State of the Estuary Report 2015

State of the Estuary Report 2015

Accessing the Report

The Report as a Flipbook
The flipbook integrates features such as text searching, bookmarking, and new enhancements, such as interactive charts and data stories.

The Report as a PDF

The Executive Summary as a PDF
If you wish to take the report “to go,” then a PDF offers the best form for printing and emailing.

icon-soter-med

The Report in Motion

A Video Summary

INTERACTIVE ELEMENTS

We have crafted interactive graphs, charts, and data stories, all designed to bring some of the most salient information to life. You can find these interactive elements in the forthcoming eBook itself and via the following links:

Water

The Freshwater Flows data story relates the history of water management and drought in the Bay and Delta.

Habitat

Marsh is a home to many key species in both the Bay and Delta. A story map guides you through a comparison of changes to Bay and Delta marshland.

People

The tale of Bay Area stewardship of our drinking water since 1986 is remarkable for its conservation improvements and its ongoing challenges.

Summary of Estuary Health 2015


This table offers a brief, simplified summary of the 80 pages of information that appear in the report. The report, in turn, is based on painstaking work to assess the status and trends of the 33 indicators of estuary health listed below by teams engaging more than 100 scientists.

Legend
Status
Trend:
Improving No Change Deteriorating Mixed
good fair poor upward stock-vector-orange-yellow-arrows-arrowheads-pointing-up-down-left-and-right-up-down-left-right-buttons-2704459701 stock-vector-red-arrows-arrowheads-pointing-up-down-left-and-right-up-down-left-right-buttons-270445970.png threeicons

goldengate-41Water

Water
Bay

Status
Trend
Delta

Status
Trend
At-A-Glance

Safe for Swimming
Conditions are excellent at most Estuary beaches most of the time. Conditions have been poor at 7% of beaches in summer, and 27% of beaches in wet weather at times during recent years.

Safe for Aquatic Life
ESTUARY-WIDE
Estuary water quality is much better than 40 years ago, but the rate of improvement has slowed. Mercury, invasive species, pesticides, and trash are still problems. Improvement has been achieved for PBDEs and copper. Many potentially harmful chemicals have yet to be assessed.

Fish Safe to Eat
ESTUARY-WIDE
fair
no change
Limited consumption of most popular Estuary fish species is advised due to contamination from two legacy pollutants (mercury and PCBs). Routine monitoring in place since 1994 has shown no declines in these contaminants.

Fresh Water Inflow
ESTUARY-WIDE
poor
mixed
The amounts and variability of freshwater inflow to the Estuary have been substantially reduced, resulting in degradation of habitat conditions and ecological function in the Estuary.

™-FL_Suisun_Marsh-1893Habitat

Habitat
Bay

Status
Trend
Delta

Status
Trend
At-A-Glance

open water habitat
Open Water Habitat
poor
mixed
poor
down
In Suisun Bay, good quality, low salinity habitat occurs too infrequently, and for too short a time, to support flow-dependent organisms and the estuarine food web. In Delta channel habitats, net downstream flow is too low to support native fish species.

eelgrass
Eelgrass
poor
improving
 
 
The extent of eelgrass beds in the Estuary has increased, but is highly variable year to-year. The current total acreage is significantly less than the estimated maximum potential extent.

eelgrass
Tidal Marsh
fair
improving
poor
no change
Delta marshes have been lost and fragmented to a much greater degree than Bay marshes, despite covering a greater area historically. Restoration efforts have made a significant impact on Bay habitats, but are only just getting underway in the Delta.

Egret_VoleWildlife

Wildlife
Bay

Status
Trend
Delta

Status
Trend
At-A-Glance

Benthic Invertebrates
Benthic Invertebrates
 
 
fair
mixed
The benthic community at the foundation of the food web still includes many native species, but there are now many non-native species present as well. In some places, most individual benthic organisms are non-native.
Please visit the Estuaries Portal to learn additional information about the benthic monitoring program.

Fish
Fish
good
mixed
poor
Deteriorating
The fish community differs across the Estuary with increasingly poor conditions toward the upper Estuary. Native fish abundance in the brackish and fresh upper Estuary has declined markedly during the past three decades and is in poor condition.

Harbor Seals
Harbor Seals
fair
no change
 
 
Harbor seal numbers in the Bay are relatively stable, but have not increased in tandem with coastal populations.

Wintering Waterfowl
Wintering Waterfowl
fair
mixed
 
 
Wintering dabbling duck populations are strongly increasing across all parts of San Francisco Bay. Wintering diving duck populations are strongly decreasing in Central and North Bays but remain stable in the South Bay.

Breeding Waterfowl
Breeding Waterfowl
 
 
fair
Deteriorating
Populations of dabbling ducks that breed in the Estuary are mostly decreasing across Suisun Marsh and the Delta. Less common dabblers (non-Mallards) are increasing in the Delta.

Shorebirds
Shorebirds
fair
mixed
 
 
The Estuary’s population of large shorebirds is declining, especially in the South Bay. In the Central and North Bay, populations of medium and small shorebirds are stable or increasing, while in the South Bay they are on the decline.

Herons & Egrets
Herons & Egrets
fair
mixed
 
 
Heron and egret nest density is increasing over the long term. Nest success, in terms of fledged chicks, is relatively stable. Subregions reveal more complex patterns.

Tidal Marsh Birds
Tidal Marsh Birds
fair
improving
 
 
Tidal marsh bird densities are increasing for two of three species. As restored marshes mature, they are supporting more resident marsh birds.

