Marine Ecosystems Exam 1 Study Guide

Divergent Plate Boundaries

-A divergent plate boundary within continental crust causes continental rifting -If successful, this leads to the formation of a new ocean. A divergent plate boundary within oceanic crust causes seafloor spreading Driving force for divergent motion: -Heat rising from the core-mantle boundary moves upwards through the lower mantle and asthenosphere as mantle plumes

Commercial Uses for Seaweeds

-Algin: obtained from kelps, is used as a emulsifier in many food items and in the making of many products -Carrageenan: harvested from red seaweeds, is used as a thickening agent in dairy products such as yogurt and milkshakes -Agar from red seaweeds is used to culture microorganisms in the healthcare industry, as a thickener in foods, filler in pharmaceuticals and cosmetics, and to protect canned meats

Walrus (Order Pinnipedia)

-Odobenus rosmanus -Absence of external ears -Both males and females possess large tusks, but adult males are slightly larger than females, with longer and stouter tusks -On land, walruses are capable of rotating their hind flippers to walk on all fours as in sea lions -Food: mainly bivalve mollusks (clams); also other benthic invertebrates like worms, snails, sea cucumbers, squids, and crabs. May occasionally prey on fishes such as polar cod and scavenge on seal carcasses -Arctic Sea - both Pacific and Atlantic -In relatively shallow water. Migrates with pack ice, some aggregating in small rocky islands and coasts in summer -Delayed implantation; females give birth every 2 years -Copulation and nursing in the water

Colubrine or yellow-lipped sea krait (Laticauda colubrina)

1. Amphibious or semiaquatic sea snake that lives in shallow tropical reef environments in eastern Indian and western Pacific oceans (coasts of Bangladesh, Thailand, Myanmar, Thailand, etc.). However, they are also suited for land. They have intermediate traits between sea snakes and terrestrial elapids (family of venomous snakes) 2. Frequently goes to shore, including going to lay their eggs on land -They are the only oviparous sea snake genus 3. They have powerful venom that will paralyze the victim, in fact, it is one of the most toxic snakes in the world 4. Compressed and rudder-like tail

Solute/Water Balance

1. Osmoconformers: -Their internal concentration varies as the salinity in the water around them changes -Do not attempt to control solute/water balance -Most can only tolerate a very narrow range of salinities 2. Osmoregulators: -Organisms that control their internal concentrations of solutes and water -This can be done in a variety of ways, like secreting very little urine or specialized glands to secrete salts -Can generally tolerate a wider range of salinities than osmoconformers

Groups of Marine Mammals

1. Pinnipeds (Order Pinnipedia) - seals, sea lions, and walrus 2. Carnivores (Order Carnivora) - sea otter, marine otter, and polar bear 3. Sirenians (Order Sirenia) - dugong and manatees 4. Cetaceans (Order Cetacea) - whales, dolphins, and porpoises

Archaea and Bacteria

Archaea and Bacteria Characteristics: 1. Prokaryotic - no nucleus -Single chromosome (normally circular) -Most with cell wall -Great metabolic diversity 2. Archaea -Ancient organisms - fossils found that date back 3.8 billion years -Variety of metabolic types -Widely distributed at sea -They can tolerate wide ranges in temperature, salinity, and even desiccation (drying out) -They can be found near hydrothermal vents and salts flats, two extreme environments Marine Bacteria -A variety of shapes including spirals, spheres, and rings -Cell wall structure is semi-rigid, but permeable; most with cell wall -Size is normally microscopic, but a few are large -Wide variety of metabolic types -Very abundant worldwide -Break down dead organic matter forming detritus, minute particles of organic matter that are available as nutrition for other organisms -Cyanobacteria - photosynthetic bacteria most important in the marine environment -Stromatolites - massive calcareous mounds formed by cyanobacteria Metabolic Diversity of Archaea and Bacteria -Photosynthesis - derive energy from light -Chemosynthetic - derive energy from chemical compounds -Heterotrophs - derive energy from organic matter by means of respiration

Marine Mammals

Basic Characteristics: -Homeotherms and endotherms: hair (reduced in some species) and a layer of blubber for insulation -All endotherms are homeotherms; however, NOT ALL homeotherms are endothermic. Homeothermy requires metabolic processes to produce heat -Homeotherms maintain a CONSTANT internal body temperature, usually within a narrow range of temperatures -Temperatures are managed within a narrow range -Viviparous with a placenta to provide nutrients to the embryo; this is known as matrotrophy -Viviparity -The presence of mammary glands -Large brain in relative to body size -Complex behaviors

