This week:

• Inland seas• Homework 2• Wednesday – UC Botanical Garden• Next Monday: Exam 2 includes:

– History of Conservation– Animal groups– Geology– Central Valley, Riparian– Inland Seas, Lakes, Rivers

Inland WatersInland Waters

Fresh Water a precious resource

Importance of Fresh Water

areas

Fresh Waters• Surface waters run off, down hill• All area that collects water forms a

water shed for a river, delta, bay• Source zone

– High oxygen levels, clear water– fast moving head waters, waterfalls

• Transition zone• Floodplain zone

– Muddy water– Low oxygen levels

River Zones

Our Watershed

• Drains to Carquinez Straits

Lakes - water collects in a catch depression

Lake type determine by how it formed:

• Glacial

• Tectonic

• Landslide

• Volcanic

• Fluviatile

• Shoreline

• Terminal or Closed basin

Glacial Lakes• Glacial action- Common in Sierras• Tarns (lakes) formed by glacier action

leaving low spots in bed rock-– Pater Noster- series of cirques (tarns with high

vertical back wall) down a mountain

• Moraine lakes- impeded by moraine.– May have a blue color due to suspended rock

particles– Common on east side of Sierras

• Kettles form as holes in the moraine field

Tarn

Cirque

Pater Noster

Kettle

Tectonic process – uplifting, and depressions in

dip-slip Faults• Graben (grave) lakes

– Lake Tahoe (1). Original lake formed between two blocks of stone as fault slipped down.

– Livermore Valley - gravels

Lake Tahoe

Volcanic Lakes• Lava flows blocks water flow • Common along faults, often form in

conjunction with tectonic (as in Tahoe)• Clear lake - Dammed by lava.

– Two arms fill in grabens.• Current form of Lake Tahoe (2)

– Was deepened by lava flow at Truckee end.• Caldera Lake forms when a volcano blows

off its summit and leaves the sunken caldera which fills with water.– Crater lake in Oregon, deepest in US.

• Small surface area restrict evaporation – stays full with winter rains/snow

Crater Lake

Landslide lakes-

• Rock, Mud flow traps flow, raises water level

• Mirror lake in Yosemite. Several on Kern River.

• Often short lived as water digs in new channel.

• Often form in narrow river canyons.• Caused by mudslides or

earthquakes.

Fluviatile - From in depression formed by flowing water

• Ox Bow lakes - cut off from main channel.

• River Dam lakes - Sediment flowing down a tributary blocks main channel. – Kings River sediment blocked flow

North up San Joaquin valley. – Tulare river flows south, formed lake

Tulare.

Shoreline -

• impounded by barriers of sand by wind and waves at River mouths.

• maybe seasonal

• Can break quickly- – a tourist drowned in San Lorenzo River -

at Santa Cruz, washed out to sea.– We’ll see a small lake at Salmon Creek

beach

Terminal or Closed basin• Watershed with no outlet

– Dependent on inflow vs. evaporation rates

• Mono Lake-Oldest lake in California– Hypersaline, accumulating solutes for

thousands of years– Tufa towers form under water in bubbles in

brine solution– One of most productive ecosystems– Water Diversion in Owens River

• Level dropped 46 feet since 1946.

– 1994 decision mandated rising lake 20 feet.

Mono Lake Currently at

6382.3 ft.Goal: 6391 ft.

in 2014

20th Century Low, January 1982 6,372 ft above sea level

Beginning of Diversions, 1941 6,417 ft above sea level

20th Century High, 1919 6,428 ft above sea level

Overflow Level, 100,000 years ago 7,200 ft above sea level

Aral Sea - disappearing• Rivers being diverted for agriculture

• From 4th to 8th largest lake

• (1960) 68,000 km2; (1998) 28,000

• Salinity increasing, salt blows onto fields

Created Lakes: Reservoirs

• All have an estimated life span until sediments fills them in.

• Block fish migrations, silt flow to flood plain

• Control floods• Clean Power source

Limnology: Study of lakes• Littoral Zones:

– near shore, sunlight – marsh, floating plants (macrophytes)– Lots of decomposers – marsh food chain

• Limnetic Zone– Open sunlight waters, – main photosynthetic (producers) zone

• Profundal Zone– Deep open water, too dark for photosynthesis

• Benthic Zone– Bottom of lake inhabited by decomposers, and

other animals adapted to cold, oxygen poor water: snails, worms, crayfish, catfish

Lake Ecosystem

Dissolved Oxygen (DO)

• Oxygen needed for cell activity• Low oxygen levels limit activity of

animals.– Can cause massive die offs

• BOD- is biological oxygen demand– caused by organic wastes in water

(pollution). – Decomposers use up oxygen in the

rapid growth.