Ridgway’s Rail
Ridgway’s Rail
poor
mixed
 
 
In the North Bay, endangered Ridgway’s rail populations have rebounded since a 2007-2009 decline. South Bay populations have stabilized at low levels after a similar decline, but not rebounded.

migrationProcesses

Processes
Bay

Status
Trend
Delta

Status
Trend
At-A-Glance

Migration Space
Migration Space
ESTUARY-WIDE
poor
No Data
Most land around the Estuary available for estuarine habitats to migrate landward, and accommodate higher sea levels, has been developed. Very little of the undeveloped portion is protected.

Beneficial Floods
Beneficial Floods
poor
mixed
poor
mixed
Flood flow events are now too infrequent, too small and too short in the Estuary to support important ecological processes. Dams, levees and water diversions have cut high volume inflows and beneficial inundation of the Yolo Bypass floodplain.

Zooplankton as Food
Zooplankton as Food
 
 
fair
mixed
The abundance of fish varies across the Upper Estuary. In the historically productive marsh and open water zones, small forage fish are declining, but in the Delta beach zone, they are increasing.

Fish as Food
Fish as Food
 
 
fair
Deteriorating
The abundance of fish varies across the Upper Estuary. In the historically productive marsh and open water zones, small forage fish are declining, but in the Delta beach zone, they are increasing.

Cormorant Chicks Raised
Cormorant Chicks Raised
good
no change
 
 
The breeding success of Brandt’s cormorants in recent years indicates that they are finding enough food in the open waters of the Estuary to feed their young, following a severe decline in success from 2009-2012.

Heron & Egret Chicks Raised
Heron & Egret Chicks Raised
fair
mixed
 
 
Heron and egret brood size is relatively stable across the Bay.

SCWA_recycled_water_pondPeople

People
Bay

Status
Trend
Delta

Status
Trend
At-A-Glance

Urban Water Use
Urban Water Use
fair
improving
 
 
In the Bay Area, urban water conservation efforts have lowered water use while population has increased. Short-term water use reductions in response to the drought have exceeded State-mandated targets but they may be short-lived.

Recycled Water Use
Recycled Water Use
fair
improving
 
 
The Bay Area currently offsets 5% of its urban water demand with recycled water, but lags behind other urban centers in the state.

Trail Access
Trail Access
fair
improving
 
 
In recent years, public access to Bay and Delta trail systems has steadily increased.

Technical Appendices

For the report indicators, our science contributors developed individual technical appendices, which you will find embedded in the above “Summary of Estuary Health 2015.” If it interests you, we also feature a comprehensive collection of all appendices.

Key Messages

How healthy is the Estuary?

So, what are the details of this health report? The status of half of the Delta and Suisun indicators is fair (including water quality and the organisms low in the food web). The other half are in poor condition (including freshwater inflows, beneficial flooding, open water and tidal marsh habitats, and fish communities). Most of these parts of the Delta and Suisun ecosystem are deteriorating over time or show mixed trends across subregions.
In contrast, the status of most Bay indicators is fair, including water quality, tidal marsh habitat, wildlife populations from harbor seals to birds, and human stewardship of the environment from trash clean up to water conservation. Bay fish and the birds that feed on them in the marine waters are even in good condition. Most of these parts of the San Francisco Bay ecosystem are either improving or have mixed trends across subregions.

Why are the Delta and Suisun Bay in critical condition? Why is San Francisco Bay in better condition?

The Bay is healthier by comparison to the Delta due to less ecosystem alteration by modern humans. There are three main causes of these impacts to ecosystem health: habitat loss and fragmentation, interruption of the ecological and physical processes associated with vibrant habitats, and the invasion of nonnative species.
Over the last 200 years, California’s Delta has become one of the most hydrologically modified deltas in the world. We’ve converted wetlands to farmland and altered a landscape once dominated by tidal marsh — a vital form of habitat — into a place dominated by levees, agricultural land, and channelized waterways. Flooding needed to move nutrients and sediments has also been limited. With growing water supply demands, the Delta has been further shaped to suit population and economic needs, such that ⅓ of all water entering the Delta never enters the Bay.
Restoration efforts are further along in the Bay where marshlands are once again defining significant portions of the Bay margins. But the Delta’s compromised ecology and hydrology may have made the region more vulnerable to invasions by non-native species, leaving parts of the system — especially the South Delta — a hostile environment for threatened native species.

Can we make the Estuary healthy?

Improvements in the status of several parts of the ecosystem show that we are very successful at restoring ecosystem health when we choose to make that investment. Water quality has improved over the last few decades due to improved management and regulation. Some legacy contaminants remain a problem, so managers are focusing on reducing inputs from urban runoff. Focused collaboration along with significant funding have resulted in large gains in tidal marsh restoration over last two decades, and improvements in marsh-dependent wildlife populations are now detectable as restored marshes mature. Investments in water conservation and recycling in urban areas are reducing demand for potable water, even while our population is increasing.

What will it take to achieve a health Bay and Delta?

The mixed results of this assessment in different areas of the Estuary indicate that we are not be doing enough to restore and maintain ecosystem health. A bolder approach will be needed to recover from past and ongoing impacts, especially since future impacts from climate change further jeopardize the ecosystem.
The Upper Estuary will require significant investment in restoring critical physical processes (notably freshwater inflows and floods) and habitats, as well as managing non-native species and preventing new arrivals. This will also require much greater efficiencies in human use of the system’s fresh water, as well as changes in upstream water management and policy, to make the conserved water available to nourish the Estuary.
The Bay’s wetlands are also at risk unless we take a new watershed-based, regional approach to managing sediment and fresh water as essential resources, and also make room for tidal wetlands to migrate landward. Wildlife conservation efforts should aim to ensure successful reproduction and habitat connectivity over time as climate change alters landscapes.
In short, the physical and biological processes that operate at the foundations of estuarine health are deeply damaged and must be fixed if we are to retain our native plants and animals, wetlands that protect shorelines, recreational opportunities, and clean water.

NO