# The Periyar Fish Kill of May 2024 near Pathalam > On 20 and 21 May 2024, large numbers of fish died in the Periyar downstream of the Pathalam regulator-cum-bridge, near Eloor and Kalamassery, hitting cage-fish farmers and fishers as far as Kadamakkudy. The shutters had just been opened after a long closure. Official bodies did not agree on the cause: the pollution control board pointed to oxygen-starved water and sludge, while a fisheries university study found toxic gases and chemicals. This page sets out both, as of October 2026. - URL: https://ashrafgentspghostel.adserr.com/periyar-fish-kill-may-2024/ - Publisher: Ashraf Gents Hostel, Ashraf house, NAD Rd, signal, Kalamassery, Aluva, Kerala 683563, India (+91 90746 23855) - Published: 2026-10-08 · Updated: 2026-10-08 - Topic: History & archive - Cite as: Ashraf Gents Hostel. “The Periyar Fish Kill of May 2024 near Pathalam.” Published 8 October 2026. https://ashrafgentspghostel.adserr.com/periyar-fish-kill-may-2024/ ## Key facts - The fish kill happened on 20–21 May 2024 after the Irrigation Department opened three shutters of the Pathalam regulator-cum-bridge on 20 May, according to the Kerala University of Fisheries and Ocean Studies (KUFOS), as reported by Mongabay India. - The Kerala State Pollution Control Board's preliminary view was that fish died because dissolved oxygen fell when oxygen-depleted water and organic sludge from upstream flowed down suddenly; it measured 1.6 mg/litre at the Pathalam bund. - A KUFOS report found elevated hydrogen sulphide, worsened by ammonia, to be the primary cause, and reported heavy metals and toxic chemicals in water, sediment and fish (Mongabay India). - Fisheries Minister Saji Cherian announced ₹13.55 crore in compensation; as of July 2024 fishers told Mongabay India they had not received it. - The Kerala High Court ordered a committee on Periyar pollution on 10 June 2024; it filed an interim report on 3 July 2024, and the pollution board reported to the National Green Tribunal in November 2024. ## The place: Pathalam regulator The Pathalam regulator-cum-bridge crosses the Periyar between Kalamassery and Eloor. In the dry months its shutters are kept closed to hold back salt water moving up from the backwaters, and the river above it slows. Downstream lie Eloor's industrial belt, Kadamakkudy and the fishing grounds where many families keep fish in cages (see [Manjummel and Pathalam](https://ashrafgentspghostel.adserr.com/manjummel-and-pathalam-guide/) and [Eloor's history](https://ashrafgentspghostel.adserr.com/eloor-island-history/)). Fish deaths in this stretch were not new: Deccan Chronicle reported another in April 2018, and the river's pollution record is in our [Eloor pollution timeline](https://ashrafgentspghostel.adserr.com/eloor-pollution-timeline/). ## Timeline | Date | What happened | Source | |---|---|---| | 20 May 2024, 3.30 pm and 6 pm | Irrigation Department opens three shutters of the Pathalam regulator | KUFOS via Mongabay India | | 20–21 May 2024 | Large-scale fish kill downstream, from Pathalam and Eloor to Kadamakkudy and Vaduthala | Mongabay India | | May 2024 | KSPCB preliminary view: oxygen depletion from upstream water and sludge; 1.6 mg/l at the bund | KSPCB, as reported | | 10 June 2024 | Kerala High Court orders a committee to suggest steps against Periyar pollution | KSPCB report, India Environment Portal | | 3 July 2024 | Committee files interim report noting significant faecal contamination in monitoring data | KSPCB report, India Environment Portal | | 11 July 2024 | Mongabay India reports KUFOS findings and that compensation had not reached fishers | Mongabay India | | 19 November 2024 | KSPCB files a report on Periyar pollution before the National Green Tribunal | India Environment Portal | ## What happened in May 2024 According to the KUFOS report summarised by Mongabay India, the Irrigation Department opened one shutter of the Pathalam regulator at 3.30 pm on **20 May 2024** and two more at 6 pm. The department said it did so because water levels were rising with heavy rain and releases from the Bhoothathankettu barrage upstream. Within hours, fish began dying downstream, and by 21 May dead fish were reported from Pathalam and Eloor down to Kadamakkudy and Vaduthala. The losses fell on small producers. Mongabay quoted Subbayan T. R., a cage-fish farmer in Eloor, as saying about 60 families in his area had lost stock, and a Kadamakkudy fisherman, Jefin, estimating his own loss at ₹10 lakh. The KUFOS report described the deaths of 'hundreds of thousands of fish and other aquatic life forms'. We did not find an official total in tonnes, so we do not give one. ## The findings: three views ### Pollution Control Board The Kerala State Pollution Control Board (KSPCB) said its preliminary view was that the fish died because dissolved oxygen downstream fell sharply with the sudden, continuous flow of