Notes Aquatic Ecology [Autosaved]

Aquatic Ecology Notes



_11/16

LT: I can explain the

properties that make

water unique, and why

they are important to

ecosystems.

Properties of Water linked

to Hydrogen Bonds

 _{The strong forces of attraction}

Heat Capacity

 _{Water changes temp very slowly}

because it can store heat

 _{This protects living organisms from the}

shock of abrupt temperature changes

 _{The temperature at which water turns}

to vapor

Heat of Vaporization

Universal Solvent

 _{Water can dissolve a wide} variety of compounds

 _{This means it can easily} become polluted by water-soluble wastes

 _{Ice has a lower density than} liquid water. Thus…

 _{Ice floats on water}

Importance

 _{Leonardo da Vinci said,}

“ Water is the driver of nature.”

 _{Without water, the other}

nutrient cycles would not exist in their present forms, and

current forms of life on earth could not exist

 _{Water keeps us alive, moderates}

climate, sculpts the land, removes and dilutes wastes and pollutants, and moves continually through the hydrologic cycle

 _{Less than 1% of the earth’ s water}

supply is available to us as liquid freshwater

 _{Some precipitation infiltrates the ground} and is stored in soil and rock

(groundwater)

 _{Surface water does not sink into the} ground or evaporate into the air;

instead, it runs off (surface runof) into bodies of water

 _{The land from which the surface water}

drains into a body of water is called its

watershed or drainage basin Comparison of population sizes and shares of the _{world’s freshwater among the continents.}

Water’s Importance,

Availability, & Renewal

Water’ s Importance,

Availability, & Renewal

 _{We currently use more than half of the world’ s}

reliable runoff of surface water and could be using 70-90% by 2025

 _{About 70% of the water we withdraw from}

rivers, lakes, and aquifers is not returned to these sources

 _{Distribution of Water Use}

 _{70%—Irrigation}

 _{20%—Industries (for coolant)}

 _{10%—Residences (sewage is the largest} user of water within domestic use)

Surface Water

 _{Streams, rivers, and lakes}

 _{Source –}

 _{Precipitation}

 _{Watershed –}

 _{EX: small streams}  larger streams  rivers  sea

 _{Aquifers – porous rock w/ water flowing through}

 _{Water Table – the level of earth’ s land crust to which}

the aquifer is filled

 _{Cone of depression occurs when the water table is}

lowered around a well

 _{Renewability – the circulation rate of groundwater is}

slow (300 to 4,600 years)

Precipitation Evaporation and transpiration Evaporation Confined Recharge Area Runoff Flowing artesian well Recharge Recharge Unconfined Unconfined Aquifer Aquifer Stream Well requiring a pump Infiltration Water table Lake Infiltration Unconfined aquifer Confined aquifer

Confining impermeable rock layer

Confining impermeable rock layer

Less permeable

Less permeable

material such as clay

Salinity



_{The saltiness of water.}

Organisms Categorized into

Broad Aquatic Zones

What Kinds of Organisms

Live in Aquatic Life Zones?

 _{Aquatic systems contain floating, drifting, swimming,}

bottom-dwelling, and decomposing organisms

 _{Plankton: important group of weakly swimming, free-floating biota}  _{Phytoplankton (plant)}

 _{Zooplankton (animal)}

 _{Ultraplankton (photosynthetic bacteria)}  _{Nekton: swimmers}

 _{Benthos: bottom dwellers}

Phytoplankton

 _{Description –}

small drifting plants

 _{Niche –}

they are producers that support most aquatic food chains

 _{Example –}

Zooplankton

 _{Description –}

small animal plankton that feeds on phytoplankton or other zooplankton

 _{Niche –}

food stock for larger consumers

 _{Example –}

Nekton

 _{Description –}

larger, strong-swimming consumers

 _{Niche –}

higher level consumers in the aquatic ecosystem

 _{Example –}

Benthos

 _{Description –}

bottom-dwelling creatures

 _{Niche –}

primary consumers, decomposers

 _{Example –}

11/20/17 Topic:

Aquatic Ecosystems



_{LT: I will be able}

to describe the

differences

between lentic

and lotic

ecosystems and

compare their

critical factors.

