Blog

Ocean Acidification Promises a Grim Future for Shellfish Unless We Take Action

Posted by on Thursday, January 9th, 2014

The phrase “climate change” has passed through the lips of every scientist and policy maker in the nation. It is a looming cloud on the horizon that has already seeped tendrils into our everyday lives. This phenomenon born of fossil-burning machines has a lesser-known cousin that is just as evil – ocean acidification.

Climate change does not cause ocean acidification (OA ). Rather they are both the consequence of industrial human activity on earth. For decades OA has been silently infiltrating our oceans, carrying a promise of death and calamity along with it. Scientists are only just now discovering the implications. OA could have profound and devastating effects on entire ecosystems and our seafood supply in the years to come, however, with proper education and positive action, people have the ability to halt OA’s awful process and reclaim our oceans.

The wicked offspring of the industrial revolution

200 years ago, humans discovered the wonders that could be wrought from burning coal rather than wood. We created amazing machines that could transport us, do our work for us and make our existence much easier than ever before. Our society flourished and bloomed into the technologically advanced race that we are today. The industrial revolution was a massive turning point in history, one that allowed both incomes and populations to boom and our entire standard of living to soar. Machines powered by fossil fuels have since evolved to meet the demands of a planet burdened by 7 billion human beings.

We are just now discovering the consequences of our advancement. Burning fossil fuels has the nasty tendency to deposit carbon dioxide (CO2) into the atmosphere. This simple gas has the potential to wreck our climate and oceans and it has only just begun it’s dirty work. We’ve bared witness to the devastation caused by hurricanes Katrina and Sandy, the ravaging of the Philippines by Haiyan and Bopha. Some might deny that these extreme weather events are the result of human activity on Earth, but soon there may not be any doubters.

The concept is abstract. It is naturally difficult for people to link the process of driving a car to work every day and the destruction caused by a super storm. But if we consider the magnitude of human activity worldwide, the concept becomes a little more tangible. Let’s consider the colossal number of man-made devices that burn fossil fuels:  billions of cars on the road, planes in the sky, and factories that power cities. All of these things deposit a tremendous amount of CO2 into the atmosphere.

Several years ago, scientists discovered that the oceans – covering 70% of the planet earth – were absorbing CO2 like a kitchen sponge, up to 1/3 of all human emissions. That means that 22 million tons of CO2 is entering the ocean every day. At first scientists rejoiced, thinking this could solve the problem by lessening the amount of the terrible gas in Earth’s atmosphere. Then we realized all this accomplished was the creation of another problem – ocean acidification.

Acid in our oceans

When CO2 is absorbed by ocean water, a complex chemical reaction takes place. CO2 sequesters carbonate, naturally found in our oceans, and bonds with it to form bicarbonate ions. These ions then disassociate (break down) into carbonic acid and hydrogen ions. A higher concentration of hydrogen ions means a higher acidity level.

There is no doubt that the very chemistry of our oceans is changing. Over the past 300 million years our oceans have averaged an 8.2 on the pH scale, or slightly basic. All the ocean’s beautiful and unique ecosystems have developed under these conditions. Today the average pH of the oceans is 8.1. This doesn’t seem like a very big change, until we consider the fact that the pH scale is logarithmic. Each one-unit change in pH corresponds to a ten-fold unit in hydrogen ion concentration. So a change from 8.2 to 8.1 means that there has been a 25% increase in acidity in the last 200 years.

So why should we be concerned with an increase in ocean acidity? The first major problem is actually the initial step in the chemical reaction above – the removal of carbonate from the equation. Shelled animals such as oysters, clams, mussels, corals, krill, and countless others all have calcium carbonate skeletons and shells. They seize carbonate from the water that surrounds them, using it as a building block to construct their shells. If there is less carbonate available, it is much more difficult for these organisms to survive. Shells and skeletons are thinner and weaker; more energy is wasted trying to take up less carbonate. The very environment they live in becomes caustic as hydrogen ions increase in concentration.

 

Let’s be silly for a moment and remember the three little pigs from our childhood stories. A healthy, thriving shellfish has the house made out of brick, for the most part impermeable to the big bad wolf – or any predator. A weakened shellfish will have a wood house, not nearly as protective as brick but still offers some measure of security. An acid ocean in 50 or 100 years may create shellfish that have a house made of straw, easily broken down and destroyed. These softer, weaker animals are extremely vulnerable to predation and parasites and entire populations could be wiped out very quickly.

This is not saying that beds of oysters are going to suddenly start melting like the hull of the ship in the movie “Alien” from dripping acid blood. The more troubling thought is what will happen to the larvae of those oysters over time. The change will be gradual, slowly affecting baby shellfish with each spawning season. As the developing larvae become weaker, softer, and more vulnerable, the number that makes it to adulthood will begin dropping.  It might happen slowly at first, but a more rapid process is eventually assured.

Many shelled animals are broadcast spawners, which means they produce millions of tiny microscopic babies that make up plankton. Many animals rely on plankton as an critical food source. If shelled animals begin disappearing, so will animals higher up on the food chain. A significant casualty would be krill, an essential organism on the menu of a complex ocean food web. Not only may shellfish disappear, but we would also ultimately say goodbye to  fish, sharks, seabirds, dolphins, and even whales.

Humans can make the change

We are only just beginning to understand the implications of ocean acidification. Research on OA is in the infant stages and we still have so much to learn. There is one thing we do know with absolute certainty – we can slow and even halt the process of ocean acidification by changing our every day activities. By making simple, easy adjustments, each and every person can have a huge impact. It is amazingly easy to lower our carbon emissions.

Carpooling, taking public transportation, using alternative forms of energy such as solar and wind power, turning off lights, unplugging appliances – the list is endless. Check out easy and simple ways to reduce your carbon footprint. If you and your clients are shellfish lovers, I would urge you to support businesses that use green practices. Pucci Foods is a leader in adapting and utilizing technology to reduce their carbon footprint. Make the change today and save our oceans for tomorrow.