Ldh activity in Euphausia mucronata and Calanus chilensis: implications for vertical migration behaviour

González, Rodrigo R.

doi:10.1093/plankt/24.12.1349

Cited by 47 publications

(36 citation statements)

References 19 publications

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“…These conditions are generated by high oxygen consumption due to the decomposition of organic matter and slow rates of water renewal by ventilation 48) . The OMZ is an important physical barrier to aerobic respiration 15) , making oxygen levels a critical factor for the pelagic biota 4,20,21,30,47) . The sampling area is characterized by upwelling and a semi-permanent subsurface OMZ related to the Equatorial Subsurface Waters (ESSW) that are transported poleward by the Gunther Current 5,68) (Fig.…”

Section: Site Sampling and Hydrographic Measurementsmentioning

confidence: 99%

Methylotrophic Methanogens in the Water Column of an Upwelling Zone with a Strong Oxygen Gradient Off Central Chile

et al. 2007

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The growing biogeochemical and economic importance of biogenic methane contained in gas hydrates necessitates a better understanding of the microorganisms involved in the last phase of organic matter degradation. Here, the distribution and relative abundance of methylotrophic methane-producing Archaea (mMPA) were studied in an upwelling area off central Chile by rRNA dot blot hybridization. The mMPA were detected mostly during active upwelling periods, and were more abundant in the deeper layer of the water column (>50 m), where they represented ~10% of the prokaryote rRNA extractable from seawater samples in the oxygen minimum zone (OMZ). Significant correlations were found between the concentration of rRNA from mMPA and (i) nitrate concentration (r=−0.54, p=0.0392) and (ii) temperature (r=−0.51, p=0.0267). Enrichment experiments with water samples from the OMZ were carried out to evaluate the cellular viability of mMPA. These experiments showed that some of these Archaea remain viable in the planktonic environment although not essentially associated with fecal pellets or any type of compact macroaggregate. The results suggest that mMPA in the water column come mostly from sediment and that a fraction correspond to psychrophilic varieties of facultative methylotrophs.

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Section: Site Sampling and Hydrographic Measurementsmentioning

confidence: 99%

Methylotrophic Methanogens in the Water Column of an Upwelling Zone with a Strong Oxygen Gradient Off Central Chile

et al. 2007

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“…Interestingly, certain copepod and euphausiid species are able to live within or migrate through the OMZ [15]–[17] and the copepods Calanoides carinatus , Rhincalanus nasutus and Pleuromamma robusta frequently inhabit the OMZ in the Atlantic [11], [18]. Vertical migration through the OMZ is apparently associated with a reduction of respiration rates at lower oxygen partial pressures [19] and a higher activity of the enzyme lactate dehydrogenase (LDH), which indicates anaerobic metabolism [20], [21]. Zooplankton mainly survives aerobically within OMZs [22], but the anaerobic pathway may serve as an additional energy supply to support activity above routine metabolism [21], [23].…”

Section: Introductionmentioning

confidence: 99%

“…Vertical migration through the OMZ is apparently associated with a reduction of respiration rates at lower oxygen partial pressures [19] and a higher activity of the enzyme lactate dehydrogenase (LDH), which indicates anaerobic metabolism [20], [21]. Zooplankton mainly survives aerobically within OMZs [22], but the anaerobic pathway may serve as an additional energy supply to support activity above routine metabolism [21], [23].…”

Section: Introductionmentioning

confidence: 99%

Distribution and Ecophysiology of Calanoid Copepods in Relation to the Oxygen Minimum Zone in the Eastern Tropical Atlantic

et al. 2013

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Oxygen minimum zones (OMZs) affect distribution patterns, community structure and metabolic processes of marine organisms. Due to the prominent role of zooplankton, especially copepods, in the marine carbon cycle and the predicted intensification and expansion of OMZs, it is essential to understand the effects of hypoxia on zooplankton distribution and ecophysiology. For this study, calanoid copepods were sampled from different depths (0–1800 m) at eight stations in the eastern tropical Atlantic (3°47′N to 18°S) during three expeditions in 2010 and 2011. Their horizontal and vertical distribution was determined and related to the extent and intensity of the OMZ, which increased from north to south with minimum O2 concentrations (12.7 µmol kg−1) in the southern Angola Gyre. Calanoid copepod abundance was highest in the northeastern Angola Basin and decreased towards equatorial regions as well as with increasing depth. Maximum copepod biodiversity was observed in the deep waters of the central Angola Basin. Respiration rates and enzyme activities were measured to reveal species-specific physiological adaptations. Enzyme activities of the electron transport system (ETS) and lactate dehydrogenase (LDH) served as proxies for aerobic and anaerobic metabolic activity, respectively. Mass-specific respiration rates and ETS activities decreased with depth of occurrence, consistent with vertical changes in copepod body mass and ambient temperature. Copepods of the families Eucalanidae and Metridinidae dominated within the OMZ. Several of these species showed adaptive characteristics such as lower metabolic rates, additional anaerobic activity and diel vertical migration that enable them to successfully inhabit hypoxic zones.

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“…However, this vertical movement of zooplankton is affected, among other factors, by displacement of the oxygen minimum zone (OMZ, <0.5 mL L -1 ) within the euphotic zone establishing a strict physiological limit of vertical movement (Morales et al, 1996;González & Quiñones, 2002) forcing the aggregation of planktonic organisms above 50 m depth (Escribano & Hidalgo, 2000). An alternative mechanism for retention would be the result of the spatial and temporal variability on the nearshore circulation.…”

Section: Introductionmentioning

confidence: 99%

Fish larvae retention linked to abrupt bathymetry at Mejillones Bay (northern Chile) during coastal upwelling events

Rojas¹,

Landaeta²

2014

lajar

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ABSTRACT. The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax), associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia) and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus), associated with the thermocline (12°C), and finally, larvae of the families Myctophidae (Diogenichthys atlanticus) and Bathylagidae (Bathylagus nigrigenys), associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.

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Ldh activity in Euphausia mucronata and Calanus chilensis: implications for vertical migration behaviour

Cited by 47 publications

References 19 publications

Methylotrophic Methanogens in the Water Column of an Upwelling Zone with a Strong Oxygen Gradient Off Central Chile

Methylotrophic Methanogens in the Water Column of an Upwelling Zone with a Strong Oxygen Gradient Off Central Chile

Distribution and Ecophysiology of Calanoid Copepods in Relation to the Oxygen Minimum Zone in the Eastern Tropical Atlantic

Fish larvae retention linked to abrupt bathymetry at Mejillones Bay (northern Chile) during coastal upwelling events

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