Freshwater

Ecosystems

Freshwater Life

Zones

 _{Freshwater life zones}

include:

 Standing (lentic) water

 Lakes

 Ponds

 Inland wetlands

 Flowing (lotic) systems

 Streams

Flowing Water

Ecosystems

conditions in each zone, a river is a system of different ecosystems

ECOLOGICAL SERVICES

• Deliver nutrients to the sea to help sustain coastal fisheries

• Deposit silt that maintains deltas

• Purify water

• Renew & renourish wetlands

• Provide habitats for wildlife

Freshwater Streams and Rivers:

From Mountains to Oceans

 _{Water flowing from mountains to the sea creates}

Headwater Stream

Characteristics

 _{A narrow zone of cold, clear water that}

rushes over waterfalls and rapids

 _{Large amounts of oxygen are present}  _{Fish are also present (EX: trout)}

Downstream

Characteristics

 _{Warmer temperatures}  _{Slower-moving water}  _{Less oxygen}

Standing Water

Ecosystems

Life in Layers

 _{Life in most aquatic systems is found in surface,}

middle, and bottom layers

 _{Temperature, access to sunlight for}

photosynthesis, dissolved oxygen content, nutrient availability changes with depth

 _{Euphotic zone (upper layer in deep water habitats):} sunlight can penetrate

Lakes: Water-Filled

Depressions

 _{Lakes are large natural bodies of standing freshwater formed from}

precipitation, runoff, and groundwater seepage consisting of:

 Littoral zone: near shore, shallow, with rooted plants

 Limnetic zone: open, offshore area, sunlit

 Profundal zone:

deep, open water, too dark for photosynthesis

 Benthic zone: bottom of lake, nourished by dead matter

LOTIC WATER SYSTEM—Name and describe the

zones.

LENTIC WATER SYSTEMS—Name and describe

the zones.

11/21/17 Topic:

Freshwater Wetlands



_{LT: I will be able to}

compare and

contrast between

wetland

ecosystems by

comparing their

vegetation and

critical factors.

Thermal

Stratification

a change in the temperature at different depths in the lake; due to the change in water's density with temperature

Lakes:

Thermal Stratification

 _{In temperate regions, lakes will become}

stratified into temperature layers

 _{During the fall and spring, the lake equalizes in}

temperature allowing for an overturn

 Oxygen is brought from the surface to the lake

bottom and nutrients from the bottom are brought to the top

The middle layer that acts as a barrier to the transfer of

Freshwate

r Wetlands

Freshwater Inland Wetlands:

Vital

Sponges

 _{Absorb and store excess water}

from storms

 _{Filter and degrade pollutants}  _{Reduce flooding and erosion by}

absorbing overflows

 _{Help replenish stream flows}

during dry periods

 _{Help recharge ground aquifers}  _{Provide economic resources and}

recreation

 _{Provide a variety of wildlife}

Marshes

_{An area temporarily flooded}

_{Often silty land beside a river or lake} _{Grass-like plants}

 _{A lowland region}

permanently

covered with water

 _{Woody plants}

Hardwood Bottomland Forest

 _{An area down by a}

river or stream where lots of hardwoods, like oaks, grow

 _{Occasionally flooded}

Prairie Potholes

 _{Depressions that hold}

water out on the

prairie, especially up north in Canada

Peat Moss Bog

 _{A wet area that over time fills}

in (the last stage of

succession is peat moss)

 _{Can be very deep}

Preserved “ Bog people”

 _{Placed in bogs}

 _{Peat moss collects salts, acidic}

water destroying bacteria in body

Connection to Congress

_{Developers and farmers want}

Congress to revise the definition of wetlands

 _{This would make 60-75% of all}

wetlands unavailable for protection

 _{The Audubon Society estimates that}

wetlands provide water quality protection worth $1.6 billion per

year, and they say if that wetlands are destroyed, the U.S. would spend $7.7 billion to $31 billion per year in additional flood-control costs

