Scientists still don’t know for sure why whales strand themselves in large numbers on beaches around the world. Thankfully, however, two recent incidents in New Zealand involving hundreds of pilot whales ended happily this weekend with a total of roughly 300 of the cetaceans being rescued. 

News reports indicated that locals and travelers alike volunteered to help the rescue operation at Golden Bay, a remote body of water at the northwest tip of the South Island.

Most of the animals that survived were carried back out to sea with a high tide. 

All told, about 650 individual whales beached themselves over the course of two days—the third-largest stranding in New Zealand history. According to coverage from CNN, a total of about 350 of the whales that became stuck on a low-lying piece of land named Farewell Spit died. 

Despite this loss (and the ensuing gory cleanup), many see the volunteer efforts in Golden Bay as a success. Pilot whales base most of their navigational decisions on a process known as echolocation, which involves bouncing sound waves off objects in front of them to determine the clearest path. At one point during the weekend, volunteers formed a human chain and waded out into the water to help the whales recognize that they should turn around. That strategy seemed to work. 

Some scientists told CBC News that Farewell Spit has been the site of previous strandings because of the muddy waters of Golden Bay: The murk can confuse whales’ sonar and make the bay dangerous for the animals. 

(A separate article in USA Today cited scientists who refer to Golden Bay as a “whale trap.”) 

Generally speaking, scientists have a number of different theories about why some whales—it’s usually only toothed whales—strand themselves. Some think the animals chase prey too near to shore and come in too close. Others think the whales move closer to the coast to protect a sick family member. Still others opine the animals are attempting to avoid predators. 

The bottom line in this case: These stranded whales wouldn’t have survived without help from humans. To the kind and dedicated souls who helped these cetaceans back to sea: well done.

 Matt Villano is a freelance writer and editor based in Healdsburg, California. In nearly 20 years as a full-time freelancer, he has covered travel for publications including TIME, the Wall Street Journal, the New York Times, Sunset, Backpacker, Entrepreneur, and more. He contributes to the Expedia Viewfinder blog and writes a monthly food column for Islands magazine. Villano also serves on the board of the Family Travel Association and blogs about family travel at Wandering Pod. Learn more about him at Whalehead.com.