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article imageThe payoff for overfishing- Jellyfish rule the waves

By Paul Wallis     Jun 8, 2009 in Environment
The decades of drift nets, long lines and ocean abuse are coming home to roost. The ocean food chain is coming unstuck to the point that jellyfish populations, free from fish predators, are exploding. Some of these things are giants, up to 200kg.
Recent Australian research by the University of Queensland and Australia’s peak science body, the CSIRO, has discovered that global jellyfish populations are literally inverting the marine ecology, from the Black Sea to South East Asia. Some idea of the scale of the problem can be seen from this image of giant jellyfish where a few of them are taking up more space than a fishing vessel.
In what the UQ calls a “jellyfish joyride” this change in ocean ecology is a potential disaster for fish populations, too. Many jellyfish are themselves predators on small fish, and they could decimate new spawning populations with ease. The jellyfish are capable of producing gigantic swarms, some of which are even able to move out of their natural habitat, and devastate salmon farms, as we reported a while back on DJ.
Other revelations, like the “immortality” of jellyfish, (as reported by DJ’s Chris V Thangham mean they can reproduce to an almost infinite degree, even from relatively small populations, let alone huge swarms. These guys revert to a juvenile form after reproduction, so it means the survey stats on populations could have been quite misleading, for decades, if “juveniles” were post reproductive forms. The ocean ecology could hit a tipping point very rapidly. (I’m assuming all this wasn’t your idea, Chris…)
In the ancient oceans, jellyfish were the dominant form of marine life for millions of years. The balance changed, gradually, as fish populations took over, but they’re still the original great survivors in the oceans. They’ve outlasted three major extinction events, and the arrival of Homo Sap. This could be one of the few cases of an ecological reversal ever documented.
Warmer ocean currents are also extending the range of many species of jellyfish, as delicately suggested by the presence of huge swarms of Mediterranean jellyfish in the North Atlantic, where they theoretically should have died of the environmental change.
(Presumably swarms of billions of invasive jellyfish, doing millions of pounds’ worth of damage are also the hallucinations of environmentalists. Ah well, the threat of relevance hangs over us all, doesn’t it?)
Now, the problem:
The solution, as usual, is basically a version of the same one marine biologists have been demanding for decades: To actively control the oceans, stop the overfishing, reintroduce working populations of jellyfish predators at all levels (small fish, like bait fish, turtles, and many type of juvenile fish, also eat young jellyfish, helping cut down reproductive numbers) and get it right for once about ocean management.
The fact, also as usual, is that the near total destruction of the fish populations, and systematic destruction of one of the world’s main sources of protein has been handled by the much too usual class of “Duhhhh…” political and administrative mentality we’ve all come to despise so enthusiastically for the last five decades or so. The total destruction of commercial fish stocks, as described in the Scottish salmon farm story, didn’t get much of a twitch out of any public authorities, even in relatively eco-friendly Europe. There is absolutely zero indication of any actual, enforceable, international management plan, real, theoretical, or ideological, to deal with the marine holocaust we've been seeing in recent years.
Add swarms of a type of animal which can reproduce and spread at almost bacterial rates, and you have a recipe for a real disaster.
Ocean administration at all levels has yet to produce the slightest hint of any form of actual success in either control of marine ecological disasters, overfishing, or anything else. Ecological controls are operating like fire brigades, after the events. Even controlling contaminated ballast water is a pretty inexact science, to describe it kindly. Exactly what the world is going to do with a sudden shortage of 30% of its protein supply, and a crash of a large part of the food industry, will be interesting to see.
I’m just waiting for the standard response: Do a documentary, get some clown to stick his face in front of a camera saying, “The jellyfish are coming! Be alert!” and everything will be fine. It's these bottomless standards of information, where even global disasters are mere media events, which have been the anesthetic masking the death of the fishing industry, and the oceans as we know them. Humanity is in the process of scoring an own goal of unbelievable dimensions here.
One day, environmentalism will be defined by effective action and results, not rhetoric and press releases. Let's hope it's soon, particularly in this case, or the only fish around will be in museums.
Meanwhile, I'm taking bets on this:
2/1 Nothing happens, five years from now, same problem, but more advanced, is "news".
1-1 Great interest produces years of deep study, followed by nothing happening.
5/1 Unsuspected sanity in global fisheries administration causes flicker of interest from governments.
10/1 Somebody in a position to get something done learns to read and understand marine biological reports.
50/1 Uncharacteristic outbreak of sanity among fishing nations, concerted efforts made.
100/1 Complete departure from script, effective controls designed and implemented in the course of living memory.
1000/1 Prompt, efficient, local and global response.
If anyone sees Doctor Pangloss, I don't take IOUs, but will consider autographed copy of Candide.
More about Jellyfish populations, Ocean ecology impact, Australian research
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