Les passed by a cotton field and has some thoughts you may wish to know. Link.
San Francisco gets an Andy Goldsworthy sculpture. Link. (Stanford has the Bay Area's only other Goldsworthy that I know about. Link. Well, no, there's his project at the DeYoung, too.)
Behold the dramatic range of human facial expression: baby gets a bath. (And tell me what that thing is in the lower right-hand corner of the first picture.)
Annie's Annuals 20%-off mail order sale ends on Friday. Things I want: Campanula vidalii, Cussonia transvaalensis, Puya mirabilis.
Would you grow a purple tomato? I would.
Slime molds. Insects.
Showing posts with label ecology. Show all posts
Showing posts with label ecology. Show all posts
10/25/08
3/12/08
Ecology of San Francisco Bay, Pt 3
The Bay Model.
The U.S. Army Corps of Engineers built this concrete model of the San Francisco Bay-Delta system to test how possible land-use alterations might affect the Bay's hydrology. They also used it to model sediment flows, oil spills, et cetera.
The model was in service from 1957 until January 2000. Now Bay engineers use computers, and the Model is open to visitors.
In the 1940s an idea to dam and fill parts of the Bay put forth by "actor, theatrical producer, and schoolteacher" John Reber acquired widespread interest:
Constructed in two phases, starting in 1956, the Model consists of 286 slabs of concrete, each measuring 12-ft by 12-ft and weighing five-tons. The Model covers an area equivalent to two football fields.
The model fills with water and replicates a 24-hour tidal cycle every 14.4 minutes. (The water was turned off during my visit.) An hour of real life passes every 36 seconds in the model. Two-thirds of the San Francisco Bay-Delta is less than 18 feet deep. In order for the Model to hold measurable amounts of water in its shallowest extremities, the model uses altered horizontal and vertical scales.
The deepest part of the Bay (330 ft) is right under the Golden Gate Bridge, where the largest amount of water passes through the narrowest strait.
The copper tabs help to simulate friction between water and the Bay floor.
In the 19th century, gold miners diverted rivers to make water cannons that blasted away mountainsides. Downstream, the muddy debris raised rivers that flooded towns and farms, turned marshlands into uplands, and deposited deep layers of mud on the bottom of the Bay. Hydraulic mining was banned in 1884 by a federal court order.
An astonishing forty percent of California drains into San Francisco Bay; I dig this old-school model that shows the Sierra snowpack melting into rivers (which in real life are all dammed).
You can also see from this why the South Bay is the saltiest part of the Bay. All the freshwater flows in from the Delta and out through the Golden Gate, without much mixing. Freshwater inputs in the South Bay come mostly from treated wastewater.
Link to Ecology of San Francisco Bay Introduction and TOC.
The U.S. Army Corps of Engineers built this concrete model of the San Francisco Bay-Delta system to test how possible land-use alterations might affect the Bay's hydrology. They also used it to model sediment flows, oil spills, et cetera.
The model was in service from 1957 until January 2000. Now Bay engineers use computers, and the Model is open to visitors.
In the 1940s an idea to dam and fill parts of the Bay put forth by "actor, theatrical producer, and schoolteacher" John Reber acquired widespread interest:
Under the plan, which was known as the San Francisco Bay Project or the Reber Plan, the Sacramento River mouth from Suisun Bay would be channelized by dams and would feed two freshwater lakes within the bay, providing drinking water to the residents of the Bay Area. The barriers would support rail and highway traffic and would create two vast freshwater lakes, supplying irrigation water to farms. Between the lakes, Reber proposed the reclamation of 20,000 acres (81 km²) of land that would be crossed by a freshwater channel. West of the channel would be airports, a naval base, and a pair of locks comparable in size to those of the Panama Canal. Industrial plants would be developed on the east.Link.
In 1953 the U.S. Army Corps of Engineers recommended more detailed study of the plan and eventually constructed a hydraulic model of the Bay Area to test it. The barriers, which were the plan's essential element, failed to survive this critical study. The scrapping of the Reber Plan in the early 1960's was one sign, perhaps, of the end of an era of grandiose civil works projects aimed at totally restructuring a region's natural environment, and the birth of the environmental era.
