14 Dead Seals?

QUESTION

A woman and her husband took a walk on the beach on Sunday late afternoon, just past Strandfontein pavilion, off that car park where the fishermen cool off. They counted 14 dead adult seals on the beach, 12 had been decapitated and most were missing fins or had large chunks of skin torn off them. She said she is used to seeing maybe 1 dead seal, but found 14 very strange, yes she is a DSTV national geographic fanatic. Is this normal? It sounds like white sharks, well due to the proximity to seal island and the onshore that's been blowing, but why would apex predators leave their prey to float into the beaches?

ANSWER

It's always good to pass on this information because you never know. In this case the dead seals aren't surprising because this happens every year at this time. Usually it's seal pups because Dec/Jan is the breeding season for them and due to limited space and overcrowding on the island and the helplessness of the pups within their first few weeks of being born (blind and can't swim), strong SE winds and swell wash hundreds (and in some years thousands) of seal pups onto our beaches.

However, the stress and energetic costs of breeding by males and females and maintaining territory's by fighting by males results in stampedes which result in many disturbances on the island. These all take their toll on the adults too.

After many days of strong SE we often see the spikes in dead seals that have succumbed to the stress and due to large swells get washed off the island. This happens at other colonies along our coast too. The large chunks of skin that look torn, missing limbs and head can mostly be explained by decomposition and scavenging by various marine animals as these soft bits between limbs and head always decompose faster resulting in what looks like decapitated animals.

Interestingly, I have seen many a white shark turn up their nose at these dead animals, even if it's an easy meal, they tend to be picky when it comes to preferring fresh seal :).