bay ecology guide - Environmental Volunteers
Transcription
bay ecology guide - Environmental Volunteers
BAY ECOLOGYGUIDE great blue heron ENVIRONMENTAL VOTUNTEERS@ ggZLEastBayshoreRoad, Palo Alto, CA 94303 (650)961-0545/info@EVols.org -, _ 2048 C orporate C t S an Jose, C A 9513i w w w .magel l anw orl d.com Volunteersgratefully acknowledges Environmental MagellanWest,LLC for printing this guide. EnvironmentalVolunteers- Bay EcologyEV Training Guide EV M i s s i on .............. EnvironmentalLearningGoals Bay EcologyGuide Objective I n t r o d u c ti o n............ Bay.......... A GeologicalHistory of SanFrancisco How the BayWas Formed............. W a te rC o n d i ti o n s............... SomeBasicEcologicalConcepts. BayEcosystems............... An Overviewof SanFrancisco Introduced Species About Birds Open Water Estuary Ecosystem,Flora and Fauna Mud Flat Ecosystem,Flora and Fauna Salt Marsh Ecosystem,Flora and Fauna Salt Pond Ecosystem,Flora and Fauna Upland Ecosystem,Flora and Fauna Bay.......... F{umanInteractionwith SanFrancisco Human History Effectof Human Impact Striving to Savethe Bay Destructionof Wildlife Declinein Water Quality Climatic Changes RecreationLoss EarthquakeHazard ...............i ........i ........... i ... ....... i .....page 1 .page1 .............page 1 .......pages2 - 3 pages3 - 4 pages4 - 5 pages5 - 7 pages7 - 8 pages8 - 11 pageL1 pages12- 73 ...............pages 13- 17 pages13 -14 pagesL5- 16 page 17 : i::!li3i;1" H-;:'3J1':il:",LT:'l'i;;;;.;";;il,;s Beforethe ClassroomVisit Doing the Introduction SuggestedLearning Stations Closing Presentation Glossary.. Reading Suggested SanFranciscoBayResources Bibliography......,..... With SpecialThmtksto: L99LEducationCommittee: BarbaraCallison,chair Buffy Caulkins JaneHall Nancy Rubin Pages20'22 ..............page23 ...............pages23 -25 page25 Editor Karen Meisenheimer Copy Editor jan Whitmer Illustrations Courtesy:SanFranciscoBay National Wildlife Refuge,SnltMarshManunl EVS MISSION The Environmental Volunteers mission is to promote understanding of, and responsibility for, the environmentthrough hands-onscienceeducation. The Environmental Volunteersworks to achievethis mission by: . encouragingcommunity awarenessof the interrelationshipsof humans with the environment, . giving those reachedthe tools to be able to make informed decisionsabout the environment, . fostering in the community an attitude of stewardshipand responsibility for the environment. ENVIRONMENTAL LEARNING GOALS Environmental education leads studentsto discoverthat all living things, including people, are interdependent.We must cooperatein using and reusingour limited resources,which give and sustain all life on earth. The following five-fingered,"hands-on"approachto environmentaleducationis the basisof the EVs teachinggoals.Finger one is sensoryawarenessfor the diversity of the world around us; finger two representsthe values we hold, as well as thosethat needto be developed;the third finger is an awarenessof historical changesand a senseof continuity;finger four symbolizesthe interdependency of all things in our world; and finger five remindsus of our needto fostera senseof stewardship toward all life. The EVsbelievethat the bestmethod for leaming is through hands-onand other participatorymethods of teaching.EV materials are organized to enhancethis style of teaching.Our leaming materials foster the processskills of observing,comparing, ordering, relating, inferring, applying, categorizingand communicating.The sevenbasicconceptsof ecologyare easilytaught through the use of EV materials. The California state framework themes(currently undergoing a revision to fit the newest science standards),energy,stability,evolution,patternsof change,scaleand structure,and systemsand interactionscanbe readily presentedthrough our programs. BAY ECOLOGY GUIDE OBJECTIVES This guide is intended to further understanding of the Environmental VolunteersBayEcologyProgrnm and leaming stationactivities.Through the use of this guide and the suggestedreadings,volunteers will be ableto better understand,and generatein othersan appreciationfor the Bay'secology,speci{ic organismsand human interaction with the environment. INTRODUCTION The SanFranciscoBay is a rich and complexecosystem.It is composedof five basicnatural communities:open water estuary,mud flat, salt marsh (composedof both seasonaland tidal wetlands), salt pond, and a drier upland area.Thesemakeup the natural environmentof SanFranciscoBay.This estuaryis inhabitedby a diversepopulation of plants and animals.How this estuarywas formed, what specieslive here and why, and how humans have affectedthis unique environment will be briefly covered in this guide. A GEOLOGIC HISTORY OF SAN FRANCISCO BAY HOW THE BAY WAS FORMED Near the end of the Pliocene epoch (1 to 4 miilion years ago), a mountain range began forming along what is now the OaklandBerkeley hills. This upheaval caused the original bay to be sealed off 15,000yearsago from the ocean. At the same time the Sacramento River began forming a new route to the sea, cutting through the mountain range at what is now the Carquinez Strait. The southern end of the bay was creating new drainage patterns. The surface of the southern basin was crossed by bedrock ridges of 100 million-year-old Franciscan rock. These ridges rose from 200 to 300 feet. Some are currently buried beneath bay mud; others have formed familiar landmarks such as: Potrero San Palo, west of Richmond; Coyote Hills near Newark Angel and Alcatraz Islands; Red Rock near the San Rafael Bridge; Albany Hill and San Mateo Point. 10,000yearsago As the weather began to warm (225,000 years ago), the melting glaciers caused the sea to rise. The water crept through the Golden Gate, submerging the deep river gorge and valleys, and creating tidal marshes. Northern Santa Clara Valley was flooded by the encroaching ocean, forming the San Francisco Bay and depositing mud over the eroded bedrock. Some time after this flooding and mud deposition (about 100,000years ago), the weather cooled, glaciers advanced and the sea level lowered again, causing the newly-deposited mud to harden. About 20,000 years ago (after the last glacial period) the ocean reflooded the bay. The rate of flooding was fast in geologic terms, about one inch a year. For several thousand years sediments accumulated along the shallows; a second, thicker and softer young bay mud covered the ancient sea bed. The large expanse of tidal mud flats and marshes that were created by the accumulated sediments offered a haven for a diverse population of organisms. The watershed of the San Francisco Bay (estuary) covers 40 percent of California and extends northward to Oregon. An estuary is a partially enclosed body of water where the outflow from rivers meets and mixes with the influx of ocean water. As much as half of the surface water in California begins as rain or snow; at least one half of this water fall is diverted for use on farms, in factories and homes. The remainder flows through the delta to the largest estuary on the west coast of North America. 