Jellyfish bloom
A temporary increase in jellyfish abundance within a marine area. Blooms can disrupt ecosystems, fisheries, aquaculture, and coastal infrastructure.
Jellyfish life cycle: The sequence of developmental stages through which jellyfish reproduce and grow, often including a polyp stage and a free-swimming medusa. Asexual reproduction by attached polyps can rapidly supply medusae when conditions favor their release.
Nomura's jellyfish: A giant scyphozoan jellyfish native to waters around China, Japan, and Korea. Its episodic blooms can damage fishing gear and reduce catches in the East Asian seas.
Fisheries: The harvesting of wild aquatic organisms for food, trade, or other uses. Jellyfish can clog nets, damage catches, and compete with fish for prey.
Marine food web: A network of feeding relationships among organisms in a marine ecosystem. Blooms can redirect energy flows by consuming plankton and becoming food for predators.
Jellyfish population trends: Long-term changes in jellyfish abundance, distribution, and frequency across marine environments. Global records show mixed regional patterns, leaving the scale of any broad increase unresolved.
Strobilation: A form of asexual reproduction in which a scyphozoan polyp divides into stacked disks that develop into young medusae. It can release many young jellyfish from polyps in a short period.
Aurelia aurita: A widespread moon jelly species found in coastal waters across much of the world. Seasonal aggregations of this familiar coastal jelly illustrate recurring local blooms.
Aquaculture: The farming of aquatic organisms in controlled freshwater or marine environments. Dense jellyfish can clog intake screens, sting cultured animals, or damage fish in net pens.
Eutrophication: The enrichment of water with nutrients that can increase algal growth and alter aquatic ecosystems. Nutrient enrichment may favor jellyfish indirectly by changing prey availability and reducing competitors.
Marine biodiversity monitoring: The repeated observation of marine species and ecosystems to track their condition and change over time. Inconsistent monitoring makes it difficult to distinguish new bloom trends from improved reporting.