Chapter 14: Primary Producers

Chapter 14: Primary Producers Ernst Haeckel diatoms Diatom drawings by Ernst Haeckel Diatom art under a microscope slide 1

Images from Puget Sound: M. Guannel/H. van Tol 2

Images from Puget Sound: M. Guannel/H. van Tol 3

Outline for Final Weeks 4/11: Primary Producers (Chapter 14) 4/13: Marine Animals (Chapter 15) (and voluntary class evaluation) 4/18: Marine Communities (Chapter 16) Coral reefs, hydrothermal vents, rocky intertidal 4/20: Ocean Challenges (Chapters 17 & 18) Climate change, sea level rise, marine debris 4/25: Review session for final exam 4/27: Final Exam 4

Chlorophyll and net primary productivity NASA animations http://earthobservatory.nasa.gov/globalmaps/view.php?d1= MY1DMM_CHLORA&d2=MOD17A2_M_PSN In-Class Activity: Observe the animation. 1. What do you see? 2. Why do you think this is important to oceanography? 5

Take one breath. Then take a second breath. 6

Thank phytoplankton for your second breath. 7

Learning Goals: Primary Productivity Primary productivity: carbon is made through photosynthesis or chemosynthesis. Life in the ocean (mostly microscopic) is responsible for producing half of the oxygen on Earth. Most primary producers are plankton: diatoms, coccolithophores, dinoflagellates, cyanobacteria (to name a few) Some primary producers are benthic organisms: Seaweed (macroalgae), sea grasses, mangroves Phytoplankton are generally beneficial parts of marine ecosystems, but sometimes cause harmful algal blooms and (indirectly) dead zones. Microorganisms play important roles in biogeochemical cycling. Much of this cycling happens within the microbial loop. The middle latitudes are generally the most biologically productive, although tropical waters have important hotspots of productivity. Note: Coral reefs and hydrothermal vent communities: Monday, 4/18 8

Three categories of marine organisms, defined by habitat and movement. Plankton wanderers Nekton swimmers Phytoplankton (plant like) autotrophs in photic zone. What is the third major category of marine organisms, as defined by habitat? 9

Three categories of marine organisms, defined by habitat and movement. Plankton wanderers Nekton swimmers Phytoplankton (plant like) autotrophs in photic zone. What is the third major category of marine organisms, as defined by habitat? Benthos 10

Plankton, Nekton, or Benthos? http://www.gizmag.com/ jellyfish-bloomdirection/35964/ See video of jelly being tagged Professor Graeme Hays, from Deakin and scientists from Swansea University, tracked free-ranging barrel-jellyfish in waters off northern France using GPS loggers equipped with accelerometers that allowed the scientists to observe how the jellyfish orientate their movements with respect to currents. GPS-tracked floats were used to record the local currents. The GPS data showed they were actively swimming counter to the current and the researchers are now asking whether this occurs with other species of jellyfish? 11

Photosynthesis Chlorophyll a is the main light-harvesting pigment. However, other accessory pigments are found in different photosynthesizing organisms. These other pigments are specialized to absorb different wavelengths of light. 12

Marine Flowering Plants Only in shallow coastal waters Primarily grasses and mangroves 13

Macroscopic Algae Brown, green, and red algae Sargassum 14

Kelp can grow up to 20 inches /day. 15

Microscopic algae (phytoplankton) cover a wide range of sizes. Finkel et al. 2010 16

Microscopic Algae Produce food for 99% of marine animals Most planktonic Golden algae Diatoms tests (shells) made of silica, accumulated shells produce diatomaceous earth Coccolithophores plates of calcium carbonate Approximately 100,000 species of diatoms alone! (not just in marine habitats) 17

The diatom Pseudo-nitzschia forms Harmful Algal Blooms (HABs). 37 species 14 (?) produce domoic acid (DA) Primarily coastal small big razor clams, other shellfish NOAA anchovies, sardines WDFW humans: Amnesic Shellfish Poisoning (ASP) sea lions the birds Seattle Times Marine Mammal Center USFWS 18