1 T}re deepest point in the San Francisco Bay is under the Golden Gate Bridge, where the submerged river cut a path to the ocean; water depth here is 350 feet. However, most of the bay is shallow. Seventy Percent is less than 18 feet deep, especially in the eastern and southern portions of the South Bay and the northern portions of San Pablo and Suisun Bays. Along the South Bay sediments are mixed with oyster shells, but elsewhere the estuary's bottom is coated with an ooze of fine silt - commonlv referred to as bav mud. Bay Guide page 1 A GEOLOGIC HISTORY OF SAN FRANCISCO BAY WATERCONDITIONS Hydrologists split San FranciscoBay into two distinct areas:a northem stretch from the delta through Suisun, San Pablo and Central Bays,where salinity levels are in{luenced by flows from the Sacramentoand San Joaquin Rivers. The second areaconsistsof [he South Bay which receiveslessfresh w^ater,about one-tenth less,than the northern area.Consequently,the South Bay's salinity levels are higher. During the summer months, becauseof evaporation, salinity may be higher in the bay than in the ocean. Semi-diurnal tides (two low and two high tides of unequal height approximately every 24 hours), affect the ecologyof the bay. An averageof 1250thousand acrefeet (onefourth of the bay's total volume) of seawater flows in and out of the bay during eachtide cycle. In contrast,the averageflow of freshwater into the estuary is about 50 thousand acre-feet. The bay had reached its maximum size about 10,000years ago and remained basically unchanged until the arrival of Spanishmissionariesand ranchers. SOME BASIC ECOLOGICAL CONCEPTS The bay is a valuable resourcefor all of us. Marshes serve as nafural air and water purifiers. Marsh plants can remove carbonmonotde from the air and produce large quantities of oxygen and carbon dioxide. They filter small amounts of sewageand other pollutants from the bay'swaters.We must rememberthat we, too, are a thread in the vast food web encompassingall the life residing in and around the bay. Understanding the following basic ecologicalconceptswill help us appreciatethe complexity of the web. 1. ALL LIVING THINGS DEPEND (directly or indirectly) ON EARTH, AIR, SUN AND WATER FOR SURVIVAL Earth:soiltype, topography,degreeof slope,pH, exposureand nutrients. Air:oxygen and other gases,wind, wind-bome particles. Sr:n:degreeof heat, Iight and energy. Water:ascontained within earth and air, as interacting with heat and light, as a solvent for nutrients and gases,as a medium for life forms, as a chemical to maintain intemal physiological functions. 2. LIVING THINGS ARE ADAPTED TO THEIR ENVIRONMENT; THEY CHANGE AND MAKE CHANGE (changeoccurs over time) Living organisms adapt, are modified by and interact with their physical environment. Living organismsmodify their physical surroundings by their various interactions. 3. LMNG THINGS DEPEND (directly or indirectly) ON OTHER LIVING THINGS FOR SURVIVAL Organisms interact with other organismsin order to survive. Organisms are interdependent. 4. AtL LIVING THINGS HAVE A NICHE WITHIN AN ECOSYSTEM Organisms have specific roles within an ecosystem,this createsa niche (specialrole and space)within their habitat. The variety of organismsin their niches and habitats within an ecosystem comprise a community. page 2 Bay Guide SOME BASIC ECOLOGICAL CONCEPTS 5 . LIVING THINGS ARE PRODUCERSOR CONSUMERS Producersprovide the basicenergywithin a food web. Theseare plants and are consurnedby first order consurners. Consumersmay eat live producers/consurneother live consumersor consulne dead or decayedorganiCmatter. Top consumersare predators and not usually prey; in a food pyramid they are at the top. 6. MATERIALS ARE RECYCIED, ENERGY IS TRANSFERRED IN DIFFERENT FORMS Organic and inorganic matter is transferred through a variety of methods and forms. Original energy from the sun is transferredby plants through photoslmthesis to first order consurners. Dead matter is broken down into simpler materialsby decomposers. Energynot utilized by various forms such as invertebrates,fungi and bacteria is releasedas heat. 7. HUMANS ARE DIRECTLY RESPONSIBLEFOR THE HEALTH OF THE PLANET Humans servea role within eachindividual's community and, hence, affect global environments. Becausehumans are capableof manipulating the environment, we can becomeaware of our impact on the community. Eachone of us must, to the best of our ability, make our impact positive by minimizing or eliminating environmental degradation. Source:Dr.Diane Conradson AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS An ecosystertis defined as "a community of plants and animals and the environment with which it is interrelated."An aerial view of the bay highlights distinct ecosystems:areasthat are coveredwith water and those that are not. Theseareasare divided into open water, salt marsh, mud flat, salt pond and upland. The bay itself is approximately5-5miles tgle grrd from 3 to 12 miles *ide. Theseecosystemswilt Ue describedalong with the associatedanimal and plant tife. INTRODUCEDSPECIES An estimated one hundred non-native speciesreproduce in the San Francisco Bay. Many exotic plants and anima]ghave-beenparticularly successfulin their adiptatioir to a ndv environment. The lack of competition and an abundant food supply has enabledthem to gain a stronghold in their particular niche.The quoyanacausespickleweed-destructionwith its burrows that isopod bphoeroma hastenerosion.The red foxVulpesfulaa feedson the eggsof the endangered California clapper rail (Rallrclongirostriil. AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS Many other introduced specieshave been successfulin adapting to the bay; some of them are listed below. SOME EXAMPLES OF INTRODUCED SPECIES Plants Brass buttons Cotula coronopifolia Star thistle Centaureasolstitialis Animals Invertebrates Soft-shelled clam Mya arenaria Japaneselittle-necked clam Tapes philippinarum Mud snail Illyanassa obsoleta Tube worm Streblospiobenedicti Vertebrates Stripsd bass Morone saxatilis Mosquito f.ish Gambusiaat't'inis Easternbullfrog Rana catesbeiana Ring-neckedpheasant Phasianuscholchicus Red fox Vulpes fulaa ABOUT THE BIRDS The variety of birds that inhabit the bay at various time is arnazing, A Iarge number spend the entire winter here; as many as 281 species have been identified. Some of the avian residents winter in the marshes, while others nest here but winter in warmer climates. The rest of the birds are migratory. It is estimated that over two million birds migrate through this South Bay area on the Pacific flyway, coming from their breeding grounds up north to winter in southern climates. Some birds are perrnanent residents; others winter in the marshes. Some only nest here; other species stop off briefly to rest and feed. Birds visiting and inhabiting the San Francisco Bay area are all specifically adapted to the type of food they eat and the type of habitat (open water, mud flat, salt marsh, salt pond, or upland) they occupy. Many of these adaptations are modifications to the birds' beaks and feet. Figure #1 shows the variety of these adaptations. Different species of birds usually do not compete for the same food. Shorebirds, though often feeding together, are not looking for the same food. One species may have a longer bill and probe deeper. Another