No one knows who's to blame or where the shootings occurred.

As the number of sea lions confirmed shot in Puget Sound continues to climb, one group is staking out to try to find whoever is responsible.

"This is where I went last night. I went all the way down there," explained Chris Joyce.

Joyce has spent a lot of nights lurking in the shadows of West Seattle's shoreline. He is a member of Sea Shepherd, a wildlife protection non-profit. One of the spots he's spent most of his nights is a favorite hangout for sea lions because it's also a popular spot for fishing nets.

"The chinook salmon get caught in the net. What happens is that the sea lions come here, and they say, 'Well this is a buffet for us. We are just going to pick off all these fish that are sitting in the nets," said Joyce.It's what makes sea lions the adversary of many fishermen who battle over the same salmon. According to the National Oceanic and Atmospheric Administration (NOAA), it's common to find a few shot dead from fishermen this time of year, even though it's illegal.

Also see | 9 sea lions now confirmed shot in Puget Sound

But in the last couple of months, nine sea lions have been confirmed shot with a total of 16 washing ashore dead, most near West Seattle, Vashon and Bainbridge islands. It's a spike in deaths cloaked in questions without many answers. No one knows who's to blame or where the shootings occurred.

NOAA won't say much about the investigation, but Joyce says neighbors have tipped them off to a few areas in particular.

"'Hey there are gunshots at certain hours of the night, this is when it occurs, and we want to watch and see what happens,'" Joyce recounted. "We will not interfere. We just simply want to document and see who's doing it and get identification of individuals involved and turn it into law-enforcement."

Pressure is mounting to allow the killing of seals and sea lions as they compete for food with the endangered Southern Resident orcas. The Governor's Task Force did not include that in its recommendations to save the orcas.

Also see | Orca task force finalizes proposals to save Southern Resident killer whales

Sea Shepherd is offering $10,000 for information leading to an arrest, and another $2,000 for video of anyone shooting sea lions. Joyce plans to suspend the stakeouts until next year.

"Why? Because it's our mission to protect ocean habitats around the world and what they're doing is illegal," Joyce said. "Rounds could go into the neighborhood right here and hurt someone as well or kill someone, so there are a number of reasons we are here to stop this activity."

Anyone with information about the sea lion deaths should call NOAA's tip line at 1-800-853-1964.