What does it take to design a healthy coastal ecosystem? How do you create an environment in which both wildlife and people can thrive?
Based on what we've learned working in the Salish Sea, SeaDoc has created a list of 10 principles that guide our work and that can guide anyone trying to bring a coastal ecosystem back to health. Our analysis was published in the peer-reviewed journal, EcoHealth.
Like other coastal zones around the world, the inland sea ecosystem of Washington (USA) and British Columbia (Canada), an area known as the Salish Sea, is changing under pressure from a growing human population, conversion of native forest and shoreline habitat to urban development, toxic contamination of sediments and species, and overharvest of resources.
While billions of dollars have been spent trying to restore other coastal ecosystems around the world, there still is no successful model for restoring estuarine or marine ecosystems like the Salish Sea.
Despite the lack of a guiding model, major ecological principles do exist that should be applied as people work to design the Salish Sea and other large marine ecosystems for the future.
1: Think ecosystem. Political boundaries are arbitrary
Just because an international border splits an ecosystem, that doesn’t mean it is observed by the fish and wildlife or physical processes that make up the ecosystem and it shouldn’t prevent the people on both sides of the border from working together.
Although there is a major Washington State effort to restore Puget Sound by the year 2020, the Puget Sound basin is only one half of a large and unified ecosystem, the Salish Sea. Efforts to restore Puget Sound will fail if they do not incorporate and integrate similar efforts on the Canadian side of the border.
The international political boundary separating the Puget Sound and Georgia Basin is invisible to marine fish and wildlife. Species listed as threatened or endangered under the US Endangered Species Act or the Canadian Species at Risk Act -- including Southern Resident killer whales, marbled murrelets, and some ecologically significant units or species of Pacific salmon -- traverse the boundary daily.
Oceanographic processes such as freshwater inflows and wind driven surface currents exchange biota, sediments and nutrients throughout the larger ecosystem. For example, the less saline, more buoyant Fraser River plume can be observed by satellite imagery flowing across the international boundary throughout the year and tidal oscillations move huge volumes of water across the border four times daily.
International, state, provincial, or tribal, political boundaries impede ecosystem restoration. Management of the iconic Pacific salmon is a striking example of the unique challenges created when ecosystem and political boundaries do not align. The migration patterns of the five species of Pacific salmon in this ecosystem create transboundary fishery regimes containing mixed stocks from numerous river systems of origin (some from USA and others from Canada).
In 1945, the United States and Canada implemented the first bilateral Pacific salmon-sharing agreement, followed by the 1985 Pacific Salmon Treaty. However, by 1997, as salmon stocks were declining, accusations from both sides about the interception and harvest of fish destined for the other country became so heated that the USA and Canada independently shifted their fishery regimes, foregoing all concerns about stock declines. These “salmon wars” ultimately culminated in a renewed salmon harvest agreement signed in 1999.
While the governments of Washington State and British Columbia signed an Environmental Cooperative Agreement in 1992 to work together on marine issues in the Salish Sea, the agreement is hampered by internal constraints imposed by tribal and federal laws. For instance, a 1974 court decision reaffirmed the treaties between the U.S. Federal Government and 19 tribes in Washington signed in 1885, and ruled that 17 tribes with usual and accustom fishing areas in Puget Sound have the right to 50% of the harvestable fish and shellfish resources. By contrast, in Canada the Federal Government regulates all tribal harvest.
"Thinking ecosystem" requires focusing restoration efforts from the start on all sides of the political border and finding mutually agreeable solutions among all levels of government. The principle worked in the design of the Mount Elgon Regional Ecosystem Conservation Program, a transboundary natural resource management program involving the republics of Kenya and Uganda, and will work for multi-national coastal ecosystems as well.
Focus on the ecosystem as its own legitimate entity can help prevent the past experiences where agreements made when resources were abundant quickly unraveled as those resources declined.
2: Account for ecosystem connectivity
When we think about our own health, we focus on all parts at the same time. Eating well is as important as exercising, which is just as important as getting enough sleep and stimulating our minds. We need do the same and think about all the parts when we design a healthy ecosystem too.