species may have longer legs enabling it to feed in deeper water. Baylands birds can be loosely divided into four groups based on their food preferences: invertebrate and vertebrate eaters, filter feeders and scavengers. Some examples are listed below. page4 Bay Cuide AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS Invertebrate Eaters American avocet Recurairostraamericana Black-neckedstilt Himantopus mexicanus Willet Catoptrophorussemipalmatus // Marbled godwit Limosafedoa Killdeer Charadrius aocit'erus d' (Woodpecker) CLIMBING Western sandpiper Ereunetesmauri a \/* /r # - JS*MMTNGWEB WADING (Heron,Avocet) PERGHfNG(Sonsbird) Bhck-shouldered CATCHING PREY{Hawk, Owl) HOOKED (Baptors) Catching PreY,Meat Ea le r s,CH I S E LS HA P E D (Vvoodpeckers)Tree Drilling Vertebrate Eaters Northern harrier Circus cyaneus rHtcK (Finch) {ts"o*-, \ Seed Crushing / /\-;( - tF4. \- klte Ela-nus caeruleus Burrowing owl Athene cunicularia American kestrel Falco sparaerius Red-tailed hawk Buteojamaicensis Great egret Casmerodius albus Snowy egret Leucophoyxthula Great blue heron Ardea herodias Forester'stern Sternaforsteri Caspian tern Hydroplogne caspia Filter Feeders Shoveler Spatula clypeata LONG-SLENDER(ShoreBirds) Mallard Anas platyrhynchos Mud Probing, Crustacean Eaters Ruddy dwck Oxyura jamaicensis Cinnamon teal Anas cqanoptera SLIM SHARP (Swallows) Scavengers Gulls Larinae (aarieties) Western gull Larus occidentalis Turkey vulture Cathartesaura Figure #1 OPENWATERESTUARYECOSYSTEM Rather than being a true bay, San FranciscoBay is actually California's largest and best-known estuary. An estuary is a unique ecologicalsystem where fresh and salt water come together and mix. Salt water from the Pacific Oceanand fresh water from rivers are mixed by winds and tidal currents.The bay provides the only outlet to the sea for the 60,000-square-mile Central Valley and its rivers. Of the sixteen rivers that flow into San FranciscoBay, the principal ones are the Sacramentoand the San Joaquin Rivers. Bay water is termed brackish;its salinity is generally between 27,000to 29,000 parts per million (ppm) total salt. This compareswith 1,000ppm for drinking water and 34,000ppm for normal sea water. Fresh water feedsinto the bay from the San ]oaquin-SacramentoRiver systems.Water temperature averages about 62 " Fahrenheit, with extremes of 55 ' F in the winter and 70 o F in the summer. it Bay Cuide page5 AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS OPEN WATER ESTUARY ECOSYSTEM (contiNUed) Marshlands, tidal shallows, and deep-water areas produce a variety and abundance of fish and wild life. At low tide, 707o of the bay is less than 18 feet deep. However, there is a deep-water channel about a mile wide and about forty feet deep. This central channel extends almost to the town of Alviso. The open bay waters are home to many speciesof aquatic animals. Fish such as sharks, anchovies,sculpins, striped bass,and top smelt are born in the marshlands and shallow areasbordering the bay. The bay is a vital haven to many forms of wildlife. Experts estimate that as many as a million water fowl rest and feed in the marshes during the winter months. Migratory birds fly thousands of miles from their breeding grounds in Arctic Canada and Alaska to winter in Baja California or South America. For hundreds of years/ these birds have followed the Pacific flyway. It is estimatedthat the bay furnishes food, shelter and resting placesfor approximately 70Voof the water and shore birds which migrate along the Pacific fly*uy.In the 1940'san estimated 20 million migrating water fowl used the Pacific flyway. In 1990the count was estimated at 2.5 million; this reduction is due to a number of factors all of them related to human population density. About 75 different speciesof water and shore birds have been identified in the bav's area. OPENWATERESTUARYPLANT ANID A}IIIVT\L SPECIES Plants Diatoms (aarieties) Kelp Sea weed Enteromoraha Bird Migration Along the Pacific Flyway Animals Invertebrates Copepods Copepodnauplii Bay shrimp Crangon californiensis Gem clam Gemm gemma Vertebrates Leopard shark Triakis semifasciata Bat ray Mylobatis caliornica Starry flounder Platichthysstellatus Top smelt Atherinops at'finis Northern anchovy Engraulismordax Shiner surf perch Cymatogasteraggregata Three spined sticklebackGasterosteus aculeatus Staghorn sculpin Leptocottusarmatus Bay pipefish Syngnathusleptorhynchus Striped bass Morone saxatilis Forester'stern Sternaforsteri Caspian tern Hydroprogne caspia page6 Bay Cuide AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS OPENWATERESTUARYECOSYSTEMKontinued) Vertebrates Western grebe Aechmophorusoccidentalis Canvasback Aythya aalisineria Ruddy duck Oxyura jamaicensis Brown pelican Pelecanusoccidentalis California gull Larus californicus Double-crested cormorant Phalacrocoraxauritus Harbor seal Phocaaitulina MUD FLAT ECOSYSTEM Mud flats lie between the salt marsh and the deeper estuary waters. The casual observer may think there is little life present in this area. However, there is an abundanceof life in the mud. The burrows and siphon holes of benthic(bottom dwelling) animals proliferate in the mud. These include snails, clams, oystegs,mussels,isopods,crabs and polychaeteworrns. As plants decomposeto form detritus, they are eatenby these mud dwellers. These animals burrow to protect themselvesfrom wave action, dehydration and predators. In turn, these animals provide food for fish and other wildlife. The mud may be green due to a marine algae called sealettuce. 1< As soon as the tide goes out a feeding frenzy of shorebirds invades the mud flats. Various shore birds appear on the mud flats. The long legs of willets, avocetsand stilts hoid them well above the shallow water, whiie their long beaks probe for food. Hurrying along the exposed mud flats, the shorterlegged birds appear, the sandpipersand killdeers. Thesesmall birds dart about the mud looking for food. Avocets sweep the surface for small clams, piovers peck for worrns/ and dowitchers and willets probe the mud for different insectsand isopods. Only three of the shorebirdsseenat the baylands nest in the mud flats. They are the killdeer, avocet and black-neckedstilt. They are dependent on salt grass for their nesting areas. )\ MIID FLATPLANTAND ANIMAL SPECIES Plants Anaerobic bacteria Bacillus Sea lettuce UIaa lactuca Cord grass Spartinafoliosa Eel grass Zosteralatifolia Pickleweed Salicorniaeuropeaor airginica A nimals Invertebrates Diatoms (varieties) Fat innkeeper worm Urechis caupo \l Phoronid worms Phoronis(varieties) Nematodes(round worms) Tube worm Streblospiobenedicti Ghost shrimp Callianassacalifornienis Ribbed mussel Ischadiaumdemissum Mud snails llyanassaobsoleta *'*K \ 1?r' BayGuide % pageT AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS MUD FLAT PLANT AND ANIMAL SPECIES(continued) Animals Invertebrates Bent nose clam Macoma nasuta Ribbed mussel Modiolus demissus Mud crab Hemigrapsusoregonensis Vertebrates Killdeer Charadrius aociferus Black-bellied plover Squatarolasquatarola Short-billed dowitcher Limnodromusgriseus American avocet Recruuirostraamericana Black-neckedstilt Himantopus mexicanus Willet Catoptrophorus