BABY SEAL NUTRITION

Tavishi

Seals, like any other animal, need to eat. And like any other animal, seals don't always get the nutrition they need. The primary food of seals are fish. Depending on the species, the fish they eat will differ, but it remains that fish are their primary source of nutrition. When in captivity, different species of pinnipeds will still be eating the same species of fish regardless of region, as they have pretty much the same dietary needs. The exception here is most usually walruses, who have a diet of a lot more mollusks and tiny little critters than other pinnipeds, who are content with fish.

When seals are really young and not yet weaned, it is crucial that they be ingesting tons of calories, which they receive from their mother's milk. The amount of caloric intake from species to species differs. Typically, phocid milk is fattier and more energetic than otariid milk. (Phocid refers to the group of earless seals, or what you would typically think of when you think seal, whereas otariid refers to eared seals like sea lions.) As a result, phocid pups become independent much sooner than sea lion pups. A prime example is the hooded seal.

Hooded seal milk is the fattiest mil of any mammal, with about a 60% milk fat content. At this point, hooded seal milk is almost solid. But because of this, pups are able to gain weight fast, and with that, gain blubber quick, allowing them to survive the brutal colds of the Arctic. And within 4 days or so, pups are independent and gain anywhere up to 20 pounds. The amount of calories they consume is absolutely insane.

Replicating seal milk for pups in captivity is... hard. The Marine Mammal Center and other similar hospitals for seals receive a lot of patients who are too young to be weaned from their mother, and yet, are separated. While there are replacement milk formulas, a lot of times, hand made formulas are created. These formulas must be high in lipids, and contain absolutely no carbohydrates, at the risk of causing bacterial gastroenteritis to new babies. The Marine Mammal Center does occasionally use replacement formulas, but they often turn to what they call "fish smoothies", which is essentially blended up, high lipid content fish. The Marine Mammal Care Center, a similar hospital, primarily uses herring because of its high lipid content. When pups begin to sprout teeth, they start to wean and eat solid food. Depending on the species, this could be anywhere from 3-8 weeks.

This is Elmer, an extremely malnourished harbor seal pup who arrived at the Marine Mammal Center in 2023. I'm proud to say I have met Elmer in person, at a few months old. Unfortunately, Elmer was found to be blind, and thus could not be released into the wild, but is very happy and has two new seal friends at the Bahia Resort.

Walruses are very different from other pinniped species here. They need to be fed milk for around 19 months before they can start eating solid food. And rather than using fish smoothies, they get mollusk smoothies. Clams and other similar creatures blended up with whipping cream (to ensure enough lipids) create the milk replacement for baby walruses.

This cutie is a Pacific walrus pup rescued by the Alaska SeaLife Center also in 2023! Unfortunately, I have never met him in person, but I have seen the center, and a few of their current Steller sea lion patients. When pinnipeds are first born, it is crucial they are given attention 24/7. They'll need food pretty much every few hours in order to stay afloat. At the unweaned stage in their life, pinnipeds need to be fed around 10% of their body weight a day. For context, this is Germanium, who weighed 8.44 kgs at birth.

Germanium needed to be fed around 840 grams of food a day, if not more. That would be around 10 newborn kittens at the very least...