The Lake Baikal Seal: Already Endangered

Nerpa Populations in Decline
At the apex of this incredibly rich bio-system there stands one of the smallest of the world's seals, the so-called nerpa (a.k.a., phoca sibirica). This is the only species of seals that lives exclusively in fresh water. It is also one of the most secretive and mysterious of marine mammals.

The most troubling mystery about the nerpa is that no one knows exactly just how many there are at Baikal. The earliest animal census, taken in the mid-fifties, gave us an estimate of twenty to twenty five thousand seals. This estimate was based on interviews of hunters and other local inhabitants, and therefore was probably quite inexact. Beginning in the sixties, some hardy groups of surveyors began to motorcycle out onto the lake every winter to perform random transect-counts on the seal. By counting the number of ice-dens in certain parts of the lake, they were able to extrapolate that as many as 35-40 thousand seals were then living at Baikal. Only in the 1970s did attempts at census-taking (supposedly) become more consistent and exact -- and, for some, more intriguing in the findings. Besides the fact that all the motorcyclist-surveyors still managed to survive their sub-zero winter trips out onto the lake, the most surprising result of these counts was that the number of nerpa seemed to be growing every year! Even after the still-unexplained epidemics of 1987/88, the number of seals was placed at around 68,000.

Not surprisingly, however, was that this perceived increase in numbers enabled the government to raise the legal cull-rate on nerpa yearlings every year. Originally, some 2,200 were allowed to be taken annually. With the new inflated population figures, the legally sanctioned hunts grew to take five to six thousand annually. Even to this day, the hunting-collectives around Baikal "harvest" at least 5,000 nerpa a year. In the last decade or so, the accuracy of these counts and the wisdom of the legal culls has been called into question, especially by many leading environmental advocates. One group in particular, the Baikal Ecological Wave, has begun to call for more probing assessments of the status of the seal and its habitat.

Their concerns are many. First, even if the recent counts were in fact true, a legal cull rate of nearly 10% (especially of an animal that occupies the top ranks of the food chain) is considered inordinately high by most population biologists. Moreover, the 5-6 thousand that are taken every year does not consider the unmeasured number of seals that are shot but escape under the ice to die uncounted. (Oddly enough, one scientific study recently found that the most prevalent toxic substance detected in many seals was lead -- a fact which probably can be explained by all the seals that were shot with lead bullets and then survived to be tested!) There were other factors that alarmed the Baikal Wave and colleague activists at Baikal. In recent years, the pressure to poach the seals and sell them on the open market has increased with the new economic difficulties. And, of course, nobody knows exactly how many seals are poached every year. What is more, since there has been no successful census after 1992, there is no way of knowing about the most recent impacts on seal populations.

Added to this is the fact that, even before 1992, the number of seals in southern Baikal had been noticed to drop quite markedly. There have been several possible explanations for this decrease: the increasing dioxin and other pollution in the southern part of the lake; the loss of secure habitat (so near the urban populations of the south); and even global warming has been mentioned as a possible culprit (as the weather warms in Siberia, the southern half of the lake freezes later and thaws earlier, thus limiting the pupping season for nerpa).

Presented with all these warning signals, the Baikal Wave decided to embark upon a research, education, and lobbying program on behalf of the nerpa and of Lake Baikal itself. Using their own copious resources, as well as international funding from ISAR and Baikal Watch, the Wave set out to find the truth about three important issues -- just how bad were the effects: of pollution, of poaching and hunting, and of habitat destruction around Baikal?

The Baikal Wave has managed to collect vast amounts of information on the seal and its habitat, and created convincing documentation for a far-reaching public-education and lobbying program. Employing a team of local and international scientists, as well as cooperating with the local Baikal parks and nature reserves, the Wave has produced a number of written and videographic materials for use in the media and in local schools. In the long run, this program portends to be an important tool for influencing policy-makers. It is hoped that the latter will consider new protective measures for Baikal and its wild inhabitants given this new documentation. The question is, then: what have we all learned from this new documentation?

Toxics at Lake Baikal
Working with international seal specialists such as Dianne Kopec of Earth Island Institute's Marine Mammal Program, as well as with local scientists such as Evgenya Tarasova and Evgeny Petrov, the Wave discovered some rather alarming trends in the health of Lake Baikal and the Baikal seal.