Constructed in two phases, starting in 1956, the Model consists of 286 slabs of concrete, each measuring 12-ft by 12-ft and weighing five-tons. The Model covers an area equivalent to two football fields.
The model fills with water and replicates a 24-hour tidal cycle every 14.4 minutes. (The water was turned off during my visit.) An hour of real life passes every 36 seconds in the model. Two-thirds of the San Francisco Bay-Delta is less than 18 feet deep. In order for the Model to hold measurable amounts of water in its shallowest extremities, the model uses altered horizontal and vertical scales.
The deepest part of the Bay (330 ft) is right under the Golden Gate Bridge, where the largest amount of water passes through the narrowest strait.
The copper tabs help to simulate friction between water and the Bay floor.
In the 19th century, gold miners diverted rivers to make water cannons that blasted away mountainsides. Downstream, the muddy debris raised rivers that flooded towns and farms, turned marshlands into uplands, and deposited deep layers of mud on the bottom of the Bay. Hydraulic mining was banned in 1884 by a federal court order.
An astonishing forty percent of California drains into San Francisco Bay; I dig this old-school model that shows the Sierra snowpack melting into rivers (which in real life are all dammed).
You can also see from this why the South Bay is the saltiest part of the Bay. All the freshwater flows in from the Delta and out through the Golden Gate, without much mixing. Freshwater inputs in the South Bay come mostly from treated wastewater.
Link to Ecology of San Francisco Bay Introduction and TOC.
3/7/08
Ecology of San Francisco Bay, Part 2
Don Edwards San Francisco Bay National Wildlife Refuge.
This is a salt marsh habitat restoration project in south San Francisco Bay in the town of Newark just across the Dunbarton Bridge from Palo Alto. Salt marshes are very productive habitats from an ecological perspective. Most of California's salt marshes have been destroyed. In south San Francisco Bay, many salt marshes were converted to salt ponds to produce commercial-grade salt from the evaporation of salty Bay water. Though man-made, salt ponds attract and sustain their own wildlife ecologies. Learning how to balance the interests of both salt pond and salt marsh ecologies is an ongoing focus of restoration ecology.
I'd never been here before. I thought it would be interesting to see a salt marsh on my own before I go with the class.
The Bay marshes are on the other side of this hill. I see they've also done a lot of native plant restoration.
Flowers of Arbutus menziesii (Ericaceae)
Salvia spathacea and Ceanothus...'Julia Phelps'?
The Ceanothus buds go from plummy purple to rosy pink before the flowers open.
Salvia mellifera, right?
The salt ponds and marshes on the other side of the hill. That's a former hunting cabin, rather restored I think.
Clear biotic zonation where the pickleweed meets the dry upland.
Pickleweed (Salicornia sp., Chenopodiaceae). Chenopods have none of the symbioitic relationships with mycorrhizzal fungi that help other plants survive in adverseclimate situations growing conditions. Pickleweed as its own adaptations to living in briny waters.
Pickleweed migrates salt from roots to shoots and compartmentalizes the salt in extremity plant part. Then the plant scissions the salty extremity and lets it fall off.
Some bird sightings:
I think this is a dowitcher, possibly a winter?
The black-necked stilt, Himantopus mexicanus.
The Peterson Guide says, "A large, extremely thin wader; black above, white below. Note the grotesquely long red legs and needle-like bill. In flight, the black unpatterned wings contrast strikingly with the white tail, wing, and underparts.
Voice: A sharp yipping: kyip kyip kyip.
Well, I didn't hear any of that. But he took off and his legs were very long.
And then this dude jogged past me with his long, stilt-like legs. You can't make it up, folks.
I think the technical name for this one is "little brown bird".
Mallards, Anas platyrhynchos.
The silty clay dredged up to shore the levees was interesting in its own way too.
Lots of embedded oyster shells.
These might be identified in the plant key handout for the reserve. I'll look them up later.
Lots of Chlorogalum.
I've never seen it so profuse in a disturbed space like this.
