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Bolivia deployed the first automatic hydro-meteorological monitoring buoy in the Titicaca Minor Lake on June 28, 2019
Prepared by Xavier Lazzaro (IRD/BOREA)
On Thursday, June 27, 2019, a truck unloaded on a beach in Huatajata two huge crates containing more than one ton of state-of-the-art electronic equipment. A group of university specialists, Dr. Xavier Lazzaro, lake ecologist researcher at IRD-France, MSc. Viviana E. Cruz Hernández*, William G. Lanza Aguilar* and Javier A. Maldonado Alfaro*, young associate researchers from the Institute of Ecology (*IE) and the Institute of Geographical Research (**IIGEO) of UMSA, with the technical support of Eng. Pierre Sterling, sales director of the manufacturer XYLEM Analytics Inc./USA for Central and South America, will assemble and deploy the first autonomous buoy-platform (called 'My Buoy', the translation of 'Mi Boya' in Spanish) for automatic high frequency monitoring of water quality and meteorological conditions of Lake Titicaca!
Figure 1 - Launching of the hydro-meteorological buoy on the shore of Huatajata.
Why an autonomous automatic buoy?
Lake Titicaca, especially its shallow littoral areas, is heavily impacted by the effects of climate change and human activities, especially domestic and industrial pollution from the city of El Alto, through the waters of the Katari river basin discharged into Cohana Bay and Minor Lake.
Global warming, nitrogen, phosphorus and organic matter inputs alter the biogeochemical and ecological functioning and aquatic biodiversity, endangering most of the endemic (native or local) species of the Altiplano. Consequently, the constant supply of nutrients and organic matter increases the level of productivity of the lake's phytoplankton microalgae. In fact, with such intense solar radiation (visible plus ultraviolet) at almost 4,000 m altitude, during the day through photosynthesis, the microalgae are the first to benefit from the nutrient input, increasing their biomass and oxygenating the water column. These primary producers are the base of the aquatic food chain. Bacteria mineralize organic matter and, conversely, consume dissolved oxygen. Some can produce toxic gases, such as sulfate-reducing bacteria that produce a potent neurotoxic gas, the hydrogen sulfide (H2S), which smells like rotten eggs.
At night, the respiration of consumers (zooplankton, macro-invertebrates, fish, among others) also depletes oxygen, which can become limiting in the early morning. In extreme conditions of strong nutrient input, certain green microalgae and cyanobacteria can proliferate. They form a surface layer ('bloom') that does not allow solar radiation to pass through at depth and inhibits oxygen exchanges with the atmosphere. The lack of light at the bottom impairs the survival of submerged plants (macrophytes), such as Charas, which also consume nutrients and oxygenate the water. In turn, the reduction of dissolved oxygen, already reduced by 30% due to the altitude in relation to sea level, is deadly for these consumers.
Figure 2 - Diagram of the conditions of Titicaca Lago Menor: A) Undisturbed conditions: Phytoplankton not very abundant at the surface, submerged Charas in good condition, good oxygenation (O2). B) During the acute eutrophication event of 2015: massive nutrient inputs (NO3, PO4), proliferation of phytoplankton (green surface layer), deoxygenation, increased carbon dioxide (CO2), release of hydrogen sulfide (H2S) toxic to aquatic life, collapse of the Charas.
The evolution of this subtle balance of processes deserves to be studied in order to anticipate future responses of the lake, and to develop measures to control undesirable phenomena. For this, it is necessary to monitor the behavior of key parameters in the water. The most important are: dissolved oxygen concentration (-), temperature gradient (+) (increasing temperature reduces oxygen solubility), dissolved organic matter concentration (+), transparency (-) or turbidity (+), pH (+), chlorophyll-a major photosynthetic pigment of algae (+), proportion and concentration of cyanobacteria in phytoplankton (+), conductivity (+). The increase (+) or decrease (-) of these parameters reveals a deterioration of water quality, called 'eutrophication'. This does not take into account the pollutants themselves. These parameters are influenced by atmospheric conditions, such as: the strength of the wind capable of mixing and cooling the water column, the intensity of solar radiation (altered by cloud cover) that heats the surface, atmospheric pressure that regulates oxygen dissolution, rainfall (rain, snow, hail) that provides nutrients, among others. The responses of microorganisms (micro-algae, bacteria) to variations in environmental conditions are extremely rapid. They are capable of doubling their densities in hours or days. Manual measurement and sample collection campaigns are time consuming, require logistics (vehicle, boat, equipment) and are costly. They can only be performed 1-2 times per month, and during part of the year. This is insufficient to anticipate the dynamics of these organisms and eutrophication phenomena. Therefore, it is necessary to complement regular surveys at a few representative stations with high frequency automatic sampling throughout the water column at a central station that integrates the variability of conditions in the area of interest. Advances in technology, improved sensitivity and miniaturization of the sensors, reliability of the probes, robotics, computer programming, Internet, speed and coverage of the cellular network, greater efficiency of solar panels, now allow the design of perfectly autonomous and automatic platforms. The buoy deployed in Lago Menor is the example. The transmission of data via ENTEL's cellular network to our servers at UMSA in La Paz, allows us to have an almost real-time view of the lake, being able to take action if necessary. With this technology, Lake Titicaca is now instrumented (equipped) like most of the other Great Lakes of the world.
Where is the HydroMet buoy ('Mi Boya') Located?