• DO Sensitive to temperature, pH levels in water.

Slide 2

Fig. 19.2, p. 478

WaterQuality

Good 8-9

(BOD) Dissolve Oxygen (ppm) at 20?C

Slightlypolluted

Moderatelypolluted

Heavilypolluted

Gravelypolluted

6.7-8

4.5-6.7

Below 4.5

Below 4

Slide 3

Fig. 19.3, p. 479

Clean Zone DecompositionZone

Septic Zone Recovery Zone Clean Zone

Normal clean water organisms(Trout, perch, bass,

mayfly, stonefly)

Trash fish(carp, gar,Leeches)

Fish absent, fungi,Sludge worms,

bacteria(anaerobic)

Trash fish(carp, gar,Leeches)

Normal clean water organisms(Trout, perch, bass,

mayfly, stonefly)

8 ppm

Dissolved oxygen

Biological oxygendemand

Oxygen sag

2 ppm

8 ppm

Co

nce

ntr

atio

n

Typ

es o

fo

rgan

ism

s

Time of distance downstream

Direction of flow

Point of waste orheat discharge

Seasonal changes in Alpine lakes

• Water mixes in Fall and Spring, oxygen, nutrient levels uniform

• Summer warming stratifies lakes – Water floats over cooler, forming a thermocline– Lower water is nutrient rich – Lack oxygen– Upper warmer water may run out of nutrient for

photosynthesis

• Winter may have insulating ice layer, forming a stratification

Slide 19

Fig. 7.16, p. 167

Upper Warm water

Lower Cold water

ThermoclineSummer Fall overturn

22?20?

18?8?

6?5?

4?C

0?2?

4?4?

4?

4?C

Winter Spring overturn

4?4?

4?4?

4?

4?C

Dissolved O2 concentration High Medium Low

4?4?

4?4?

4?

4?C

Lake Succession• Lakes fill-in over time. Nearly all the

nutrients come from outside the lake. – e.g. Lake Yosemite filled valley after ice melted

• Oligotrophic few nutrients. – Clear, bluish water little algae – high dissolved oxygen– Few fish, e.g.. Trout (small gills, easy to get

oxygen)• Meso- intermediate • Eutrophic- more and higher nutrient levels

– Low oxygen levels. Green color• Senescent- filled in, becoming meadow

– Crane Flat in Yosemite

Oligotrophic Eutrophic

Age Young Old

Nutrients Poor Rich

Clarity Clear Cloudy

Color Blue Green to brown

Depth Deep ShallowTemperature Cold Warmer

D Oxygen High trough out Low, at surface

D solids Low High

Sediment Sparse, coarse Deep, muddy

Locality Mountains Valleys

Fish Trout Catfish

Oligotrophic

Eutrophic

Cultural Eutrophication: human influences cause lakes to become eutrophic due to pollution, erosion.

Stream / River types: (Indicated on topo maps)

• Permanent- year round• Intermittent - seasonal, winter /

spring flow, dry summer fall. • Interrupted- parts flow above ground,

other parts below (common in Southern California)

• Slough - slower moving side channel of larger creek, stream, river

Bends in the Rivers, Streams

• Coriolis affect causes water to flow in an arch on a flat plain, – to the right in the Northern hemisphere, – causes streams to meander, as water curves

until it reaches an uphill.– Can be seen in rivers in Central Valley

• As stream erodes the channel on its outside bend, it deposits new sediments on the inside. New soil is formed.– Heavy rocks only moved in great floods, rivers

carry mostly gravel, sand, silt, and clay. Clay moves the farthest.

• Meanders have a distinctive structure. On the bend of a river, the water rushes to the outside of a bend. This photograph shows the inside, known as a slip-off slope. This is a small area of deposition and creates a gentle slope.

Rivers transport erosion debris

• Deforestation adds to erosion, and sediment loads in rivers

• Add to near shore pollution, nutrient loads in oceans

Everglades

• Fifty miles (80 km) wide in places, one to three feet (0.3 to 0.9 meters) deep in the slough's center but only 6 inches (15 cm) deep elsewhere, it flowed south 100 feet (30 meters) per day

• Water diversion started killing off this vast marsh lands

• Largest restoration project ever attempted started in 1996.

• National Parks are not islands- they still can be influenced by development outside their boundaries.

Water Diversion in California

• “Water wars”– North- most of water– South most of the

population• Agriculture uses the

most• Cities cut back the most

in droughts• Population continues to

grow• Recycling water can

save millions of gallons

• Wildlife loose out down stream