scholarly journals A Portable Cruising Speed Net: Expanding Global Collection of Sea Surface Plankton Data

2020 ◽  
Vol 7 ◽  
Author(s):  
Ulla von Ammon ◽  
Andrew Jeffs ◽  
Anastasija Zaiko ◽  
Aimee van der Reis ◽  
Deb Goodwin ◽  
...  
Keyword(s):  
Global Climate ◽  
Atmospheric Oxygen ◽  
Field Testing ◽  
Biological Data ◽  
Latitudinal Gradients ◽  
Distribution Data ◽  
East Indian ◽  
Marine Food Chain ◽  
Dna Metabarcoding ◽  
East Indian Ocean

Plankton are central to planetary ecology, generating 50% of Earth’s atmospheric oxygen and forming the largest system of interconnected life at the base of the marine food chain. Yet, current oceanographic models aimed at predicting global climate change lack high-resolution biological data, emphasizing the need for innovative approaches to collect plankton biodiversity and distribution data over larger spatial, temporal, and taxonomic scales. The significant number of boats, ranging from small sailing yachts to large commercial vessels, that ply the world’s oceans every day could help scientists collect thousands of valuable plankton samples. Traditional Plankton Nets (TPN) are not suited to the speed of a recreational craft cruising in the high seas (i.e., at speeds >2 knots). We developed and validated the efficiency of a lightweight, easily deployable Cruising Speed Net (CSN) that enables the collection of ocean surface micro- and mesoplankton at speeds up to 5 knots. Field testing was conducted during two distinct research cruises along coastal and oceanic latitudinal gradients (SSV Robert C. Seamans in New Zealand and RV Investigator in the south-east Indian Ocean). DNA metabarcoding performed on the collected plankton samples showed the TPN and CSN yielded identical sequence-based diversity at low speed, with the CSN also effective at higher speed for characterizing latitudinal distribution of plankton communities. The CSN represents a valuable new tool for expanding the global collection of plankton data.

scholarly journals A Marine Reservoir Correction for the Houtman-Abrolhos Archipelago, East Indian Ocean, Western Australia

Radiocarbon ◽  
2013 ◽  
Vol 55 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Peter Squire ◽  
Renaud Joannes-Boyau ◽  
Anja M Scheffers ◽  
Luke D Nothdurft ◽  
Quan Hua ◽  
...  
Keyword(s):  
Southern Oscillation ◽  
Global Climate ◽  
Current Source ◽  
Lower Latitude ◽  
East Indian ◽  
Leeuwin Current ◽  
Coral Communities ◽  
Nw Australia ◽  
East Indian Ocean ◽  
Reservoir Age

High-precision analysis using accelerator mass spectrometry (AMS) was performed upon known-age Holocene and modern, pre-bomb coral samples to generate a marine reservoir age correction value (ΔR) for the Houtman-Abrolhos Archipelago (28.7°S, 113.8°E) off the Western Australian coast. The mean ΔR value calculated for the Abrolhos Islands, 54 ± 30 yr (1 σ) agrees well with regional ΔR values for Leeuwin Current source waters (N-NW Australia-Java) of 60 ± 38 yr. The Abrolhos Islands show little variation with ΔR values of the northwestern and north Australian coast, underlining the dominance of the more equilibrated western Pacific-derived waters of the Leeuwin Current over local upwelling. The Abrolhos Islands ΔR values have remained stable over the last 2896 cal yr BP, being also attributed to the Leeuwin Current and the El Niño Southern Oscillation (ENSO) signal during this period. Expected future trends will be a strengthening of the teleconnection of the Abrolhos Islands to the climatic patterns of the equatorial Pacific via enhanced ENSO and global warming activity strengthening the Leeuwin Current. The possible effect upon the trend of future ΔR values may be to maintain similar values and an increase in stability. However, warming trends of global climate change may cause increasing dissimilarity of ΔR values due to the effects of increasing heat stress upon lower-latitude coral communities.

scholarly journals A Marine Reservoir Correction for the Houtman-Abrolhos Archipelago, East Indian Ocean, Western Australia

Radiocarbon ◽  
2013 ◽  
Vol 55 (01) ◽  
pp. 103-114 ◽  
Author(s):  
Peter Squire ◽  
Renaud Joannes-Boyau ◽  
Anja M Scheffers ◽  
Luke D Nothdurft ◽  
Quan Hua ◽  
...  
Keyword(s):  
Southern Oscillation ◽  
Global Climate ◽  
Current Source ◽  
Lower Latitude ◽  
East Indian ◽  
Leeuwin Current ◽  
Coral Communities ◽  
Nw Australia ◽  
East Indian Ocean ◽  
Reservoir Age