This little lupine is starving for something. Maybe water?
Lots of small den-like structures in the marsh.
Time to go.
Introduction and TOC.
This is a salt marsh habitat restoration project in south San Francisco Bay in the town of Newark just across the Dunbarton Bridge from Palo Alto. Salt marshes are very productive habitats from an ecological perspective. Most of California's salt marshes have been destroyed. In south San Francisco Bay, many salt marshes were converted to salt ponds to produce commercial-grade salt from the evaporation of salty Bay water. Though man-made, salt ponds attract and sustain their own wildlife ecologies. Learning how to balance the interests of both salt pond and salt marsh ecologies is an ongoing focus of restoration ecology.
I'd never been here before. I thought it would be interesting to see a salt marsh on my own before I go with the class.
The Bay marshes are on the other side of this hill. I see they've also done a lot of native plant restoration.
Flowers of Arbutus menziesii (Ericaceae)
Salvia spathacea and Ceanothus...'Julia Phelps'?
The Ceanothus buds go from plummy purple to rosy pink before the flowers open.
Salvia mellifera, right?
The salt ponds and marshes on the other side of the hill. That's a former hunting cabin, rather restored I think.
Clear biotic zonation where the pickleweed meets the dry upland.
Pickleweed (Salicornia sp., Chenopodiaceae). Chenopods have none of the symbioitic relationships with mycorrhizzal fungi that help other plants survive in adverse
Pickleweed migrates salt from roots to shoots and compartmentalizes the salt in extremity plant part. Then the plant scissions the salty extremity and lets it fall off.
Some bird sightings:
I think this is a dowitcher, possibly a winter?
The black-necked stilt, Himantopus mexicanus.
The Peterson Guide says, "A large, extremely thin wader; black above, white below. Note the grotesquely long red legs and needle-like bill. In flight, the black unpatterned wings contrast strikingly with the white tail, wing, and underparts.
Voice: A sharp yipping: kyip kyip kyip.
Well, I didn't hear any of that. But he took off and his legs were very long.
And then this dude jogged past me with his long, stilt-like legs. You can't make it up, folks.
I think the technical name for this one is "little brown bird".
Mallards, Anas platyrhynchos.
The silty clay dredged up to shore the levees was interesting in its own way too.
Lots of embedded oyster shells.
These might be identified in the plant key handout for the reserve. I'll look them up later.
Lots of Chlorogalum.
I've never seen it so profuse in a disturbed space like this.
This little lupine is starving for something. Maybe water?
Lots of small den-like structures in the marsh.
Time to go.
Introduction and TOC.
Ecology of San Francisco Bay, Part 1
Notes and quotes on salt production in San Francisco Bay.
200M tons of salt is produced worldwide every year. North America produces more than one-quarter of it. The U.S. is the world's second largest salt producer, producing 46 million tons a year (China is number one, producing 48M tons--and climbing). Brines for use by chemical companies account for nearly half of this salt production. The remaining is "dry salt" produced by one of three basic technologies: solar evaporation of seawater or saline lake water, solution mining and vacuum pan evaporation and conventional deep-shaft (rock salt) mining. Link.
(Note: "Table salt is typical of the fine, granulated-evaporated salt produced in vacuum pan evaporators. Nearly all food grade salt in the United States is produced by vacuum pan evaporation of brine.” Link.
Sales of dry salt jumped 37.2% in 2007 to 31.7 million tons, according to the annual Salt Institute Statistical Report of US Salt Sales released in February, 2008. Salt industry revenues rose 11.9% to $1.68 billion, excluding transportation costs. Link.
***
From Save The Bay's Turning Salt into Environmental Gold [PDF]:
(Note: The world’s largest solar salt works in Guerrero Negro, in Baja California. Link, Link).
***
"In chemical terms, salt is the combination of a sodium ion with a chloride ion, making it one of the most basic molecules on earth. It's also one of the most plentiful: it has been estimated that salt deposits under the state of Kansas alone could supply the entire world's salt needs for the next 250,000 years." Link.
