Springtime Crustacean Zooplankton Abundance under Cold Water Conditions Is Determined Mainly by Temperature Regardless of Fish Predation

2014 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Minna Rahkola-Sorsa Blessing ◽  
Ari Voutilainen ◽  
Olli Urpanen ◽  
Hannu Huuskonen ◽  
Timo J. Marjomäki ◽  
...  
Keyword(s):  
Cold Water ◽  
Fish Predation ◽  
Crustacean Zooplankton ◽  
Zooplankton Abundance ◽  
Water Conditions

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

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Julie E. Keister ◽  
Amanda K. Winans ◽  
BethElLee Herrmann
Keyword(s):  
Community Structure ◽  
Puget Sound ◽  
Temporal Stability ◽  
Zooplankton Community ◽  
Community Response ◽  
Crustacean Zooplankton ◽  
Zooplankton Abundance ◽  
Calanoid Copepods ◽  
Low Oxygen ◽  
Seasonal Hypoxia

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.

scholarly journals Stable Isotope Analysis and Persistent Organic Pollutants in Crustacean Zooplankton: The Role of Size and Seasonality

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1490 ◽  
Author(s):  
Roberta Piscia ◽  
Michela Mazzoni ◽  
Roberta Bettinetti ◽  
Rossana Caroni ◽  
Davide Cicala ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Standing Stock ◽  
Fish Predation ◽  
Crustacean Zooplankton ◽  
Isotopic Signatures ◽  
Carbon And Nitrogen ◽  
Pollutant Concentrations ◽  
Stock Biomass

Zooplankton is crucial for the transfer of matter, energy, and pollutants through aquatic food webs. Primary and secondary consumers contribute to the abundance and standing stock biomass, which both vary seasonally. By means of taxa- and size-specific carbon and nitrogen stable isotope analysis, the path of pollutants through zooplankton is traced and seasonal changes are addressed, in an effort to understand pollutant dynamics in the pelagic food web. We analyzed zooplankton plurennial changes in concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and its relatives (DDTs) and in taxa-specific δ15N signatures in two size fractions, ≥450 µm and ≥850 µm, representative of the major part of zooplankton standing stock biomass and of the fraction to which fish predation is mainly directed, respectively. Our work is aimed at verifying: (1) A link between nitrogen isotopic signatures and pollutant concentrations; (2) the predominance of size versus seasonality for concentration of pollutants; and (3) the contribution of secondary versus primary consumers to carbon and nitrogen isotopic signatures. We found a prevalence of seasonality versus size in pollutant concentrations and isotopic signatures. The taxa-specific δ15N results correlated to pollutant concentrations, by means of taxa contribution to standing stock biomass and δ15N isotopic signatures. This is a step forward to understanding the taxa-specific role in pollutant transfer to planktivores and of zooplankton enrichment in PCBs and DDTs.

scholarly journals Impact of changing oceanographic conditions on species composition and abundance of zooplankton on the fishing grounds at Cape Navarin and their importance for the Russian pollock fishery in the Bering Sea

2017 ◽  
Vol 189 (2) ◽  
pp. 103-120
Author(s):  
Yury I. Zuenko ◽  
Eugene O. Basyuk
Keyword(s):  
Species Composition ◽  
Bering Sea ◽  
Cold Water ◽  
Zooplankton Abundance ◽  
Zooplankton Species ◽  
Shape Dependence ◽  
Spawning Areas ◽  
Species Specific ◽  
Bering Sea Shelf ◽  
The Bering Sea

Seasonal and interannual variability of zooplankton in the area at Cape Navarin are considered on the base of long-term surveys. This area is the main fishing grounds for Russian pollock fishery in the Bering Sea. Species composition of zooplankton changes cardinally during the feeding period: large-size copepods prevail in summer, but euphausiids, mainly the krill Thysanoessa inermis - in autumn. Year-to-year changes of the zooplankton abundance are species-specific and driven by different environmental factors. The water circulation is crucially important for such allochtonous species as krill by transporting them from the spawning areas. Advection either from the south, i.e. from the continental slope (till 2006), or from the east and west, i.e. from the shelf (in 2007-2014), was observed in the last two decades that corresponded to replacing of relatively warm oceanographic regime by relatively cold regime and could be traced by dynamics of the ice cover and the cold water pool area on the eastern Bering Sea shelf. The advection from the slope provides the krill transport to the area at Cape Navarin, but conditions of the cold regime limit the transport. From the other hand, the cold oceanographic regime is favorable for reproduction of many zooplankton species, including krill, because of higher primary productivity. As the result, the krill and some other mass zooplankton species have a bell-shape dependence of their abundance on water temperature: they have the maximal biomass in relatively warm years within the cold periods and in relatively cold years within the warm periods. In the years with severe winters, the pollock starts its back migration early, in August-September because of seasonal depletion of copepods and lack of krill, while the years with warm winters are also unfavorable for long feeding of pollock in the Navarin area because of low abundance of many zooplankton species. «Moderate» conditions are optimal for long feeding of pollock in this area, when the Russian fishery continues here longer, till November-December, with the annual landings > 500,000 t (as in 1996-1999, 2001, 2007-2008).

