Zooplankton Community Structure in Hardwater Hypertrophic Lakes of Alberta

1993 ◽  
Vol 27 (7-8) ◽  
pp. 353-361 ◽  
Author(s):  
B. Pinel-Alloul

Excessive concentrations of phosphorus are a common feature of hardwater eutrophic lakes in western Canada. Preliminary experimental lime treatment showed that this approach had a great potential to reduce phosphorus content and algal biomass. Therefore, two pairs of experimental and reference lakes were selected for a whole lake lime treatment and monitored for a full year prior to manipulation. This study presents the composition and size structure of the Zooplankton community of the lakes before treatment in order to assess the natural summer and inter-lake variations. Before lime treatment, seasonal means of total Zooplankton abundance and biomass ranged from 17 ± 8 to 127 ± 84 ind. L−1 and from 4 ± 2 to 138 ± 236 mg m−3, respectively. The two experimental lakes (Halftnoon and Lofty) were the richest in Zooplankton while the references lakes (Crooked and Jenkins) were the poorest. A total of 30 Zooplankton species (17 rotifers, 2 calanoids, 4 cyclopoids and 7 cladocerans) were recorded as well as 3 chaoborid species. The composition and size structure of Zooplankton varied between lakes and dates. Rotifers accounted for the majority of Zooplankton abundances (59-91%) while Cladocera (78-99%) or Copepoda (74%) in Crooked lake formed most of the Zooplankton biomass. Summer variations of the Zooplankton groups were described along with changes in size spectra. The temporal variation and the inter-lake differences in Zooplankton structure were discussed in relation to trophy, fish and invertebrate predation, and cyanophyte interactions.

1983 ◽  
Vol 40 (10) ◽  
pp. 1813-1819 ◽  
Author(s):  
J. S. Bays ◽  
T. L. Crisman

Zooplankton, including ciliated protozoans, were collected from 39 Florida lakes of widely ranging trophic state. Annual mean biomass values for different zooplankton groups were regressed against Carlson's Trophic State Index based on annual mean chlorophyll a concentration. Whereas total zooplankton biomass yielded a significant regression with increasing trophic state, microzooplankton (ciliates, rotifers, and nauplii) accounted for more of the relationship than macrozooplankton (cladocera, calanoids, and cyclopoids). Within the microzooplankton, the regression improved with decreasing body size. Macrozooplankton biomass exhibited a weak statistical relationship with lake trophic state, but the different component groups were variable in their response. The dominance within the zooplankton community shifts from macrozooplankton to microzooplankton with increasing trophic state, and the microzooplankton can constitute between 50 and 90% of the total zooplankton biomass in eutrophic lakes. Changes in zooplanktivore community structure with increasing trophic state show that whereas total fish biomass increases, dominance shifts from visually oriented predators, such as bass and bluegill, to pump filter-feeding planktivores, such as gizzard shad (Dorosoma cepedianum). While Florida zooplankton communities are similar in size structure to tropical communities, no statistically significant differences were found between empirical equations of crustacean zooplankton biomass and trophic state determined from temperate and Florida data bases.


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.


2015 ◽  
Vol 12 (3) ◽  
pp. 2381-2427 ◽  
Author(s):  
F. Carlotti ◽  
M.-P. Jouandet ◽  
A. Nowaczyk ◽  
M. Harmelin-Vivien ◽  
D. Lefèvre ◽  
...  