Ecosystems are more interconnected than most people appreciate. Citizens, scientists, managers and policy makers filter out these connections in order to focus on specific areas or species of interest, using compartmentalization to simplify the daunting challenges of managing complex systems.
Understanding the connectivity and linkages between seemingly unrelated species and ecosystems is key to successful restoration.
Like most ecosystems, the factors determining the fate of the Salish Sea extend hundreds of kilometers from the sea to the crest of the mountains that surround these waters. For example, the amount and configuration of impervious surfaces (e.g. concrete parking lots, roads) and harvested forests impact the biotic integrity of streams feeding into the Salish Sea, which in turn affects the health of the entire ecosystem.
Forest health impacts the abundance of the marbled murrelet, an endangered seabird that nests up to 50 miles inland in old growth forests, but spends the remaining 11.5 months of the year feeding at sea.
Intricate food webs can connect species across ecosystems. For example, gray whale abundance is linked to productivity in the Bering Sea and the abundance of migrating gray whales feeding in the Salish Sea could be important for the recovery of declining surf scoter populations.
Commerce and transportation are powerful non-biological forces that link the biota of Puget Sound to other ecosystems. For instance, in 2006-2007 Washington State and tribal fishermen harvested over 225 metric tons of sea cucumbers, the majority of which were exported to Asian markets. Increasing non-local demand for fisheries can potentially drive unsustainable harvest and hinder restoration. The robust shipping industry that links the Salish Sea to most of the world also is a source of invasive species that can threaten the integrity of biological communities.
Connectivity contributes to ecosystem functions. Understanding these intricacies is important for designing healthy ecosystems. For example, recent modeling in the Caribbean suggests that the mangrove-based ontogenetic migrations of parrotfish could, through a trophic cascade on macroalgae, enhance the recovery rate of midshelf Caribbean coral reefs from hurricanes. Consequently, preserving or replanting mangroves will improve Caribbean coral resiliency in the face of predicted increased hurricane frequency and intensity.
While it is tempting to filter out the apparent “noise” from other species and ecosystems, acknowledging and identifying key cross-species and cross-habitat connections are essential to understanding changes in the system and measuring performance.
3: Understand the food web
We read labels and pay attention to the food we eat because food is important and it connects us to the world. Who eats who or what also is important for ecosystems and understanding the food web is critical for helping us understand and design a healthy ecosystem.
Food webs represent complex trophic interactions among species: they can change seasonally and geographically. Although often simplified for communication purposes, food web linkages are complex, subtle and interactive. They play a major role in ecosystem connectivity as well as in ecosystem resiliency and capacity for renewal.
A working food web model is a powerful tool for managing ecosystems. Around the world, traditional harvest management tools, such as maximum sustainable yield models, focus on how many individuals can be harvested sustainably by humans.
However, the models fail to take into account the full range of trophic interactions and trophic needs. For example, an acceptable salmon harvest level is designed to ensure that sufficient individuals are left to spawn in order to maintain viability of the salmon run into the future. What it fails to account for are the needs of other species dependent on the same salmon run, i.e. those species that prey on salmon or those species that are salmon prey.
Determining the impact of human-harvested salmon on killer whales, eagles or any of the other 136 vertebrate species that rely on salmon or salmon carcasses has proved elusive. Yet it has important biological and policy consequences. For instance, an important factor in listing Southern Resident killer whales as threatened under the U.S. Endangered Species Act was the decline in its primary prey, salmon.
Food webs can be used to identify priority or key species in biological communities. Measures taken to protect them and their habitats benefit the entire ecosystem. For instance, Pacific sand lance and surf smelt are key forage fish for some Puget Sound birds and mammals. Locating and protecting their intertidal gravel-sand spawning beaches and associated upland riparian habitats assures food supplies for many species. Human alteration of the shoreline can change environmental conditions of these beaches and halve egg survival resulting in “bottom up” impacts on the ecosystem through the food web.
Knowledge of food web dynamics allows managers to monitor movement of contaminants in the ecosystem and the effects of the toxins on species composition, abundance, diversity and ultimately the food web itself. Bioaccumulation of toxins has been shown to impact multiple species in many ways; from the immunologic health of harbor seals to the density and species richness of Phoxocephalid amphipods.