Microscopic Algae Dinoflagellates Red tide (harmful algal bloom) Toxins Fish kills Human illness 19

Harmful Algal Blooms Natural conditions may stimulate dinoflagellate productivity. Some produce toxins inadvertently consumed by fish and shellfish. Humans who eat affected fish may get Paralytic Shellfish Poisoning (PSP). 20

21

Karenia brevis causes most Florida HABs. http://myfwc.com/research/redtide/faq/ Why are red tides harmful? Many red tides produce toxic chemicals that can affect both marine organisms and humans. The Florida red tide organism, K. brevis, produces brevetoxins that can affect the central nervous system of fish and other vertebrates, causing these animals to die. Wave action can break open K. brevis cells and release these toxins into the air, leading to respiratory irritation. For people with severe or chronic respiratory conditions, such as emphysema or asthma, red tide can cause serious illness. The red tide toxins can also accumulate in molluscan filter-feeders such as oysters and clams, which can lead to Neurotoxic Shellfish Poisoning in people who consume contaminated shellfish. 22

Ocean Eutrophication & Dead Zones 23

Gulf of Mexico Dead Zone Second largest in world 22,000 sq. km (8500 sq. mi) Runoff of nutrients, esp. nitrates Algal blooms 24

Dead zones are frequently found near high populations of humans. 25

http://www.tcpalm.com/opinion/guest-columns/richard-baker-indian-river- lagoon-may-be-close-to-becoming-a-dead-zone-2e03ca8e-2862-50e9-e053-01000-374618771.html 26

Photosynthetic bacteria Prochlorococcus is so far the most abundant photosynthetic organism on Earth (an estimated 10 27 cells total) Prochlorococcus This genus alone carries out 10-20% of all photosynthesis in the ocean and yet it was only discovered in 1985. Prochlorococcus is a genus that is a type of picoplankton extremely small and very abundant. 100 million cells in every liter of seawater. 27

Prochlorococcus was discovered by Dr. Sallie (Penny) Chisholm of MIT and her postdoctoral researcher, Dr. Rob Olson, in 1985. She was awarded the National Medal of Science (nation s highest award in science and engineering) in 2013. OCE1001 Dr. Chisholm Dr. Rocap Dr. Guannel http://www.ascb.org/sallie-penny-chisholm-tiny-cell-with-global-impact/ 28

Microscopic algae (phytoplankton) cover a wide range of sizes. Finkel et al. 2010 29

Diatoms most productive autotroph. Increased oxygen 100 mya. Silicate shells. Contains accessory pigments to absorb more colors (including green). 30

A closer view using a scanning electron microscope shows the perforations in detail. Each is small enough to exclude bacteria and some marine viruses. The holes in this diatom (Thalassiosira) allow it to pass gases, nutrients, and waste products through the otherwise impermeable silica covering. This diatom is surrounded by a wreath of coccoliths (Reticulofenestra) in what may represent a symbiotic relationship. 31

Ditylum Coscinodiscus 32

Diatoms (single-cell) reproduce asexually by division. When they get small enough, they reproduce sexually. Diatoms eventually sink forming siliceous oozes. 33

34

Appear milky-white. 35

White cliffs of Dover 36

Nutrient Flow in Marine Ecosystems Detritus dead remains and waste products Biogeochemical cycles chemical parts of matter cycled through ecosystem 37

The microbial loop recycles nutrients among microorganisms, the sediments, etc. 38

Finkel et al. 2010 39

Matter that is not recycled within the microbial loop gets transferred up to higher trophic levels. 40

Productivity varies depending on location. 41

Productivity in Tropical Oceans 42

Polar Ocean Productivity Winter darkness Summer sunlight Phytoplankton (diatoms) bloom Zooplankton (mainly small crustaceans) productivity follows Example: Arctic Ocean s Barents Sea 43

Temperate Ocean Seasonal Cycle 44