THE BAY INSTITUTE Ecological Scorecard SAN FRANCISCO BAY INDEX 2003 © 2003 The Bay Institute of San Francisco The Bay Institute (TBI) is a non-profit research, education and advocacy organization dedicated to protecting and restoring the ecosystems of San Francisco Bay, the Sacramento-San Joaquin Delta, and the estuary’s tributary rivers, streams, and watersheds. Since 1981, TBI’s policy and scientific experts have worked to secure stronger protections for endangered species and habitats; improve water quality; reform how California manages its water resources; and promote comprehensive ecological restoration from the Sierra to the sea. To order copies of the 2003 Bay Index, or a CD of the report and the Technical Appendix, contact: The Bay Institute 500 Palm Drive, Suite 200 Novato, CA 94949 Phone: (415) 506-0150 Fax: (415) 506-0155 www.bay.org The entire 2003 Bay Index report and Technical Appendix can also be downloaded from our website at www.bay.org. The 2003 San Francisco Bay Index, and the Bay-Delta Ecological Scorecard Project of which it is a part, were made possible by the generous financial support of the Compton Foundation, Inc.; the Mary A. Crocker Trust; the Fred Gellert Family Foundation; the Richard and Rhoda Goldman Fund; the William and Flora Hewlett Foundation; the Marin Community Foundation; the Rose Foundation for Communities and the Environment; the San Francisco Foundation (Switzer Environmental Leadership Program); the San Francisco Estuary Project; the U.S. Fish and Wildlife Service; the Weeden Foundation; and the Dean Witter Foundation, as well as individual supporters of the Bay Institute. Cover photo: Napa Slough, by David Sanger. Ecological Scorecard San Francisco Bay Index Habitat long- Bay habitat loss is slowly being ↓ term D+ reversed, but it could take nearly 200 years to reach the tidal marsh short- Score = 32 restoration goal. term ↑ Freshwater Inflow long- Reduced inflows are still degrading ↓ term D the Bay ecosystem, and recent gains from wetter years and new standards short- Score = 29 are being eroded term ↓ Water Quality long- Open waters are cleaner, but ↑ term C standards are not met in parts of the Bay. Toxic sediments and short- Score = 55 storm runoff are a major problem. term ↔ Food Web long- Plankton levels in the upper Bay ↓ term F have crashed, reducing food sources for fish and birds. Alien species are short- Score = 10 locally dominant. term ↔ Grades based on data Shellfish long- from 2000-2003 period Crab and shrimp numbers are ↓ term B- increasing, but commercial harvest is short- A Excellent still down from previous high levels. Score = 63 term ↑ B Good Fish ↓ long- C Fair After a long decline, fish popula- term C- tions are stable at low levels, but short- Poor some species are still endangered. D Score = 39 term ↔ F Critical Fishable-Swimmable-Drinkable long- ↓ term Trends over time Fish are harder to catch, and D+ unsafe to eat. Beach closures are up, Long term= past 25 years or more short- Score = 31 drinking water violations are down. ↔ Short term = past five years term Stewardship long- improving ↑ Water conservation, pollution ↓ term - limits, monitoring, and restoration ↓ declining C short- Score = 43 efforts are finally underway, but ↔ progress is slow. term ↔ stable i ii • ECOLOGICAL SCORECARD • BAY INDEX San Francisco Bay Index Executive Summary an Francisco Bay is a unique national Many efforts are underway to Streasure. The largest estuary—where improve the Bay’s health. The Bay Institute’s ocean and fresh water meet—on the west Ecological Scorecard is intended to improve coast of the United States provides habitat for our understanding of how the entire Bay hundreds of plant and animal species, many watershed is doing, to monitor how effective found nowhere else in the world. The Bay our stewardship of this vital resource is, and supplies seafood for businesses and anglers. to identify future directions for management, Its watershed is a major source of water for monitoring, and research. The 2003 Bay cities and agriculture. Residents and tourists Index focuses on the Bay itself, which is the sail and swim in its waters, play along its first of four major ecological regions of the shoreline and tributary creeks, and value its estuary—Bay, Delta, San Joaquin River and wildlife and scenic qualities. Sacramento River—to be assessed as part of But the Bay’s vital signs are not the Ecological Scorecard project. good. Over the last century, once abundant The Scorecard’s Bay Index uses sci- native fish and wildlife populations have ence-based indicators to grade the condition declined drastically, while harmful alien of the Bay region: how well its ecological re- species have invaded the Bay. The amounts sources are faring, how much human activi- of wetland habitat and freshwater flows into ties are harming or helping the Bay, and how the Bay have decreased dramatically, while human uses of the Bay’s resources are af- pollution levels have risen. Commercial and fected by the