Lecture 18, 03 Nov 2003

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Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic
Ecosystems) Student Presentations Conservation
Biology ECOL 406R/506R University of Arizona Fall
2003 Kevin Bonine
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• Aquatic Ecosystems (CH9)
• 2. Thank you cards
• 3. Syllabus Shuffle (Bob Steidl back one class)

Readings for Wed (SDCP)
Overview of Reserve Design http//www.co.pima.az.
us/cmo/sdcp/reports/d20/096OVE.PDF Listed Species
Reserve http//www.co.pima.az.us/cmo/sdcp/reports
/d10/021LIS.PDF
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Chapter 9 group presentations Monday
8 minute highlights presentation, 2 min
QnA (board, or overhead, or powerpoint late
Sunday)
Pages
230-234 Amy Tendick, Galia Bobman, Aurora
Fabry-Wood, Leonides Corral 234-238 Ben
Joslin, Andrea Vasquez, Bridget Barker, Louise
Misztal 239-243 Christopher Deegan, Michael
Gilliland, JD Friedrichs 243-248 Dana Backer,
Cori Carveth, Sarah Hartwell, Jenna
Ramsey 248-255 Erica Sontz, Meghan Jarvie,
Ginny Newsome, Linh Nguyen 255-264 Maeveen
Behan, Justin Dodds, Lauren Merin
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230-234 Tendick Bobman Fabry-Wood Corral
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234-238 Joslin Vasquez Barker Misztal
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Conservation Challenges in Freshwater Habitats

• Eutrophication
• Acidification
• Habitat Alteration
• Invasive plant species
• Invasive invertebrates
• Invasive vertebrates

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Conservation Challenges of Freshwater Habitat
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The Issues

• Eutrophication
• Acidification
• Habitat Alteration by NISs
• Plant
• Animal

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Eutrophication

• Natural process of the aging of a lake
• In a young lake, the water is cold and clear, and
  supports little life
• Streams drain into the lake, introducing
  nutrients such as nitrogen and phosphorus, which
  encourage the growth of aquatic organisms
• The lake's fertility increases, and organic
  remains begin to be deposited on the lake bottom

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Eutrophication

• Silt and organic debris increase on lake bottom,
  lake becomes shallower and warmer, less oxygen
• Warm-water organisms supplant those that thrive
  in a cold environment
• Marsh plants take root in the shallows and begin
  to fill in the original lake basin and the lake
  gives way to a bog, and finally into land
• Depending on climate, size of the lake, and other
  factors, the natural aging of a lake may span
  thousands of years

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Eutrophication

• Pollutants from man's activities can radically
  accelerate the natural aging process
• Lakes have been severely eutrophied by sewage,
  agricultural and industrial wastes

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Eutrophication

• Primarily from increased nitrates and phosphates,
  which act as plant nutrients
• Stimulate the growth of algae
• Cause unsightly scum and unpleasant odors
• Reduction of dissolved oxygen, which is vital to
  other aquatic life
• Other pollutants flowing into a lake may poison
  whole populations of fish
• Decomposing remains further deplete the water's
  dissolved oxygen content

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Pollutants

• In 1996, the EPA reported to Congress in the
  National Water Quality Inventory
• Approximately 40 of the nation's surveyed lakes,
  rivers, and estuaries were too polluted for such
  basic uses as drinking supply, fishing, and
  swimming
• The pollutants include grit, asbestos, phosphates
  and nitrates, mercury, lead, caustic soda and
  other sodium compounds, sulfur and sulfuric acid,
  oils, and petrochemicals

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Pollutants

• Manufacturing plants pour off undiluted
  corrosives, poisons, and noxious byproducts
• The construction industry discharges slurries of
  gypsum, cement, abrasives, metals, and poisonous
  solvents
• A pervasive group of contaminants is
  polychlorinated biphenyl (PCB) components of
  lubricants, plastic wrappers, and adhesives
• Hot water discharged by factories and power
  plants causes thermal pollution, lower oxygen

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Acidification

• Hydrogen sulfide, NOx and SO2 from coal burning
  for electricity
• Nitrous oxide from car exhaust
• Combine with water to form sulfuric and nitric
  acid

