scholarly journals Western Pacific Zooplankton Community along Latitudinal and Equatorial Transects in Autumn 2017 (Northern Hemisphere)

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 58
Author(s):  
Yi Long ◽  
Md Abu Noman ◽  
Dawei Chen ◽  
Shihao Wang ◽  
Hao Yu ◽  
...  

During the autumn of 2017, a study was conducted to assess the zooplankton community composition in three sections (two latitudinal, going from Japan to the equator, and one longitudinal on the equator) of the Western Pacific Ocean. A total of 384 species of zooplankton adults and 21 groups of zooplankton larvae were identified, with copepods being the predominant taxon. The common dominant species across the three sections were Acrocalanus gibber, Canthocalanus pauper, Oithona similis, Paracalanus aculeatus, and Oncaea venusta. Zooplankton abundance was the highest in the equator section, with a mean abundance of 258.94 ± 52.57 ind./m3. Comparatively, a low abundance was recovered from the Subtropical Countercurrent (STCC) region, while the highest abundance holding stations were located in the eastern equatorial and North Equatorial Countercurrent (NECC) regions. Pearson’s correlation, canonical correspondence analysis, and other methods were used to analyze the relationship between environmental factors and zooplankton. We found that the Shannon–Wiener diversity index and Pielou’s uniformity index were significantly correlated (p < 0.05) with concentrations of nitrite and chlorophyll a. The distribution of zooplankton was also limited by nutrients, chlorophyll a, and dissolved oxygen. In addition, we reveal differences in the abundance of species in the equatorial and latitudinal seas. We found that not only temperature and nutrient salinity, but also ocean currents and the movement of water masses, influence the distribution of zooplankton communities in the Western Pacific.

Author(s):  
Seòna R Wells ◽  
Eileen Bresnan ◽  
Kathryn Cook ◽  
Dafne Eerkes-Medrano ◽  
Margarita Machairopoulou ◽  
...  

Abstract Major changes in North Atlantic zooplankton communities in recent decades have been linked to climate change but the roles of environmental drivers are often complex. High temporal resolution data is required to disentangle the natural seasonal drivers from additional sources of variability in highly heterogeneous marine systems. Here, physical and plankton abundance data spanning 2003–2017 from a weekly long-term monitoring site on the west coast of Scotland were used to investigate the cause of an increasing decline to approximately -80± 5% in annual average total zooplankton abundance from 2011 to 2017. Generalized additive mixed models (GAMMs), with an autoregressive correlation structure, were used to examine seasonal and inter-annual trends in zooplankton abundance and their relationship with environmental variables. Substantial declines were detected across all dominant taxa, with ∼ 30–70% of the declines in abundance explained by a concurrent negative trend in salinity, alongside the seasonal cycle, with the additional significance of food availability found for some taxa. Temperature was found to drive seasonal variation but not the long-term trends in the zooplankton community. The reduction in salinity had the largest effect on several important taxa. Salinity changes could partly be explained by locally higher freshwater run-off driven by precipitation as well as potential links to changes in offshore water masses. The results highlight that changes in salinity, caused by either freshwater input (expected from climate predictions) or fresher offshore water masses, may adversely impact coastal zooplankton communities and the predators that depend on them.


Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 644
Author(s):  
Nattaporn Plangklang ◽  
Sujeephon Athibai

Herbicide usage in rice fields over time may have a direct and indirect influence on the biodiversity of the fields. The impacts of herbicide usage on non-target organisms were assessed by examining the species richness and zooplankton density of two rice fields. One was 2.08 hectares in size and had been treated with pesticides during the sampling year (RF-PA). The second field, measuring 1.76 hectares, had received no pesticide treatment (RF-NPA). Every two weeks, zooplankton was quantitatively collected from ten sampling sites in each field. At each station, 20 L of measured water was filtered through a plankton net with a mesh size of 20 µm and preserved in 1% Lugol’s solution. The results revealed that RF-NPA and RF-PA had 112 and 88 species of zooplankton, respectively, with an abundance-based Jaccard index (Jabd) of 0.438. The total zooplankton density in RF-NPA was 24.4 ind./L, significantly higher than the 16.6 ind./L in RF-PA (p < 0.001). The Shannon-Wiener diversity index (H’) and evenness (J) were highest in RF-NPA at the second sampling (3.45 and 0.75, respectively). These results indicate that glyphosate application affects the diversity of species and density of zooplankton in rice fields.