Bay’s health. These indicators recreational fisheries have collapsed, and are combined into eight Indexes that track the those fish that are caught in the Bay are not Bay’s environment (Habitat, Freshwater In- safe to eat. The fair to poor grades reported in flow, Water Quality), its fish and wildlife the 2003 Bay Index reflect this long-term (Food Web, Shellfish, Fish), our management decline in the Bay region’s ecological of its resources (Stewardship), and its direct health—but the current situation is not all value to the people who use it (Fishable- bleak. In most cases, the decline has been Swimmable-Drinkable). The grading system halted and short-term conditions are compares current conditions in the Bay and relatively stable. In some cases, such as its watershed to historical conditions, envi- habitat and shellfish populations, there have ronmental and public health standards, and been small but noticeable improvements. restoration targets. iii iv • ECOLOGICAL SCORECARD • BAY INDEX Long-term Short-term Grade Score Trend Trend D+ 32 ↓ ↑ San Francisco Bay Index Habitat Wetlands, mudflats, and riparian • Tidal marsh area decreased by • The recent acquisition of South areas are rich sources of food and 78% during the last 150 years, Bay salt ponds, following nutrients, and provide critical from 190,000 acres to just similar efforts in the North spawning, nesting, and rearing 40,000 acres. Bay, created a unique habitat for the Bay’s fish and opportunity to restore up • Tidal mudflats decreased by wildlife species. These habitats to 23,000 acres of tidal marsh 42% in the same period. also improve water quality and around the Bay. Wetland flood control, and support birding, • Seasonal wetlands decreased acquisitions since 1997 total fishing, hunting, and other by nearly 75% over the 150- 40,000 acres, and at least recreational activities. Converting year period. two-thirds of these acres are these areas for agriculture, salt slated for restoration in the • Riparian habitat decreased production, and urban develop- next 30 years. 95% along the Bay margins, ment has reduced the Bay’s and 84% throughout the entire •During the past 5 years, almost productivity and restricted the Bay region’s watershed, from 500 acres of non-tidal diked amount of habitat available for use its full extent 150 years ago. wetlands have been created or by endangered plants and animals. enhanced, nearly 3% of the • Since 1998, restoration of 1,700 target for this habitat type. acres increased tidal marsh habitat by more than 4%. At this rate, it will take nearly 200 years to achieve the 50-100 year targets set for Bay tidal marsh restoration by the Baylands Habitat Goals Project. Habitat Index The Habitat Index aggregates the results of the tidal marsh, tidal mudflat, seasonal wetland, and riparian habitat indicators. v Long-term Short-term Grade Score Trend Trend D29 ↓ ↓ San Francisco Bay Index Freshwater Inflow The amount and timing of • In 2002, a “below normal” year • Seasonal variation in fresh freshwater inflow to San Francisco in the Bay’s watershed, the Bay water inflow—high flows in Bay defines the quality and received only the amount of spring and lower flows later quantity of its estuarine habitat. freshwater as expected in a in the year—are an important Flows transport organisms and “critically dry” year. environmental signal for many nutrients, improve water quality, Bay species. This variation was • Freshwater flow during the and provide the low salinity reduced by 46% in 2002, com- ecologically sensitive spring habitat on which many Bay species pared to historic conditions. period decreased by as much depend. Irrigating the Central as 75% since 1940. In 2002, • Peak flows, which periodically Valley, constructing a massive only 32% of the spring runoff freshen Bay waters, occurred system of reservoirs and canals, reached the Bay, still an for only eleven days in 2002, and exporting water directly from improvement compared to compared to the expected 58 the rivers and Delta have reduced spring inflows during the days of peak flows under the amount of freshwater reaching 1987-1992 drought. historic conditions. the Bay, and changed its timing. • Spring inflows are extremely • The 1940-94 downward trend • In 2002, just over 50% of total important to Bay fish. In 2002, in the Freshwater Inflow Index annual runoff from the reduced spring inflows shifted reflected increases in upstream Sacramento-San Joaquin low salinity habitat upstream water diversions. Wetter watersheds reached the Bay. by nearly 15 kilometers hydrologic conditions and • In recent years, reduced (9 miles) compared to historic increased flow requirements freshwater inflow cut the conditions, corresponding to a after 1994 temporarily frequency of “wet” years for predicted three-fold decrease improved Bay flow condi- the Bay by 50% and imposed in the abundance of several tions, but the trend has been drought conditions more Bay fish species.
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