Fish and Wildlife Check-up
of the Estuary Conference presentations featuring decades of data on fish,
ducks, seabirds, and cetaceans revealed both hopeful and alarming trends.
loss of federal funding for the midwinter waterfowl survey, usually conducted
using small aircraft, has researchers looking at drone-based alternatives,”
said waterfowl biologist Susan De La Cruz of the US Geological Survey.
overall community condition of the Estuary’s fish (abundance, distribution,
diversity, proportion of native to non-native species) has declined, reported
the National Resources Defense Council’s Christina Swanson, citing the 2019
State of the Estuary Update, Bay Study and other surveys.
breeding success of California least terns and Brandt’s cormorants reflects the
status of the forage fish they feed on, according to Dan Robinette of Point
gray whales now use the Bay as a feeding stopover, while long-absent harbor
porpoises have returned and bottlenose dolphins have arrived, reported Tim
Markowitz of the Marine Mammal Center.
Boosting Chinook Salmon
Johnson of the National Marine Fisheries Service set out to learn why tiny
Chinook salmon only make it all the way to the San Francisco Bay in really wet
years. Pursuing the question led to unexpected discoveries.
cool finding is that flow had a pretty important role in the number of babies
that could be produced for a given number of spawners,” said Johnson, after
presenting this work during a State of the Estuary Conference plenary. “The
habitat could produce a lot more in a high flow year.”
state goal is to allow at least 122,000 to 180,000 adults per year to escape
the fishery and return to the spawn, which is fittingly dubbed escapement.
Johnson found that in years
when salmon returns exceeded the state criteria
for escapement, production of babies was far higher. “If you double escapement,
it makes a very big difference,” she said. “This shows there’s a lot more
capacity for juvenile salmon production than we thought was in the system.”
Monitoring Wetlands Recovery
the Bay’s shoreline against rising waters and storm surges will require 100,000
acres of tidal marsh by 2030. “Monitoring supports that effort,” said Xavier
Fernandez of the San Francisco Bay Regional Water Quality Control Board at the
State of the Estuary Conference. “Looking at the past guides the future.”
Halsing, who leads the South Bay Salt Pond Restoration Project, is eager to
participate. “We have benchmark sites, project sites, and monitoring data,”
Halsing said. “Our goal is to share all that with the restoration community.”
unknown that would benefit from regional monitoring involves sediment needed to
rebuild tidal marsh in former salt ponds. “We’re working on it,” said BCDC’s Brenda
Goeden, “but we don’t know how much is coming into the system or how much we
need to maintain habitats.”
are various sediment monitoring efforts but they’re not necessarily connected,”
said Jeremy Lowe with the San Francisco Estuary Institute. “We should connect
for launching the Wetland Regional Monitoring Program include funding, a common
data management system, and standardized protocols. “If everyone collects data
the same way, everyone can use it,” said Rachel Tertes with the Don Edwards San
Francisco Bay Wildlife Refuge.
on the conference panel stressed that regional monitoring will not replace
project by project monitoring. “We have too many project specific questions,”
said Luisa Valiela who leads regional Clean Water Act programs for the U.S.
Environmental Protection Agency.
Sky Sensors More Sensitive
a State of the Estuary Conference session on new and emerging remote-sensing
technologies, Tony Hale of the San Francisco Estuary Institute sang their
praises. “New technologies are allowing us to see the landscape in different
ways,” Hale said later in an interview.
uses a fleet of three drones to do things like survey trash in creeks or
monitor wetland vegetation. “It really helps for monitoring restoration
projects in hard-to-reach areas,” said Pete Kauhanen, SFEI’s resident drone
Later in the session, UC Berkeley professor Iryna Dronova discussed new applications of remote sensing for mapping and monitoring vegetation. Of the more than 1,900 satellites orbiting the Earth, she noted, nearly 700 are used primarily for Earth observation and Earth science.
In a novel twist, Mark Marvin-DiPasquale of the U.S. Geological Survey presented a method of using satellite data combined with boat-based monitoring of the Delta to measure mercury from space. “Once you start making those connections [with remote sensing data], the question becomes, how far can we take it,” he said.
State of the Estuary Report 2019 Update on Fish
State of the Estuary Report 2019 Update on Tidal Marsh
Related Prior ESTUARY Stories
Marsh Mice Not So Picky, December 2019
Drones Pilot Vegetation Mapping, Sept 2019
Tough Year for Gray Whales and other Marine Mammals, August 2019
Putah Creek Pipeline for Salmon, March 2019
Spring-Run Salmon Need More than Simple Answers, Sept 2108
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Top Photo: Noah Berger