Spinner dolphins never stop talking. Even from the level that snorkelers inhabit--the water’s surface--dolphins’ chatter resounds clearly from hundreds of feet below...then dozens and finally just a few feet below as they swim toward the surface en masse. On Hawaii’s west coast, the dolphins swim and play in several shallow bays including Kealakekua, Pu`uhonua O Hōnaunau, and Ho’okena.

Pu`uhonua O Hōnaunau
 The dolphins are pirouetting skyward. The whole school of them rotates along one axis, but there are solos and doublets amidst the larger symphony. Two dolphins swim side by side, touching fins like a couple holds hands. Another pair twirls, stomach to stomach, while ascending.

They break the surface in unison, cavorting across the plane of water like gravity had suspended itself momentarily. After a brief moment of fins roiling the water, some begin airborne acrobatics. Spinner dolphins can breach, of course, but not merely arc across the water to return. Some launch from the water, then fall with a loud belly flop. Others forward flip with a triple axel, a move that would win Olympic gold if any human could perform it, if we even had the skills to convene such a competition. On the subject of the Olympics, scientists have observed spinners making seven rotations in the air. Even drug-addled Russian athletes can’t come close. Spinners tricks can be as rambunctious as they are refined. After completing  a triple axel, one may simply launch straight into the air and crash down haphazardly.

If you are watching a group of spinner dolphins put on such a display, they may seem like the most relaxed, secure, well-fed species on the planet. Most people, after all, don't while away their days in aquatic gymnastics. This is in fact the leisure time of spinner dolphins, who hunt at night in deeper water and come frolic in shallower waters the mornings after. Thus, if you see spinners cavorting in the afternoon, they are like late night revelers who will see the sun come up before going to bed.

These are only half anthropomorphic conjectures. Scientists have documented spinner dolphins’ humbling social behaviors. Spinners do in fact hold fins like humans hold hands; scientists have even observed them playing the dolphin version of “patty cakes.” They are hopeless romantics who pair off, but also switch pairs.

Those late afternoon revelers, though, may or may not be after all: Spinner dolphins turn off some of their senses, such as echolocation, and leave on others such as eyesight while sleeping. They sleep while swimming, and since they are more vulnerable without the full range of senses, they prefer to sleep in shallow, sandy-bottom bays where lurking sharks could be spotted below. In theory, a pod of sleeping dolphins could in fact be swimming around a group of humans.

Observing the dolphins in person, clearly the airborne ones are not asleep. I don't care how agile they are: forward flip triple axels are not somnambulant behavior. But science around dolphin sleep certainly matters. Spinners have been wiped out of much of their former east Asian habitat as fishermen have killed them as yellowfin tuna bycatch. Around North America, localized harassment by tour boats can be more of a threat. So from the individual swimmer’s perspective, it isn't responsible to swim into a group of dolphins.

But what should we make of spinner dolphins who come into a cove thronged with snorkelers, when other neighboring coves are empty?


Pu’uhonua o Honaunau is renowned as prime coral habitat, and thus as a premier snorkeling destination, near Kona, on the island of Hawaii. Locals call the snorkeling area “Two Step.” The bay is deeply indented, with long coral trenches that extend seaward from harsh lava beaches. Coral, like glaciers, can be mind altering in their ability to reconfigure your sense of time, space, and geography. At first glance, the seafloor is five feet below the water’s surface. Swim a few feet further, and massive trench descends dozens of feet to a narrow strip of light sand below. Billions of coral polyps have built the “seafloor” you are observing, and the geologic seafloor is far below. Those same coral polyps shaped an entire ecosystem: the spinner dolphins and sharks that eat the reef fish, the Polynesians who subsisted largely off fish as they colonized the Hawaiian islands just one or two thousand years ago, and the modern fishmongers and chefs and sushi makers and fishermen.

Today, much of Hawaii’s coral is a graveyard. “Two Step” has some living coral, but much more is bleached. Based on the current carbon dioxide pollution trajectory worldwide, it is highly likely that at least 90-98% of coral worldwide will perish. The chemistry is simple: Carbon pollution mixes with ocean water after entering the atmosphere, turning seawater into an increasingly corrosive carbonic acid. A dizzying array of species are at risk, including just about every species that depends on coral for food or habitat.

Based on both locals’ recommendations and the Big Island’s definitive guidebook, the north side of Kealakekua Bay, which is near Two Step, is the best snorkeling on the island. It has no development adjacent to it, and snorkeling access requires a boat or a hot, steep hike miles down from the highway. Unlike some more accessible and developed beaches, clearly neither swimmers nor near-short effluent is the cause of coral die-offs.