Lophophorates

Characteristics of Lophophorates - feeding structure is known as lophophore (ciliated tentacles); feeding; lack segmentation Examples of Lophophorates: Bryozoans: form colonies by encrusting seaweed, rocks, and other surfaces; they have interconnected individual organisms known as zooids. Suspension feeders. Bryozoans (together with phoronids and brachiopods) possess a unique feeding structure called a lophophore, ciliated tentacles surrounding the mouth -Phoronids - worm-like; live in shallow marine environments -Lamp shells (brachiopods) - two shells or valves that enclose the body; many fossil species; though they resemble mollusks, they're not. Research has shown distinct ancient lineage

Water as a Solvent, Seawater Composition, Salinity of Seawater, Transparency, Adding Water and Solutes

Water as a Solvent -Water acts as a solvent, which means that substances can dissolve in water. Water is known as the universal solvent -Any substance dissolved in water is known as a solute -Ocean water has solutes dissolved in water. This level of solutes is called salinity Seawater Composition -The main solutes dissolved in ocean water are sodium and chloride -Salinity is measured in parts per thousand (ppt or o/oo). This means that for every 1000 grams of water, there are 35 grams of salt Salinity of Seawater -The salinity of seawater is normally around 35 ppt, but it can vary by location -Ocean water near a location where a river meets the sea can be 15-25 ppt -Other areas can be higher if evaporation is high and no rivers are bringing freshwater Transparency -Water is also relatively transparent -This means that sunlight shining on the surface can penetrate the surface (crucial for photosynthetic organisms living underwater) -This level of penetration varies greatly depending on the amount of solutes in the water Adding Water and Solutes -Water comes from rivers and from precipitation such as rain and snow -And to a lesser extent from melting polar ice -Solutes come from the weathering of rocks, hydrothermal vents, and solutes that were delivered in rivers from land runoff

Sea Turtles

-All species are threatened or endangered -Endangered - a species that is in danger of becoming extinct -Threatened - a species that may become endangered because of low numbers -Threats - used as food by humans; eggs eaten by humans and other animals; individuals getting caught in drift, gill, and shrimp nets; swallowing plastic bags; development of beaches used as nesting areas Seven (or eight) species of living sea turtles: -Green sea turtle (some biologists recognize two species, the Pacific and the Atlantic green turtles), leatherback sea turtles, loggerhead sea turtle, hawksbill sea turtle, olive ridley sea turtle, kemps ridley sea turtle, Australian flatback sea turtle -The body of sea turtles is enclosed by a shell, or carapace -The ribs are fused to the shell -All have powerful jaws with no teeth -Like other reptiles, sea turtles are poikilotherms and ectotherms (exception: leatherback sea turtle is an endotherm)

Invertebrates

-Animals without a backbone are known as invertebrates. Those with a backbone are vertebrates -About 97% of all animals are invertebrates -All major animal groups (or phyla) have representatives in the marine environment -Several animals groups are exclusively marine Characteristics of Animals -Eukaryotic, multicellular, with at least a tissue-level organization (most have organ- and system-level organization) -Heterotrophic (non-photosynthetic) -Require oxygen for aerobic respiration -Most are mobile at least during part of their life cycle -Basic Body Structure (Symmetry): 1. Radial - equal parts radiate out from a central point 2. Bilateral - organism can be divided into right and left halves that are more or less equal 3. Asymmetrical - having no symmetry (sponges)

Transform (strike-slip) Boundary

-Another accommodation for a spherical Earth -Often associated with divergent plate boundaries -Ninetyeast Ridge is a leaky transform that allowed India to move north to collide with Asia. It leaked magma and formed an "aseismic" ridge (non-spreading ridge) -Example: San Andreas Fault, California

Atolls, Seamounts, and Guyots

-Atoll - ring-shaped coral reef system with a central lagoon rising from deep water. -Seamount - mountain rising from the ocean seafloor that does not reach the surface (an "underwater mountain") -Guyot - a flat-topped seamount (often called "tablemounts") Hypothesis for formation of coral atolls -Volcano (in tropics) acquires a fringing coral reef -Volcano becomes inactive and begins to erode and subside (sink) -Coral reef continues to grow upwards at a rate faster than rate of volcano sinking -Eventually, only growing fringing reef remains with deep central lagoon

