Jellyfish blooms and our changing ocean

Signs that our ocean is sick:

1) Its color is off

2) It throws up garbage on our shore

3) The fish are looking for new real estate

4) The meek are inheriting the ocean.

Screen shot 2013-04-09 at 9.40.34 PM

I guess I wouldn’t exactly classify jellyfish as meek, but they aren’t at the top of the food chain.  But,  there are population blooms happening all over the ocean.

Jellyfish thrive in warmer, less oxygenated water.  Rising global ocean temperatures encourage jellyfish blooms, and increasing jellyfish populations encourage increasing jellyfish populations,  tipping the balance in their favor.

It is  easy to see the ocean as tough and impenetrable, when it is actually quite delicate.  Each organism serves a function and has a weight on the scale that keeps a precise  balance.  When one group begins to grow, the balance is disrupted.  This disruption sends things spiraling into the unknown.

Krill populations have been declining exponentially for decades.  Animals that rely on krill (penguins, whales, birds) start declining in number.  Jellyfish food has jumped into the void left by krill, encouraging jellyfish to eat more and reproduce more.  And jellyfish can eat up to 10x their weight per day. even though they only need to eat up to 16% of their weight per day.  They also compete with fish for food….and then eat  those fish’s eggs as well, which starves populations, and prevents them from reproducing.

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Also, humans have given ample space for jellyfish to reproduce:

They’re world-class proliferators. Jellyfish don’t have baby versions of themselves the way most animals do. They create polyps—little bundles of clones—that attach to hard surfaces and wait for their opportunity to release small jellyfish. However, while they’re waiting, polyps clone themselves, creating more bundles of future baby jellyfish.” –Guilford, “Attack of the Blob

We have increased the flat surfaces that polyps  attach to,  by building structures underwater, and dumping massive amounts of trash.

Another factor in the rising jellyfish population are “dead zones”, which just sound like bad news. Eutrophication (sewage, farming runoff, etc) that cause algae blooms that jellyfish (and others) just go cuckoo for. They gorge themselves on food and reproduce like crazy.

So what do rising numbers of jellyfish mean? For one, they are clogging cooling systems of nuclear reactors.  For another, they are stepping on the toes of tourist popular swim areas.  For a third, they are decimating fish populations rapidly, and there’s even an instance of a Japanese ten ton trawler that capsized trying to haul in their nets, that happened to be filled with refrigerator sized Nomura. (This hug nomura population are a product of an algae bloom from where the Yangtze river meets the sea).

Giant Jellyfish, Nemopilema nomurai, clogging fishing nets in Japan. (Dr. Shin-ichi Uye)
Giant Jellyfish, Nemopilema nomurai, clogging fishing nets in Japan. (Dr. Shin-ichi Uye)

What do we do to counteract this bloom? Honestly, it may be too late, as it is almost impossible to fight a jellyfish bloom. Jellyfish have few natural predators, and definitely not enough to counteract the increasing numbers, and when jellyfish are introduced to new ecosystems, they often have NO natural predators.

Perhaps, this is an instance of lying in the bed we’ve made. Overfishing, pollution, and run off have tipped the balance  in favor of the jelly, a creature without a brain, a creature composed mostly of water, a creature that does not act on impulse (is it irony, that our thoughtless actions have paved the way for brainless organisms to take over?)

pretty yes, but not a thought in sight.
pretty yes, but not a thought in sight.

With each change in the world that we bring, we must attempt to prevent further damage.  Some would say that this is a lost cause.   But I disagree.

In the case of the jellies, we must learn, adapt, and slow the possible future growths, and be watchful for upcoming changes in the balance. Sometimes it can helpful just to be observant to the changes as they occur.


Check out this website:

“Stung! On Jellyfish Blooms and the Future of the Ocean.” by Lisa-Ann Gershwin.  read it and find out more about how our sick ocean is changing .

And this: an EXCELLENT break down on Lisa-Ann Gershwin’s excellent book, for those who don’t feel scientifically inclined, with really great graphics.

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