A journey along Humboldt Bay to see where the ocean might come in
1/5/12 [excerpts]
In May 2011, Aldaron Laird set out to explore the entire 105-mile perimeter of Humboldt Bay and its three major sloughs. Keeping the tides’ peculiar hours, he launched his little white kayak from dozens of locations, sometimes negotiating slippery slopes and thick brambles. He walked tirelessly, squishing through mud and teetering along rock-tumbled barriers. Frequently he paused, put down his pack, and pulled out digitized maps to ink in adjustments. He shot thousands of photos.
His mission: Record the current conditions of the bay shoreline and sloughs and determine where it is vulnerable to inundation, either from erosion combined with super high “king” tides or from sea level rise driven by long-term climate change. He had been awarded a $33,000 grant from the California Coastal Conservancy for what he had hoped would be mostly a tranquil wander by kayak. That’s not quite how it turned out.
As he travels the bay, Laird has been fine-tuning the details of what he already knows: that 80 to 90 percent of the shoreline is artificial, altered by human endeavor — earthen dikes and railroad beds, roads, rip-rapped low walls and other structures; and that only 10 percent of the native salt marsh remains, some of it growing on artificially altered shore. Laird has been noting where human structures could be inundated. He also wants to know where existing salt marsh has room to migrate inland as sea level rises and where it might drown because something — most likely a human development — is in the way.
“So far, an awful lot of the entire shoreline is really low,” Laird says. “Particularly the railroad beds and a lot of the dikes. And some bridges. The state is saying to prepare for four-and-a-half feet — 55 inches — of sea-level rise by 2100. Very little around Humboldt Bay can withstand that. If we don’t put the planning effort in now, we’re going to have trouble by 2050.”
Before traveling Humboldt Bay’s shoreline, Laird spent part of 2010 studying maps dating back to 1870 and aerial photos shot between 1948 and 2009. Using the 2009 aerial photos, Laird and his partner in the project, Brian Powell, a GIS specialist at McBain and Trush, Inc., in Arcata, made a master map. On it they marked segments showing different shoreline features — natural, artificial, exposed, vegetated, salt marsh, dike, railroad, and so on. On his walkabout, Laird had to verify, or correct, those delineations along every inch of shoreline. Ground-truthing, they call it. After that, Powell would apply the adjustments, add surface elevations, and construct a final map.
In 2008, California’s governor ordered all state agencies planning construction projects in low-lying coastal zones to take into account projected sea-level increases of 16 inches by the year 2050 and 55 inches by 2100. More to the point, the California Coastal Commission won’t permit a project around Humboldt Bay if the developer can’t prove it can handle a three-foot sea level rise now, minimum, and a six-foot-level rise, maximum, by 2100, says Laird.
Arcata’s marsh/wastewater treatment plant would be at risk of inundation, given enough sea-level rise; relocating it would mean also redoing the sewage and stormwater lines. Pastures around the bay might become salt marsh again if their old, earthen dikes, already crumbling in many places, aren’t bolstered. In fact, said Laird, a lot of ranchers, seeing the inevitable, have been selling their land to the Humboldt Bay National Wildlife Refuge or to the government. Restoration efforts to bring back some natural, tidally influenced systems are under way, including a new estuary at the mouth of Jacoby Creek and another at Salmon Creek, whose once-salmon-choked waters were diked and tide-gated by ranchers.
Laird hopes that when people see his data, and his and Powell’s final map, they’ll be inspired to do much more. And quickly. During a king high tide Laird has seen the rookery and the Tuluwat village site on Indian Island floating on open water, with all of the surrounding salt marshes submerged. He’s seen the bay flood right up to the top of the railroad tracks near Arcata and to the lip of a dike on Gannon Slough. “Just a little bit more and it will spill over and into the fields and highway,” he said.
“I think [the idea] is so big, people just don’t want to deal with it,” Laird said, sitting in his Arcata office one day in early December. One of the pelican skeletons he’d found lay thinly on a bookshelf. “Look at Caltrans — they’re spending millions to rebuild the 101 corridor, and yet they’re not putting it on a causeway. Maybe they should be. When I’m out there walking around those places, or kayaking, I try to imagine the scale of the impact. And I think, who’s going to hold the ocean back?”
This new project had desk work, too. But Laird imagined that he’d spend much of his time in the field skimming along happily in his little white Dagger kayak. Besides the serious work at hand — the mapping — he was charmed by the notion he might be the first person to consciously cover every inch of bay and slough shoreline, shooting evocative photographs and scouting out potential new kayak launch sites while he was at it.
Instead his journey, now nearly completed, turned out to be a bit more of a slog — on foot, through mud, weeds and occasional filth. Mostly he had to go out at low tide, because he needed to see the shoreline exposed to be able to tell its nature and condition. He ended up hiking two-thirds of the 105 miles. The rest he mostly kayaked, although he sometimes took the Humboldt Baykeeper boat to inventory the industrial shoreline around Eureka. Occasionally, he had to be innovative. When he needed to get to a far southern portion of bay shoreline, up against a steep bluff encased by private property, he ventured out at low tide in a deep channel cutting through South Bay’s mudflats — it was there he saw that colony of seals — then, as the tide began to rise, bringing with it the shrieking, feeding shorebirds, he paddled toward the bluff and back along the shoreline.
Through it all, Laird has gathered a unique collection of encounters and visions that probably no one else can lay claim to. He has wandered every edge and sometimes the middle of that alien world that shimmers between our dwellings and the great, roaring ocean.
