A Sea of Glass Page 4
While there is agreement that coral reefs worldwide are highly endangered by climate warming and ocean acidification, there is much speculation about the details of what will happen. For example, some ask whether coral species will escape the threat of heat stress by moving to cooler waters (Precht and Aronson 2004). Certainly this is what we have witnessed in the fossil record as a response to climate change. Others argue that adaptation and evolutionary change will slow the pace of this catastrophe (Palumbi et al. 2014). But this increase in carbon dioxide–driven warming and acidity is vastly more rapid than ever experienced. If the amount of carbon dioxide in the atmosphere is not curbed, within fifty years the oceans will become so corrosive that most species will not be able to calcify. We know this because in laboratory experiments, coral colonies grown in corrosive, low-pH conditions actually survive, but they dissociate from a calcified colony into a non-calcified collection of anemones, in what seems like a bizarre parody of the evolutionary process that produced corals from the more ancient anemones in the first place. A few tough, starling-like species that can tolerate both heat stress and acidic waters will persist, as we have observed in natural carbon dioxide seeps near Papua New Guinea. This is not a coral reef and will not house the tremendous biodiversity and fishery riches that a healthy reef supports (Sale 2012).
Orange cup coral (Astroides calycularis) in glass. This nocturnal coral does not have photosynthetic algae. It is currently listed as endangered in the Mediterranean, but we saw some on a dive at Portofino, Italy. Photo by Elizabeth R. Brill.
So how do the Blaschkas and their fragile glass models figure here? Because so many of their living counterparts depend on coral reefs for habitat, my trips around the world to document their well-being naturally include forays into fragile reef territory. Coral reefs are the backdrop to the kaleidoscope of colorful and unique creatures I have set out to find, including the anemones. It’s ironic that of all the invertebrates on my list, anemones are the closest relatives to the corals and yet we know very little about them in terms of extinction risk.
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After years of cataloguing ecological disaster on the biodiverse reefs of the tropics, it was a relief to venture into old, familiar waters near my home in the San Juan Islands; these marine ecosystems haven’t experienced some of the ravages of climate change and are still vibrant and healthy. On this dive, David and I were looking for the living counterpart of one of the Blaschkas’ more stunning glass models. Leopold’s models of the plumose (Metridium senile) anemones, shown in the Dublin Natural History Museum packed tentacle by mouth into a single bank of white and beige, are just like the living anemones on deep rock walls in the San Juan Islands. They are of particular interest to us because Leopold Blaschka made a special request to have a live collection sent from Kiel, Germany, in 1880, which he planned to keep in his aquarium. As with so many of our Blaschka invertebrates, the species name has changed. Leopold asks for Actinoloba dianthus, which is now named Metridium senile. He also reveals in his letter the method of successful shipping: animals were packed moist, but without seawater, in marine algae and sent through the mail. An excerpt of his request to a Mr. Handtke in Kiel, circa July 1880, follows. It includes mention of the Christmas anemone, Tealia crassicornis, now named Urticina crassicornis and also abundant in Friday Harbor.
Then I request you, to send me when it is possible for you an amount of fresh plumose anemones (Actinoloba dianthus). These may be big or small, of various colour, whatever it is possible, and I prefer it the most, when they still find themselves on the very same substrates as where they were found on. I would love it, if you would try to send me by mail a number of Actinoloba, dry, I mean with no water, only wrapped in moist algae and packed in a can or in a keg. If possible, please add a few of Tealia crassicornis as well. (Reiling 2007)
Our very first dive to seek out Blaschka lookalikes was a daytime dive to see if we could still find these deep banks of the plumose anemone in the dark, cold waters of the Pacific Northwest. Given that it’s in my own backyard, it was a natural first start. In addition, these are some of the richest waters off the continental United States, with a high number of the kinds of soft-bodied animals that the Blaschkas created: anemones, nudibranchs, worms, and sea cucumbers. The only issue was that I’m no longer so fond of diving in rugged, icy seas, and it requires a lot of stiff, heavy gear. In fact, I hadn’t done a cold-water dive in decades. In making the transition to working in the warm, clear waters of the tropics, I had left behind my graduate school plunges into these dark, current-driven waters. It had been almost thirty years since I’d last visited this area. The tantalizing allure of seeing the anemone-encrusted rock walls again—and reassuring myself that they were still thriving—convinced me it was worth doing.