semipalmatus SALT MARSH ECOSYSTEM Salt marshesserve as a transition zone between the open water of the bay, mud flat and the dry upland areas.They are most noied for the abundant plant life that grows on their saltp water-logged soil. Salt marshesare subject to flooding by the high tides that occur twice every day. Salt marshesusually form in the zone between the highest high tide and the mean tide levels. The soil in a marsh is very salty. Most plants cannot grow in salty soils becausethe salt will literally suck fresh water right out of them. However, some plants called halophytes(salt-plant) have become adapted to a salt marsh. They either excretethe salt through special cells (sfomata) or are able to keep salt out of their root system.Halophytes are also adapted to being submergedby tidal waters part of the time. Theseplants, though adapted to getting their "feet" wet, are limited in the length of time they can be wet. Salt marsh plants grow in distinct zones.Each zone is dominated by a particular plant species.The distribution of each speciesis primarily determined by the duration of submersion.The amount of salt in the soil and water also determines plant distribution. Salt marshes are dominated by three plants: Cordgrassis one of the two most abundant plants in the marsh. It grows in the wettest part of the marsh closestto the bay waters, at the boundary between the mud flats and the sait marsh. This plant survives high salt concentrationsby distilling water through special glands called stomata, leaving salt crystals on the leaves.Cordgrassforms the first link in many food chains involving hundreds of animals that live in the bay. By fall, cordgrass has grown to a height of four feet and resemblesa small corn plant. When it dies, almost all of the grass decomposesinto minute particles called detritus, or "bay soup." Theseparticlesare food for bacteriaand young bay animals which, in turn, are eatenby larger forms of life. Cordgrassproduces five to ten times as much nutrient materials and oxygen per acre as wheat. page8 BayCuide AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS SALT MARSH ECOSYSTEM(continued) Pickleuseedis another dominant marsh plant, growing in a higher and drier marsh zone. This gray-green succulent begins growing where the cordgrass stops. The compressed leaves look like a series of slender pickles attached end to end. Pickleweed tolerates having its "feet" wet by high tides, but grows above the average iow tideline. The stored salt builds up in the "pickles" until fall, when the end "pickle" turns pink or red, dries up and breaks off- Pickleweed thrives in soil of up to 6Vosalinity. During the summer months you may seea conspicuous,bright orange hair growing on the pickleweed. These hairs are actually the stems of a parasitic plant called marshdodder.IL attachesitself to the pickleweed by inserting small knobs into the pickleweed which bring food from the pickleweed to the dodder. Salt grassgrows in the zone above pickleweed. Like cordgrass,it excretessalt from its leaves by means of special glands. Other plants also will grow in this zor\e,including the Australian salt bush (which provides shelter for the pygmy blue butterfly and food for its larvae), fat hen and alkali heath. Birds of prey that are dependent on the salt marshesfor their food are the black-shouldered kite, northern harrier, red-tailed hawk, American kestrel and burrowing owl. Their favorite diet is meadow mouse, ground squirrel, gopher and rabbit, aithough the kestrel will eat insects.Most of thesebirds prefer to nest in the foothills of SantaClara county., although the blackcrowned night and blue herons nest on Bair Island near Redwood City. The salt marshesare inhabited by several endangeredspecies,the California clapper rail, the red-bellied salt marsh harvest mouse, the black-shouldered kite, the pygmy blue butterfly. The clapper rail and harvest mouse may be observed during high tide when forced out of their habitats. Stands of cordgrassgrowing near the water's edge serve as nesting grounds for the endangeredCalifornia clapper rail. On slightly higher land among the pickleweed are the nests of waterfowl, salt marsh song sparrows and coots. The red-bellied salt marsh harvest mice are found nowhere else except in the San FranciscoBay marshlands.Thesemice make a nest of dry pickleweed and can drink salt water, excretingthe excesssalt in their urine. They serye as a major source of food for the northern harrier (a major predator of the salt marsh). Shrews and other mice speciesalso inhabit the same area. Shrews are the smaliest of the mammals living here. They feed on insects of all sizes and eat continuously,day and night. '{it\ 43 :-,-, Bay Guide page9 AN OVERVIEW OF SAN FRANCIqCO BAY ECOSYSTEMS SALT MARSH PLANT AND ANIMAL SPECIES Plants Algae Cordgrass Spartinafoliosa Pickleweed airginica and europea -Salicornia Marsh dodder Cuscutasallna Salt grass Distichlis spicata Sea arrowgrass Triglochin maritima Cl.ly dock Rumex crispus Alkali heath Frankenia grandifolia Gum plant Grindelia humitis Fat hen Atriplex patula Australian saltbush Atriplex semibaccata Fennel Foeniculum aulgare _r, t1ffi\ YtH g ,f naoo'1 O - f o- -- Animals Invertebrates BarnacleBalanus Salt marsh logquito Aedessquamiger,A. dorsalis Larvae Brine fly Ephydri Tiger swallowtail papilio rutulus Pygmy blue butterfly Brephidium oxilis Vertebrates pupa Mud goby Cleaelandiaiox _Long_jawmudsucker Gillichthys mirabillis Leopard shark Triakis semifasciata Flounder platichthyes flesui, p. stellatus American avocet Recurairostraamericana Black-neckedstilt Himantopus mexicanus Willet Catoptrophorussemipalmatus Marbled godwit Limosafedoa Killdeer Charadrius aociyerrs California clapper rail Rallus longirostris Sanderling Crocethiaalba Western sandpiper Ereunetesmauri Common goldeneye Bucephalaclangula Great egret Casmerodius albus S_nowyegret Leucophoyxthula Great blue heron Ardea herod,ias Black-crownednight heron Nycticorax nycticorax Shoveler Spatulaclypeata Mallard Anas platyrhynchos Cinnamon teal Anas cyanoptera Norther harrier Circus cvaneus Burrowing owl Speotytocunicularia Red-winged blackbird Agelaiusphoeniceus Song sparrow Melospiza-melodia White-crowned sparrow Zonotrichia leucohhrys Savannah sparrow passerculussandwichensis" Jack rabbit Lepus calit'ornicus ---EaGae AN OVERVIEW OF SAN FRANCISCO BAYECOSYSTEMS SALTMARSH PLANTAND AMMAL SPECIES(continued) Vertebrates Gontinu ed) Red-bellied harvest mouse Reithrodontomysraaiaentris Salt marsh harvest mouse Reithrodontomysmegalotis San Franciscogarter snake Thamnophiselegans Gopher snake Pituophis catenifer SALTPONDECOSYSTEM If you were to take an airplane ride over the southern end of the bay, you would notice a mosaic of different colored ponds. The different colors are due to the many varieties of algae and aerobic bacteria that thrive in varying concentrationsof brine (salty water). Generally, red water indicatesa very high level of salinity; the less saline ponds are blue or green. Naturally occurring salt-evaporationponds have been in existencefor centuries.Local Native Americans used the salt residue to barter for goods. In 1854the first man-madeponds were built by ]ohn Johnsonin