Author(s):  
Johanna Pokorny

Invasive species are considered the greatest threat to aquatic ecosystem biodiversity. Bythotrephes longimanus, an exotic zooplankton species introduced to North America in the 1980s, is threatening the structure of indigenous aquatic ecosystems as it continues to invade inland Ontario lakes. As a predacious zooplankton species, B. longimanus has been shown to decrease zooplankton abundance, species richness and shift zooplankton community size structure in invaded lakes. However, much of the previous research concerning the predatory effects of B. longimanus has been on surveys of a small number of lakes or has been in controlled mesocosm or lab-based experiments. This study examines the effects of B. longimanus on the zooplankton community using size-structure characterizations (grouping individuals from the community based on size) as community measures for 311 lakes in the Muskoka Region, a highly invaded watershed in Southern Ontario. More specifically, the study explores the size-spectra of invaded versus uninvaded lakes, with reference to an array of environmental lake characteristics (water chemistry, lake morphometry,etc.), and the relevance of B. longimanus activity on the regional scale. By using such a large-scale survey we will be able to appreciate regional-scale effects, as well as encompass the multiple and more indirect trophic interactions that B. longimanus is likely having with the entire aquatic community. (Funding: NSERC & CAISN.)


2018 ◽  
Vol 66 (2) ◽  
Author(s):  
Johanna Medellín-Mora ◽  
Rubén Escribano ◽  
Wolfgang Schneider ◽  
Marco Correa-Ramírez ◽  
Nestor Campos

Zooplankton is an important component to understand oceanographic dynamics, they are considered good indicators of environmental variability, since most species are short-lived they can be tight coupling of climate and population dynamics, and some taxa are sensitive to variables such as temperature, quality and quantity of food, oxygenation and stratification. In the Colombian Caribbean two oceanographic cruises were carried out, in order to characterize and analyze the biodiversity of the continental margin, for the periods May-June 2008 and November-December 2009. The objective of this study was to determine which oceanographic variable was the most important in the distribution of zooplankton in the oceanic waters, and how the variables structure the community. In each cruise, zooplankton samples were obtained by vertical hauls with a 1 m2 diameter conical net (200 μm mesh size). The zooplankton community structure was studied by automated image analysis (ZooImage), which combined with abundance data, allowed to calculate the slope of size spectrum, and diversity indexes of taxa and sizes. The environmental variables included temperature, salinity, oxygen and chlorophyll a of the water column, and were used to calculate the stratification with the Brunt-Vaiisala frequency; this information was complemented by satellite images of temperature, surface chlorophyll, geostrophic currents and sea level, obtained from MODIS and AQUA products. The association between environmental variables and the zooplankton community structure was determined using Spearman’s correlation ranges with the Bioenv routine and a stepwise regression model, and Principal component analysis (PCA). Our results showed spatial and temporal patterns in the oceanographic conditions of the study area, such as upwelling in the Northeast region, strong stratification in the Southwest, and mesoscale activity. The abundance of zooplankton exhibited differences between the two climatic seasons and zones. Temporal differences were also evident in the size and diversity of taxa (ANOVA 2-way p <0.05). These changes were related to the moderate upwelling and the activity of mesoscale eddies. Cyclonic and anticyclonic eddies of variable size can either transport or retain zooplankton over cross-shelf and oceanic areas, thus modifying the taxonomic structure of the community. According to the Bioenv analysis, the main variables that explained the abundance and composition of zooplankton were sea level and chlorophyll a (Spearman correlation = 0.49). The stepwise regression showed that stratification, oxygen and chlorophyll a were the most important predictors of zooplankton abundance and size. Rev. Biol. Trop. 66(2): 688-708. Epub 2018 June 01. 


1999 ◽  
Vol 56 (10) ◽  
pp. 1865-1872 ◽  
Author(s):  
Eva Wahlström ◽  
Erika Westman

In order to study density-dependent effects of invertebrate planktivory, four different densities of Bythotrephes longimanus were inoculated into mesocosm enclosures with a mixed zooplankton community. Changes in size structure and abundance of zooplankton and phytoplankton communities were recorded over a period of 3 weeks. High densities of Bythotrephes were able to reduce total zooplankton abundance, which was mainly due to a decrease in the density of the relatively large species Holopedium gibberum. The density of the smaller species Bosmina longirostris was also reduced with increasing densities of Bythotrephes, whereas rotifer abundance remained largely unaffected. The mean size of Holopedium increased with increasing densities of Bythotrephes. Despite the decrease in total zooplankton biomass in high-Bythotrephes treatments, no effect of Bythotrephes density on primary producers was observed. Our experiment shows that predacious cladocerans may reduce macrozooplankton biomass, large as well as small species. Predation from invertebrate planktivores results in a zooplankton community consisting of larger individuals. Comparing our experimental densities with densities of Bythotrephes found in natural systems suggests that invertebrate planktivores may influence size structure and abundance of zooplankton communities even in lakes with planktivorous fish.


