Natural Perspectives -- Lou Murray and Vic Leipzig

Lou Murray and Vic Leipzig

The bulldozers have been active at the Bolsa Chica this week. Maybe

you saw them and wondered what was going on.

As part of a mitigation project to repair bulkheads in Huntington

Harbour, some homeowners there are footing the bill for a small habitat

enhancement project in the wetlands at Warner Avenue and Pacific Coast

Highway. Workers from Tetra Tech Inc. have been hard at work, scraping

out some new channels to bring seawater back to a few thousand square

feet of former wetlands.

The first step was to replace the old metal culverts that carried

water from the main channel near the Warner Avenue bridge onto the

mudflats in front of the Bolsa Chica Conservancy Interpretive Center. The

old culverts were only a foot wide and had rusted through.

This portion of the Bolsa Chica was restored back in 1978, along with the Inner Bolsa project. In our opinion, the culverts were set at too

high an elevation back then. They allowed water onto the mudflats at only

the highest of tides. Consequently, the mudflats there have languished.

Without the regular twice daily flushing of seawater, that portion of the

wetlands is not functioning as well as it could. Although the project is

more than 20 years old, those mudflats have become populated with a good

growth of marsh plants only in the past few years.

The good news is that the replacement culverts will be 18 inches in

diameter instead of 12 inches, will be made of polyvinyl chloride (PVC)

instead of metal and will be set slightly lower in the ground. The larger

diameter and lowered elevation of the pipes will allow more seawater to

enter the marsh. This should help restore greater diversity and

functionality to the area.

Over the past 24 years, the marsh plants have filled in the wetter

portions of this little salt marsh very nicely. We’ve enjoyed watching

the comeback of three species of pickleweed and a creeping, chartreuse

marsh plant called saltwort. The area in front of the Interpretive Center

is the only place in the Ecological Reserve with any significant amount

of annual pickleweed, so we’re pleased that it will soon get a greater

volume of seawater and more regular flushing. Sea lavenders planted a

number of years ago by the Bolsa Chica Conservancy have self-propagated

and are now scattered over the mudflats. Saltgrass and shoregrass are

abundant in this area and, if you look hard enough, you can find marsh

heather and other wetlands plants scattered about. But there aren’t that

many invertebrates on the mudflats, probably due to the lack of regular

tidal flushing. Consequently, not many shorebirds feed there.

The portion of the salt flat that lies to the west of the parking lot

driveway has been relatively devoid of sea life because it receives

almost no tidal flushing. Horn snails are the primary resident. We were

pleased to see hundreds of polychaete worm burrows for the first time

this year. The increased flow should benefit these animals and contribute

to greater diversity.

One feature of this project is the excavation of two new channels due

west of the Interpretive Center in an area that is currently dry. The

construction project also involves removing an old concrete foundation

next to Pacific Coast Highway and replacing it with wetlands. Before the

demolition, we photographed the structure for the Bolsa Chica Conservancy

files.

We would have preferred to see the present channel deepened and the

culverts lowered even further to bring in more seawater. In our opinion,

and in the opinion of the folks at Tetra Tech, this enhancement project

could have been better. But the Coastal Commission staff didn’t want to

disturb the existing wetland to enhance it, even though this area is

artificial marsh created from uplands.

What we’re getting is more square footage of marsh near the high tide

line instead of more of the lower intertidal zone, which is more

productive biologically. Looking at this in the most positive light, we

believe that we’ll get enhancement of an area that is well suited for the

threatened wandering skipper butterfly. The area currently has a healthy

stand of saltgrass, but to make this particular butterfly happy, the salt

grass needs to be closer to seawater. The enhancement project will do

just that.

We’re extra pleased that our local Fish and Game biologist, Brian

Shelton, went to bat for the project and got it started prior to summer.

By the time our fall shorebird migrants return, the newly restored area

should be bristling with polychaete worms, their favorite food. We hope

that this restoration project results in more useful habitat for the

shorebirds, because it is certainly not good habitat for them now.

But one thing disturbs us. There was no opportunity for public review

and comment on the project. We think that with more local involvement, it

might have been even better.

* VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and

environmentalists. They can be reached at o7 [email protected] .