Thousands of fish swarm into a huge shimmering ball - making a last desperate play for survival against an onslaught of dolphins and sharks. British Wildlife photographer Christopher Swann swam in the midst of this frenetic battle of life and death to capture these images off the coast of the Azores in the Atlantic Ocean.



The vulnerable mackerel instinctively cluster together seeking safety in numbers from the hungry predators.



Short-beaked common dolphins (Delphinus delphis) hunting blue jack mackerel (Trachurus picturatus).



It was a fabulous - like being among a cloud of starlings, said Christopher Swann, who comes from Brighton. It just went on and on.



I cant say how many, added Christopher, but there were many thousands. It was approximately 30ft diameter at its maximum and at least as deep.



But as the shoal flees from deeper waters towards the surface, clusters of Cory's shearwaters begin to dive-bomb them from above. Left with no escape, the blue jack mackerel have little choice but to wait until the pod of short-beaked common dolphins have had their fill.



Bait balls are common among many small schooling fish, such as sardines, and can reach huge sizes of up to 20m in diameter.



Cory's Shearwater (Calonectris diomedea) hunting blue jack mackerel (Trachurus picturatus).








source