Effort renews to control invasive Asian kelp

A long, wavy greenish-brown kelp dangles off the docks at South Beach Marina by AT&T Park in San Francisco.

It may seem like the seaweed belongs there, but it’s an invasive kelp from Asia, known as Undaria pinnatifida. It’s so ubiquitous that efforts to remove it at South Beach Marina have been virtually abandoned.

“[The] ideal situation is to start on the edge of a population and work on, but we never had the resources at South Beach Marina,” said Chela Zabin, a marine biologist with the Smithsonian Environmental Research Center.

Recently, however, there’s been a renewed effort to address this invasive, edible seaweed, also known as wakame. Since its discovery in 2009, undaria control has mainly been a volunteer effort. Zabin and others have tackled the problem in well known spots, such as the San Francisco Marina and Pillar Point at Half Moon Bay. Now she’s managed to bring others to the cause, namely an invasive species management coalition, the Bay Area Early Detection Network.

With the expected arrival of a federal fisheries grant for just under $20,000, BAEDN plans to provide technical support and funding to spot and remove undaria at Pillar Point on Half Moon Bay. Part of the money will go to coordinate boaters, divers and anyone who is interested in volunteering time and effort to control the spread of Undaria in San Mateo County.

Zabin thinks if they get it right with Undaria, the effort might have larger implications.

“If we organize this network of people to look for Undaria, we will already have the structure in place to look for other nonnatives,” Zabin said.

Undaria is an especially good traveler, and can be hard to spot. It attaches to floating docks, boats or anything in the water. And it reproduces by spores, so it can spread through the water very easily. It has been found in smaller marinas where it attaches to yachts and sailboats.

Once it gets out there, undaria outcompetes the native kelp that some fish need for shelter, food and egg-laying. The potential impacts of a ballooning undaria population threaten the underwater ecosystem of the Bay and the

larger estuary. That makes it bad for businesses, too. Aquaculture has taken a hit from undaria infestations in Argentina and the Netherlands. Zabin said she’s warning oyster farmers in Tomales Bay about the dangers of an undaria invasion.

“If it were to get to Tomales Bay, that could be pretty serious,” she said.

The idea of removing a marine invasive species is relatively new and it is perhaps trickier to see the connections in a marine environment, Zabin said. This sort of “out of sight, out of mind” bias is beginning to change.

She cites an invasive seaweed caulerpa, nicknamed the “killer seaweed,” that was found in San Diego in 2000. With the help of herbicides and $6 million, the California Department of Fish and Game declared the invasive eradicated six years later. Undaria could be just as difficult to uproot.

“But I think it’s still possible,” Zabin said.

diver with undaria — Diver Carliane Johnson pulls up undaria. Photo by Chela Zabin.

At the 2011 State of the Estuary conference, Zabin approached the BAEDN about working together on the undaria removal project. BAEDN applies a systematic approach to tackling invasive species, beginning with cataloguing where the invasive is present and prioritizing what areas should be worked on first. Zabin hopes to bring techniques like this, normally used to manage landlubbing invasives, to the underwater world.

Controlling undaria will come down to regularly surveying locations, and then pulling it out. One of BAED’s high priority spots is Half Moon Bay, where the population quickly expanded before its discovery. Meanwhile, divers at San Francisco’s Aquarium of the Bay monitor an Undaria population bordering the building at the Hyde Street pier. Zabin hopes that other entities with sizeable waterfront property will also “adopt their backyard.”

Although it is edible (goma wakame is seaweed salad at sushi restaurants), Zabin does not eat the undaria she pulls. Because she pulls them every month, the plants are usually small, and they are taken from contaminated areas in the marinas. Instead, Zabin’s discarded wakame typically ends up as garden compost, where it’s finally bested on land.

A website is available for those who would like to help control the spread of undaria, with plenty of information for aquaculturalists and boaters as well.

Alcatraz Island is a renowned prison — but a horticultural gem?

From afar, this windswept island in the middle of the San Francisco Bay appears so rugged that you’d expect to find only century plants and eucalyptus. But Alcatraz is alive with color. Hidden amongst the leeward hillsides, flowers such as Mexican blanket, Shirley poppies and roses grow. Woody succulents and nasturtiums branch over the hillside on the windy western face, across from bright patches of sheltered bulbs and a patch of Matilda poppies.