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Acidification

• Rain is slightly acidic
• Buffering by carbonates, some freshwater systems
  are more susceptible to acidification
• High acidity affects reproduction of fish,
  amphibians and invertebrates
• Direct mortality
• Change in chemical reactions, metallic ions may
  precipitate out of solution
• Acidification can happen rapidly pH from 7 to 4
  in 24 hour period in Scotland during heavy rain,
  massive fish kill

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• Habitat Alteration By Nonindigenous Species
• Aquatic Enviroments Vulnerability
• Recent disturbance
• Predators absent
• Effective Competitors absent
• Invasion by Aquatic Plants
• 1. Introduction Usually by humans
• 2. Dispersal occurs after
  survival and reproduction
• 3. Adaptation via selection and
  establishment
• 4. Colonization

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• Eurasian Water Milfoil
• Reproduces vegetatively
• Often transported by Human activity
• Reproduces Rapidly

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• Distribution in the United States

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• Other Aquatic Invaders
• 1. Purple Loosestrife
• Chokes out natural vegetation in shallow water
• 2. Water hyacinth
• forms dense mats in deep water

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Animal NISs in Freshwater

• Properties
• High reproductive rates
• Wide environmental tolerances
• Large dispersal distances
• 3 Examples

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The Zebra Mussel
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The Spread of
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The Carp (Cyrinus carpio)
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The Nile Perch (Lates niloticus)
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The demise of the Haplochromis spp. of cichlid
fish
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• Take Home Lesson?
• Managers must consider that if (there are
  chemical alterations to a system or a)
  nonindigenous (species) enters a system, habitat
  management and conservation strategies may have
  to be fundamentally altered to preserve
  biodiversity.
• Van Dyke 2003 (pg 238)

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239-243 Deegan Gilliland Friedrichs
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Conserving Aquatic Habitats

• Managing Sedimentation Eutrophication

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Why?
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Mmm ...
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yummy!
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The Culprits

• Us! (surprise)

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Primary Cause Erosion

• modern agricultural runoff
• urban sewage waste disposal
• land development -- impermeability

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Sociopolitical causes need sociopolitical
remedies

• We must enact laws policies to
• Reduce chemical fertilizer use
• Remove compounds from urban discharge
• Reduce agricultural landscaping erosion

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Urban Abatement no.1
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Urban Abatement no.2
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Restoration

• Dredging
• Chemistry
• Biomanipulation

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Dredging

• Remove Purify Contaminated Sediments

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Chemistry -- Riplox method

• Oxidize sediment surface to precipitate out
  phosphorus.
• Additional reactions raise O2 levels, stabilize
  pH, encourage denitrifying bacteria in the
  sediment to release excess nitrate as gas into
  the atmosphere.

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Bioremediation
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Bioremediation continued
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Alternative Stable States
Turbidity is balanced by

• Nutrient inputs
• Fish populations
• Macrophyte Periphytic algal populations

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Thanks.
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243-248 Backer Carveth Hartwell Ramsey
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Legislation and Management for Freshwater
Environments

• Sarah, Jenna, Cori and Dana
• Monday November 3, 2003

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The Wild and Scenic Rivers Act

• Most significant legislation protecting streams
  and rivers
• Introduced in 1968

Verde River, Arizona
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What is it??

• Under this act, a stream or section of a stream
  is designated as wild and scenic

• Protected from any action by any federal agency
  that would adversely affect its water quality

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Problems

• 1990- Less than 2 of U.S. streams were deemed
  sufficient to merit protection under this act

• This means that less than 100,000km out of 5.2
  million kms are protected

San Pedro River, Arizona
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Water Pollution Control Act, 1972

• Amendment to the Clean Water Act

Directed EPA to restore and maintain the
physical, chemical and biological integrity of
the nations waters and to enhance all forms of
aquatic life

• A more biologically oriented approach to
  protecting the nations waters

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Problems

• Only chemical standards enforced
• Does not ensure that entire ecosystem is
  functional
• Many impacts that degrade aquatic systems are not
  detected by chemical monitoring

Cienega Creek, Arizona
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Indices of Biotic Integrity (IBI)

• Ecologically based measurements of water quality
• A particular taxon (i.e. fish) is rated and
  scored based on 3 different attribute groups
• Species Richness and Composition
• i.e.Number and identity of benthic species
• Trophic Composition
• i.e. Percentage of omnivores
• Fish abundance and Condition
• i.e. Number of individuals with disease, fin
  damage and skeletal anomalies

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IBIs Continued..

