Zooplankton ecology in the eastern tropical Pacific oxygen minimum zone above a seamount: 1. General trends

Saltzman, Jennifer; Wishner, Karen F.

doi:10.1016/s0967-0637(97)00007-1

Cited by 54 publications

(27 citation statements)

References 37 publications

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“…If the O 2 concentration drops below 4 mmol kg À1 the remineralization of organic matter in the deep ocean is assumed to follow the denitrification pathway and thus does not consume any molecular oxygen. This is in line with the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP) 2 protocol and field data on zooplankton abundance [Saltzman and Wishner, 1997]. While anoxic conditions do not occur for preindustrial model conditions, they do occur during time-dependent model scenarios when large changes in oceanic overturning are assumed (to be investigated later on).…”

supporting

confidence: 80%

Quantitative interpretation of atmospheric carbon records over the last glacial termination

Köhler

Fischer

Munhoven

et al. 2005

Global Biogeochemical Cycles

139

191

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[1] The glacial/interglacial rise in atmospheric pCO 2 is one of the best known changes in paleoclimate research, yet the cause for it is still unknown. Forcing the coupled oceanatmosphere-biosphere box model of the global carbon cycle BICYCLE with proxy data over the last glacial termination, we are able to quantitatively reproduce transient variations in pCO 2 and its isotopic signatures (d 13 C, D 14 C) observed in natural climate archives. The sensitivity of the Box model of the Isotopic Carbon cYCLE (BICYCLE) to high or low latitudinal changes is comparable to other multibox models or more complex ocean carbon cycle models, respectively. The processes considered here ranked by their contribution to the glacial/interglacial rise in pCO 2 in decreasing order are: the rise in Southern Ocean vertical mixing rates (>30 ppmv), decreases in alkalinity and carbon inventories (>30 ppmv), the reduction of the biological pump ($20 ppmv), the rise in ocean temperatures (15-20 ppmv), the resumption of ocean circulation (15-20 ppmv), and coral reef growth (<5 ppmv). The regrowth of the terrestrial biosphere, sea level rise and the increase in gas exchange through reduced sea ice cover operate in the opposite direction, decreasing pCO 2 during Termination I by $30 ppmv. According to our model the sequence of events during Termination I might have been the following: a reduction of aeolian iron fertilization in the Southern Ocean together with a breakdown in Southern Ocean stratification, the latter caused by rapid sea ice retreat, trigger the onset of the pCO 2 increase. After these events the reduced North Atlantic Deep Water (NADW) formation during the Heinrich 1 event and the subsequent resumption of ocean circulation at the beginning of the Bølling-Allerød warm interval are the main processes determining the atmospheric carbon records in the subsequent time period of Termination I. We further deduce that a complete shutdown of the NADW formation during the Younger Dryas was very unlikely. Changes in ocean temperature and the terrestrial carbon storage are the dominant processes explaining atmospheric d 13 C after the Bølling-Allerød warm interval.Citation: Köhler, P., H. Fischer, G. Munhoven, and R. E. Zeebe (2005), Quantitative interpretation of atmospheric carbon records over the last glacial termination, Global Biogeochem. Cycles, 19, GB4020,

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supporting

confidence: 80%

Quantitative interpretation of atmospheric carbon records over the last glacial termination

Köhler

Fischer

Munhoven

et al. 2005

Global Biogeochemical Cycles

139

191

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“…The biomass and production values obtained for the three most abundant species of copepod (> 300 µm) around the SPSPA showed a similar pattern to that seen in studies of biomass of zooplankton communities in the vicinity of seamounts (Saltzman and Wishner 1997, Martin and Nellen 2004, Martin and Christiansen 2009. The biomass enrichment and increased production around seamounts are of great importance for higher trophic levels, such as the small and mediumsized pelagic fish that feed on this high primary productivity, which are subsequently captured by larger species such as tuna (Sund et al 1981).…”

Section: Biomass and Productionsupporting

confidence: 78%

Copepod distribution and production in a Mid-Atlantic Ridge archipelago

Melo

Júnior

Macêdo

et al. 2014

An. Acad. Bras. Ciênc.

