Marine Primary Producers Primary Production
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Marine Primary Producers OCN 201 Biology Lecture 4 http://micro.magnet.fsu.edu/moviegallery/ Photo: Fuhrman Lab; University of Southern California Primary production • Incorporation of new organic matter into cellular material, primarily through photosynthesis (or chemosynthesis) • Rate of phytoplankton production; Rate of production of new phytoplankton biomass • Typically measured as the amount of carbon fixed per unit area (or volume) per unit time • Units (e.g.): g C m-2 yr -1 • Carried out by autotrophs Primary production • On land primary producers are mostly macroscopic • In the sea nearly all primary production is due to microscopic phytoplankton Terrestrial Biomes Primary Producers Dugong feeding on seagrass Photo: Mark Goodchild Kelp Forests Can grow at up to 11 inches/day create habitat structure require cool temperatures, < 20 ºC Kelp Forests Kelp forests are productive Kelp Forests Kelp Forests 100-kilometer range contraction of kelp forests; temperate species replaced by seaweeds, invertebrates, corals, and fishes characteristic of subtropical and tropical waters. (Wernberg et al. 2016) due to narrow temperature tolerance …… susceptible to climate change Macroalgae & Seagrasses Exception: limited to coastal areas Sargassum a planktonic macroalga floating objects aggregate fish Photosynthetic Photosynthetic bacteria picoeukaryotes Dinoflagellate Diatom Most Life in the Sea is Microscopic! Photosynthetic bacteria Photosynthetic picoeukaryotes Dinoflagellate Diatom Most Life in the Sea is Microscopic! Prokaryotic Phytoplankton (Cyanobacteria) Most abundant in the ocean: • Prochlorococcus • Synechococcus (there are others) Responsible for most (~ 80%) of the primary productivity in the open ocean ...and about half of the oxygen on the planet! Discovered by Penny Chisholm Eukaryotic Phytoplankton • Picoeukaryotes (0.2 -2 µm) • Dinoflagellates (5-2000 µm) • Diatoms (2-2000 µm) • Coccolithophores (3 - 50 µm) Picoeukaryotes Ostreococcus - smallest free-living eukaryote François Yves Bouget 0.8 µmin Le Journal du CNRS contains chloroplast, mitochondrion, Golgi body, nucleus a minimal cell Wenche Eikrem and Jahn Throndsen, University of Oslo Prasinophyte Picoeukaryotes Micromonas pusilla nucleus chloroplast flagellated, good swimmer, strongly phototactic is the dominant picoeukaryote in many marine ecosystems mitochondrion Diatom Coccolithophore Silica frustule Calcium carbonate plates Cellulose thecal plates Dinoflagellates Dinoflagellates Harmful algal blooms • Filter feeding shellfish may accumulate algal toxins by feeding on the toxic phytoplankton, sometimes at levels potentially lethal to humans or other consumers • Toxins or other compounds can kill marine fauna directly, or result in low oxygen conditions as the bloom biomass decays 11 Toxic roi kole dinos William Walsh/DAR/DLNR William Walsh/DAR/DLNR Top 10 fish species involved in reported cases of ciguatera fish poisoning in Hawaii during the 5-year period between September 1999 and 2003. RANKING FISH (Hawaiian name OUTBREAKS ILLNESSES and common name) % and (n) % and (n) No. 1 roi 18.5% (23) 22.5% (56) (peacock grouper) No. 2 kole 15.3% (19) 15.7% (39) papio (gold ring surgeonfish) No. 3 ulua 9.6% (12) 7.6% (19) (large jacks mixed spp) No. 4 papio 7.3% (9) 7.2% (18) (small jacks mixed spp) No. 5 seabass 5.6% (7) 8.0% (20) (spp uncertain) No. 6 palani 5.6% (7) 8.0% (20) (eyestripe surgeonfish) No. 7 uku 5.6% (7) 4.8% (12) (green jobfish) No. 8 weke 5.6% (7) 4.8% (12) uku (goatfish) No. 9 wahanui 4.0% (5) 2.8% (7) (smalltoothed jobfish) Benthic dinoflagellate: No. 10 uhu 1.6% (2) 1.2% (3) (parrotfish) Gambierdiscus toxicus TOTAL All fish implicated in 100% (124) 100% (249) reported cases of ciguatera poisoning. palani DIATOMS Fragilaria Navicula pennate or centric DIATOMS Chaetocerous Fragilaria Navicula Coscinodiscus pennate or centric http://bioloc.oce.orst.edu/SherrLab/BESTMG9%20epi%20Chaeto.jpg Siliceous Sediments http://www.marinebio.net/marinescience/02ocean/mgbottom.htm Kaneohe Bay ‘Regular’ community Red is Chlorophyll After storm: Diatom bloom Yellow Dots are Synechococcus Regular community: Dominated by Synechococcus and small eukaryotic phytoplankton After storms (nutrient inputs): Diatom blooms (Selph et