CECOAL   02625
CENTRO DE ECOLOGIA APLICADA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Macroinvertebrates as indicators of biological integrity in subtropical urban wetlands (Argentina).
Autor/es:
POI, ALICIA SUSANA GUADALUPE; GALLARDO, LUCIANA IRENE; CORONEL, JUAN MANUEL
Lugar:
Quito
Reunión:
Congreso; Congreso AQUATROP. Ecosistemas acuáticos tropicales en el antropoceno.; 2018
Institución organizadora:
Universidad de San Francisco de Quito (USFQ)
Resumen:
In north-east Corrientes Province, there are more than 50 000 semi-rounded shallow rain-fed lakes. Several lakes have been impacted by human disturbances, mainly, because urbanization causes eutrophication due to the illegal wastewater discharge from neighboring areas. To assess the effects of urbanization on the biological integrity of lakes, we compared 22 metrics based on structural attributes of macroinvertebrates associated with Egeria najas across seasons in 5 lakes with different human disturbance levels. Samples of E. najas and associated invertebrates were collected seasonally using a net of 962 cm2, for a total of 66. Eight major groups of macroinvertebrates belonging to 35 families were recorded. The total macroinvertebrate abundance and the family richness were significantly higher in less disturbed lakes, but the differences between seasons were not significant. The use of plant dry weight as a unit of reference allowed for differences in macroinvertebrate abundance to be found between the more and less disturbed lakes, indicating that it was noticeably superior in the less disturbed lakes with similar plant volumes. Non-metric multidimensional scaling analysis differentiated the macroinvertebrate abundances between the more and less disturbed lakes. The diversity indices were not useful for measuring the changes in the studied lakes, as the macroinvertebrate assemblages had one or two dominant families and the rest at smaller proportions. Total number of taxa, number of EOT (Ephemeroptera, Odonata, Trichoptera) taxa, abundance and proportion of Trichoptera and abundance of Chironomidae reflected significant differences between the more and less disturbed lakes. Our results suggest that some invertebrate metrics respond to urbanization, and they could be used to asses biological integrity of the studied lakes in complement of chemical monitoring of water quality. Management efforts should focus on the maintenance of macrophyte stands that provide high invertebrate diversity, which serve as food for a wide variety of fish.