Hayward. In 1936Leslie Salt Co. becamethe owner of these man-made salt ponds. Salt ponds comprise about sixty square miles of diked habitat. Although manmade, the salt pond habitat has become important to the survival of many organisms.Many speciesof wintering birds are dependent on the salt ponds for food. As the water evaporatesthe salinity increases;2 miilion tons of salt are produced annually in a processthat takes 5 to 7 years to complete.Salt grass can survive in the less salty ponds along with the insect, water boatman. As the salinity increasesfewer speciesare found that can survive. Bacteria,a specially adapted algae,brine shrimp and flies comprise the baseof the salt pond's food pyramid. Black-neckedstilts and avocetshunt for brine shrimp, while along the pond's edge snowy plovers snap up brine flies. Both avocet and black-neckedstilt populations have increasedbecauseof the additional food supplied by the ponds. The dried out ponds and the leveesalso provide valuabie nesting sites. SALT POND PLANT AIVDAlvIIv{r{LSPECIES Plants Algae Dunaliella salina Salt grass Distichlis spicata SALT POND PLANT AND AMMAL SPECIESkontinued) Animals Invertebrates Bacteria fuarieties) Brine shrimp Artemia salina Brine fly Ephydra Water boatman Arctocorixa interrupta Salt marsh mosquito Aedessollicitans Vertebrates Black-neckedstilt Himantopus mexicanus American avocet Recurairostraamericana Bay Guide page 11 AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS UPLAND ECOSYSTEM The San FranciscoBay and the surrounding land are no longer in a "natural" state. Human impact has forever altered the face of this environment. As a result of humans draining marsh land and also becauseof natural drainage, there is a large, surrounding, drier area around the bay called an upland environment. Many of the plants growing here are not natives, such as European grasses,eucalyptusand acacia.They have establisheda niche by being vigorous and aggressive,and not having much competition for space. The non-native red fox and ring-necked pheasant live alongside the native jack rabbit, gopher snake, ground squirrel and northern harrier. The snowy egret, great egret and the great blue heron build their nests on higher growing plants such as shrubs or trees.All of thesespeciesare adapted to the open, flat, dry and windy upland ecosystem. UPLAND ECOSYSTEM PLANT AND ANIMAL SPECIES PlanLs Bunch grass Wild oats Aaena fatua Sticky monkey flower Mimulus guttatus Mustard Brassicacampestris,B. nigra Plantain Plantago hirtella Curly dock Rumex crispus Hemlock Conium maculatum Fennel Foeniculum aulgare Soap root Chlorogalum pomeridianum Thistle Cirsium araense Gum plant Grindelia humilis Horehound Marrubium aulgare Coyote bush Baccharispilularis California laurel Umbellularia californica Alder Alnus oregona Animals Invertebrates Pyg*y blue butterfly Brephidiumoxilis Tiger swallowtall Papilio rutulus Cabbagebutterfly Pieris rapae Mosquito Aedessquaiger Crane fly Tipula triuittata Vertebrates Gopher snake Pituophis catenit'er Western fence lizard (blue belly) Sceloporusoccidentalis San Franciscogarter snake Thamnophiselegans Pigeon (rock dove) Columbialiaia White-crowned sparrow Zonotrichia leucophrys Savannah sparrow Passerculussandwichensis Barn swallow Hirundo rustica House finch Carpodacusmexicanus Brown towhee Pipilo fuscus page72 Bay Cuide AN OVERVIEW OF SAN FRANCISCO BAY ECOSYSTEMS (continued) UPLAND ECOSYSTEMPLANTAND ANIMAL SPECIES Vertebrates Loggerhead shrike Lamius ludoaiciannus Anna's hummingbird Calypteanna Northern harrier Circus cuaneus Red-tailedhawk Buteojamaicensis Burrowing owl Speotytocunicularia Turkey vulture Cathartesaura Black-tailed jackrabbit Lepus caliornicus Striped skunk Mephitis mephitis Ground squirrel Citellus beecheyi California vole Microtus californicus HUMAN INTERACTION WITH SAN FRANCISCO BAY HLIMAN HISTORY Native Americans inhabited the bay's shores for at least 3500 years. It is estimated that as many as 75,000 people inhabited the area of San Francisco Bay when the Spanish explorers first arrived. The abundance of food and the year-round mild climate offered these people the opportunity for a relatively rich and easy life. They left evidence of their existence in the remains of some 400 shell mounds scattered around the bay. However, their impact on the environment was minimal. In the last 150 years,alterations of the bay have not been so much from geologic forces as from human intervention. The original delta's 350,000acres of freshwater marsh were diked and planted with crops. Its waters have been severely polluted and over 60voof the bay has been filted with garbageor Ieveed off from tidal action. In 100years,the larger bay territory has decreased from 720 to 480 square miles. In the process,many fishery resourceshave been lost and valuablewildlife habitat and recreationspacehave been destroyedor altered.' Bay Cuide page13 HUMAN INTERACTION WITH SAN FRANCISCO BAY HUMAN HISTORY(continued) In 1769,the Spanishexplorer Gaspar de Portola, 63 men and 200 horses, camped on the north bank of San Francisquito Creek near the tree El Palo Alto. He was searchingfor Monterey Bay, but instead found San Francisco Bay. Five years later, in 1774,Captain Rivera and Father Palou planted a cross on the creek bank near this spot, considering it a fine site for a mission. San FrancisquitoCreek was navigable, so a landing was built about a half mile upstream from the bay. Lumber, hides and taliow were transported along the creek from the back country to be loaded aboard vesselsmoored at the landing. Materials were transported up the bay to the growing city of Yerba Buena which would soon become known as San Francisco. In 1851the Stateof California passedthe first of a seriesof statutes authorizing the salg of swamp and later tidelands. The object of the statute was to "reclaim" bay land which was considered worthless in its natural state. People took advantageof this law and began acquiring salt marshesand other bay land, which were routinely filled for the development of farms. The Gold Rush caused some of the earliest, major destruction of the California environment. The technique of hydraulic mining blasted hillsides with powerful jets of water. It is estimatedthat by "1884, when this processwas finally banned, over a billion cubic yards of sediment were washed downstream and deposited in the northern portions of the bay. Eventually sediments flowed southward causing massive population depletion of oyster beds (Seefigure #3 below). Key Salt marsh before 1800's Salt marsh today Open water today \/ -l /4 - San Francisco Bay ta? Be d w o o d Clly - t.,i.1 " " n 'o \{ 'r.