Many of the plants are imported exotics, the result of decades of careful cultivation by staff and prisoners who created patches of beauty in the otherwise forlorn setting of concrete and steel. More than 200 species or varieties of plants have been introduced to the island since the late 1800s.

“Because Alcatraz is a cultural landscape, it is not as important to plant natives,” said Shelagh Fritz, the Garden Conservancy’s project manager for the Alcatraz Historic Gardens on a press tour of the gardens.

Historically, military officers, wardens and prisoners alike tended the well-manicured gardens on Alcatraz while living on the island. Although the once-barren island originally had a thin layer of topsoil and no source of freshwater, inhabitants of the island sought to make it more lively by planting exotic flowers, trees and shrubs.

The gardens were neglected for 40 years following the prison’s closure. By 2004, the Garden Conservancy, Golden Gate National Parks Conservancy, and the National Park Service partnered in an effort to revive the horticultural landscape of the island.

Every Wednesday and Friday mornings, the first boat to Alcatraz ferries volunteers wearing maroon shirts stating their mission: Alcatraz Garden Restoration. Cumulatively, they’ve put in 40,000 hours of work and revived 4.5 acres of gardens.

Apparently there was a lot to do; it took two years to clear out the overgrowth to reveal fuchsia, pelargonium, aeonium and rose bushes. The outline of garden paths and planting beds appeared and guided the volunteers. Old photographs brought by former Alcatraz residents and their families also provided visual references to restore the gardens.

Tucked into terraces

It’s easy miss the garden attractions if you head straight to the prison, as, no doubt, many tourists aim to do. Along the main pathway crisscrossing the island are the foundations of old homes, called Officer’s Row, where army officers lived during the military occupation of the island in the mid 19th Century before it was converted to a prison in 1861.

The army officers and their families established the Victorian-style gardens with topsoil that had been imported to the island to install cannons on the hillsides.

When management of Alcatraz switched the Bureau of Prisons in 1934, several of these homes were demolished, but the gardens survived. Staff families and inmates enlarged the terraced gardens around the homes to cultivate the land within the foundations. Only those prisoners who had rapport with the prison staff would be given the privilege of tending these gardens outside the prison walls.

Signs of their work remain. While clearing overgrowth from the Rose Terrace, Fritz found a handball, a small rubber ball inmates used during recreation.

“It felt pretty cool to hold something that was last touched by an inmate,” Fritz said.

Volunteers have intentionally left some of these gardens to nature, and nature is coming back. Where a burned down warden’s house once stood, black-crowned night herons now nest in the overgrown vegetation.

“It’s kind of interesting how plants just take over all the ruined buildings,” Fritz said.

The west side gardens withstand the harshest weather and are populated by climate-hardy, plants that grow in a Mediterranean climate like aloe and drosanthemums. Fig trees and snowy egret nests have taken over a former lawn used for inmate recreation.

One inmate, Eliot Michener, was considered a to be so non-threatening that he was allowed to care for gardens on the west side. He did so for nine years, 1941-1950, as if they were his own, creating a terraced design with ornamental plants.

A shining symbol of his work is the cottage-style garden near a small tool shed of his making. Annuals mixed with perrenials planted in a free-flowing, patchy landscaping design shout color and exuberate beauty. Fritz designed the restored garden, using flowers that closely represent what Michener had chosen more than 60 years prior. Stories such as this are important to Fritz and other volunteers. They create a connection across generations through the plants that survive in the severe conditions of the island.

“We want to restore the gardens, but we also want to tell those stories,” Fritz said.

Propagating plants

A reconstructed greenhouse stands not far from where Fritz picked up that handball. Fritz instructs volunteers how to propagate plants and set up experiments in hybridization.

“It’s fun to collect seeds and see what happens,” Fritz said.

The soil for the greenhouse plants is created less than 30 yards away through a composting system developed by Dick Miner, a Garden Conservancy volunteer. Miner spearheads the project in an effort to make the island more sustainable.

“We make our own dirt,” Miner said.

Miner uses ingredients from the island, including garden trimmings and waste; wood chips from ivy blackberries and roses; and coffee grounds from the gift shop. Horse manure from a farm down the road from Miner’s house adds extra nitrogen.

The result is a rich, compost soil that’s won awards in recent years in the Marin County Fair, most recently first place in 2012. What compost isn’t used to pot plants is applied back to the gardens.