Levels of Organization

-Atom - fundamental unit of matter -Molecule - two or more atoms chemically joined together -Cell - basic unit of life; consists of different types of molecules -Organelle - specialized constituents within cells -Tissue - group of cells functioning as a unit -Organ - many tissues arranged into a structure with a specific function -Organ system - group of organs working together -Complete organism - typically consisting of different organ systems -Population - a group of organisms of the same species living in the same habitat -Community - all of the species that live in a particular habitat -Ecosystem - a combination of the community and the physical environment

Echinoderms

-Characteristics of echinoderms - based on five parts; pentamerous radial symmetry in adults but bilaterally symmetry larvae; tube feet for moving and feeding; have gills; a brain is absent; ossicles are elements made of calcite that form an endoskeleton Types of Echinoderms: -Sea stars - central discs; they have eyes; perforated plate for entry of seawater; mostly carnivores -Brittle stars - central discs; tube feet without suckers used for feeding on detritus and small animals; no anus, lacks eyes, but they have light-sensing cells all over their body. -Sea urchins and sand dollars - movable spines; mouth and anus are in reverse order; feeding; jaws and muscles for grazing known as Aristotle's lantern; feeds on seaweeds, detritus, and encrusting organisms they scrape off surfaces -Sea cucumbers - mouth and anus on opposite ends; has spicules and not spines; deposit feeders, most species obtaining organic matter from ingested sediment; expulsion of internal organs when threatened, which regenerate. -Crinoids - Five or more arms that branch out for suspension feeding. Mostly in deep water but many inhabit coral reefs; inhabitants in the tropics. Sea lilies live attached in deep water, feather stars crawl on the bottom and live mostly in shallow-water coral reefs. Some use a mucous net to aid in food capture

Tides

-Circulation is also driven by tides, the rhythmic rising and falling of sea-surface levels -The tides are caused by the gravitational pull of the moon on the ocean waters (and to a lesser degree by the Sun) -Waters on the side of the Earth closer to the moon are pulled towards the moon, causing a high tide -Waters on the far side of the Earth are pushed away from the moon, causing a low tide -Most locations have two high tides and two low tides each day, known as semidiurnal tides -Normally tides at night are higher and lower than daytime tides -Number and size of tides varies geographically and can be affected by bottom features and geographic features such as islands, canyons, and reefs -The amount of difference between the high and low tide (tidal range) is also affected by the bottom features -When the Sun and Moon, both of which affect tides, are in line at times of the new and full moon, the tidal range is even greater -These are called spring tides; despite the name, they happen each month -Neap tides occur between the spring tides when the Sun and Moon aren't in alignment Organisms are Affected by Tides -Organisms that live in areas exposed during a low tide are especially affected during spring tides -Movement of water during tidal changes results in significant mixing of water, which also affects organisms -Many organisms time their reproduction according to the tides

Diffusion and Osmosis

-Diffusion - Movement of solutes (substances dissolved in water) from areas where they are more concentrated to an area where they are less concentrated -Osmosis - Movement of water from an area where it is more concentrated to an area where it is less concentrated -Since marine organisms live in a very solute-rich environment, they have a tendency to gain solutes and lose water -This can result in the death of cells if the water loss/solute gain is significant -These organisms must find ways to deal with such diffusion and osmosis

Convergent Plate Boundaries: Ocean Crust - Continental Crust

-Ocean crust is more dense, so it ALWAYS goes down into the mantle. Continental crust does not get subducted -Examples: Cascades Mountains, Andes Mountains -Exotic terranes acret onto a continental margin -Throughout the Mesozoic Era, a series of island arcs collided with western North America. -At least five collided in what is now the U.S. -Even more collided to form western Canada & Alaska.

Temperature Control

-Ectotherms - Generate body heat metabolically but heat is rapidly lost so organisms can't maintain a constant internal body temperature; it matches that of the surrounding environment -Endotherms - Retain most metabolic heat, and body temperature stays higher than that of the surrounding environment -Poikilotherms - Body temperature varies with the temperature of the surrounding environment -Homeotherms - Regulates body temperature so it does not vary as much as the temperature of the surrounding environment -Ectotherms and Poikilotherms: Invertebrates, most fishes, and marine reptiles -Ectotherms and Homeotherms: None -Endotherms and Poikilotherms: Some large sharks, tunas, and billfishes -Endotherms and Homeotherms: Mammals and birds Caveats: -All endotherms are homeothermic -Poikilothermic organisms can be endothermic -Not all homeotherms are endothermic because homeothermy requires metabolic processes to product heat

HMS Challenger Expedition (1872-1876)

