Plankton Species Diversity and Abundance A Comparative Study in San Francisco Bay and the Greater Farallones National Marine Sanctuary Fadwa Bouhedda, Viktoria Kuehn, John Damascus, Gretchen Coffman, PhD Introduction Methods Results (continued) The plankton community of oceans and estuaries is comprised of •Sampling Locations: Plankton tows were performed at three estuarine sites Abiotic water quality results are depicted in Table 1. The two all aquatic organisms that are free-floating and carried by (Point Bonita, Shipping Channel, and Clipper Yacht Harbor) and two upwelling estuarine samples, had lower wind speeds at 0.6 m/s and 1.1 m/s, a current. Organisms classified as plankton thus range in size and marine sites (Farallon Islands West and East). lower pH (7.95 and 7.87) and lower visibility (2.25m and 1.45) respectively. Compared to the ocean samples, estuarine sites had variety, from unicellular diatoms to large jellyfish. Plankton can be •Plankton Net Tow: A 325-µm mesh plankton net was towed at 2 knots for 10 higher temperatures (16.0-17.2 °C), lower salinity (30.3-30.5 ppt), broadly divided into phytoplankton (producers) and zooplankton minutes along the surface of the water. The net was deployed at the stern of the (consumers). The University of San Francisco is conducting a 30 and slightly lower levels of dissolved oxygen (9.06-9.70 mg/L). The boat, and contents were immediately fixed with a solution of 50% aqueous ocean sites had wind speeds of 4.2 and 6.1m/sec, a more basic pH of year study of species diversity and abundance comparing plankton propylene glycol and 1% formaldehyde. The jars were then sealed and analyzed in a communities of the San Francisco Bay estuary with those of the 8.10 and 8.14, and greater visibility (5.78 and 8.75). Ocean water laboratory at University of San Francisco with Leica light microscopes. samples compared to Bay samples had lower water temperatures Pacific Ocean within the Greater Farallones National Marine The number of cubic meters of water sampled per site was calculated based on: (14.5-15.6 °C), more saline water (31.4-31.8ppt), and slightly higher Sanctuary (GFNMS). The southern edge of the GFNMS is bordered dissolved oxygen levels (9.63-10.10 mg/L). by the Monterey Bay National Marine Sanctuary, which protect the 푉표푙푢푚푒 = ᴨ푟2퐿 coastline from Marin County towards Monterey Bay. There is a Where length of tow: Table 1. Abiotic and water quality measurements along a transect from San Francisco Bay at Fisherman's Wharf to 푚 continental shelf October 2015. ~200 square mile gap in protection from Point Bonita to Pacifica, in Tide Air Wind Depth Water Salini Conduc- Sec 퐿 = 푡 Site DO DO Time Heigh Long/Lat Temp. Speed Sample Temp. ty tivity pH chi which samples were collected (Karl et al., 2001). Data were collected ℎ푟 Sampled (mg/L) (%) •Abiotic Factors: GPS coordinates and time were measured with an eTrex GPS. t (m) (°C) (m/sec) d (m) (°C) (ppt) (mS/cm) (m) along transects on boat expeditions in 2012, 2013, and 2015 as part N 1 16.2 30.4 38.8 9.70 97.8 Point 37°49’14.2” Air temperature and wind speed were measured with a Kestrel 4500 Pocket 9:00 0.54 13.4 0.6 7.95 2.25 of the USF California Ecosystems course. It was hypothesized that Bonita W122°30’29. 5 16.0 30.5 38.6 9.47 95.6 Weather Meter. Water temperature, conductivity, salinity, dissolved oxygen, and 1” higher abundance and species diversity of plankton would be found Fisherman N 1 15.6 31.5 39.8 10.10 101.4 ’s Cove 37°42’0.02” pH data were measured with a Hach HQ40d portable multiparameter meter with 12:24 1.82 13.5 4.2 8.10 5.78 in samples from the Ocean compared to Bay samples. To test this Farallones W122°59’53. 5 15.3 31.8 39.6 10.09 100.9 hypothesis, plankton tows were conducted at two estuarine and two three different probes (conductivity, dissolved oxygen, and pH). Salinity was also West 3” Mirounga N 1 15.0 31.4 39.2 9.82 98.6 determined with a Reichert Goldberg Salinity Refractometer. A Secchi disc was Bay 37°41’40.5” ocean sites along a 30 mile transect (see Figure 2). Abiotic factors 13:20 1.31 13.2 6.1 8.14 8.75 (Farallone W123°00’52. 