North Kealakekua Bay has a simple white obelisk commemorating the death of Captain Cook. His death in this location followed two events. First, one of his crew members died, and Cook held a burial for him in view of Native Hawaiians, many of whom previously thought that Cook and his men were gods, and immortal. Second, Cook got in an argument with some Native Hawaiians. Freed from their previous trepidation about killing a deity, a local killed Cook in shallow water in Kealakekua Bay.

Nobody will make epic paintings, a la Cook’s landing in Kealakekua, of today’s foam and plastic watercraft. Most tourists arrive at the bay’s coral by a large motorboat from Kona, or a plastic sit-on-top kayak that can be rented on the south side of the bay. Some of us travel by even less elegant means: I cross the bay on a boogie board, white-man floppy hat shading my face, flippers on my feet, and a snorkel and mask awkwardly wedged into the little loop of fabric near the front of the boogie board.

There are many good reasons that nobody uses boogie boards from for long distance travel: inefficiency, misery, inability to transport any gear. But for those of us who don't have enough body fat to float, it's marginally better than drowning. After an eternity of kicking across the bay, it is a supreme disappointment to find that the coral has nearly all perished. And that I’ll have to paddle back across.

In 2018, it is difficult to imagine the coral that Cook would have witnessed had he donned a snorkel mask before anthropogenic carbon pollution and its associated ocean acidification. Hawaii’s coral, like it's terrestrial species and ecosystems, is unique, due to the archipelago’s isolation. New species arrived on the islands at a rate of only one per ten to twenty thousand years, orders of magnitude slower than the rate of speciation on mainland areas or near-shore islands. As a result of isolation, Hawaii developed hundreds of endemic species, which means they are native to the islands and exist nowhere else on Earth. That includes coral and its fish inhabitants.

Kealakekua’s coral is mostly bleached, as is every other reef I've visited on Hawaii’s west coast. Within just yards of the obelisk commemorating Cook's death, much of the bleaching seems recent: A few skeletons of what appear to be antler coral still rise from the seafloor, but are covered in algae. If the “healthiest” coral on the Big Island is dead, it's safe to be assume little shallow water coral will remain for much longer anywhere around the island.

Like glaciers, coral disappears slowly. First the most extravagant corals break off, leaving towers and trenches that are more resistant. One type of mounding coral, Porites Lobata, now dominates what remains of living corals in the bays on Hawaii’s west coast.

The global disappearance of coral is no accident, but a direct and predicted result of global warming pollution that had enriched a few individuals at the expense of billions of other humans and countless other species. It is remarkable that even the perpetrators of this crime acknowledge the bounty of their theft isn't worth it. William Koch, one of the brothers of the family that colonized the Republican Party and played a central role in gutting America’s democratic institutions that otherwise would have responded to climate change, recently auctioned off 20,000 bottles of wine from his collection. Koch acknowledged, finally, that he simply couldn't drink it all. Lesser plutocrats have had the chance to buy bottles for as much as $120,000 each from Koch. Each bottle represents a tawdry conversion of natural capital, open to the enjoyment of everyone, into a single glass bottle of sour grapes, to be consumed privately in a dark room of corpulent billionaires. In place of coral, a place teeming with so much life that the eye cannot absorb or comprehend it, is an empty bottle, refuse.


We are living through what scientists call the “sixth extinction,” so named for the unusual scale and unprecedented rate of death of thousands of species. Freak astronomic or geologic events caused the previous five global extinctions; we continue to cause the sixth. There is a key difference between the first five and the current mass extinctions: ours is occurring far more rapidly, with many environmental changes occurring at a faster rate than species can respond through evolutionary adaptation.
Climate change, in conjunction with extensive habitat destruction and anthropogenic distribution of invasive species, is killing other species faster than the earth has ever experienced. Hawaii is ground zero.

Though its tourist reputation is for beaches and resorts, Hawaii is home to diverse and rugged habitat ranging. With elevations nearing 14,000 feet, and extreme differences in precipitation based on the ocean and prevailing winds, Hawaii has habitat ranging from coral reefs to deserts to rainforests to permafrost-encrusted peaks.
Though they receive little popular attention compared to coral reefs, Hawaii’s rainforests are no less astonishing. Ecologically, they are even more unusual. While most tropical rainforests have their maximum density and diversity of life in the canopy, Hawaii’s rainforests host most endemic inhabitants near ground level. Central American rainforests have dozens if not hundreds of canopy tree species, Hawaii has two: the ohi’a lehua (metrosideros polymorpha) and the koa (acacia koa).

