scholarly journals The carbon and nitrogen budget of Desmophyllum dianthus—a voracious cold-water coral thriving in an acidified Patagonian fjord

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12609
Author(s):  
Sandra R. Maier ◽  
Carin Jantzen ◽  
Jürgen Laudien ◽  
Verena Häussermann ◽  
Günter Försterra ◽  
...  
Keyword(s):  
Food Deprivation ◽  
Cold Water ◽  
N Uptake ◽  
Substantial Reduction ◽  
Ammonium Excretion ◽  
N Losses ◽  
Carbon And Nitrogen ◽  
Desmophyllum Dianthus ◽  
C And N ◽  
Water Coral

In the North Patagonian fjord region, the cold-water coral (CWC) Desmophyllum dianthus occurs in high densities, in spite of low pH and aragonite saturation. If and how these conditions affect the energy demand of the corals is so far unknown. In a laboratory experiment, we investigated the carbon and nitrogen (C, N) budget of D. dianthus from Comau Fjord under three feeding scenarios: (1) live fjord zooplankton (100–2,300 µm), (2) live fjord zooplankton plus krill (>7 mm), and (3) four-day food deprivation. In closed incubations, C and N budgets were derived from the difference between C and N uptake during feeding and subsequent C and N loss through respiration, ammonium excretion, release of particulate organic carbon and nitrogen (POC, PON). Additional feeding with krill significantly increased coral respiration (35%), excretion (131%), and POC release (67%) compared to feeding on zooplankton only. Nevertheless, the higher C and N losses were overcompensated by the threefold higher C and N uptake, indicating a high assimilation and growth efficiency for the krill plus zooplankton diet. In contrast, short food deprivation caused a substantial reduction in respiration (59%), excretion (54%), release of POC (73%) and PON (87%) compared to feeding on zooplankton, suggesting a high potential to acclimatize to food scarcity (e.g., in winter). Notwithstanding, unfed corals ‘lost’ 2% of their tissue-C and 1.2% of their tissue-N per day in terms of metabolism and released particulate organic matter (likely mucus). To balance the C (N) losses, each D. dianthus polyp has to consume around 700 (400) zooplankters per day. The capture of a single, large krill individual, however, provides enough C and N to compensate daily C and N losses and grow tissue reserves, suggesting that krill plays an important nutritional role for the fjord corals. Efficient krill and zooplankton capture, as well as dietary and metabolic flexibility, may enable D. dianthus to thrive under adverse environmental conditions in its fjord habitat; however, it is not known how combined anthropogenic warming, acidification and eutrophication jeopardize the energy balance of this important habitat-building species.

scholarly journals Physiological response of the cold-water coralDesmophyllum dianthusto thermal stress and ocean acidification

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1606 ◽  
Author(s):  
Andrea Gori ◽  
Christine Ferrier-Pagès ◽  
Sebastian J. Hennige ◽  
Fiona Murray ◽  
Cécile Rottier ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Ocean Acidification ◽  
Cold Water ◽  
Ammonium Excretion ◽  
Ambient Temperatures ◽  
Metabolic Substrates ◽  
Mixed Use ◽  
Desmophyllum Dianthus ◽  
Excretion Rates ◽  
Water Coral

Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coralDesmophyllum dianthusmaintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology ofD. dianthusis more sensitive to thermal than pCO2stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species.

scholarly journals Carbon, nitrogen and sulfur (CNS) status and dynamics in Amazon basin upland soils, Brazil

2019 ◽  
Author(s):  
Jörg Matschullat ◽  
Roberval Monteiro Bezerra de Lima ◽  
Sophie F. von Fromm ◽  
Solveig Pospiech ◽  
Andrea M. Ramos ◽  
...  
Keyword(s):  
Climate Change ◽  
Amazon Basin ◽  
Forest Canopy ◽  
Regional Climate ◽  
Mineral Soil ◽  
Regional Climate Change ◽  
Wet Season ◽  
N Losses ◽  
Carbon And Nitrogen ◽  
C And N

