Understanding the Changing World Between Land and Sea
Along the northwestern tip of the continental United States, large rocky stacks rise like sentinels from the mist.
Shrouded in beauty and wonder, the expansive coastline of Olympic National Park sets a dramatic stage for the convergence of several unique ecosystems.
Pristine, glacier-capped mountains painted in lush rainforests descend swiftly into the crashing waves where land meets sea.
Leafy algal turfs, bright sea stars feasting on tightly intertwined mussels beds, and a menagerie of critters protected by hard outer shells abound in the rocky intertidal zone at Olympic National Park.
Designated by UNESCO as an International Biosphere Reserve and World Heritage Site, this protected and undeveloped stretch of coastline boasts some of the highest biodiversity of marine invertebrates and seaweeds on the West Coast of North America.
A zoomed in texture of the back of a sand dollar. Image in black and white.
A small lined shore crab pokes body out of a hole in the rocks. Image in black and white.
Zoomed in textured photo of small white barnacles clustered tightly together. Image in black and white.
The intertidal ecosystem represented here is a dynamic environment characterized by change. The rising and falling tides dictate daily life for animals and plants that call this space home.
Over hundreds of years, in order to survive, species have learned to adapt to crashing waves, extreme temperatures, and general stress resulting from life in a high impact environment.
In the foreground, a blurred rock. In the background a group of eight intertidal researchers huddle together in discussion with the calm ocean behind them. Image in black and white.
As acting stewards of these lands and seas, the National Park Service (NPS) has monitored this critical ecosystem for the past three decades.
Clad in their sturdy rubber boots and equipped with bright yellow measuring tapes, NPS biologists regularly make the trek down the sandy beach to check in on the tidepool residents. They monitor and report on changes in their numbers and overall health.
Grayscale map of the United States with data collection sites denoted by small light blue circles along the western edge of North America from Canada to Mexico.
This site, one in over 200, comprises a long-term effort along the western seaboard known as the Multi-Agency Rocky Intertidal Monitoring Network. Appropriately acronymed - MARINe.
Despite these valiant efforts of protection and monitoring, the world is changing. Our natural ecosystems and their inhabitants face perils like never before. Habitat destruction, pollution, extinction events, invasive species, disease—the list of existential threats is long and ever growing.
A large seastar clinging to a rocky outcrop with half of body out of the water. Image in black and white.
Two large volcano like barnacles on a rock surrounded by small shell fragments. Image in black and white.
For decades scientists have unanimously warned of the ever increasing levels of greenhouse gases in our atmosphere. As a result of human-induced fossil fuel emissions and land use alterations, these increases have led to an exponentially warming planet.
On our current trajectory and without an international effort to curb and reduce carbon emissions, the Intergovernmental Panel on Climate Change (IPCC) warns of a global temperature increase of 1.5°C by mid-century. We are already experiencing the consequences. Melting polar ice, rising seas, extreme weather events, wildfire, and more—the impacts are boundless and compounding.
A coastal location with a large cliff to the left and water swirling around rocky outcrops in the foreground. Image in black and white.
Since life on this planet began, the ocean has helped regulate the balance of our global system by absorbing heat and carbon dioxide. With both now in high abundance in our atmosphere, oceanic temperatures and carbon dioxide levels have risen significantly.
When carbon dioxide combines with water, a unique interaction occurs that results in an increasing concentration of hydrogen ions. As hydrogen levels increase, the pH or potential hydrogen, decreases resulting in a process known as Ocean Acidification.
Currently, our global oceans register collectively at about a pH of 8.1 on a logarithmic (exponential) scale that ranges from most acidic (0) to most basic or alkaline (14). As more and more hydrogen ions become available, scientists predict that the ocean’s pH will lower to approximately 7.8 by the end of the century. These changes and their impacts are already being witnessed.
Eight tightly swirled shells lined up in successive states of dissolving. Representing impacts of acidification on calcium carbonate. Image in black and white.
Calcium carbonate is the substance that makes up animal’s protective shells. Akin to mixing baking soda with vinegar, it is susceptible to acidifying seas. Lower pH can be detrimental to the development and formation of shells, impacting the survival of many species throughout the marine ecosystem.
As is with humans, many organisms have adapted to a specific pH range to maintain normal body processes necessary for life. Ocean acidification threatens this delicate balance and will have far reaching consequences for marine species and the global populace that relies on them.
Underwater image of an assortment of spiny sea urchins, long mussels, volcano-like barnacles, and small shells. Image in black and white.
Monitoring for the Future
Much of what we currently understand about ocean acidification comes from large, open ocean environments or simulated laboratory experiments. We know little about how pH will change in the highly unpredictable conditions of the intertidal zone. More importantly, we aren’t sure what any changes might mean for the exceptionally diverse and sensitive marine organisms that reside there.
From the small, abundant hermit crabs that skuttle about as you and your family explore the tidepools to the critically endangered black abalone that represent a mere fraction of their once expansive population, there is a vast number of shelled, intertidal organisms. Each hangs in the balance of what we know and what we do not.
