1,721,043 research outputs found
Biodiversity component effects on macroalgal primary productivity
No full textThe objective of this study was to disentangle the effects of components of diversity and primary productivity within subarctic intertidal macroalgal communities. This study was done using common abundant macroalgal species occurring naturally together in the mid-low intertidal zone (48°37'42.5'' N, 68°11'55.7'' W) of the St. Lawrence Estuary, near the municipality of Sainte-Flavie (Quebec, Canada). We used two canopy species (genus Fucus sp.) and four of their associated subcanopy species to build realistic assemblages having six different levels of richness, two levels of evenness, and five levels of abundance. The productivity variables of respiration (R), net (NPP), and gross primary production (GPP) of these assemblages were measured in mesocosms (0.09 m²) during summer 2012 and 2013 as mmol CO₂ m⁻² h⁻¹ per gram wet weight of macroalgae
Abundances of intertidal macro-species measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of intertidal epibenthic macro-species abundances. Abundances were measured two weeks after reducing eelgrass density (Period T1), then nutrients were added to the sediments and shades were added above the bed. Abundances were measured three weeks later (Period T2), then shades were taken down. Final abundances were measured five weeks later (Period T3). Epibenthos was collected using mesh bags (mesh size of 500 µm, diameter about 18 cm), each individual collected was identified then sifted through a series of sieves to determine biomass in ash free dry weight (AFDW; see doi:10.1594/PANGAEA.931116)
Eelgrass shoot density measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of shading and sediment nutrient enrichment on the response of Zostera marina L. shoot density. Shoot density was evaluated using counts from three hoops of 20-cm diameter. Shoot density was measured before starting the experiment (T0), five weeks after the start of the experiment (T2) and at the end of the experiment after ten weeks (T3)
Macro-species taxonomy measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of intertidal epibenthic macro-species. Epibenthos was collected using mesh bags (mesh size of 500 µm, diameter about 18 cm). This dataset reports all species identified through the experiment and their taxonomic classification
Biomass (dry weight) of epiphytic microalgae measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of microalgal epiphyte load on eelgrass leaves. We estimated the epiphyte (microalgae) load on eelgrass by scraping eelgrass leaves with a microscope slide under filtered seawater. During Period T1, we selected and scraped the leaves of three randomly selected shoots. We then filtered the water containing the scraped epiphytes through preweighed GF/F filters, and we assessed the epiphyte load as the dry weight of epiphytes divided by the dry weight of the collected scraped shoots
Relative eelgrass leaf elongation and microalgal epiphyte load on eelgrass leaf measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of eelgrass relative leaf elongation (RLE) and of microalgal epiphyte load on leaves. REL was evaluated once, as a proxy for growth, using five shoots per plot that were each marked with a reference hole at the top of the sheath using a pushpin marked at the end of Period T1 (two weeks after reducing eelgrass density and at the same time than adding nutrients sediment enrichment and shades). After 19 days, we collected the shoots and brought them back to the lab where leaf elongation was measured as the displacement of the mark relative to the reference mark on the oldest nongrowing leaf (Olesen & Sand-Jensen 1994). Total leaf elongation was then divided by sheath length and the number of days of elongation. We estimated the epiphyte (microalgae) load on eelgrass by scraping the leaves of one randomly selected shoot; we then filtered the water containing the epiphytes on GF/F filters that were then kept wrapped in aluminum foil at -80 °C until analysis. Epiphyte load was assessed using chlorophyll extraction with 90% acetone, following Parsons et al. (1984). Calculated chlorophyll weight was then divided by shoot dry weight
Soluble sugar and starch content in eelgrass leaves and root-rhizomes measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of Z. marina leaf and root-rhizomes carbohydrates (soluble sugar and starch content). Soluble sugars were extracted using 80%, centrifuged, treated with phenol (supernatant) and sulfuric acid then measured using spectrophotometry. Soluble sugars dry weight was calculated using glucose-standard curves. Enzymatic digestion of the remaining pellet was used to determine starch concentrations and measured using spectrophotometry. For full method, see related article (doi:10.3354/meps13546)
Eelgrass biomass (dry weight) measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of intertidal epibenthic macro-species abundances. Abundances were measured two weeks after reducing eelgrass density (Period T1), then nutrients were added to the sediments and shades were added above the bed. Abundances were measured three weeks later (Period T2), then shades were taken down. Final abundances were measured five weeks later (Period T3). Epibenthos was collected using mesh bags (mesh size of 500 µm, diameter about 18 cm). Shoots collected using this mehod were dried then dry weight was measured
Eelgrass biomass (dry weight) distribution measured through a multi-factorial in situ experiment of 10 weeks in a eelgrass bed in St. Lawrence Estuary (Baie-Saint-Ludger, Canada)
No full textWe evaluated single and interactive effects of density reduction of Zostera marina L., a habitat-forming species, shading, and sediment nutrient enrichment on the response of Z. marina and its associated epifauna over a 10-week experiment during the summer of 2015. Before the experiment was started (Period T0), above-ground eelgrass shoot biomass was evaluated using the shoots collected from 10 cells of 10 x 10 cm while applying the Z. marina density reduction
Occurrence and abundance records of macrobenthic organisms collected from grab samples taken in Canadian Arctic seas between 1955 and 1975
No full textThis dataset is a component of the PAN-Arctic data collection of benthic BIOtas (PANABIO) and has been collated during the Census of Marine Life project Arctic Ocean Diversity (ArcOD; http://www.arcodiv.org/). It contains a total of 7,203 occurrence and abundance records of 793 macrobenthic taxa (species to genus level) identified in 235 grab samples taken at 235 stations located in various Canadian Arctic seas at water depths of 1–970 m during 24 cruises between 1955 and 1975. The dataset is also available in a PostgreSQL-based data warehouse that can be accessed and queried through an open-access frontend web service at https://critterbase.awi.de/panabio
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