5 14.5 31.8 39.0 9.63 95.8 were also surveyed at sampling locations for correlation purposes. used to sample water clarity. s East) 8” N Clipper 1 17.2 30.3 39.8 9.22 95.6 37°48’29.3” Yacht 16:55 0.48 19.3 1.1 7.87 1.45 W122°25’1.9 5 17.1 30.3 39.6 9.06 93.9 Harbor Results ” Various plankton were observed from collected water samples at Sites 1-4 (Fig.6). Figure 1 shows specific organisms observed and identified. A total of 71 Discussion and Management species of phytoplankton and 27 species of zooplanktons were found. Among the Our data reveal some key features about plankton communities in the plankton observed are dinoflagellates, diatoms, larval stages of arthropods, GFNMS near the Farallon Islands compared to the San Francisco Bay A B macroalgae, copepods, copepod nauplii, and amphipods. estuary. The data in Figures 3 and 4 indicate that lower trophic levels USF students identified and analyzed plankton individuals from ocean and have a greater number of individuals at both locations. Phytoplankton, estuarine water samples collected in October of 2012, 2013 and 2015. The data in as primary producers, must be more abundant than consumers at the Figures 3 and 4 indicate there is a higher abundance of plankton in the ocean than next trophic level. The greater abundance of phytoplankton at the ocean in the estuary. Plankton species diversity was highest 28 miles offshore, near the locations than the estuary locations may be due to upwelling nutrients Farallones Islands, and lowest in the estuary. that concentrate around the Farallones (Anderson and Lucas 2008). Data in Figure 6 indicate that plankton species diversity vary across time C D and location, which may be linked to seasonal weather changes, nutrient fluctuation, and grazing zooplankton communities. Figure 1. Various plankton identified at 40x magnification from tows in 2015 and 2016. Pictured are (A) Dinoflagellates- Estuary Ocean Phylum: Dinophyta - ceratium; (B) Chrysophyta- coscinodiscus (C) Skeletonema sp. (D). Coscinodiscus sp. (Photos by USG authors) While much of the North Central California coast has been protected as Marine Protected Areas (19.97%, 152.41 km2) and three large areas as Study Location National Marine Sanctuaries, very little of the San Francisco Bay has been designated as protected areas (PISCO 2007). However, estuarine ecosystems are vital to many marine organisms, especially juveniles. In the San Francisco Bay estuary alone, more than 90% of the tidal marshes that once lined the estuary’s shores have been altered and nearly half of the water that once fed the estuary has been diverted (Cohn 2000). 3 Figure 3. Abundance of phytoplankton and zooplankton (number/m ) Figure 4. Abundance of phytoplankton and zooplankton between Creating reserves within this critically stressed environment is crucial. for Bay sites (Point Bonita and the Shipping Channel) compared to San Francisco Bay and Ocean sites (number of plankton per m3 of ocean sites (West Side and East Side of the Farallones) sampled in ocean water) from data collected by USF students in 2015. Understanding variability in plankton abundance and diversity over 2015. the long-term will provide insight to future interannual predictions of ecosystem productivity. We hope our collective results from this project will inform the GFNMS management to help ensure our coast will protect marine life diversity and abundance, restore depleted populations, and ensure the integrity of the ecosystem. Citations • Anderson, T.R. and M.I. Lucas. 2008. Upwelling Ecosystems. Pages 450 – 460 in S.E. Jørgensen, editor. Ecosystem Ecology. Elsevier, Amsterdam, North Holland, The Netherlands. • Cohen, A. 2000. An Introduction to the San Francisco Estuary. San Francisco Estuary Institute, San Francisco Estuary Project, and Save the Bay, A B Oakland and Richmond, California, United States. • Karl, H.A., J.L. Chin, E. Ueber, P.H. Stauffer, and J.W. Hendley II. 2001. Beyond the Golden Gate – Oceanography, Geology, Biology, and Environmental Issues in the Gulf of the Farallones. U.S. Department of the Interior, U.S. Geological Survey, Reston, Virginia, USA. Figure 2. The route taken and sampling locations from the 2015 data collection. This route began and ended in the Figure 5. Sampling methods of (A) Secchi disk and (B) plankton Figure 6. Number of plankton species observed in the Estuary, • Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO). 2007. The Science of Marine Reserves (2nd Edition, United States Version). Clipper Yacht Harbor, Sausalito. net tow taken in duration of Farallon Islands transect, 2015. Ocean and along the continental shelf in 2012 and 2013 samples. www.piscoweb.org. 22 pages..