Epic Ludwigia Paddling

Laguna de Santa Rosa, the second largest wetland of Northern California and habitat of Syncaris pacifica (Photo credit: Wikipedia)

My family and I took to the Laguna de Santa Rosa by kayak recently–we hadn’t managed to get out earlier in the spring and knew we had little time before the water level dropped too much. We put in at the Occidental Road bridge amidst a thinnish patch of Ludwigia hexapetala, the invasive water weed running rampant in the Laguna de Santa Rosa/Russian River watershed. We had last paddled this stretch of the Laguna three years ago and encountered a mostly clear channel except for a relatively small area just south of the Santa Rosa Creek confluence. While the waters under the bridge were clear, we couldn’t go south — not only did Ludwigia fill the channel, but an impassable clump of water pennywort (Hydrocotylespp.) blocked the way as well. Clearly the weeds had flourished since the last control efforts a few years ago. They were a daunting omen for what we would encounter ahead. Nonetheless, we began paddling downstream toward Guerneville Road.

Ludwigia hexapetala (Wikimedia Commons)

We found a narrow channel of clear water — sometimes barely so — and a multitude of birds to distract us from the sometimes difficult paddling as we negotiated the thicker patches of Ludwigia. Great and snowy egrets in breeding plumage dotted the marshy edges; black-crowned night herons flew from the trees on the banks as we approached; marsh wrens trilled from the willow and wild rose thickets; and occasional mallards quacked in the distance.

Although the entire Laguna and its watershed have been drastically altered over the past 150 years ago, this stretch of the Laguna has been more obviously changed. Until the early 20th century, a number of large bodies dotted the Laguna between Cunningham (a few miles south of Sebastopol) and on the Russian River, including Lake Jonive, a favorite boating and swimming area of early Sebastopol (pictured on this blog’s banner). By the 1920s, the Laguna lakes were largely gone, largely a victim of siltation from agricultural erosion. By the 1950s, long-standing efforts by farmers to drain and control the Laguna were underway with a new channel constructed by the Laguna de Santa Rosa Flood Control District following property lines between Occidental Road and Santa Rosa Creek (just south of Guerneville Road). Plans by the Sonoma County Water Agency to extend the channel to Sebastopol never came to pass because the County and the City of Sebastopol began to recognize the Laguna’s value, but many acres of brush and trees had been cleared all along the waterway — a continuation of the massive deforestation that took place during the 19th century as oaks were cut for charcoal and land converted to agriculture.

Once the political climate had shifted, the California Dept. of Fish and Game (DFG) took control of the former flood control district lands and a portion of the lands have returned to marshes and ponds. In addition, a large shallow lake formed just south of the SCWA’ s Delta Pond wastewater treatment reservoir after floodwaters breached the low dikes around a drained field. The current ponds and lake hold much less water than those 150 years ago, but are filled with wildlife.

It was with great relief that we left most of the ludwigia behind as we paddled into the shallow lake.  In addition to all the waterbirds we’d seen earlier, now we saw (and heard) grebes, coots, cormorants, osprey and geese. Then we spotted the grand prize — a bald eagle perched on a dead oak at the far corner of the lake. We slowly headed for the tree, trying not to splash too much. The eagle took off when we were about halfway there, then circled back, landing on the same branch. We kept going and got within 50 yards before it flew away again, this time heading north and out of sight.

We found one more treasure before we paddled back toward the channel and home — I spotted a small mass of vegetation and mud floating in the midst of a thin patch ludwigia. When I looked more closely, I noticed a slightly speckled, grayish egg cradled in the middle. We later found a second nest and when we asked a birder friend, she told us we’d found a pie-billed grebe nest.

The way home wasn’t much easier than our journey out, despite the faint path we’d left through the ludwigia. My wife took our son’s kayak and he sat in the front of the two-person kayak. He waded/swam through a couple of the thickets (both the air and water were warm that afternoon and the water considerably clearer north of Occidental Road) and perched on the front while paddled, his arms dangling in the water. Our epic finally came to an end as we passed under the bridge with hundreds of cliff swallows wheeling overhead and darting into their nests.

Wild Things

Recent sightings…

On a recent evening walk in Sebastopol’s Laguna de Santa Rosa Preserve, my
family and I thought we were seeing grasshoppers in the wild roses lining one of the paths adjacent to a pond, but on closer inspection, the roses were thick with tiny brown and green Pacific chorus frogs (Pseudacris regilla). No bigger than the tips of my fingers, they clung to the leaves and twigs, as well as occasionally dropping from the oak branches above the roses.

 

Anise swallowtail larva

My son called for us to come out to our yard to see something cool. On the fennel plant that he convinced us to let grow next to our strawberry bed, he pointed out several large and colorful caterpillars, which we later positively identified as anise swallowtail (Papilio zelicaon) larvae. We’d certainly seen the adults many times, but had never spotted the larvae before. By the light green color and the use of fennel as a host plant, our caterpillars were evidently near the end of their larval stage (they are darker and prefer poison hemlock in earlier stages). We’ll keep watch for their cocoons.