Selflessness doesn’t just benefit recipients, but those on the giving side of the
equation, too. The bonus: There are so many ways to give, whether you are being
charitable with your money, time or love. Here’s what science says about
altruism and how it enhances all our lives.
Armed with test strips and color-coded charts, aquarium enthusiasts carefully follow an elementary rule: Watch your pH. But the pH of our oceans has been carelessly tipped off-kilter, and the resulting environmental changes can cause immense harm.
Environmentalists decry the carbon-based power surge that started with the Industrial Revolution and has mushroomed into a gluttonous fossil fuel feeding frenzy. The massive outpouring of carbon dioxide exhaust from fossil fuel consumption is blamed for a number of environmental concerns, from global warming to the lesser-known but equally devastating consequence of ocean acidification.
“Ocean acidification may present one of the gravest threats to our planet’s ecosystems and yet it is also one of the least publicized aspects of the global climate change issue,” says David E. Guggenheim, PhD, president of 1planet1ocean (www.1planet1ocean.org) and a consultant in conservation policy and science. “Ocean acidification is occurring very rapidly, causing unprecedented changes to the chemistry of the oceans.”
A quick chemistry refresher: pH is a scale, ranging from 0 to 14, that is used to measure acidity (pH below 7) or alkalinity (pH above 7). The pH is determined by the activity of hydrogen ions (H+). If a compound is acidic, it breaks down in water into positively charged H+ ions; if a compound is alkaline, it breaks down in water into negatively charged OH- ions. Our oceans soak up CO2, which then breaks down into H+ ions, acidifying the waters and making them less habitable.
But pH changes in our oceans are nothing new. “If you look at the last 600 million years, there’s been a huge variability of CO2 in the ocean,” explains James Barry, senior scientist with the Monterey Bay Aquarium Research Institute (www.mbari.org). “Whenever CO2 has really gone up rapidly, we’ve seen massive extinctions on earth. The biggest is 250 million years ago when Siberian volcanism ejected lots of CO2 into the atmosphere; at that time about 90% of all marine genera died. That’s one of the pieces that makes us think rapidly changing CO2 in the ocean can affect marine life.”
Though we may not yet match prehistoric supervolcano eruptions, humankind is churning out way too much CO2. Experts estimate that since the Industrial Revolution, roughly half of the human-produced CO2 emissions have been absorbed by the oceans. The numbers complete the story: Pure water has a pH of 7; seawater in pre-industrial times was approximately 8.17. Today, pH of surface ocean water has decreased to 8.07. Because pH is measured on a log scale, a decline in pH of 0.1 means there has been a 30% increase in acidifying H+ ions. “This is a big change,” says Marah J. Hardt, PhD, research fellow with the Blue Ocean Institute School of Marine and Atmospheric Sciences at Stony Brook University (www.blueoceaninstitute.org). “It is the fastest rate of change the oceans have ever experienced, as far as we know. It is due to the rapid rise in carbon emissions caused by human activities, mostly burning fossil fuels.”
A Chain Reaction
So will oceanic life go belly-up, just like fish in an aquarium with out-of-whack pH? It’s not that simple, but the consequences could be broad. “This is a profoundly serious problem that threatens to impact virtually every aspect of the chemical and biological functioning of the oceans as we know them today,” says Guggenheim. “Ocean acidification threatens to undermine the function of the ocean’s major ecosystems, including the majority of the world’s coral reefs, potentially causing an unraveling of the ocean food chain, large-scale extinction events, and impacts on the oceans’ commercially important fish stocks.”
Calcification, a critical function to aquatic life forms and the oceanic ecosystem, is a central acidification concern. “Calcification is the process by which corals, algaes, mollusks, etc. build their shells, plates and other structures from calcium carbonate,” explains Guggenheim. “Laboratory results show that an acidic ocean would make it impossible for these plants and animals to build their calcium carbonate structures. Essentially, their shells, plates and other structures would be dissolved faster than the plant or animal could build them.”
