The National Oceanic and Atmospheric Administration (NOAA) Fisheries announced Wednesday that a satellite-linked dart tag improperly managed caused the death of an endangered Puget Sound orca in March. The 20-year-old male whale suffered from a fungal infection that led to its death. Its body was found off Vancouver Island with tiny pieces of a dart tag in its dorsal fin.

Federal biologists fired transmitters the size of a 9-volt volt battery into orcas in February 2016. They have been doing this for about a decade, and their goal is to track where they go in winter and find out why their populations are declining. They believe there are other reasons in addition to threats from pollution, the disturbance caused by boats and lack of prey. There are currently 82 orcas left in Puget Sound.

Orca GPS tracking
“The most recent estimate places the global orca population at a minimum of about 50,000 animals,” said NOAA. Image credit: Mark Thiessen.

The transmitter is taped to a pair of titanium darts about 2 inches long and is designed so it can slowly work its way out the dorsal fin and leave nothing behind in the whale after weeks or months.

This technology allows scientists to gather valuable information about the animal behavior when they are too far away to be seen or tracked with traditional methods. The data collected contributes to conservation efforts.

Tags similar to the one attached to this whale, called L95, have been used over 530 times by as much as 19 species such as pilot whales, grays, find, beaked whales, humpbacks, and 56 killer whales. Eight Puget Sound orcas have been involved in the tagging program. The scientist in charge of pulling the trigger to target L95 is absolutely experienced.

However, something went wrong, and the whale was hurt. The necropsy found that the orca’s bloodstream suffered a fungal infection at the spot where it was shot. The devastating incident may have been caused by a tag that was not sterilized or maybe the device was contaminated once it came into contact with the water.

Another possibility is that the fungus was already present on the whale’s skin and aggravated because of the dart’s fragments left behind in its body, according to the examination, which was reported by CBS Baltimore.

British Columbia pathologist Stephen Raverty performed the necropsy which revealed that the fungi concentrations were significantly largest near the dart’s entry point. The infection eventually made it to the lungs, causing the whale’s death, as reported by National Geographic.

The report by NatGeo reads that the winds were tough and the waters rough on the day the biologists shot L95. They even had to shoot it twice because the weather conditions complicated their task, which could have contributed with their neglection at sterilizing the Dart with alcohol the second time.

Benefits of tagging marine creatures may outweigh the mild risks

The satellite tagging program has been suspended until the agency has finished its review into the case. NOAA’s Northwest Fisheries Science Center in Seattle is also planning to establish an independent panel to discuss weather satellite tagging of orcas in Puget Sound should continue. A special Workshop for the 88 country International Whaling Commission is being planned to talk about tagging efforts around the world.

Additionally, the agency’s office of protected resources will review whether extra conditions should be implemented to reduce injury or infection to fully guarantee that future whales, dolphins, and other cetaceans are protected during tagging efforts.

Orca GPS tracking
Dr. Russ Andrews (Alaska SeaLife Center) (with air gun) crouching on the frozen ice in McMurdo Sound, Antarctica, preparing to attach a satellite tag to the dorsal fin of a killer whale. Image credit: NOAA.

“It’s devastating to think this could have happened,” expressed Brad Hanson, the biologist who directs the Orca tagging program, according to CBS. He added that he was completely responsible for failing to make sure the tag was really sterilized.

The program has provided crucial information and a great amount of data about the animals in a short period, Hanson said. He helped start the operation ten years ago, and the team has been able to collect prey and fecal samples.

Whale protection activists see the tagging program as barbaric

The Wednesday announcement confirmed that the tag clearly affected the whale’s health, but there are some factors that could have increased the risk of infection through the dart. The Nat Geo article explains that the immune system of the animal may have been weakened already before it was shot due to the population’s decline of salmon, the prey that the whales from that specific area primarily feed on.

Also, L95 was already nearing the median age of death for a male in its community. Ken Balcom, a senior scientist with the center for whale research Inn Friday Harbor, claimed the use of the tag was barbaric and risky, according to NatGeo.

Advocates who criticize this method believe there are less invasive ways to collect data from small population of whales such as using underwater acoustic monitoring. Canada emplys this technique to track orcas.

Source: National Geographic