Two segmented marine snails that have bore into the rock face. Image in black and white.
Four small marine snails that have bore into the rock face. Image in black and white.
A large abalone shell covered in leafy algal turf sitting on a rock. Image in black and white.
“With monitoring data dating back to the early 1980s, we now have a substantial record of the population trends for many important species in the rocky intertidal. However, in the absence of critical environmental information like ocean temperature and pH, it can be a daunting task to make sense of these trends. This work helps to fill those gaps in information allowing us to better understand the potential drivers of change and guide our management decisions to better conserve our impaired rocky intertidal ecosystems.”
Stephen Whitaker, Chief of Natural Resources - Channel Islands National Park
As stewards of over 80 marine-based parks and with their long-term monitoring programs already in place, the National Park Service was well positioned to begin exploring the impacts of ocean acidification in the intertidal ecosystem—starting at Olympic National Park—but quickly extending beyond.
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Olympic National Park
Port Angeles, Washington
With the goals of establishing a baseline data set for ocean acidification and assessing current and predicted vulnerabilities of intertidal communities to its impacts, ocean acidification monitoring began on the Olympic Peninsula in 2010. State-of-the-art sensors were installed in large tidal pools to regularly measure for pH, temperature, dissolved oxygen, and salinity. In combination, each of these metrics provides a more holistic picture of what pH looks like in the rocky intertidal zone and how it might change in the future. From there, additional sensors were placed across the Salish Sea in 2015 at San Juan Island Historical Park.
At the farthest edge of the Point Loma peninsula in San Diego, California, lies a small 1.5 mile stretch of protected shore. Considered one of the most heavily urbanized coastlines in the United States, Cabrillo National Monument simultaneously maintains one of the most intact rocky intertidal habitats on the mainland of Southern California. In 2016, NPS biologists collaborated to expand the ocean acidification monitoring program southward and install instrumentation in a protected area of the intertidal off limits to the over one million visitors that enjoy the park every year. Due to its unique preservation status, this space maintains one of the largest diversities of marine invertebrates on the southern coast. As a result, it is critical to our understanding of ocean acidification impacts in the intertidal ecosystem. Like their counterparts to the north, the instruments are checked quarterly and data is downloaded for review.
In 2017, Channel Islands National Park joined the monitoring effort. The marine area of the park spans over 149,000 water acres and has been designated as a UNESCO International Biosphere Reserve and a State of California Area of Special Biological Significance. Known as the Galapagos of North America, the Channel Islands protect a considerable amount of marine biodiversity. They’re also particularly impacted by the oceanographic phenomena known as upwelling. Upwelling works to churn deep ocean water and bring it to the surface, a dynamic that researchers are working to understand in concert with changes in ocean pH. In conjunction with long-term monitoring data on trends in abundance and diversity of species, this information can be utilized in efforts to recognize impacts of changing ocean acidity on marine intertidal communities.
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Punta Mazo Nature Reserve
San Quintín Bay, Baja California
As with many consequences of climate change, ocean acidification does not recognize human-set boundaries. With this in mind, NPS researchers connected with sister organizations further south in the Baja California Peninsula to broaden monitoring efforts in 2018. Overseen by the Mexican conservation organization Terra Peninsular, the Punta Mazo Nature Reserve is a landscape unlike any other. The intertidal region of San Quintín Bay, where the reserve is located, has been formed on the striking coastline of volcanic rock. By expanding the network in this way, researchers can grasp a latitudinal snapshot of ocean acidification impacts across the entirety of the West Coast.
“To tackle big, globe-spanning issues like ocean acidification we need to think big - beyond our boundaries. While collaboration might start between neighbors, it needs to expand until the depth and scope of collaboration matches the scale of the issue at hand.
For over 100 years, the National Park Service has dutifully carried out the mission to preserve and protect the natural spaces and resources that we manage. By measuring the impacts of a changing ocean on the intertidal resources in our care, we have taken the critical first steps toward understanding how intertidal systems are responding and adapting to these and other stressors.
We must, however, continue to broaden our work alongside an even greater number of partners and agencies, if we want to push beyond monitoring and begin actively safeguarding these at-risk ecosystems.”
Dr. Keith Lombardo, Director - Southern California Research Learning Center
Two small crabs huddle together in a rocky crevice. Image in black and white.
An unbalanced ocean ecosystem presents a real and present threat to human and natural communities across the globe. We are just beginning to understand how ocean acidification and other related phenomena will impact our marine resources and the communities that rely on them. These monitoring efforts are merely one part of the puzzle.
What we do know for certain, is that our actions—the choices we make everyday—can make a difference. The National Park Service works earnestly to preserve and protect these beautiful places for the enjoyment of this and future generations, but we can’t do it alone. We challenge you to do your part in your local and global communities. From understanding and offsetting the impacts of your consumer choices to volunteering with organizations working towards change—we all can be a part of the solution.