As David and I arrived at the site called Shady Cove, little more than a notch in the steep, rocky shore, I considered the dark dihedral rock that led sharply down to the enormous underwater cliff that lay fifty feet below the surface. The hope was that the overhang would hold back some of the lush kelp growth and permit us to find the giant plumose anemone (Metridium farcimen, formerly M. senile). Although it covers the undersides of many docks and pilings, we wanted to find it in a more natural habitat, framing the rich biodiversity of our deep underwater cliffs. As we suited up, I eyed the dark water swirling around us. The Pacific Northwest has some of the more dangerous diving conditions to be found anywhere, including very cold water and currents so strong we could only safely dive on the exact slack of the tide, which is the one thirty-to-sixty-minute point during each day when the tide is neither rising or falling. Unfortunately for us, because it was a full moon, the slack tide was short and would change fast, on top of which Shady Cove is known for fast and unpredictable tide changes. In long-ago dives here, we had surfaced to currents so strong it felt like being in a river. As I contemplated the moving water, our boat captain reminded us that we’d only have about thirty minutes before the tide turned, so it was now or never.
My unwillingness to get in the water was tempered by the certainty that a high current would make it harder to stay in one site and find our anemones and nudibranchs. I grabbed my flashlight and decided to leave the camera behind, grinned at David, my co-conspirator in this endeavor, and went over the side. My wetsuit was thick, tight, and stiff, but it did a good job of slowing the icy trickle of cold water into the suit. It was hard to swim on the surface, weighed down by all the rubber and gear, so I signaled to David that I was going down. As I slowly sank away from the lighted surface, I swam toward the wall. With surprise and a growing uneasiness, I realized that the cold was not nearly as much a problem as the dark. It was the height of the summer plankton bloom and the light was so quickly attenuated that within twenty feet it was completely, disorientingly dark. I couldn’t see David, I couldn’t see the bottom, I couldn’t see the wall, and I could barely see the surface. I was breathing too fast, and my suit was too tight and confining. My panic grew at a rate almost too fast to control. I grabbed for my rented gauge and realized the tiny numbers were too small for me to read easily, so I didn’t even know my depth, and the borrowed light was tricky to turn on. I worked to calm myself: Slow your breathing, find the wall, adjust your buoyancy and breathe . . . move slowly, look at something under the kelp. It worked; I didn’t bolt for the surface. I looked at David, and out of habit only I gave him a grin and a thumbs-up, but it was enough to refocus and follow my training, adjust my buoyancy, take a slow breath, and proceed down. In thirty years of diving, this was the first time I had almost aborted a dive. I was still not happy, but I was excited to see my old invertebrate friends on the rock wall that had been the site of my very first underwater job.
As an undergraduate, I worked for an invertebrate paleontologist who was researching the question of whether mussels had contributed to mass extinctions of brachiopods, a non-mollusc bivalve that created vast fossil reefs, by climbing over and smothering them. Shady Cove has a fantastic population of th
e smiling brachiopod at diving depths, so it was a good site to do experiments. I helped Charlie Thayer, then at the University of Pennsylvania, set up and photograph his experiments at a depth of about fifty feet. I also did some of my graduate work on nudibranchs and their prey in Shady Cove and had traded dives with others, including my husband-to-be, while working these cold waters. Back then, the walls of Shady Cove were cloaked with many-colored carpets of sea squirts and pink anemones, each fighting for space with the next, and canopied by the gorgeous, bright-red feeding tentacles of the armored sea cucumber. The predatory clown nudibranch and fairy-white alabaster nudibranch used to be common, cruising the wall like leopards of the deep, and we hoped to find them today. So it was like coming home to be there again and see those same colorful critters. But suddenly, out of the corner of my eye, I saw it—a big flash of white, like some giant whale or shark—twenty feet deeper.
