EVE 12 Final Study Guide
EVE 12 Final Study Guide EVE12
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EVE 12 FINAL STUDY GUIDE 1. How can we define biodiversity? a. Species richness: the number of species in a community b. Dominance: one species has a very high abundance (species with low abundance could go extinct and decrease biodiversity) c. Evenness: all species have relatively the same abundance 2. Define chemosynthesis. a. Chemosynthesis is the process by which inorganic matter (chemicals) are converted into organic matter (sugars). Chemosynthesis supports hydrothermal vent food webs in which bacteria use H2S to make organic matter. 3. What are hydrothermal vents? a. Hydrothermal vents are the birthplace for the sea floor and are extreme environments yet extremely rich in biodiversity. 4. List the important physical and chemical facts about the ocean. a. Chemical composition: seawater is 96.5% water and 3.5% dissolved salts that are found in constant compositions meaning that the ratios of these major ions are constant, the salinity of the water makes it very dense (means that the ocean has a lower freezing point than fresh water and is well buffered and able to absorb carbon dioxide) b. Strong fluid forces: marine life is buoyant in dense seawater and can collapse under the force of gravity when on land c. Energy for life comes from the sun but can only penetrate about 200ft into the ocean (this zone is called the photic zone). Blue light penetrates the furthest giving the ocean its color d. The sea is cold: most of the ocean is at about 4 degrees Celsius, thermocline: sharp change in temperature at 4 degrees Celsius at about 1000m depending on the location e. High viscosity: seawater is sticky and resists flowing, creates a drag force: the force of a flowing fluid on an organism i. Adaptations to resist drag include strong attachments to the benthos and to rocks, elasticity and streamlining 5. What is a complex life history? a. More than one stage, larval forms b. Metamorphosis during which morphology dramatically changes c. Settlement into adult habitat 6. Why is fluid flow important for reproduction? a. Transports reproductive particles, food, essential molecules for life and removes waste products b. Also allows for chemical signaling since much of the ocean is dark and organisms can’t see their mates 7. What are the major currents in the ocean? a. Major ocean currents are driven by heating and cooling of the earth b. Thermohaline circulation: the conveyor belt global circulation of ocean water between the surface and deep water layers, is the result of changes in the density of seawater c. El Nino: a normal ocean climate cycle with higher than average temperatures every 7 years followed by a colder than average cycle d. Harmful algal blooms (HABS) are unprecedented warm cycles that cause algae to reproduce and release toxins that are harmful to wildlife and humans 8. What is a hermaphrodite? a. An organism that possesses the reproductive organs of both a male and female 9. What is broadcast spawning? a. Organisms release sperm and eggs into the sea (dependent on fluid flow to fertilize), successful reproduction is left up to chance and there is no parental care involved 10. List the major modes of reproduction in the sea? a. Cloning: some organisms can break off pieces of themselves that will grow into an entirely new individual b. Broadcast spawning c. Internal fertilization (sex) 11. What are the risks of sex in the sea and adaptations to reduce these risks? a. Sex can be costly in terms of energy, organisms can harm each other (komodo dragon’s reproduction can cause injuries) b. Many organisms clone themselves or perform broadcast spawning to reduce the risks to their own well being c. Example: male deep sea angler fish will parasitize the female to ensure reproduction 12. What is the difference between phytoplankton and seaweeds? a. Phytoplankton: microscopic single celled algae that float in the pelagic zone b. Seaweed: multi celled marine alga that live in the coastal intertidal and subtidal zone and are typically attached to the sea floor 13. What is upwelling? a. Cold, nutrient rich water rises from the deep to replace surface waters that are pulled away by winds and the rotation of the earth b. Some of the most productive areas of the ocean c. CA is one of 4 upwelling systems in the world 14. What is primary production and why is it important? a. Primary production is the base of any food web. It involves making organic molecules like sugars from inorganic molecules (sunlight or chemicals). It provides the food for herbivores and carnivores. Photosynthesis is the primary mode of production except in deep and dark waters where chemosynthesis becomes the method for primary production. 