-Edward Forbes sailed in the 1840s and 1850s. He carried out trawling of the seafloor, mostly around Britain. -Found that animal density decreased with depth as well as diversity -Vice-Admiral Sir George Strong Nares commanded the expedition -In 1875, the Mariana Trench was discovered. A depth of 5 miles. This is known as the Challenger Deep and is 9 miles. -Discovery of the Mid-Atlantic Ridge -The expedition discovered undersea mountains, life on the ocean floor, salinity, and temperature variations, seawater chemistry, and measurement of ocean currents -As many as 4,700 marine species were discovered. The concept of "extremophiles" was introduced after this expedition

Marine Fungi

-Eukaryotic and mostly multicellular; heterotrophic; most of the at least 1,500 species of marine fungi are microscopic -Like bacteria, many fungi break down dead organic matter into detritus -Some fungi live in symbiosis with cyanobacteria to form lichens -Marine lichens often live in wave-splashed areas of rocky shores and other hard substrates

Marine Mammal Reproduction

-Fertilization is internal (copulation); penis remains within body before copulation in whales -Copulation occurs on land in pinnipeds (except in the walrus) where males compete for "harems." -Other marine mammals copulate at sea -Sexual play is common -Delayed implantation of the fetus allows newborn to be born at a time that is best for its survival (pinnipeds, polar bear, walrus) Gestation and Birth: -Gestation time varies in marine mammals; normally 11-12 months in cetaceans -Calves are born tail first so that they can remain attached to the placenta until the entire body is out and the animal can be forced to the water's surface to take its first breath of air

Key Characteristics of Worms

-Flatworms - Central nervous system with a brain; incomplete digestive tract (gut without anus); bilateral symmetry -Ribbon Worms - Complete digestive tract with mouth and anus; circulatory system; long, elastic body with a proboscis, a long tube used to entangle prey -Nematodes or roundworms - Complete digestive tract; has a nervous system; bilateral symmetry -Arrow worms - planktonic; streamlined body similar to fish; voracious predator that feeds on crustaceans, fish larvae, and plankton. -Segmented worms - internal and external segmentation; a nervous system with a brain; close circulatory system (ex: polychaetes, leeches, beard worms, echiurans); bilateral symmetry -Peanut Worms or Sipunculans - unsegmented bodies; lives in shallow marine settings; deposit feeders, mostly burrowing in soft sediments

Marine Flowering Plants

-Flowering plants, or angiosperms, are true plants, all having true leaves, stems, roots, and conducting tissues -Over 250,000 species exist worldwide, but only a few are truly marine -Must be adapted to live in seawater Seagrasses: -About 60 species in mostly tropical waters; some are temperature in distribution -Flowers are small and inconspicuous in most species -Pollen (containing sperm) is carried by water currents -Tiny seeds, the result of fertilization, are also carried by water currents or in the feces of animals that consume the seagrasses -Seagrasses form highly productive seagrass meadows, or beds, that provide a habitat to many organisms that hide among the leaves -Eelgrass (Zostera) is the most widely distributed of the seagrass, common in shallow, temperature waters around the world

Other Examples of Arthropods

-Horseshoe crabs - living fossils because they have remained virtually unchanged during its 480-million-year history; used to test vaccines for bacteria; dwells in nearshore environments; feeding; uses food to crush food because they lack teeth. -Sea spiders - these are not actual spiders; they mostly live in cold water.

Hotspots

-Hotspots are caused by isolated plumes in the mantle that melt the base of the lithosphere -Melted lithosphere (basalt magma) rises through the oceanic crust and forms a volcano on the seafloor -Hotspots tend to be stationary, so as the plate moves over the hotspot it produces a chain of basaltic volcanic islands -Some hotspots occur on the mid-ocean spreading ridges (e.g., Iceland, Azores, Galapagos) -Many occur as isolated intraplate hotspots (e.g., Hawaii) -Form volcanic islands of basaltic lava, e.g., Hawaiian Islands, Galapagos Islands, Canary Islands -As the island drifts away from the hotspot, the magma source is cut off. The island starts to erode -The ocean crust sinks as it cools, moving away from the hotspot, further causing the island to sink

Three States of Water

-Hydrogen bonds help keep water molecules as a cohesive group at most temperatures found on Earth. This is why we have liquid water -The phases of matter are: liquid, gas, and solid-Ice is the solid form of water that is caused by subjecting water molecules to low temperatures -The gas form is experienced as water vapor (humidity is the amount of water vapor in the air) -Water vapor is formed when molecules of water escape the hydrogen bonds holding them together and become airborne (evaporation) -Water is the only substance on Earth that naturally exists in all three states