4: Avoid fragmentation
Breaking up the working parts of our ecosystem is like separating the working parts of an engine, it prevents it from working properly. Designing healthy ecosystems requires that we keep habitats connected.
Human activities that break otherwise contiguous habitat (land and seascapes) into smaller pieces fragment ecosystems, reduce their ecological integrity, and threaten their capacity to renew themselves.
Habitat is the place where species interact and form complex communities. Habitat size is directly linked to population size and the nature of species interactions. All species require a minimum number and density of individuals to persist, thus they also require a minimum amount of suitable habitat.
For most species, habitat configuration is also important. When habitats are fragmented and shrink below the size required to support a minimum viable population or are significantly modified or disturbed, a sequence of events begins that can end with species extinction.
At low densities (associated with small habitats) individuals may be unable to find mates. For example, this is particularly critical for benthic animals with little mobility such as abalone and some rockfish species. Small populations are more susceptible to extinction by extreme natural events and are more likely to lack the genetic diversity needed to adapt to changing physical and biological conditions such as climate change or competition from invasive species.
Unlike the terrestrial environment, where habitat size is visible and easily monitored, fragmentation in the marine environment is notoriously hard to study. Thus it has received far less attention.
There are many ways in which people inadvertently fragment marine habitats. For instance, seafloor trawling can have devastating effects on the seafloor and result in isolated “islands” of unaltered submarine habitats too small to maintain viable populations.
Pelagic species and large mammals can experience habitat fragmentation through fisheries and reserve policies. For instance, reserve areas may be too small to contain the necessary food resources to sustain populations of marine mammals.
Where the land meets the ocean, anthropogenic shoreline alterations can fragment the nearshore marine habitat and reduce productivity. For example, terrestrial insects falling into nearshore marine water are an important food source for migrating juvenile salmonids and the removal of overhanging shoreline vegetation reduces this important food source. Additionally, removal of overhanging shoreline vegetation can alter the microclimate of beaches and reduce their suitability for incubating eggs of intertidal spawning fish.
Some tools used to address ecosystem fragmentation in terrestrial ecosystems also could be used to address ecosystem fragmentation in coastal ecosystems. Fragmentation through land subdivision and the loss of large-scale dynamic processes such as wildlife migrations and fire was identified as the major threat to the world’s grassland ecosystems. Cultural exchange between Maasai pastoralists from Kenya and ranchers from the United States helped address these fragmentation threats by speeding up understanding and adaptation.
5: Respect ecosystem integrity
Keeping all the parts of an ecosystem and not adding new ones is a critical part of having a healthy working ecosystem. Taking actions that help to keep important parts (like whales or certain habitats) and not introducing new parts (like non-native species) is part of designing a healthy ecosystem.
Intact ecosystems are more than the sum of their parts. Processes and forces that bind the parts into a system produce synergies and properties that the individual parts do not possess when simply collected together.
Ecological integrity, in which a system has all its parts and no "extra" ones, is a hallmark of environmental health. An intact ecosystem has a complete suite of species, and a full range of size and age classes of each component species.
Ignoring the ecological integrity and the power of biological interdependence in marine systems has been catastrophic. Historically, fishery practices targeted predators and preferentially removed old, large organisms (those with the greatest reproductive capacities), while relying on smaller, rapidly growing and barely reproducing younger animals for replenishment. As a consequence, fishery collapses became widespread. But the ecosystem-wide impacts were just as disastrous. Because predators mediate competition among prey species and help assure that a few, fit individuals of all kinds survive to produce another generation, such single-species management strategies not only doomed targeted populations to death spirals, but also triggered trophic cascades with ecological effects that persisted for decades and involved hundreds of species.
Adding, or introducing, invasive species, toxic materials, and pathogens also reduces ecological integrity. In the Salish Sea, non-native species like the purple varnish clam likely were introduced in ballast water. Other species, like the Japanese seaweed Sargassum muticum, likely were introduced with the intentionally introduced Pacific oyster, and now compete with native kelp, impacting benthic subtidal communities.
