I'm back! No need to say that you all missed me. I can sense it. I was actually in Pittsburgh, paying a visit to the boyfriend and exploring the city. Nice place. Lots of trees, lots of rivers. Very humid, but also lightning bugs.
The Baikal Seal (Pusa sibirica) is the only exclusively freshwater seal in the world. It can only be found in Lake Baikal of Siberia, and it's also one of the smallest seal species. It's possible that the ancestors of this species first made their way to Lake Baikal when a channel opened up from the Arctic Ocean, but no one knows for certain how the seals got there two million years ago - Lake Baikal is hundreds of miles inland.
Adult Baikal Seals only grow up to a little over 4 feet (1.5 meters) in total body length, and weigh an average of 154 pounds (70 kg). Sexual dimorphism among Baikal Seals is less extreme than in the larger species - males are larger than females, but not by a significant margin. They live solitary lives for most of the year, not close to other seals. They generally favor the northern part of the lake, where the winter ice lasts longer. The ice is more ideal for pupping season. Baikal Seals have recently been observed on the southern part of the lake, however, possibly as an attempt to avoid hunters.
Baikal Seals feed primarily on golomyanka, or oilfish. This, too, is a species that can only be found in Lake Baikal. They also eat omul (whitefish) and invertebrates, foraging mostly at night when the fish come closer to the surface. Once a year they will eat sclupin, a fish that lives in the silty areas of the lake. The silt and grit in the sculpin will scour the digestive system of the Baikal Seals, clearing out parasites. Foraging dives typically last 10 to 20 minutes, though Baikal Seals are capable of staying underwater for up to 70 minutes if they need to escape danger. The reason for this is that they have about two more liters of blood than other pinnipeds of comparable size, which allows them to hold more oxygen in their bloodstream.
The mating season of the Baikal Seals is towards the end of the pupping season. Their gestation period is only nine months, but they have delayed implantation, which means that the total pregnancy of a female Baikal Seal will last about 11 months. Typically only one pup is born, but sometimes there will be two. Pregnant females are the only ones who will haul themselves onto the winter ice, and that's only to give birth. The males and sexually immature females will stay underwater all winter, using holes in the ice to breathe.
Baikal Seals are considered to be a species of Least Concern, because while they can only be found in Lake Baikal, their population is estimated to be close to the peak capacity of the lake (about 100,000). Unfortunately, this means that a certain quota of Baikal Seals can be legally hunted every year, and they are also poached for their fur. They also face threats of pollutants entering the lake, like pesticides like DDT and hexachlorocyclohexane. No other Arctic or European seal population has been found to have such high levels of PCB and DDT. Climate change may also pose a serious threat to the Baikal Seal, as it will probably have a very severe effect on a cold water ecosystem like Lake Baikal.