Ice

-Ice is less dense than liquid water due to all the air trapped in it. This is why ice floats -This is important for organisms living in areas where freezing temperatures are common, such as in the Arctic Ocean or around Antarctica -If ice did not float, a body of water would freeze from the bottom up and eventually the whole body of water would freeze -Since ice floats, the floating ice creates a barrier between the air temperature and the water below the ice, keeping it from freezing

Heat and Water

-In addition to hydrogen bonds, water has other unique chemical properties. One is a high latent heat of melting -Water has a higher latent heat melting than any other commonly occurring substance -This means that ice melts at relatively high temps and it absorbs a great deal of heat as it melts -Water also absorbs a great deal of heat before its temp rises -This property, known as heat capacity, is defined as the amount of heat required to raise a substance's temperature by a given amount -Water has one of the highest heat capacities of any naturally occurring substance -This high heat capacity is most important for marine organisms because it means they are not subject to the wide temperature ranges often seen on land. One exception is very shallow water, which warm up quickly due to relatively small volume of water -A great deal of heat is also required for evaporation to occur -The amount of heat required for a substance to evaporate is known as the latent heat of evaporation -Water has the highest heat of evaporation of any naturally occurring substance

Hybrid Thermoregulation

-Kleptotherms: Form of thermoregulation by which an animal shares or steals the body heat of another animal -Heterotherms: Animals except birds and mammals; having body temperature that varies with the environment -Facultative heterothermy (torpor): A physiologic state characterized by episodes of reduced BMR and low body temperature in response to low ambient temperature. -Gigantothermy/ectothermic homeothermy/homeothermy: A phenomenon with significance in biology and paleontology, whereby large, bulky ectothermic animals are more easily able to maintain a constant, relatively high body temperature than smaller animals by virtue of their smaller surface-area-to-volume ratio -Regional endothermy: The ability of some fish lineages to maintain certain body areas at higher temperatures than the surrounding water by means of vascular countercurrent heat exchangers or specialized thermogenic organs

Gases in Seawater

-Many gases are also dissolved in water: oxygen, carbon dioxide, nitrogen -Gases from the atmosphere dissolve at the sea surface. Occasionally, the reverse happens -Many organisms in the ocean utilize oxygen and release carbon dioxide Conditions Vary -Conditions at the ocean floor, in the water column, and at the surface vary greatly -Oxygen content, temperature, salinity, and other factors are often very different from one depth to another -Pressure also increases with depth. Water at the bottom has the weight of the water above it pushing down on it. Organisms living at these depths experience this amount of pressure Surface Circulation -Some of the differences seen in different parts of the ocean are due to circulation patterns -Circulation can occur in the form of waves, tides, currents, and gyres -Oceanic circulation is significantly driven by wind patterns-Winds are ultimately driven by sunlight energy

Energy and Life

-Many organisms use sunlight to drive the process of photosynthesis -In photosynthesis, plants, algae, and other autotrophs use pigments to capture the energy in sunlight -This energy is used to build carbohydrates -The source of carbon for building carbohydrates is carbon dioxide; oxygen is released as a by-product Cellular Respiration -Whether an organism makes its own carbohydrates (autotrophs) or gets carbohydrates by eating other organisms (heterotrophs), they must still break down the carbohydrates within their cells for energy -This process is called cellular respiration -Respiration uses oxygen and produces carbon dioxide and water as by-products Production -When these autotrophs make more energy than they can use, the excess net increase in organic matter is called primary production -Organisms responsible for this primary production are called primary producers -Marine organisms are a major source of worldwide primary production Nutrients -Marine organisms require nutrients to convert carbohydrates to other types of molecules -These nutrients include inorganic compounds like phosphates and nitrates (fertilizers) and also elements -Example: Silica is required to make the shell of some organisms

Matter and Nature of Water

-Matter consists of elements, each of which naturally occurs as small units known as atoms -Atoms can be found alone (such as atoms of helium) or they can be bound to other atoms in molecules -Molecules are the result of two or more atoms bonded chemically -In the water molecule, H2O, there are two atoms of hydrogen and one atom of oxygen chemically bonded together Unique Nature of Water -Each water molecule has slight positive and negative electrical charges -The positive charges are near the hydrogen atoms and the negative charges exist around the oxygen atom