Abstract. This study presents results on the zooplankton response to the early phase of the northeastern Kerguelen bloom during the KEOPS2 survey (15 October–20 November 2011). The campaign combined a large coverage of the eastern part of the shelf and the adjacent oceanic regions with 2 quasi-perpendicular transects oriented south to north (between 49°08' and 46°50' S) and west to east (between 69°50' and 74°60' E) aiming to document the spatial extension of the bloom and its coastal-off shore gradient, and a pseudo-lagrangian survey located in a complex recirculation zone in a stationary meander of the Polar front nearly centered at the crossing of the 2 initial transects. In addition, 8 stations were performed for 24 h observations, distributed in key areas and some of them common with the KEOPS1 cruise (January–February 2005). The mesozooplankton biomass stocks observed at the beginning of the KEOPS2 cruise were around 2 g C m−2 both above the plateau and in oceanic waters. Zooplankton biomasses in oceanic waters were maintained in average below 2 g C m−2 over the study period, except for one station in the Polar Front Zone (FL), whereas zooplankton biomasses were around 4 g C m−2 on the plateau at the end of the cruise. Taxonomic composition and stable isotope ratios of size-fractionated zooplankton indicated the strong domination of herbivores. The most remarkable feature during the sampling period was the stronger increase in the integrated 0–250 m abundances in the oceanic waters (25 × 103 to 160 × 103 ind m−2) than on the plateau (25 × 103 to 90 × 103 ind m−2). The size structure and taxonomic distributions revealed a cumulative contribution of various larval stages of dominant copepods and euphausiids particularly in the oceanic waters, with clearly identifiable stages of progress during the Lagrangian survey. These different results during KEOPS2 suggested that the zooplankton community was able to respond to the growing phytoplankton blooms earlier on the plateau than in the oceanic waters. The reproduction and early stage development of dominant species were sustained by mesoscale-related initial ephemeral blooms in oceanic waters but individual growth was still food-limited and zooplankton biomass stagnated. On the contrary, zooplankton abundances and biomasses on the shelf were both in a growing phase, with slightly different rates, due to sub-optimal conditions of growth and reproduction conditions. Combined with the KEOPS1, the present results deliver a consistent understanding of the spring changes in zooplankton abundance and biomass in the Kerguelen area.


1983 ◽  
Vol 40 (11) ◽  
pp. 1912-1924 ◽  
Author(s):  
J. Anthony Koslow

A simulation model was used to examine whether predatory interactions may regulate the size structure of marine zooplankton communities, as observed in many freshwater systems. Results of the model were consistent with the freshwater studies, such that large increases or decreases in planktivorous fish led to the dominance of small or large zooplankters, respectively. However, model predictions were not consistent with the recent decline in the northeastern Atlantic of most major elements of the pelagic zooplankton community along with North Sea herring and mackerel stocks. The overall decline of the pelagic community throughout this region indicates that zooplankton abundance may be regulated by physical forcing, and that these populations may be food- rather than predator-limited. Realistic ecological simulations of marine pelagic systems may require more complex two-layer models allowing for the effects of vertical migration, and with day–night differences in food availability and selectivity.


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>


2013 ◽  
Vol 14 (3) ◽  
pp. 32 ◽  
Author(s):  
E. CHALKIA ◽  
G. KEHAYIAS

A one year investigation of the zooplankton community composition and dynamics in Lake Οzeros (western Greece) revealed 25 invertebrate species (16 rotifers, three copepods, five cladocerans and one mollusc larva). The mean zooplankton abundance fluctuated between 59.4 to 818 ind l-1, having maximum values in spring. The species composition and seasonal variation do not differentiate Lake Ozeros from the nearby lakes. The presence of the dominant calanoid copepod Eudiaptomus drieschi and some of the rotifer species recorded are characteristics of either oligo- or eutrophic lakes. According to the trophic state index (TSI) Lake Ozeros is a meso-eutrophic ecosystem, in which the eutrophic character was possibly the result of the high charge with phosphorus (being raised by 28.9 % in comparison to previous decades), which came into the lake via the surrounding agricultural cultivations and mainly the pig-raising activities. In contrast, the concentrations of ΝΟ3, ΝΟ2 and NH4 have considerably decreased possibly due to the termination of the tobacco cultivations around the lake during the last years. The novel information on the abiotic and especially the biotic elements of Lake Ozeros provided by the present study can contribute to the effective management of this aquatic ecosystem in the future.


1989 ◽  
Vol 46 (5) ◽  
pp. 810-817 ◽  
Author(s):  
Mark R. S. Johannes ◽  
Donald J. McQueen ◽  
Tom J. Stewart ◽  
John R. Post

A winterkill at Lake St. George, Ontario eliminated most of the piscivorous fish and some of the planktivores and also influenced zooplankton community structure. This disturbance and the subsequent recovery of the populations provided the opportunity to evaluate potential impacts of food and predators on the population structure and abundance of the dominant planktivore; the golden shiner (Notemigonus crysoleucas). interpretation of the 8-yr data set suggested that there was a positive relationship between adult golden shiner condition and zooplankton abundance, but that this did not translate into a significant stock–recruitment relationship between female numbers and young-of-the-year (YOY) recruitment. Also, there was no significant relationship between golden shiner survival and zooplankton abundance. However, there were significant negative correlations between YOY and adult golden shiner survival estimates and predator abundances. We conclude that at Lake St. George, golden shiner recruitment and population density is strongly influenced by predator density and is not influenced by food abundance.


