Pain bearers: The 35 highly venomous box jellyfish netted along Batu Ferringhi after marine scientists towed a special net for 650m at about 200m from the shoreline on Jan 12.
GEORGE TOWN: Swimming off Penang’s beaches can bring you a world of pain.
Marine scientists were stunned when they caught 35 highly venomous box jellyfish after trawling a special suspended net for a mere 650m stretch about 200m from the Batu Ferringhi shoreline.
They were of the species Chiropsoides buitendijki.
Stings from a buitendijki will cause many hours of burning pain throughout your body, although they are not as lethal as the Australian Box Jellyfish, which can kill humans in three minutes.
Most people stung by the buitendijki must be warded to remain stable, especially if they suffer from comorbidities like diabetes or hypertension.
First reported in Penang waters in 2017 by marine scientists, only a handful used to be found.
This is the first time 35 have been caught in a single sweep of the scientists’ net – this all happened on Jan 12, and three more were caught off Tanjung Bungah that day.
Universiti Sains Malaysia (USM) Centre for Marine and Coastal Studies (Cemacs) director Prof Datuk Dr Aileen Tan said in their previous samplings from August to December last year, they only netted one such specimen per trip.
“However, at about 10.32am on Jan 12, we netted these 35 specimens of Chiropsoides buitendijki. It is worrying,” she said.
Explaining that jellyfish were passive swimmers or drifters, Prof Tan said their presence close to the beach depended heavily on current and tidal conditions.
She said after this spike in numbers, Cemacs’ medical scientists in the Jellyfish Research Team had raised an alert.
On Feb 7, Penang’s Fisheries Department posted a public caution to swimmers on Penang beaches, warning them of severe jellyfish stings.
Prof Tan said subsequent monitoring after the 35 were caught showed that box jellyfish numbers had resumed to the normal one or two each time, but the extreme spike on Jan 12 meant that beach-goers must be warned because a calm day at sea might see box jellyfish drifting towards the beach.
“Regular monitoring only started in 2017, and in the last five years, the frequency of box jellyfish sightings has doubled or tripled,” she said.
Prof Tan believes venomous box jellyfish began growing around Penang because there was more “food” in the water: run-offs of fertiliser directly foster the proliferation of jellyfish larvae.
“During heavy rain, there would be more agricultural run-offs carrying nutrients into the sea, leading to plankton blooms.
“This increase means more food for jellyfish larvae. Added to the ability of jellyfish to reproduce sexually or asexually, this leads to rapid reproduction,” she said.
To tackle the threat of jellyfish in Penang, Cemacs senior science officer Sim Yee Kwang developed a mobile app to help with data collection through citizen science.
Last December, his team of students from Universiti Malaya (UM) and Universiti Kebangsaan Malaysia (UKM) won the 7th edition of the Ocean Hackathon in France for the app.
It collects data of jellyfish abundance and data from long-term monitoring by Cemacs to predict the blooming periods of jellyfish around the coastal areas of Penang.
The competition, which centred on developing prototypes driven by digital data to solve complex oceanic challenges, was organised by the Embassy of France in Malaysia.
UKM Emergency Medicine Department senior medical lecturer and consultant Prof Dr Ahmad Khaldun Ismail, who specialises in clinical toxinology, said the severity of venomous jellyfish stings varies between species and can cause many different reactions in humans.
He said deaths by jellyfish in Malaysia were recorded from stings of the Chironex species.
“However, these stings are still poorly documented due to the lack of interest, funding and research,” he added.
As the severity of stings may vary, Prof Ahmad Khaldun said the multi-tentacled box jellyfish Chironex yamaguchii was recently identified as the probable main cause of jellyfish deaths in Malaysia.
Penang Fisheries Department director Yazeereen A. Bakar said her department had advised the public to exercise extra caution when swimming off beaches here.