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The Saint Peter and Saint Paul Archipelago (SPSPA) are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA), with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m -3 , and differences were also found between the first perimeter (first circular distance band) and the others. The total biomass varied from 15.25 to 524.50 10 -3 mg C m -3 and production from 1.19 to 22.04 10 -3 mg C m -3 d -1 . The biomass and production of Undinula vulgaris (Dana, 1849), Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849) showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

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“…Some species are virtually excluded from the OMZ, while others are able to stay or cross it (Longhurst, 1967;Herring et al, 1998;Gonzalez and Quiñones, 2002). Most zooplankton taxa show minimum abundances in the core of the OMZ, with higher abundances at the lower OMZ interface (Sameoto, 1986;Wishner et al, 1995;Böttger-Schnack, 1996;Saltzman and Wishner, 1997a). A local maximum in zooplankton abundance or biomass at the lower OMZ interface seems to be a unique feature of OMZ regions.…”

Section: Changes In Spatial Distributionmentioning

confidence: 99%

“…A local maximum in zooplankton abundance or biomass at the lower OMZ interface seems to be a unique feature of OMZ regions. Different species-specific tolerances to hypoxic conditions influence zooplankton community composition in areas affected by OMZ (Saltzman and Wishner, 1997a). In the Arabian Sea and in the California Current, zooplankton abundance and biomass decrease sharply when the oxygen concentration falls below 0.2 mL O 2 L −1 (Longhurst, 1967;Böttger-Schnack, 1996;Saltzman and Wishner, 1997a).…”

Section: Changes In Spatial Distributionmentioning

confidence: 99%

Impacts of hypoxia on the structure and processes in pelagic communities (zooplankton, macro-invertebrates and fish)

et al. 2010

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Abstract. Dissolved oxygen (DO) concentration in the water column is an environmental parameter that is crucial for the successful development of many pelagic organisms. Hypoxia tolerance and threshold values are species-and stagespecific and can vary enormously. While some fish species may suffer from oxygen values of less than 3 mL O 2 L −1 through impacted growth, development and behaviour, other organisms such as euphausiids may survive DO levels as low as 0.1 mL O 2 L −1 . A change in the average or the range of DO may have significant impacts on the survival of certain species and hence on the species composition in the ecosystem with consequent changes in trophic pathways and productivity.Evidence for the deleterious effects of oxygen depletion on pelagic species is scarce, particularly in terms of the effect of low oxygen on development, recruitment and patterns of migration and distribution. While planktonic organisms have to cope with variable DOs and exploit adaptive mechanisms, nektonic species may avoid areas of unfavourable DO and develop adapted migration strategies. Planktonic organisms may only be able to escape vertically, above or beneath the Oxygen Minimum Zone (OMZ). In shallow areas only the surface layer can serve as a refuge, but in deep waters many organisms have developed vertical migration strategies to use, pass through and cope with the OMZ.Correspondence to: W. Ekau (wekau@zmt-bremen.de) This paper elucidates the role of DO for different taxa in the pelagic realm and the consequences of low oxygen for foodweb structure and system productivity. We describe processes in two contrasting systems, the semi-enclosed Baltic Sea and the coastal upwelling system of the Benguela Current to demonstrate the consequences of increasing hypoxia on ecosystem functioning and services.

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Zooplankton ecology in the eastern tropical Pacific oxygen minimum zone above a seamount: 1. General trends

Cited by 54 publications

References 37 publications

Quantitative interpretation of atmospheric carbon records over the last glacial termination

Quantitative interpretation of atmospheric carbon records over the last glacial termination

Copepod distribution and production in a Mid-Atlantic Ridge archipelago

Impacts of hypoxia on the structure and processes in pelagic communities (zooplankton, macro-invertebrates and fish)

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