15. What are angiosperms? a. Green plants that produce by flowering (producing pollen and seeds). They are vascular plants and have veins to transport water and sugars as well as true roots, leaves and stems. 16. What is meant by trophic support? a. The provision of food for animals in the food web (food web support). For example, seagrass provides herbivore trophic support as they eat living plant tissue and support for detritivores when they die and form detritus. 17. What is the difference between grazerbased and detritusbased marine food webs? a. Grazer based food webs mean that small fish, invertebrates and other herbivores comprise the primary consumer level b. Detritus based food webs mean that the primary herbivorous consumers feed on detritus like dead kelp or seagrass 18. Kelps are brown seaweeds. How are kelps different from other brown seaweeds? a. Brown kelps grow to be extremely large and tall and are found in cool waters on rocky shores. 19. Name and contrast major groups of marine primary producers. (How do they differ in habitat, in morphology, in reproduction?) a. Algae: photosynthetic aquatic organisms that lack true leaves and roots and don’t flower to reproduce b. Phytoplankton: microscopic single celled algae that float in the pelagic zone c. Seaweed: multi celled marine alga that live in the coastal intertidal and subtidal zone and typically attached to the bottom. They need more light to survive and grow. They have a complex life history including a sporophyte phase, which produces gametophytes, which then produce gametes. 20. What areas of the ocean are most productive and why? a. Upwelling zones and coastal areas of the ocean are the most productive because of the nutrient rich waters that well up and because of the high biodiversity associated with kelp based food webs. The CA coastal upwelling zone is one of four upwelling zones on the planet. 21. Marine primary producers are important for life in the sea (question #1), but some marine primary producers have negative effects on humans. Describe an example. a. Algae, when reproducing in large amounts, secrete toxins that can travel through the food web and kill humans. The “red tides” are caused by toxic dinoflagellates with reddish pigments that reproduce so rapidly they color the ocean red. They can cause paralytic shellfish poisoning. 22. List ways that humans benefit from seaweeds. a. Many use it as a source of food, health supplements and for cosmetics. Kelp is valued at 149 million dollars annually in the US. 23. What is detritus? a. Dead organic matter that floats to the bottom of the ocean. This includes dead animals and primarily dead plants or seaweed. 24. What is ‘top down control’? Control of what? Provide a specific example. a. Predators can keep dominant organisms in check and prevent them from outcompeting other species. The loss of top predators can result in a loss of marine biodiversity. Otters prey on sea urchins, which eat kelp. If there aren’t any otters, sea urchins will proliferate and consume all of the kelp resulting in a loss of habitat and food source for many other species. 25. What adaptations do phytoplankton have for life in the pelagic zone? a. Gas bubbles for buoyancy b. Increase their surface area by developing long processes (spines) and form chains and colonies 26. Draw and label a phytoplanktonbased food web and a kelpbased food web. a. Planktonic food web: phytoplankton as primary producers, zooplankton as herbivores/grazers/primary consumers, one or more levels of consumers, apex predators b. Seaweed based: seaweed as primary producers as well as some algae, small fish and sessile invertebrates as primary consumers as well as sea urchins, crabs, sea stars, larger fish and predatory invertebrates as secondary consumers, otters as apex predator 27. How are marine angiosperms (seagrass, salt marsh plants, mangroves) similar and different? a. Seagrass: has rhizomes (underground stems) and leaves that are bundled into leaf shoots, simple life history of pollen, flowers and seeds, provides sediment stabilization, coastal protection, refuge from predators and nursery areas for many species. b. Salt marsh plants: pickleweed, CA cordgrass (invasive east coast cordgrass grows in tight clumps, fills in mudflat habitat important for shorebirds and traps sediment/fills in channels) c. Mangroves: tropical marine trees that form intertidal forests, are flowering trees, have prop roots for stabilization and aerial roots to provide oxygen in low oxygen sediments. They drop leaves to get rid of excess salts. d. All are vulnerable to