P1.189 Wednesday, Jan. 4 Abundance and Variation of Invertebrate Zooplankton in a Georgia Estuary HOWELL, A.L.*; FRANCIS, JR., A.W.; Armstrong Atlantic State Univ., Savannah, GA email@example.com
Zooplankton is an essential source of nutrition for larval and juvenile fishes as well as many adult planktivores. While temporal patterns of zooplankton occurrence and abundance have been described for many coastal environments, these temporal patterns have not been well examined within the estuaries where many larval and juvenile fishes occur. It was the purpose of this investigation to identify and describe the temporal occurrence and abundance of invertebrate zooplankton in the Moon River, a salt marsh based estuary south of Savannah, Georgia. From July 2009 until July 2010, weekly collections were made with a 3:1 zooplankton net having a 0.5-m diameter hoop and 0.5-mm mesh. The net was deployed in the water column just below the surface after sunset and before sunrise during a night flood tide. A flow meter was also deployed to measure water volume sampled. Zooplankton samples were vital stained with neutral red and subsequently fixed in 10% formalin. During collections, measurements were made of environmental conditions, including water depth, salinity, temperature, dissolved oxygen, and pH. In the lab, samples were sorted and identified to the lowest possible taxonomic level. Major invertebrate zooplankton included assorted copepods, mysid shrimp, amphipods, hydromedusas, cumaceans, and marine mites. Temporal patterns include mysid shrimp peaking in abundance in January (647) and May (646) of 2010. Amphipod abundance showed an increase in September 2009 (58) with a spike in abundance in May (123) and June (96) of 2010. Future work will compare temporal patterns of zooplankton occurrence and abundance with larval and juvenile fish occurrence and abundance.