GLOBAL SWARMING

JELLYFISH USED TO DRIFT under most people’s radars. But in recent years they’ve become hard to ignore, with reports of increasing jellyfish ‘swarms’ along coastlines and in harbours. These events are more accurately known as jellyfish blooms and are a natural stage in the population life cycles of these mysterious, diaphanous creatures that invoke both revulsion and fascination. But there’s concern about the increasing frequency and size of such events, with some blooms thought to be indicators of ecological disturbance caused by anthropogenic factors such as pollution and overfishing.

Leading international jellyfish researcher Dr Kylie Pitt, a professor in marine ecology at the school of Environment and Science at Griffith University, Queensland, has, for the past decade, been investigating reasons for these explosions of gelatinous marine life. Most recently she headed a review by an international team of scientists looking into the role played by human impact, the results of which were published in the journal Frontiers in Marine Science in late 2018. Although this has the potential to enhance jellyfish blooms, the review found little proof this was already happening on a grand scale. There are a few problem species, but jellyfish certainly aren’t taking over our waters as some media reports have suggested.

What this and similar research has exposed, however, is a far bigger problem: at a time when many of the world’s marine habitats face unprecedented environmental threats, very little is known or understood about one of the oldest and most pervasive animal groups in our oceans. “As a community we need to qualify the statements we make about jellyfish to strike a better balance between what we think we know and