The ohi’a is a keystone species--that is, essential to the survival of numerous other species in its ecosystem--like no other. In most forest systems, certain species colonize new or recently disturbed ground, only to be displaced by the “climax” species that ultimately dominate the canopy. In Hawaii, ohi’a is both the primary arboreal colonizer of lava and also the dominant canopy species. Countless species depend on it, for the nectar in its flowers or the shade from its leaves or the earth it creates as its leaves fall and turn to soil.
Victims of Rapid Ohi'a Death

The ohi’a has developed some remarkable adaptations to colonize the Earth’s newest land: lava fields that in many cases are just a few years old, including in terrain with ongoing volcanic activity. Ohi’a have sensors that can detect dangerous levels of sulfur dioxide pollution, which volcanoes produce. When vents are producing unusually concentrated levels of sulfur dioxide, the ohi’a pause respiration till cleaner air is available. In another innovative development, they harvest water from the air: Ohi’a have root sacks that dangle from their branches. When light rains or clouds pass through, these airborne roots allow the ohi’a to collect water that wouldn't otherwise filter down through the canopy to their root systems. Ohi’a leaves are uniquely adapted as well. They are thick and feel leathery, like the leaves or needles of succulents. This helps them retain moisture and protect themselves in the intense tropical solar exposure, whose effects are greatly magnified by expanses of black and grey lava that elevate ambient temperatures and associated evaporation rates.
Nene, Hawaii's (endangered) state bird, and a relative of the Canada goose
As a result of the ohi’a’s ability to colonize lava fields and create rainforest out of barren rock, dozens of other species have developed to thrive in Hawaii’s unusual ecosystems. Among these are, or were, more than 40 species of honeycreepers, birds that drink from and pollinate trees such as the ohi’a. While many of Hawaii’s endemic honeycreepers have gone extinct, primarily as a result of habitat destruction and invasive species such as mongoose, pigs, and feral cats, a few survive. The Apapane, a vibrant red and black bird, is among these. Unlike many threatened species, the Apapane is accessible to the casual tourist: Spend ten minutes in the ohi’a-dominated rainforest of Volcano National Park, and you will hear numerous Apapane singing and flying in the canopy. Their songs are joyful, particularly during the long mornings when they start singing around dawn and perform exuberantly for hours. Hearing just one song of the Apapane is an inestimable privilege, a window into a former world thronged with life.
Today, vast swaths of mature ohi’a forest are dying of a fungus called Rapid Ohi’a Death. An invasive species, the fungus is currently limited to Hawaii, but that is also home to most intact, unfragmented rainforest in the Hawaiian archipelago. Since ohi’a is the keystone species for this rainforest, it's death will have sweeping impacts on the ecosystem. Loss of the colonizer means vast swaths of lava will take far longer to become forest, as the beneficent ohi’a canopy will not provide shade and earth to nurture tree ferns, thornless hollies, and other species that grow in the mid and understory of Hawaii’s rainforests. Loss of ohi’a makes it even more difficult, perhaps impossible, to sustain Hawaii’s last surviving species of honeycreepers, such as the Apapane, whose primary food source is ohi’a blossom nectar.
Without this improbable settler of lava fields and nurturer of rainforests, it is difficult to imagine how Hawaii’s other trees and shrubs will give life to the new earth that continues to emanate from Kilauea.
Tree fern midstory under an ohi'a canopy, in Volcanoes National Park
The twin threats of climate change and invasive species have the appalling ability to render unrecognizable landscapes that we humans have known for thousands of years. Entire nations are disappearing under rising seas, while retreat of sea ice is making subsistence ways of life incredibly difficult for many western Alaska communities. In Hawaii, this is what the sixth extinction looks like: Destruction of vast swaths of the species that not only anchors her rainforest ecosystems, but colonizes lava so just about all other species can live on the islands.
Ohi'a colonizes the forty year old Kilauea iki lava field

Evolution is a remarkable system, and if the ohi’a substantially perishes, some other species will evolve to fill its niche. In geologic time, it’s all a wash. But generations upon generations of humans may see Hawaii’s new lava uncolonized by ohi’a, and have no idea that those expanses of black rock could have been inhabited by ohi’a and dozens of other species. Tree ferns could have grown up under their arching branches. Apapane could have flitted in the canopy, singing their morning chorus. When a species like the ohi’a dies as a result of climate change or invasive species, it can take the whole forest with it.


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