“Jellyfish are taking over the seas, and it might be too late to stop them.” (Guilford, 2013).
“Jellyfish population boom wreaking havoc worldwide.” (Cho, 2014).
“Are jellyfish going to take over the oceans?” (Mathiesen, 2015).
There have been a mind-boggling amount of environmental issues over the last few decades, but never before did I imagine that jellies would be the cause of so many problems and so many dramatic headlines.
To catch you up, massive jelly blooms have been spotted throughout the oceans. Worse than simply being spotted – jellies have been the cause of a variety of issues, from costing fisheries thousands of dollars to clogging nuclear reactor cooling water intakes (Guilford, 2013). Studies show that this burst of jellies could be due to a decrease in ocean water quality; temperature changes, acidity, and other factors could be linked to jelly populations thriving (Qu et al., 2014). Many are tempted to equate the success of the jellies to climate change, and while this could very well be the case, it’s too soon to jump to that conclusion.
According to Qu et al. (2014), jellies have physiological characteristics that allow them to better survive in harsh environments. These characteristics include simple body structure, rapid growth, short generation time, and quick, bountiful reproduction. When the ocean environment is unable to support as many other organisms, the jellies are quick to fill that gap. Stone (2011) states that overfishing and worsening ocean water quality are the “chief suspects” in ecological gaps that the jellies take over.
Their impacts are numerous and frightening – clogging nuclear cooling water intakes, capsizing trawling vessels, killing salmon in fishery operations, stinging humans. Though death by jelly sting is not often talked about in comparison to shark attacks, more humans die each year from lethal jelly stings than by shark attack (Stone, 2011). And if we weren’t already concerned, warming oceans will likely expand the ranges of deadly jellies towards the poles.
While the jellies slowly creep poleward, us humans fret and bite our nails, convinced this must be yet another side-effect of our presence on earth. Indeed there are signs that could point towards the cause being climate change, but we cannot say for sure. Most jelly data collections and surveys have only been in progress for the past decade or so. An example of one such survey is through the UK Marine Conservation Society, who’s survey has only run for the past 12 years (Mathiesen, 2015). This time frame is only enough to tell us that there is an upward trend, and not much more yet.
The answer lies within the data, so for now, the unsatisfactory answer is: more data!
To help out, you can report jelly bloom sightings on websites such as JellyWatch.
Cho, C. (2014). Jellyfish population boom wreaking havoc worldwide. CBC News. Retrieved from http://www.cbc.ca/news/canada/british-columbia/jellyfish-population-boom-wreaking-havoc-worldwide-1.2698699
Furuya, S. (2015). World worries as jellyfish swarms swell. Nikkei Asian Review. Retrieved from http://asia.nikkei.com/magazine/20150205-Changes-in-the-air/Tech-Science/World-worries-as-jellyfish-swarms-swell
Guilford, G. (2013). Jellyfish are taking over the seas, and it might be too late to stop them. Quartz. Retrieved from https://qz.com/133251/jellyfish-are-taking-over-the-seas-and-it-might-be-too-late-to-stop-them/
Mathiesen, K. (2015). Are jellyfish going to take over the oceans? The Guardian. Retrieved from https://www.theguardian.com/environment/2015/aug/21/are-jellyfish-going-to-take-over-oceans
Qu, C.F., Song, J.M., & Li, N. (2014). Causes of jellyfish blooms and their influence on marine environment. Pub Med 25: 3701-3712.