The Northeast region is the shallowest, most populated region of Lago Menor, where the phytoplankton microalgal bloom occurred in April-May 2015. In this region, the daily warming of the shallow water mass invariably causes early afternoon thermal winds that increase in intensity. They can reach speeds of up to 10 m/s (36 km/h), sufficient to mix the water column down to 5-m depth. This mixing causes the resuspension of nutrients and organic matter deposited on the bottom. This phenomenon makes this region the most favorable for generating blooms of phytoplankton microalgae. For this reason, it was chosen to deploy the buoy. It is anchored at a depth of 11 m, found in the submerged ex-bed of the northern arm of the Katari River, in a zone of 8 m depth on average. This location allows studying the dynamics of daily vertical gradients in dissolved oxygen, temperature, organic matter and chlorophyll-a, generated by meteorological conditions.
Figure 3 - Map of the OLT observatory research site, including the location mark (in red) of the HydroMet Buoy ('Mi Boya').
The inaugural Lake Ceremony of the HydroMet buoy deployment
To present 'Mi Buoy' ('Mi Boya') and its operation to the State institutions, local authorities and riparian populations, an inaugural Lake Ceremony was organized on Friday June 28, 2019. As this buoy measures both hydrobiological and meteorological parameters, it was called the 'HydroMet Buoy' (for 'hydrometeorological') in technical language. For the general public it is 'My Buoy' because it is a heritage of the inhabitants of the Lake that informs them of its state of health. It also has its name in Aymara 'Qamaskiua ch'uwa quta mama', chosen by the native communities themselves.
Isaac Callizaya Limachi, Secretary of Environment and Cultures of Puerto Pérez. Representatives of the Ecology (IE), Hydraulics and Hydrology (IHH), Chemical Research (IIQ) and Geographical Research (IIGEO) Institutes of UMSA - Universidad Mayor de San Andrés in La Paz, the Operational Unit of Bolivia (UOB), the Katarí Watershed Management Unit (UGCK) and the General Directorate of Planning (DGP/UEE) of MMAyA - Ministerio de Medio Ambiente y Agua, Eng. Grover Huallpa Aruquipa, UNDP IWRM project coordinator at the Bolivian Ministry of Foreign Affairs (MRE), Eng. Rolando Urahola, Director of the Instituto Público Desconcentrado de Pesca y Acuícultura (IPD-PACU) for the Altiplano, the technicians of the Servicio Nacional de Meteorológia e Hidrología (SENAMHI), Eng. Federico Chipana, the communicator of the La Vida project, Lic. Juan José Ocola Salazar, Executive President, and Eng. Valentin Fernández, Plan Director, and technicians at ALT - Autonomous Binational ,Authority of lake Titicaca, Prof. Eliana Ballivian Ríos, UNDP IWRM project communicator, Lic. Analía Guachalla Terrazas, coordinator of the UNDP technical liaison for Bolivia, Eng. Gonzalo Lora Viezaga, former binational scientific coordinator of the UNDP IWRM project, Mr. Denis Gaillard, French Ambassador in Bolivia and Mr. Patrick Riba, Head of the French Cooperation, Eng. Cenaida Ramos Poma, representing the National Water Agency in Puno Peru, Architect Hugo Zea Giraldo, coordinator of the QOTATITI platform of the Peruvian society, the local authorities of Puerto Perez, Mr. Felix Mendoza, Secretary General of the Quehuaya Island, Mr. Felix Mendoza, Secretary General of the UNDP IWRM project, Mrs. Virginia Mamani of the Central Agrarian Union of the Suriqui Island Bartolina Sisa, from Huatajata and Tiquina, with journalists from the press: Canal 13 TV Universitaria, RTP Bolivia, the Foundation for strategic research in Bolivia (PIEB), the Association of Journalists of La Paz, and France 24. On Google, view notes and video reports, including the words 'Titicaca buoy'.
Next to the buoy, Comadre Adela, Spiritual Guide of Copacabana, performed an ancestral lake ceremony of good wishes for the team, participants, institutions, research projects, monitoring and restoration of the Lake. Mr. Lorenzo Inda, Uru representative in Desaguadero, welcomed the participants on the floating reed (Totora) island of Quehuaya, communicating the concern of the native people regarding the increasing pollution. In total there were 60 participants, aboard 3 boats piloted by Mr. Natalio and Mr. Ariel Esteban, from Suriqui, and Mr. Máximo Catari Cahuaya from Huatajata.
Figure 4 - Inuagural lake ceremony of the HydroMet Buoy ('Mi Boya') deployment.
The Bolivian Navy provided support with a vessel from the Huatajata Naval Captaincy. On board the buoy, Eng. Pierre Sterling (XYLEM Inc.) and Dr. Xavier Lazzaro (IRD) described the technical characteristics of the buoy, the parameters to be measured, the frequency of data acquisition, what it is used for, the benefits for the inhabitants, scientists and decision makers, and why it was deployed in this area? Due to the strong waves and wind, it was not possible to show the functioning of the different internal elements of the buoy, such as the vertical profiler and the multiparameter probe. Despite the use of megaphones, it was difficult to communicate with the audience in the boats. Therefore, after a trial period of about two months, another technical workshop will be organized at the UMSA Campus in Cota Cota, to train teams from UMSA, MMAyA, SENAMHI and ALT, among others.
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