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Changes in Aquatic Invertebrate Community Diversity during Supra-Seasonal Drought Conditions. By Briana Albini University of Hawaii at Hilo Mentor: Ayesha Burdett New Mexico Museum of Natural History and Science. Droughts. Seasonal droughts Occur periodically/ seasonally.
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Changes in Aquatic Invertebrate Community Diversity during Supra-Seasonal Drought Conditions By Briana Albini University of Hawaii at Hilo Mentor: Ayesha Burdett New Mexico Museum of Natural History and Science
Droughts • Seasonal droughts • Occur periodically/ seasonally • Supra-seasonal droughts • Random & longer than normal seasonal conditions • Considered a ramp disturbance • Due to increase of disturbance over time
Invertebrates • Inverts evolved adaptations to seasonal drought • Extreme conditions produced by supra-seasonal drought may be too much for invertebrates to handle DipteraChironomidae HemipteraCorixidae
Water and drought • Increase in temperature, nutrient and chemical loads • Decrease in D.O., surface area and volume of water body • Lotic and lentic habitat ratio change • Refugia can be pockets of standing water
Past Study on Invertebrates • Studied differences in invertebrate composition in drinkers & springs • Using data from 2010
Questions • Is there a difference between the diversity levels of invertebrate communities in the springs and drinkers due to drought conditions between 2010 and 2013? • Additional Questions: • Can drinkers be considered refugia? • Do some inverts stay dormant in dried sediments until area is wet again?
Methods • Experiment was conducted on Sevilleta National Wildlife Refuge
Wet Sites • Collection of aquatic invertebrates • Left sponges in water sources for 10 days • Took a 15x15cm quadrate sample from bottom of water source
Dry Sites • Total of 3 dry sites • Rio Salado • Bronco • Cibola • Collection of sediment samples • Took top soil or sediment from drinkers or springs
Wet Sites Lab Methods Dry Sites Lab Methods • Separate invertebrates from sediment • Identify & count amount of each taxa • Place sediment into clear containers & add water • After 10 days, go through sample to see what emerges • Identify any emergent taxa Methods – Lab Analysis
Methods – Vegetation & Scat Survey • Same methods for both surveys • 4 transects going in cardinal directions • Each transect is 50 m • 10 - 1 m quadrates spaced 5 m apart • Surveyed for % coverage of vegetation and scat
Results Ostracoda
Results • No correlation • Positive correlation
Results for Dry Samples • No emergent taxa found • May indicate that the environment is too harsh to keep ‘seedbanks’
Total Species Pool Bronco 2010 S=3 Total Species Pool McKenzie2010 S=1 Turnover 3 1 3 0 0 1 Bronco 2013 S=0 McKenzie 2013 S=2 0 1 Total Species Pool Cibola2010 S=10 10 10 0 Total Species Pool San Lorenzo E. 2010 S=7 Total Species Pool Goat Draw2010 S=1 1 7 Cibola 2013 S=0 0 7 0 0 1 San Lorenzo E. 2013 S=11 Goat Draw 2013 S=2 11 1
Turnover Total Species Pool Canyon2010 S=6 Total Species Pool Gibbs 2010 S=1 6 1 6 1 0 0 Gibbs 2013 S=1 Canyon 2013 S=1 1 1 Total Species Pool Tule 222 2010 S=7 Total Species Pool West Mesa 2010 S=3 7 3 6 2 1 1 Tule 222 2013 S=3 West Mesa 2013 S=4 2 3
Discussion • There is no difference in taxa richness between 2010 and 2013 • Not enough springs to answer refugia question • Dry springs have no invertebrate ‘seedbanks’
Improvements? • More springs to compare to drinkers • Need wetter conditions • Couldn’t look into refugia question • Switch methods • Sponge removed and quadrate sample taken on same day • Abundance numbers from past study
Future Study • Resample wet drinkers and springs • Use additional points to see how turnover changes • How diversity of drinkers and springs change
Acknowledgement • Thank you all very much! • NSF, Sevilleta LTER Program and the US Fish & Wildlife • Research Mentor: Ayesha Burdett • Past Data: Amanda Martinez & Scott Collins • Field Partner: Brennan Davis • Sevilleta Coordinator: Amaris Swann • Becky Bixby (UNM) & Bob Verb (ONU) • And to everyone else who helped & supported me this summer!
Thank You!!! TrombidiformesHydrachnidaeHydrachna