An eight-foot shark that ran aground on a Chilkat Inlet beach last week served as an interesting science project for schoolchildren, but will create a big stink if it’s not removed, a federal shark biologist said this week.
The meat of the Pacific sleeper shark contains a neurotoxin that scavengers aren’t likely to eat, said Dr. Cindy Tribuzio, a shark biologist with the National Marine Fisheries Service in Juneau. “It may just sit there and get really stinky. It may be best to tow it off the beach or bury it.”
Resident Gabe Lakey, out walking his dog on the popular stretch of beach near 1 Mile Mud Bay Road, came across the shark foundering in shallow water as the tide went out around 4 p.m. March 16. “It was struggling to get free. Its tailfin was flailing around, but it seemed like it was struck pretty good. When the tide went out, it gave up the fight.”
Lakey took photos of the creature, which he described as being in pristine condition, with no visible signs of injury or trauma, then started phoning around to try to identify his find.
After word about the shark spread, Mario Benassi, who leads an after-school science program for Haines students called “Chilkat Forest Investigators,” showed up with his third-grade scientists.
Although he didn’t plan it, dissection of the beast was inevitable, Benassi said. “It was the logical progression of the investigation. We had to cut it open. Then one of (the students) said, ‘Let’s look at the heart’ and it kind of took off from there.”
Besides identifying major organs, Benassi opened the stomach cavity, where they found lots of squid, some lampfish, and a hard, dark object that resembled a half of a mollusk. There were also dozens of translucent crystal-like “balls,” each about the size of a lima bean, which peeled like onions.
Biologist Tribuzio said the “balls” were likely lenses from eyeballs the shark had eaten. “They digest slower, so they tend to stick around for a while.”
The investigators also found the shark had sharp but tiny teeth, five rows on top and a single row on the lower jaw. “It had a body configuration of a serious predator, but not the teeth,” Benassi said. “For his size, he had much less teeth than you’d see in a typical salmon. You could tell it was eating more harmless creatures.”
Sleeper sharks get their name from a generally lethargic appearance when they’re hauled in by fishermen and are a “fairly common” bycatch in longline fisheries, Tribuzio said. Generally a deep water species in places like Hawaii, they spend substantial time in shallow waters in Southeast and Gulf of Alaska waters.
The sharks grow to 24 feet and one Juneau biologist said one 18 feet long was caught near Haines in the early 1960s. Tribuzio said it’s likely this one was not sexually mature.
It may have been hauled up from the bottom by a longline fisherman, as that fishery opened last week, or perhaps it was chasing the lampfish that have surfaced in Chilkat Inlet the past few weeks. “They can make a lot of vertical movement during the day. They move up and down a lot.”
Sleeper sharks can live as deep as 2,400 feet below the surface. Tribuzio said biologists have no information on how long they live or how big they are when they mature, or even how fast they reproduce.
However, their numbers may be on the upswing. Tom Rutecki, who also works for NMFS, said researchers in Chatham Straits couldn’t catch one of the sharks in the mid-1980s, but by the late 1990s were catching one on every 25th hook. “They went from not being around to being super abundant. Something happened in the ocean that was really favorable to these guys.”
Rutecki said the sharks are adept at eating black cod and halibut off longline hooks. He said they have green eyes. “They’re really interesting critters.”