San Diego Dolphin Deaths Prompt Year Long NOAA Investigation

Three dolphins were stranded on the Silver Strand in October 2015; a year later a report suggests the Navy sonar could be to blame

In San Diego County, two Bottlenose dolphins were found along the Silver Strand in October 2015.

The first, a male, NEB0075, weighed almost six hundred pounds. Two hours and forty minutes later, about a mile away, a female was found. Almost nine feet long, KXD0280 is how she was identified.

Finding two dead dolphins, stranded in the same general area, in the same general time frame is a rarity in the San Diego region, according to national data. On average, according to the National Oceanic and Atmospheric Administration (NOAA), each year, 3.3 dolphins are found stranded along the San Diego coast.

These two dolphins, found stranded within hours of each other, is an “unusual event,” according to federal investigators. The last time two dolphins were found dead, stranded along the coastline, was in 1963. Those deaths were never explained.

Nine days after these two dolphins were found, a third dolphin, identified as KXD020 was found. This one stranded near Naval Amphibious Base Coronado farther north along the Strand.

When sea mammals are found stranded, a stranding report is created to alert NOAA and the National Marine Fisheries Service. The report for the female dolphin, KXD0280, indicates she was not pregnant.

Click here to read the report on the male dolphin found. Click here to read the report on the female dolphin.

Southwest Fisheries Science Center, based in La Jolla, examined all three dolphins. The first two necropsies were completed in the Center’s lab. KXD020 was found in “moderate decomposition” so his organs were removed at the beach and returned to the Center for review.

When first learning about the dolphin deaths in October 2015, NBC 7 Investigates submitted a Freedom of Information Act request to NOAA for copies of the stranding reports and any other documents pertaining to the investigation into the dolphin’s deaths.

It would take a year and a series of discussions between NOAA, the National Marine Fisheries Service and NBC 7 Investigates before the preliminary report and documents were released.

Click here to read the complete report. 

The documents list potential causes of death as a boat collision, shot fishery interaction or other human interaction. They also show the U.S. Navy was involved in a training exercise during the same time frame roughly in the same area, the dolphins were found stranded.

One of those documents, an email from Jaclyn Taylor of NOAA, confirms this. According to the email, a “Navy Major Training Exercise” was underway during the timeframe the dolphins stranded.

“So, clearly they are operating out there,” confirmed another email from the California Stranding Network Coordinator, Justin Viezbicke. In his email, he noted the Navy notification “didn’t contain the normal 72 hour pre-notification.” Viezbicke was told by his Navy contact that travel “delayed the email and the event started on Oct. 21.”

Click here to read the emails. 

The Navy agreed to notify NOAA as part of a long running legal battle over the use of sonar. Federal courts have said the “least predictable adverse impact” should be part of any Navy planning and training.

This mandate is part of a court enforced authorization from NOAA and the National Marine Fisheries Service which allows the Navy to use sonar in certain sensitive marine areas.

Click here to see maps of the where sonar is allowed and where there are restrictions.

The emails continue, describing how the Navy was investigating the issue. In one email, the Chief of Naval Operations, Washington , D.C., said, "the Navy has been collecting information" about a military exercise in the Hawaii-Southern California Testing and Training (HSTT) Study Area. According to the emails, there was "NO explosive use" in the exercise, "hull mounted MFA sonar” was used within "72 hours and 80 nautical miles” of the strandings.

In response to NBC 7 Investigates, the Navy answered questions via email but declined an on-camera interview. In the email response, a Navy spokesman said, "...the MTE in question was conducted without the use of sonar and explosives. When conducted without the use of sonar and explosives, the event does not produce any acoustic stressors which can affect marine mammals or their potential to strand...The Navy has been consistent in providing NMFS with required 72-hour pre-event notications during the HSTT training and testing activities covered under the current authorization, as well as under the previous authorization since 2009."

Attorney Joel Reynolds with the Natural Resources Defense Council, NRDC, has been involved in lawsuits with the Navy over its use of sonar since the mid-1990s. He reviewed NOAA’s report on the dolphin deaths.

“The NOAA report suggests a lot of circumstances we have seen many times in the past in the wake of high intensity sonar testing and training,” he said.

The sonar in question is called, MFA or mid-frequency active sonar with mid-frequency referring to the pitch of the sound waves. According to the report, MFA was used in the training session, one day for 35 minutes and another day for a total of 62 minutes.

According to the NOAA report, the dolphins "were all impacted by the same acute event" within a short time frame. The necropsy completed by Southwestern Fisheries ruled out algal bloom toxins, which have killed dolphins in the past. According to the documents, they found internal bleeding around the heart and in the abdomen, as well as head trauma.

