At first, the serene water is only punctuated by a few of them. Then all of a sudden, more begin to rise into view, filling the formerly blue waters with hundreds of gelatinous white spots. These immense gatherings of medusa are known as “jellyfish blooms,” and they have become increasingly common in the past few decades.

Higher ocean temperatures typically pose a serious threat to most marine species, but jellyfish are largely unaffected by the warming waters. One reason for its resistance is the jellyfish’s structural simplicity—their bodies are composed of about 95% water and lack the intricate physical features that most other organisms possess. As a result, they are not susceptible to extrinsic factors such as acidity, salinity, light, and temperature. Furthermore, many of the predators that formerly kept jellyfish populations in check, like sea turtles and whale sharks, are in decline due to overfishing, pollution, and global warming.

While a small gathering of them may be harmless, too many jellyfish can have devastating consequences. In the past, jellyfish outbreaks have interfered with coal power plants, clogged fishing nets, and obstructed nuclear reactors. They also negatively impact other marine organisms—in 2007, for example, a jellyfish bloom off the coast of Ireland killed around 100,000 salmon. These organisms pose a serious threat to human beings as well. The sting of one species, the box jellyfish, can induce vomiting, an increase in blood pressure, and even heart failure.

However, it is important to note that not all jellyfish are harmful. The word “jellyfish” is actually an umbrella term that encompasses thousands of marine species, including siphonophores, hydromedusae, and comb jellies. All of these organisms have a crucial role to play in the Earth’s ecosystem. Dr. Angel Yanihara, a researcher at the University of Hawaii, reflects that the jellyfish blooms serve as a symbol for overfishing and climate change in several areas. “It’s a wake-up call by nature,” she remarks. Rather than antagonizing jellyfish, it is important to recognize that the real problem stems from global warming and anthropogenic impacts on the environment.

 

written by Keerthi Selvam

edited by Saanvi Gutta and Sarasi Rout 

 

Resources:

1. Lamb, J. (2017, March 31). The Global Jellyfish Crisis in Perspective. JSTOR Daily. https://daily.jstor.org/global-jellyfish-crisis-perspective/
2. Pohl, O. (2002, May 21). New Jellyfish Problem Means Jellyfish Are Not the Only Problem. The New York Times. https://www.nytimes.com/2002/05/21/science/new-jellyfish-problem-means-jellyfish-are-not-the-only-problem.html
3. Watch out for jellyfish blooms. (2020, December 27). NIWA. https://niwa.co.nz/news/watch-out-for-jellyfish-blooms
4. Woodward, A. (2019, October 31). Thousands of animals around the world are at risk of extinction. But not jellyfish — they’re thriving in warm, polluted water. Business Insider. https://www.businessinsider.com/jellyfish-thriving-climate-change-warm-oceans-2019-10?international=true&r=US&IR=T#for-one-they-prevent-swimmers-and-beachgoers-from-entering-the-water-some-150-million-jellyfish-stings-occur-annually-worldwide-11
5. Zielinski, S. (2014, May 16). Winds predict deadly jellyfish blooms. Science News. https://www.sciencenews.org/blog/wild-things/winds-predict-deadly-jellyfish-blooms