Egg production and hatching success of Calanus chilensis and Acartia tonsa in the northern Chile upwelling zone (23°S), Humboldt Current System

Ruz, Paula M.; Hidalgo, Pamela; Yáñez, Sonia; Escribano, Rubén; Keister, Julie E.

doi:10.1016/j.jmarsys.2015.03.007

Cited by 18 publications

(15 citation statements)

References 71 publications

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“…It seems that upwelling, through low temperature, oxygen and also through low pH, can affect the fitness of these planktonic grazers. In fact, temperature and oxygen have been recognized as critical factors controlling body size [37,51,52] and physiological rates of pelagic copepods, respectively [53,54]. Egg production is a particularly sensitive physiological trait, since this is considered an approach to estimate population growth or copepod secondary production [44,55].…”

Section: Discussionmentioning

confidence: 99%

Upwelling modulation of functional traits of a dominant planktonic grazer during “warm-acid” El Niño 2015 in a year-round upwelling area of Humboldt Current

et al. 2019

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Climate change is expected to exacerbate upwelling intensity and natural acidification in Eastern Boundaries Upwelling Systems (EBUS). Conducted between January-September 2015 in a nearshore site of the northern Humboldt Current System directly exposed to year-round upwelling episodes, this study was aimed at assessing the relationship between upwelling mediated pH-changes and functional traits of the numerically dominant planktonic copepod-grazer Acartia tonsa (Copepoda). Environmental temperature, salinity, oxygen, pH, alkalinity, chlorophyll-a (Chl), copepod adult size, egg production (EP), and egg size and growth were assessed through 28 random oceanographic surveys. Agglomerative clustering and multidimensional scaling identified three main di-similitude nodes within temporal variability of abiotic and biotic variables: A) “upwelling”, B) “non-upwelling”, and C) “warm-acid” conditions. Nodes A and B represented typical features within the upwelling phenology, characterized by the transition from low temperature, oxygen, pH and Chl during upwelling to higher levels during non-upwelling conditions. However, well-oxygenated, saline and “warm-acid” node C seemed to be atypical for local climatology, suggesting the occurrence of a low frequency oceanographic perturbation. Multivariate (LDA and ANCOVA) analyses revealed upwelling through temperature, oxygen and pH were the main factors affecting variations in adult size and EP, and highlighted growth rates were significantly lower under node C. Likely buffering upwelling pH-reductions, phytoplankton biomass maintained copepod reproduction despite prevailing low temperature, oxygen and pH levels in the upwelling setting. Helping to better explain why this species is among the most recurrent ones in these variable yet productive upwelling areas, current findings also provide opportune cues on plankton responses under warm-acid conditions, which are expected to occur in productive EBUS as a consequence of climate perturbations.

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Section: Discussionmentioning

confidence: 99%

Upwelling modulation of functional traits of a dominant planktonic grazer during “warm-acid” El Niño 2015 in a year-round upwelling area of Humboldt Current

et al. 2019

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“…From studies that have focused on the effects of hypoxia on zooplankton, several themes have developed in the literature, some with more evidential support than others. There is clear evidence of direct effects of hypoxia on reproduction and survival of zooplankton when oxygen levels decline below critical, species-specific thresholds, e.g., [2][3][4][5][6][7]. Indirect effects of hypoxia have also been demonstrated, primarily acting through altered distributions which can increase encounter rates among predators and prey when both avoid hypoxic conditions [8][9][10], or decrease encounters when the hypoxia is used 2 of 16 as a predation refuge [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Zooplankton Community Response to Seasonal Hypoxia: A Test of Three Hypotheses