Relief flooded in as I realized the “beast” was only a specter of my imagination. Instead, we had found a band of giant plumose anemones at sixty feet—hovering like a cloud from the wall. A group of twenty huge anemones, each longer than my arm and possibly one hundred years old, stretched their stinging tentacles into the stirring current. They are magical, ghostly beings, riding the currents on their deep, ancient cliffs. For a moment I felt suspended in time as well as space, fighting the pull of the rising current, watching the columns of white bend gently as outstretched tentacles captured newly stirred plankton brushing past the wall (page 40). We moved on, fighting our way upstream, a little deeper. Once again, a ledge of ghostly white floated below, and we moved on to an ever-larger bank of anemones, stretched out from under an overhang, crowded at their bright bases with multicolored algae, sea squirts, sea cucumbers, and carnivorous nudibranchs. It was the highlight of my summer to see this familiar, richly biodiverse community unchanged after thirty years.
A creamy bank of the giant plumose anemone (Metridium farcimen), an abundant anemone in the San Juan Islands. The plush tentacles of these extremely long-lived anemones filter plankton from high currents. Photo by David O. Brown.
As the current rose, David and I stopped kicking hard to stay in place and instead drifted back along the wall. Glimpses of orange and red, the swimming and Christmas anemones, glimmered along the rocks as we slowly ascended the wall. Illuminated in the beam of light and on film, a garden of brilliant orange sea cucumbers stretched to the edges of their rocks, capturing their piece of the current with sticky tentacles. Stopping, we watched as one by one, their outstretched arms were laden with plankton and wiped clean in the mouth. Then, without missing a beat, the cucumbers redeployed their arms against the quickening flow.
Then there we were, twenty feet from the surface, in the warm and light, carried fast in the current as we took time out for our three-minute safety stop, allowing most of the residual nitrogen in our blood (the result of breathing compressed air at depth) to bubble out. And the show wasn’t over as we zoomed along—another of our Blaschka lookalikes drifted bright with us, a moon jellyfish, true inhabitant of the fast waters.
The yard-long, pure white Metridium from Shady Cove are in contrast to other anemones in the Blaschka collection: a brightly colored diversity of tentacle forms from long, slender, and pink-tipped to short, stubby, and balloon- or trident-shaped. Unlike the corals whose demise we are cataloguing carefully, much less is known about how individual anemone species slip out of even our common marine habitats. But here, beneath the familiar cold waters of my life’s work, I am moved by the elegant simplicity of this thriving white animal. It reminds me that life persists, despite the losses we catalogue every day. I let the tide carry me back to the boat, secure in my place in it all. I am ready to do it again.
3.
JELLYFISH
The Rise of the Medusa
Portuguese man-of-war (Physalia physalis) in glass. The man-of-war has been called a superorganism because it is a complicated colony of feeding, defensive, and reproductive polyps all working together. It is venomous and common in today’s oceans. Photo by Gary Hodges.
TO FIND THE WILY, often transparent jellyfish, it helps to go to the open ocean at night, which is why David Brown, Catherine Kim, and I were headed a mile out to sea from the Big Island of Hawaii. Catherine is one of our intrepid Cornell post-graduates, so entranced with diving and the diversity of invertebrate form and function that she refused to be left behind and came along as second camera. The trade winds were up a bit and the Pacific Ocean stretched very big in the offshore sunset as we motored to deep water a mile offshore. As we left the coastline behind, the Big Island seemed very small in the darkening ocean.
