Around 130 dead seals have washed up on the shores of Russia’s Lake Baikal this week, prompting an investigation by Siberian authorities. Scientists have identified exhaustion caused by hunger as the primary cause of the mass deaths, prompting further investigation into the mammals’ habitat and food chain.
The Moscow Times reported (1 November) that “The mass deaths follow recent reports that a tourist boom and pollution has led to the disappearance of local fish species and a growth of putrid algae…”
“After (Russian) President Vladimir Putin ordered government agencies to crack down on Lake Baikal polluters on Oct. 25, prosecutors have opened dozens of criminal cases connected to the violation of environmental protection rules”.
The same newspaper reported (2 November) that local residents have begun using the carcasses of the dead seals who washed up on the shores of Lake Baikal to feed their dogs.
Baikal is the largest freshwater lake in the world and has been a UNESCO World Heritage Site since 1996, with thousands of endemic species. The lake has suffered from a number of detrimental phenomena over recent years including depletion of fish stocks, death of endemic sponges and blooms of Spirogyra algae unnatural to the lake, caused by pollution. A boom in development associated with tourism has also been associated with environmental degradation. A 2017 UNESCO Conservation Report “noted with concern that the ecosystem of the lake is reported to be under significant stress with a decrease in fish stocks and algal blooms being some of the observed results”.
First reports of the mass seal deaths emerged last week from the Siberian republic of Buryatia where tourists reported about 30 dead animals on a sandy spit near the settlement of Novy Enkhaluk, with subsequent finds near the village of Marino, east of the river Khara-Murino.
Initially two main explanations of the mass death of animals were to be considered – a disease, or a negative change in the habitat.
Environmental ministry spokesman Nikolai Gudkov said “We took water samples to understand whether we can talk of water pollution as the reason”. Biopsies were also taken by scientists. The endemic Baikal seal (which is the smallest seal in the world) is reportedly not endangered, and Gudkov said the species’ population has actually increased in recent years, growing to around 130,000.
Veterinarians subsequently said that the deaths may have been caused by hunger, according to news agency TASS. “There’s the possibility that a lack of appetite in the animals may have led to (cardiac arrest),” Sergei Grokhotov, head of agriculture watchdog Rosselkhonadzor’s veterinary department, told the state-run news agency.
“They have in effect died from exhaustion,” Grokhotov said, pointing out that biopsies conducted on the corpses had not revealed any organ damage, adding that veterinarians will now inspect the seals' food chain to investigate possible causes of starvation.
President Putin previously expressed concern about the lake’s environment earlier this year, complaining to officials that "significant areas around Baikal have suffered extremely high pollution."
Speaking after a fishing expedition on the lake in August he said that Baikal "belongs to the entire planet”, and insisted that preserving it for future generations is "undoubtedly a government priority." Putin called for officials to pay "special attention" to clean up the aftermath of "irrational and often irresponsible economic activity" around the lake, citing the need to "drastically cut down the volume of untreated water being discharged into the lake."
In 2009 Putin reportedly inspected the bottom of Lake Baikal in a mini-submarine.
Researchers from Russia’s Limnological Institute warned in 2015 that water in some parts of the lake is unfit for consumption by humans or livestock. Water quality checks carried out by the Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor) in the Irkutsk region had found that some treatment facilities were not treating water to epidemiological standards before discharging it into the water body.
Environmentalists say extremely hot and dry summers and deforestation have contributed to the problems, and the Russian government has also become concerned about the effects of hydropower facilities on rivers that flow into the lake, particularly a series of hydropower plants to be built in neighboring Mongolia on the Selenge River, the largest tributary feeding the Siberian lake, as well as the Orkhon, Egyin-Gol, Tola, and Delgermuren rivers.
Baikal's water levels are critically low. Some Russian experts have said the lake has entered a natural shallow period; the Mongolian government has also made this argument, saying construction of reservoirs would make it possible to regulate outflows of water from the lake.
However, Scientists at Russian Academy of Sciences said a year ago that the declining water levels in the lake could be linked to climatic changes in Asia, which have brought less rainfall and higher air temperatures.