By now, we all know that global warming is not some kind of myth; instead, it is reality. Species that once stuck to equatorial waters are moving further to the north and south, and ice caps are melting at a spectacularly frightening rate. Ice breaker captains tell us that their ships no longer need to work as hard at keeping shipping lanes clear, and weird weather patterns are wreaking havoc on the planet’s human occupants. With global warming, we’re seeing some intriguing changes to ocean environments; and, we’re even seeing some new species emerging.
Changes and Threats
From tiny zooplankton to polar bears; from tropical coral reefs, to temperate ocean islands, all these are seeing changes that can be at least partially attributed to the impact of global warming. The World Wildlife Fund and Marine Conservation Biology Institute, along with many other researchers worldwide, have been conducting extensive studies ever since the threat was first discussed among scientists. Today, we are discovering that entire species could be at risk of extinction directly related to global warming. Some of these species, including polar bears, are top predators; and when top predators go, problems happen all the way down the food chain.
Not only are surface water temperatures slowly rising, so is the internal structure of the earth; massive underwater volcanoes and hot water vents are heating things up even more. As the hole in the ozone layer continues to grow, the process accelerates, adding strain to already burdened marine environments in which overfishing, destructive fishing practices, coastal development and pollution has created literal dead zones in many places throughout the world.
Weather changes that have affected human populations are destructive to marine life, too. Recent El Nino weather patterns have killed off massive segments of coral reef, caused massive fish die offs, and affected kelp forests and all their attendant wildlife, including sea birds, seals and sea lions, sharks, fish, and invertebrates.
These changes affect things we cannot see, as well as the ones we can. Phytoplankton, the base of the ocean’s food chain, is affected; these tiny plants are extremely sensitive to changes in temperature and salinity that have come with climate change. The circulation of the deep ocean between the poles and the tropics is changing, too.
In sub-tropic regions, marine populations are heading toward the poles; anemones, sea snails, crabs, fish, and other species are shifting toward cooler waters. The algae that feed tropical reefs die when temperatures get too warm; this condition, known as coral bleaching, is causing coral to die off en masse.
Not only are marine species affected; so are birds and butterflies, which are typically some of the most sensitive creatures around; a European study sponsored by the University of Leeds found that many bird species endemic to Britain had moved an average of 12 miles to the north over the course of twenty years.
New and Adapted Species
New species are being discovered all the time; it could be that recent improvements in technology have made finding new species easier, or it could be that some species are already changing and adapting to endure life on a warmer planet. Frogs and other amphibians are changing, and some animals are shrinking. A recent study in the journal Nature showed that many species, including salmon, different types of crayfish, herring, carp, scallops, and others, are maturing as smaller animals than they once were. Researchers hypothesize that this could be because these animals no longer need a larger stature to protect them from chilly weather and cool water.
One of the most fascinating examples of species adaptation is that of a fertile hybrid shark discovered in growing numbers off the coasts of Australia and New Zealand. The new shark contains DNA from both the common black tip reef shark (Carcharhinus limbatus) and the Australian blacktip shark (Carcharhinus tilstoni). The common black tip shark prefers cooler water, while the Australian blacktip shark favors warmer water. This is an extraordinary discovery since wild hybrids are much more rare than hybrids found in captivity. Researchers have theorized that the sharks are interbreeding in order to cope with climate change; the discovery has led scientists to conjecture that other shark and ray species may also be interbreeding in order to survive conditions on a warming planet.
What You Can Do
Climate change seems to have been a fact since life on earth first began. With ice ages and periods of warming documented by geologists, archaeologists, and other scientists, some people wonder whether the current warming trend is something we ought to be concerned about.
The answer is definitely yes. Prior climate changes were not caused by human intervention in the workings of nature, so far as scientists are able to tell. Mass extinctions in the past seem to have been sudden and caused by traumatic circumstances, rather than gradual and caused by circumstances within the control of a single species (humans.)
There are many major factors that are contributing to the buildup of greenhouse gases that are causing the earth’s climate to warm so rapidly. While most governments have begun to put regulations in place, many regulatory actions won’t take effect right away, and many policies are simply not sufficient to make an impact on global warming. This means it is up to us, as individuals, to take action.