The ocean, a historical out-of-sight-out-of-mind dumping ground for industrial waste, now bears the burden of many metric tons of organochlorines and other persistent organic pollutants that have bioaccumulated in the food chain and impacted the health of top predators. The Salish Sea’s resident and transient killer whales are considered some of the most contaminated cetaceans in the world.
6: Support nature’s resilience
How many punches can a person take before they fall? It depends on how much sleep they’ve had, what physical condition they are in, how hard the punches are, and a suite of other factors. Like people, we can and should do things that enable our ecosystems to take more punches, while trying to reduce the punches we deal it.
A resilient ecosystem can rebound after a disturbance. Resilience is a measure of health and indicates how much stress a system can absorb before it permanently changes into an alternative state or collapses.
While resilience is essential in a healthy ecosystem, it is frequently ignored in conservation planning. This is because it is hard to measure, and often only recognized once the system is on the verge of collapse.
Biological communities have several natural attributes that make them resilient in the face of change and disturbance. For example, the presence of a keystone species determines persistence and stability. In the Salish Sea’s rocky intertidal zone, the sea star Pisaster ochraeus is essential to maintaining a highly diverse and stable community. In their absence, a monoculture of mussels occurs.
Other communities lacking a keystone species rely on a suite of interacting organisms to build resilience. Genetic diversity has also been shown to increase ecosystem resilience in seagrass communities stressed by elevated temperatures.
Human actions can inadvertently disrupt the factors that allow ecosystems to respond and persist in the face of change. Removal of a keystone species can lead to ecosystem collapse. Overfishing can have a detrimental impact on resilience: twenty years of data from reserve versus fished sites showed that reserves maintained a greater complement of species and were consistently able to withstand and rebound from extreme, but not unusual, environmental conditions such as El Niño years. Fished sites had fewer species and communities. Habitats within the fished sites frequently collapsed during El Niño events.
The principle of building ecosystem resilience is gaining ground. There is a complex systems approach for sustaining and repairing marine ecosystems, linking ecological resilience to governance structures, economics and society. Previously, some scientists have found that corals in the Indo-Pacific and elsewhere are showing signs of resilience in their ability to adapt to climate change and have called for international integration of management strategies that support reef resilience. Since then, toolkits on effective ways to build reef resilience as an integral part of designing healthy marine ecosystems have been developed and are being applied worldwide on reefs from India to Africa, the Caribbean and the Americas.
7: Value nature: it’s money in your pocket
Fish and wildlife are a source of income. People pay to watch them or harvest them, and the ecosystem itself helps us by filtering toxins and preventing flooding. When you think of the ecosystem like a bank account, putting money into to improve it is a no-brainer; it's like adding capital to your account.
Economics is the allocation of limited resources among alternative, competing ends. It's about what people want, and what they are willing to give up in exchange.
Human well-being is derived from access to—and often the marketing of—essential ecological goods and services provided by ecosystems. These include fossil fuels, minerals, wood, fish, meat, edible plants, watchable wildlife, biofiltration of contaminants, and a multitude of other ecological "inputs." While higher values of waterfront properties are considered luxuries, most ecological goods and services are considered basic needs for human survival.
Despite the complexities of economic globalization, healthy ecosystems support economic prosperity and well-being. The Salish Sea provides the people who live in the region with abundant natural capital which contributes substantially to the financial prosperity of the region.
In Washington alone, marine fish and invertebrates support commercial fisheries worth $3.2 billion a year; the ports of Seattle and Tacoma enable over $70 billion in international trade; and on the water activities such as sailing, kayaking, whale-watching, and SCUBA diving generate 80% of all dollars spent on tourism and recreation in the state every year.
Healthy ecosystems support economic prosperity. Unhealthy systems cost money to repair and cost money in lost opportunities to benefit from the natural capital. Overharvesting, pollution, and loss of wild habitat reduce the quality and quantity of ecosystem services and ultimately the economic potential of a region. For example, fecal coliform contamination of nearshore waters closed a third of Washington’s $97 million shellfish beds to harvest in one year alone.
