Chapter 14 Six Main Concepts  Plankton drift or swim weakly, going where the ocean goes, unable to move consistently against waves or current flow.  Plankton is an artificial category; a category not based on a phylogenetic (evolutionary) relationship but rather on a shared lifestyle.  Phytoplankton are autotrophic, that is, they make their own food, usually by photosynthesis. Plankton productivity depends on largely on light and nutrient availability.  The ocean’s most productive phytoplankters are very small cyanobacteria working in a “microbial loop.”  Zooplankton – drifting animals – consume phytoplankton species (diatoms, dinoflagellates, coccolithophores), forming a food web that eventually supports larger animals like fishes.  Not all producers are drifters. Seaweeds and mangroves are also important contributors.
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Plankton Drift with the Ocean Pelagic organisms live suspended in seawater. They can be divided into two broad groups based on their lifestyle:  The plankton drift or swim weakly, going where the ocean goes, unable to move consistently against waves or current flow.  The nekton are pelagic organisms that actively swim. (RIGHT) The standard plankton net is made of fine mesh and has a mouth up to 1 meter (3.3 feet) in diameter. The net is towed behind a ship for a set distance.
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Plankton Drift with the Ocean Representative plankton and nekton of the pelagic zone in the region of the subtropical Atlantic Ocean. Note the relative magnification of organisms in the plankton community.
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Vent Sea Urchins Key Information: Sea Urchins have been known to feed on algae in other environments, but here it is a decomposer feeding on the detritus of the sea floor Image Source: NOVAE Sea Cucumbers Predators: large fish and crabs Key Information: Feeds on plankton, and scavenge for detritus Image Source: NOVAE Brittle Star Sea Spider Predators: Crabs, fish, and sea stars Key Information: Feeds crustaceans and plankton. But will also scavenge on dead and decaying matter Key Information: Feeds on may creatures, like zoanthids, sea cucumbers, sea anemones, small crustaceans, clams, worms, sea urchins and dead decaying matter Image Source: Interactive Oceans Cockatoo Squid Predators: Does not have any natural predators at the Axial Seamount Vent sites Key Information: feed on fish, crabs, lobsters, and even other squid Image Source: NOVAE Image Source: NOVAE Zoanthids Key Information: mainly feed on plankton and detritus, but can eat worms and small crustaceans Image Source: Smithsonian
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Kingdom Protista .  Kingdom Protista consists of unicellular, multicellular, and colonial eukaryotes, that are in many ways, unlike animals, plants, or fungi (the other eukaryotes).  All protists require some sort of aquatic environment. Protists are found in fresh water and marine environments.  Ecological significance: The protists can exist in great numbers in aquatic systems and are an important part of the plankton. The plankton forms the base of aquatic food chains. Some protozoans are important decomposers in living systems. 
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Chapter 14 Study Plan  Plankton Drift with the Ocean  Plankton Collection Methods Depend on the Organism’s Size  Most Phytoplankton Are Photosynthetic Autotrophs  Measuring Primary Productivity  Lack of Nutrients and Light Can Limit Primary Productivity  Production Equals Consumption at the Compensation Depth  Phytoplankton Productivity Varies with Local Conditions  Zooplankton Consume Primary Producers  Seaweeds and Marine Plants Are Diverse and Effective
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Plankton Drift with the Ocean • Autotrophic plankton that generate glucose by photosynthesis, the primary producers, are generally called phytoplankton. • Phytoplankton are critical to all life on Earth because of their great contribution to food webs and their generation of large amounts of atmospheric oxygen through photosynthesis. • Planktonic autotrophs are thought to bind at least 50 trillion kilograms of carbon into carbohydrates each year, roughly 50% of the food made by photosynthesis on Earth!
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Most Phytoplankton Are Photosynthetic Autotrophs Major types of phytoplankton? • Picoplankton – this category encompasses most other plankton types, which are very small. • Diatoms – the dominant and most productive of the photosynthetic plankton. • Dinoflagellates – widely distributed singlecelled phytoplankton; use flagella to move. • Coccolithophores – small single-celled autotrophs.
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Zooplankton Consume Primary Producers Heterotrophic plankton are collectively called zooplankton. The mass of zooplankton is typically about 10% that of phytoplankton. Most zooplankton spend their whole lives in the plankton community, so we call them holoplankton. (TOP RIGHT) Copepod. Some planktonic animals are the juvenile stages of crabs, barnacles, clams, sea stars, and other organisms that will later adopt a benthic or nektonic lifestyle. They are known as meroplankton. (BOTTOM RIGHT) Larval sea urchin.
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XIII. Productivity and Energy Transfer: Chapter 13 by Al Trujillo Plankton net Topics: A. Photosynthesis and Respiration B. Marine Food Webs C. Productivity D. Regional Oceanic Plankton sample
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XIII. Productivity and Energy Transfer: Chapter 13 End Plankton sample Plankton net Ocean chlorophyll
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Homework. A patch of plankton embedded in the flow field is found to in one day to diffuse horizontally 10 km over and vertically 5 m. Estimate the vertical and horizontal diffusivities. Estimate the characteristic velocity and space scales. What can you say about the motility velocity of the plankton? How much further would they diffuse horizontally and vertically in two days? 2 2 3.6 2 2 145
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Fish - Planktivores Fish that depend on zooplankton as their major food source are called planktivores. Plankton = free-floating plants and animals These fish filter or strain zooplankton from the water using comb-like structures called gill rakers. Particles trapped by the gill rakers become more concentrated as they move further into the mouth and the fish finally swallows a soup of plankton. http://www.nature.com/nature/journal/v412/n6845/fi g_tab/412387a0_F1.html http://pond.dnr.cornell.edu/nyfish/Salmonidae/cisco.html The lake herring is a common planktivore in Lake Superior and is a major food source for lake trout. Lake herring are often smoked and sold in fish shops around the lake. ‘vore’ = eat
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Kristen Lycett, M.S. Student, MEES Ecology AOS, performing a plankton trawl for dinoflagellates, advisor: Dr. Joe Pitula.