eutrophication (too many nutrients which leads to the blooming of algal epiphytes and blocks light and CO2 from the seagrass), non native species and habitat destruction 28. Name adaptations of marine angiosperms to the ocean environment. Be specific about which type of angiosperm. a. Mangroves have prop roots to anchor them just as seagrasses have rhizomes to hold them down in the sediment. Mangrove trees can drop leaves or “sweat” out excess salt. 29. The eastern cordgrass (Spartina alterniflora and its hybrid) is an example of a non native species that became invasive. Define invasive species. This example illustrates why new invasions should be ‘nipped in the bud’ as soon as they are found. Explain the rationale behind this management strategy. a. Invasive marine species are nonnative species that can be harmful to native sea life and marine natural resources. If we don’t control invasive species, they can outcompete natural plants and animals and end up destroying ecosystems 30. One consequence of global warming is that sea level is rising rapidly. How would sea level rise affect coastal vegetated ecosystems (seagrass beds, salt marshes, mangroves, but also the seaweeds: kelps, intertidal and subtidal seaweed beds)? a. Light can only penetrate so far into the water so a rising sea level would mean less access to sunlight and CO2. This would greatly decrease primary production. More water also means more fluid flow so seagrasses that aren’t used to extreme drag forces might be unable to survive. Seagrasses and mangroves are only so tolerant to salt so being submerged in salinity levels high than normal could cause them to die. 31. How do cnidarians (sea anemones, sea jellies, corals, hydroids) feed? What does their body look like? (polyp, medusa, soft, tentacles surround mouth, radial symmetry) a. Polyp: mouth up b. Medusa: mouth down c. They use tentacles around their mouth to sweep nutrients from the water column into their mouth (filter feeders) 32. Molluscs are diverse. They are separated into types (classes) based on their shells. a. Gastropod = marine snail = single shell b. Bivalve = 2 shells hinged together (clam) c. Nudibranch (nude branchia or gills) = no or small internal shell d. Cephalopods = no shell/remnant internal shell (except for the ancient chambered Nautilus, which retained an external shell) 33. Marine worms are also diverse and form several different phyla. Describe how segmented marine worms (annelids, polychaetes) obtain food. a. Predators (carnivores) of other worms, mollusks and crustaceans b. Filter feeders: actively filter phytoplankton from the water column c. Suspension feeders: pull particles of organic matter from the water column or the benthos 34. How are invertebrates categorized into major groups (= the phyla on the ‘tree’ or cladogram)? a. Larvae, body covering, symmetry, cellular organization, segmentation 35. Can you describe the major characteristics of sponges (Porifera); sea anemones/corals/sea jellies (Cnidaria); molluscs (Mollusa); segmented marine worms (Annelida) a. Porifera: have pores called ostioles for suspension feeding (specifically filter feeding: feeding on particles suspended in the water column and actively filtering plankton from the water) and spicules that provide structure, they reproduce with larvae b. Cnidaria: soft body, radial symmetry, tentacles for feeding and nematocysts (stinging cells) for killing and defense, carnivorous (some have symbioses with polyp: mouth up or medusa: mouth down), planula larva c. Molluscs: calcified shell (external or internal), muscular foot, radula (tongue like organ) with exceptions, veliger larva i. four groups include gastropods, bivalves, nudibranchs, cephalopods d. Annelida: segmented words characterized by bilateral symmetry, segmented body, trochophore larvae with ciliated ring 36. Describe different feeding modes, an example of an invertebrate for each mode, and where it would appear in a food web. a. Suspension feeding: found at the primary consumer level b. Filter feeding: found at the primary consumer level (Porifera) c. carnivorous feeding: found at the primary or secondary consumer level (Cnidaria) 37. What are the major distinguishing characteristics of the crustaceans versus tunicates and sea squirts and phyla covered in Invertebrates I? a. Crustaceans (barnacles, shrimps, crabs, lobsters): hard tunic covering a soft body, segmented limbs, antennae, bilateral symmetry b. Sea squirts/tunicates: no backbone but have a nerve cord, siphons to squirt and suck water, sessile, evolved chemical defenses against predators c. Cchnodermata (sea stars, sea urchins, sea cucumbers): radial symmetry, endoskeleton, water vascular