oxygen-depleted water from upstream and of organic sludge from the bund. Its chief environmental engineer gave a reading of 1.6 mg/litre at the Pathalam bund. The board also said the Irrigation Department had not informed it or other departments before opening the shutters. In its later report to the tribunal, it noted a trend of low oxygen in the lower river in summer. ### Fisheries university (KUFOS) KUFOS reached a different conclusion. Its field inspection and laboratory analysis, Mongabay reported, found elevated **hydrogen sulphide** to be the primary cause, made worse by ammonia, produced by organic matter that had built up in the stagnant water above the regulator, including household waste, drain run-off and effluents from markets and hotels. It also reported alarming levels of heavy metals and toxic chemicals in the water, sediment and fish. ### Fisheries scientists and residents An official at the Central Marine Fisheries Research Institute, speaking anonymously to Mongabay, said oxygen had fallen to about 1 mg/litre in places but that damage to the gills, kidneys and livers of dead fish pointed to chemical toxins as well. Residents, environmental groups and the Irrigation Department suspected industrial effluent from units near the river; the pollution board's early position did not support that, and we found no official finding naming a particular company. > The causes remain contested in the public record. This page reports what each body said; it does not decide between them. ## What followed The state government asked the Irrigation Department to draw up a standard operating procedure for opening the Pathalam shutters, and set up a coordination committee of the fisheries, irrigation, local self-government and pollution control departments. Fisheries Minister Saji Cherian announced **₹13.55 crore** in compensation; in July 2024 fishers told Mongabay it had not yet reached them. We did not find a later report confirming payment. The Kerala High Court, hearing matters on Periyar pollution, ordered on **10 June 2024** that a committee be formed to suggest steps to curb it. The committee's interim report of **3 July 2024**, drawing on national water-quality monitoring data for 2022–2024, said faecal contamination of the river was significant. The KSPCB filed a report before the National Green Tribunal dated **19 November 2024**. For the wider year, see [Kalamassery in 2024](https://ashrafgentspghostel.adserr.com/kalamassery-in-2024/). ## Why this history matters near the NAD signal The Periyar is Kalamassery's river, so what happens at Pathalam matters even a few kilometres inland at the NAD Road signal. Ashraf Gents Hostel, a men's hostel/PG on NAD Road, includes water in the rent according to its owner's site; ask about current arrangements on +91 90746 23855. More on the local water supply is in [drinking water in Kalamassery](https://ashrafgentspghostel.adserr.com/drinking-water-kalamassery/), and more records in the [Kalamassery history archive](https://ashrafgentspghostel.adserr.com/kalamassery-history-archive/). ## Frequently asked questions **When was the Periyar fish kill?** On 20–21 May 2024, after shutters of the Pathalam regulator-cum-bridge were opened on the afternoon and evening of 20 May. **What caused it?** Official bodies differed. The Pollution Control Board pointed to oxygen-depleted water and sludge released downstream; KUFOS found hydrogen sulphide and ammonia to be the main cause and reported heavy metals and toxic chemicals. **Was an industry blamed?** Residents and environmental groups suspected industrial effluent, but we found no official finding naming a particular company. **Was compensation paid?** The Fisheries Minister announced ₹13.55 crore. In July 2024 fishers said they had not received it; we found no later confirmation. **What did the High Court do?** On 10 June 2024 it ordered a committee to suggest ways to curb Periyar pollution; the committee filed an interim report on 3 July 2024. ## Sources - [Mongabay India: Massive fish kill in Periyar river attributed to industrial pollution (11 July 2024)](https://india.mongabay.com/2024/07/massive-fish-kill-in-periyar-river-attributed-to-industrial-pollution/) - [India Environment Portal: Report by the Kerala State Pollution Control Board regarding Periyar river pollution, 19/11/2024](https://indiaenvironmentportal.org.in/in-court/report-by-the-kerala-state-pollution-control-board-regarding-periyar-river-pollution-19112024) - [Deccan Chronicle: Periyar river sees fish kill again (April 2018)](https://deccanchronicle.com/amp/nation/in-other-news/050418/periyar-river-sees-fish-kill-again.html) - [Wikipedia: Eloor](https://en.wikipedia.org/wiki/Eloor) --- Facts about Ashraf Gents Hostel come from the hostel’s own profile, photos and Google Site; rates are indicative and confirmed on the call. 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