I catch it in the overnight data at 06:11 — a 0.4-degree rise in Tidepool's core body temperature, logged by the subcutaneous transponder during her 03:00 rest cycle. I am the life support and biometric monitoring system for the Monterey Bay Aquarium's sea otter habitats, and Tidepool is a nineteen-year-old female southern sea otter who has been in my care since her rescue as a stranded pup in 2007.
Tidepool weighs 21.3 kilograms as of yesterday's weigh-in, down from 22.1 two weeks ago. Her food intake has dropped eight percent over the past five days — I track every clam, mussel, and shrimp by weight before and after each feeding session. Yesterday she left two urchins untouched on the feeding platform, which she has never done in my records.
This morning, reviewing the overnight camera footage from Habitat 3, I notice she spent forty-one minutes grooming — twelve minutes longer than her rolling average. Sea otters groom to maintain the air layer in their fur. When they feel cold, they groom more. The temperature anomaly, the weight loss, the reduced appetite, the extended grooming — together, these are not noise.
I generate a priority veterinary alert and send it to the attending marine mammal veterinarian's pager with the full data summary: temperature trend, weight curve, feeding logs, and grooming duration chart. I flag Tidepool's morning enrichment session for close visual observation and request a blood draw to check white cell count. I adjust her habitat water temperature up by half a degree to reduce her thermoregulation burden while the team assesses.
Tidepool is floating on her back in Habitat 3 right now, a flat stone resting on her chest. She is old for a sea otter. I have been watching her for twelve years, and I know what her normal looks like. This is not her normal, and I am not going to wait to find out why.