HATTIESBURG, MS (WDAM) - This is a news release from the University of Southern Mississippi
Jellyfish, long regarded as the pests of the sea, may play an ever-larger role in defining the relationship between humans and the world's oceans, according to a new paper published in Frontiers in Ecology and the Environment.
If jellyfish populations rise, the negative consequences may render vital fishing, power generation and desalinization operations increasingly difficult in some parts of the world.
In the paper, “Linking human well-being and jellyfish: ecosystem services, impacts, and societal responses,” an international consortium of scientists led by Monty Graham, chairman of the Department of Marine Science at The University of Southern Mississippi, calls for a new global emphasis on studying the various gelatinous creatures commonly referred to as jellyfish.
Despite jellyfish blooms that close beaches, disrupt fisheries, and shutdown power plants, aquaculture facilities and water treatment systems around the globe each year, scientific studies of jellyfish remain rare.
“We still don't have a good understanding of what controls jellyfish populations and we know very little about a key part of their life cycle: polyps, especially in the field. We could rapidly expand our knowledge with some very basic experiments and research,” said Lucas Brotz, Sea Around Us Project, Fisheries Centre, University of British Columbia. “We're learning that jellyfish are not dead-ends in the food web as was previously thought.”
In fact, jellyfish, particularly the delicate, spiraling creatures known as salps, have been revealed as an exceptionally efficient mechanism for moving carbon from the surface to the deep sea. Other jellies are an important food source for humans, while some are critical to new high tech medical techniques, or have applications in the pharmaceutical and cosmetic industries.
“Jellyfish are a normal part of the ecosystem, and there are quite a few ‘good' things they provide for humans. They often get mislabeled as ‘pests', so understanding how impactful they are depends on how their positive aspects are weighed against the negative ones,” Graham said. “By comparing the good against the bad, we believe an ocean that favors more jellyfish will be far more harmful than the services those jellyfish would provide.”
A central question among the scientists is whether various jellyfish populations around the world are increasing, and if overfishing of other marine species plays a role in promoting jellyfish. There is no easy answer, but the implications of a possible increase in jellyfish are worrisome.
“It would appear that many overfished ecosystems are showing increasing jellyfish populations. Because fish are predators and competitors of jellies, removing too many can allow jellies to thrive,” Brotz said. “Even if the overfishing impact is subsequently removed, jellyfish may continue to dominate by preying directly on fish eggs and larvae. As overfishing impacts often occur simultaneously with pollution and coastal development, we need to better understand the impacts of our activities in the context of warmer and more acidic oceans. Lots to do.”
Despite being dismissed as a nuisance for centuries, jellyfish populations have the potential to affect long-term human well-being, concludes the paper, which was funded by the National Science Foundation through the National Center for Ecological Analysis and Synthesis at the University of California at Santa Barbara.
The scientists call for comprehensive study of issues that may influence jellyfish populations in the future, including overfishing, low oxygen dead zones, invasive species introduction and climate change.
To receive a copy of the paper, please contact Dr. Monty Graham at