al.) Coccolithophores Emiliania huxleyi Coccolithophores Emiliania huxleyi How do we observe phytoplankton ? Fluorometry (Miller & Wheeler 2012) Distribution of phytoplankton HOT 1−268 1200 ) 1 − 1000 d 2 − 800 MeasuringREVIEWS primary production 600 400 a d 0 10 Collect200 seawater, ~5 depths, pre-dawn Primary Production (mg C m 9 14 Spike0 with C 20 8 Depth-integratedDepth89 integrated90 91 92 93 94 95 96 97 98 99 00primary01 02 03 04 05 06 07 08production09 10 11 12 13 14 7 Incubate under in Samplingsitu Dateconditions, all day 40 6 14 HOT 1−268 5 Measure1000 C assimilated into cells 60 ) Depth (m) 4 900 1 5 m − d 3 2 800 − 80 2 25 m 700 1 600 100 0 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 45 m 500 Year 400 b 75 m 300 0 10 200 9 100 m Primary Production (mg C m 100 20 8 0 7 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 125 m 40 6 Sampling Date 5 150 m 60 4 Depth (m) 3 Hawaii Ocean Times series 80 2 1 100 0 80 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month (Gavin Tilstone - PML) c 1000 60 e = 0.20 per d) 2 per d) 2 800 40 600 400 20 200 PC-flux (mg C per m e = 0.01 0 0 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Primary production (mg C per m Primary production 0 400 800 1200 Year Primary production (mg C per m2 per d) Figure 4 | Temporal and depth variability in primary production at Station ALOHA. a | Contour plot of upper water Nature Reviews | Microbiology column (0–100 m) primary production (14C-based; mg C per m3 per day) based on approximately monthly observations throughout a 23 year period. b | Annual production climatology (mg carbon per m3 per day). c | Individual euphotic zone depth-integrated (0–200 m) primary production estimates shown with annual climatology (red line) to show both seasonal and interannual variations. d | The diagram shows the free-drifting primary production and sediment trap arrays that were used to collect the data shown. Particulate carbon (PC) export (sediment traps at 150 m reference depth) versus depth-integrated (0–150 m) primary production with export ratio (e = flux/production) contours of 0.01 and 0.20. slow-growing and to live as chemolithoautotrophs on abundance, metabolism and possible ecological relevance 109–112 Mesopelagic reduced inorganic nitrogen that is ultimately supplied of AOA worldwide, including at Station ALOHA . A term used to describe the to the deep sea via exported particulate and dissolved Archaeal amoA genes are ubiquitous and exceed vertical region of the ocean that matter. The rate-limiting step in nitrification — the bacterial amoA genes, especially in the mesopelagic encompasses the mid-depth (generally ~200–1000 m) oxidation of NH3 — is catalysed by the enzyme ammo- zone (~200–1,000 m). However, the exact role of archaea waters that lie between the nia monooxygenase, which is encoded, in part, by the in the marine carbon and nitrogen cycles is unresolved well-lit euphotic zone and the amoA gene. The discovery of homologous amoA genes and may be site-specific; for example, despite relatively deep bathypelagic waters. The in archaea106,107 from marine metagenomic surveys led to low gene abundances in the upper ocean (<104 cop- mesopelagic waters are the hypothesis that ammonia-oxidizing archaea (AOA) ies per l), transcription of amoA seems to peak at the characterized by vanishingly 108 low light and pronounced may have an important role in nitrification . boundary between the euphotic zone and the mesope- 112 gradients in temperature and In the few years since the discovery of AOA, there lagic zone (~150–175 m) . Such results suggest that the nutrients. has been extensive field investigation of the distribution, lower euphotic zone is a region of active nitrification, NATURE REVIEWS | MICROBIOLOGY VOLUME 12 | OCTOBER 2014 | 707 © 2014 Macmillan Publishers Limited. All rights reserved A Few Key Points • Kelp and sea grasses important in nearshore in nutrient rich areas BUT most primary producers are microscopic • Photosynthetic bacteria (cyanobacteria) are most abundant primary producers on the planet • The larger photosynthetic planktonic eukaryotes are also very abundant • diatoms & coccolithophores have hard shells that create massive (and inspirational) mineral deposits • Chlorophyll a is commonly used as a proxy to quantify phytoplankton abundance in situ Questions?.