scholarly journals Spatial variability of zooplankton community structure in Colombian Caribbean waters during two seasons

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. 

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Arief Rachman ◽  
Elly Asniariati

<p>Banggai Sea is an interesting ecosystem due to mixing influences from Banda Sea in the west and Maluccas Sea in the east. Therefore, a unique zooplankton community structure and specific distribution pattern should be found in this area. This research was carried on using Baruna Jaya VIII research vessel and samples were collected in 14 sampling stations. Vertical towing using NORPAC plankton net (300 μm) was conducted to collect zooplankton samples. Result showed that inner Mesamat Bay had the lowest abundance of zooplankton, probably due to low water quality resulted from anthropogenic activity. Meanwhile the strait between Liang and Labobo Island had the highest zooplankton abundance in Banggai Sea. Calanoids was the dominant zooplankton taxa in the ecosystem and contributing 55.7% of total density of zooplankton community. The highest importance value made this taxa to be very important factor that regulates the lower trophic level organisms. Results also showed that zooplankton was distributed nearly uniform in eastern but aggregated to several stations in western Banggai Sea. Zooplankton abundance was higher in the central of Banggai Sea, compared to western and eastern area. According to Bray-Curtis clustering analysis the strait between Liang and Labobo Island has unique zooplankton community structure. This might happened due to mixing of water from two highly productive seas that influenced the Banggai Sea ecosystem. From this research we conclude that this strait probably was the zooplankton hot spot area which might also indicate that this area also a hot spot of fishes in the Banggai Sea.</p><p>Keywords: spatial distribution, zooplankton, community structure, hot spot, Banggai</p>


Elem Sci Anth ◽  
2015 ◽  
Vol 3 ◽  
Author(s):  
Stephanie E. Wilson ◽  
Rasmus Swalethorp ◽  
Sanne Kjellerup ◽  
Megan A. Wolverton ◽  
Hugh W. Ducklow ◽  
...  

Abstract The Amundsen Sea Polynya (ASP) has, on average, the highest productivity per unit area in Antarctic waters. To investigate community structure and the role that zooplankton may play in utilizing this productivity, animals were collected at six stations inside and outside the ASP using paired “day-night” tows with a 1 m2 MOCNESS. Stations were selected according to productivity based on satellite imagery, distance from the ice edge, and depth of the water column. Depths sampled were stratified from the surface to ∼ 50–100 m above the seafloor. Macrozooplankton were also collected at four stations located in different parts of the ASP using a 2 m2 Metro Net for krill surface trawls (0–120 m). The most abundant groups of zooplankton were copepods, ostracods, and euphausiids. Zooplankton biovolume (0.001 to 1.22 ml m-3) and abundance (0.21 to 97.5 individuals m-3) varied throughout all depth levels, with a midsurface maximum trend at ∼ 60–100 m. A segregation of increasing zooplankton trophic position with depth was observed in the MOCNESS tows. In general, zooplankton abundance was low above the mixed layer depth, a result attributed to a thick layer of the unpalatable colonial haptophyte, Phaeocystis antarctica. Abundances of the ice krill, Euphausia crystallarophias, however, were highest near the edge of the ice sheet within the ASP and larvae:adult ratios correlated with temperature above a depth of 60 m. Total zooplankton abundance correlated positively with chlorophyll a above 150 m, but negative correlations observed for biovolume vs. the proportion of P. antarctica in the phytoplankton estimated from pigment ratios (19’hexanoyloxyfucoxanthin:fucoxanthin) again pointed to avoidance of P. antarctica. Quantifying zooplankton community structure, abundance, and biovolume (biomass) in this highly productive polynya helps shed light on how carbon may be transferred to higher trophic levels and to depth in a region undergoing rapid warming.


2020 ◽  
Vol 32 (3) ◽  
pp. 168-179 ◽  
Author(s):  
V. Venkataramana ◽  
N. Anilkumar ◽  
K. Swadling ◽  
R.K. Mishra ◽  
S.C. Tripathy ◽  
...  