Poor calcification could trigger a far-reaching chain reaction. Pteropods, shelled marine plankton that are a primary food source for such species as herring, salmon and mackerel, are particularly susceptible to ocean acidification, and could dramatically decline. “What is scary is that we don’t know what will happen—ecosystems have been tuned over millennia and when we tweak one component, many cascading effects can occur,” observes Hardt. “If some of these marine plankton are wiped out, it could alter feeding patterns in fish, or result in collapse of some fish species that might not be able to feed on different prey.”
The food chain extends beyond the ocean as well; seabirds, seals, bears and people all depend on marine organisms for sustenance and nutrition.
A food-chain ripple that starts in the ocean could easily spill over into land-bound food chains around the globe. “One billion people rely on seafood as their primary or only source of protein,” notes Hardt. “Messing with this resource is thus very risky business.”
Even marine life forms that may not have apparent food chain links to plankton like pteropods may suffer; all marine organisms could be affected by fluctuating pH. “Changes in ocean chemistry affect the internal chemistry of marine animals, and we do not know what kind of effects this could have on long-term growth, reproduction, immune efficiency” and other dynamics, says Hardt.
Acidification’s ill-effects on marine life don’t stop there. “In a more acidic ocean, animals undergo respiratory stress, which means that they can’t carry as much oxygen to their tissues,” says Barry. “To compensate they can either ventilate more rapidly and pump blood more rapidly, or reduce their aerobic scope...which means they can’t run from predators or chase prey as much.”
Metabolic depression is yet another internal side effect. CO2 is an anesthetic and may actually make deep-dwelling marine species sluggish. If marine animals must expend more energy struggling with CO2 side effects, functions critical to survival lag. “If you can tolerate the stresses associated with CO2, the consequences are you’re probably not going to grow as much and you may not have as much energy to go into reproduction,” says Barry. “Populations may then have a reduced resilience to rebound from things like fishing or environmental events. Combined with acidification, it means we probably will lose some species.”
Loss of corals—the calcifying marine organisms that build coral reefs—may have even more far-reaching repercussions. “Both in the tropics and the deep cold waters, corals form complex structure that serves as the home for many species,” explains Hardt. “If corals dissolve because of acidification, it means the loss of homes for hundreds of thousands of species. This is the real housing crisis of the 21st century.”
In addition to providing housing for fish, coral reefs protect the homes of land-based coastal residents by buffering them from the waves and storms. “Many countries depend on coral reefs for food, tourism and fishing; their economies run on the oceans,” says Barry.
Known as the “rain forests” of the ocean, coral reefs also provide abundant nutritional and medicinal compounds. But like the rain forests, coral reefs are vanishing, with acidification adding to existing stressors like temperature changes, nutrient pollution and overfishing. “Coral reefs are really in peril, and by the end of the century they may largely be gone,” Barry explains. “If you’ve got kids, take them to a coral reef now.”
While the consequences of ocean acidification may start with the decimation of aquatic organisms, the full extent of its potential impact is simply immeasurable. The loss of marine life means less sustenance for people and could potentially create a shortage of ocean-derived health-boosting nutritional supplements, including astaxanthin, fish oils, glucosamine and more.
Since marine shells comprise the sediment that draws carbon dioxide from the atmosphere, it’s possible that acidification could also limit the amount of CO2 the oceans absorb. Such a scenario would exacerbate global warning, meaning loss of glaciers, fresh water shortages, fierce storms, warmer oceans and other environmental catastrophes.
The solution is as clear as crystal-clear tropical waters revealing a colorful coral reef below: Drive less, reduce carbon footprints, conserve energy and live locally. “We must rapidly mobilize to transform our civilization from one dependent on finite energy sources to one that uses the infinite energy sources that solar, wind, and other renewable sources supply,” says Hardt. “The only thing that will help stop acidification is to decrease emissions.”