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(W/FF232) Application of river invertebrate biomonitoring techniques in the Dominican Republic. Soldner, Michael1, Stephen, Ian1, Angus, Robert1, Ramos, Litay2, Grosso, Albania3, Crane, Mark1, 1 2 3 ABSTRACT- The applicability of biological fresh water quality assessment methods in tropical small-island states was assessed by collecting macroinvertebrate samples from 26 river sites within the Dominican Republic's Yaque del Norte river basin. Environmental data on geographical, physical and chemical variables were also collected from each site. Measures of richness, enumerations, diversity and biotic indices were applied to evaluate the impact of pollution on the benthic macroinvertebrate fauna as indicated by these metrics. The biological monitoring working party (BMWP) score and the adapted total score for total numbers of Ephemeroptera, Plecoptera, and Trichoptera (EPT) performed best. Community data sets were ordinated by detrended correspondence analysis and non-parametric multi-dimensional scaling. Principal components analysis was applied to investigate patterns in multiple abiotic variables between sites. Complementary analyses were used to link the biotic and abiotic data sets and determine the factors that are most influential in determining site similarities. A clear pattern emerged indicating a defined change in macroinvertebrate community structure with decreasing water quality. A causal relationship could not be derived in the present baseline study, since other environmental variables such as altitude, distance from source, and temperature were correlated with water quality and changed along similar gradients. The tools applied during all stages of this study have proven very effective and reliable. It is thus proposed that these tools can be applied with great benefit to water management programs in developing tropical island nations. Key words: biomonitoring, macroinvertebrates, biotic score, multivariate |
