A prescription for the ocean’s ailing health

Twenty years ago when I had the opportunity to dive to 18,000 feet in the Japanese research submersible “Shinkai 6500” in the Sea of Japan.

I fantasized about the amazing animals our team might see deep on the ocean floor: rat-tails, deep sea sharks, and octopi.

But when we reached the sea bottom, it was littered with trash that included food bags, soda cans, empty boxes, and even a broken toy doll. I shudder to imagine what that same sea bottom looks like today.

The ocean is a beautiful, mystical world that covers more than 70 percent of our planet and supports a mind-bending array of life below the surface and above.

But it’s also a fragile ecosystem that is vulnerable to the strains placed upon it, which include pollution, increased acidification, and the warming of the water, all of which can harm the life supported by the oceans.

Some of this strain is visible, but much of it not. The ocean hides most of what we do to it. But I can tell you first-hand that it is facing a health crisis that needs urgent care.

Because most plastic floats, we can see it accumulated along shorelines, on beaches and lately, in ocean gyres hundreds of miles across (large circular closed-current systems — there are 5 worldwide).

And because most Laysan albatrosses nest in protected and well-studied reserves in the Hawaiian Islands, we’ve seen the frightening accumulations of plastic objects that parents and chicks ingest, and the terrible toll that takes.

I was at one such reserve in Mid-Way Island last June and saw this fist hand. Every few feet, everywhere on the island were pieces of plastic brought there by albatrosses because they confuse the plastic for food. I saw one mother trying to feed an old toothbrush to her chick.

Less visible are the effects of plastic ingested by marine turtles that mistake plastic bags for their jellyfish prey and choke to death or die of intestinal blockage.

Completely invisible are the effects of tiny particles (microplastics) released when larger chunks of plastic slowly degrade at sea and enter food chains.

We have little idea of the extent to which these particles block or damage the digestive systems of zooplankton and larval fish, or the effects of oil, PCBs, and pesticides, which accumulate on the particles’ surfaces.

In all these ways, plastics typify the major plot line for most of our abuse of the ocean: wonderful new products or techniques are ingeniously developed, deployed to excess, and thoughtlessly abandoned after use with unpredicted and unregulated disregard for side effects that harm the environment and marine life.

It’s this that has also led to expanding “dead zones” (large areas of low oxygen water such as those found in the Gulf of Mexico), climate change, sea level rise, ocean acidification, overfishing, loss of biodiversity, and increasing frequency of invasive species.

All of these threats to our oceans and planet have traceable sources and both visible and invisible effects. Today, the relentless spread of these stresses has reached global scale. A study in 2008 published in “Science” led by B.S. Halpern showed that no area of the ocean is unaffected and 41 percent is strongly affected by multiple human activities.

The comparatively small 4 percent of ocean which scored as “very lightly impacted” was located near the poles, where seasonal or permanent ice cover has reduced human access. Those areas will see increased impact as ice cover recedes because of global warming.

So the bad news is that the ocean and many of its habitats and populations are approaching a state of crisis. But the good news is that they aren’t dead yet. Also we understand the nature and extent of the worst problems and we know what solutions will bring the ocean back to good health.