close you can actually see some scars from the surgery.”
Van Bonn steps closer to the glass of the aquarium. The ray makes a slow motion underwater back flip with her cape-like fins. Van Bonn eyes her with a winsome smile. Nothing like the satisfaction of a surgeon in the presence of a fully-recovered patient.
I’d come to interview Van Bonn because he was heading up the Shedd Aquarium Microbiome Project, which studies microbiomes in aquarium environments and their impact on the inhabitants of those habitats.
“If you break the word microbiome down,” Van Bonn explains, “micro means tiny, bio means living, and ome means community. We’re talking about microscopic living communities.”
We know microrganisms dramatically affect human health. Probiotics may ease indigestion after taking antibiotics, which sometimes kill off not only the harmful bacteria in our bodies, but the ones that help us digest food too. Each of our bodies is quite literally an ecosystem supported by communities of organisms—in our GI tracts, ears, skin, and saliva—many of which are essential to good health. Most of us are more aware of the consequences of an imbalance in the ecosystem of our body, such as antibiotic-resistant bacteria that can kill us.
But why study aquatic microbiomes?
Same thing. The upset of microbial communities—lack of balance—is having devastating effects on our seas and waterways. Aquatic dead zone, caused primarily by fertilizer runoff, are areas in which there is such a low oxygen concentration that many organisms suffocate and die. These dead zones are expanding. The largest one in the Gulf of Mexico is 8,500 square miles, roughly the size of the state of New Jersey. And not only does this have consequences for the fish that breathe water, it has consequences for our atmosphere: over half the oxygen in every breath we take comes from marine microbes, plants and algae.
Toxic algae blooms are another result of microbiome imbalances. The algae bloom that currently stretches from southern California to the Alaska has triggered fisheries closures. The toxin, domoic acid, causes amnesiac shellfish poisoning in human beings. The chilling list of symptoms leaves no doubt that fisheries should be closed when it’s a threat—seizures, brain damage, and memory loss. The toxin is responsible for the deaths of thousands of marine mammals and sea birds.
Minimizing pollution and mitigating climate change are key solutions. But understanding the mechanisms of those imbalances, so we can help restore healthy aquatic microbial communities is also key. So what is a balanced aquatic ecosystem? What is healthy water?
The answer is undergoing re-definition and that’s what the Microbiome Project’s work is all about. “Healthy water” had traditionally meant “sterilized” water, devoid of germs. Now we are learning that healthy water entails a balanced microbiome of organisms. But what exactly do those balanced microbiomes look like? That’s the focus of the research and it will shed light on everything from marine ecosystems, lakes and waterways to water treatment facilities.
Van Bonn leads me out a side door to a large covered outdoor pool surrounded by visitors—a touch pool. A dozen or so cownose rays swim through the shallow water like a flock of aquatic birds. The visitors rinse their hands to protect the health of the rays, roll up their sleeves and gently lower their hands into the pool. When a ray comes and touches them, they squeal with delight.
“I like to think of the earth as aquarium earth,” Van Bonn explains. “There’s no doubt, our planet is a controlled environment.” Van Bonn is referring to the fact our planet has only so much water and other resources to offer. By virtue of humanity’s vastly expanded influence, we need to be stewards of those resources.
“Aquariums are great test platforms to study the impact of human activity on aquatic
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