Effect of mechanical removal of water hyacinth (Eichhornia crassipes) on the water quality and biological communities in a Mexican reservoir
Keywords:
weed control, plankton, nekton, freshwaterAbstract
The Valsequillo reservoir, located near the city of Puebla, Mexico, is a hard-water eutrophic subtropical system, with minimum temperatures in winter (November–December), and marked dry-rain seasons with fluctuating depth. The reservoir has been infested with water hyacinth for over three decades. A management program involving the use of triturating machines was applied from December 1996 to February 1997. After trituration, remains were allowed to settle to the bottom. The purpose of this study was to monitor the changes in the water quality and the biological communities before and after physical control of weeds. A monthly sampling of surface water was performed at four stations one year before the treatment. After trituration, one year sampling was also carried out. Variables measured included temperature, Secchi disk transparency, depth, pH, dissolved oxygen, oxygen saturation, hardness, nitrate content, nitrite content, ammonia, orthophosphates, and numerical abundance of phytoplankton, zooplankton, and nekton.
Weed control affected changes in all variables measured, as a result of residual decomposition of triturated matter. Secchi transparency and oxygen levels decreased and pH became slightly more alkaline. More important changes occurred for nutrients. Orthophosphate concentration increased, for nitrate and nitrite, increase was about 320% and 450% respectively. Ammonia reached lethal values for at least four months after trituration. As a result, phytoplankton decreased initially, and when it flourished again, the Bacillariophyta were replaced by Cyanophyta. Euglenophyta were important in both years. Of zooplankton, calanoids decreased, but cyclopoids and cladocerans maintained similar numbers, although the latter group changed in composition in that Ceriodaphnia was replaced by Moina. Fish disappeared from the system after weed trituration. In the second year a small recovery of water quality occurred, but water hyacinth also started to develop again. At present, Valsequillo is again covered by water hyacinth.
References
Aldama, R. A. 2000. El control de las malezas acuáticas. Desarrollo sustentable, 1(1): 3–5. (Aquatic weed control. In Spanish)
Center, T. D., Dray, F. A., Jubinsky, G. P. and Grodowitz, M. J. 1999. Biological control of water hyacinth under conditions of maintenance management: Can herbicides and insects be integrated. Environ. Man., 23: 241–256.
Charudattan, R. 2001. Are we on top of aquatic weeds? Weed problems, control options, and challenges. World's Worst Weeds, 77: 43–68.
Gutiérrez, E., Arreguín, F., Huerto, R. and Saldaña, P. 1994. Aquatic weed control. Int. J. Water Res. Develop., 10: 291–312.
Gutiérrez, E., Huerto, R., Saldaña, P. and Arreguín, F. 1996. Strategies for water hyacinth (Eichhornia crassipes) control in México. Hydrobiologia, 340: 181–185.
Hutchinson, G. E. 1969. “A Treatise on Limnology”. In Introduction to Lake Biology and the Limnoplankton, New York: John Wiley and Sons.
Hütter, L. A. 1988. Wasser und Wasseruntersuchung, Frankfurt: Verlag Moritz Diesterweg.
Lugo, A., Bravo-Inclán, L. A., Alcocer, J., Gaytán, M. L., Oliva, M. G., Sánchez, Ma. del R., Chávez, M. and Vilaclara, G. 1998. Effect on the planktonic community of the chemical program used to control water hyacinth (Eichhornia crassipes) in Guadalupe Dam, Mexico. Aquat. Ecosyst. Health Manag., 1: 333–343.
Miller, R. R. 1974. Mexican species of the genus Heterandria, subgenus Pseudoxiphophorus (Pisces: Poecilidae). Trans. San Diego Soc. Nat. Hist., 17: 235–250.
Ortega, M. 1984. Catálogo de algas contientales recientes de México, Universidad Nacional Autónoma de México, México, D.F.,
Pennak, R. 1989. Fresh-Water Invertebrates of the United States, USA: Wiley & Sons.
Prescott, G. 1973. Freshwater Algae.. The Picturekey Nature Series, USA.,
Reid, G. K. 1960. Ecology of Inland Waters and Estuaries, New York: D. Van Nostrand Co..
Tavera, R. and Castillo, S. 2000. “An eutrophication-induced shift in the composition, frequency and abundance of the phytoplankton in Lake Catemaco, Veracruz, Mexico”. In Aquatic Ecosystems of Mexico, Status and Scope, Edited by: Munawar, M., Lawrence, S. G., Munawar, I. F. and Malley, D. F. pp. 103–117. Leiden: Backhuys Publishers.
Tiffany, L. and Briton, M. 1971. The Algae of Illinois, New York: Hafner Publishing Company.
Umaña, G. and Collado, C. 1990. Asociacion planctónica en el embalse Arenal, Costa Rica. Rev. Biol. Trop., 38(2A): 311–321.
Woomer, P. L., Muzira, R., Bwamiki, D., Mutetikka, D., Amoding, A. and Bekunda, M. A. 2000. Biological management of water hyacinth waste in Uganda. Biol. Agric. Hortic., 17: 181–196.
Published
Issue
Section
License
Manuscripts must be original. They must not be published or be under consideration for publication elsewhere, in whole or in part. It is required that the lead author of accepted papers complete and sign the MSU Press AEHM Author Publishing Agreement and provide it to the publisher upon acceptance.
