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Marine Biology - Exam 1 (BSC-3312)
Global Ocean - โ๏ธ Interconnected basin of seawater divided into 5 regional oceans 5 regional oceans - โ๏ธ Pacific, Atlantic, Indian, Southern, Arctic Seas - โ๏ธ Marginal Areas to oceans, surrounded by land Continental Shelf - โ๏ธ Shallow, gently slowing extension of continental land mass Extends off shore to depths of 100m Continental Slope - โ๏ธ Outer edge where shelf drops off rapidly Extends to depths of 2-3 km Continental Rise - โ๏ธ Final area of continental slope before it levels out Order of land - โ๏ธ continental shelf, continental slope, continental rise, abyssal plain Abyssal Plain - โ๏ธ Flattened area beyond the continental slope 3-5km depth 76% of ocean floor Mid-ocean ridges - โ๏ธ Underwater mountain chains created by volcanic activity What causes mid-ocean ridges - โ๏ธ volcanic activity Trenches - โ๏ธ Where abyssal plains cut by deep, narrow canyons 3-4 km deeper than ocean floor Seamounts - โ๏ธ Extinct volcanoes Don't reach surface Occur in clusters around mid-ocean ridges Proximity to Land - โ๏ธ Neritic Providence, Oceanic Providence, Pelagic, Benthic Depth of ocean -
โ๏ธ Intertidal, Bathyl (midnight), Abyssal, Hadal (trench) Photic Zone - โ๏ธ Surface layer to 200m, Photosynthesis occurs Aphotic Zone - โ๏ธ Below 200m, little to no light Dysphotic - โ๏ธ Twilight Zone around 1000m Not enough light for photosynthesis Thermocline - โ๏ธ Zone of rapid temperature transition, separates warmer surface water from cooler, deeper water Thermocline in Tropics - โ๏ธ Strong, permanent thermocline Thermocline in temperate waters - โ๏ธ Seasonal thermocline established in summer, breaks down in fall/winter Thermocline in Polar Waters - โ๏ธ Lack thermocline Salinity - โ๏ธ Total salt dissolved in seawater, averages 3.5% Salinity meters measure the __________ of the water - โ๏ธ conductivity Amount of oxygen is _____ in seawater vs. air - โ๏ธ less Colder water holds ____ oxygen than warmer water - โ๏ธ more Oxygen minimum zone - โ๏ธ Oxygen levels rapidly decrease, very low levels found around 200-1000m Below oxygen minimum zone, oxygen ________ - โ๏ธ increases Ocean acidification occurs when seawater falls below pH ________ - โ๏ธ 7. Ocean currents can be generated by - โ๏ธ Winds (gyres) and temperature/salinity differences (thermocline circulation) North Atlantic Gyre -
Half organic half inorganic Diatoms - โ๏ธ Unicellular algae enclosed by cell walls made of silica (SiO2) Blooms - โ๏ธ Diatoms Occur when environmental conditions are favorable (lights and nutrients) Amnesic Shellfish Poisoning - โ๏ธ Serious neurological condition seen in humans when consumed high concentrations of domoic acid A biotoxin produced by diatoms Dinoflagellates - โ๏ธ Planktonic, unicellular Posses 2 flagella for locomotion Both photosynthetic and heterotrophic Produce luminescence Harmful Algal Blooms - โ๏ธ Dinoflagellates produce neurotoxins that accumulate in shellfish causing health issues Zooxanthellae - โ๏ธ Dinoflagellates Have symbiotic relationship with coral Coccolithophores - โ๏ธ Unicellular and very small Ex: Fossilized coccoliths form white cliffs of dover Nitrogen fixating bacteria - โ๏ธ provide N source to other marine organisms Nitrogen Fixation - โ๏ธ Convert N2 to Ammonia (NH3) Nitrification - โ๏ธ Conversion of NH4+ to nitrite (NO2-) or nitrate (NO3-) by other bacteria Vertical mixing can be blocked by the - โ๏ธ thermocline High Nutrient Low Chlorophyll (HNLC) - โ๏ธ Low levels of primary production even if plenty of nitrogen Iron is limited Geo Engineering - โ๏ธ Hypothesis that seeding the ocean with more Fe will increase primary production, create carbon sink, lowering levels of carbon dioxide in atmosphere and help global climate change
Polar Primary production patterns - โ๏ธ Very seasonal Winter-light limiting Summer: nutrient limiting Tropics Primary prod. patterns - โ๏ธ No vertical mixing (permanent thermocline) Lots of light, nutrient limiting Spring Bloom - โ๏ธ Enough light and vertical mixing so nutrients are not limited Temperate Prim. Prod Summer - โ๏ธ Dip as nutrients become limiting Fall Bloom - โ๏ธ If enough light still and mixing begins so nutrients are not limited Upwelling - โ๏ธ Winds blowing parallel to coast cause surface waters displacement Causes higher primary productivity on western coasts of continents Microbial Loop - โ๏ธ Organic compounds, Bacteria, Viruses El Nino - โ๏ธ Trade winds diminish along warmer nutrient poor waters to displace upwelling along western coast Decrease phytoplankton La Nina - โ๏ธ Have trade winds and upwelling occurs Kelp Communities - โ๏ธ Very large brown algae in cool temperate nutrient rich water (western coasts) Seagrasses - โ๏ธ Only true marine angiosperm Rhizome - โ๏ธ Horizontal stem called that grow under the sediment Littoral Zone (Intertidal) - โ๏ธ Habitat in narrow area along shoreline between high and low tide marks Stressful for organisms: used recreationally by humans Emersion - โ๏ธ Exposed to air and out of water Epifauna - โ๏ธ Organisms in rocky shore communities that live on rock surface
