scholarly journals A novel approach reveals high zooplankton standing stock deep in the sea

2016 ◽  
Vol 13 (22) ◽  
pp. 6261-6271 ◽  
Author(s):  
Alexander Vereshchaka ◽  
Galina Abyzova ◽  
Anastasia Lunina ◽  
Eteri Musaeva ◽  
Tracey Sutton

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. We have made several new discoveries about the Atlantic, which likely apply to the world ocean. First, multivariate analysis showed that depth and Chl were the basic factors affecting the wet biomass of the main plankton groups. Wet biomass of all major groups was significantly correlated with Chl. Second, zooplankton biomass in the upper bathypelagic domain is higher than expected. Third, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, suggest that the contribution of the deep-ocean pelagic fauna for biogeochemical cycles may be more important than previously thought.

2016 ◽  
Author(s):  
Alexander Vereshchaka ◽  
Galina Abyzova ◽  
Anastasia Lunina ◽  
Eteri Musaeva ◽  
Tracey T. Sutton

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. In so doing we have made several new discoveries about the Atlantic, which likely apply to the World Ocean. First, zooplankton biomass in the upper bathypelagic domain is higher than expected, representing an inverted biomass pyramid. Second, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, revise our perspective on the role of the deep-pelagic fauna in oceanic biogeochemical cycling.


2020 ◽  
Author(s):  
Yona Silvy ◽  
Eric Guilyardi ◽  
Jean-Baptiste Sallée ◽  
Paul Durack

<p>The World Ocean is rapidly changing, with global and regional modification of temperature and salinity evident at the surface and depth. These changes have widespread and irreversible impacts including sea-level rise, changes to the oxygen and carbon contents of the ocean interior, or changing habitats, diversity and resilience of ecosystems. While the most pronounced temperature and salinity changes are located in the upper few hundred metres, changes in water-masses at depth are already observed and will likely strengthen and persist in the future as water-masses form at the surface and propagate in the deep ocean along density surfaces, storing the anthropogenic signal away from the atmosphere for decades to millennia. Here, using 11 climate models, we define when anthropogenic temperature and salinity changes are expected to emerge from natural background variability in the ocean interior. On a basin-scale zonal average, the model simulations predict that in 2020, 20–55% of the Atlantic, Pacific and Indian basins have an emergent anthropogenic signal; reaching 40–65% in 2050, and 55–80% in 2080. The well-ventilated Southern Ocean water-masses emerge very rapidly, as early as the 1980s-1990s, while the Northern Hemisphere emerges in the 2010s to 2030s. Additionally, dedicated idealized simulations of the IPSL coupled climate model are examined to study the role of each separate surface forcing on the time scales associated with the patterns of temperature and salinity change under a global warming scenario, and the influence of excess versus redistributed heat and salt. Our results highlight the importance of maintaining and augmenting an ocean observing system capable of detecting and monitoring anthropogenic changes. </p>


2005 ◽  
Vol 32 (2) ◽  
pp. 265-280 ◽  
Author(s):  
Stuart A. Cunningham

The Discovery Investigations of the 1930s provided a compelling description of the main elements of the Southern Ocean circulation. Over the intervening years, this has been extended to include ideas on ocean dynamics based on physical principles. In the modern description, the Southern Ocean has two main circulations that are intimately linked: a zonal (west-east) circumpolar circulation and a meridional (north-south) overturning circulation. The Antarctic Circumpolar Current transports around 140 million cubic metres per second west to east around Antarctica. This zonal circulation connects the Atlantic, Indian and Pacific Oceans, transferring and blending water masses and properties from one ocean basin to another. For the meridional circulation, a key feature is the ascent of waters from depths of around 2,000 metres north of the Antarctic Circumpolar Current to the surface south of the Current. In so doing, this circulation connects deep ocean layers directly to the atmosphere. The circumpolar zonal currents are not stable: meanders grow and separate, creating eddies and these eddies are critical to the dynamics of the Southern Ocean, linking the zonal circumpolar and meridional circulations. As a result of this connection, a global three-dimensional ocean circulation exists in which the Southern Ocean plays a central role in regulating the Earth's climate.