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TURBIDITY • Turbidity: measure of relative sample clarity • Increases with TSS (or SPM) • Soil particles, algae, plankton, microbes, other debris • Size range of 0.004 mm (clay) to 1.0 mm (sand) • Affects how much light is scattered • Increased turbidity = Increased scattering of light • Can affect water color
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Epitokes   14 Epitoky – Theses are given the task of reproduction – Some individuals bud epitokes from the body and remain in the habitat Some species lack a freeswimming or plankton stage, and are produced in protective gelatinous egg masses Phylum Annelida
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Inquiry 1. What is the difference between nekton and plankton? 2. Describe the krill fishery. 3. Why did the krill catch drop in 1984 and 1993? 4. What is a drift net?
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Currents Oceanic conveyor belt may change ocean currents • Currents carry plankton • Bring food and oxygen • Distribute eggs and larvae • Remove wastes and pollutants
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Acidity • CO2 makes water acidic • Corals and other calcium carbonate species can’t make skeleton • Impact on plankton development impacts food web
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Consequences of Ocean Acidity Animals with CaCO3 skeletons affected • Plankton • Corals • Mollusks • Fish Fisheries http://news.bbc.co.uk/2/hi/science/nature/7933589.stm
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Oxygen Isotope Analysis • During colder weather, more light 16O evaporates, leaving ocean water with more heavy 18O. • This oxygen is incorporated into coral, plankton shells and sediments at the ocean bottom. • In colder climates, these proxy indicators will be enriched in 18 O. • The ratio of 18O to 16O, (δ 18O) can be correlated to temperature. For benthic (deep-water sediments), colder temperatures are related to higher values of δ 18O.
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Chapter 14: Primary Productivity Plankton, Plants and Algae
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Most Phytoplankton Are Photosynthetic Autotrophs      Diatoms Apart from cyanobacteria, the most productive photosynthetic organisms in the plankton are the diatoms. Diatoms have transparent silica frustules that allow for both protection and light penetration into the cell. Diatoms store energy as fatty acids and oils, compounds that are lighter than their equivalent volume of water and assist in flotation. When diatoms die, their valves fall to the seafloor to accumulate as layers of siliceous ooze. (RIGHT) Photographs of various diatoms.
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Phytoplankton Productivity Varies with Local Conditions Variation in oceanic primary productivity by season and latitude. (a) In the tropics, an intense thermocline prevents nutrient-rich water from rising to the surface. Productivity is low throughout the year. (b) In the northern temperate ocean, nutrients rising to the surface combine with spring and summer sunlight to stimulate a plankton bloom. (c) In the northern polar ocean, a high and thin productivity spike occurs when the sun reaches high enough above the horizon to allow light to penetrate the ocean surface.
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Internal Waves Can Form between Ocean Layers of Differing Densities Subsurface waves that form at the boundary between water layers of different densities are called internal waves. • • • Internal waves occur in the ocean at the base of the pycnocline, especially at the bottom edge of a steep thermocline. Internal waves are generated by wind energy, tidal energy, and ocean currents. They may mix nutrients into surface water and trigger plankton blooms.
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Measuring climate change • Oxygen isotopes in marine fossils – When earth’s average temperatures are lower, more 18O remains in the water. – Coral take in seawater to make their exoskeleton. – Therefore in coral and plankton a higher 18/16 ratio indicates lower average temperatures.
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Using δ O18 ratios in coral to measure ocean temperatures • Oxygen isotopes in coral – When earth’s average temperatures are lower, more 18O remains in the water – Coral take in seawater to make their exoskeleton – Therefore in coral and plankton a higher 18/16 ratio indicates lower average temperatures
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Measuring climate change • Plankton and isotopes in ocean sediment – Shells and other “hard parts” preserved in marine rocks / muds give two lines of information • What was alive at the time gives climate information • 16/18O ratios in biogenic carbonate • Rock and fossil record – fossils give much information, what lived when – Rock records formative environment
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• Estimation of turbidity of water using senchi disc • Turbidity is a function of suspended plankton growth and amount particulate matter in water
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Krill • Component of plankton • Major food for whales 70
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Guiding Questions • How did plankton in the ocean become more modern during the Cretaceous Period? • How did the evolutionary expansion of predatory taxa transform the marine ecosystem during Cretaceous time? • How did reef ecosystems change during the Cretaceous Period? • How did terrestrial floras change during the Cretaceous Period? • What happened to Gondwanaland during the Cretaceous Period?
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Life of the Cretaceous • Plankton – Diatoms radiated – Foraminifera diversified – Calcareous nannoplankton radiated – Ammonoids and belemnoids persisted
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Marine Realm • Photic Zone – Region of ocean where enough light penetrates to permit photosynthesis • Pelagic life – Plankton • Phytoplankton • Zooplankton – Nekton • Benthic life – Suspension feeders – Deposit feeders 36
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