Kathleen M. Wong
About the author

Bay Area native Kathleen M. Wong is a science writer specializing in the natural history and environment of California and the West. With Ariel Rubissow Okamoto, she coauthored Natural History of San Francisco Bay (UC Press, 2011), for which she shared the 2013 Harold Gilliam Award for Excellence in Environmental Reporting. She reports on native species, climate change, and environmental conditions for Estuary, and is the science writer of the University of California Natural Reserve System.

Articles by Kathleen M. Wong

Big Boulders, Big Benefits to Coyote Creek Fish

As a source of flowing water, upper Coyote Creek is unreliable at best. Though storms swell its banks in winter, Mediterranean-climate summers shrink this South Bay stream to a series of isolated pools by August. “By October right before the rains come, we’re down to these really small pools that have all the fish in them,” says retired U.S. Environmental Protection Agency ecologist Rob Leidy. Leidy and UC Berkeley fish ecologist Stephanie Carlson began monitoring the annual dry-down of upper...
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New Way to Sleuth Out Fish IDs in the Field

The CRISPR technique used to edit DNA has been formulated into a tool that can distinguish between similar-looking California fish species for conservation research. Called SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing), the tool can tell the difference between species with speed and accuracy. Better yet, it is both inexpensive and can be run while researchers are in the field. “It puts the power in the hands of the field biologist to make the most informed decision versus waiting sometimes days...
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photograph of beautiful tree overhangin a river

Modern water management practices damp down natural river patterns and produce streamside forests that “live fast and die young.”

Such practices also hasten the destruction of an important and dwindling habitat. Melissa Rohde of the State University of New York College of Environmental Science and Forestry (SUNY-ESF) and colleagues analyzed five years of high-resolution satellite and water resource data showing vegetation greenness along California rivers. Trees growing alongside the 30 percent of state rivers with natural flows decreased in greenness from the wet spring through the dry summer months, the scientists report in the Proceedings of the National Academy...
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The increasing flow of microplastics entering San Francisco Bay from trash, fleece clothing, car tires, and myriad other sources is likely being trapped by a surprising filter: native eelgrass (Zostera marina).

Miniscule polymer pieces the size of a sesame seed or tinier, microplastics pose a growing pollution threat to marine environments worldwide. To understand how microplastics accumulate in nearshore, urbanized environments, researchers quantified the prevalence of microplastics in and around the Zostera marina meadows of Deerness Sound, in the Orkney Islands of Scotland. Mark Hartl and colleagues at Heriot-Watt University found that microplastic flakes, fibers, and fragments were twice as concentrated in the water above eelgrass meadows as in adjacent control...
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A resurgence of dinoflagellates, which can cause harmful algal blooms, may be in the cards for some bays along the U.S. West Coast.

A resurgence of dinoflagellates, which can cause harmful algal blooms, may be in the cards for some bays along the U.S. West Coast. Scientists at UC Santa Cruz have been monitoring phytoplankton weekly at the town’s Municipal Wharf since 2002. In 2018, Alexis Fischer, then a postdoctoral fellow at UC Santa Cruz, augmented these observations with an Imaging FlowCytobot (IFCB) that photographed wharf phytoplankton hourly. She also developed a machine learning classification algorithm to automate identification of the organisms. In...
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Network Listens for Passing Salmon

It’s a cold morning in early February, and Chris Vallee of the U.S. Geological Survey is motoring upriver along Steamboat Slough. His two-man crew is hunched in the bow with backs to the wind, wrapped to the ears in water-resistant jackets above warm layers. Vallee pilots the vessel in relative comfort behind the shelter of the windscreen. The boat passes the usual Delta sights: greenish-brown water drifting past road-crowned levees, the occasional dock and house, a greater egret the color...
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Manmade features in the Delta, including riprap-armored banks, water diversion pipes, pilings, and woody debris, may be sending juvenile native fishes into the jaws of finned invaders.

“We know from a decade of doing survival studies that migrating juvenile salmon are dropping out of the system pretty much everywhere in the Delta,” says UC Santa Cruz fisheries biologist Brendan Lehman. “Physical habitat features are potentially aggregating predators and prey in ways detrimental to salmon smolts and steelhead.” The scientists report in the December 2019 San Francisco Estuary and Watershed Science that artificial light and submerged aquatic vegetation pose the most severe and widespread risks to native fishes....
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A gene tells Chinook salmon whether to return to their native streams to spawn in spring, fall, or sometime in-between, according to new research.

The finding, by UC Davis graduate student Tasha Thompson and colleagues, helps distinguish between spring- and fall-run fish—and could help save spring-run salmon from human-hastened extinction. Fall-run populations enter rivers in autumn and spawn immediately. By contrast, spring-run fish return during peak snowmelt, linger in tributaries through summer, and spawn around the same time as their fall-run brethren. “Spring-run fish are special for a lot of reasons,” Thompson says. Spring-run salmon historically spawned in the upper portion of watersheds, nourishing...
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A marriage of robotics and artificial intelligence promises to automate the detection of harmful algal blooms, which can trigger shellfish harvesting bans and fill wildlife rescue centers with sickened animals.