"A specific cause of death has not been determined from the study," according to the investigative report but suspected causes of death noted in the report include the dolphins being trapped underwater by a net or a cage or mid frequency active sonar. The report also notes there was no commercial fishing in the area and "one would think the force of the struggle" would leave some abrasions or lacerations on the dolphin's body but there weren’t any.

The problem with the active sonar being named as the cause, according to the report, is "hemorrhage around the ears might be expected,” but there wasn’t any. "However it is important to note" continues the report, this happens with beaked whales and it could be different for bottlenose dolphins whose "behavior and habitat" differ from whales.

According to the conclusion of the report, "all three dolphins clearly suffered severe trauma" likely man made in nature, "although the exact cause is unknown."

According to the email from a Navy spokesperson, the Navy conducted its own analysis and “is confident that these stranding events were not caused by the Navy’s use of MFA sonar.”

The response continues, saying, there was “no realistic probability that the stranding was caused by the Navy’s use of sonar. The closest Navy sonar-using ship was (about) 6 nautical miles (11,100 m) away from the stranding location...Based on the significant distance between the MFA sonar use and the dolphins’ habitat, as well as computer modeling of the likely propagation of the sonar within the area in question, the Navy is also confident that its use of MFA sonar could not have caused behavioral reactions that would lead the animals to strand.”

Click here to read the Navy’s complete response. 

Paul Watson, an environmentalist with Sea Shepherd, an international marine wildlife conservation organization, said this has happened before. According to him there can be unknowns when dolphins and sea mammals are found stranded.

“A lot of the bodies simply aren’t found,” he said. ”The best way to liken this (sonar injuring or killing sea mammals) is a human stands beside a 747 jet engine. Multiply that about five times, you will get the kind of impact it would have on a human being.”

“It causes internal bleeding,” Reynolds said. “The animals lose their bearings, frequently leading to stranding and them dying on the beaches.”

According to the email sent by the Navy, the location these three dolphins were found stranded, “located outside of the busy harbor of San Diego,” they “would likely already be sensitized to small boat and shipping noise, as well as naval activity, including the use of active sonar.”

Referencing a 2000 incident in which 17 whales swam themselves aground in the Bahamas the NRDC said, a report published more than a year after the 2000 incident concluded mid-frequency sonar emitted by the Navy caused “some sort of acoustic or impulse trauma” that drove the whales to shore.

NOAA declined NBC 7 Investigates request for an on-camera interview. Instead the agency answered a series of from NBC 7 Investigates via email. Click here to see the Q&A.

The Navy depends on sonar to protect its ships at sea. It uses the sonar to bounce loud sound waves off of objects to detect enemy submarines.

Reynolds told NBC 7 Investigates he recognizes the importance of sonar in order for the Navy to protect the fleet and the homeland but “when the animals are there in significant areas, feeding area and breeding areas, migratory paths; test someplace else.”

Click here to see a documentary produced by NRDC on the use of sonar underwater.

While producing this story, NBC 7 Investigates learned of other sea mammal strandings in our area, according to NOAA and the National Marine Fisheries Services. More information on those is below:

  • On July 1, 2016, a California sea lion carcass was discovered in the vicinity of Silver Strand South. The discovery was made shortly after, and in the vicinity of, the Navy's use of permitted high-frequency active sonar. NMFS has initiated a review of the event.
  • On June 16, 2016, a California sea lion carcass was discovered at Coronado Naval Amphibious Base. The discovery was made shortly after, and in the vicinity of, the Navy's use of permitted high-frequency active sonar. NMFS has initiated a review of the event.
  • On March 30, 2016, a seal or California sea lion carcass was discovered at the Naval Base San Diego piers. The discovery was made shortly after, and in the vicinity of, the Navy's use of permitted mid-frequency active sonar. NMFS has initiated a review of the event.
  • On March 4, 2016, a dead floating humpback whale was reported offshore Point Loma, CA, which NMFS identified as an Uncommon Stranding Event. The Navy verified permitted mid-frequency active sonar use within 72 hours before the stranding and 80 nm of the stranding site. NMFS has initiated a review of the event.
  • On March 10, 2016, two California sea lion carcasses were discovered at Silver Strand Training Complex-North Beach. The discovery was made shortly after, and in the vicinity of, the Navy's use of permitted high-frequency active sonar.
  • On February 19, 2016, Navy personnel discovered a live, emaciated juvenile California sea lion at Coronado Naval Amphibious Base. The discovery was made shortly after, and in the vicinity of, the Navy's use of permitted high-frequency active sonar NMFS has initiated a review of the event
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