Marine Dinoflagellates

-Most species are marine; mostly photosynthetic, some can ingest particles; each species has a particular shape, reinforced by plates of cellulose; two flagella in grooves for motion; some are bioluminescent -Zooxanthellae are important dinoflagellates that live in a symbiotic relationship with reef corals, some sea anemones, and other organisms; many of these host organisms have little or no growth without zooxanthellae Algal Blooms -Diatoms and dinoflagellates can go through periods of rapid growth known as blooms -This is a result of high levels of nutrients in the water. These blooms can be harmful to marine organisms and even humans at times Red Tides -A few species lack chloroplasts and live as parasites in other marine organisms -Some species can reproduce in larger numbers and produce red tides -Pfiesteria is a dinoflagellate that produces very serious toxins that can cause massive fish kills, harm shellfish, and impair the nervous system in humans Other Marine Protists -Groups of Marine Photosynthetic Plankton: 1. Silicoflagellates - star-shaped internal skeleton of silica, with two flagella of varying lengths 2. Coccolithophorids - ornate shells of calcium carbonate plates

Convergent Plate Boundaries: Continental Crust - Continental Crust

-Mountain chain in continental interior ("suturing") -Central core of granite flanked by metamorphic belt (ductile deformation) flanked by folded and faulted sedimentary rocks (brittle deformation) -Ocean crust slivers trapped in collision -Example: Himalayas mountain range

Marine Viruses

-Non-cellular infectious agents -Not capable of reproduction without a host cell -Structure: 1. Nucleic acid core: DNA or RNA 2. Capsid (protein coat) - consists of numerous protein subunits organized into rod-like or many-sided shapes Notable Types of Viruses -Retroviruses - store genetic information in the form of nucleic acid known as RNA -Lysogenic viruses - reproduce by inserting their DNA into the DNA of the host cell -Bacteriophages - viruses that infect bacteria -Common in the marine environment -Can infect marine bacteria, plankton, seaweeds, plants, and animals -Lysis (bursting) of cells infected with viruses spills contents and releases large amounts of organic matter than can be utilized by other organisms (dissolved organic matter) Prokaryotes

Marine Diatoms

-Photosynthetic; yellow-brown in color (photosynthetic pigments, chlorophyll a & c, and carotenoids); shell of silica called a frustule; most important primary producer on Earth; mostly solitary & unicellular; some can form colonies -Around half of the 12,000 known species are marine and most are planktonic -They store excess energy as an oil that also aids in buoyancy -Tiny pores in their shells are used for gas/nutrient exchange -Some produce a toxin, domoic acid, that can accumulate in the tissues of organisms that eat diatoms such as shellfish and small fishes -Mainly reproduce by cellular division (asexual reproduction); in this type of reproduction, the cell divides and each resulting cell gets one-half of the frustule -This cell now must secrete the other half of the frustule. Diatoms get smaller each time they reproduce -To restore normal size, they must either reproduce sexually or cast off the frustule and secrete an entire new frustule

Mechanisms Dolphins Use for Diving

-Rapid breathing prior to dive (apneustic breathing) -Lungs remove 90% of O2 from air (as opposed to 20% for humans) -Elastic tissue in lungs helps temporarily expand lungs during apneustic breathing -Marine mammals have more blood than non-diving mammals for their size (means more hemoglobin to carry oxygen) -Muscles contain more myoglobin to hold oxygen in tissues -The heart rate slows dramatically during a dive (bradycardia) -Blood flow is reduced to extremities and digestive system -Muscles employ anaerobic respiration as necessary (needs less O2 but results in lactic acid build-up) -Marine mammals can tolerate more lactic acid than other mammals -Rib cage and lungs collapse during dive to force air into tissues and prevent decompression sickness (bends)

Groups of Cnidarians

-Sessile Anthozoa (corals, sea anemones, sea fans) are single or colonial polyps that lack medusa. -Swimming Scyphozoa (true jellyfish) - Move by rhythmic muscular contractions. -Cubozoa (box jellyfish) - tentacles with nematocytes (stinging cells) -Hydrozoa (Siphonophores) - A collection of specialized individuals that form colonies and are genetically identical. More specifically, they are made up of discrete multi-cellular animals known as zooids and are connected by tissue. They reproduce asexually through budding. The Portuguese man o'war is a siphonophore and not a jellyfish.