Besides re-creating soil, Alcatraz’s new gardeners have found a way to solve another limitation of the island — the lack of freshwater. A barge brings water daily, but in 2009 volunteers saw potential in abandoned structures on the island, specifically large cisterns that used to recycle water from the prison showers to irrigate the recreation lawn on the west side.

With the help of landscape designers, the volunteers devised a catchment system to store rainwater and fog drip in the cisterns, which can hold up to 12,000 gallons. Water from the cisterns now feeds the western gardens.

“The best part is seeing the whole process take place, from clearing to planting and watching it all grow,” Fritz said.

She leads a guided tour through the gardens, some of which are normally closed to the public, twice a week Friday and Sunday mornings at 9:30 a.m., year-round. On Wednesdays from 11 a.m. to 2 p.m. one can listen in on garden talks in Officers’ Row.

Visit alcatrazgardens.org for more information.

Bay Area has ticks, and Lyme disease

Back East, it seems everyone has a story to tell about ticks. My brother, for example, narrates with horror a time he trudged across some overgrown farm fields in Michigan early one evening, only to look down and see dozens of dark specs on his legs; he was covered in the eight-legged bloodsuckers.

Locals to the Bay Area sometimes forget about the hazards of these little predators when exploring nature. But maybe they shouldn’t. Ticks carry Lyme disease, a debilitating condition caused by a bacterial infection ticks pick up from biting deer and mice.

“Some physicians tell their patients that Lyme disease doesn’t exist in California or is very rare,” Dr. Bob Lane said, a UC Berkeley entomologist. “Lyme disease is locally an issue in some Bay area counties, such as in Sonoma and Marin.”

Fewer tick species live on the West Coast, but there are enough of them to carry six different diseases. Lyme disease accounts for over 80 percent of tick-borne diseases in California, according to Lane. He has studied Lyme and other tick-borne diseases in California for over 35 years.

In California, the disease occurs most commonly in the Northwest coastal counties and right here in the Bay Area, which averages five to six cases each year, according to the Centers for Disease Control and Prevention (statewide the rate of contraction is quite low: 0.3 per 100,000 persons each year).

The symptoms of Lyme disease are difficult to diagnose. They range from an expanding circular rash to flu-like illness to cognitive problems. If not caught early, the disease can be difficult to beat.

Preventing Lyme disease

As spring draws to a close, ticks will be in their peak phase of abundance as young juveniles, ending mid-summer. Juveniles at this stage are also most likely to contract Lyme disease, Lane said. With the warmer weather and start of hiking season, it’s also the time of year when people are most likely to come in contact with ticks infected with Lyme disease

The best ways to limit exposure is to wear protective clothing, use repellents, and do regular tick checks on hair and clothing. Nymphal ticks, in the second juvenile stage, are about the size of a poppy seed.

“If you don’t mind looking like a nerd, tuck pants into socks,” Lane said, although he admits to “living dangerously” and not always practicing his own advice.

Curiously, Lane said the overwhelming majority of young ticks in north-western California attach to lizards, and especially the western fence lizard. Fortunately for us, this widespread lizard contains, within its immune system, the power to kill the bacteria of Lyme disease. When a tick bites a western fence lizard and has Lyme disease, the bacteria will die and neither the tick nor lizard will carry the disease.

Lane and others who’ve studied this specialization think this is the primary reason why the infectious rate of Lyme disease is so low in California, and why so few adult ticks carry the infection.

“The lizard appears to be cleansing affected nymphal ticks, and in some sense doing humankind a service,” Lane said.

Where to beware

Contrary to popular belief, ticks do not fall from trees, and it’s not hiking that’s the problem per se. Rather, entering tick habitats is what puts you at risk for becoming tick bait. Contact with wood is the most dangerous spot to be in.

Lane has seen the greatest amount of young ticks in oak and Douglas fir woodlands, living in leaf litter and crawling on logs. A behavioral study conducted by Lane proved that sitting on logs is the riskiest behavior when it comes to ticks during this time of year.

A transitional area from one type of habitat to another, such as the conjunction of woodland and grasslands, also holds high populations of young ticks, Lane said.

Beware especially when clearing brush along a forests edge, such as during trail maintenance projects. Hilly areas, such as the coast ranges, can host a higher abundance of ticks.

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For more information on ticks and Lyme disease:

* A lab in Palo Alto where you can send a tick to be tested for Lyme disease.

* California Lyme Disease Association.

* Tick management handbook.