High-precision analysis using accelerator mass spectrometry (AMS) was performed upon known-age Holocene and modern, pre-bomb coral samples to generate a marine reservoir age correction value (ΔR) for the Houtman-Abrolhos Archipelago (28.7°S, 113.8°E) off the Western Australian coast. The mean ΔR value calculated for the Abrolhos Islands, 54 ± 30 yr (1 σ) agrees well with regional ΔR values for Leeuwin Current source waters (N-NW Australia-Java) of 60 ± 38 yr. The Abrolhos Islands show little variation with ΔR values of the northwestern and north Australian coast, underlining the dominance of the more equilibrated western Pacific-derived waters of the Leeuwin Current over local upwelling. The Abrolhos Islands ΔR values have remained stable over the last 2896 cal yr BP, being also attributed to the Leeuwin Current and the El Niño Southern Oscillation (ENSO) signal during this period. Expected future trends will be a strengthening of the teleconnection of the Abrolhos Islands to the climatic patterns of the equatorial Pacific via enhanced ENSO and global warming activity strengthening the Leeuwin Current. The possible effect upon the trend of future ΔR values may be to maintain similar values and an increase in stability. However, warming trends of global climate change may cause increasing dissimilarity of ΔR values due to the effects of increasing heat stress upon lower-latitude coral communities.

scholarly journals A trait-based approach to assess climate change sensitivity of freshwater invertebrates across Swedish ecoregions

2014 ◽  
Vol 60 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Leonard Sandin ◽  
Astrid Schmidt-Kloiber ◽  
Jens-Christian Svenning ◽  
Erik Jeppesen ◽  
Nikolai Friberg
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Species Traits ◽  
Freshwater Ecosystems ◽  
Biological Data ◽  
Conservation Strategies ◽  
Measured Temperature ◽  
Buffer Strips

Abstract Freshwater habitats and organisms are among the most threatened on Earth, and freshwater ecosystems have been subject to large biodiversity losses. We developed a Climate Change Sensitivity (CCS) indicator based on trait information for a selection of stream- and lake-dwelling Ephemeroptera, Plecoptera and Trichoptera taxa. We calculated the CCS scores based on ten species traits identified as sensitive to global climate change. We then assessed climate change sensitivity between the six main ecoregions of Sweden as well as the three Swedish regions based on Illies. This was done using biological data from 1, 382 stream and lake sites where we compared large-scale (ecoregional) patterns in climate change sensitivity with potential future exposure of these ecosystems to increased temperatures using ensemble-modelled future changes in air temperature. Current (1961~1990) measured temperature and ensemble-modelled future (2100) temperature showed an increase from the northernmost towards the southern ecoregions, whereas the predicted temperature change increased from south to north. The CCS indicator scores were highest in the two northernmost boreal ecoregions where we also can expect the largest global climate change-induced increase in temperature, indicating an unfortunate congruence of exposure and sensitivity to climate change. These results are of vital importance when planning and implementing management and conservation strategies in freshwater ecosystems, e.g., to mitigate increased temperatures using riparian buffer strips. We conclude that traits information on taxa specialization, e.g., in terms of feeding specialism or taxa having a preference for high altitudes as well as sensitivity to changes in temperature are important when assessing the risk from future global climate change to freshwater ecosystems.

scholarly journals Mineral protection regulates the long-term global preservation of natural organic carbon

2021 ◽  
Author(s):  
Jordon Hemingway ◽  
Daniel Rothman ◽  
Katherine Grant ◽  
Sarah Rosengard ◽  
Timothy Eglinton ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Redox State ◽  
Global Climate ◽  
Atmospheric Oxygen ◽  
Atmospheric Composition ◽  
Earth Surface ◽  
Mountain Ranges ◽  
Surface Redox ◽  
Carbon Erosion

<p>The vast majority of organic carbon (OC) produced by life is respired back to carbon dioxide (CO<sub>2</sub>), but roughly 0.1% escapes and is preserved over geologic timescales. By sequestering reduced carbon from Earth’s surface, this “slow OC leak” contributes to CO<sub>2</sub> removal and promotes the accumulation of atmospheric oxygen and oxidized minerals. Countering this, OC contained within sedimentary rocks is oxidized during exhumation and erosion of mountain ranges. By respiring previously sequestered reduced carbon, erosion consumes atmospheric oxygen and produces CO<sub>2</sub>. The balance between these two processes—preservation and respiration—regulates atmospheric composition, Earth-surface redox state, and global climate. Despite this importance, the governing mechanisms remain poorly constrained. To provide new insight, we developed a method that investigates OC composition using bond-strength distributions coupled with radiocarbon ages. Here I highlight a suite of recent results using this approach, and I show that biospheric OC interacts with particles and becomes physiochemically protected during aging, thus promoting preservation. I will discuss how this mechanistic framework can help elucidate why OC preservation—and thus atmospheric composition, Earth-surface redox state, and climate—has varied throughout Earth history.</p>

scholarly journals In situ observations show vertical community structure of pelagic fauna in the eastern tropical North Atlantic off Cape Verde

