Dear jelly readers,
“Jellyfish taking over the seas” is typical of the headlines used by the media when reporting about jellyfish. But are jellies really becoming more common in our coastal waters? More and more people enjoy spending time out on the water hence people are encountering jellies more often. So are increases in jelly populations real, or is this apparent phenomenon just a biased perception? Answering this question is difficult because jelly populations fluctuate enormously – some years they seem to be everywhere, but at other times they’re impossible to find. To answer the question of whether jelly populations are increasing, therefore, we need data collected over very long periods of time.
Unfortunately for scientists, long-term data sets on jellies are very rare. However, there may be valuable records of jellies, which could help us answer this question, that may be tucked away in archives and not known about by scientists. For example, community groups that care for beaches may have kept notes each time they noticed jellyfish being washed ashore. Power stations and other coastal industries that draw cooling water from the sea may have records of every time jellies have clogged their intakes. If you know of any long-term records of jellies, please let us know! Such information could be extremely useful in helping the scientists to work out, once and for all, whether jellies really are “taking over the seas”.
-- Dr. Kylie Pitt, Griffith University, Australia