First of all, many knew already that there was little genetic heterogeneity within the species phoca sibirica. Having diverged from the Arctic as a small group of seal nomads, the nerpa has spent the last 20 million years interbreeding at Baikal. This factor has made the nerpa ever-more susceptible to external impacts, including the introduction of foreign biological and inorganic agents.

Although it has been extremely difficult to prove incontrovertibly that pollution has in fact weakened the seal, many leading scientists are convinced that this has been the case. The most eminent of these is Grigory Galazii, former director of the Baikal Limnological Institute, and presently (and fortuitously) a leading representative serving on the Legislative Committee on Ecology for the Federal Duma. Dr. Galazii has said repeatedly that the recent epidemics were the direct result of too many contaminants in the nerpa's system, especially of the organochlorine variety. This situation has been compared to the recent Wadden Sea Epidemics, where seals with weakened immune suppression were unable to fight off a new virus introduced to their population.

There are yet other scientists looking into this matter, such as Dr. Olga Kazhova of Irkutsk University. She has studied waste discharges from the Baikalsk Pulp and Paper Plant at the southern end of the lake, and has gathered solid evidence of the effects of waste discharges from this plant and from industries along the Selenga (the main river that feeds into Baikal). Dr. Tarasova openly agrees that toxics may be threatening the seals more than previously was believed.

Most recently, Earth Island Institute's international seal specialist Dianne Kopec completed an exhaustive survey of contaminants and the nerpa at Baikal. The conclusions that she reached were quite alarming (Dianne's reports, as well as other scientific articles on the seal, may be obtained from Baikal Watch's offices in San Francisco). Dianne found that:

  • DDTs have entered Lake Baikal through aerial deposition, and have accumulated extensively in the sediment and biota. DDT residues in the nerpa are extremely elevated and pose a high risk to the population.
  • Toxic chlorinated pesticides such as hexachlorobenzene (HCH) and hexachlorocyclohexane (HCB) have appeared at elevated levels in areas around industrial discharges, such as in the Selenga River delta and in the lake sediment near Sludyanka.
  • PCBs have been measured in accumulated amounts in the lake sediment and in the water, especially in the area surrounding the Baikalsk Pulp and Paper Plant. Nerpa tend to assimilate toxic levels of PCBs, and, although it is not proven yet, it is likely that their health is compromised by this contaminant.
  • Alarmingly high levels of dioxins and furans were found in preliminary studies of residues in nerpa. (As in the case of PCBs, scientists believe that a more complete study is essential to defining the risks posed by this contaminant, particularly since the available information indicates that they exist at toxic levels in the nerpa.)

The recent findings summarized above indicate that the viability of Baikal's nerpa is threatened by toxic environmental contaminants. Yet, substantial gaps remain in our understanding of the overall impact of toxic pollution on Lake Baikal. Further research is needed in specific areas.

The chemical composition and concentration of environmental contaminants discharged into the lake must be defined for specific industrial and municipal sources of pollution. While this information is essential to refine regulatory policies designed to protect the environmental health of Lake Baikal, it is important that the absence of this information not be used as an excuse for inaction.

Available evidence that toxic levels of PCBs, DDTs, and certain other chlorinated pesticides are present in the nerpa warrants immediate action. Given the tremendous environmental loss which may occur if no efforts are made to halt the discharge of these contaminants, we must simultaneously undertake regulatory reform to reduce their discharge into Baikal while research further defines the source, accumulations and effects of these toxic pollutants.

At the same time, a more extensive and accurate count of the seal itself must be completed soon. And the results of all these studies must be used more consistently by local policy-makers as they determine if the legal culling should continue, and as they decide the fate of the Baikalsk Pulp and Paper Plant and other industries around the lake.

At this point, the important decisions that affect the nerpa are being made without considering key scientific evidence. It is up to such groups as the Baikal Wave to educate the people and their official representatives, to lobby for a legitimate count of the seal, to make sure that hunting is adequately monitored if not stopped, and to fight on, until the very rights of Lake Baikal and its nerpa denizens are protected for all time.

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