Sparsely, Sage and Timely
Nationalistic zoology
Back in 1969, my former wife Cathy and I were flying from Luxembourg to Reykjavik, Iceland, when our pilot flew a ways off course. In November 1963, a volcano on the floor of the North Atlantic had begun erupting. By June 1967 when the eruptions stopped, the volcano had risen above the surface of the ocean to form the new island of Surtsey. Because a column of volcanic smoke was still rising thousands of feet, our pilot took a detour so we could see it.
Cut off from the main island of Iceland by more than 20.5 miles of open ocean, Surtsey provided scientists with an ideal spot to study the spread of plants and animals. Every species that appeared on the island was "non-native." Scientists went so far as to wear surgical garb when they visited Surtsey so they would not inadvertently "contaminate" it with new species.
Yet by now, Icelandic biologist Sturla Fridriksson happily reported last year, 60 species of plants are growing on Surtsey, 12 species of birds, and several species of insects, including moths and beetles.
Imagine what would have happened if biologist Fridriksson had been doing his research in West Marin instead of on Surtsey. The Environmental Action Committee, the Park Service, and a host of freelance researchers would be sounding alarms about all these invasive species. To such groups, the steady spread of plants and animals around the globe is horrific.
I would agree that some non-native critters do present a clear-and-present danger in new locations. Zebra mussels from the Caspian Sea began showing up in the Great Lakes in the mid-1980s, arriving in the ballast ships. Zebra mussels are so prolific that bunches can smother native clams and the spawning grounds of fish. What upset people most, however, was that clusters of zebra mussels began clogging municipal waterpipes going into the lakes.
These days, green crabs from Europe are menacing Tomales Bay, having reached the San Francisco Bay Area from Europe – again in the ballast of ships. As it happens, green crabs are voracious predators that feed on other crabs, as well as shellfish. Not only are they strong enough to crush a mussel’s shell, the females lay up to 185,000 eggs at a time and live three years.
If I were going to allocate tax money to control a non-native species in West Marin, green crabs would probably get the bulk of it. It’s not that the crabs are being ignored by researchers; however, they – not 1,200 Asian deer in the 71,000-acre Point Reyes National Seashore – should prompt a red-alert at the Park Service, which has jurisdiction over much of Tomales Bay.
Instead, the non-native species getting the most attention here from certain nationalistic naturalists are white deer, ice plant, dune grass, and "pampas grass." More about pampas grass in a moment.
The Global Invasive Species Database compiled by the Invasive Species Specialist Group of the World Conservation Union has identified "100 of the World’s Worst Invasive Alien Species." These include rabbits, field mice, rainbow trout, housecats, yellow-jackets, red foxes, short-tailed weasels, Argentine ants, bullfrogs, wild blackberries, and mosquito fish.
Now I’m no fan of those little ants that show up whenever the weather changes nor of yellow-jackets, but I can live with them. Housecats certainly can be a problem when not kept in the house; bullfrogs eat the tadpoles of other frogs; and red foxes sometimes prey on rails and other shorebirds. But although these critters have taken up residency in the parks of West Marin, the Park Service isn’t about to start shooting any of them.
There are many species that can alter an ecosystem when they show up, but in time ecosystems adjust to them. Rabbits, which originated in Europe and North Africa, are now found worldwide except in Asia (which has hares) and Antarctica. Numerous predators in West Marin now count on rabbits as a staple of their diet although in Australia, some ecosystems are still adjusting to their arrival.
The list of 100 worst invasive species does not include eucalyptus trees, which originated in Australia but are now found in locales as distant as the People’s Republics of China and Berkeley.
Nor does the list include ice plant; it originated in South Africa and is widely used here as a ground cover where erosion is a problem. The reason it’s all over the Park Service land is that it was planted to stabilize such public works as roadcuts, pathways, and several parking lots at the edge of beaches.
Sure, ice plant changes ecosystems, but so do the Point Reyes National Seashore’s roadcuts, pathways, and parking lots. Moreover, once the National Seashore manages to rip up all its ice plant, the amount of public works needed to stabilize its roadcuts, pathways, and parking lots will likely be expensive and far more disruptive to the environment than the ground cover ever was.
I might be more sympathetic when West Marin naturalists and the Park Service talk about the need to eliminate pampas grass if they were informed more by science than zeal. You would think that when the Park Service and other institutions recruit volunteers to help eliminate an invasive species, they would at least know what species they’re talking about.
The problem plant, which is particularly noticeable along the Point Reyes-Petaluma Road near the spillway of Nicasio Reservoir and along Highway 1 west of Stinson Beach, is not pampas grass (Cortaderia selloana) but Andean grass (Cortaderia jubata).
You can easily tell them apart. The white plumes of true pampas grass extend only slightly above the clump while the often-pinkish plumes of Andean grass stick far out of the clump. It’s the Andean grass whose seeds blow in the wind and germinate wherever soil is bare.
Pampas grass can also be a pest, but seldom in Northern California. Clumps may grow outward, but they’re less likely than Andean grass to spread seeds that start clumps elsewhere. Why? Cortaderia selloana cultivators favor female plants because their plumes are more luxuriant. Here’s what the California Invasive Plant Council has to say about Cortaderia selloana:
"Flowers of some plants consist of both male and female parts on the same flower, but only the male parts are functional. Other plants bear only female flowers… Over the years, selection for ornamental plants in California has been for the showier plumes of the female plants. Consequently, few opportunities exist for seed production. This may account for the lack of spread of this species in California in past years."
I’m not suggesting that the Park Service, the EAC, or anybody else should ignore all non-native species, but these groups need to show a bit more common sense.
Dune grass and ice plant were planted for purposes that remain valid. Nor are there enough Asian deer in the National Seashore to warrant an extermination program; indeed, Park Service pilot projects elsewhere have found contraception is effective and cheaper.
On the other hand, bringing 1.9 million humans a year to Point Reyes has an enormous impact on the environment, but the Park Service isn’t likely to start hunting visitors any more than it is likely to hunting non-native short-tailed weasels, rabbits, or red foxes.
Where the Park Service needs to put its money (assuming green crabs won’t get it) is on reducing the amount of certain native species in the park. By allowing grasslands to brush over with coastal chaparral, the Point Reyes National Seashore has been destroying ecosystems that scientists believe had existed for more than 10,000 years.
Not only do brushed-over meadows become impenetrable to humans, they no longer provide habitat for various rodents such as ground squirrels that, in turn, are prey for hawks, owls, and other raptors. It is boggling that the Park Service finds the elimination of un-American deer