News

Can Seawalls Save Us?

Huge coastal barriers could protect the world’s cities. But they’ll have unexpected costs.

There are many kinds of coastal protection. Some of the most effective are entirely natural. Marshes, mangroves, and even sandy beaches can absorb the destructive power of waves, helping to soak up water and energy that would otherwise wreak havoc. Engineers can fortify a shoreline by replenishing lost sand, or by adding rock, wood, or concrete. It’s also possible to augment the shore. A rock pile that parallels the coast, shielding the beach from waves, is called a breakwater. A pile that juts out to sea, trapping sand on one side, is called a groin. All of these measures are already widely used on coastlines around the world.

Hard seawalls may be the bluntest instrument in coastal engineering. Typically, they are made from concrete, stone, wood, or metal, and rise vertically from the shore. But a wave that strikes a seawall never breaks and dissipates, as it would on a beach; instead, it bounces off like an echo, its destructive force intact. In the end, the flow of water and sediment is a zero-sum game. For a wave to spare one place, it has to strike another; for sand to accumulate somewhere, it has to wash away from somewhere else.

When I ran these critiques of coastal protection by Rachel Gittman, a marine ecologist at East Carolina University, she offered another reason to worry about seawalls. Natural habitats already serve as powerful buffers against flooding, she said. They absorb water and energy; this is why marsh and mangrove restoration is often the best way to protect a coast. By contrast, when coastal communities wall off the shoreline, they tend to trap ecosystems between the water and the wall, causing a process called coastal squeeze. “It can be a slow drowning of those habitats,” she told me. When they disappear, we may be more vulnerable than when we started.

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How much do you know about Humboldt Bay Oysters?

On this week's EcoNews Report, Jen Kalt of Humboldt Waterkeeper interviews Sebastian Elrite of AquaRodeo Farms and Humboldt Bay Provisions to learn about Humboldt Bay oysters. Sebastian tells us all about how they are grown, why they're good for you, the importance of water quality, and how ocean acidification has led to a boom in the local oyster "seed" industry.

Tune in at this link or wherever you get podcasts!

Pay attention as offshore wind is developed

As a 20-year Manila resident and a member of the Peninsula Community Collaborative (PCC), I feel the winds of change blowing and am paying close attention to the offshore wind projects slated to come to Humboldt Bay.

Humboldt Bay and its offshore waters are becoming an integral part in the reduction of our reliance on fossil fuels. Currently, our harbor district is in negotiations with Crowley, a logistics and maritime service company based out of Jacksonville, Florida, to develop land in Samoa into a marine terminal. This port will be an industrial manufacturing plant that builds and ships out various components of offshore wind turbines. Wind components will eventually be shipped out to wind energy farms off of Humboldt shores and throughout the coasts of California and Oregon.

Living on the peninsula means living within the most amazing ocean, bay and dune ecosystems. I am lucky enough to walk directly to the beach and sometimes not see another person for hours. It is beautiful, peaceful, accessible, and unique. Other folks fish, surf, kayak, and otherwise enjoy these public spaces. As a lifelong environmentalist, I support the transition to renewable energy sources, but I also believe it is so important to keep this landscape and community safe during development.

While developing a port in beautiful Humboldt Bay, it is essential and appropriate to expect commitments from the developers that stand to profit from the new industry. Even the most “green” companies have the potential to cause harm and exploit the people, land, and resources of a community. Now is the time to lay out expectations of how we want Crowley to integrate into the Humboldt region. While I do not expect them to resolve all the historic challenges of our community, I expect them to participate immediately in the ongoing efforts to address needed improvements, as well as mitigate potential harms from the construction and functions of the port.

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Humboldt Bay offshore wind terminal sees $8.6 million investment

U.S. Rep. Jared Huffman (D-San Rafael) announced Thursday that more than $8.6 million has been awarded to the Humboldt Bay Harbor, Recreation, and Conservation District to go toward the development of an offshore wind terminal in Humboldt Bay.

It’s the latest step for the wind terminal as California continues to try to reach their lofty clean energy goals of 100% carbon-free energy by 2045.

“My district in Northern California has some of the best areas available to help meet the administration’s offshore wind energy goals, and I’m glad I could help secure this grant to support the development of one of the first offshore wind projects on the West Coast,” Huffman said in a prepared statement.

Huffman lauded the funding noting that the awarded money will go toward “studies, site design, and permitting activities for a heavy-lift offshore wind terminal at the Redwood Marine Terminal. The grant will also fund the creation of a bay-wide master plan for offshore wind development and project management and grant administration expenses.”

The Redwood Marine Terminal was the lone offshore wind farm development project on the West Coast to receive funding.

The Birth of the California Current Acidification Network

In the mid-2000s, Hog Island Oyster Company in Tomales Bay had grown into a thriving business that included an oyster bar in San Francisco’s historic Ferry Building.

Then, abruptly, Sawyer couldn’t find any more baby oysters to grow. He’d long bought tiny seed oysters from commercial hatcheries along the Pacific Coast, which produced billions of larvae in a typical year. Suddenly, most of these larvae were dying. “The hatcheries were experiencing unusually high mortalities,” says Sawyer. “At the critical moment, when we needed to plant our seed oysters, none were available.”

Winds on the West Coast often blow from land to sea and push ocean surface waters away from the shore. As this happens, colder and nutrient-rich water from the deep rises to replace it. These upwellings make the waters along the West Coast some of the most biologically productive and ecologically diverse in the world. But the water that rises from the deep is also naturally more acidic because as dead marine life sinks into the deep, then decomposes, it produces CO2.

When the already CO2-enriched upwelling deep sea rises to the surface and encounters even more carbon dioxide from the atmosphere, it turns “corrosive,” says former California Sea Grant director Moll.

This hits shellfish hatchlings particularly hard. Oyster larvae build their first protective shells within six hours after emerging from the egg. The shells protect the larvae as they float in the water column, where they’ll remain until they’re large enough to attach to rocks or other substrates.

If calcium carbonate is scarce on the day of hatching because the wind has caused mineral-dissolving deep water to well up, the effort of building the shell can easily overwhelm young oysters. Those that don’t die outright become highly susceptible to disease and predators. If any survive at all, they grow unusually slowly.