2012 ◽  
Vol 5 (2) ◽  
pp. 1077-1106 ◽  
Author(s):  
E. T. Buitenhuis ◽  
M. Vogt ◽  
R. Moriarty ◽  
N. Bednaršek ◽  
S. C. Doney ◽  
...  

Abstract. We present a summary of biomass data for 11 Plankton Functional Types (PFTs) plus phytoplankton pigment data, compiled as part of the MARine Ecosystem biomass DATa (MAREDAT) initiative. The goal of the MAREDAT initiative is to provide global gridded data products with coverage of all biological components of the global ocean ecosystem. This special issue is the first step towards achieving this. The PFTs presented here include picophytoplankton, diazotrophs, coccolithophores, Phaeocystis, diatoms, picoheterotrophs, microzooplankton, foraminifers, mesozooplankton, pteropods and macrozooplankton. All variables have been gridded onto a World Ocean Atlas (WOA) grid (1° × 1° × 33 vertical levels × monthly climatologies). The data show that (1) the global total heterotrophic biomass (2.0–6.4 Pg C) is at least as high as the total autotrophic biomass (0.5–2.6 Pg C excluding nanophytoplankton and autotrophic dinoflagellates), (2) the biomass of zooplankton calcifiers (0.9–2.3 Pg C) is substantially higher than that of coccolithophores (0.01–0.14 Pg C), (3) patchiness of biomass distribution increases with organism size, and (4) although zooplankton biomass measurements below 200 m are rare, the limited measurements available suggest that Bacteria and Archaea are not the only heterotrophs in the deep sea. More data will be needed to characterize ocean ecosystem functioning and associated biogeochemistry in the Southern Hemisphere and below 200 m. Microzooplankton database: doi:10.1594/PANGAEA.779970.


2001 ◽  
Vol 58 (8) ◽  
pp. 1501-1515 ◽  
Author(s):  
Brian J Pyper ◽  
Franz J Mueter ◽  
Randall M Peterman ◽  
David J Blackbourn ◽  
Chris C Wood

We examined spatial patterns of covariation in indices of survival rate (residuals from the best-fit stock- recruitment curve) across four decades among 43 wild pink salmon (Oncorhynchus gorbuscha) stocks from 14 geographical regions in Washington, British Columbia, and Alaska. We found strong evidence of positive covariation among stocks within each region and between certain adjacent regions (e.g., correlations from 0.3 to 0.7) but no evidence of covariation between stocks of distant regions (e.g., separated by 1000 km or more). This suggests that important environmental processes affecting temporal variation in survival rates of pink salmon from spawners to recruits operate at regional spatial scales rather than at the larger ocean basin scale. Based on limited fry abundance data, we found that this covariation in spawner-to-recruit survival rates may be strongly influenced by marine processes.