• Site scored and assigned an integrity class
  ranking

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Advantages

• Focuses on distinct attributes of the system

• Inexpensive

• Simple and sensitive to ecological change

• Incorporates professional ecological opinion

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International and National Legislation for
Wetlands

• Wetlands were one of the first cases in which
  international legislation focused on the
  protection of an ecosystem instead of a species.
• The Ramsar Convention, was the first global
  conservation convention to focus on the wetlands
  ecosystem. The convention obligates its signers
  to identify and designate at least one wetland in
  their country as a wetland of international
  importance and to establish wetland nature
  reserves.

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Canadas federal policy on wetland conservation
is one of the best national examples of
implementing the ideals of Ramsar and has
experienced remarkable success.
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The Canadian policy articulates strategies for
sustainable use and management of the nations
wetlands.

• Provides for the maintenance of overall wetland
  function.
• Enhances and rehabilitates degraded wetlands.
• Recognizes wetland functions in planning,
  management, and economic decision making in all
  federal programs
• Secures and protects wetlands of national
  importance.
• Uses wetlands in a sustainable manner.
• Allows no net loss of wetlands on federal lands
  and waters.

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The U.S. has designed a number of legislation
acts to address wetland conservation in an act to
increase preservation and restoration of these
areas.
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The 1985 Food Security Act, aka Swampbuster is
designed to stop the process of draining
wetlands in private agricultural lands.

• Denies most U.S. Department of Agriculture
  benefits to farmers who drain wetlands on their
  land.
• Creates an eligibility requirement for farmers to
  receive Administration loans and other benefits.

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Wetland Reserve Program (WRP)

• Provides for payment of subsidies to farmers who
  remove croplands from production in former
  wetland areas and to reestablish the land as
  wetlands
• To enroll in WRP, the landowners plan must
  include drainage alterations and the
  establishment of marsh plants on the enrolled
  site.

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Other examples of U.S. programs or acts
implemented to protect and preserve wetlands.

• Clean Water Act
• Migratory Bird Hunting and Conservation Stamps
• Federal Aid to Wildlife Restoration Act
• Wetlands Loan Act
• Land and Water Conservation Fund
• Water Bond Program
• Executive Order 11988 Floodplain Management
• Executive Order 11990 Protection of Wetlands
• Coastal Zone Management Act
• Payment-in-kind program

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Despite conservation efforts, wetlands loss in
the U.S. still continues in part because

• There is a lack of agency coordination in wetland
  conservation.
• Most legislation does not regulate private
  activity on private lands (cause of majority of
  wetland loss).
• Some U.S. legislation still encourages the
  draining of wetlands. For example the U.S. tax
  code encourages farmers to drain and clear
  wetlands by providing tax deductions for many
  types of development activities.

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Setting Priorities for Conservation in Freshwater
Habitats

• WWF-US criteria for assessment of lakes and
  streams
• 1. Biological distinctiveness
• 2. Conservation status

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• Gives priority to regions that contain systems
  that contribute to biodiversity
• 1. Globally outstanding
• 2. Continentally outstanding
• 3. Bioregionally outstanding
• 4. Nationally important
• Priority declines as the importance of the system
  decreases

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Rankings...

