WEDNESDAY, MAY 22, 2024
Dolcy D’Cruz
Believed to be older than dinosaurs and have existed on earth for more than 500 million years, Jellyfish are extremely important marine creatures that have significant effects on the structure of the global marine plankton ecosystems. They do not have a heart or bones in the body. However, they have a central nervous system and a mouth which is located in the middle of the body. Today, November 3, is celebrated as World Jellyfish Day which makes it apt to learn more about this alluring yet very harmful marine organisms.
Dr Biraja Kumar Sahu is a scientist in the department of Biological Oceanography at CSIR-NIO (National Institute of Oceanography), Dona Paula. He informs that there are different types of jellyfish observed on the Goan coast. “In Goa coast, the common jellyfishes are Rhizostoma pulmo (barrel jellyfish), Chryosoara sp, Acromitus sp, Aurelia aurita (moon jelly), Phsalia physalis (Portuguese man-of-war), Porpita porpita (blue button jelly) etc. On the west coast of India, swarming of jellyfishes were mostly observed towards the end of the southwest monsoon (June to September). Swarming of some jellyfishes starts at the end of monsoon and it remains in water till January. Some other species like Acromitus swarms in summer season. Portuguese man-of-war were observed in monsoon seasons along Goa coast,” says Dr Biraja.
Elaborating on the studies undertaken at CSIR-NIO, he informs, “A study is underway that fully focusses on the jellyfishes of Goa coast. The study is funded by Ministry of Earth Sciences. It will catalogue the different types of jellyfishes observed in this coast and their seasonal occurrences. It will also catalogue the painful stingers.”
He further adds, “Some studies have shown that the jellyfish population is increasing in different parts of the ocean. It creates nuisances to fishery, coastal cage cultures, seawater intake systems. Tourists/bathers are getting painful stings due to jellyfishes. So, the ongoing research work will help in predicting their aggregations in the coastal water.”
A published study by NIO mentions that the extraction of Rhizostoma pulmo discarded off the Goa coast, India resulted in obtaining remarkably higher yield of 47 percent (based on lyophilized weight) type I collagen. The amino acid composition showed presence of glycine, hydroxyproline and proline and other amino acids in consistent with mammalian collagens. Interestingly, it also possessed essential amino acid tryptophan that makes this collagen superior than other commercially available collagen products.
Nester Fernandes, research and outreach officer of ReefWatch Marine Conservation, Goa loves observing the marine biodiversity along the Goan coast. However, as a personal hobby, he has been studying jellyfish and their pattern in Goa. “I am especially focusing on true and false jellyfish. Porpita porpita is a false jellyfish and like all jellyfish, they get washed ashore during the low tide. Even when there is rough water conditions, jellyfish cannot manoeuvre in the water like fish and land up on the shore. They usually get back to the water on high tide but if it is extreme heat, then they can dry up and die. I have been observing jellyfish for over a year along with a student from Chowgule College, Margao and we are working on a research paper. However, we still have a lot of study to do,” informs Nester.
During the pre-monsoon period, Nester traveled to 14 Goan beaches from north to south and found jellyfish watched ashore. “Olive Ridley sea turtle which is found in Goan waters eat jellyfishes. Hawksbill sea turtle eat jellyfishes but they are rarely stranded or spotted in Goan seas. Jellyfish eat fish and when the sea turtles eat jellyfishes, they are in turn controlling the jellyfish population and aiding fish population,” he explains.
President of Caranzalem Raponkar and Traditional Fisherman Association, Francisco Vaz has grown up by the seashore and finds jellyfish as a common visitor. “Jellyfish is a marine creature and it has been found in the waters of Goa for years. They are very dangerous and their stings can hurt very badly. The only quick remedy if one is stung by a jellyfish is to apply vinegar or salt or hot water. If it is extreme and the tentacles were near the face, then one has to immediately refer to a doctor. Once on a morning walk, I saw a foreigner whose four-year-old was stung by a jellyfish. The child was in excruciating pain and since she was small, I immediately called someone to get vinegar and rush to the beach. She had already developed boils on the part that was stung,” informs Francisco.
He further adds, “Sighting jellyfish on the beaches of Goa is not a new phenomenon. We have been seeing them for years and as they are sea creatures there is no way, they can be prevented from coming near the shoreline. They have been getting trapped in the fishing nets and at times, it gets so heavy to pull the nets that had to just leave it open in the sea. There would be very less fish when all the holes are blocked by the jellyfish. It is also quite risky for the swimmers of the National Games that are held at Miramar beach as the jellyfish are very close to the shore. With the retreating rains, if the jellyfish are even 4-5 nautical miles away, they reach the shore within an hour.”
The best way to celebrate World Jellyfish Day is to travel to the beaches of Goa with the hope of catching a glimpse of a jellyfish that is waiting to return to the water at high tide.
