The majority of humans now live in cities. Some are the great cities, rich in history, filled with modern delights; others are less great cities, cities that never were much to talk about or cities that long ago lost their vitality. But all cities provide a layer of insulation between the individual and the natural world that sustains his/her life. When your food comes from the supermarket, your water from a tap, and your shelter from the efforts of specialists called construction workers, it is easy to forget that ultimately food, water and shelter are provided by nature.

Separated from nature it is also easy to become detached from nature, to fail to recognize the damage we do, day by day, to the natural systems that underlie our own lives. How else to explain the relative lack of urgency about an environmental crisis that grows steadily worse? Oh, we know about the environmental crisis, but we do not see it as the life-threatening monster it is. We do not fear it; we have lots of other concerns that are more important. Finding ways to break through to urban populations is a major task for those who would change our perceptions of the environmental damage we are creating.

One view of Tokyo. Photo: Shinichi Higashi. Creative Commons BY-NC-SA (cropped).

Our impacts on the planet are not uniform. There are still places lightly touched as well as places made virtually uninhabitable by our past activities. True, there are ever fewer lightly touched places, but the fact that some still exist gives hope that it is not yet too late for us to recover a world that we need if our lives are to continue to prosper. Our appreciation of places varies, and our understanding of how they are being changed also varies – we are simply more aware of certain types of ecosystem and can see more easily how our actions are disturbing them.

When it comes to the oceans, our ability to understand and appreciate is particularly weak. We simply do not know the oceans in the way in which we know the land. Reports appear regularly documenting the extent of our ocean impacts. We are changing ocean pH more rapidly and to a greater extent than it has been changed for 55 million years. We have initiated a process of sea level rise that is unprecedented during the last 8000 years, essentially all of human history, and it is going to disrupt all our coastal cities as well as our smaller coastal villages. It’s a process that will not stop for several hundred years no matter what steps we take to reduce emissions of greenhouse gases. Our warming of the oceans risks substantial changes to the pattern of global ocean circulation and a reordering of the planetary heat budget. The accumulation of plastic waste in the open ocean, never mind all the other forms of oceanic pollution, appears to be having substantive consequences for trophic structures of plankton communities as well as for unfortunate turtles, dolphins and other larger creatures which become inextricably tangled up or constipated and die unnecessary deaths. We have created some 400 coastal dead zones, regions of the ocean where nutrient enrichment, due to mismanaged agriculture and land use and to releases of inadequately treated sewage, both lowers fisheries production and leads to the massive toxic algal blooms that are red tides. And our overfishing, nearly everywhere, has reduced the total biomass of fish in the world’s oceans by 90%. Yet, mostly, we assume the oceans will endure.

The special case of coral reefs

Many of us can understand, and express concern for, the widespread clear cutting of tropical rainforests; not so loss of coral reefs. We know trees far better than we know corals. We recognize how rainforest loss can have serious consequences for weather, climate, biological productivity, global biodiversity and carbon sequestration, not to mention economic well-being of nations that have rainforests to harvest, but we are far less able to appreciate the consequences of coral reef loss. Coral reefs cover about 100 times less area than do rainforests, they are being lost at a far greater rate than are rainforests, and the suggestion that none will remain viable by mid-century is a dispassionate deduction from the available evidence by knowledgeable scientists rather than over-the-top hysteria by anxious greenies. Coral reefs are the most productive marine ecosystem by far and a vital storehouse of biodiversity, while playing a critical role in protecting nearby shores from the ravages of oceanic storms, and serving both as the larder and the employment bureau for many coastal communities. Many people have heard that climate change, overfishing, pollution and other factors are having serious consequences on coral reefs, and the notion that they are disappearing from the planet has been widely reported. Yet for most people this is just another unfortunate statistic, one of many to be tut-tutted about, but not something of real concern.

Photo: Saspotato. Creative Commons BY-NC-SA (cropped).

Yet think about this fact for a minute. Many coral reef scientists are convinced that there is only a remote chance that the world of mid-century will have any coral reefs resembling the reefs that were abundant as recently as the 1960s. Not fewer than now. None at all. In another 35 years. Yes, there will be living corals. Yes, there will be limestone reefs, slowly eroding away, with occasional colonies of coral growing on their surfaces. But there will not be any vigorously growing coral reefs, adding new limestone at rates that equal or exceed the rates at which reefs are eroded by storms, wave-action, and the rasping, crunching, drilling out, and dissolving away that takes place continuously on healthy reefs due to the actions of a diverse array of bio-eroders including fishes, worms, snails, sea urchins, and sponges.

We have nothing to compare this to. In human history we have caused the extinction of a great many species, but we have never yet achieved the elimination from the planet of an entire ecosystem. That is what we are doing to coral reefs. It is really too bad, isn’t it? Quite sad, really. Unfortunate. But not nearly as important as what Kim Kardashian did this morning!

Why we need to be able to talk underwater

And this is why I wish we could have underwater conversations. There is a big difference between knowing about the ocean, and knowing the ocean. You can learn about any natural environment from books, videos, Wikipedia, Google, and even by listening to other people who know about that environment when they reminisce. Rather than knowing about, you get to know a natural environment by becoming immersed in it. And you get to know it best, by being immersed in it in the company of other people who know more about it than you do. It’s a left brain, right brain thing. You learn about the natural world using your analytical mind; getting to know or even to love the natural world requires a different approach. Unfortunately, the ocean is hard to love, because we cannot have conversations beneath the waves.