2020

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Several hypotheses of how zooplankton communities respond to coastal hypoxia have been put forward in the literature over the past few decades. We explored three of those that are focused on how zooplankton composition or biomass is affected by seasonal hypoxia using data collected over two summers in Hood Canal, a seasonally-hypoxic sub-basin of Puget Sound, Washington. We conducted hydrographic profiles and zooplankton net tows at four stations, from a region in the south that annually experiences moderate hypoxia to a region in the north where oxygen remains above hypoxic levels. The specific hypotheses tested were that low oxygen leads to: (1) increased dominance of gelatinous relative to crustacean zooplankton, (2) increased dominance of cyclopoid copepods relative to calanoid copepods, and (3) overall decreased zooplankton abundance and biomass at hypoxic sites compared to where oxygen levels are high. Additionally, we examined whether the temporal stability of community structure was decreased by hypoxia. We found evidence of a shift toward more gelatinous zooplankton and lower total zooplankton abundance and biomass at hypoxic sites, but no clear increase in the dominance of cyclopoid relative to calanoid copepods. We also found the lowest variance in community structure at the most hypoxic site, in contrast to our prediction. Hypoxia can fundamentally alter marine ecosystems, but the impacts differ among systems.

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“…This implies minimizing speciation-related changes due to in situ anaerobic–aerobic transformations. Also, previous O 2 deprivation in the field may create bias for germination/growth (chemical cues) at the start of the bioassay: crustaceans are sensitive to O 2 deprivation; , low O 2 induces dormancy (HOEC = 5.5 mg O 2 /L) . Taking 44 ± 4 mg/L and 0.21 as solubility ( T ≈ 20 °C) and partial pressure, respectively, this amounts to 60 ± 5% O 2 .…”

Section: Methodsmentioning

confidence: 99%

Bioconcentration of Organotin Cations during Molting Inhibits Heterocypris incongruens Growth

Nolte

Cooman

Vink

et al. 2020

Environ. Sci. Technol.

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The densely populated North Sea region encompasses catchments of rivers such as Scheldt and Meuse. Herein, agricultural, industrial, and household chemicals are emitted, transported by water, and deposited in sediments, posing ecological risks. Though sediment monitoring is often costly and time-intensive, modeling its toxicity to biota has received little attention. Due to high complexity of interacting variables that induce overall toxicity, monitoring data only sporadically validates current models. Via a range of concepts, we related bio-physicochemical constituents of sediment in Flanders to results from toxicity bioassays performed on the ostracod Heterocypris incongruens . Depending on the water body, we explain up to 90% of the variance in H. incongruens growth. Though variable across Flanders’ main water bodies, organotin cations and ammonia dominate the observed toxicity according to toxic unit (TU) assessments. Approximately 10% relates to testing conditions/setups, species variabilities, incoherently documented pollutant concentrations, and/or bio-physicochemical sediment properties. We elucidated the influence of organotin cations and ammonia relative to other metal(oxides) and biocides. Surprisingly, the tributylin cation appeared ∼1000 times more toxic to H. incongruens as compared to “single-substance” bioassays for similar species. We inferred indirect mixture effects between organotin, ammonia, and phosphate. Via chemical speciation calculations, we observed strong physicochemical and biological interactions between phosphate and organotin cations. These interactions enhance bioconcentration and explain the elevated toxicity of organotin cations. Our study aids water managers and policy makers to interpret monitoring data on a mechanistic basis. As sampled sediments differ, future modeling requires more emphasis on characterizing and parametrizing the interactions between bioassay constituents. We envision that this will aid in bridging the gap between testing in the laboratory and field observations.

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Egg production and hatching success of Calanus chilensis and Acartia tonsa in the northern Chile upwelling zone (23°S), Humboldt Current System

Cited by 18 publications

References 71 publications

Upwelling modulation of functional traits of a dominant planktonic grazer during “warm-acid” El Niño 2015 in a year-round upwelling area of Humboldt Current

Upwelling modulation of functional traits of a dominant planktonic grazer during “warm-acid” El Niño 2015 in a year-round upwelling area of Humboldt Current

Zooplankton Community Response to Seasonal Hypoxia: A Test of Three Hypotheses

Bioconcentration of Organotin Cations during Molting Inhibits Heterocypris incongruens Growth

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