Estuaries

 _{When we dam rivers, less goes to the ocean.}

This means the brackish water becomes more salty

a partially enclosed area of coastal water where sea water mixes with freshwater

Salt Marshes

 _{Ground here is saturated with}

water

 _{Little oxygen, so decay is slow}

 _{Has a surface inlet and}

outlet

 _{Contains many invertebrates}

 _{Breeding ground for many ocean}

animals (EX: crabs and shellfish)

Mangrove Forests

 _{Along warm, tropical coasts}

where there is too much silt for coral reefs to grow

 _{Dominated by salt-tolerant}

trees called mangroves (55 different species exist)

 _{Helps to protect the}

coastline from erosion

 _{Provides a breeding nursery}

for some 2000 species of fish, invertebrates, and plants

Importance of Estuaries

 _{Just one acre of estuary provides}

$75,000 worth of free waste treatment and has a value of about $83,000 when recreation and fish for food are included

 _{Prime farmland has a top value of}

$7,000 per acre and an annual

production value of approximately $8,000

11/27/17



_{Topic: Degradation and Case}

Studies



_{LT: I can explain the process of}

Natural Capital Degradation

,

and compare the various case

studies to explain humans effect

on natural water sources.

Coliform Bacteria

 _{The W.H.O. (World Health Organization)}

recommends

 _{Zero colonies of coliform bacteria per} 100mL of drinking water

 _{200 colonies per 100mL of swimming} water

 _{The average human excretes 2 billion}

organisms per day

 _{See how easily untreated sewage can} contaminate water?

Oxygen released by vegetation Diverse Diverse ecological ecological habitat habitat Evapotranspiration

Trees reduce soil erosion from heavy rain and wind

Agricultural land Steady river flow Leaf litter improves soil fertility Tree roots stabilize soil and aid water flow

Vegetation releases water slowly and reduces flooding

Forested

Hillside

Upland

Tree plantation Roads Roads destabilize destabilize hillsides hillsides Evapotranspiration decreases Ranching accelerates soil erosion by water and wind

Winds remove fragile topsoil

Agricultural land is flooded and silted up

Gullies and

Gullies and

landslides

landslides

Heavy rain leaches nutrients from soil and erodes topsoil

Silt from erosion blocks rivers and reservoirs and causes flooding downstream

Rapid runoff causes flooding

Surface Water Problems

 _{The polluted Mississippi River}

(non-source point pollution) has too

much phosphorus

 _{In the Eerie Canal, which connects the}

Atlantic ocean to the Great Lakes, lampreys came in and depleted the fish

 _{The zebra mollusk is also a problem in the}

Core Case Study:

A Biological Roller Coaster Ride

in Lake Victoria

 _{Lake Victoria has lost their endemic (commonly found or native) fish}

species to large introduced predatory fish

 _{Reasons for Lake Victoria’ s loss of biodiversity:}

 _{Introduction of Nile perch}

 _{Lake experienced algal blooms from nutrient runoff}

 _{Invasion of water hyacinth has blocked sunlight and deprived oxygen}  _{Nile perch is in decline because it has eaten its own food supply}

Lake Baikal

 _{Deepest lake in the world}

 _{Maximum depth of 1,632m}

 _{One of the clearest and purest bodies of water (can see}

approximately 40 meters down)

 _{It’s becoming more popular to visit though…}

 _{300 streams and rivers flow into Lake Baikal; however there is only}

one outlet, the Angara

Effects of Plant Nutrients on Lakes:

Too Much of a Good Thing

 Plant nutrients from a lake’ s environment affect the types and numbers of organisms it can support

 Oligotrophic (poorly nourished) lake—usually a newly formed lake with small supply of plant nutrient input

 Eutrophic (well nourished) lake—Over time, sediment, organic material, and inorganic nutrients wash into lakes causing excessive plant growth

 Cultural eutrophication—Human inputs of nutrients accelerate the eutrophication process

 Brevetoxins can be produced

Hypoxic = low oxygen Anoxic = no oxygen

Perkinsus marinus (a protist

pathogen) infects oys

ters when DO is low.