system and tube feet, pluteus larva 38. Define invasive species and discuss one marine invasive species (Phylum, mode, habitat, ecological effects) a. Invasive species are non-native species that outcompete native species or cause economic/ecological harm to a native ecosystem b. The invasive Chinese mitten crabs clogged the Tracy Fish Collection Facility and caused countless deaths of endangered salmon and cost CA one million dollars to redesign the aqua-duct facility 39. What is the different between a mutualism and a commensalism? a. Mutualism: both organisms benefit, it’s a win-win situation b. Commensalism: one organism benefits while the other is unaffected 40. List general ways in which positive interactions benefit the partners? a. Mutualism can lead to habitat, protection, food, and the removal of parasites 41. List the partner species mutualism and a commensalism and the specific ways both or at least one benefits a. Bobtail squid bacterium symbiosis: the squid are hidden from their predators and the bacteria receive carbon and nitrogen b. Clownfish anemone mutualism: the anemonefish chase away predators and increase fluid flow for the anemone, while the fish are protected from the anemone’s toxic stinging cells and get to scavenge left over food 42. Under what environmental conditions do you expect to find positive interactions? a. we would expect to find these interactions under normal environmental conditions (not global warming conditions) b. ocean acidification due to global warming is already interfering with the clown-fishes’ ability to find anemone habitats c. warmer ocean temperatures are also causing coral bleaching (corals release their symbiotic algae when stressed) 2ND HALF OF QUARTER 1. What are the distinguishing features of vertebrates (Phylum Chordata) and how do they differ from invertebrate phyla? a. Vertebrates are characterized by a backbone and a series of vertebrate bones that enclose a nerve cord. Invertebrates lack these bones as well as the central nerve cord. 2. What are the major distinguishing features of families of fishes? a. Sharks and rays (or rayfinned) fishes: These organisms lack calcified bones and instead, have a skeleton of cartilage. Sharks have dorsal and tail fins while rays have a flattened body with both eyes on their dorsal side. b. Families of bony fishes: Bony fishes have a skeleton comprised of calcified bones (see each family’s characteristics below). 3. What is a lateral line and what purpose does it serve? a. A lateral line is essentially a sensory system. Through a series of pores between their scales, fish can sense pressure waves created by water flowing around them. The pores connect to nerve cells (neuromasts), which are connected to the brain. The lateral line is why schools of fishes never run into each other and why they stay streamlined and balanced despite drag. 4. Describe the feeding modes of fishes and name a specific species for each mode. a. Fish can be filter feeders, meaning that they filter particles from the water column. They can be herbivores that feed on sea grass, seaweed or coral. They can also be predatory and can eat other, smaller fish. 5. What species or kinds of fishes are experiencing population decline and what is a cause of each decline? a. Sharks are currently experiencing a serious decline, as they are deliberately overfished for food, fins and chonodroitin. They are also caught in fishing nets and are victims of bycatch. Sharks, in particular, are vulnerable to extinction because they recover slowly from population decline. They reproduce late in life (621 years) and only have a small number of pups (810 every other year), which means that if juveniles are killed or caught, they won’t be able to add to the population count. 6. What is broadcast spawning? Name a fish example (What other groups/phyla of sea life are broadcast spawners? a. Broadcast spawning refers to casting eggs and sperm into the water and relying on fluid flow to fertilize the eggs. Larvae develop in the water but are prey for other predators that are feeding on the zooplankton. Pacific Herring broadcast spawn in order to reproduce. 7. What is a serial hermaphrodite? Name an example a. A serial hermaphrodite is an organism that changes gender during its lifetime. The Barramundi cod begins life as a female and eventually changes into a male. The CA Sheephead is also an example of a serial hermaphrodite. 