Biodiversity: More Is Not Always Better

Happy Biodiversity Day! Most of us have heard the word biodiversity being tossed around as an important subject that requires our attention, but why is biodiversity so important? This topic is much more difficult to address than you might think. Biodiversity refers to the level of variation of life within an ecosystem. Plants and animals have everything they need to live sustainably together in an ecosystem that has healthy biodiversity. Although biodiversity is a crucial subject in restoration science, there can be a misunderstanding that more biodiversity is always better. Researchers are finding that the types of species in an ecosystem are just as important as the number of species and more isn’t always better. Save The Bay confronts this issue of biodiversity every time we design a habitat restoration plan for tidal wetland transition zones within the San Francisco Bay.

biodiversity
Biodiverse restored transition zone habitat at Eden Landing with invasive monoculture of mustard on the other side of the fence.

To better understand this idea that more biodiversity isn’t always better when designing habitat restoration plans, let’s first consider what habitat restoration means and what’s being restored. Effective environmental restoration will restore ecosystem function. Ecosystem function involves biological, geochemical, and physical processes that vary between systems, but maintain a specific balance within each ecosystem, and that balance is delicate. Plants, animals, water, and earth all contribute to how ecosystems function, and when one of those contributions change, so do the others. Those changes not only displace the effectiveness and sustainability of food webs (Zedler and Kercher, 2004) but they also affect ecosystem services that humans rely on, such as food, water, medicine, transportation, employment, inspiration, shelter, and protection… to name a few. For example, an important ecosystem service that wetlands offer humans is their role as breeding and nursery grounds for economically important fish species, including the Pacific anchovy, California halibut, rainbow trout, and Chinook salmon. Tidal wetlands also provide important feeding and stopping grounds for migrating birds, which not only contribute to maintaining healthy populations of those economically important fish species, but also help to maintain healthy native insect and rodent populations.

Once researchers learned the importance of biodiversity and discovered it was diminishing, so began the mission to determine the cause for this great loss. Many factors have contributed to our worldwide decrease in biodiversity, and tidal wetlands are among the greatest victims. 90% of the San Francisco Bay wetlands have been destroyed due to bayfill, contamination, industrial use, and fragmentation. This hardship makes life difficult (if not impossible) for the San Francisco native species that depend on a healthy wetland habitat, and therefore, the wetlands have developed a decreased immunity to invasions by non-native species. Invasive non-native species thrive when conditions are difficult for the natives and they often completely take over entire ecosystems if left unchecked. Not all non-native species are invasive, just the ones that demolish the native diversity. And San Francisco Bay has the greatest number of invasive species anywhere in the western hemisphere.

As environmental scientists learned more about the intricacies of biodiversity, it became apparent that diversity should reflect the needs of the resident flora and fauna, since both are so interconnected. This observation may indicate that, while biodiversity offers the benefit of ecosystem stability, restoring an ecosystem to a sustainable functioning state should be the ultimate goal. So, rather than focusing on the blanket idea of increasing biodiversity across the board, researchers and practitioners have begun to implement the idea of restoring the biodiversity that has been lost in a particular area. That means that if a particular ecosystem historically was home to only a few species, practitioners are better off trying to restore the functions that those few species provided to that area, which is the entire point of restoration. Save The Bay works hard to understand and recognize the specific ecosystem functions at each of our sites and the specific native plant species that are capable of supporting those functions. Join us on one of our community-based restoration programs to ensure that the flowers have bees for pollination, the birds have a place to perch and nest, and the salt marsh harvest mouse has sufficient refugia during high tide.

Reference:
Zedler, JB and Kercher S. (2004). Causes and consequences of invasive plants in wetlands: Opportunities,
opportunists, and outcomes. Critical Reviews in Plant Sciences. 23(5):431-452.

Weekly Roundup | April 19, 2013

newspaperCheck out this week’s Weekly Roundup for breaking news affecting San Francisco Bay.