Problems with Groundwater

 _Pollution

 _Salinity

 _{Over draining}

groundwater

 Sinkholes (aka

subsidence) form when the roof of an

underground cavern collapses after being drained of groundwater

11/28/17 Aquifer and Dam

case studies



_{LT: I will be able to describe}

the positive and negative

effect dams have on

ecosystems, as well as the

location and withdraw rates

of the worlds largest aquifer.

Groundwater Depletion:

A Growing Problem

 _{The Ogallala, the world’ s largest}

aquifer, is most of the red area in the center (Midwest)



Areas of

Areas of

greatest aquifer

greatest aquifer

depletion from

depletion from

groundwater

groundwater

overdraft in the

overdraft in the

continental U.S.

Ogallala Aquifer

 _{This is the world’ s largest known aquifer}

 _{Fuels agricultural regions in the U.S. (extends}

from South Dakota to Texas)

 _{Essentially a non-renewable aquifer from the}

last ice age with an extremely slow recharge rate

 _{In some cases, water is pumped out 8-10}

times faster than it is renewed

 _{Supplies about 1/3 of the groundwater}

used in America

 _{Northern states will still have ample supplies,}

but water is getting thin for the south

 Estimated that ¼ of the aquifer will be depleted by 2020

Dams and Reservoirs

 _Description:

A dammed stream that can capture and store water from rain and melted snow

 _Benefits:

 Hydroelectric power (cheap)

 Provides water to towns

 Recreation

 Year around irrigation

 Controls floods downstream

 _Problems:

 Reduces downstream flow and prevents water and sediment from reaching the sea, devastating fish life

 Reduces biodiversity and disrupts ecosystems

Powerlines

Reservoir

Dam

Powerhouse Intake

Provides water for year-round irrigation of cropland Flooded land destroys forests or cropland and displaces people

Large losses of water through evaporation Provides water for drinking _Downstream cropland and estuaries are deprived of nutrient-rich silt Reservoir is useful for recreation and fishing Risk of failure and devastating downstream flooding Can produce cheap electricity (hydropower) Downstream flooding is

reduced Migration and _{spawning of}

some fish are disrupted

FACTS

 45,000 large dams (higher than 15m or 50ft)

 Store 14% of world’s runoff

 Provide water for about ½ of irrigated crops

 Supply more than ½ the electricity used by 65 countries

Colorado River Basin

 _{Flows through 7 states and}

to the gulf of California

 Includes some of the driest lands in the US

 Only has a modest flow of water

 Contains 14 major dams and reservoirs, and canals

 Provides electricity from hydroelectric plants for 30 million people (1/10th of the U.S. population)

 _{Gets most of its water from}

Rocky Mountain snowmelt

 _{Now it rarely flows all the}

way to California

 _{What does this mean?}

Problems to come?

Hoover Dam Glenn Canyon Dam

11/29/17 Case Studies

Continued

Case Study:

China’ s Three Gorges Dam

 _{Extremely debated issue as to whether the advantages}

outweigh the disadvantages of the world’ s largest dam

 The dam is 2 kilometers (1.2 miles) deep

 Cost over $37 billion (1994 – 2006 ish)

 Produce an electric output of 22 large coal-burning or nuclear power plants (would fuel a city 10 times as large as LA)

 Holds back the Yangtze River’ s floodwaters (killed 500,000 in the past 100 years—4,000 were in 1998 alone)

 1998 flood caused an estimated damage equal to the cost of the dam

 Enables cargo-carrying ships to travel into China’ s interior

 The 600 km long reservoir has flooded over 1,000 cities and villages, thousands of archaeological sites, and has displaced approximately 1.4 million people

 Large dam means a large build up of sediment

 Prevents farming regions below the dam from receiving nutrient rich deposits

Three gorges dam

 _{The Three Gorges Dam is a hydroelectric gravity}

dam that spans the Yangtze River

 _{At full power, Three Gorges reduces coal}

consumption by 31 million tons per year, avoiding 100 million tons of greenhouse gas emissions,

70bmillions of tons of dust, one million tons of sulfur dioxide, 370,000 tonnes of nitric oxide, 10,000 tons of carbon monoxide, and a significant amount of mercury

 _{Destroyed 50% of forests and wetlands in the area}  _{57% of species in the area are endangered or at risk.}

Dam Removal

 _{Some dams are being removed for}

ecological reasons and because they have outlived their usefulness.