8. Name a fish family that does not free spawn and describe how they reproduce? a. Pipefish and seahorses both bear their young live. The male seahorse will actually practice parental care after the young are born. These organisms have a simple life history. Bony fishes (distinguishing characteristics, trophic levels, reproduction, morphology) a. Herring: i. Free spawners (freely release sperm and eggs, no physical mating) ii. Fertilized eggs develop into larval fishes in the zooplankton community, iii. The last urban fishery is in CA and they are in serious decline b. Seahorse/pipefish i. Long snouts, slender bodies with bony segments, very slow moving, camouflage well ii. Seahorses have prehensile tails, use suction feeding: open mouth quickly and engulf their prey whole, eat small crustaceans) iii. Simple life histories c. Parrotfish:(wrasse family) i. Powerful herbivores ii. Distinguished by big scales and swim with pectoral fins, teeth fused into a beak, hard mill in esophagus to grind plant matter iii. Some species switch from seaweeds to corals as adults, Mill grinds up food, including the calcium carbonate skeletons of corals. Produce coral sand iv. Sleep in mucous nests (Open at the ends for water flow, secreted in 30 minutes, protection from predators, sleep behavior makes them vulnerable to capture by divers) a. Butterflyfish: eastern triangular butterflyfish, Indo Pacific, i. Deep bodies, eye stripe, small mouths, ii. Eat coral polyps, also small crustaceans and worms iii. Typically swim in pairs b. Triggerfish: Front dorsal spine that erects and locks into place if a predator tries to pull them out of a crevice i. Heavy body and strong sharp teeth, they blow jets of water out of their mouth (they will blow sand away from nest, which they guard, this aerates the nest) ii. The Titan triggerfish is the largest species (3ft long) and is aggressive to divers, other triggerfish species feed on zooplankton during the day, (red toothed triggerfish) c. Anglerfish: include frogfish and the deep sea anglerfish i. Modified first dorsal spine (esca) ii. Functions as a lure for prey iii. Large upturned mouths open wide to engulf prey iv. Camouflage very well, Good for ambushing prey or avoiding predators d. Tuna: apex predators and sport fish i. Sleek form, silver blue color, finlets (short dorsal fins) ii. Built for cruising 1. Pectoral fins fold into groove 2. Eyes do not protrude 3. Swim continuously for oxygen delivery to gills and to maintain buoyancy 4. Aerobic, high metabolic rates 5. Require high blood flow and O2 6. Heart pumps fast at low temperatures 7. Circulatory system conserves heat iii. Northern bluefin tuna 1. Heavily hunted for food sushi, $50,000 per tuna 2. Open ocean farming for bluefin tuna is being tested in New Zealand and Mexico 3. All species of tuna are prized as game fish d. Causes of population declines in fisheries i. Over fishing for food, medicine ii. Accidental by catch in nets/trawls/dredges iii. Loss of spawning habitat iv. Pollution 9. Marine fish conservation what are some different strategies to conserve marine fish populations a. Fisheries regulations to limit how many fish can be harvested, breeding and harvesting fish in man made hatcheries so as not to deplete wild populations b. Marine protected areas: areas where disturbances to marine life, even fishing, are restricted 10. What are the shared distinguishing features of sea snakes, birds, and reptiles? a. Lay eggs b. Scales or modified scales c. Lungs-air breathers 11. What is the difference between snakes and birds? a. Birds have scales modified into feathers b. Endothermic (warm blooded from regulating their temperature) 12. Discuss the factors that threaten a marine reptile (including birds) with extinction. a. Marine plastic: effects of plastic ingestion include ulcerations, infections, reduced meal size and lower breeding success b. Loss of habitat due to development/agriculture c. Pollution, some birds like the pelicans are still recovering from DDT 13. Discuss the special adaptations of a species or ‘group’ of marine reptiles (which include birds). a. Sea snakes are adapted to living in the sea i. They have long lungs and can dive up to 150m and study underwater for 2 hours ii. They have a salt excretion gland under their tongue iii. They shed their skin every 26 weeks to reduce their fouling community iv. They have narrow heads to poke into cracks and crevices in reefs (eat benthic fish) 14. Discuss the role of a particular marine species in a food web. What does it eat, what is its foraging behavior, what type of food web does it belong to? a. The green sea turtle is the only herbivorous species of sea turtle. They prefer to eat sea grass by clipping it and returning about a week later to clip it again. They are threatened with extinction because of their tendency to develop tumors. 