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
H. J. T. Hoving ◽  
P. Neitzel ◽  
H. Hauss ◽  
S. Christiansen ◽  
R. Kiko ◽  
...  
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Global Climate ◽  
Distribution Patterns ◽  
Cape Verde ◽  
Distribution Data ◽  
Low Oxygen ◽  
Study Region ◽  
Tropical North Atlantic ◽  
Minimum Zone

AbstractDistribution patterns of fragile gelatinous fauna in the open ocean remain scarcely documented. Using epi-and mesopelagic video transects in the eastern tropical North Atlantic, which features a mild but intensifying midwater oxygen minimum zone (OMZ), we established one of the first regional observations of diversity and abundance of large gelatinous zooplankton. We quantified the day and night vertical distribution of 46 taxa in relation to environmental conditions. While distribution may be driven by multiple factors, abundance peaks of individual taxa were observed in the OMZ core, both above and below the OMZ, only above, or only below the OMZ whereas some taxa did not have an obvious distribution pattern. In the eastern eropical North Atlantic, OMZ expansion in the course of global climate change may detrimentally impact taxa that avoid low oxygen concentrations (Beroe, doliolids), but favour taxa that occur in the OMZ (Lilyopsis, phaeodarians, Cydippida, Colobonema, Haliscera conica and Halitrephes) as their habitat volume might increase. While future efforts need to focus on physiology and taxonomy of pelagic fauna in the study region, our study presents biodiversity and distribution data for the regional epi- and mesopelagic zones of Cape Verde providing a regional baseline to monitor how climate change may impact the largest habitat on the planet, the deep pelagic realm.

Seasonal variations in the Indian Ocean along 110°E. I. Hydrological structure of the upper 500 m

1969 ◽  
Vol 20 (1) ◽  
pp. 1 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
Surface Waters ◽  
Water Masses ◽  
Surface Currents ◽  
Temperature Changes ◽  
East Indian ◽  
Hydrological Structure ◽  
The Indian Ocean ◽  
The Tropics ◽  
East Indian Ocean

Tropical and subtropical water masses at surface and subsurface depths were separated by their salinity, temperature, oxygen, and nutrient characteristics. The annual mean depths and latitudinal extent of these water masses were determined. Annual changes in the upper 50 m were generally so small relative to those found in other oceans that advection and mixing must have been less important in their genesis than local climatic changes. There was a barely significant seasonal rhythm in surface phosphate and nitrate, with peak occurrences of each some 6 months apart. At each latitude the permanent thermal discontinuity centred around a particular isotherm varied little in intensity during the year, but rose and fell in accordance with surface currents. The thermocline south of c. 18�S. varied little in depth but greatly in intensity during the summer. The depth of the mixed layer was much less in summer and at all times shallower in the tropics. The depth of this layer was governed more by the accumulation of surface waters by zonal currents and eddies, than by wind stress or convective overturn. Therefore there was little difference from south to north, or month to month, in average nutrient values of this mixed column. The movement of the various surface waters, deduced from salinity and temperature changes during the year, usually agrees with geostrophic currents across 110�E, and ships' observations of surface currents in the south-east Indian Ocean.

The pico-sized Mamiellophyceae and a novel Bathycoccus clade from the summer plankton of Russian Arctic Seas and adjacent waters

2020 ◽  
Author(s):  
Tatiana A Belevich ◽  
Irina A Milyutina ◽  
Galina A Abyzova ◽  
Aleksey V Troitsky
Keyword(s):  
High Throughput Sequencing ◽  
Community Dynamics ◽  
Global Climate ◽  
Atmospheric Oxygen ◽  
18S Rrna Gene ◽  
Anthropogenic Activity ◽  
Marine Biodiversity ◽  
Rrna Gene ◽  
Russian Arctic ◽  
Arctic Seas

Abstract Global climate changes and anthropogenic activity greatly impact Arctic marine biodiversity including phytoplankton which contribute greatly to atmospheric oxygen production. Thus the study of microalgae has rising topicality. Class Mamiellophyceae is an important component of phototrophic picoplankton. To get more knowledge about Mamiellophyceae distribution and diversity special study were performed in such remote areas as the Russian Arctic seas. A metabarcoding of pico-sized Mamiellophyceae was undertaken by high-throughput sequencing of the 18S rRNA gene sequence V4 region from samples collected in July-September 2017 in the Barents, Kara, and Laptev seas, and in the adjacent waters of the Norwegian Sea. Our study is the first to show that Mamiellophyceae among the summer picoplankton of Russian Arctic seas are diverse and represented by 16 algae species/phylotypes. We discovered a new candidate species of Bathycoccus assigned to a new Bathycoccus clade A—uncultured Bathycoccus Kara 2017. It was found that several Micromonas species can co-exist, with M. polaris dominating north of 72°N. The presence of Ostreococcus tauri, O. lucimarinus and O. mediterraneus at high latitudes beyond 65°N was documented for the first time, similar to findings for some other taxa. Our results will be important for obtaining a global view of Mamiellophyceae community dynamics.

Sign in / Sign up

Export Citation Format

Share Document