Identifying Phytoplankton Classes In California Reservoirs Using HPLC Pigment Analysis

Abstract:

Few bodies of water are routinely monitored for phytoplankton composition due to monetary and time constraints, especially the less accessible bodies of water in central and southern California. These lakes and estuaries are important for economic reasons such as tourism and fishing. This project investigated the composition of phytoplankton present using pigment analysis to identify dominant phytoplankton groups. A total of 28 different sites with a wide range of salinity (0 - 60) in central and southern California were examined. These included 13 different bodies of water in central California: 6 in the Sierras, 7 in the San Francisco Bay Estuary, and 15 from southern California. The samples were analyzed using high-performance liquid-chromatography (HPLC) to quantify the pigments present (using retention time and the spectral thumbprint). Diagnostic pigments were used to indicate the phytoplankton class composition, focusing on diatoms, dinoflagellates, cryptophytes, and cyanobacteria - all key phytoplankton groups indicative of the health of the sampled reservoir. Our results indicated that cyanobacteria dominated four of the seven bodies of central California water (Mono Lake, Bridgeport Reservoir, Steamboat Slough, and Pinto Lake); cryptophytes and nannoflagellates dominated two of the central California bodies of water (Mare Island Strait and Topaz Lake); and diatoms and dinoflagellates dominated one central California body of water, Oakland Inner Harbor, comprising more than 70% of the phytoplankton present. We expect the bodies of water from Southern California to be as disparate. Though this data is only a snapshot, it has significant implications in comparing different ecosystems across California, and it has the potential to provide valuable insight into the composition of phytoplankton communities.