Seawater contains about 3.5% (by weight) dissolved minerals. Sodium chloride is 2.7% of seawater (w/w). The other 0.8% consists of calcium, magnesium and sulfate ions. As seawater evaporates, its volume decreases and the concentration of sodium chloride in the resulting brine increases. Thus, saltworks generally extract as sodium chloride a bit over 2% of the weight of the influent seawater. This means that solar saltworks are quite extensive in area.
The concentrating ponds often have distinct coloration, a pink or red, depending on the salt concentration and what species of plants and animals find it habitable. Link.
Salt pond colors reflect a complex interaction of plants, animals, and varying salinity.
From Save the Bay's Turning Salt into Environmental Gold [PDF]:
***
In 1924, the Leslie California Company began acquiring an empire in bay-side lands suitable for harvesting salt by buying up smaller companies or defunct operations: Plummer, Cyrstal, Turk Island, Arden Salt. Few other climates in the world afforded recovery of salt by solar evaporating of sea water--the cheapest and most efficient salt recovery method of all. But salt wasn’t the entire motive for the swift rise of tidal land sales and new incorporations. Sea water is rich in other chemicals: bromine, magnesium, chlorine, sodium, and potassium. The need for most of these chemicals had been non-existent before 1900, but during World War I, San Francisco Bay’s giant salt concentration ponds provided a source of chemicals useful in the manufacture of explosives. By 1925, a small chemical plant was in operation in Newark using bittern--waste water from salt concentration ponds--to manufacture explosives component magnesium chloride. They called themselves the California Chemical Company. Link.
Bittern ponds reach salinities of 447 parts per thousand--nearly 13 times more saline than seawater. Bittern’s high salinity and "ionic imbalance" is toxic to aquatic species. Once bittern is produced, few options exist for its disposal. Prior to 1970, bittern that was not sold was discharged into San Francisco Bay. By the early 1970s, the federal Clean Water Act and the state Porter-Cologne Water Quality Control Act prohibited bittern discharge in to the Bay. Thus began ongoing, long-term bittern storage onsite. While some bittern continues to be sold for use in dust suppressants and de-icers, much of the bittern produced since the 1970s is stored within the South Bay salt pond complex. Recent operational changes have reduced bittern production, but the backlog of stored bittern remains.
Bittern disposal is an important consideration when assessing the feasibility of salt pond restoration. As part of its operations, Cargill conducts numerous maintenance activities in the Bay salt pond complex, but levee maintenance is the most common. This is required due to erosion, subsidence, and soil compaction.
Incidentally: "Kosher salt is characterized by its big crystals with large surface areas and its lack of additives, such as iodine. This size and shape allows it to absorb more moisture than other forms of salt, and this makes kosher salt excellent for curing meats."
Introduction and TOC.
200M tons of salt is produced worldwide every year. North America produces more than one-quarter of it. The U.S. is the world's second largest salt producer, producing 46 million tons a year (China is number one, producing 48M tons--and climbing). Brines for use by chemical companies account for nearly half of this salt production. The remaining is "dry salt" produced by one of three basic technologies: solar evaporation of seawater or saline lake water, solution mining and vacuum pan evaporation and conventional deep-shaft (rock salt) mining. Link.
(Note: "Table salt is typical of the fine, granulated-evaporated salt produced in vacuum pan evaporators. Nearly all food grade salt in the United States is produced by vacuum pan evaporation of brine.” Link.
Sales of dry salt jumped 37.2% in 2007 to 31.7 million tons, according to the annual Salt Institute Statistical Report of US Salt Sales released in February, 2008. Salt industry revenues rose 11.9% to $1.68 billion, excluding transportation costs. Link.
***
From Save The Bay's Turning Salt into Environmental Gold [PDF]:
"Salt production in the San Francisco Bay began during the 1860s. The current network of South Bay salt production ponds has been operated for approximately 50 years, with Cargill acquiring the ponds from Leslie Salt in the late-1980s. Annually, Cargill currently produces 650,000 tons of salt per year on a total of 26,190-acre solar evaporation pond complexes using approximately 40 million tons of Bay water."Cargill's total potential salt production capacity in the South Bay is over 1 million tons.