AbstractThe community composition of zooplankton with an emphasis on copepods was assessed in the frontal zones of the Indian sector of the Southern Ocean (SO) during summer 2013. Copepods were the dominant group in both the bongo net and multiple plankton sampler across the entire region. High zooplankton abundance was recorded along each transect in the Polar Front (PF). Community structure in this front was dominated by common taxa, including Ctenocalanus citer, Clausocalanus spp., Calanoides acutus, Calanus propinquus, Calanus australis and Rhincalanus gigas, which together accounted for > 62% of the total abundance. Calocalanus spp., Neocalanus tonsus and C. propinquus were indicator species in the Sub-Tropical Front (STF), Sub-Antarctic Front and PF, respectively. A strong contrast in population structure and biovolume was observed between then PF and the STF. The community structure of smaller copepods was associated with the high-temperature region, whereas communities of larger copepods were associated with the low-temperature region. Thus, it seems probable that physical and biological characteristics of the SO frontal regions are controlling the abundance and distribution of zooplankton community structure by restricting some species to the warmer stratified zones and some species to the well-mixed zone.


1992 ◽  
Vol 49 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Andrew M. Turner ◽  
Gary G. Mittelbach

We examined the effects of grazer community composition and fish on phytoplankton abundance by manipulating zooplankton community structure and the intensity of planktivory in a factorial experiment. Enclosures (1700-L bags) were treated with fish (present/absent) and two grazer communities (one a large-bodied community dominated by Daphnia and the other a small-bodied community dominated by Ceriodaphnia) in a 2 × 2 factorial design. We sampled zooplankton and algae every 4–8 d during the 5-wk experiment. Algal biovolume, chlorophyll a, total particulates, and light extinction were all significantly higher in the presence of fish. Further, the effect of fish on algal standing crop did not depend on which grazer assemblage was initially present. Fish enhanced algal standing crop to the same degree in both Daphnia and Ceriodaphnia treatments. We discuss these results in light of patterns reported in the literature, and the nature of size-structured interactions among fish, zooplankton, and algae.


1994 ◽  
Vol 51 (2) ◽  
pp. 401-407 ◽  
Author(s):  
Asit Mazumder

Data from experimental enclosures and natural and manipulated lakes were used to test whether the variable chlorophyll a (Chl) yields to total phosphorus (TP) can be explained by the variable contributions of dissolved (TDP) and zooplankton phosphorus (ZP; P > 200 μm) to TP. Results indicate that low Chl yields to TP in systems with abundant large Daphnia are closely related to greater contributions of TDP and ZP to TP. An opposite pattern is produced by systems lacking large Daphnia. These patterns seem to be consistent among mesoeutrophic to hypereutrophic systems; Chl yields to TP decline with increasing contributions of TDP to TP. In the large-Daphnia-dominated systems, both high grazing and reduced phosphate demand allow a greater sequestering of P into zooplankton and dissolved pools rather than in algae, which generate a lower observed Chl yields to TP. Conversely, lack of large Daphnia and low grazing rates allow proliferation of small algae, and an associated intense phosphate demand allows greater sequestering of P into small algae rather than into zooplankton and dissolved pools, and consequently, a higher Chl yield to TP is produced.


2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Arief Rachman ◽  
Elly Asniariati

Banggai Sea is an interesting ecosystem due to mixing influences from Banda Sea in the west and Maluccas Sea in the east. Therefore, a unique zooplankton community structure and specific distribution pattern should be found in this area. This research was carried on using Baruna Jaya VIII research vessel and samples were collected in 14 sampling stations. Vertical towing using NORPAC plankton net (300 μm) was conducted to collect zooplankton samples. Result showed that inner Mesamat Bay had the lowest abundance of zooplankton, probably due to low water quality resulted from anthropogenic activity. Meanwhile the strait between Liang and Labobo Island had the highest zooplankton abundance in Banggai Sea. Calanoids was the dominant zooplankton taxa in the ecosystem and contributing 55.7% of total density of zooplankton community. The highest importance value made this taxa to be very important factor that regulates the lower trophic level organisms. Results also showed that zooplankton was distributed nearly uniform in eastern but aggregated to several stations in western Banggai Sea. Zooplankton abundance was higher in the central of Banggai Sea, compared to western and eastern area. According to Bray-Curtis clustering analysis the strait between Liang and Labobo Island has unique zooplankton community structure. This might happened due to mixing of water from two highly productive seas that influenced the Banggai Sea ecosystem. From this research we conclude that this strait probably was the zooplankton hot spot area which might also indicate that this area also a hot spot of fishes in the Banggai Sea.Keywords: spatial distribution, zooplankton, community structure, hot spot, Banggai


