Rhizostomes as a resource: The expanding exploitation of jellyfish by humans

While jellyfish are often considered to be a nuisance, their value to ecosystems and for human exploitation is shifting this perception. People have been eating jellyfish for millennia. In recent decades, the scale of jellyfish fisheries has expanded dramatically, with annual catches in the hundreds of thousands of tonnes. The overwhelming majority of jellyfish species targeted for human consumption are from the order Rhizostomeae, which can also be fed to livestock and certain species in mariculture operations. The use of rhizostome jellyfish is expanding beyond food applications, such as pharmaceuticals and cosmetics, especially for collagen and other bioactive compounds. Jellyfish collagen is high in antioxidants, can act as an immunostimulator, and has applications for tissue engineering and medical implements. Jellyfish venom extracts exhibit high biological activities, including those that are antihypertensive, antimicrobial, and anticancer. Jellyfish can also be used as fertilizers and insecticides, and jellyfish mucus appears to have potential as a filter for nanoparticles and microplastics, suggesting possible applications in wastewater treatment. Most of these applications are still in developmental stages, and beyond their use as food, jellyfish are not targeted at commercial scale, apart from collagen extraction. As research advances, exploitation of jellyfish is expected to continue expanding. Given the lack of knowledge and understanding regarding jellyfish fisheries and their management, caution should be exhibited to avoid overfishing.