Lake Titicaca

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Lake Titicaca

• Blake Brown
• 3-29-07

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What is Discussed

• Where is Lake Titicaca
• What is a management issue related to Lake
  Titicaca
• Discuss a case study that analyzes decomposition
  rates with response to sewage pollution and
  location

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Lake Titicaca South America
Lake Titicaca
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Lake Titicaca
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Ramis River
Puno Bay
Lake Titicaca
Mean Depth 107m Maximum Depth 284m Surface
Area 8,300 sq. km Altitude 3,182m Volume
893 billion cubic m Basin Area 150,000 sq.
km (Titicaca-Desaguadero-Poopo-Coipasa Basin)
Rio Desguadero
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Management Issue

• One of the Water Management issues of Lake
  Titicaca is the WATER BUDGET
• Water allocation and use
• Types
• Environmental
• Social
• Economic
• Hydrological
• The Water Budget is an international Issue
  between Peru and Bolivia

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Water Budget

• Largest freshwater lake in S.A. highest of
  worlds large lakes
• Lake altitude brings with it Low humidity, low
  air pressure, and high radiation levels.
• Causing a large amount of evaporation
• Population concentrations around Lake Titicaca
  affect the amount of water use as well.

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Water Budget

• Significant drops in Lake level could have
  detrimental effects on salt marsh and wetland
  ecosystems

• Ways for Improvement
• Improved stakeholder participation
• -i.e. improved education, lowering poverty
  level, involvement with issues
• Related to the water
• International fund raising
• -recommended to overcome limitations due to
  national poverty

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Intro to Case Study

• Spatial Variability of the decomposition rate of
  Schoenoplectus tatora in a polluted area of Lake
  Titicaca
• Costantini, Maria Letizia
• -University of Rome-Dept. of Genetics and
  Molecular Biology

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What is being Analyzed

• The decomposition of Schoenoplectus tatora in
  Inner Puno Bay with spatial reference to an area
  of water polluted with wastewater.
• Tatora is one of the most abundant macrophytes in
  Inner Puno Bay
• Tatora is harvested for cattle fodder, for
  roofing, handicrafts, rafts, and island
  construction.
• Inner Puno Bay makes up 2.1of the Lake and is
  one of the most vulnerable areas of the lake.

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Tatora
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• Decomposition
• Depends on biotic and abiotic factors
• Makes very sensitive to water pollution
• Effects the release of nutrients for use by
  Primary producers
• Micro-organisms and detritivores play key role
• Goals
• -Measure the decomposition rate taking into
  account critical env. factors such as temp.,
  dissolved O2, pH, wave action, depth, and sources
  of pollution
• -to map the decomposition rate through
  geostatistics for evaluating spatial
  heterogeneity in the water body as a tool for the
  future management of this ecosystem

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Inner Puno Bay
Area of Interest
Sampling conducted On 21 sites with litter bags
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Data Collection

• 21 sampling sites chosen randomly from a 400 sq m
  grid in Inner Puno Bay
• Each site with 6 litterbags anchored
• 3 UP (unprotected) with 7mm mesh nets
• 3 P (protected) with 0.1mm mesh nets
• With one of each removed at 7,28,and 56d
• Used dried Tatora, Brown fragments 15cm long in
  bundles that had a mass of 10g(0.005 variance)
• Litterbags pulled out and then weighed using AFDM
  (Ash Free Dry Mass)
• pH, temp., dissolved O2, water transparency,
  effective fetch and pollution source location all
  analyzed at time of collection

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Data Analysis

• Data analyzed through simple exponential model
  and the composite exponential model.
• Half-life, time necessary for detritus mass to
  reduce 50 was used to show regression
• Semivariograms were also conducted to show
  geographical distance between sites.
• Geostatistical data performed through GS version
  5.1.1

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Results
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Results

• Three Principle components
• 1) pH, Water transparency, and fetch (46.8)
• 2) Invertebrate abundance and water depth
  (24.3)
• 3) Water temp and Dissolved O2 (14.9)

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Results

• Animal Effects
• -UP-4 species of Amphipods 4 taxa
• of mollusks
• -Amphipods dominant (90)
• Difference between UP and P litterbags decreased
  with increased animal abundance.

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Results
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Spatial variance
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Conclusions

• Tatora decomposed slowly, but the mass loss rate
  increased with increasing water temperature and
  at high invertebrate density
• Mass loss rates were spatially auto-correlated
  and their spatial distribution showed
  functionally heterogeneous areas within the Inner
  Puno Bay.

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Conclusions

• The half life differed, but a greater variance
  was seen further away from the waste water sewage
  pollution sources
• Variations were also higher when tatora was
  exposed to invertebrate feeding and wave action

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What you should know

• Where Lake Titicaca is located.
• What a Water Budget is and that the Peruvian and
  Bolivian governments are working together with
  lake management.
• What affects decomposition of Schoenoplectus
  tatora in Lake Titicaca

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References

• Consantini, M.L., Sabetta, L., Mancinelli, G.,
  Rossi, L. 2003 Spatial variability
• Of the decomposition rate of Schoenoplectus
  Tatora in a polluted area of
• Lake Titicaca. Journal of Tropical Ecology
  (2004) Cambridge U Press.
• Global Nature Fund. 2002. http//www.globalnatur
  e.org/docs/02_vorlage.asp?id19504domid1011s p
  Eaddlastidm111089m211103m311178m419440m
  51950 4. Last updated 3/22/07.
• Revollo, M. F., SERECO. La Paz, Bolivia.
  Experience and Lessons Learned Brief
• Lake Titicaca. Maximo Laiberman Cruz (p.
  378-387).
• Revollo, Mario M. (2001). Management Issues in
  the Lake Titicaca and Lake Poopo System
  Importance of developing a Water Budget. Lakes
  and ReservoirsResearch and Mangement. Volume
  6, Isuue 3, p225-229 Sept. 2001.
• Ronteltap, Mariska. Management Efforts at Lake
  Titicaca. The Science and Politics of
  International Freshwater Management. SS 2004 and
  WS 2004/05.