Sonar

-Sonar (Sound Navigation and Ranging) was developed for the growing threat of submarine warfare -It is based on underwater echoes. -The time it takes between sending and receiving the "echoes" can be used to develop nautical charts, which are maps showing the shoreline and seafloor layout

Echolocation

-Sound waves are emitted as a series of clicks of varying frequencies -Melon directs the outgoing sound waves -After the echo strikes an object, it is reflected back -These reflected echoes are received back by the melon and lower jaw -The longer it takes a echo to return, the farther away the object is located -Characteristic of toothed whales.

What is homeostasis?

-The Greek word for "same" and "steady." -The organisms use self-regulating processes to maintain the stability and uniformity of internal, chemical, and physical conditions. -Organisms need to maintain homeostasis to survive; therefore, the organism will adjust to optimal conditions for its survival. -Examples of self-regulating processes include thermoregulation, osmoregulation, chemical regulation, oxygen homeostasis.

Ocean's Earliest Navigators

-The Phoenicians were the first accomplished Western navigators -Greek philosopher Aristotle is considered to be the first marine biologist (He described many forms of marine life and recognized that gills are the breathing apparatus of fish) Ben Franklin during the mid-late 1700s, navigated the North Atlantic ("Maritime Observations" and description of the Gulf Stream) James Cook -First to make scientific observations. He went on 3 voyages -First to use a chronometer -Reshaped the European conception of the world -First to include a full-time naturalist among his crew Charles Darwin -Started in 1831, sailed on the HMS Beagle for 5 years -This voyage contributed to proposing the theory of evolution -The main goal of the expedition was to map reef and coastlines -In 1842, he his theory on how coral atolls form

Plant vs Animal Cells

-These cells have many of the same organelles -However, plant cells contain a cell wall, chloroplasts, and vacuoles. While animals cells don't have these organelles

Polar Bear (Order Carnivora)

-Ursus maritimus -Largest land carnivore -Spend part of their life on drifting ice in the Arctic Ocean: threatened by decreasing ice -Thick fur coat that appears white in coloration, but is really translucent -Smaller ears and longer necks than other bears (adaptations to low Arctic temperatures) -Adult males larger than adult females -Adult polar bears need an average of 2 kg (4.4 lb.) of fat per day to maintain their weight. Diet includes mostly ringed and bearded seals but also other seal species, walrus, narwhal, beluga whale, whale carcasses, fishes, birds, eggs, berries, and kelp -Gestation of about 8 months, including about 4-month delayed implantation; lactation of cubs for about two years

Water Density

-Water molecules move closer to one another with lower temperatures -In a gallon bucket of seawater at 75 F, the molecules are further apart than when this same gallon of water is at 35 F -When molecules are closer together, the substance is said to have a greater density -Substances with higher density are heavier than those with lower density when the same volume is present -Cold water therefore sinks underneath the warmer water -Cold water also holds more oxygen than the same volume of water, a crucial factor for organisms living at the ocean floor -Even though colder water is more dense than warmer water, this changes when the water gets cold enough to freeze

Waves

-Waves are the result of wind blowing over the water's surface -The size of the waves depends on how long and fast the wind blows: longer and faster equals a larger wave -The size of waves is also larger when the fetch, the amount of open water a wind blows over, is larger -The highest point of a wave is the crest, the lowest point is the trough-The distance between two crests (or two troughs) is the wavelength -The time it takes for a wave to pass by a set point is the wave period -As waves near the shore (shallower water), the bottom of the wave "drags" the bottom -This forces the waves to slow and move closer together (shorter wavelength) -Eventually, the drag causes the wave crest to fall over - we call this a wave break. The surf caused from breaking waves can displace a lot of and, which affects the organisms living there

Marine Mammals Behavior

-Well known for their vocalizations such as the "barking" of sea lions and "songs" of the humpback whale -Engage in play behavior regularly, including sexual play -Large brains: great ability for learning new behaviors -Breaching: many species jump out of the water and crash back into the water on their backs -The reasons for this behavior: removing parasites, a warning signal, to avoid suitors, or just to play -Some whales show spying behavior -Many whales are known for their long migrations -Among the longest migrations are those of the gray and humpback whales, where migrations are timed with feeding in cold water and breeding in warm water Complex Behaviors -When one member of a group (pod) is sick or injured, other members will care for it -Mass strandings are often the result of caregivers following a sick/injured animal to shore -Maternal care of young

Order Cetacea

-Whales, dolphins, and porpoises -Fore limbs are modified into flippers -Fin-like tail (fluke) -Nostrils are located on the top of the head as a single or double opening (blowhole) -Baleen whales (Suborder Mysticeti) - baleen for filter feeding, two blowholes, smaller size -Toothed whales (Suborder Odontoceti) - teeth, single blowhole, larger size