In the Salish Sea, ecosystem services provided by higher trophic species like salmon and killer whales, which generally disappear before those provided by species lower in the food chain, are decreasing. The cumulative economic and ecosystem services losses associated with the depletion of these higher trophic species is incalculable, but likely astronomical.
When appropriately balanced, ecosystem services can be used to simultaneously advance conservation and human needs, as has been shown with projects like Quito, Equador’s Water Fund, China’s Sloping Lands Program, Kenya’s Il’Ngwesi Ecolodge, and Namibia’s Conservancy Program.
A healthy Salish Sea that provides services such as plentiful and safe fish and shellfish, clean water, and natural resource-dependent industries is money in our pockets. Ecosystem services provide revenue from the marine-based industries that are the lifeblood of the region’s economy, and mean less spent on major repairs to reverse ecological damage.
Decision-makers and citizens working to restore ecosystems around the world need to grasp nature’s economic benefits or they will grossly underestimate the full benefits of a restored ecosystem while overestimating the relative costs of restoring it.
8: Watch wildlife health
Within an ecosystem, wild animals and humans share many diseases and are susceptible to many of the same toxins. Studying diseases and contaminants in wildlife help us to better protect them and help prevent disease in people.
Disease in marine wildlife can serve as a sentinel for human health. Animals, particularly wildlife, are thought to be the source of over 70% of all emerging infections. A burgeoning human population, increased travel opportunities, booming commerce, frequent animal relocations, and expanding aquaculture increase human exposure to zoonotic diseases from marine wildlife.
Blooms of the phytoplankton Pseudo-nitzschia have caused closures of recreational, commercial, and tribal subsistence shellfish harvest in the Salish Sea. These organisms produce domoic acid, a biotoxin known to cause seizures and death in marine mammals and amnesic shellfish disease in humans. Marine mammals are exposed by eating fish that have consumed domoic acid. Exposed animals often will strand on beaches and can serve as an early warning indicator for potential exposure of humans through shellfish consumption, thereby allowing managers to close shellfish harvesting areas to protect human health.
Discovering that the feline parasite Toxoplasma gondii infected marine wildlife alerted people to the fact that raw shellfish consumption also could be a route of exposure for humans. If a pregnant woman becomes infected with this parasite the parasite can infect the fetus, leading to mental retardation, seizures, blindness and death in children. Interestingly, this cat parasite has been discovered to infect marine wildlife such as sea otters, marine-foraging river otters and harbor seals.
It is believed that marine wildlife are exposed to T. gondii when cats shed the infective stage (oocyst) in feces, which is then transported by freshwater run-off into the marine ecosystem. Increased numbers of domestic and feral cats and their associated feces as well as modifications in freshwater run-off have probably increased marine mammal exposure to this parasite. Because shellfish can concentrate the infective T. gondii oocysts, humans, like marine mammals, also are at risk for exposure by eating uncooked shellfish.
Human, wildlife and ecosystem health are intimately connected. Understanding and monitoring diseases in both groups will help to identify where and when a stressed ecosystem is contributing to increased disease in people and wildlife and how the ecosystem can be redesigned. In the Salish Sea region high-quality public health programs exist, but efforts to monitor and understand marine wildlife health in both countries are limited and not well linked to human health networks.
9: Plan for extremes
Knowing that the daily average temperature is 71°F has little meaning if the daily temperature ranges from 115°F during the day and 27°F at night. We all know the perils of walking across a river with an "average depth of four feet." Planning for extreme ecosystem events (like floods and storms), and not just the average, is prudent.
High variation and diversity are key characteristics of living systems, and averages can mislead people seeking to understand and manage nature.
For instance, fisheries management based on “average abundance” will fail to account for poor years, and is likely to drive the species extinct. Yet resource users often will prefer to manage for the average.
A major discovery of environmental science in the 20th Century was the ecological significance of "natural extreme events." Many people still view these kinds of events only as disasters that wreak havoc on society and cause humanitarian tragedies. The emergence of disturbance ecology illustrated the critical roles that rare extreme events like wildfires, hurricanes, droughts, floods, and El Niño Southern Oscillation events have played in sustaining biodiversity and ecological integrity in oceans.