15. Why are populations of murres and auklets (species of sea birds) declining in CA Upwelling Ecosystem? a. Domoic acid build up (caused by dinoflagelletes releasing toxins in response to warmer waters) is causing an accumulation of those toxins in fish, which are eaten by the murres and auklets. 16. Major Characteristics of coral reefs a. Coral reefs occur where conditions are right for coral growth (warm, clear waters, limited sedimentation) and they thrive where herbivores are abundant b. They form massive structures of calcium carbonate that are home to exceptionally diverse sea life. c . Reef morphology i. Fringing: grows next to land ii. Barrier: grows as a barrier further offshore and has a sandy lagoon between it and the land, often covered with sea grass beds iii. Atoll: all that remains of a sinking volcanic island d. Phylum Cnidaria (tentacles, nematocysts, radial symmetry) and are colonies of polyps, many have symbiotic algae (zooxanthellae), ~halfanimal, halfplant and they can reproduce asexually and sexually. e . Reef zonation by depth i. Shallow: fastgrowing species: leaf like and highly branching ii. deeper zone: dominated by sponges that help glue the coral framework together iii. soft corals/sponges: don’t secrete a skeleton, sea fans and sea whips f. Competition is fierce i. Result is often a dead zone between two different species, they can overgrow and even eat their competitors g. Many ecological interactions occur on reefs i. Predation: killed by crown of thorns sea star, susceptible to plagues, soft corals eaten by fireworms or gastropods ii. Symbiosis: coral zooxanthellae, banded coral cleaner shrimp h. Coral reef ecosystems are threatened in numerous ways i. Hurricanes and tsunamis ii. Dynamiting for fishing iii. Coral sands used as beach replenishment as well as sedimentation from coastal development iv. Overfishing of top level predators allows coral predators to flourish v. Eutrophication causes seaweed growth (high competition for corals) vi. Disease vii. Climate change: ocean acidification viii. Aquarium trade and aquaculture 17. Summarize human uses of sea life from this and previous lecture for each use, which habitat is most affected? Which specific organisms are most affected by each use? a. Sustenance: tribes like the Inuit and the Makaw abide by rules set by committees such has the International Whaling Commission, which sets quotas on the number of animals that can be taken for sustenance b. Hunting: must be done sustainably, limits on what can be fished recreationally c. Fishing: must stop exploiting populations that take a long time to recover or that are threatened, we must also figure out alternative methods for fishing because by catch/trawling/cyanide/bombs are harming ecosystems and non target species d. Drugs from the sea: marine invertebrates synthesize chemicals for defense that are being used in cancer research trials and that have been found to have anti bacterial/fungal/inflammatory properties, must ensure that species aren’t exploited for the procurement of these chemicals e. Marine ornamental species: shell collecting can be sustainable, aquarium trade can provide livelihoods in developing nations (the family raising seahorses made more money than fishing), the MAC regulates the aquarium trade by creating standards and limitations on how many species can be taken f. Mineral extraction: bad for the environment (salt ponds in SF are now the largest salt marsh restoration project in the US), gas and oil are easily obtained and are cheap sources of energy but oil spills like Deepwater horizon have been disastrous g. Waste disposal: ocean dumping is convenient and inexpensive but overburdens the ocean, causes desalination and introduces chemicals into the water, landfill can be reused but require maintenance, planning and operation h. Marine tourism: can provide income and jobs and is environmentally sustainable when practiced correctly 18. Contrast the benefits and costs of aquaculture, of oil and gas extraction, of marine tourism. a. Aquaculture: must be economically easy to grow and feed and must not interfere with natural populations in order to be sustainable, also can’t introduce pollutants or invasive species into the natural habitat b. Oil and gas extraction: currently unsustainable due to the rate at which we are exploiting these resources, oil spills and contaminations have been incredibly detrimental to marine habitats, popular because it’s cheap c. Marine tourism: provides income for developing nations and benefits everyone when it is done in a sustainable manner, maintenance of tourism can also provide jobs 19. What is the difference between an MPA and NMS? What shared goal do they have? a. An MPA is protected from human activity and includes bans on fishing. An NMS is only protected from oil, gas and mineral exploitation. They both are intended to protect marine habitats as well as declining species. 