Slate 4/19/13
Seven Spectacular Places Saved by the Environmental Movement
The first Earth Day, in 1970, was inspired by anger. The nation was a mess. Four million gallons of oil from a blown offshore well were smearing California beaches. Flames leapt from the surface of Ohio’s Cuyahoga River. Bald eagles, our national symbol, had been winnowed by hunting and chemical pollution to a few hundred breeding pairs in the lower 48 states. It’s no wonder that 20 million people took to the streets.
Read more >>

Tri-City Voice 4/16/13
Beyond Earth Day
Picking up a few empty bottles or planting some trees Earth Day morning has become regular duty for any Bay Area resident with a conscience. The trio below just kept going after “E Day” and shows how average people can make a big difference in our place by the Bay.  Steve Haas started volunteering with Save the Bay about four years ago. Save The Bay is a nonprofit organization dedicated to preserving San Francisco Bay and has been doing it for over 50 years. The management consulting and software development professional retired about two years ago and spends more and more of his free time with Save the Bay and other environmental organizations, getting out once or twice a month to assist projects at Eden Landing in Hayward and other locations on the Peninsula. The projects involve removing invasive plants, planting native species, mulching, and watering. Haas says he enjoys all of these, but especially removing the invasive plants.
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San Francisco Bay Guardian Online 4/16/13
Warriors Arena proposal rouses supporters and opponents
Rival teams have formed in the last week to support and oppose the proposed Warriors Arena at Piers 30-32 as the California Legislature considers a new bill to approve the project, a new design is about to be released, and a trio of San Francisco agencies prepares to hold informational hearings.  Fresh off the collapse of two of the city’s biggest development deals, Mayor Ed Lee and his allies are pushing hard to lock in what he hopes will be his “legacy project.” A new group of local business leaders calling itself Warriors on the Waterfront held a rally on the steps of City Hall today, emphasizing the project’s job creation, community partnerships, and revitalization of a dilapidated stretch of waterfront.
Read More>>

San Jose Mercury News 4/13/13
Family of beavers found living in downtown San Jose
A family of beavers has moved into Silicon Valley, taking up residence along the Guadalupe River in the heart of downtown San Jose.  The discovery of the three semiaquatic rodents — famous for their flat tails, brown coats and huge teeth — a few hundred yards from freeways, tall office buildings and the HP Pavilion represents the most high-profile Bay Area sighting since a beaver family settled in Martinez in 2006. The discovery of those beavers sparked national headlines when city leaders at first tried to remove them and then backed down after public outcry.  The appearance of the furry mammals in downtown San Jose is believed to be the first in 150 years.
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San Mateo Daily Journal 4/17/13
San Mateo moves to ban plastic bags, polystyrene
The San Mateo City Council voted unanimously to support a reusable bag ordinance, completing the regional effort in San Mateo County and parts of Santa Clara County to reduce litter.  The amendment to city code promotes the use of reusable bags as an alternative to single-use plastic and paper bags and mirrors a countywide effort.  The City Council also voted Monday night to support the polystyrene ban which will ban the use of polystyrene in restaurants and delicatessens.  Adoption of both ordinances is expected May 6 with implementation beginning June 6 in San Mateo.  San Mateo County, along with many other cities will implement the reusable bag ordinance Earth Day, April 22.
Read More>>

Oroville Mercury-Register 4/15/13
Legal action threatened if Chico adopts plastic bag ban
An attorney for the Save The Plastic Bag Coalition is threatening legal action if the city of Chico moves forward with its proposed ban on plastic bags.  The City Council is set to consider an ordinance Tuesday that would prohibit specified stores from providing single-use plastic carryout bags and require a charge for the provision of single-use recyclable paper bags. The ban is slated to take effect next Jan. 1, after an extensive educational campaign.  Attorney Stephen L. Joseph said the Los Angeles-based Save The Plastic Bag Coalition objects to the ordinance’s adoption without prior preparation and certification of an environmental impact report. In an email to the city, he said the coalition would file a petition in court for writ of mandate if the document is not prepared and request the court invalidate the ordinance.
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Marin Independent Journal 4/13/13
Environmental group proposes hybrid levees for Marin, other bayside counties as sea rises
Fortifying the bay’s shoreline with levees fronted by restored tidal marshes is a cheaper, more aesthetic and ecologically sensitive way to protect Marin and other bayside counties from sea level rise, according to a new report by a Bay Area environmental group.  The Bay Institute’s report — the subject of a panel discussion earlier this month in San Francisco — proposes restoring tidal marshes with sediment from local flood control channels and irrigating the marshes with treated wastewater. The plan also calls for “horizontal levees” that are a hybrid of traditional earthen levees and restored marshes. The conclusion was based partly on research done in the lower Corte Madera Creek watershed.
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King Tides Foreshadow Rising Seas

A man rides his bike slowly along the flooded bike path at Bothin Marsh, Marin, CA. The flooding is the result of the King Tides this past week.

