Natural Perspectives -- Vic Leipzig and Lou Murray

Vic Leipzig and Lou Murray

One of the subjects we bring up repeatedly is native versus nonnative

plant species. We extol the recent removal of nonnative giant reed and

tamarisk at the Shipley Nature Center in Central Park because it will

make room for native plants and the wildlife that depends upon them. We

applaud the ongoing removal of nonnative iceplant on the Bolsa Chica sand

dunes and the planting of native plants on the mesa because it creates

more natural habitat for native wildlife. And we look forward to the

restoration of the Bolsa Chica to full tidal flushing because it will

make the habitat better for more native species.

The issue of native versus nonnative species isn’t as simple as it

appears on the surface. Mustard, fennel and tree tobacco are said to have

been brought to Southern California by the Spaniards nearly 300 years

ago. These plants have certainly established themselves and spread

throughout the ecosystem. After 300 years, shouldn’t they be considered

native to this area? Purists say no.

If a species is brought to an area by the action of humans, either

deliberately as in the case of eastern oysters and eucalyptus trees or

accidentally as in the case of ribbed horse mussels and Russian thistle,

we call it an introduced, nonnative species. Introduced species can have

devastating impacts on people and the ecosystem because the normal checks

and balances built into their native habitat is absent in the new

habitat. Without predatory controls, an introduced species can expand to

the detriment of what was already there. This forces us to take action.

We as a society frequently are required to spend enormous amounts of

money to eradicate an introduced pest. The killer algae introduced into

Huntington Harbour is one good example. In its normal environment, snails

keep it under control, but those snails are not found here. If this

native of the Caribbean had become established here, it would have

smothered most of the plant and invertebrate life in the bay as it has in

the Mediterranean Sea. We believe the decision to eradicate it was a good

one.

Demonstrating “survival of the fittest,” some species expand their

range naturally. Cattle egrets spread on their own from Africa to South

America to the southern United States. They are now common in the Salton

Sea area and can occasionally be seen locally. They cause no harm and

there is no intention of eradicating them. If a species breeds

successfully in an area for 10 years, it is considered established. Some

say it is then native to the area.

But the bottom line isn’t really whether or not a species has been

here since time immemorial. After all, the earth is not stable. Climate

changes. Shorelines shift. Mountains lift.

Species are not stable either. They evolve. Over geologic time, new

ones appear as old ones disappear. Plants and animals spread and decline

based upon their ability to survive the inevitable natural changes that

occur on earth. We recognize these natural changes and do not advocate

preserving things just as they are at this point in time. But we do

believe in attempting to slow the loss of species diversity brought about

by the actions of humans.

Preservation of species diversity is our goal, not preservation of the

status quo in a particular geographic area. To this end, we tend to

support the eradication of introduced, nonnative species because they

have a negative impact on native species, many of which are threatened or

endangered by the actions of humans. As the earth holds more and more

humans, diversity in the wild declines as more and more natural habitat

is lost.

This is why we have fought so hard to preserve the Bolsa Chica and

restore full tidal flushing. Only full tidal flushing will allow the

maximum diversity of native species to thrive.

In anticipation of the changes that will occur over the next few years

at the Bolsa Chica with restoration, we recently conducted a casual study

of the marine invertebrates seen at low tide in the rocky intertidal

zone. We compared species found in the muted tidal system by the tide

gates between Inner and Outer Bolsa Bay with those found in the fully

tidal system under the bridge over Anaheim Bay on Pacific Coast Highway.

In the muted system, we found mussels, barnacles, predatory snails called

Kellet’s whelks, nudibranchs called ring-spotted dorids, California sea

hares and both lined and yellow shore crabs. In the fully tidal system,

we found most of the same species. In addition, we found two species of

starfish, giant keyhole limpets, striped sea hares, fat innkeeper worms,

sea cucumbers, gem murex and Poulson’s rock snails. The difference in the

number of species in the fully tidal system compared to the muted tidal

system was remarkable. Although both areas were rocky intertidal zones in

a connected body of water, and both teemed with invertebrates, there was

more diversity in the fully tidal system.

The best way to protect species diversity is to preserve and restore

natural habitat. To all the people in town, so many of you, who have

worked so hard over so many years to help save and restore our local wild

areas such as Central Park, the Shipley Nature Center, Talbert Marsh, the

Huntington Wetlands, the Bolsa Chica wetlands and adjoining mesas, we

thank you.

* VIC LEIPZIG and LOU MURRAY PhD are Huntington Beach residents and

environmentalists. They can be reached at o7 vicleipzig@aol.comf7 .