20. Discuss why the California Coastal Upwelling Ecosystem is important enough to be designated both as a MPA and NMS. a. The CA coastal upwelling ecosystem is one of only four upwelling systems on the planet. It is home to some of the richest waters on earth and has the largest concentration of breeding sea birds in the US. It is home to over 240 species of fish and harbors one third of the world’s whale and dolphin species. It also has the largest concentration of blue whales on Earth. 21. What is fisheries bycatch and why is it a problem? a. A species caught accidentally in a fishery that is designed to a target a completely different species group. This can also include the capture of reproductively immature juveniles of the target species. 22. Define ‘fishing down the food chain’? a. Humans will fish out a favored species and then switch to a less tasty, smaller species. More and more species are thus becoming overfished. 23. What are risks that airbreathing mammals face when diving and what adaptations so they have for diving? a . Breath holding dangers i. Suffocation ii. Lack of oxygen causes a carbon dioxide build up and leads to anaerobic metabolism (lactic acid built up) b Diving dangers i. Decompression sickness (the bends) ii. Pressure trauma (crushed tissues) c . Diving response i. High capacity for storing oxygen in blood (not large lungs!) ii. High blood volume (22% vs. human 7% of body weight) iii. Redirection of blood flow to the brain, heart and essential organs iv. Decline in heart rate (bradychardia) v. Brain and heart tolerate low oxygen d. Decompression sickness: the bends due to air bubbling in blood and tissues upon rapid ascent i. Alveoli (air pockets at the very end of the airway in the lungs) collapse ii. Gas exchange with blood is minimal e . Pressure trauma i. Flexible ribs and lungs allow them to collapse ii. Diaphragm allows stomach and intestines 24. What are causes of population decline of marine mammals? Provide at least one example for a specific species (name the species). a. The sea otter population experienced a drastic decline due to mortalities caused by the parasite Toxoplasma gondii. The parasite was transmitted into the ocean from cat feces deposited on land. Sea otters are declared as endangered in the US. b. Marine mammals are declining due to pollution, habitat loss and over fishing (see below). 25. Describe the social, feeding, and reproductive behaviors of different species of marine mammals. a. Sea lion (pinnipedia): ear flap and long flippers, very playful and social, breed on offshore islands, eat rockfish, squid and salmon b. Harbor seal (pinnipedia): no ear flaps, short flippers, prefer fish, mating in the water c. Northern elephant seal (pinnipedia): 80% of time at sea, migrations as far as Alaska, eat squid and fish, migrate for mating and for molting d. Leopard seal (pinnipedia): solitary and aggressive, eats krill but will kill and eat other marine mammals e. Manatee (sirenia): 6 vertebrae, cannot turn head, single lobed tail, split lip, hairs on mouth, eyes shut like a camera shutter, herbivores, mouths adapted to eat plants, females bear claves at 710 years, lots of parental care f. Dugons (sirenia): 6 vertebrae, cannot turn head, 2 lobed tail, unsplit lip, no mouth hairs, same reproductive cycle as manatee, eat sea grass g. Polar bears (carnivora): declining since 1985, listed in 2008 as threatened with extinction h. Sea otters (carnivora): control urchins in top down control in giant kelp forests, populations currently increasing due to being protected i. Baleen whales (cetacea): sieve zooplankton through keratin tubules, can be passive feeders (filter feeding, swimming in a V formation) or active feeders (actively pursue and coral their prey) i. Active feeders are more streamlined and hunt cooperatively side by side or in a tight cluster, includes minke, blue and humpback whales ii. Passive feeders include right, bowhead and gray whales iii. Blue whale: largest on earth, call is the loudest and deepest made by animals iv. Humpbacks: long flippers, bumps on their heads, corral their prey in a bubble net j. Toothed whales (cetacea): prey on fish and squid, use clicks for echolocation, swim in organized schools and hunt together i . Dolphins: extremely social, swim in schools and feed on pelagic fish, very smart and are being used in the Navy to find under water mines ii . Sperm whale iii . Beaked whale iv. Killer whale: 2 most widely distributed mammal on earth, preys on other marine mammals, travel in matrilines (3 