Transcript Slide 1
Biogeochemical Cycles • Carbon and Nitrogen LIFE • Living things contain matter in a highly organized, low-entropy state; they can capture, store, and transmit energy. • Organisms are also capable of reproduction and change through time. The Biological Pump • The biological pump is the process by which CO2 fixed in photosynthesis is transferred to the ocean interior resulting in a temporary or permanent storage of carbon. • This biogeochemical process involving plants, the animals that consume them, and the bacteria that assimilate their waste plays a central role in the global carbon cycle. Biogeochemical Cycles • Natural processes that recycle nutrients in various chemical forms from the nonliving environment to living organisms and then back to the nonliving environment Chemicals used by organisms • Organisms use chemicals in their metabolism • Carbon • Oxygen • Hydrogen • Nitrogen (proteins, nucleic acids) CARBON • The basic building block of life • Carbon enters the atmosphere though; respiration volcanic eruptions release from rocks deep in earth’s crust burning of fossil fuels Photosynthesis • Carbon dioxide is removed from the atmosphere by producers that use CO2, sunlight and nutrients to make food through the process of photosynthesis. • Plants FIX carbon into usable forms (sugar) CO2 Photosynthesis Phytoplankton Respiration • Some CO2 is then released back into the water through respiration as the plankton break down their food to release energy. CO2 Photosynthesis Respiration Phytoplankton Consumption • Some of the carbon is passed on to primary consumers: zooplankton (animal plankton) and other filter feeders that depend on phytoplankton for their energy. CO2 Photosynthesis Respiration Phytoplankton Zooplankton Consumption Decomposition • Bacteria play a vital role in the biological pump by decomposing organic particles such as waste products and dead organisms that sink to the deep sea (Aerobic decomposition releases CO2). Microbial Loop • Dissolved organic carbon (DOC) is used by • • • • • • bacteria Bacteria is eaten by protozoan Protozoan are eaten by zooplankton Zooplankton is eaten by fish Fish excrete DOC DOC is eaten by bacteria And so on… CO2 Photosynthesis Respiration Phytoplankton Zooplankton Decomposition Consumption Bacteria Higher Trophic Levels • Consumption continues to transport carbon through higher trophic levels. CO2 Respiration Respiration Photosynthesis CO2 Phytoplankton Zooplankton Decomposition Consumption Higher Level Consumers Consumption Decomposition Bacteria Higher Trophic Levels • The process continues… CO2 Respiration Phytoplankton Zooplankton Decomposition Consumption Higher Level Consumers Consumption Decomposition Bacteria CO2 Respiration Respiration Photosynthesis CO2 Nitrogen • Critical component of proteins, chlorophyll and nucleic acids • Found in the bodies of organisms in different forms… Nitrogen input • Nitrogen is added to the ocean by; river runoff precipitation nitrogen-fixing organisms Useable nitrogen • 48% of dissolved gas in seawater is nitrogen • Organisms can not use free nitrogen • Must be bound to oxygen or hydrogen • Bacteria fix nitrogen (make it bigger) • Plant growth is limited because of the limited source of useable nitrogen Nitrogen and animals • As dissolved organic ions (waste): ammonium NH4+ nitrite NO2nitrate NO3- Nitrogen and plants • Small oceanic plants use mostly nitrate (fertilizer) • Fish eat the plants and excrete ammonia and urea. • Mulm the technical term for what comes out of the vent • Then bacteria fixes the mulm into useable fertilizer for plants again In an aquarium • Ammonia is in fish waste and is also released through gills when they absorb oxygen (breathe) • Ammonia can be changed into a toxic form called Ammonium depending on pH levels, temperature, and salinity • High levels of ammonium can kill fish 3 KINDS OF FILTRATION USED TO GET RID OF WASTE BIOLOGICAL: Bacteria ingest waste and convert it. CHEMICAL: O3 binds to “junk” in the water and makes it easier to remove. Carbon also removes impurities from the water. PHYSICAL: Water flows through mechanical filter plates and the waste gets trapped. Micron filter and cotton filter Ozone generator and carbon filter Nitrifying Bacteria • Nitrobacter and nitrosomonas (the good kind of bacteria) • Converts ammonia and nitrites into nitrates • Denitrifying bacteria turns nitrates back into nitrites and free ammonia • This keeps the cycle going Nitrosomonas europaea Where the bacteria lives • On any clean, hard surface • Aerobic NEED oxygen • Examples: gravel bioballs filter plates Problems with Aquariums • Temperature • Bacteria populations • Parasites • Stress Parasites • Worms; Nematodes (round worms) Trematodes (hooks and suckers) Nematodes found in gut (usually) Trematodes found in gills or on outside of body. Little parasites… • Ciliated Protozoans; Ichthyopthirius multifiliis (ICH) fresh Cryptocaryon (crypt) salt ICH and CRYPT • Appears as white spots anywhere on a fish • Fish will rub against rocks etc. because its itchy • Very contagious • Spreads rapidly • Is always present but will “take over” if a fish’s immune system is suppressed by; stress, sudden change in temp, etc. Ichthyopthirius multifiliis (ICH) Cryptocaryon (crypt) Treatments (FYI) • If you are treating Ich use a salt water bath • If you are treating crypt use a fresh water bath • If your tank has NO invertebrates you can use a copper solution (but they can build a tolerance to this over time)