A review of jellyfish aggregations, focusing on India’s coastal waters

A review of jellyfish aggregations focused on India’s coastal waters was conducted, with the aim to enhance understanding of conducive conditions and subsequent ecological impacts. Jellyfish swarming, as well as their beach strandings, have been reported from many areas of the world—including India’s coastal waters. A variety of natural (winds, tidal fronts, surface currents, water temperature, salinity, turbidity, dissolved oxygen) and anthropogenic (water quality deterioration, overfishing, translocation, habitat modification) factors play pivotal roles in triggering jellyfish aggregations. Jellyfish aggregation events in the forms of their swarming in coastal waters and beach strandings have resulted in ephemeral nuisances such as water quality deterioration, food chain alterations, hindrance in seawater uptake by power plants, clogging of nets during fishing operations, and tourism declines. Several well-known Indian tourist beaches (e.g., Puri, Chennai, Goa, and Mumbai) have experienced beach strandings. Despite recurrence of such events, jellyfishes are relatively less scientifically investigated and monitored in Indian coastal waters. Therefore, it is important to determine the environmental conditions that trigger jellyfish swarming, in order to develop effective monitoring and prediction strategies. This study additionally proposes a conceptual framework towards development of a jellyfish monitoring system for Indian waters using satellite and model data.