\/ - \ \ Pato atro ] \ ' "")","')"* \ figure #3 page74 -:-- Bay Cuide HUMAN INTERACTION WITH SAN FRANCISCO BAY EFFECT OF HTIMAN IMPACT Ever since the first settlers hauled some dirt from the bottom of Telegraph Hill to fill in Yerba Buena Cove for a waterfront port, humans have been reshaping the bay's shore, extending it outward and changing it in various ways. Much of the financial district of San Francisco and the Marina District were once under water. Other cities soon followed San Francisco's example so that the bay's original area was diminished by filling and diking. Of the original 720 square miles of natural marshland, oniy about 75 square miles are left (Seefigure #3, page14).SanFranciscoBay was consideredby many to be largeenoughthat filling one small sectionwould not endangerit. San Franciscoand Oakland airports, FosterCity, the BayshoreFreeway and TreasureIsland are some examplesof developments built on filled lands to satisfy the needs of a mushrooming population. Major bayfill is often an accumulation of domestic garbage.There are more than nine garbagedisposal sites around the South Bay. Walls or leveesare built around some of the marshesand tidelands for disposal sites. The water is then drained out so garbagetrucks can dump their loads. After about eight feet of garbageis dumped at the site, two feet of dirt is put on top of the garbage.l-and used in this manner is called a "sanitary landfill." The disposal sites are not only unattractive but can be a source of poliution and representa loss of wetiand or mud flat habitat. It is estimatedthat over 64Voof landfiil sites are located on tide and marsh lands. Sometimesthe leveesare poorly built and refuse spiils into the bay. Since each of us adds oaerfour poundsof garbagedaily, methods must be found for disposing of our garbage.without continuing to fill or poilute the bay. Tlre San FranciscoBay is a giant receptaclefor the sewageof approximately 7.5 n-rillionpeople, for the pesticidewastes washed off of farm land, for the residue from rain-washed roads and parking lots and for the dischargesof industry. There are over 80 waste water outlets into the bay, discharging eight hundred miilion gallons of waste water daily. Waste water still includes many organic solids, as well as oil, grease,phosphates,mercury (in small amounts) organic chlorine, heavy metals,selenium,PCB'sand microorganismswhich are dumped directly into the shallow waters of the bay. A clirectrelationshipexistsbetweenthe amount of toxic material discharged into the bay and the lack of organismsessentialto the natural food chain. Tire bay is not only shrinking, it is also lowering. Each year the land mass sinks a couple of inches. Becauseof human and industrial consumption, the water table (underground water supply ) is being depleted much faster than it can be replaced;recent drought has only exacerbatedthe problem. The result is an increasein the intertidal mud flats and a change in the delicatebalance betrveenthe various bay ecosystems. Filling and adding wastewater to San FranciscoBay will continue to have dramatic effectson the surrounding environment and the organismsthat are on that environment.The following are just a few ways that the c'lependent degradationof the bay affectsthe quality of life for all. Bay Guide page15 HUMAN INTERACTION WITH SAN FRANCISCO BAY EFFECTOF HUMAN IMPACTkontinued) Destructionof Wildlife Fish and wiidlife can exist only where the habitat meets their needs.When salt marshesare destroyed,few speciesshow the ability to adapt to different habitats.If wetlands bordering the bay are destroyed,a high percentageof the birds migrating along the Pacific flyway may be jeopardized.California has lost more of its wetlands than any other state. More than 67voof San FranciscoBay's wetlands have vanished due to housing developments, airport runways/ garbage dumps, industrial parks, and marinas. Decline in Water Ouality and ChemistrJr Not only must animals' homes be preserved, but they must be maintained in an unpolluted condition. Bay filiing can result in chemical reactions which releasepollutants into the water severely reducing the amount of oxygen in the water, killing fish and other organisms. Storm sewers' general runoff during normal weather conditions will be treated before discharge into the bay. However, becauseof the increasedvolume of water during storms, some untreated storm water will be discharged directly into the bay. Toxins dumped down sewersduring dry weather may accumulateand be washed out into the bay during heavy rainfall. Another aspectof the change in the bay's chemistry is alteration in salinity Ievels due to increaseddemands for fresh water from growing populations and from agricuitural use which resulted in less fresh water for the bay. Climatic Changes If a major portion of the bay were filled, there would be changesin the climate. The wind would be slower since wind velocity is higher over water. Cooling summer breezeswould not blow as far south and east; temperafures would rise and smog would be intensified. RecreationLoss By the year 2020,a projected 15 million people will be living around ihe bay. Open spacefor hiking, boating, bird watching, and fishing will be in greater demand. The bay should be available as a place for all to visit and enjoy. Fortunately, an increasingamount of the bay's 276-mile shoreline is being made available to the public for thesepurposes. It is important that we keep these recreationareasin pristine condition. Earthquake Hazard Filled lands can look stable,but tend to sink as the soil particles shift and settle when they are shakenby an earthquake.This processis called IiquefactionBecausefilled areasare less stable, more damage can occur ro structuresbuilt on landfills. HTIMAN INTERACTION WITH SAN FRANCISCO BAY STRIVING TO SAVE T}IE BAY The 1960's initiated a period of environmental concern, typified by the establishment of the Bay Conservation and Development Commission (BCDC) by the Stateof California n'1967. Alarmed at the shrinking of the bay due to filling, the BCDC was interested in the preservation of the shoreline for public accessand marsh areas for wildlife. A small group of citizens recognized the value of South San FranciscoBay, and in 1968formed the South San FranciscoBay Planning, Conservation and National Wildlife Refuge Committee. As a result of the efforts of this and other grassroots organizations,Congressset aside money to buy 23,000acresfor San Francisco Bay National Wildlife Refuge in 1972.Another 1972 event, the amendment of the Federal Water Pollution Control Act, allowed $18 billion in grants for the construction and expansion of thousands of waste treatment plants. The tri-city (Palo AJto, Mountain View, Los Altos) Regional Water Quality Control Plant (RWQCP)began operation in October, 1972.The RWQCP has now increasedto include East Palo Alto, Los Altos Hills and Stanford University. This facility provides tertiary water treatment of sewage,designed to remove 9AVoto 97Voof the biochemical oxygen demand (the amount of dissolved oxygen required by bacteriato decomposeorganic matter), thereby increasing the amount of dissolved oxygen available to other organisms once the effluent is dischargedinto the bay. In 799'1,additional coagulating and filtering were added to produce approximately 1.5 million gallons of reclaimed water daily. Dischargeof metals has been reduced by 60% of the 1980levels. According to tests of untreated water for hazardous wastes,the RWQCP continues to find an alarming percentageof heavy metals and other toxins. Their advice is to save all household hazardous wastes for special hazardous waste collectiondays. Tighter government regulations now provide at least some control over where and