generations), pods (related matrilines) or cians (pods with similar vocal dialects), community groups stay in the same area while transient groups travel, endangered due to pollution and decline in salmon v. Beluga: white whale, eats benthic prey, herring and small fish, only whale able to turn its head, travels in triad (mother, calf, newborn), nursery groups (several triads) or aggregations (1000 whales in the summer), complex social interactions vi. Narwhal whale: restricted to the arctic, develop a long horn due to fused teeth 26. What species are natural predators of marine mammals? a. There are few natural predators of marine mammals. The few include humans, killer whales, crocodiles and sharks. Marine mammals are more threatened by bycatch, ship strikes and pollution because most of them reproduce slowly and it thus takes their populations a long time to recover from a decline. 27. What is the difference between baleen and toothed whales? a. Baleen whales are filter feeders that sieve their prey through a baleen. Toothed whales are more active hunters and consume their prey using their teeth. Toothed whales also use echolocation to find their prey. They are more social and hunt in groups. 28. Describe migrations of marine mammals (and recall migrations of sea life from earlier lectures). a. Cetaceans (whales and dolphins) complete long migrations between feeding and mating/calving cycles. 29. What are the distinguishing differences between marine mammals and other vertebrate groups of sea life a. Mammals are endotherms (warm blooded) meaning that they can regulate their body temperature. They have hair and bear their young live (simple life history). They also nurse their young and practice parental care. They tend to complete long migrations. 30. Increasing concentrations of atmospheric carbon dioxide is the cause of global climate change. What are its two major effects on the ocean environment? a. Global warming on land and in the sea has caused the sea level to rise and has increased the frequency/intensity of storms. This causes problems for undersea creatures, who are combating more turbulent waters and different pressures due to the sea level rise. The warming has also caused ocean acidification, which has destroyed crustaceans’ ability to form their calcium carbonate shells. 31. In addition to global climate change, humans have had other effects on sea life. List and discuss the effects a. Habitat modification has arisen in addition to coastal development and aquaculture. This has resulted in the loss of sea grass, salt marshes and mangroves (marine wetlands). b. Eutrophication: Human production of nitrogen in the industry and use as a fertilizer has increased dramatically. In the sea it leads to phytoplankton blooms (HABS). The phytoplankton die and decompose using up oxygen, creating dead zones. These zones have been labeled as hypoxic and are occurring off the Pacific coast in the summer. 32. Define invasive species. Why are they are problem in the sea? a. Invasive species are nonnative to an area and can outcompete or prey on native species, ultimately resulting in a loss of biodiversity. They can disturb the balance of natural ecosystems and are one of the major causes for endangered/threatened species (6%). With the increase in storms and thus water flow, it is increasingly less difficult for species to be swept to an area they don’t belong in. For a native organism, competing with an invasive species and dealing with global warming at the same time can be too much. 33. What are the major causes of extinction of marine species? Name some endangered species. a. Overexploitation: fishing, over harvesting b. Habitat loss and degradation due to coastal development and sailing c. Invasive species that outcompete native ones d Pollution, climate change and disease e. Examples of endangered species: salmon, cod, sea otter, pacific herring, orcas (due to pollution), all species of sea turtles 34. What are 5 things each of us can do to reduce the impact of humans on sea life? [Hint: read the box in your text] a. Increasing energy efficiency: more efficient power plants, electrical grids, homes and cars will reduce reliance on non renewable fossil fuels b. Reducing wasteful consumption: better estimating and growing the amount of food we need, composting and recycling c. Reducing subsidies on fossil fuel use: diverting money investments from fossil fuels to green energy d. Reversing wetland, streamside vegetation and forest loss: management plans to restore these areas e. Controlling the main sources of anthropogenic nitrogen: remove and control reactive nitrogen
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