Trace Metal Contamination in Wetlands: Thol Bird Sanctuary Findings

Trace Metal Contamination in Wetlands: Thol Bird Sanctuary Findings

Last Updated: August 31, 2025

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Introduction

What hides beneath wetland mud can shape the health of birds, fish and people. Trace Metal Contamination in Wetlands accumulates in sediments and can enter food chains through benthic organisms.

The Ph.D. thesis by M. H. Bhadrecha (2018) at Thol Bird Sanctuary measured seasonal and spatial patterns of trace metals in sediments and water.

This post extracts verbatim thesis excerpts (with page numbers), explains findings in plain language, and lists clear monitoring and management actions.

Short paragraphs make this ready to paste into WordPress. The key points: sources, seasonal behavior, ecological risk, and practical fixes.

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Thesis excerpts (verbatim) — with page references

“Another serious concern for wetlands is the Heavy metal contamination attributed to waste dumping from industry and settlements in and around the wetlands, mining activities etc. Because of the their toxicity and ability to be incorporated into food chain due to their Bioaccumulation and Biomagnification potentials, these metals poses ecological risk as well as health risk on people growing and consuming food crops and vegetables grown with wetland waters and in the wetland.” (p. 20)

Plain English: Heavy metals from industry, settlements or runoff can stick in sediments, build up in small animals, and then magnify up the food chain — harming birds and people.

“Sediments are indicators of quality of water column over it. The nature of bottom and peripheral soil plays important function in the nutritional and ecological state of the pond.” (p. 19)

Plain English: Sediments record pollution. Testing sediment gives a reliable picture of metal contamination that water samples alone can miss.

“Spatio-Temporal variation in Trace Metals of Thol Wetland During Year 2016-2018” (Table 5.7; summary presented in Table 5.8). (pp. 87–88)

Plain English: The thesis presents location-wise and season-wise metal data (2016–2018). Use those tables to find which metals and which spots are worst.

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Key findings

The study detected trace metals in wetland matrices and documented **spatio-temporal variation**. Hotspots are linked to inflows, downstream industry and shoreline activities.

Monsoon pulses both deposit contaminated sediments and can dilute dissolved metal concentrations in water. Summer concentration and low water can increase exposure risks as metals become more bioavailable.

**Trace Metal Contamination in Wetlands** at Thol correlated with sediment organic content and benthic community shifts — areas with higher organic carbon often showed stronger metal associations and altered macroinvertebrate diversity.

When sediment-bound metals are present, **bioaccumulation** in benthic fauna (worms, snails, insect larvae) can lead to **biomagnification** in fish and birds that feed on them.

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Common trace metals of concern (what to watch)

• Lead (Pb) — neurotoxic, persistent in sediments.
• Cadmium (Cd) — accumulates in kidneys; toxic to birds and fish.
• Arsenic (As) — chronic human and wildlife hazard.
• Zinc (Zn) & Copper (Cu) — essential in small amounts but toxic at higher concentrations.
• Iron (Fe) — abundant but its redox dynamics affect metal mobility.

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Management & monitoring recommendations

1. Routine sediment testing: surface sediment cores (0–5 cm) seasonally (post-monsoon, winter, summer) at representative sites.
2. Targeted metal panels: measure Pb, Cd, As, Zn, Cu, Fe and organic carbon to understand binding and mobility.
3. Link chemistry with biology: run benthic macroinvertebrate surveys alongside sediment tests to detect bioaccumulation impacts.
4. Map hotspots: use thesis Table 5.7/5.8 locational data to prioritize sites for remediation or access controls.
5. Reduce inputs: control runoff, manage shoreline waste, and mitigate industry/oil-well risks to prevent further contamination.
6. Community advisory: avoid harvesting fish or shellfish from flagged hotspots until remediation and re-testing confirm safety.

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Short conclusion

Trace Metal Contamination in Wetlands is a hidden but serious risk that sediments reveal. Regular sediment monitoring, linked to biological surveys, is essential to protect wildlife, irrigation users and local communities.

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FAQs

Q: Why test sediments and not only water?
A: Sediments accumulate metals over time and reveal chronic contamination that water snapshots can miss.

Q: Do trace metals always move from sediment to organisms?
A: Not always — mobility depends on chemistry (redox, pH, organic matter). But under changing conditions (low oxygen, acidic), metals can become bioavailable.

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Author Bio

Researcher: Dr. M. H. Bhadrecha — Ph.D., Department of Zoology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara (2018). Research guided by Prof. P. C. Mankodi.

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Sources & Citations

Thesis Title: Ecosystem Assessment of Thol Bird Sanctuary with Special Reference to Benthic Macroinvertebrate Community

• Researcher: Dr. M. H. Bhadrecha
• Guide (Supervisor): Prof. P. C. Mankodi
• University: The Maharaja Sayajirao University of Baroda, Vadodara
• Year: 2018
• Excerpt Page Numbers Used: pp. 19–20, 87–88, 100–103 (see thesis tables and annexures for full trace-metal data)

For international context see the Ramsar guidance on wetland monitoring: Ramsar Convention.

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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.

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