Abstract. Given the dimensions of the Amazon basin (7.5 million km2), its internal dynamics, increasing anthropogenic strain on this large biome, and its global role as one of two continental biospheric tipping elements, it appears crucial to have data-based knowledge on carbon and nitrogen concentrations and pools as well as on possible intra-annual dynamics. We quantified carbon (Ct, Corg), nitrogen (N) and sulfur (S) concentrations in litter (ORG) and mineral soil material (TOP 0–20 cm, BOT 30–50 cm) of upland (terra firme) oxisols across Amazonas state and present a first pool calculation. Data are based on triplicate seasonal sampling at 29 sites (forest and post-forest) within the binational project EcoRespira-Amazon (ERA). Repeated sampling increased data accuracy and allows for interpreting intra-annual (seasonal) and climate-change related dynamics. Extreme conditions between the dry season in 2016 and the subsequent wet season (ENSO-related) show differences more clearly. Median CNS in the Amazon basin TOP soils (Ct 1.9, Corg 1.6, N 0.15, S 0.03 wt-% under forest canopy) as well as Corg / N ratios show concentrations similar to European soils (FOREGS, GEMAS). TOP Ct concentrations ranged from 1.02 to 3.29 wt-% (medianForest 2.17 wt-%; medianPost-Forest 1.75 wt-%), N from 0.088 to 0.233 wt-% (medianForest 0.17 wt-%; medianPost-Forest 0.09 wt-%) and S from 0.012 to 0.051 wt.-% (medianForest 0.03 wt.-%; medianPost-Forest 0.02 wt-%). Corg / N ratios ranged from 6 to 14 (median 10). A first pool calculation (hectare-based) illustrates forest versus post-forest changes. The elements are unevenly distributed in the basin with generally higher CNS values in the central part (Amazonas graben) as compared to the southern part of the basin. Deforestation and drought conditions lead to C and N losses – within 50 years after deforestation, C and N losses average 10 to 15 %. Regional climate change with increased drought will likely speed up carbon and nitrogen losses.

Mass die-off of the cold-water coral Desmophyllum dianthus in the Chilean Patagonian fjord region

2014 ◽  
Vol 90 (3) ◽  
pp. 895-899 ◽  
Author(s):  
Günter Försterra ◽  
Vreni Häussermann ◽  
Jürgen Laudien ◽  
Carin Jantzen ◽  
Javier Sellanes ◽  
...  
Keyword(s):  
Cold Water ◽  
Desmophyllum Dianthus ◽  
Water Coral

scholarly journals First in situ estimations of small phytoplankton carbon and nitrogen uptake rates in the Kara, Laptev, and East Siberian seas

2018 ◽  
Vol 15 (18) ◽  
pp. 5503-5517 ◽  
Author(s):  
P. Sadanandan Bhavya ◽  
Jang Han Lee ◽  
Ho Won Lee ◽  
Jae Joong Kang ◽  
Jae Hyung Lee ◽  
...  
Keyword(s):  
Sea Ice ◽  
Nitrogen Uptake ◽  
Isotope Labeling ◽  
N Uptake ◽  
The Arctic ◽  
Carbon And Nitrogen ◽  
Uptake Rates ◽  
Small Phytoplankton ◽  
C And N

Abstract. Carbon and nitrogen uptake rates by small phytoplankton (0.7–5 µm) in the Kara, Laptev, and East Siberian seas in the Arctic Ocean were quantified using in situ isotope labeling experiments; this research, which was novel and part of the NABOS (Nansen and Amundsen Basins Observational System) program, took place from 21 August to 22 September 2013. The depth-integrated carbon (C), nitrate (NO3-), and ammonium (NH4+) uptake rates by small phytoplankton ranged from 0.54 to 15.96 mg C m−2 h−1, 0.05 to 1.02 mg C m−2 h−1, and 0.11 to 3.73 mg N m−2 h−1, respectively. The contributions of small phytoplankton towards the total C, NO3-, and NH4+ varied from 25 % to 89 %, 31 % to 89 %, and 28 % to 91 %, respectively. The turnover times for NO3- and NH4+ by small phytoplankton found in the present study indicate the longer residence times (years) of the nutrients in the deeper waters, particularly for NO3-. Additionally, the relatively higher C and N uptake rates by small phytoplankton obtained in the present study from locations with less sea ice concentration indicate the possibility that small phytoplankton thrive under the retreat of sea ice as a result of warming conditions. The high contributions of small phytoplankton to the total C and N uptake rates suggest the capability of small autotrophs to withstand the adverse hydrographic conditions introduced by climate change.

scholarly journals Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Maria Kernecker ◽  
Joann K. Whalen ◽  
Robert L. Bradley
Keyword(s):  
Vegetation Management ◽  
Riparian Buffers ◽  
Litter Type ◽  
Nitrogen Transformations ◽  
Microcosm Experiment ◽  
Reed Canarygrass ◽  
N Losses ◽  
Carbon And Nitrogen ◽  
C And N ◽  
Native Tree Species

Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N) mineralization, increasing carbon (C) and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect ofAporrectodea turgidaon the decomposition of 3 litter types (deciduous leaves, reed canarygrass, and soybean stem residue). Earthworms increased CO2and N2O losses from microcosms with soybean residue, by 112% and 670%, respectively, but reduced CO2and N2O fluxes from microcosms with reed canarygrass by 120% and 220%, respectively. Litter type controlled the CO2flux (soybean ≥ deciduous-mix litter = reed canarygrass > no litter) and the N2O flux (soybean ≥ no litter ≥ reed canarygrass > deciduous-mix litter). However, in the presence of earthworms, there was a slight increase in C and N gaseous losses of C and N relative to their losses via leachate, across litter treatments. We conclude that litter type determines the earthworm-mediated decomposition effect, highlighting the importance of vegetation management in controlling C and N losses from riparian buffers to the environment.

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