Table of Contents
Zooplankton diversity River Ravi — how floods shape microscopic life at Balloki
Last updated: August 29, 2025
Introduction (hook + why it matters)
Have you ever wondered how a seasonal flood can rearrange an entire invisible food web? Floodplains are ecological hotspots — and the tiny animals that drift in the water, the zooplankton, respond quickly to floods, nutrients, and water quality. This post unpacks a detailed PhD study of zooplankton diversity at River Ravi (Balloki Headworks), showing which groups dominate, how seasonal floods change richness and density, and which environmental factors matter most. We’ll use verbatim excerpts from the thesis (with exact page citations) and plain-language explanations so you get both the evidence and the practical meaning.
Thesis excerpt (verbatim) + analysis
“The present study was carried out on ‘Zooplankton assemblage in flood plains of River Ravi near Balloki Headworks, Pakistan.’ throughout the year 2012 i.e., from January 2012 to December 2012. The aim of the study was to estimate the temporal and spatial variations of zooplankton composition with respect to seasonal flooding.” (p. 1).
Plain English: this is a year-long, monthly-sampling study designed to capture seasonal variation — ideal for spotting monsoon/floodpulse effects on floodplain zooplankton.
Key finding — total species & group breakdown
“Zooplankton dynamics revealed a total of 157 zooplankton species belonging to 61 genera, 31 families, 14 orders and 8 classes. Highest number of species (82) was present in August while lowest (57) in January, with an overall mean of 70.5 species/month.” (p. 1).
Interpretation: species richness (S) rises with the flood season (peak in August) — a classic floodplain signature: connectivity and habitat variety increase, allowing more taxa to colonize.
Who dominates numerically?
“The population density data revealed that cumulative mean density ranged from 206.09 to 491.38 Ind./L, with an overall mean of 320.81 Ind./L. One year mean density data indicated a major peak of 491.38 Ind./L in June, with 70% and 21% contribution from rotifers and copepods, respectively.” (p. 1).
Plain English: numerically, rotifers dominate (≈70% in the density peak). Density peaked in June — late spring/early summer — before heavy monsoon dilution reduces densities, even as species richness increases during floods.
Group composition (verbatiM)
“Zooplankton population belonged to four different groups namely protozoan’s, rotifers, copepods and ostracods… Relative species contribution of different groups is protozoans (17.19%), rotifers (64.33%), copepods (17.19%) and ostracods (1.27%) respectively.” (p. 1).
Implication: Rotifers produce most of both species-count and numerical dominance — so when people search “rotifer abundance Balloki,” this study is a primary source.
Flood pulse effect (exact thesis phrasing)
“Species diversity showed positive, whereas species density showed negative relationship with the fluviometric level … The higher richness during maximum flood might be due to the fact that with flooding more habitats became available for colonization … High richness and diversity of zooplankton during high fluviometric level were also reported by [other studies].” (p. 127).
In plain terms: when the flood pulse raises water level, more species appear (higher richness) but individual counts per litre often decline (dilution effect). That yields greater diversity but lower density measurements.
Physicochemical correlations (verbatim)
“Zooplankton densities were positively correlated with **temperature, pH, conductivity, total dissolved solids, turbidity, total hardness and total alkalinities. On the other hand zooplankton density was negatively correlated with dissolved oxygen, visibility and chloride contents.” (p. 1).
What that means: warmer, more turbid, mineral-rich water (often summer or runoff-influenced) favors higher zooplankton counts — but higher DO and more transparent water often coincide with winter or less productive periods and lower zooplankton density. These relationships match regional findings about Balloki and similar floodplains.
Subheadings and practical takeaways
Flood pulse and Zooplankton diversity River Ravi
- Flooding increases habitat connectivity → more species (richness up in July–August).
- Flooding causes dilution → density per litre often drops even while richness rises. (See thesis pp. 1 & 127).
Dominant taxa and months to watch
- Rotifers dominate numerically (≈70% of density at peak). (p. 1).
- Protozoans peak in May, rotifers/total zooplankton peak in June, copepods/ostracods peak around July. (Results tables & figures).
Management & monitoring implications
- Monitor temperature, turbidity and conductivity as early predictors of density spikes.
- Sample across spatial zones (early littoral, limnetic) and depths (surface/mid/bottom) — the thesis shows meaningful horizontal & vertical differences.
Conclusion
This PhD study provides robust, month-by-month evidence that flood pulses at Balloki Headworks increase zooplankton species richness while altering density patterns, with rotifers as the primacy numerical group. For anyone studying zooplankton diversity River Ravi, the thesis is an essential, data-rich resource. Zooplankton diversity River Ravi remains tightly linked to flood pulse effects and water chemistry (temperature, turbidity, conductivity).
Disclaimer: Some sentences have been lightly edited for SEO and readability. For the full, original research, please refer to the complete thesis PDF linked in the section above.
Author bio (original researcher)
Altaf Hussain, PhD candidate (Session 2009–2013), Department of Zoology, Government College University (GCU) Lahore. Supervised by Dr. Abdul Qayyum Khan Sulehria, Associate Professor (Visiting Faculty), Department of Zoology, GC University, Lahore. The thesis was submitted in February 2015.
Source & Citations
Source & Citations
Thesis Title: ZOOPLANKTON ASSEMBLAGE IN FLOOD PLAINS OF RIVER RAVI NEAR BALLOKI HEADWORKS
Researcher: Altaf Hussain.
Guide (Supervisor): Dr. Abdul Qayyum Khan Sulehria.
University: Government College University (GCU), Lahore, Pakistan.
Year of Compilation: 2015 (submitted Feb 27, 2015).
Excerpt Page Numbers used: p. 1 (Abstract & summary), pp. 23–25 (Results & diversity), p. 61 (Table 4.12 density contribution), p. 127 (Discussion on flood pulse).
FAQs (short)
Q: When is zooplankton richness highest at Balloki?
A: Richness peaked in August (highest species count), while density peaked earlier (June) because of summer growth then monsoon dilution.
Q: Which group should monitoring programs focus on?
A: Rotifers — numerically dominant and responsive to environmental shifts; useful for rapid monitoring.
Q: Do floods always increase diversity?
A: Not always; this study found richness increased with flood level (connectivity), but other studies report different patterns depending on turbidity, timing, and local hydrology. Context matters.
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