The Imaging FlowCytobot (IFCB) takes water samples around the clock and photographs phytoplankton cells floating within. “It’s got a huge amount of potential for figuring out what plankton is in the water column and monitoring for HABs,” says Alexis Fischer, a postdoctoral fellow at the University of California, Santa Cruz with Raphael Kudela. Fischer and colleagues are building a phytoplankton image classifier already capable of identifying more than 90 percent of cells photographed by IFCB at the Santa Cruz Wharf. The...
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Sleuthing Sturgeon Snags

Local green sturgeon are struggling. The population that spawns in the Sacramento –San Joaquin River Delta was declared federally threatened in 2006. Researchers at UC Davis, which hosts the world’s only green sturgeon rearing program, are now trying to figure out why the fish is in trouble. “If we knew how large they are when they’re moving through each portion of the system, we’d know a lot more about the threats they face at each life state, and where we...
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Restoring wetlands is an extremely effective way to cool land surfaces, a study conducted in the Sacramento-San Joaquin Delta indicates.

For three years, Kyle Hemes of UC Berkeley and colleagues kept tabs on the heat flux and air flow above three restored Delta wetlands on Twitchell and Sherman islands, and an alfalfa field on Twitchell Island. Surface temperatures at wetlands with open water were up to 5.1 degrees Celsius cooler than the crop field during the daytime. As expected, the dark open water absorbed more solar radiation, and released the energy slowly at night. But wetland vegetation played a role...
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Recent discoveries are promising new weapons against red tides, the massive blooms of microscopic marine algae that are notorious for playing havoc with marine ecosystems.

The culprit behind poisoned seabirds, closed crab fisheries, stranded sea lions, and shellfish poisoning in humans are often diatoms producing the neurotoxin domoic acid. Now, scientists have identified the genes and biochemical processes responsible in diatoms of the genus Pseudo-nitzschia. The finding, published in the journal Science, opens the door to rapid genetic monitoring of algal blooms as a means to spot nascent harmful blooms and track their spread. “By identifying the genes that encode domoic acid production, we are...
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California sea lion nurseries are moving north as Año Nuevo Island and the southeast Farallon Islands experience a record-breaking boom in sea lion births.

Zalophus californianus have traditionally preferred nurseries in the Channel Islands, but the population of pups born off Northern California’s coast began skyrocketing in 2016. Births at both sites went from a few dozen pups to more than 500. The trend has only intensified since; more than a thousand pups born at the Farallones, and between 500 and 700 at Año Nuevo, in 2017 according to NOAA; similar numbers are expected this year, although final counts are not yet available. Such...
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SF State Launches New Floating Sentinel

Two banana-yellow buoys anchored along the Tiburon shore will be San Francisco Bay’s sentinels against shifts in water chemistry due to climate change. Known as the Bay Ocean Buoy (BOB) and the Marine Acidification Research Inquiry (MARI), the permanent moorings will provide long-term monitoring of acidity and carbon dioxide levels—key indicators of how the changing ocean will impact Bay chemistry. “It’s taken over three years of perseverance and partnership building to get these instruments into the water, but now we’ll...
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Cold Curtain

Cold water, essential for the life cycle of Chinook salmon, is all too often in short supply along the Sacramento River. A primary cause: California’s massive water conveyance system, using reservoirs, dams, and hydroelectric plants to divert water and deliver power to farms and cities. “When we started releasing water in spring, we let cold water out too early. None was left by fall, when salmon really needed it,” says USBR hydraulic engineer Tracy Vermeyen. Two clever innovations have been...
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In hot water due to climate change, many ocean fish are moving to higher latitudes or deeper waters to find the conditions they need to survive.

These include lobster, black bass, and Atlantic cod, all of which have supported iconic fisheries along the Eastern seaboard of the United States. “Ocean animals are moving ten times faster than animals fleeing climate change on land,” says Rutgers University marine biologist Malin Pinsky, whose Rutgers OceanAdapt website enables visitors to explore changes in marine species distributions over recent decades. These range shifts are causing headaches for fishing fleets, which are forced to head farther out to sea or hundreds of miles further from...
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Man’s best friend is being enlisted in efforts to detect the soil-born pathogen responsible for sudden oak death and other rapidly spreading plant and tree diseases.

Phytophthora is difficult to detect in nurseries, plant materials, and planting sites until it has done its damage. To develop early-detection options, H.T. Harvey and Associates are training a female cattle dog/border collie mix named Bolt to sniff out Phytophthora. Part of the Harvey Dog ecological-scent detection program, Bolt has accurately identified four species of Phytophthora in the lab. If her training in a natural setting is successful, Bolt could get to work helping minimize the spread of Phytophthora. Potential beneficiaries...
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Options for Orphan Species

Off a bustling Delta highway, next door to a branch of the California Aqueduct, sprawls a tidy collection of shipping containers, humming pumps, and cylindrical tanks. Paved in cracked asphalt and encircled by chain link fencing, it resembles any number of light industrial sites at the margins of many communities. In fact, this resolutely artificial site is devoted to preserving a disappearing piece of natural California: the Delta smelt. “Our fish are a refuge population,” says Tien-Chieh Hung. Director of...
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