• I Critical (intact habitat reduced to small,
  isolated patches small probability of
  persistence over the next 10 years without
  immediate action)
• II Endangered (intact habitat of isolated patches
  with low to medium probability of persistence
  over the next 10 years without immediate or
  continuing protection)

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• III Vulnerable (intact habitat remaining in
  large and small areas, persistence is likely over
  the next 10 years with protection and
  restoration)
• IV Relatively Stable (disturbance and alteration
  in certain areas, but overall stable external
  practices unlikely to impact habitat)
• V Relatively Intact (minimally disturbed)

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Rule-Based Models

• Used to determine if habitat loss or
  environmental change are random
• Evaluate possible mechanisms of distributional
  changes in a species

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Disappearance of Frogs

• Isolation model due to distances between
  changes in distribution ponds
• Succession model changes in distribution due to
  altered vegetation in and around ponds
• Null model changes
• in distribution were
• random

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• Results of the study showed that the Succession
  Model was correct
• Frogs could best be preserved by managing the
  vegetation
• Rule-based models require minimal data, dont
  necessarily need to prove that changes in
  vegetation cause frog declines, only that
  managing vegetation may help frogs more than
  another type of plan

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248-255 Sontz Jarvie Newsome Nguyen
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Marine Habitats and Biodiversity
http//www.ucmp.berkeley.edu/vertebrates/coelacant
h/coelacanths.html
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Marine Habitats

• Intertidal
• Pelagic
• Benthic
• Abyssal

• Coral Reefs
• Estuaries
• Seagrass Beds (benthic)

http//www.onr.navy.mil/focus/ocean/regions/bluewa
ter1.htm
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Coral Reefs

• Shallow, tropical water
• 20o N and S of equator
• Indo-Pacific, Western Atlantic, Red Sea

http//www.reefrelief.org/Coral20Forest/map.html
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Coral Reefs

• Structure-coral polyps secrete calcium
• Nutrients-erosion of reefs releases calcium
• Water quality-sponges filter water
• Light-coral forms in well-lit waters, favorable
  for photosynthesis

http//www.photolib.noaa.gov/reef/reef2584.htm
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Benthos

• Ocean bottom, excluding the deepest areas
• Sand, silt and decomposing organic matter
• Often dark
• Often cold
• Nutrient rich

http//www.photolib.noaa.gov/nurp/nur00512.htm
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Seagrass Beds

• 15 decline in past decade
• Flowering plants
• Food resource, nursery, habitat
• Prevent erosion
• Reduce wave impact
• Filter water

http//www.photolib.noaa.gov/sanctuary/sanc0211.ht
m
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Hydrothermal Vents

• Mid-ocean ridges, tectonic plates
• Chemosynthetic bacteria
• Huge taxonomic diversity
• Old?
• Relict species?
• Metapopulations?

http//www.whoi.edu/institutes/doei/general/missio
n.htm
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Whale Fall Communities

• Succession of communities
• Decomposition of bones yields hydrogen sulfide
• DNA analyses of fauna
• Implications for whaling?

http//www.nurp.noaa.gov/Spotlight20Articles/whal
es.html
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Major threats to Marine Habitats

• 1. Exploitation of commercial species
• 2. Direct destruction of marine habitats
• 3. Indirect degradation of marine habitats

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1. Exploitation of Commercial Species

• Maximum Sustainable Yield (MSY)
• Used to manage fisheries as renewable resources
• Calculated based on catch per unit effort
• Reproductive surplus was the only requirement for
  a sustainable fishery
• Not used in fisheries anymore because it caused
  depletion in fish stocks

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1. Exploitation of Commercial Species

• Current Estimates
• 70 of the worlds fish stocks are exploited or
  depleted
• 45 of all species are over-harvested

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1. Exploitation of Commercial Species

• Over-harvested Populations
• Show widely ranging cycles of high and low
  abundance.
• Do not necessarily show a strong correlation
  between recruitment and number of adults present.
• Do not necessarily show advanced warning of
  population decline.

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1. Exploitation of Commercial Species Effects

• Removal of a prey species may reduce the
  populations of predators.
• Ex. Decline of sea otters in CA following
  over-fishing of abalones.
• 2. Removal of predator species disrupts
  equilibria of prey species.

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1. Exploitation of Commercial Species Effects
cont.

• 3. The take of non targeted species contributes
  to exploitation problems.
• Ex. In shrimp fisheries, the discarded by-catch
  can exceed that of the targeted catch.

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2. Direct destruction of Marine Habitats

• Examples of Direct Destruction
• The use of explosives to harvest coral reef
  species. One blast can devastate 1000m3.
• Trawling nets destroy complex and diverse
  communities on the ocean floor. (figure 9.15)

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255-264 Behan Dodds Merin
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END