As citizens, scientists and decision makers begin to envision a restored Salish Sea, that vision must include policies, laws, and management actions that account for extreme but natural events.
10: Share the knowledge
Humans are integral parts of ecosystems. Citizens who understand that their own physical, mental, and economic well-being is intimately connected to the health of the ecosystem are more likely to support and engage in ecosystem restoration.
While the people of the Salish Sea are believed to value their ecosystem, in reality there currently seems to be little support for restoring it. Despite overwhelming scientific evidence about declines in the health of Puget Sound, a 2006 poll found that only 8% of respondents felt the condition of the environment was the most important problem facing people in the Puget Sound region. Widespread public education about the issues and what is at stake could build a connection to the ecosystem and rally support for its restoration.
But public support alone will not restore the Salish Sea. Political leadership and funding are equally essential. In the Florida Everglades, citizens have expressed their desire for ecosystem restoration to their political representatives and the representatives themselves are charged with providing the long-term support and funding required for restoration. Only an educated and dedicated political leadership demonstrating vision and stamina will keep a long-term focus on restoring ecosystems in the face of numerous short-term competing interests.
Marine resources of the Salish Sea are managed by multiple local, state, federal, tribal, and national governments. The common bonds among these myriad of governance agencies is the human community they serve and the ecosystem they seek to sustain as healthy and productive. Scientists play a unique role in linking citizens, politicians and nature. By sharing knowledge they can help inform citizens and decision makers so that actions are science-based and take account of the key factors that will help ensure success.
The issues people face in designing a healthy Salish Sea are not unique. Human communities worldwide gather in ever increasing numbers at the coast, adding pressure on the ecosystem’s goods and services.
Human use threatens the sustainability of the natural, social, and economic values that attracted them to the coast in the first place. Ocean and aquatic systems generate more than 60% of the world’s ecosystem services. Human communities ignore or degrade these services and their value at their own peril.
These ten ecological principles can guide people in designing local actions that will have persistent global impacts on environmental quality and human health and well-being. These science-based principles will be most effective in informing political processes if they are communicated to citizens and policy makers in ways that are both tangible and memorable. Societies around the world that have cultural, religious, and economic differences are working to design healthy ecosystems. Expressing ecological principles in ways that might capture the attention and interest of local communities will benefit place-based education and conservation efforts.
In summary, issues at political boundaries can be resolved with cooperation, while nature’s boundaries are immutable dynamic connections that cannot be negotiated or changed by policy: think ecosystem.
Great thinkers and philosophers from Henry David Thoreau to Edward O. Wilson have espoused the global interdependence of people and other parts of nature that is inescapable in designing sustainable communities: account for ecosystem connectivity.
Knowing how plants and animals are related to each other by their diets is a practical way to visualize connectivity, interdependence, and system integrity and helps predict how nature will respond to stresses: understand your food web.
Habitats of adequate size and quality to support high levels of biodiversity are critical characteristics of healthy ecosystems: avoid fragmentation.
Loss of integrity threatens nature’s stability, beauty, and capacity for self-renewal, but integrity can be rebuilt and sustained by design: respect ecosystem integrity.
While healthy ecosystems have tremendous capacity for self-renewal, resilience can be overwhelmed by collective human activities. Again, resilience can be restored by people, by design.
Healthy ecosystems are money in your pocket because they save on repair costs and deliver essential goods and services: value nature.
Diseases in marine animals are closely linked to human health and can provide early warnings as sentinels of ecosystem stress: watch wildlife health.
Nature is variable and rarely average. Extreme natural events test fitness, mediate competition, and assure diverse opportunities: plan for extremes.
Finally, people matter from grassroots to government and little will happen without educating and incorporating humans at every level into designing a healthy ecosystem for the future: share the knowledge.
How you can get involved in healing the Salish Sea
If you agree our top ten principles provide an important framework for protecting and healing the Salish Sea, please join our efforts by becoming a donor.
Your donations go to support our programs to keep the Salish Sea healthy for wildlife and for people.