1993 ◽  
Vol 67 (S35) ◽  
pp. 1-35 ◽  
Author(s):  
Louie Marincovich

The marine molluscan fauna of the Prince Creek Formation near Ocean Point, northern Alaska, is of Danian age. It is the only diverse and abundant Danian molluscan fauna known from the Arctic Ocean realm, and is the first evidence for an indigenous Paleocene shallow-water biota within a discrete Arctic Ocean Basin faunal province.A high percentage of endemic species, and two endemic genera, emphasize the degree to which the Arctic Ocean was geographically isolated from the world ocean during the earliest Tertiary. Many of the well-preserved Ocean Point mollusks, however, also occur in Danian faunas of the North American Western Interior, the Canadian Arctic Islands, Svalbard, and northwestern Europe, and are the basis for relating this Arctic Ocean fauna to that of the Danian world ocean.The Arctic Ocean was a Danian refugium for some genera that became extinct elsewhere during the Jurassic and Cretaceous. At the same time, this nearly landlocked ocean fostered the evolution of new taxa that later in the Paleogene migrated into the world ocean by way of the northeastern Atlantic. The first Cenozoic occurrences are reported for the bivalves Integricardium (Integricardium), Oxytoma (Hypoxytoma), Placunopsis, Tancredia (Tancredia), and Tellinimera, and the oldest Cenozoic records given for the bivalves Gari (Garum), Neilo, and Yoldia (Cnesterium). Among the 25 species in the molluscan fauna are four new gastropod species, Amauropsis fetteri, Ellipsoscapha sohli, Mathilda (Fimbriatella) amundseni, and Polinices (Euspira) repenningi, two new bivalve genera, Arcticlam and Mytilon, and 15 new bivalve species, Arcticlam nanseni, Corbula (Caryocorbula) betsyae, Crenella kannoi, Cyrtodaria katieae, Gari (Garum) brouwersae, Integricardium (Integricardium) keenae, Mytilon theresae, Neilo gryci, Nucula (Nucula) micheleae, Nuculana (Jupiteria) moriyai, Oxytoma (Hypoxytoma) hargrovei, Placunopsis rothi, Tancredia (Tancredia) slavichi, Tellinimera kauffmani, and Yoldia (Cnesterium) gladenkovi.


2019 ◽  
Vol 70 (3) ◽  
pp. 345 ◽  
Author(s):  
K. K. Karati ◽  
G. Vineetha ◽  
T. V. Raveendran ◽  
P. K. Dineshkumar ◽  
K. R. Muraleedharan ◽  
...  

The Arabian Sea, a major tropical ocean basin in the northern Indian Ocean, is one of the most productive regions in the global ocean. Although the classical Arabian Sea ‘paradox’ describes the geographical and seasonal invariability in zooplankton biomass in this region, the effect of the Lakshadweep low (LL), a regional-scale physical process, on the zooplankton community has not yet been evaluated. The LL, characterised by low sea surface height and originating around the vicinity of the Lakshadweep islands during the mid-summer monsoon, is unique to the Arabian Sea. The present study investigated the effect of the LL on the zooplankton community. The LL clearly had a positive effect, with enhanced biomass and abundance in the mixed-layer depth of the LL region. Copepods and chaetognaths formed the dominant taxa, exhibiting strong affinity towards the physical process. Of the 67 copepod species observed, small copepods belonging to the families Paracalanidae, Clausocalanidae, Calanidae, Oncaeidae and Corycaeidae dominated the LL region. Phytoplankton biomass (chlorophyll-a) was the primary determinant influencing the higher preponderance of the copepod community in this region.


Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Achim Randelhoff ◽  
Laurent Oziel ◽  
Philippe Massicotte ◽  
Guislain Bécu ◽  
Martí Galí ◽  
...  

During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters originating from the Canadian archipelago. Winter overturning and thus nutrient replenishment was hampered by strong haline stratification in the Arctic domain, whereas close to the West Greenland shelf, weak stratification permitted winter mixing with high-nitrate Atlantic-derived waters. Using a space-for-time approach, we linked upper ocean dynamics to the phytoplankton bloom trailing the retreating ice edge. In a band of 60 km (or 15 days) around the ice edge, the upper ocean was especially affected by a freshened surface layer. Light climate, as evidenced by deep 0.415 mol m–2 d–1 isolumes, and vertical mixing, as quantified by shallow mixing layer depths, should have permitted significant net phytoplankton growth more than 100 km into the pack ice at ice concentrations close to 100%. Yet, under-ice biomass was relatively low at 20 mg chlorophyll-a m–2 and depth-integrated total chlorophyll-a (0–80 m) peaked at an average value of 75 mg chlorophyll-a m–2 only around 10 days after ice retreat. This phenological peak may hence have been the delayed result of much earlier bloom initiation and demonstrates the importance of temporal dynamics for constraints of Arctic marine primary production.


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