Authorities on high alert after seal attacks in Plett
PLETTENBERG BAY - A thorough prevention plan has been put in place in Plett by various role players following several seal attacks on beachgoers along local beaches.
Although there is no certainty at this stage, the marine animals' behavioural issues are believed to have been caused by marine conditions.
Experts have urged beachgoers not to panic and to heed the warnings of authorities. "We have good systems in place to keep people safe, which is a priority," said marine scientist Dr Gwenith Penry.
Over the past weekend and earlier this week, several bathers, kayakers and other water users reported attacks by seals.
One incident was quite severe and involved a man who suffered lacerations to his leg after being bitten by a seal near Central Beach. Other reports came from along Robberg beaches.
There were also reports of an adult female seal acting strangely – hitting its head on the rocks – just before it died. It has not yet been confirmed whether the incidents are related.
Chanel Visser, CapeNature's senior marine ranger, said that it was initially thought that the animal was in distress after swallowing a fishing lure or had become entangled in fishing gear.
Upon closer inspection some fishing line was loosely bound around one of its flippers. Visser later also did a necropsy and no evidence was found that she had swallowed a fishing lure.
There were also no obvious signs as to why the seal had died.
Algal bloom
Penry said the seals' unusual behaviour could be related to an algal bloom. Algal blooms are quite common this time of the year – some of them harmful, others not. "It could be that the seals are consuming fish carrying a toxin from an algal bloom, which is causing a behavioural response," she said. Most of the algal blooms along our coast are not toxic or harmful.
She explained that it was similar to shellfish poisoning in humans. "If we eat lobster or mussels and other shellfish that have been exposed to a harmful algal bloom, we get sick."
She said in animals, the algal bloom could cause the animal to feel unwell, stop eating and die of toxicity.
"We haven't confirmed that these recent incidents are definitely from a harmful algal bloom, but evidence is pointing that way.
It is very difficult to test for and requires analysis of fresh brain and urine samples which we only get if the animal dies."
Penry added that this algal bloom would pass. "We often have them, especially during upwelling caused by easterly winds."
Precautionary measures
She said that as a precautionary measure, local lifeguards and shark spotters would be monitoring the areas for seals "overlapping" with bathers. "Swimmers will be pulled out the water, should seals be spotted in the vicinity."
Over and above these authorities, the NSRI, Bitou Municipality and medical professionals know about the incidents and are ready to assist where necessary.
Visser said it was important to note that should anyone be bitten by a seal, it cannot be treated with normal antibiotics.
"There is a lot of bacteria in their teeth and mouths and [a seal bite] requires treatment from a medical professional," Visser said.
Local seal diving operators also have strict protocols in place before allowing anyone in the water, including assessing seal behaviour.
"From the research community, we will be sampling dead seals that wash up and ensure that the correct samples are taken. This is to test for any possible toxins in their bodies relating to this unusual behaviour."
Penry said the seals’ unusual behaviour could be related to an algal bloom. Algal blooms are quite common this time of the year – some of them harmful, others not.