(Note: The world’s largest solar salt works in Guerrero Negro, in Baja California. Link, Link).
***
"In chemical terms, salt is the combination of a sodium ion with a chloride ion, making it one of the most basic molecules on earth. It's also one of the most plentiful: it has been estimated that salt deposits under the state of Kansas alone could supply the entire world's salt needs for the next 250,000 years." Link.
Seawater contains about 3.5% (by weight) dissolved minerals. Sodium chloride is 2.7% of seawater (w/w). The other 0.8% consists of calcium, magnesium and sulfate ions. As seawater evaporates, its volume decreases and the concentration of sodium chloride in the resulting brine increases. Thus, saltworks generally extract as sodium chloride a bit over 2% of the weight of the influent seawater. This means that solar saltworks are quite extensive in area.
The concentrating ponds often have distinct coloration, a pink or red, depending on the salt concentration and what species of plants and animals find it habitable. Link.
Salt pond colors reflect a complex interaction of plants, animals, and varying salinity.
• Low to mid-salinity ponds: Green algae creates the color.***
• Moderate salinity ponds: Dunaliella algae proliferates and turns the ponds a lighter shade of green.
• High salinity ponds: High salt concentrations cause the Dunaliella to produce a red pigment. Halophilic bacteria contribute to the red and purplish-red hues. Millions of tiny brine shrimp in mid-salinity ponds add an orange cast.
• In choppy conditions, the colors appear murkier. Heavy rain can even turn the water clear.
From Save the Bay's Turning Salt into Environmental Gold [PDF]:
Solar salt production begins when Bay water flows into intake ponds via pumps or tide gates. Bay water is less salty than seawater owing to dilution by freshwater from the Sacramento and San Joaquin Rivers, local streams, creeks, and wastewater treatment discharges. This is especially true in winter and early spring when rain and melting snow increase freshwater flows into the Bay. Cargill normally takes Bay water into its system during the dry season when the Bay's salinity is highest--beginning in April or May and continuing in to fall."It takes five years for the sun and wind to evaporate Bay water and produce salt. During this time, the water is moved through a series of ponds. Each successive pond is saltier than the last and each supports different kinds of organisms." (Visitors Center educational sign at the Don Edwards San Francisco Bay National Wildlife Refuge.)
In Stage 1 ponds, water volume is reduced by 70 percent, with salinity increasing accordingly. In Stage 2 ponds, salinity increases further and gypsum (calcium sulfate) begins to precipitate. The final Stage 2 evaporator pond, called the "pickle pond", distributes concentrated brine to the crystallizer ponds. By the time pickle leaves the pickle pond each spring, 95 percent of the intake pond's original water has evaporated. The pickle water undergoes its final evaporation in the crystallizer ponds. Sodium chloride precipitates at a rate of approximately 40 tons per acre. By September, the salt bed is five to eight inches deep. Salt harvesting begins in October and continues 24 hours per day until the end of December.
***
In 1924, the Leslie California Company began acquiring an empire in bay-side lands suitable for harvesting salt by buying up smaller companies or defunct operations: Plummer, Cyrstal, Turk Island, Arden Salt. Few other climates in the world afforded recovery of salt by solar evaporating of sea water--the cheapest and most efficient salt recovery method of all. But salt wasn’t the entire motive for the swift rise of tidal land sales and new incorporations. Sea water is rich in other chemicals: bromine, magnesium, chlorine, sodium, and potassium. The need for most of these chemicals had been non-existent before 1900, but during World War I, San Francisco Bay’s giant salt concentration ponds provided a source of chemicals useful in the manufacture of explosives. By 1925, a small chemical plant was in operation in Newark using bittern--waste water from salt concentration ponds--to manufacture explosives component magnesium chloride. They called themselves the California Chemical Company. Link.
