinus is a key prey species for fish in the Black Sea. To estimate the distribution and biomass of the late developmental stages of this species in July 2013, we analysed multi-frequency (38, 120, and 200 kHz) echo-sounder data from a fisheries survey of the Black Sea. The dependence of acoustic backscatter on frequency, i.e. the frequency response, was estimated for daytime scattering layers, which were confirmed by net catches to be dense, post-copepodite-stage (C4) aggregations of C. euxinus with prosome lengths greater than 2 mm. The high-resolution acoustic observations revealed that the nighttime, shallow distribution was bounded by the lower portion of the thermocline and that the daytime, deep distribution was bounded by oxygen. The dense and isolated aggregations were observed in seawater with a specific density, σT, of between 15.2 and 15.9 kg m−3. These results show that fisheries acoustic surveys, typically targeting only commercially exploited fish species, may also provide information on the lower trophic levels and thereby serve as an ecosystem-monitoring tool.

scholarly journals Influence of hydrodynamic setting on Posidonia oceanica meadow landscape and architecture

2015 ◽  
Author(s):  
Matthew Pace ◽  
Joseph A Borg ◽  
Charles Galdies
Keyword(s):  
Seagrass Meadow ◽  
Posidonia Oceanica ◽  
High Energy ◽  
Wave Exposure ◽  
Exposure Model ◽  
Eastern Coast ◽  
Seagrass Habitat ◽  
Physical Factors ◽  
The North ◽  
Architectural Features

Seagrass meadow characteristics, including distribution, shape, size, and within-meadow architectural features may be influenced by various physical factors, including hydrodynamic forces. However, such influence has hardly been assessed for meadows of the ecologically important and endemic Mediterranean seagrass Posidonia oceanica. Estimates of wind- generated wave energy and the energy attenuated by depth were computed by a hydrodynamic model, WEMo (Wave Exposure Model), for five sites on the north-eastern coast of the Maltese Islands which each supported patchy, reticulate and continuous bed types of Posidonia oceanica. The distribution of P. oceanica meadows at these sites were mapped to a depth of circa 15m using a combination of aerial photography and SCUBA diving surveys. Data on meadow architectural attributes were collected for each of the three P. oceanica bed types at each of the five study sites. Metrics for P. oceanica landscape features were calculated via FRAGSTATS v4 for replicate 2500m2 subsamples that were extracted from the seagrass habitat maps. The results indicate that landscape and architectural features of relatively deep P. oceanica meadows are significantly influenced by the hydrodynamic setting. P. oceanica meadows tend to be patchier with lower overall cover, more complex patch shapes and reduced architectural complexity along a wave exposure gradient from low to high energy. The findings from the present study highlight the importance of understanding the influence of hydrodynamic factors on the natural dynamism of seagrass meadow landscape and architecture for the conservation and management of P. oceanica habitat.

scholarly journals Size spectra analysis of a decade of Laurentian Great Lakes data

2021 ◽  
Author(s):  
Thomas M Evans ◽  
Zachary S Feiner ◽  
Lars G Rudstam ◽  
Doran M. Mason ◽  
James M Watkins ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Great Lakes ◽  
Laurentian Great Lakes ◽  
Benthic Organisms ◽  
Monitoring Tool ◽  
Ecosystem Monitoring ◽  
Size Spectra ◽  
Seasonal Differences ◽  
Spectra Analysis ◽  
Time Period

Size spectra analysis (SSA) is used to detect changes in food webs by simplifying complex community structures through abundance-versus-biomass considerations. We applied SSA to 10 years (2006-2015) of data on Great Lakes organisms ranging in size from picoplankton to macrozooplankton. Summer pelagic size spectra slopes were near the theoretical value of -1.0, but spring slopes were steeper, reflecting seasonal differences in abundance of small and large individuals. Pelagic size spectra slopes were relatively stable over the time period we examined. Height (the predicted number of organisms at the spectra midpoint) varied among lakes and was slightly higher in summer than spring in more productive basins. Including benthic data led to shallower slopes when combined with pelagic data, suggesting benthic organisms may increase food web efficiency; height was less affected by benthic data. Benthic data are not routinely included in SSA, but our results suggest they affect slopes and therefore SSA-based predictions of fish abundance. The ability of SSA to track changes in trophic energy transfer makes it a valuable ecosystem monitoring tool.

scholarly journals All small things considered: the diversity of fungi, bacteria and oomycota isolated from the seagrass, Zostera marina

2020 ◽  
Author(s):  
Cassandra L. Ettinger ◽  
Jonathan A. Eisen
Keyword(s):  
Zostera Marina ◽  
Leaf Tissue ◽  
Culture Collection ◽  
Bacterial Isolates ◽  
Opportunistic Pathogens ◽  
Microbial Eukaryotes ◽  
Fungal Isolates ◽  
Phylogenetic Methods ◽  
Seagrass Ecosystem ◽  
Small Things

AbstractFungi in the marine environment are often neglected as a research topic, despite that fungi having critical roles on land as decomposers, pathogens or beneficial endophytes. Here we used culture-dependent methods to survey the fungi associated with the seagrass, Zostera marina, also obtaining bacteria and oomycete isolates in the process. A total of 108 fungi, 41 bacteria and 2 oomycetes were isolated. These isolates were then taxonomically identified using a combination of molecular and phylogenetic methods. The majority of the fungal isolates were classified as belonging to the classes Eurotiomycetes, Dothideomycetes, and Sordariomycetes. Most fungal isolates were habitat generalists like Penicillium sp. and Cladosporium sp., but we also cultured a diverse set of rare taxa including possible habitat specialists like Colletotrichum sp. which may preferentially associate with Z. marina leaf tissue. Although the bulk of bacterial isolates were identified as being from known ubiquitous marine lineages, we also obtained several Actinomycetes isolates which might produce interesting secondary metabolites and a Phyllobacterium sp. which may be involved in nitrogen cycling in the seagrass ecosystem. We identified two oomycetes, another understudied group of marine microbial eukaryotes, as Halophytophthora sp. which may be opportunistic pathogens of Z. marina. Overall, this study generates a culture collection of fungi, bacteria and oomycetes which expands knowledge of the diversity of Z. marina associated microbes and highlights a need for more investigation into the functional and evolutionary roles of microbial eukaryotes associated with seagrasses.

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