how wetlands are developed. Developers are now required to preserve an equal amount of nafural area for any area that is developed. Two examples of the results of these regulations are Mountain View's Shoreline Park and Palo Alto's Bayfront Park. But the fight to save the bay is far from over, consider President Bush's desire to re-define wetlandwhich would exclude many areasfrom protection, and many wetlands just outside the San FranciscoBay National Wildlife Refuge boundaries are currently slated for development. Although many proposed developments seem small, the bay must be consideredas a single body of water, a complex ecosystem,in which seemingly minor fills or waste dischargeshave far-reaching and often devastatingeffects. Bay Guide page17 HOW TO DO AN INTRODUCTION AND CLOSING PRESENTATION AN EV CLASSROOM The initial impressionyou make at the beginningof a presentationsetsthe tone for your entire visit. Be sure you know your audience,keep your openinq interesting,informative and brief. The children's curiosity-shotrldbe piqiled enough:o th9{ are eagerto find out more. The examplesgivenhereire^to be used as a guide. It's bestto put your messagein your ownworrds this will make it yours, natural and more enjoyablefor you to do and, therefore,more interesting for your listeners. BEFORE YOU GETTO THE CIASSROOM HERE ARE SOME SUGGESTIONS o Use the Chief'sCheckList to guide you through the necessarysteps. . Call the teacherto give necessarypre-visit information and confirm dates, times and room number. o Know your topic o Settime limits for introduction,learningstationsand closing ' Outtine your objectives(desiredoutcomes)and communicatethis to your team. o Call your EV assistantsand confirm that they know what your objectivesare, what they are doing, where they're going , when they are to be there and who is picking up and droppong off the learning stations. VISIT- INTRODUCTION THECLASSROOM )F Introduce yourself, EV assistantsand the Environmental Volunteer organization. * Explain the words enuirlnmentand aolunteer. GradesK - 2 {. Use Salty, salt marsh harvest mouse puppet, as a way for Salty to tell a story about where he lives,how he survivesand about his neighbors. Grades 3 - 6 * Ask the children what they picture when you say SanFrancisco Bay (Using the aerialmap of the bay) (Older childrenshouldknow that our bay is really an estunry,a mix offresh and salt water.) * Show the map of the San FranciscoBay, surrounding water ways and ocean )t Ask them to imagine they are big birds that can fly high and seethe whole state of Califomia. ,T Ask one child to show the PacificOceanon the map, where their school or houseis located,the SierraNevada,the SanJoaquinand Sacramentorivers, and the San FranciscoBay. * * * Ask the children if they know where the bay's water comesfrom. Acknowledgeand encourageorderllr responses. * Offer additional information as neededabout fresh and salt water sources Explain the term estuary(write it on tfu board.) )F Ask how oceanwater is different from bay or river water. HOW TO DO A CLASSROOMINTRODUCTION AND CLOSING INTRODUCTIO N kontinued): * Discuss the differences between salt and fresh water. {. Ask sfudents if they would drink clean ocean or bay water. *Ask them if they can guess how plants and animals adapt to living in or near salt water. * Use the ryap_todiscussthe inJluenceof the ocean'swater on the bay and discussthe Golden Gate ( discussthe influenceof tides with older children,gr _ a d e4s-6 . ) :{. Using the map, discussthe influx of freshwater into the bay. {.Ask them where freshwater initially comesfrom that goesinto the bay. * Ask what kinds of plants and animals are found living in or near the bay. *Lead into learning station activities;be sure the classhas been divided into small groups. *Ark th. teacherto be the time keeperfor the leaming stations. LEARNINGSTATIONS {. GradesK - 2, use kits that allow for: Comparing and describingFeathers(MP - 09),Bay birds (Bl - 11),Fish Study (Bl - 06) SensoryexplorationFeelyboxes(Bl - 05),Mud (Bl - 07),Camou{lage(MP - 01). ,T Grades3 - 6, use kits that call for: Reasoning(why is this like this)Fish Study (Bl - 05),Bay Birds (Bl - 11),Feathers(MP - 09), Bay Banner (Bl - 02) Speculation(if this were to happen what would the result be?)Fbod Web (Bl - 03), Beaksand Food (Bl - 01), Wetland In A Pan (Bl - 12), Winging It (MP - 04), LoathsomeLiter (M - 07). CONCLUSION ,F -After leaming station activitiesare finished,allow time to ask children to tell one thing they leamed about the bay (you probably won't have time to ask every ctrilA f6r a response.)Or, ask a specificquestionabout eachof the stationspresented.Example:"\AIholives in the mud?" *lf th"r. will be a field trip, take time to give instructionsabout clothing, and appropriate field trip etiquette. *Mention somethingspecificfor them to Iook for on the field trip. (See lenrning station matrix) fl / r'--*-:- \ t --\ F** ,-#'b lilritul GLOSSARY Adaptation: ' u11adjustment to environmentalconditions; a modification of an organismor its parts that helps that plant or animal survive. Algae: tiny, non-seed-bearingaquaticplants with chlorophyll often maskedby a brown or red pigment. Benthos: animalsthat are in a bottom-dwelling community under a body of water. Bog: wet, spongy gtound, with soil composedmainly of decayedvegetablematter. Biodegradable: --- ---o the ,.upableof being broken down to simple compounds,especiallyinto harmlessproducts,by actionof microorganisms. Brackish: somewhat salty water, but'less salty than sea water' Carnivore: an organism (plant or animal) that eats meat' Consumer: plant matter' an organism that consumesmeat by preying on animals or consulnes Ctustacean: and breathethrough a classof arthropods that usually live in water, have hard exoskeletons, gills e.g',crabs,shrimp, and bamacles Decomposer: an organism (such as bacteria.o.tfulgt) that retumt,.o*qo-1:tsof &.i"!UV organic matter to ecological f""dittg on and breaking d6wn dead plants and animals. DeDendence: - -E the state of requiring something else for individual survival' Detritus: decayingbits of plant and/or animal remains(resemblesgooeymud sometimes)' Diurnal: active or occurring in the daytime' Ecology: ""the study of the interrelationship of organismsand their environments' Endangered: threatenedwith extinction' EStuary: r ,r !:l ^l raarl rrl rr -r, -.