A rare verified sighting of a northern fur seal in San Francisco Bay and the first-ever find of a spiny lobster in Lake Merritt in Oakland have been added to the list of anomalies in an El Niño year filled with them.

The previous week, a giant green sea turtle — a species more common along the inshore waters of Hawaii and Mexico — was seen and recorded in a video in the San Joaquin River Delta near Lathrop (San Joaquin County). The turtle had to swim through the Golden Gate and San Francisco Bay, which has never before been documented.

The fur seal was seen Nov. 21 by the Golden Gate Audubon Society during a nature trip on San Francisco Bay with Berkeley’s Dolphin Charters.

“We spotted a northern fur seal in the middle of the bay,” said naturalist David Assmann, the group’s guide. “While they are found on the Farallon Islands, seeing them in the bay is unprecedented in recent times.”

Bill Keener of Golden Gate Cetacean Research studied photos of the seal and verified its species.

“We have been involved in looking at marine mammals in the bay since the mid-1970s and we have never seen a live northern fur seal,” he wrote in an e-mail. “However, in the middens at the Emeryville shell mound, small numbers of fur seal bones have been found, dating from roughly 700 B.C. to 1300 A.D., so there is historical precedent.”

The spiny lobster at Lake Merritt might be an even stranger find. The lobster’s body was about 5 inches long, similar to those found off San Diego and Baja California, and was reported by Ray Perman, a volunteer with the Lake Merritt Institute. Lake Merritt, of course, is actually not a lake but is part of a tidal estuary with access to San Francisco Bay.

A year ago this week, a spiny lobster was caught and released twice on sport trips with Capt. Mike Rescino of the Lovely Martha out of San Francisco’s Fisherman’s Wharf. “We not only caught that lobster once and let it go,” Rescino said, “but then caught it (and let it go) again.”

Ray Perman/Ray Perman/Special to The Chro

There may be an explanation about the arrival of lobster in local waters beyond the suggestion that they have migrated here with the strengthening El Niño.

One evening at an East Bay restaurant, the manager spotted me, pulled me aside, and told me that a group of Buddhists bought all the live lobsters in the restaurant’s tank. He said they planned to release them to local waters as a ritual called “The Giving.” That could result in exotic species showing up in unusual locations.

Predators and pets

Responses to last Sunday’s column, “Sad ending to a missing cat mystery”:

Coyotes in cities: “I am the senior animal control officer for city of Palo Alto police, and have held this position for 36 years. The past three years, have witnessed, in my patrol district of Palo Alto, Los Altos and Los Altos Hills the first-in-memory coyote predation of domestic cats and sterilized feral cats in introduced colonies. I will share your timely article with our shelter staff. Your reporting on the predator-prey populations is valuable and appreciated.” — William Warrior

Face to face with cougar: “Mountain lions are so numerous in the west part of Napa that I’ve run into several different mountain lions on a number of occasions, most recently less than half a mile from my home in a dense neighborhood at 6:30 in the evening. My German shepherd lunged at the cat, so I got an up-close-and-personal look at it. My face was within four feet from the cat’s face. The cat turned around and jumped a seven-foot fence like it was nothing, and disappeared.” — Heidi Barr

Bolinas lion: “I took (a) photo yesterday (of lion scat) on the trail above RCA beach in Bolinas. I live nearby. The critters out here generally become more visible this time of year, abundant bobcats, coyote and a few mountain lions. We lost Lily, our young Abyssinian cat, to an owl a couple of years ago.” — George Gonzalez

Claremont bobcat: “I have sent you pictures of bobcat footprints on our property in the Oakland hills above Hiller Highland, as well as cougar prints off Claremont Canyon, but I never put two-and-two together. ... There are also three feral cats that are frequent visitors. You can see where this is going. The cats have not shown up on my (wildlife) camera for about a month, and after the rains, there were the bobcat tracks. ... Your article was really poignant and certainly a fair warning to people who may not believe that these cats are around.” — Bob Felton

Walnut Creek lion: “Last week I saw something I initially couldn’t explain. I’m used to seeing deer in my yard, so when I saw a deer quickly lugging another deer under a fence, I tried in my mind to figure out what was going on. Suffice it to say that I concluded, based on the carcass etc., and a little bit of research, the young deer was taken down by a mountain lion right in my own backyard. The lion left behind some remnants of the carcass, which I thought would disappear over time. Instead, I was completely surprised to find that the next morning there wasn’t one tiny bit of the animal left. Nature is sometimes cruel, fast and very clean.” — Mary Furman

San Francisco cats: “We have lived at the foot of Mount Davidson for 15 years, and when we first moved here we would see local cats in our backyard almost daily. Now we hardly ever see them, but we have seen a coyote in the yard twice now. That means that there have been coyotes there many times when we weren’t there to see them, no doubt.” — Meredith Serra

Fingernail evidence: “We found our beloved cat dead in our front yard. He had been attacked by a coyote, but he fought hard because both front claws were full of coyote fur. As my son likes to say, ‘He died with his boots on.’ We were told by animal control that the coyote was most likely startled into dropping his prey because, as indicated in your article, they usually take their victims back to their den.” — Tricia Lively

Surprise at vet’s office: “Around here, cats are called coyote bait. We live in Reno, in town, where we have curbs and gutters, not out in the country. Twice I have seen coyotes walking around on city streets in broad daylight. Once it was two doors down from our house. A neighbor told me he’s seen coyotes on our front lawn. ... A friend (who lives in the suburban area south of town) told me ... about the time she found a kitten in her yard. She took it to the vet to get its shots, and the vet told her she couldn’t keep it: It was a bobcat kitten!” — Janet Drozd

Voice of wisdom: “I volunteer at an animal shelter where we ask people, as a condition of adoption, to keep cats indoors. But not everyone does. I’m constantly telling friends to keep pets indoors or on the leash, and I’m sad to say at least two have lost either a cat or a small dog to predators. I’m so glad you brought home a new rescue cat, and she sounds like a love.” — Susan Slusser

Tom Stienstra is The San Francisco Chronicle’s outdoor writer. E-mail: tstienstra@sfchronicle.com Twitter: @StienstraTom.