Water Chemistry Factors Affecting Algal Biodiversity and Toxin Production

1. Big Canyon Creek Pre-Marsh Big Canyon Creek Post-Marsh Newport Bay Newport Valley Water Chemistry Factors Affecting Algal Biodiversity and Toxin Production Magrann, T. 1, 2*, Dunbar, S. G.1, 2, Sutula, M.3, Boskovic, D. 4  1. Department of Earth and Biological Sciences, Loma Linda University (LLU), Loma Linda, CA, 92350; 2. Marine Research Group, (LLU); 3. Southern California Coastal Waters Research Project (SCCWRP), 3535 Harbor Blvd., Suite 110, Costa Mesa, CA, 92626; 4. Division of Biochemistry, School of Medicine, LLU; * Email: TraceyMagrann@Yahoo.com The Four Sites of Upper Newport Bay Upper Newport Bay study sites sorted by genera predominance Introduction Water samples were collected from 42 lakes, ponds, bays, and lagoons from Santa Barbara to San Diego along the Pacific Flyway. Among these were four sites from Upper Newport Bay (Big Canyon Creek pre and post-marsh, Newport Bay, and Newport Valley). All sites were selected based on their variance in nutrient levels and for their ecological importance to wildlife and human recreational activities. Three important water chemistry measurements are nitrogen, phosphorous, and alkalinity. A site with excessive nitrogen and phosphorus is at risk for algal blooms and fish kills. Limiting phosphorous and nitrogen inhibits algal growth. Dissolved phosphorous cannot be mechanically filtered out. However, ferric chloride can be added to the water to bind the phosphorous, causing it to precipitate out of solution. In 2009, a pilot study was performed on Mason Lake (Irvine, CA) using this Blue Pro technology. It was found to reduce algal cells by 94% and decreased phosphate by 96% (Magrann, Dunbar et al. 2009). Cyanophyta are a nuisance algae because they out-compete the healthier green alga as phosphate levels increase, and they can produce toxins (Falconer 2004). Some algal toxins cause liver cancer and neurological damage. Microcystin is one such toxin, produced by Microcystis, the focal organism of this study. Methods Water samples were analyzed for toxin content (by PPIA and LC/MS), biodiversity, and water chemistry values. The latter included pH, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), alkalinity (Alk), chlorophyll-a (Chl-a), total dissolved phosphate (TDP), total dissolved nitrogen (TDN), total phosphorus (TP), total nitrogen (TP), dissolved organic carbon (DOC), ammonium (NH4), phosphate (PO4), nitrite (NO2), nitrate (NO3), dissolved organic phosphorous (DOP), particulate phosphorous (PP), dissolved inorganic nitrogen (DIN), and dissolved organic nitrogen (DON). Results • Toxin Analysis Overall, six sites contained microcystin, cylindrospermopsin, and anatoxin-a toxins in excess of drinking water limits (>1.0 µg·L-1 for microcystin and cylindrospermopsin; > 3.0 µg·L-1 for anatoxin-a; WHO 2001). One of the toxic sites was in Upper Newport Bay (see Table 1). • Water chemistry factors which predict toxin production in excess of drinking water limits Alkalinity, particulate phosphorus, ammonium, dissolved organic nitrogen and phosphorus, and total dissolved nitrogen (see Table 2) • Richness and Evenness were below normal for Newport Bay and Newport Valley However, calculations predict marked improvement with removal of Microcystis (see Fig. 1). • Water chemistry factors affecting algal biodiversity Total dissolved phosphate, phosphate, ammonium, and total phosphate (see Table 3) Blue Pro Pilot Study, Mason Lake, Irvine (2008) Influent water enters the Blue Pro treatment facility (brown trailer), where it is injected with alum, a flocculent that precipitates out most of the algae. The treated water is pumped to the top of one of the sand bed towers and forced down a tube in the center of the tank until it reaches the bottom of the sand bed. Fig. 1. Removal of Microcystis greatly improves richness and evenness Euglena Microcystis Inside the sand bed tower, water is dispersed by horizontal distribution arms, forcing water out of the pipe and into the ionized sand bed which filters out solid particles as water flows toward the top of the tank. Table 1. Toxin levels Cells in orange are above drinking water limits Pandorina Navicula Filtered water returns to the treatment facility to be injected with ferric chloride to precipitate out dissolved phosphate. Water is sent back to the second sand tower for filtration, and clean water is returned to the lake. Table 2. Water Chemistry factors which predict toxin production in excess of drinking water limits Richness refers to the number of individual organisms in the site. A site with normal richness will have a Shannon Index (H’) of 1-4. Evenness refers to the relative abundance or proportion of individuals in the site. A site with ideal evenness will have a Pielou’s Index (J’) of 100%. Biodiversity Explained Richness and Evenness are statistical measures of biodiversity in an ecosystem. A site with normal richness will have a Shannon Index (H’) of 1-4 (Irvine and Murphy 2009). A site with ideal evenness will have a Pielou’s Index (J’) of 100%. Since the study of Magrann et al. (2009) found that Blue Pro filtration was effective in removing Microcystis from aquatic ecosystems, formulas were computed with and without the numbers for Microcystis to assess the benefit of using this technology. Palmellococcus Synuria Results of Pilot Study Discussion All four Upper Newport Bay sites had higher alkalinity than the overall average, and higher than average for toxic sites. We found high alkalinity was the most significant water chemistry factor predicting the presence of microcystin toxins in excess of drinking water limits. Newport Bay and Newport Valley ranked “poor” in richness and evenness, and these parameters would be greatly enhanced by removal of Microcystis by Blue Pro filtration. Table 3. Water chemistry factors affecting algal biodiversity Recommendations • Monitor levels of alkalinity since they were found to have higher values than the average for toxic sites. Use a buffered acid to reduce alkalinity to 180 mg/L CaCO3 or lower. • Removal of Microcystis colonies, phosphorous (TP, PP), and dissolved phosphorous (TDP, DOP, PO4) in Newport Bay and Newport Valley by the use of Blue Pro Technology. Chlamydomonas Ankistrodesmus After treatment with Blue Pro filtration, all large clumps of Microcystis have been removed Mason Lake before treatment: many large clumps of Microcystis References  Falconer, I. R. (2004). Cyanobacterial toxins of drinking water supplies. Oxford, UK, Taylor & Francis, Inc. Irvine, K. N. and Murphy, T. (2009). "Assessment of eutrophication and phytoplankton community impairment in the Buffalo River Area of Concern." J. Great Lakes Res35: 83-93. Magrann, T., Dunbar, S. G. , Sutula, M., Boskovic, D. (2009). Blue Pro Pilot Study at Mason Lake, Irvine, CA. Marine Research Group. Loma Linda. Pg 19. World Health Organization (2001). Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. J. Bartram and I. Chorus, editors. World Health Organization, Geneva. Anabaena Nitzschia