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Global Warming and Acidification of the Oceans

| Mark J. Palmer
Topics: Cetacean Habitat

This is the third of a series of articles on the impacts of global warming on marine mammals.  

Global warming is being caused by gases that are emitted by human activities – particularly the burning of fossil fuels, methane from livestock and warming permafrost layers, and the cutting of trees and pollution of the ocean which impedes the absorption of excess greenhouse gases like carbon dioxide and methane.  

What can you do?  Use less energy and eat less meat, for starters. See below for more ideas.

Our Earth is getting warmer, as the atmosphere that surrounds us gets higher and higher concentrations of “greenhouse” gases.  Gases like carbon dioxide and methane allow light to be transmitted, like a pane of glass in a greenhouse, but do not allow the warmth to be radiated back into space.

There are many sources of greenhouse gases, but burning of fossil fuels and the raising of livestock, coupled with cutting down of forests and pollution of the ocean which reduces the absorption of greenhouse gases, are major culprits.

Some of the excess atmospheric carbon dioxide, about 30-40%, will sooner or later be absorbed by our oceans.  Indeed, we can already measure higher levels of acidity in the ocean now.  While that is good news for the atmosphere, it is bad news for the ocean’s inhabitants.  When carbon dioxide enters the ocean, it is changed chemically into carbonic acid.  This has the effect of changing the saltiness of the oceans, making the waters more acidic.

There are numerous negative impacts on marine life from our oceans getting more acidic.  For one thing, organisms that use calcium from seawater to form shells find it harder to pull the calcium from seawater as the waters get more acidic.  This chemical imbalance will mean the likely extinction of many kinds of hard-shelled creatures.  Coral polyps will find it harder to build coral reefs, which are already being harmed by warmer surface waters, causing the death of living corals worldwide.

Several whale species depend on shelled animals for their food.  For example, krill are small shrimp-like organisms that occur in huge numbers during the summer months, providing food for a variety of endangered whales, including the filter-feeding baleen whales like the blue whale and the right whale.  Gray whales are bottom feeders on amphipods, small, shelled organisms that live and burrow through bottom mud of the Arctic Ocean.  Even whales that eat fish are dependent on krill to provide the food for fish.  Experts fear the entire food chain could collapse.  

Recently, several scientists have conducted experiments with several fish species, including those that live in coral reefs and some sharks.  They have found that when such fish are put in seawater that has been brought up to levels of acidic concentrations expected in 2100 (should current fossil fuel burning continue) these fish fail to respond to the smell of predators or food.  Apparently, the acidity somehow interferes with their ability to smell and react appropriately to food and predators.  Here again, the entire ocean food chain could be disrupted by ocean acidification.

There are, of course, many other problems for whales and dolphins in the world’s oceans – direct killing of whales and dolphins by Japan, Iceland, and Norway; warmer waters; ship strikes on whales; increased pollution, particularly plastics and toxic materials; and oil drilling with attendant noise and potential for oil spills.

Our oceans and our whales and dolphins need our help to address these problems.


Reduce your use of energy – walk or bike to work, buy an electric or hybrid car, turn out lights when not in use, put computers and other household appliances on energy strips (such items leak energy when plugged directly into electricity outlets, even when turned off), wear a sweater and turn down your thermostat, avoid using air conditioning. and buy low-energy light bulbs and appliances.

Urge your state and federal representatives to take action to prevent global warming.  There are many actions that must be taken to reduce the production of greenhouse gases that cause global warming.  State legislatures and the Congress SHOULD be leading the way for an economy based on substantially reduced fossil fuel use.  Solar, wind, and hydro power can replace burning fossil fuels with clean energy.

Reduce your eating of meat, as livestock release large amounts of methane gas, which is an even more potent greenhouse gas than carbon dioxide.  Why not go vegetarian or vegan?  You will eat better and help avoid the needless killing of livestock, too.

Support the efforts of Earth Island and other organizations to reduce global warming!

Thanks for your support – the dolphins and whales will appreciate it!