Aquatic ecology of two subarctic lakes: Big and Little Minto Lakes, Alaska

Abstract

During 1988, three sampling trips were made to Big and Little Minto Lakes to study their limnological features. Physical and chemical measurements were made of both lakes, while the invertebrate community and habitat characteristics were investigated along Big Minto Lake's shoreline (5-35cm water depth) . Both lakes are shallow and eutrophic, with high dissolved oxygen and pH, and moderate alkalinity. Invertebrate abundance averaged 7,352/m2 (±SE = 406, n = 60) , and was dominated by Diptera (38%) . Gastropoda comprised the largest portion (41%) of total biovolume (11.28 mL/m2, ±SE = 1.28, n = 60). Diptera and Coleoptera contained the majority of invertebrate families. Scrapers (41%) and collectors (23%) dominated the food web in biovolume. Overall, invertebrate abundance was significantly correlated with low detritus biomass; however, Trichoptera abundance was significantly correlated with low vegetation biomass, shallow water, and the August sample period; and both diversity indices, were significantly correlated with aquatic plant biomass (AFDW).