In what looks strangely reminiscent of a twister touching down, this giant shoal of sardines has been captured by divers exploring a reef in the Philippines.
The magnificent twist, known as a 'sardine run', sees the fish swim in formation to create a shimmering wall in as part of their annual migration. The sardine run can see shoals up to 4.3 miles long, 0.9 miles wide and 30 meters deep.
The natural phenomenon occurs in the region from May through to July when billions of sardines spawn in the cool waters off the coast of southern Africa and move north along the east coast and into the Indian Ocean. This shoal, captured by photographer Nadya Kulagina, was spotted near Pescador Island.
“We were exploring the abundance of marine life - frog fish, moray eels, octopi, sea snakes when suddenly the sky grew dark as if overcast with unexpected clouds,” she said. "I looked up and there were thousands, no millions of sardines moving as one organism. Their moving mass was blocking the sun turning day into night."
The incredible set of photographs shows the sardine run as it twists through the ocean, creating a giant wall as it moves. Nadya, who caught the shoal on the last dive of her trip, described it as “so mesmerising that everyone froze to watch the monster in action”.
“We would swim into the shoal and lose track of reality not being able to tell which way was the sky or the seabed," she said. “The shoal was so powerful it kept pulling us down and further off course. I was trying hard not to lose sense of direction.
"It also kept changing shapes, one minute it would open wide and the next shrink into a tight ball."