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.


2015 ◽  
Vol 12 (14) ◽  
pp. 4543-4563 ◽  
Author(s):  
F. Carlotti ◽  
M.-P. Jouandet ◽  
A. Nowaczyk ◽  
M. Harmelin-Vivien ◽  
D. Lefèvre ◽  
...  

Abstract. This paper presents results on the spatial and temporal distribution patterns of mesozooplankton in the naturally fertilized region to the east of the Kerguelen Islands (Southern Ocean) visited at early bloom stage during the KEOPS2 survey (15 October to 20 November 2011). The aim of this study was to compare the zooplankton response in contrasted environments localized over the Kerguelen Plateau in waters of the east shelf and shelf edge and in productive oceanic deep waters characterized by conditions of complex circulation and rapidly changing phytoplankton biomass. The mesozooplankton community responded to the spring bloom earlier on the plateau than in the oceanic waters, where complex mesoscale circulation stimulated initial more or less ephemeral blooms before a broader bloom extension. Taxonomic compositions showed a high degree of similarity across the whole region, and the populations initially responded to spring bloom with a large production of larval forms increasing abundances, without biomass changes. Taxonomic composition and stable isotope ratios of size-fractionated zooplankton indicated the strong domination of herbivores, and the total zooplankton biomass values over the survey presented a significant correlation with the integrated chlorophyll concentrations in the mixed layer. The biomass stocks observed at the beginning of the KEOPS2 cruise were around 1.7 g C m−2 above the plateau and 1.2 g C m−2 in oceanic waters. Zooplankton biomass in oceanic waters remained on average below 2 g C m−2 over the study period, except for one station in the Polar Front zone (F-L), whereas zooplankton biomasses were around 4 g C m−2 on the plateau at the end of the survey. The most remarkable feature during the sampling period was the stronger increase in abundance in the oceanic waters (25 × 103 to 160 × 103 ind m−2) than on the plateau (25 × 103 to 90 × 103 ind m−2). The size structure and taxonomic distribution patterns revealed a cumulative contribution of various larval stages of dominant copepods and euphausiids particularly in the oceanic waters, with clearly identifiable stages of progress during a Lagrangian time series survey. The reproduction and early stage development of dominant species were sustained by mesoscale-related initial ephemeral blooms in oceanic waters, but growth was still food-limited and zooplankton biomass stagnated. In contrast, zooplankton abundance and biomass on the shelf were both in a growing phase, at slightly different rates, due to growth under sub-optimal conditions. Combined with our observations during the KEOPS1 survey (January–February 2005), the present results deliver a consistent understanding of patterns in mesozooplankton abundance and biomass from early spring to summer in the poorly documented oceanic region east of the Kerguelen Islands.


2019 ◽  
Vol 76 (Supplement_1) ◽  
pp. i10-i23
Author(s):  
Irina P Prokopchuk ◽  
Alexander G Trofimov

Abstract Our research focused on the analysis of interannual variability of zooplankton in the Kola Section (the Barents Sea) in the period of current warming in the Arctic basing on previously unpublished data. The zooplankton community was investigated based on the analysis of 240 plankton samples, collected in late May–early June 2009–2017. A total of 74 zooplankton taxa of nine phyla were identified in the plankton samples, but copepods were the most diverse and numerous taxonomic group. The biodiversity index varied considerably from year to year, but a stable tendency for the index to increase since the beginning of the period studied was observed. Copepods dominated in terms of abundance and biomass, comprising on average 73–96% of the total zooplankton abundance and 81–96% of the total zooplankton biomass. Calanus finmarchicus was the main zooplankton species utterly dominated by abundance and biomass (on average 92 and 97% respectively). Considerable differences in zooplankton abundance and biomass at different stations of the section were observed. Although the investigations were carried out during a warming period, interannual differences in zooplankton abundance and biomass were observed. Zooplankton biomasses were higher in the years with higher temperatures and stronger water inflow.


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