 _{In 1998, the U.S. Army Corps of Engineers}

announced that it would no longer build large dams and diversion projects in the U.S.

 _{The Federal Energy Regulatory Commission has}

approved the removal of nearly 500 dams.

 _{Removing dams can reestablish ecosystems, but}

can also re-release toxicants (a poison

Impact of a Flood…

 _{Flooding on one of Australia’ s riverbanks}

caused this phenomena on nearby local farmland….

Mono Lake (California)

 _{Diverted water from inlets, caused salt}

concentration to build in Mono Lake

 _{A terminal lake with no outlet}

 _{Full of carbonates, chlorides, sulfates,}

The Aral Sea Disaster

 Soviets begin diverting water from the Aral Sea and its 2 feeder rivers to irrigate cotton and wheat crops transforming it from 1of the 4 largest lakes to an “ environmental disaster”

 _{About 85% of the}

wetlands eliminated & roughly 50% of the local bird & mammal species have disappeared

 Used to supply 1/6th of

Soviet Union’s catch

 _{Since 1961, the sea’s}

salinity has tripled

 _{Dust storms plagued}

residents

 Respiratory illness & cancer are extremely prevalent in the region

2008

2008

2005 effort to restore the water has started to help restore the water supply

Case Study:

Restoring the FL Everglades

 _{The world’s largest ecological}

restoration project involves trying to undo damage inflicted by human activities

 _{90% of park’ s wading birds have vanished}  _{Other vertebrate populations down 75-95%}  _{Large volumes of water that once flowed}

through the park have been diverted for crops and cities

 _{Runoff has caused noxious (or harmful) algal}

blooms

11/30/17

_{Topic: Fishing}

_{LT: I can compare}

levels of efficacy and bycatch in

multiple currently used methods of fishing to

diferentiate between them.

Decline in Aquatic Species:

Overfishing

 _{The major decline in the worldwide catch of}

fish since 1990 is because of overfishing

 _{70-90% of the world’ s commercially valuable}

marine fish species are overfished or fished near their sustainable limits

 Big fish are becoming scarce

 Smaller fish are next

 We throw away a large percentage of the fish we catch

 _{Magnuson-Stevens Fishery Conservation and}

Management Act (1976, 2006)  Sets annual catch limits

 _{One of the earliest forms of large-scale fishing is}

pole fishing, where a line is attached to a baited hook, which can catch and pull in the fish.

 Of all the fishing methods, pole fishing has the lowest rate of

bycatch; species of fish that are unwanted and accidentally caught.

Pole Fishing

Pole fishing in the Maldives. Photo by Greenpeace.

_{As the world population grew, so}

did the demand for seafood.

_{15% of the world uses seafood}

as a primary source of protein.

_{Other methods}

began to take

the place of pole fishing to meet the demand.

 _{Longline fishing is a commercial fishing}

technique where baited hooks are attached to a single, long fishing line that trails behind a ship.

_{Compared to pole} fishing, longline

fishing has a much higher rate of

bycatch.

_{Sea birds are highly} vulnerable during setting of the line. _{Sea turtles, sharks,}

and other fish are also accidentally caught.

 _{The fastest and most efficient way to catch fish} is by trawling, where a large net is dragged

behind a ship.

 _{If the net actually drags along the bottom, it is}

called bottom trawling.

 _{Trawling has the highest rates of bycatch, since any species}

 _{Bottom-trawling has the added side effect of}

damaging any habitat at the bottom of the sea floor, such as coral reefs.

 _{The majority of the world’s fisheries are at their} maximum sustainable yield.

 _{This is the maximum that can be harvested without}

diminishing the population for future years.

 _{Overexploited fisheries are being harvested at} unsustainable levels.

 _{Over time, these can}

become depleted fisheries with stocks so low that fishing cannot be supported.