2012 ◽  
Vol 69 (7) ◽  
pp. 1205-1217 ◽  
Author(s):  
Kohei Matsuno ◽  
Atsushi Yamaguchi ◽  
Ichiro Imai

Abstract Matsuno, K., Yamaguchi, A., and Imai, I. 2012. Biomass size spectra of mesozooplankton in the Chukchi Sea during the summers of 1991/1992 and 2007/2008: an analysis using optical plankton counter data. – ICES Journal of Marine Science, 69: . An optical plankton counter was used to examine the regional characteristics of the zooplankton communities in the Chukchi Sea during the summers of 1991, 1992, 2007, and 2008. Zooplankton abundance and biomass ranged from 5000 to 1 170 000 ind. m−2 and 0.2 to 10.9 g dry mass m−2, respectively. Based on zooplankton biovolume in equivalent spherical diameter (ESD) in 48 bins, one every 0.1 mm between 0.25 and 5.0 mm, a Bray–Curtis cluster analysis classified zooplankton communities into four groups (A–D). No changes were observed in zooplankton communities south of the Lisburne Peninsula (group A) throughout the 4 years, but there were differences north of the Peninsula, with group B (normal, intermediate biomass) observed in 1991/1992, group D (low biomass) in 2007, and group C (predominance of barnacle larvae) in 2008. Analysis of the normalized biomass size spectra for the groups indicated that groups A and C were very productive, so the zooplankton community south of the Lisburne Peninsula was consistently highly productive, which may be because of the continuous inflow of Pacific Water rich in nutrients. Zooplankton communities north of the Lisburne Peninsula varied greatly from year to year, which may be related to interannual changes in sea-ice extent.


Author(s):  
My Ngoc Diem Tran ◽  
Anh Thi Tu Duong

These zooplankton samples and water samples were taken at 4 sites in the fish pond area (2 outside points in the river and 2 inside point in the fish pond). The results were recorded 76 zooplankton taxa which were belong to 28 genuses and 3 phylums (Protozoa, Rotifera and Arthropoda: Cladocera, Copepoda, Ostracoda). The Rotatoria phylum was dominated over 70% of species composition and 45% of individual density. The zooplankton communities in the outside were more diverse than those in the fish ponds. Besides, there was a significant difference between the individual density of the inside and outside ponds. The Shannon-Wiener diversity index showed that the water qualities were from lightly to moderately polluted at all points. Water of inside pond was polluted by organic materials, with the dominated by Brachionus genus. The Bray – Curtis similarity showed that the difference between zooplankton communities of inside and outside ponds was about 40%. Therefore, the fish pond water could affect natural water sources.


2016 ◽  
Vol 19 (4) ◽  
pp. 35-44
Author(s):  
Phuc Dinh Nguyen ◽  
My Ngoc Diem Tran

Species composition and characteristic of zooplankton communities in treated leachate of Dong Thanh landfills and in Rach Tra river (receiving the wastewater of Dong Thanh landfills) were surveyed monthly from 11/2012 to 04/2013. The results from those two areas were compared to find out the difference of the zooplankton communities. 122 species of 36 genus, 10 classes, 3 phylums and 6 types of larva were identified, of which Rotatoria acounted for 52 %. The result of Cluster analysis showed that there was a distinct difference between the zooplankton community intreated inside the landfills and Rach Tra river. The zooplankton community inside the landfills characterized by low quantity of species but high individual density. The main species composition was Rotatoria and Protozoa with good adaptation of organic and microbiological pollution of water. On the other hand, the zooplankton community in Rach Tra river characterized by communities in natural aquatic habitat with the relative balance of zooplankton groups, diversity index and dominance index were average levels.


2017 ◽  
Vol 17 (4) ◽  
pp. 207-214 ◽  
Author(s):  
Natalia Kuczyńska-Kippen ◽  
Piotr Klimaszyk ◽  
Ryszard Piotrowicz

Abstract The paper presents the results of an investigation of physical-chemical features of water as well as rotifer and crustacean abundance and diversity measures, relating to the taxonomic richness and species diversity index, in three lobelia lakes differing in trophic status and morphometric features. The main purpose of this study was to establish the diversity of zooplankton communities in the open water area of lobelia lakes, including extracting species common for each lake and also to find environmental predictors which are responsible for the development of zooplankton communities. Despite the fact that the three studied lakes are of the same origin, located in the same vicinity and have generally similar environmental factors, zooplankton community structure revealed a great variation in reference to species diversity (only ca. 20% of the species were common for all lakes) and particularly in inhabiting species. Obrowo Lake had the most diverse assemblages of both rotifers and crustaceans compared to Modre and Pomysko lakes. In the taxonomic structure species that are rare for the Polish fauna, such as e.g. Holopedium gibberum and Heterocope appendiculata, occurred. Even though the examined lobelia lakes are ecosystems that undergo varying human-induced impacts, they still remain taxonomically very variable aquatic ecosystems, containing rare species of very high ecological status. The observed symptoms of deterioration of water quality, reflected in the zooplankton biocoenotic features, showed that the best conditions were attributed to Obrowo Lake in comparison with the two remaining lakes – Modre and Pomysko. Total nitrogen and chlorophyll a concentration were decisive for the distribution of zooplankton species in Pomysko and Obrowo lakes, while in case of Modre lake water reactivity and conductivity were of higher impact.


Sign in / Sign up

Export Citation Format

Share Document