Whale-watching season has begun, and much as in previous years, a few whales have already been sneaking into San Francisco Bay, likely to feast on anchovies. But one whale who's been hanging out in the Bay since February looks possibly unhealthy.

With all the shipping, commercial fishing, and recreational boating traffic in the Bay, it's not really ideal for whales to be coming into it. But in recent years it's happened with some frequency, with both smaller gray whales and their larger humpback cousins. Marine biologists have suggested this is in part because of schools of anchovies coming into the Bay — the humpbacks' favorite food — driven by larger changes in ocean temperatures. But, also, growing whale populations in the Pacific mean there's more competition for food on their annual spring migration north toward Alaska, and some whales who have found good eats in the Bay before remember to take a pitstop here on their way north again.

For gray whales, the Bay is just that — a pitstop — with little to no high-quality food here for them. Gray whales, who tend to live in shallower coastal waters, eat a variety of benthic and epibenthic invertebrates from the seabed, sucking them up from the sediment there.

The Sausalito-based Marine Mammal Center noted the first gray whale sighting of the year on February 9, saying at the time that the whale was in "seemingly good body condition."

But that same whale, who's been identified multiple times by distinctive fluke markings, has now been in the Bay for a record-setting 70 days — the previous record, as the Chronicle reports, was 46 days.

And the whale's body condition seems to have deteriorated, showing signs of sea lice and weight loss.

This isn't the first gray whale to delve deep into the Bay and stick around. As Bill Keener with the Marine Mammal Center tells KPIX, "A lot of them show up kind of starving or skinny in our area, on their northbound migration, and they turn in to San Francisco Bay, using it as some kind of migratory stopover is our best guess. It's calm waters in the Bay, and they rest for a while."

Whale-watching season also comes with the grim reports about dead whales washing ashore, which have already begun. Whales' deaths can be caused by malnutrition, ship strikes, or other factors, and one whale carcass washed ashore this season already in San Leandro, and another in Bolinas.

Prior to 2015, when SFist noted a "crazy" number of whale sightings, humpback and gray whale sightings in the Bay were rarities, but there have been around 100 sightings — possibly many of them of this same sick whale — since February this year. Gray whales were typically considered "lost" if they ventured into the Bay a decade ago. One gray whale mother and her calf ventured 90 miles up the Delta and the Sacramento River in 2007, captivating the Bay Area before finally turning around and making it back to the Pacific.