Presentation on theme: "A Comparative Study of Water Quality and Aquatic Macroinvertebrate Diversity in the Rio Grande and its Ditches By Lian Liu Mentor: Ayesha Burdett."— Presentation transcript:
A Comparative Study of Water Quality and Aquatic Macroinvertebrate Diversity in the Rio Grande and its Ditches By Lian Liu Mentor: Ayesha Burdett
Invertebrates As Indicators Invertebrate populations often used as way to measure human disturbance and water quality Diversity is also an indicator of water quality EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa common sign of good water quality Oligochaetes indication of poor water quality Can this be applied to the Rio Grande?
The Burning Questions Will there be a significant difference between the invertebrate diversity and abundance in the Rio Grande compared to the ditches? – Yes. The Rio Grande will have greater diversity and more abundance. Will these factors be dependent on vegetation type or flow rate? – Yes it will depend on both. Are invertebrates actually a good indication of water quality? – Yes because they are directly affected by changes in physicochemical properties
The Sites of Research River Sites Ditch Sites Willow Salt Cedar Russian Olive WillowSalt Cedar Russian Olive
Instruments and Materials A throw trap with an area of cm X cm was made A meter stick A dip net Bottles for water samples and specimen 70% Ethanol to preserve and kill specimen A dissecting scope Taxonomic Keys
Procedure A water sample is taken and chemical analysis done for Nitrate and Phosphate Then the water level is measured The throw trap is set The throw trap is placed at three different locations per site The dip net is used to sample until no specimen are found Then the specimen are IDed to genus or family
Data Analysis ANOVA and regression were used to analyze the relationship between variables SPSS 17.0 was the program of choice Intolerance values for macroinvertebrates borrowed mostly from Hilsenhoff (1988)
Results Mean Richness Mean Abundance
An Idea of the Diversity No Plecoptera found River had more Genera of EPT taxa than Ditch Only Willow vegetation types had both Ephemeroptera and Trichoptera genera Salt Cedar overall lowest in richness
Mean Odonata Taxonomic Means Coenagrionidae: 9 Gomphidae: 1 Baetidae: 4 Ephemerellidae: 1 Mean Ephemeroptera Mean Trichoptera Hydropsychidae: 3 Leptoceridae: 4
Oligochaeta: 8 Taxonomic Means Cont. Mean Chironomidae Mean Annelids Blood Red Chironomidae: 8 Other Chironomidae: 6
Nitrate and Phosphate Levels
Depth and Flow Flow vs. Mean Richness Flow vs. Mean Abundance Logged
So What? A Discussion of the Results The results are inconsistent with the initial hypothesis – The ditch was more taxonomically rich than the river though not by much. – Nitrate and Phosphate levels were not correlated with richness and abundance Some results were as expected – River more rich in intolerant taxa while the ditch was more rich in tolerant taxa There was a difference between vegetation types and abundance as well as richness
So What Does That Mean? The ditch and river contain two distinct communities of macroinvertebrates The ditch has harsher living conditions compared to the river. Salt cedar sites have communites of low taxonomic richness and abundance.
Relating the Results and Further Research Vegetation types and not just the water itself can impact the abundance and richness of an aquatic environment Though communities at different site types can be different it does not mean richness is lost For further research more water chemistry such as pH and salinity could have been taken In addition, other factors such as discharge, precipitation, and a numerical instead of a categorical approach to flow rate could be done
Acknowledgements National Science Foundation Sevilleta LTER 2009 REUs and Interns Jennifer Johnson Ayesha Burdett Ben Specter Cathy McQueen UNM Department of Biology US Fish and Wildlife
References Carter, J.L., Resh, V.H., Hannaford, M.J., and Myers, M.J Macroinvertebrates as Biotic Indicators of Environmental Quality. Pages in F. R. Hauer and G. A. Lamberti (Eds.) Methods in Stream Ecology. Elsevier Science & Technology Books. Merritt, R.W. and Cummins, K.W (eds.) An Introduction to the Aquatic Insects of North America, 2 nd ed. Kendall/Hunt Publishing Company, Dubuque, IA. Peckarsky, B.L., Fraissinet, P.R., Penton, M.A., and Conklin Jr., D.J (Eds.) Freshwater Macroinvertebrates of Northeast North America. Cornell University Press, Itaca, NY. Rosas, I., Mazari, M., Saavedra, J., Báez, A.P Benthic Organisms as Indicators of Water Quality In Lake Patzcuaro, Mexico. Water, Air, and Soil Pollution 25: Smith, D.G Pennak’s Freshwater Invertebrates of the United States: Porifera to Crustacea. Jon Wiley & Sons, Inc., New York, NY.