Bittern ponds reach salinities of 447 parts per thousand--nearly 13 times more saline than seawater. Bittern’s high salinity and "ionic imbalance" is toxic to aquatic species. Once bittern is produced, few options exist for its disposal. Prior to 1970, bittern that was not sold was discharged into San Francisco Bay. By the early 1970s, the federal Clean Water Act and the state Porter-Cologne Water Quality Control Act prohibited bittern discharge in to the Bay. Thus began ongoing, long-term bittern storage onsite. While some bittern continues to be sold for use in dust suppressants and de-icers, much of the bittern produced since the 1970s is stored within the South Bay salt pond complex. Recent operational changes have reduced bittern production, but the backlog of stored bittern remains.
Bittern disposal is an important consideration when assessing the feasibility of salt pond restoration. As part of its operations, Cargill conducts numerous maintenance activities in the Bay salt pond complex, but levee maintenance is the most common. This is required due to erosion, subsidence, and soil compaction.
Incidentally: "Kosher salt is characterized by its big crystals with large surface areas and its lack of additives, such as iodine. This size and shape allows it to absorb more moisture than other forms of salt, and this makes kosher salt excellent for curing meats."
Introduction and TOC.
Ecology of San Francisco Bay, Introduction and TOC
I'm taking a two-day ecology class this weekend through the City College of San Francisco. The topic is San Francisco Bay. We're going to visit the Bay Model, Bothin Marsh Open Space Preserve, China Camp State Park, Heron's Head Park [formerly Pier 98], Bayfront Park, and the Palo Alto Baylands Park.
I expect to download a lot of information here in the next few days... feel free to tag along.
Or not...
The class starts tomorrow, but I have a few things to post today:
Part One, I had to write a short paper about a Bay topic, and I picked "Salt production in the Bay (technique and history)". That paper (mostly quotes and links) is here.
Part Two, I paid a visit yesterday to the Don Edwards San Francisco Bay National Wildlife Refuge (link, link)--a salt pond restoration site that we will not be visiting during my weekend ecology course, but that I have always wanted to see. I took some pictures and posted them here.
Part 3, San Francisco Bay-Delta Model.
Also, I want to specifically link to this curious group blog Hidden Ecologies, administered by various faculty at UC Berkeley. I found this while researching my paper on salt production in the Bay.
"Our project looks at places -- starting with several transitional geographies along San Francisco Bay -- in ways that juxtapose scales, collect different points of view, and encourage the sharing of ideas."
I especially enjoyed this post by architecture professor Charles Benton on aerial kite photography--that is, taking pictures from your camera while it's tied to a flying kite.
I expect to download a lot of information here in the next few days... feel free to tag along.
Or not...
The class starts tomorrow, but I have a few things to post today:
Part One, I had to write a short paper about a Bay topic, and I picked "Salt production in the Bay (technique and history)". That paper (mostly quotes and links) is here.
Part Two, I paid a visit yesterday to the Don Edwards San Francisco Bay National Wildlife Refuge (link, link)--a salt pond restoration site that we will not be visiting during my weekend ecology course, but that I have always wanted to see. I took some pictures and posted them here.
Part 3, San Francisco Bay-Delta Model.
Also, I want to specifically link to this curious group blog Hidden Ecologies, administered by various faculty at UC Berkeley. I found this while researching my paper on salt production in the Bay.
"Our project looks at places -- starting with several transitional geographies along San Francisco Bay -- in ways that juxtapose scales, collect different points of view, and encourage the sharing of ideas."
I especially enjoyed this post by architecture professor Charles Benton on aerial kite photography--that is, taking pictures from your camera while it's tied to a flying kite.
"Given a chance I suspect that most of us would slip our earthly bonds and see the world from new heights. An aerial view offers a fresh perspective of familiar landscapes and in doing so challenges our spatial sensibilities, our grasp of relationships. This playful talk will chronicle ten years of aerial photography from kite-lofted cameras. Examples will be shown from California’s wetlands including the South San Francisco Bay Salt Ponds, Herons Head Park, and the Berkeley/Albany Codornices Creek restoration project. Along the way Professor Benton will touch on the history of early aerial photography as well as methods and motivations for using kites as a photographic platform in the current day. Simultaneously an art form and a remote sensing exercise Benton’s low-level approach yields photographs that can be beautiful, useful, or both."
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