2009 ◽  
Vol 69 (3) ◽  
pp. 819-835 ◽  
Author(s):  
R. Nadai ◽  
R. Henry

A river lateral lake (Coqueiral Lake marginal to Paranapanema River in its mouth zone into Jurumirim Reservoir, São Paulo, Brazil) presented fragmentation into four small isolated bodies of water during a prolonged drought period, disrupting the link with the river. The aim of this work was to compare the temporal modifications on zooplankton community structure (total abundance, species richness, and diversity) in the four water bodies. Zooplankton samplings and abiotic factor measurements were made in two periods - during isolation phase of the lake in relation to river and after re-establishment of hydrologic connectivity. A concentration effect on zooplankton abundance was recorded with drought progression, but without significant modifications in species richness and diversity. When the river inundation pulse occurred, a reduction in total zooplankton density was observed due to the dilution effect and a significant increase in species richness and diversity was recorded. Lateral water influx from the river to the lacustrine environment acts as a temporary disturbance factor on the zooplankton community structure. Zooplankton species composition presented some modifications between the two periods. Zooplankton organism drift in water from the river to the lake, removal of individuals from the aquatic macrophytes, and eclosion of resting eggs from sediment are probable factors that can increase zooplankton species richness immediately after lateral pulse inundation with water by the river.


2020 ◽  
Vol 193 (3) ◽  
pp. 213-225 ◽  
Author(s):  
Michael A. Figueroa-Sánchez ◽  
S. Nandini ◽  
S.S.S. Sarma

We studied the seasonal variation of rotifers, cladocerans and copepods in Lake Zumpango, Mexico City, from June 2010 to May 2011. Physical and chemical variables of the water were measured at three sites, while 50 L of water was filtered from these sites to study the zooplankton abundance, diversity and biomass. The water temperature ranged from 14 to 23 °C, and nitrate and phosphate concentrations from 0.2 to 1 and 4 to 14 mg L–1, respectively. Microcystis sp. Dolichospermum sp. and Planktothrix sp. were present throughout the year. Microcystin concentrations were between 0.06 to 11.7 μg L –1, but for six months the concentrations exceeded 1 μg L–1 (1.1 to 11.7 μg L –1), with the highest concentrations observed in August and October. We recorded 33 species of rotifers, including Brachionus angularis (1 to > 11000 ind. L–1) and Brachionus havanaensis (1 to 6683 ind. L –1), while the most abundant cladoceran was Moina micrura (about 10 ind. L–1). The species diversity ranged from 0.8 to 2.9 bits ind–1, but small (< 250 μm) zooplankton (rotifers and copepod nauplii) dominated the community.


1984 ◽  
Vol 41 (7) ◽  
pp. 1089-1096 ◽  
Author(s):  
Michael L. Pace

Simultaneous observations were made of total phosphorus (TP), chlorophyll a (Chl a), and zooplankton biomass and community structure at 12 sites in the Eastern Townships (ET) region of Quebec to determine if zooplankton parameters reduced residual variation in the TP–Chl a relationship. Similar data from three stations in Lake Memphremagog and the literature were also analyzed. Zooplankton biomass was not significant in explaining residual variation in the TP–Chl a relationship of any data set studied. The mean body size of cladocerans was also not a significant additional variable in a TP–Chl a model based on the seasonal mean values in the ET lakes, but cladoceran body size was a significant factor in 13 lakes of the Indian River district of New York. The difference between these results is attributed to the rarity of large daphnids in the ET lakes. An index of zooplankton community structure derived from the slope of log abundance–log weight regressions was significant in explaining residual variation in TP–Chl a relationships for the among- and within-lake data and improved the predictive capability of TP–Chl a models. Lakes with higher concentrations of macrozooplankton relative to microzooplankton have less Chl a per unit TP. These results extend the generality of the hypothesis that large zooplankton differentially reduce Chl a relative to TP. In the ET lakes the effect of zooplankton size structure, however, was weak and this suggests that manipulation of zooplankton community structure to manage algal biomass may be of limited value in many lakes.


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