-l ^^-^ ^^l r water is regularlv a partially enclosedbody of water with inlets and outletswhere tidal salt -r,a$n+.i o mixed with freshwater' Extinct: an animal or plant speciesthat no longer exists' GLOSSARY Food chain: a sequenceof Livingorganismsinan ecologicalcommunity in which membersof one level feedon thosein the level below them and in fum are eatenby thosein the level abovethem, Food web: the totality of interactingfood chainsin an ecologicalcommunity. Habitat: the place where a plant or animal nafurally or normally lives, often characterizedby a dominant plant form or physical characteristic(the stream or forest habitat). Halophyte: a plant that is specially adapted to survive in salty soil (saltbush, pickleweed). Herbivore: an organism that eatsliving plants or their parts. Interdependency: mutual dependenceof a variety of speciesof organisms. Invertebrate: an animal without a backboneor spinal column. Larva (plural larvae): an immature stagethat most insectsand somewater animals pass through after hatching from an egg and beforebecominga pupa. Migration: the act of moving (usually seasonally)from one locality to anotherfor feeding or breeding Purposes. Mud flat: the salty soil area of land betweenthe lowest low and the highest low tide that is flooded with seawater daily and upon which very few plants grow. Nocturnal: active or occurring at night. Nutrients: the raw materialsnecessaryfor continuing life processes. Omnivore: an organism that eatsboth plant and animal material. Organism: a living thi.g. Plankton: aquatic plants (phytoplankton) and animals (zooplankton)that drift with the currents. Photosynthesis: p.o.esr of plants using light energy combinedwith carbondioxide and water to produce oxygenand simple sugars. GLOSSARY Pollution: contaminationof the environment,especiallywith human-madewastes. Predator: an animal (rarely a plant) that capturesand eatsanimals for food. Prey: an animal or plant hunted bv another for food. Producer: an organism(suchas a greenplant) which usessolarenergyto convert inorganicsubstancesinto food (i.e.,it doesnot have to eat)through the processof photosynthesis. Pup a : an insectin the non-feedingstage(usuallyimmobile) betweenthe larval and adult stage. Refuge: a place that provides food, shelter,and protectionfor the organismsthat live or migrate there. Salinity: the concentrationof salt in the water. Salt marsh: salt water wetland betweenterrestrialand marine ecosystems;salt marshesmav also be seasonalor tidal wetlands. Salt pond: a human-made,diked off, flat area full of salt water which evaporatesto produce salt. Slough: a swamp, marsh or pond which is part of an inlet under tidal in-fluence. Tide: the altemate rising and falling of the water in oceans,Bulfs, bays, and estuaries,occurring twice a day in Califomia, causedby the gravitational attraction of the sun and moon on the earth, occurring unequally at different placeson the earth. Upland: ground elevatedabovethe lowlands,marshlands,or rivers. Wetlands: areasthat, at least periodically, have waterlogged soils, support plants adapted to wet soil, and are coveredor occasionallysubmergedby water. Bogs,freshwaterand saltwatermarshes, and freshwater and saltwater swamps are examplesof wetlands. page 22 Bay Guide SUGGESTEDREADING Bakker, Elna.An IslnndCalledCalifornia.lg7l,IJnlersity of Califomia Press,Berkeley. Northem California Community College ATraael Course.1981, BayOdyssey, Capman,J. SanFrancisco Leaming Consortium. Comell, J. SharingNaturernith Children.7979,Ananda Publications,Nevada City, Califomia' of Nature.Tggl,DawnPublications,NevadaCity,Califomia Comell, J.SharingtheJoy 3rd edition, San FranciscoBay Wildlife Society, Conradson,Diane R. ExploringOur Baylnnds.1996 California. National Wildlife "EndangeredSpecies:Wild & Rare,"1987,Rangu Rick'sNatureScope. D. C. Federation,Washington, National Wildlife Federation. "Wading into Wetlands," 1986, RangerRick'sNatureScope. D.C. Washington, Jacobson,Yvorne. PassingFormsand Enduring Values.1984,TiogaPress,Menlo Park, Califomia. Pr oject Wil d. 1,985,Westem Regional Environmental Education Council. San FranciscoBay National Wildlife Refuge,SaltMarshMnnual,an educatlr'sguide.1990,U.S. Fish & Wildlife Service. WetlandsCurrianlum. 1990,SantaClara Audubon Society. SqnFranciscoBay Seasonal Smith, A. ,ed. Child Ecology,Grade3. TheBayandMarsh.1974,Chlld Ecology Ptess, Los Altos, California. Storer,John.Webof Life 1956,National AmericanLibrary, New York, N.Y' BAYRESOURCES SAN FRANCISCO Bair Island Eastof BayshoreFreeway(101),next to Redwood Shores- bkd watching and hiking. Under the protection of P.O.S.Tas of January 1997, this largest expanseof restorable wetland needspublic support and funds to completethe purchase' Bayfront Park Bayfront Expressway,Menlo Park - bird watching, hiking. Burlingame Shorebird Sanctuary BayshoreHighway, Burlingame -bird watching. Candlestick Point Gilman Ave., San Francisco (415) 822-9266 -brdwatching, fishing, hiking, picnicking. Coyote Creek Lagoon Fremont Blvd., South of Cushing Parkway, Fremont - bfud watching, fishing, hiking, picnicking, nafute center, boatlanding, restrooms' SAN FRANCISCO BAY RESOURCES Coyote Point Park Coyote Point Drive, Burlingame (650)573-2592- bird watching, fishing, hiking, picnicking, nature center,boatlanding, restrooms. Don Edwards San FranciscoBay National Wildlife Refuge Environment Education Center Grand Blvd., Alviso (408) 262-5513- bird watching, hiki.g picnicking, nature center, restrooms. Environmental Volunteers 3921East BayshoreRd., Palo Alto, CA 94303(650) 424-8035- natural science educationalprograms and field trips for children gradesK - 8. Golden Gate National RecreationArea Fort Baker, Marina, Fort Mason, Aquatic Park, San Francisco - bird watching, fishing, hiking, picnicking area,resfrooms. Marine ScienceInstitute 1200ChesapeakeDr., Redwood City, CA 94063-7142(650)364-2760- bay discovery education programs for children. Mountain View Shoreline Park Stierlin Road, Mountain View (650)903-6392- bird watching, hiking, picnicking. Oyster Point Park Oyster Point Blvd., South San Francisco- bird watching, fishing, hiking, picnicking, boat landing, restrooms. Palo Alto Baylands Park Embarcadero Road, Palo Alto (650) 329-2505- bird watching, fishing, hiking, picnicking,nafule center,boatlanding,restrooms. Palo Alto Junior Museum 1451Middlefield Rd., Palo Alto, CA 94301(650)329-2111-natural scienceeducation servicesfor Palo Alto area. Peninsula Conservation Center 3921.East Bayshore Rd., Palo Alto, CA 94303(650) 494-9301- environmental library. Port of Redwood City ChesapeakeDrive, Redwood City - bird watching, hiking. San FranciscoBay National Wildlife Refuge Visitor Center Marshlands Road, Fremont (510)792-4275 - bn d watching, fishing, hiking, picnicking, nature center,boatlanding, restrooms. page24 Bay Guide SAN FRANCISCOBAY RESOURCES San Mateo County Shoreline Trail San Mateo, FosterCity - bird watching, fishing, hiking, picnicking' Sierra Point Sierra Point, Brisbane-bfud watching, fishing, hiking, picnicking. Sunnyvale Baylands Park Sunnyvale - bird watching, hiking, picnicking, boatlanding, restrooms. Youth ScienceInstitute 16260Alum Rock Ave., San Jose,CA 95127(408)258-4322- scienceeducation programs for children of all ages. BIBLIOGRAPHY 1. An Introductionto theEcologyof SanFranciscoEstwry.1990, SaveSan FranciscoBay Association,Oakland, California 2. palo Alto BaylandsHandbook.7975znd edition, The Leagueof Women Voters of Palo Alto, Palo Alto, California SanFranciscoBny.7984, on theenuironmtntand resources.of 3. Tfu ChangingBay:reaiewm.aterials Califomia Francisco, San Bay Chapter, Francisco OceanicSod"ty"- San 5. BaylandsSiteGuide.1989,EnvironmentalVolunteers,Ltc., Palo Alto, Califomia guide.1990San FranciscoBay National WildliJe Refuge,U.S. 6. SaltMarsh Manual,an educator's Alviso, Califomia Fish and Wildlife Service, 3rd ed., San FranciscoBay Wildlife Society T. Conradson,Diane. ExploringOur Baylands.7995 8. Hunt, Murray. Salt marsh map, figure#3,199I, EnvironmentalVolunteers,Palo Alto, Califomia.