Nutrient excretion by crustacean zooplankton in the deep chlorophyll layer of Lake Superior

2015 ◽  
Vol 72 (3) ◽  
pp. 390-399 ◽  
Author(s):  
Samantha K. Oliver ◽  
Donn K. Branstrator ◽  
Thomas R. Hrabik ◽  
Stephanie J. Guildford ◽  
Robert E. Hecky
Keyword(s):  
Cold Water ◽  
Lake Superior ◽  
Soluble Reactive Phosphorus ◽  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Nutrient Excretion ◽  
Mysis Diluviana ◽  
Incubation Experiments ◽  
Limnocalanus Macrurus ◽  
Reactive Phosphorus

We hypothesized that the resident and migrating cold-water zooplankton in Lake Superior concentrate beneath the thermocline and elevate nutrient availability via mineralization in the deep chlorophyll layer (DCL). In August 2010 and 2011, diel vertical net tows and incubation experiments were conducted in the western arm of Lake Superior to measure zooplankton distribution and excretion of dissolved nutrients. Limnocalanus macrurus showed the strongest spatial overlap with the DCL, and the broader crustacean community excreted P at 0.145 μg·mg−1·h−1 and N at 0.617 μg·mg−1·h−1 as soluble reactive phosphorus (SRP) and ammonia, respectively. Mysis diluviana displayed strong diel vertical migration into the DCL and excreted P at 0.013 μg·mg−1·h−1 and N at 0.116 μg·mg−1·h−1 as SRP and ammonia, respectively. Based on primary productivity estimates, the zooplankton community has the potential to meet the daily phosphorus demand by phytoplankton in the DCL during late-season stratification. Our excretion estimates indicate a possible coupling between the cold-water zooplankton community and production in the DCL of Lake Superior.

First observations of crustacean zooplankton abundance in northern Patagonian rivers

Crustaceana ◽  
2015 ◽  
Vol 88 (5) ◽  
pp. 617-623 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Konrad Górski ◽  
Evelyn M. Habit ◽  
Aliro J. Manosalva
Keyword(s):  
Crustacean Zooplankton ◽  
Zooplankton Abundance

scholarly journals Calanoid copepods in central Chilean and Chilean Patagonian lakes (33-55°S, Chile), probable ecological key role in pelagic environments

Crustaceana ◽  
2017 ◽  
Vol 90 (14) ◽  
pp. 1793-1802
Author(s):  
Patricio R. De los Ríos Escalante ◽  
Fatima Kies
Keyword(s):  
Trophic Status ◽  
Zooplankton Community ◽  
Fish Predation ◽  
Crustacean Zooplankton ◽  
Calanoid Copepods ◽  
Number Of Species ◽  
Group Data ◽  
Patagonian Lakes ◽  
Freshwater Bodies ◽  
Ecological Importance

The Patagonian lakes (38-55°S) are characterized by their marked oligotrophy, low number of species of crustacean zooplankton, and a marked predominance of calanoid copepods. Within this context, we considered that a review about the ecology of the zooplankton in central and southern Chilean lakes would be useful, aiming to understand the ecological importance of this group. Data obtained from the literature for freshwater bodies in central and southern Chilean lakes were analysed. In addition, data from various bays with widely differing trophic status in Llanquihue Lake were examined. The results revealed the existence of originally pristine and oligotrophic sites, all with a low number of species and marked calanoid dominance. However, in northern Patagonia there are many lakes in which human intervention has caused an increase in phytoplankton activity, with a consequent replacement of calanoid copepods by daphniid cladocerans. Other important factors that could affect the zooplankton community would be fish predation, which is due to generate a decrease in large-bodied groups of zooplankton; and stress due to exposure to natural ultraviolet radiation. Ecological, biogeographical, and evolutionary topics are discussed within the framework described.

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