โ๏ธ Anaerobic bacteria dominate, produce H2S Bioturbators: infauna that use siphons to bring oxygen rich water into sediment Zonation (beach) - โ๏ธ Upper: Amphipods and isopods, ghost and fiddler crabs Lower: Tiny worms, clams Wrack Communities - โ๏ธ Mini "ecosystems" along beach, washed up from waves Outwelling - โ๏ธ Movement of materials and nutrients from estuaries out into ocean Estuaries - โ๏ธ High primary production Low diversity/ High biomass Salt Wedge - โ๏ธ Higher salinity water sinks to the bottom Tide moves salinity back and forth (exposes organisms to range of salinity) Euryhaline - โ๏ธ Tolerate wide range of salinities Stenohaline - โ๏ธ Tolerate narrow range of salinties Osmoconformers - โ๏ธ Allow body salinity to change with environemnt Partial Osmoregulators - โ๏ธ Isotonic in seawater (osmoconform.), hypertonic (osmoreg.) when in more fresh water Ex: Crustaceans Osmoregulators - โ๏ธ Keeps body salinity constant Rid excess water or absorb more salt by active transport using gills or kidneys Ex: Fish Saltmarshes (Tidal Marshes) - โ๏ธ Flooded at high tide Muddy bottom, dominated by salt tolerant plants Mudflats - โ๏ธ Exposed at low tide Desiccation at low tide Diatoms provide primary production Lots of bacteria produce H2S Most animals are infauna Natural and Artificial Estuaries -
โ๏ธ Filter and purify waste water before entering ocean Red mangrove - โ๏ธ Most salt tolerant and found closest to shoreline White Mangrove - โ๏ธ Least salt tolerant and furthest inland Arctic Physical Characteristics - โ๏ธ Relatively small, isolated body of water Extensive shallow continental shelf 2 outlets:
- Bering Strait to Pacific
- Fra Upper layers of water have ___ salinity - โ๏ธ lower Sea ice is ___ and these are filled with ___ - โ๏ธ porous, higline brine What turns Arctic ice brown? - โ๏ธ Photosynthetic diatoms (ice algae) When the ice melts, blooms create high P.P. which supports marine mamals and birds Polynyas - โ๏ธ Year round areas of open water in ice cap Caused by currents and warm water High P.P in spring (no ice blocking light) Antarctic Waters (Southern Ocean) - โ๏ธ Not landlocked No low saline layer No river sediment (no hard bottom) Continental shelf is narrower and steeper Ice shelf almost disappears in summer Antarctic P.P. - โ๏ธ Very high Thinner ice supports large pop. of diatoms Nutrient rich waters (permanent upwelling) Supports krill What eats krill - โ๏ธ Blue/right/fin/grey whales, Penguins, Crabeater seals, leopard seals, squid Anchor Ice mortality - โ๏ธ Very cold seawater freezes around organisms, buoyant ice lifts organisms Ice Fish - โ๏ธ Many lack hemoglobin (red blood cells)
Use mesenterial filaments to digest neighbors Nutrient limited by algae and seaweed growth Neritic Zone - โ๏ธ Epipelagic waters over continental shelf Oceanic Zone - โ๏ธ Water beyond continental shelf Epipelagic Zone (photozone) - โ๏ธ Surface to 200m Enough light to support photosynthesis Nekton - โ๏ธ Large, active swimmers Eat plank and other nekton Increase resistance for sinking (plankton) - โ๏ธ flat body shape, spikes, chains Swim Bladder - โ๏ธ Gas filled chambers Regulates buoyancy Shark Buoyancy - โ๏ธ Large fatty livers and stiff pectoral fins for lift Lateral Line - โ๏ธ System of canals along body of fish; can detect vibrations/ movement of water Countershading - โ๏ธ dark on top, light on bottom Red Muscle - โ๏ธ High levels of myoglobin, stores lots of oxygen White Muscle - โ๏ธ good for short bursts of power Rete Mirabile - โ๏ธ Special system to retain heat in muscles for better efficiency Ex: tuna, sharks, billfihes Allows them to be endothermic Mesopelagic Zone - โ๏ธ Twlight Zone Not enough light for photosynthesis Bathypelagic - โ๏ธ 2000-4000m Deep ntinental slope/rise
Hadalpelagic - โ๏ธ Trenches; very deep Deep sea environment - โ๏ธ High pressure, cold, consistent salinity, low oxygen=slow metabolism, little variation Abyssal Plains - โ๏ธ Most of deep ocean, low biomass, high diversity Hydrothermal vents - โ๏ธ Localized and temporary high biomass/ low diversity Hermaphroditism - โ๏ธ Posses both sexes; guarantees mating Esca - โ๏ธ Fleshy thing that looks like a lure (biolum.) Ex: Angler fish Chemosynthetic Bacteria - โ๏ธ Thermophilic process escaping hydrogen sulfide to organic material Trophosome - โ๏ธ Organ that contains chemosynthetic bacteria Cold Seep Community - โ๏ธ Methane or sulfide released from sea floor provides material for chemosynthetic bacteria to make organic material Organisms have endosymbiosis relationships with bacteria More long lasting than vents Seamounts - โ๏ธ Localized underwater mountains that don't reach surface Support high prod. And large fisheries Dominated by non-photosynthetic corals, sponges, suspension feeders