Of the vast groups of animals organized under the phylum Cnidaria, which includes anemones and corals, the jellyfish—or medusae—are the only mobile arm of the clan. With their long flowing tentacles, the medusae harken back to their namesake, the mythical Medusa, who had writhing snakes for hair and the ability to turn people into stone. These may be the most spectacular of the Blaschka works. They capture in detail the different forms, shapes, and colors of the free-floating medusae: the look of each delicate bell and trailing tentacle, and the different forms of jellies. This group stretches from the relatively simple but sometimes cheetah-sized oceangoing scyphozoans (page 45) with their blue, orange, or transparent bells, long trailing mouth palps, and almost infinite tentacles, to the rather austere hydrozoans, with their high, transparent bells, and the stunningly complex, colonial forms of the giant siphonophores, which include the dread Portuguese manofwar. The siphonophores have been called superorganisms because each jelly is actually an individual comprised of polyps and medusae with different functions, all integrated by evolution into one body. I am amazed at the Blaschkas’ mastery in creating a glass siphonophore. Take, for example, Apolemia, a creature that in nature stretches to over thirty feet and is composed of a swimming bell and four different polyp types—each specialized for defense, feeding, swimming, or reproducing. The defense polyps have batteries of stinging cells, the feeding polyps have a stomach, and the reproductive polyps have eggs or sperm. Apolemia looms as the largest of our models, at over a foot of transparent glass bell and trailing tentacles (page 47). I can imagine what it is like to see this in the ocean, swimming calmly through the dark waters of the night plankton, likely lit with its own bioluminescent glow.
Blaschka watercolors showing a diverse selection of jellyfish including Physalia. Courtesy of the Rakow Research Library, Corning Museum of Glass, BIB ID: 121782, 121785.
Lion’s mane jellyfish (Cyanea capillata) in a Blaschka watercolor (left) and glass. The lion’s mane is the world’s largest jellyfish, exceeding three feet in diameter, and is frequently seen in the San Juan Islands. Watercolor courtesy of the Rakow Research Library, Corning Museum of Glass, BIB ID: 122348; photo by Gary Hodges.
But there is another, darker side to this group called the jellyfish. Although they don’t literally turn people to stone, these fierce carnivores are capable of taking down a person via their spring-loaded, fast-action harpoons loaded with neurotoxins. Some species can kill a person in two minutes. The Irukandji jelly is deeply feared by Indo-Pacific divers because this tiny, almost invisible creature can deliver a sting that induces severe, even lethal symptoms, including blinding headache, backache, muscle pains, chest and abdominal pain, vomiting, sweating, tachycardia, and pulmonary edema. Death by Irukandji comes in small packages, as these jellyfish are very small cubomedusans, or box jellies, with a squarish bell about half an inch wide and four tentacles that range in length from just a few inches to up to two feet. The stingers (nematocysts) are in clumps, appearing as rings of small red dots around the bell and along the tentacles.
Now imagine a huge swarm of jellyfish, so large it colors the ocean surface purple and weighs tens to hundreds of tons. The Apolemia siphonophore, in addition to being huge, can travel in swarms so massive as to clog the intakes of power plants. In 2011, Apolemia shut down several stations in Wales (Gershwin 2013).
Massive swarms of other jellies have caused similar closures of nuclear plants. For example, in 2013 the largest reactor in the world, in Sweden, was closed by a swarm of moon jellies, Aurelia aurita, also a Blaschka match. During the fall of 2013, swarms of another Blaschka match, Pelagia noctiluca, the mauve stinger, killed tens of thousands of salmon from the Clare Island salmon farm in Ireland, after hospitalizing a swimmer with purple welts from his eyelids to his feet (Ryan 2013). While dangerous jelly blooms affecting swimmers have long been common in the Mediterranean, warming waters may be favoring blooms in the Atlantic and causing more problems for salmon farms and power plants. My favorite story of jellyfish mayhem is when the USS Ronald Reagan, a nuclear-powered aircraft carrier, docked in Brisbane, Australia. Thousands of jellyfish were sucked into the cooling system and forced a shutdown of the ship’s onboard functions. After days of battling the jellies, the carrier was forced to leave port amid headlines like “Mighty Warship Feels the Sting.” Based on these highly publicized incidents, you might think jellyfish are everywhere, but in reality, finding these extremely delicate but often dangerous animals is not as easy as poking around in tide pools. Finding the more interesting species in the group requires diving in the open ocean.
Siphonophores in glass: Apolemia uvaria (left) and Rosacea cymbiformis. The Apolemia can stretch to thirty feet in length and occur in high enough densities to kill fish in farms or clog power plants. Photos by Kent Loeffler (left) and Gary Hodges.
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