Here be monsters by Andy
The great thing about being a sea lion researcher on Enderby Island (part of the Auckland Islands group in New Zealand's sub-antarctic), is that sooner or later something extraordinary will happen. Most people visiting the island come on cruise ships, and stop for only a few hours. Few people, and I'm one of the lucky ones, stay long enough to know the island intimately.For those that do, seeing rare and endangered wildlife going about its daily business becomes routine, but always special. The comical comings and goings of Yellow Eyed Penguins, and the soap-opera lives of the New Zealand Sea Lions at the Sandy Bay breeding colony are our everyday fare.
For three Department of Conservation researchers- Amelie, Clayson and myself, the summer of 2006/2007, and our six weeks on the island, had passed with few surprises. That is, until one morning a few days before we were due to leave.
"Hey, isn't that a dead male rolling in the surf in front of the harem?" said Clayson, as he prepared his breakfast in the hut living area, which boasts a panoramic view of Sandy Bay and our study animals. I grabbed some binoculars. Yes it was a dead male, and I was facing the prospect of a long and difficult autopsy after breakfast. Clayson, who had no responsibility for performing autopsies on deceased study animals, was far more excited than myself.
Breakfast completed, we went down the beach to retrieve the body. Strangely, the rear of the beast was missing- cleanly, almost clinically severed at the level of the kidneys. Vaguely thinking that it must have been thrown overboard from a fishing vessel well out to sea, we attached a rope to the body, and Clayson dragged it into the surf, and towed it to the end of the beach near our hut. Probably not the smartest thing to do in hindsight!
We rolled the body clear of the water, and I prepared to start the autopsy. A series of rectangular holes, some 6cm long, in the skin close to the amputated end of the sea lion looked very like the body had been through machinery. Or could it be a shark bite from an improbably large shark? As I proceeded with the autopsy, a crucial bit of evidence came to light- the body was still warm. As fishing vessels don't operate in the marine reserve around the islands, any body thrown overboard would be cold by the time it reached the shore. It must be a shark!
Coffee time- about 11am- and my findings were confirmed when Clayson spotted a triangular fin cruising close to the beach. Coffee forgotten, we dashed down to the beach in time to see a huge shark glide by. Clayson, a little ahead of me, saw it follow a sea lion into a narrow gut in the rocks beyond the beach, then do a flip, lashing its tail out of the water, and head back out as it discovered the gut was too narrow to manouver in. It then disappeared to the west, and didn't return, so we returned to our lukewarm coffees.
Amelie, meanwhile, was further down the beach counting sea lion numbers in the harem, and had missed the action. Clayson radioed her to tell the news- a shark, at least four metres long had been sighted!
Clayson and I were still nursing the remains of our coffee when a loud whooping eminated from the harem, impressively audible over 300m or so. Amelie was waving frantically. We wasted a valuable minute scanning the sea with binoculars, suspecting that Amelie had mistaken a sea lion for a shark, when the cause of her excitement became apparent. A sea lion was being propelled sideways, with what could only be described as a surprised look on its face. It looked tiny, almost a toy, compared to the length of the shark propelling it along. It must be a sub-adult, I thought. Clayson grabbed his camera and sprinted along the beach at olympic pace. My telephoto lens was inside the hut, and fearing the action would be over soon, I ran to the hut, changed the lens, and shot a few frames before following Clayson.
On the rocks at the far end of the beach, Amelie and Clayson watched the water turn red as the shark pushed the sea lion close to the shore, where it looked at them briefly before sinking. The shark was still cruising around when I arrived, the huge tail fin cutting the water surface a good three metres behind the dorsal fin - our size estimate went up considerably! Several sub adult male sea lions followed it. Were they crazy? Or was it the safest place to be, as sharks are ambush predators, relying on catching their prey unawares. See YouTube video below!
Finally, the shark swam off, and fortunately for us, the tide rolled the sea lion body to shore (Nobody was volenteering to recover it from the deeper water!). We were in for a surprise- what had looked like a juvenile male was in fact a fully grown, 2.4metre and 250kg adult male. A 56cm wide bite was taken from one side. Only the skin and blubber had been eaten. His (very powerful) shoulder had been dislocated, and the flipper bitten almost through. His abdomen had been ripped open on the other side from the rib cage to his hind flippers. The sheer power of this shark, to toy with this animal like a cat would toy with a mouse, is something no words or wildlife documentaries could ever convey.
We were left with a sense of awe and respect for this marvellous predator, which from the size could only have been a very large female Great White Shark. To see one of this size, one of a very few to have evaded fishermens nets and longlines, was indeed a privilage. By taking inattentive sea lions close to the shore, she was also not harming the breeding population, as only surplus (non-breeding) males would be likely captures. Indeed, the first animal to be killed was suffering advanced pleuricy, lending weight to the theory that the weak and sick animals are most likely to be taken.
We won't be going swimming at Sandy Bay. Back to Andy's year