Fish farming in cage Trawler fishing Spotter airplane Sonar Trawl flap Trawl lines Purse-seine (or purse-dragnet) fishing Trawl bag Fish school Drift-net fishing Long line fishing Lines with hooks Fish caught by gills Deep sea aquaculture cage Float Buoy Used to catch tuna, dolphins are a bycatch

Human Impacts on Aquatic

Biodiversity

Area of ocean before and after a trawler net, acting like a giant plow, scraped it

12/4 Aquaculture

LT - I can compare the pros

and cons of wild caught

 _{As the limits of wild seafood harvesting have} become increasingly clear, industries are now beginning use aquaculture; the process of

farming aquatic organisms.

 _{The farming of saltwater organisms is} called mariculture.

 _{Most mariculture operations work by} taking eggs or immature fish and

raising them in long, rectangular nets called fish pens.

 _{Feed and other}

supplements are added to the top of the pen.  _{Wastes drop out the}

bottom of the pen to the sea floor.

 _{These operations are}

vulnerable to many of the

same issues as large animal farms, including antibiotic

overuse and manure.

8 9

 _{Fish farming can be combined with} hydroponics to create aquaponics.

 _{Waste water from fish farming is circulated}

through plants, which absorb the waste as nutrients and clean the water.

9 0

 _{Any fish labeled as farmed was raised in a} mariculture or aquaponics facility.

 _{Wild caught fish is just that – it was caught} from a body of water.

9 1

 _{MSC Certification is a label attached to any}

seafood that follows sustainable fishing practices, as established the Marine Stewardship Council.

9 2

Catching and Raising More

Fish and Shellfish

 Government subsidies given to the fishing industry are a major cause of overfishing

 Global fishing industry spends about $25 billion/year more than its catch is worth

 Without subsidies many fleets would have to go out of business

 Subsidies allow excess fishing with some keeping their jobs longer with making less money

 Fish farming is world’ s fastest growing type of food production

 Fish ranching involves holding anadromous species (species that live in saltwater and breed in freshwater)

 Fish are held for the first few years, released, and then harvested when they return to spawn

Water Management

Changing Aquatic Habitats & Declining Aquatic Life Creating More Freshwater & Conserving What We Have

H

O & Population Growth

 _{As population continues to grow,}

water problems increase:

 _{Over-drawing fresh water}  _Pollution

 _{Over-building so water can’ t seep}

Methods of “ Making”

More Freshwater:

Desalinization

 Description: Removing salt from salt H₂O

 _{Benefits: Provides freshwater}  _Problems:

 _{What do we do with the salt?}  _{Uses lots of energy}

 _{Costs 3-5x’ s as much as drawing freshwater}

 _{Processes for removing salt}

 _{Distillation: heating saltwater until it evaporates,}

leaves behind salt in solid form (brine)

 _{Reverse osmosis: uses high pressure to force}

Seeding clouds with tiny particles of chemicals to increase rainfall

 _{Silver Iodide}  Dry Ice

Towing icebergs or huge bags filled with freshwater to dry coastal areas

 Problems?

Technology not available

_{Costs too high}

_{Raise temperatures around the earth}

Other Methods of “ Making”

More Freshwater

Conservation: Increasing

Supplies by Wasting Less Water

 _{Sixty percent of the world’ s irrigation water} is currently wasted, but improved irrigation techniques could cut this waste to 5-20%  _{Center-pivot—low pressure sprinklers,}

sprays water directly onto crop

 _{80% of water reaches crop}

 _{Has reduced depletion of Ogallala aquifer}

Center pivot Center pivot Drip irrigation Drip irrigation Gravity flow Gravity flow

(efficiency 60% and 80% with surge

valves)

Above- or

below-ground pipes or tubes deliver water to

individual plant roots. Water usually comes from

an aqueduct system or a nearby river.

(efficiency 90–95%)

(efficiency 80%–95%) Water usually pumped from underground and sprayed from mobile boom with sprinklers.

Conservation: By Citizens

 _{Description: Saving the water we have}  _Methods:

 _Recycling

 _{Conserving at home}  _Xeriscaping 

 _{Fix leaks}  _Benefits:

 _{Saves money}  _{Saves wildlife}  _Problems:

 _{Bothersome to people}  _{Lack of caring}