Managing Our Invaluable Coastal Ecosystems in a Changing Climate
Are we loving our coasts to death?
Part I—Introduction and Overview
Our coastal ocean ecosystems provide us inestimable ecological, recreational, and economic benefits. Our populations flock to these coastal areas, both as full–time residents and as vacationers. The notion that we as a species yearn to return to the sea is one familiar to all of us from our earliest readings and first visits.
Which in a way is part of the dilemma: we may be loving our fragile and highly vulnerable coastal resources literally to death.
NCCOS scientists for years have been assessing and reporting on the full range of social and environmental “stressors” affecting our coastal ocean resources: extreme natural events such as hurricanes and droughts; introduction of invasive species; a wide range of environmental pollutants and contaminants; and mounting land, resource, and development pressures.
In recent years, with significant advances in scientific understanding of the underlying physical and earth science principles involved, NCCOS finds itself exploring these stressors not in isolation, but rather in combination. One lesson is clear: Their synergistic impacts can be far more detrimental than risks posed by any one of them alone. That improved understanding in part accounts for the ecosystems–management approach NCCOS science has been committed to over past years.
Weighing Climate Change. A ‘Force Multiplier’?
Some researchers say coastal storms may be growing stronger due to warmer water off of the coast. Now more than ever, NCCOS also finds a need to understand these stressors and their individual and collective impacts in the context of the changing global climate. Our changing climate increasingly is influencing, and even driving, each of those other stressors. That is the reason some have come to refer to climate change as a “force multiplier,” a military term referring to one factor that can dramatically increase the impacts of others.
As in the past, NCCOS scientific research will continue to reflect the highest “gold standards” of scientific understanding, both that resulting from research conducted by our own staff scientists and our grant–funded partners and also that undertaken nationally and internationally by the world’s most respected scientific organizations.
NCCOS’s special niche in this critical ongoing effort will be to focus that growing scientific understanding on our nation’s broad range of coastal ecosystems, including estuaries, coral reefs, marshes, mangrove forests, and all nature of shorelines—anywhere that streams, rivers, seas, tides, and coastal currents mix.
A 16–page special report on the seas in the January 3–9, 2009, issue of the respected Economist magazine summarizes the situation in this way:
“.in the surface and coastal waters where 90% of marine life is to be found, the impact of man’s activities is increasingly plain. This should hardly be a surprise. Man has changed the landscape and the atmosphere. It would be odd if the seas, which he has for centuries used for transport, for dumping rubbish, and, more recently, for recreation, had not also been affected. The evidence abounds.”
It is precisely these areas—that is, the counties in coastal areas within 50 miles of our coastlines—that more than one–half of our population calls home. It’s where more than half of us make our livings and our careers and where we raise our families, and where we seek recreation. It’s this same area that provides us invaluable buffering protection from the flooding of pounding storms; that provides us the vast ecological services and benefits of much of our wetlands; and that offers so much to help feed our hungry and growing population.
But there is a paradox.
This same coastal ocean area faces daunting and increasing pressures not only from the traditional environmental stressors, but now in combination with the significant risks posed by anthropogenic (human–caused) climate change and the resulting higher land and ocean temperatures documented globally by direct observation over recent decades.
Climate Change Impacts to be Highlighted
NCCOS postings to this site throughout the coming year will detail the wide range of our scientific research into these issues and how the coastal resources we so cherish and value are themselves in the proverbial crosshairs of projected impacts from climate change. Consider just a few initial examples, each of which will be further detailed in coming months’ NCCOS features:
Globally, it’s getting warmer—Surface air temperature records over continents and islands document that warming has accelerated over the past half–century, with the rate of warming over the past 50 years nearly twice the rate of the past 100 years. Scientists say the warming trend is here to stay over the next century, notwithstanding some occasional short–lived anticipated cooler periods. NCCOS scientific research increasingly will inform our policy makers of implications of this ongoing warming for our coastal ecosystems.
Warming Ocean Temperatures…and Sea Level Rise—You wouldn’t know it from taking a casual dip at the beach on a sunny day, but research led by NOAA documents that all the world’s major oceans have warmed down to a depth of 3,300 feet (1,000 meters) by a global average of slightly more than one–half degree Fahrenheit (0.3 °C). That may not sound like a lot to the casual bather, but we all know that water expands as it warms, leading to real concerns about sea level rise. Don’t think of it solely as a matter of our increasing coastal area populations and infrastructure being at risk of increased flooding. Along with people and property, more storm damages, increased coastal surges, more coastal erosion, increased salt water intrusion, and resulting risks to fresh water pose resource management challenges for wetlands and entire coastal ecosystems.
Ocean Acidification—The increased acidity level of the world’s oceans has garnered substantial media and public interest in recent years. The reasons are clear: Coral and shellfish calcification and growth and reproduction potential are highly sensitive to acidity levels in the seas. Research published in Science magazine in late 2007 by authors including a NOAA scientist expressed concern that, even in using conservative lower–range scenarios of impacts, analysis points to “serious if not devastating ramifications for coral reefs.”
Freshwater Impacts—Rising sea levels and increased ocean acidification have garnered lots of headlines and attention, but widespread changes in precipitation patterns—more in some areas, less in others—also will need close watching from the scientific community if we are to effectively manage our coastal ecosystems. From the potential for more inundations to prospects for more drought–like conditions and implications for potable drinking water supplies—it’s all what comprises the daunting smorgasbord of climate change impacts facing tomorrow’s coastal resource managers.
Coral Reefs—Scientists agree that coral reefs are among the planet’s most biologically diverse and economically significant ecosystems, but research shows they also are deteriorating as a result of human activities, including climate change. Higher sea surface temperatures are contributing to mass coral bleaching and disease epidemics plaguing our nation’s coral reef ecosystems. Warming and acidifying seas are contributing significantly to this ongoing deterioration of our vital coral reef ecosystems. For more information, see NOAA Technical Memorandum/NOS NCCOS 73, dated April 2008 (The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008, available as a free PDF file.
Harmful Algal Blooms—The growing incidence and severity of harmful algal blooms (HABs) has become a significant concern among the world’s ocean scientists in recent years, as HABs have significant adverse impacts on human health, coastal economies and ecosystems. Just how a warming climate and warming ocean temperatures may affect HABs remains a matter of research, but indications are that HAB distributions—where precisely they occur and for how long—will be affected by our changing climate, in some cases for the better, and in other cases for the worse. Scientists are watching closely to understand how the changing climate may also affect nutrient runoff into our coastal estuaries, as increased runoff also would likely contribute to more and more severe HAB events.
These and other important coastal ocean activities will be addressed in NCCOS web site features every other month throughout the remainder of this calendar year. It all adds up to a busy—and fascinating—year for NCCOS scientists and coastal ocean science generally. Look for additional details in coming months on how NCCOS scientists are addressing climate change impacts as a key part of improving our overall scientific understanding of our critical coastal ocean ecosystems.