Yes, I know there is technology that permits oral communication under water. Technology is available ranging from submarines and underwater telephone booths (called ‘talk bubbles’) to throat microphones, microphones built into the regulator mouthpiece, and bone conducting audio receivers. The technology has improved greatly over the years, but remains pricey, demands use of cumbersome full- or lower-face masks, and produces sound rich with the gurgles, bubbling, clicks and clanks that seem to happen when someone tries to speak under water. Darth Vader would find the sounds familiar; the rest of us, not so much.

The prices of the technology are high enough that the average sport diver never has the experience of talking under water. Instead, we use hand signals, short messages scrawled illegibly onto underwater slates, odd grunts and squeaks, and the rat-tat-tat of a convenient rock or other object against the scuba tank when it is really important to get someone’s attention. As a consequence, most dives are a solitary affair, even when one dives as part of a group.

Divers using a talk bubble, a rigid plastic hemisphere big enough for two, to have a short conversation. Photo: NOAA Photo Library, public domain.

Throughout the tropics there are dive shops affiliated with hotels that provide an opportunity for sport divers to explore the nearby reefs. The typical dive (there are brilliantly organized exceptions) begins with paying your money and checking out any rental gear you need. Then you assemble at the dive vessel, and take the short ride out to the destination.

The dive master and any associated staff introduce themselves, provide a one- or two-sentence description of where you are going and perhaps what you will see there. More time is (rightly) spent on safety aspects, including how long the dive will be and how deep, and where to aggregate at its conclusion. Then it is time to gear up and jump in. The group assembles at depth, OK signals are exchanged, and the dive leader sets off on his or her chosen path, followed by everyone else. Typically there will be a few stops at particular points of interest – perhaps the hang-out of a friendly moray, or a particularly fine coral formation or seascape. Sometimes these stops are really just an opportunity for the dive leader to do a count, ensure nobody has wandered off, check on the stragglers, and especially query each participant on the state of his or her air supply. Eventually, after a time that should be manageable by the most air-hungry member of the group, the dive leader brings you back to the rendezvous point, usually with a safety stop hanging off the anchor line, and back on board.

The post mortem period is spent taking off and stowing the gear, getting dry and warm if conditions have been chilly, and sharing some soft drinks or something more elaborate. Only rarely will the dive leader talk about what has been seen, although with prodding many are quite knowledgeable. Back on shore, you have enjoyed yourself, you are ready for the next item on your to-do list for that day, but you really have not added to your understanding of what you saw down below the surface. And if your background does not include the preliminaries of the natural sciences, you may not even know how to begin finding out about what you have seen.

Contrast this with a walk through a rainforest with someone who knows it well. Or a ramble along a rocky shore. Or, indeed, a hike in any natural environment on land. You’d be talking more or less continuously, and you would be learning. You’d discover that the creatures you might initially have been at a loss to describe have names, relationships, and patterns of life that are quite their own. You’d discover that creatures that look similar may or may not be closely related; that certain activities only occur in certain seasons or certain places, that some objects you did not even realize were alive are animals of particular kinds. And you’d learn about the relationships among all these creatures that occupy that particular landscape, about the ways in which the seasons affect their lives, and about how they affect each other.

Gaining all this knowledge will not force you to know and love that particular ecosystem, but without gaining all this knowledge it will be much more difficult, perhaps impossible to come to know it. It will remain the other. That is the problem for marine systems – they remain the other.

Over the years, I have come to understand that I have accumulated a lot of knowledge about my chosen undersea world, the reef, and my chosen creatures, the fishes. I know many people who have a far deeper well of such knowledge, but I also know I am more knowledgeable than most. When I put on my facemask, grab the regulator between my teeth and descend to a reef, I am entering a neighbourhood I know quite well. I recognize the inhabitants I expect to see there, and I know that they have complicated, busy lives; lives which, if I am careful, I will not interrupt too much.

I marvel at the complexity of their lives, the richness of their interactions both within and across species, the apparent orderliness of their day. I wonder how it is that prey species seem to be fully aware of whether a predator is hunting or just hanging out. I’ve learned to spot this same awareness when I am in the water with a microspear intent on ‘harvesting’ certain individuals for research! I wonder how the myriad species of reef fish recognize each other as fish, though clearly not their own species, and how they recognize the various crabs, snails and starfishes as alive. How do predatory groupers know that they should open their mouths and flare their operculae to allow a bite-sized cleaner wrasse to swim in and nibble away? How do they know to return regularly to a cleaner station to be ‘serviced’? Why do they not try feeding on other fishes aggregating at the cleaner station awaiting their turn to be cleaned? I confess to even wondering sometimes what a goby is thinking while it rests on the bottom, winnowing a mouthful of sand to extract the micro crustaceans while letting the sand grains fall out through its gills? Are gobies particularly contemplative fishes? Never mind what it is thinking about, how does it even manage to take a mouthful of sand and swirl it about in its mouth retrieving and swallowing the micro crustaceans while discarding the sand?

These are perhaps not the thoughts a scientist should have while collecting field data, but they are my thoughts, and wondering about these things is what makes a reef real to me. If only I could convey just a few of these crazy thoughts to other divers while on a dive.

The fact is that we are having profound impacts on the ocean, and these impacts are affecting the lives of the various species that live there in diverse, often rather bad ways. We care relatively little for the damage we are doing because we do not know the creatures that are being impacted. If we did, maybe we would rate our damage to the ocean as the globally serious problem it is. If we loved the ocean more, maybe we would take much better care of it.

This post first appeared on Professor Sale’s blog and is reproduced here with permission.