Hello, Brynjar; it's a pleasure to make your acquaintance. I have given your entry a quick scan, and I am very impressed! Well-researched, well-written, extremely detailed, and thoughtfully and artfully constructed, your entry could have come from a veteran developer.
A few small things to consider:
1) Consider deleting the second comma: "Hearing is the ardol’s primary sense, and they rely heavily on it when they are out of the water, and vulnerable to land predators."
2) Consider splitting this sentence in two, the second specifying the danger to pup: "The blue-tongue is not a top predator of the north ice, and often falls prey to other predators, such as: the snow wolf, pinnip, white bear, carcal wild cat, dark stryke shark, the reintroduced Eanian warg, and pups are especially vulnerable to the snynx fur snakes." [You might also mention poachers here].
3) In your lore, you mention it was elves who over-hunted these darling little creatures, but consider that this is quite out of character for elves, who are accustomed to living harmoniously with nature. Perhaps it might have been some human tribe instead?
4) Generally, we capitalize the name of the creature in the entry (Blue-Tongue instead of blue-tongue). I assume the convention still holds, but I do not know for sure. Perhaps Artimidor can clarify.
A really spectacular entry, with so many rich details. I look forward to seeing more from you. If you have any questions or need any assistance, don't hesitate to ask. While most of my knowledge is likely antiquated, obviated, or forgotten, perhaps it might still be of some use.
And as it hasn't yet been my pleasure to say so, Welcome to Santharia.