Due to the slow but steady nature of ocean expansion, sea level rise has a tendency to be dismissed as a far-off predicament, not as an immediate threat. But with seas expected to rise 16 inches in the Bay Area by 2050, flooding 180,000 acres of coastline, the issue is now at our doorstep. Literally.

Last Thursday, sea levels peaked at over 10 feet in some places in the Bay Area during the highest King Tides event of 2012. The tides last week offered us a glimpse into the future of the California coastline: closing roads, flooding parking lots, and threatening to overwhelm levees from Marin to Santa Clara Counties.

A quarterly occurrence that reaches far back in history, the ultra-high King Tides are the result of a strong gravitational pull exerted by the Sun and the Moon – not climate change. But scientists say they offer important insight of how rising sea levels will impact coastal regions in years to come.

The combination of rapidly melting ice sheets and the thermal expansion of the ocean as it absorbs atmospheric and land-generated heat places sea level rise on an unstoppable trajectory that could raise the sea 16 feet in 300 years. Since experts agree that the reversal of rising seas is not possible, the risk for low-lying coastal areas will only increase. In the Bay Area, 81 schools, 11 fire stations, 9 police stations, and 42 healthcare facilities will be underwater or exposed to high flood events by 2100, when seas are expected to rise by 55-inches. Additionally, an estimated 270,000 people in the Bay will be at risk if no adaptive measures are taken – a 98 percent increase of those who are currently at risk.

Our approach to sea level rise must not mimic our approach to one-time natural disasters, such as hurricanes or earthquakes, in which we can recover and rebuild. Instead, the permanence of sea rise calls for a focus on adaption. It is more important than ever to propose plans to avoid the potential disaster of rising waters. One of the best solutions? Tidal marshland.

Tidal marsh and wetland habitat act as sponges during high tides, storm surges, and river flooding. They work to attenuate wave action that contributes to erosion. Since 40 percent of California’s land drains to the San Francisco Bay – contributing to longer-lasting flood events – wetlands have the substantial and crucial task of soaking up water from both land and sea.

Action now to protect and restore the Bay’s wetlands is essential and will help mitigate the impacts of climate change.

Many Bay Area residents are becoming part of the solution by volunteering their time to restore these protective marshes. Sign-up to volunteer with Save The Bay’s winter planting season!

Beyond the Parking Lot: Finding Peace in the Tidal Marsh

Eden Landing
This beautiful marsh is tucked behind the urban landscape in Hayward.

If someone had told me before I visited Hayward’s Eden Landing, that I’d see dozens of graceful white birds swooping over the marsh, or that a feeling of complete peace would wash over me once I stepped onto the levee, I never would have believed them.

As a San Franciscan who avoids freeways whenever possible, I’d never even been to Hayward before my first field experience as a new Save The Bay employee. All of my prior experience with wetlands had been in areas close to heavily populated urban areas, and well-used by the public, such as the Berkeley Marina. I didn’t know what to expect.

When I first turned off the freeway and began to make my way past the shopping centers and dense housing developments toward Save The Bay’s restoration site at Eden Landing, I have to admit I wasn’t expecting to experience beauty or peace. The area is both industrial and heavily residential. There didn’t seem to be space for nature. To my surprise, as I drove into the parking lot, and saw the Bay and its wetlands tucked away behind the homes, it was easy to leave the built world behind. I joined the group of Safeway employee volunteers in the park adjacent to the site for a quick orientation. Our job that day was to remove invasive plants to give the native plants room to grow. As we walked out onto the levee, the quiet was palpable despite the chattering volunteers.

Eden Landing in Hayward
The Bay literally sits in the backyard of Hayward residents.

We spent the morning scraping up the shallow-rooted slenderleaf iceplant (a plant that Seth Chanin, our Restoration Program Manager, describes as “plants with glistening vampire skin”) and pulling Russian thistle out of ground, concentrating on areas where the invasive plants were crowding out the pickleweed, California sage, salt marsh baccharis, and California goldenrod. These native plants provide important habitat for endangered species such as the salt marsh harvest mouse and California clapper rail. As quickly as the invasive weeds grow, it seems like a losing battle at first glance, but once the natives gain a foothold, they’ll do their own work to crowd out the invasive species.

One of my responsibilities in my new job is to explain to the media and the public why the work we do to restore our wetlands for people and wildlife is so important. Healthy wetlands are crucial for Bay habitats to thrive. But that’s not all. They also provide an unexpected source of quiet and stillness for humans to enjoy. A bit of wild nature in the midst of densely populated communities. Something I, for one, know that I need in order to thrive in my urban habitat.