Modes of Reproduction

Asexual Reproduction: -Does not involve the mating of two individuals -Offspring are produced by a single parent individual -Offspring are therefore genetically identical (clones) of the parent Examples of Asexual Reproduction -Fission - the splitting of one organism into two smaller organisms of equal size -Budding - the organism develops buds (small clones) that eventually break off and become another organism -Vegetative reproduction - a plant reproduces new individuals by sending an underground stem (rhizome) sideways from which new plants will sprout Sexual Reproduction: -Normally involves two individuals -Parents produce gametes (eggs or sperm) that unite (fertilization) to produce a new, genetically unique individual different from either parent (ovaries - organs that produce eggs; testes - organs that produce sperm) -Many marine organisms release their eggs and sperm directly into the water, known as broadcast spawning -For broadcast spawning to be effective, millions of gametes must be released into the water at roughly the same time to ensure fertilization will occur -Many broadcast-spawning species time the release of their eggs to tides, moon phase, water temperature, etc. to ensure success -Other marine organisms rely on internal fertilization, where a copulatory organ inserts sperm directly into the female's reproductive tract -This method requires contact between the parents, but less gametes are required for success -Hermaphrodites - individuals that have male and female reproductive tissue/organs either simultaneously or at different phases during their life

Baleen Whales and Toothed Whales

Baleen Whales: -Baleen whales have rows of flexible, fibrous plates known as baleen that hang from the upper jaws -Filter feeders: Take in huge mouthfuls of water containing krill or small fishes. The baleen traps the prey, and water is forced back out of the mouth -13 species, including the right, gray, blue, and humpback whales Toothed Whales: -Simple, peg-like teeth, which vary considerably in number and size among species. Dolphin teeth are conical and interlocking, those of porpoises are spade-shaped. Teeth are adapted for grasping and tearing, not chewing -Diet: fishes, squids, bottom invertebrates -Include dolphins, porpoises, belugas, narwhals, sperm, orcas (killer whales), river dolphins, and beaked whales -Many threatened with extinction as a result of whaling Whale Behaviors: Whales may be identified from their fluke shape, blow pattern, or view of back when starting a dive

Differences between continental and ocean crust

Basalt Andesite Granite Fe, Mg - rich ------> Fe, Mg - poor Silica - poor -------> Silica - rich More dense -------> Less Dense Oceanic Crust -----> Continental Crust

Comb jellies (Ctenophora)

Basic Characteristics: -8 rows of ciliary combs that beat continuously -Radial symmetry -No nematocysts -Long sticky tentacles used to capture prey -About 100 species, all marine, mostly planktonic

Marine Reptiles

Basic Characteristics: -Air breathing: presence of lungs -Mostly "cold-blooded" (ectotherms, poikilotherms) -Body covered with scales -May lay their eggs on land Four groups of marine reptiles: sea turtles, sea snakes, marine iguana, saltwater crocodile and American crocodile

Sponges (Porifera)

Basic Characteristics: -All are sessile (attached), some encrusting on hard substrates -Numerous tiny pores (ostia) allow water to pass through the body for filter-feeding on plankton and organic matter in the water -Water flow also carries waste and gametes away -Mostly marine -Asymmetrical body plan with no tissues or organs: colony of different types of cells Types of Sponge Cells: -Collar cells (choanocytes) - line interior canals, flagella create a water current that brings in food particles, collar on choanocyte traps food particles -Pinacocytes - flattened cells that cover exterior of body -Pore cells (porocytes) - cells with a pore to pass into body Structural Support: -Spongin - support protein -Spicules - support structures made of silica or calcium carbonate. Spicules have a variety of shapes from simple rods to stars Reproduction: -Asexual budding - buds break off and grow into a new sponge -Sexual - sperm are released into the water (broadcast spawning) to be picked up by a nearby sponge and directed to an egg -Most sponges are hermaphrodites (produce both sperms and eggs)

Cnidarians (Cnidaria)

Basic Characteristics: -Radial symmetry -Mostly marine, about 10,000 species known -Two body forms: 1. Medusa - free-swimming form that is transported by water currents, mouth with surrounding tentacles positioned downwards 2. Polyp - attached form with mouth and tentacles positioned upwards -Two tissue layers: 1. Epidermis covers body surface 2. Gastrodermis lines internal body cavity; specialized for digestion -Nematocytes (stinging cells) within specialized cells (cnidocytes) on tentacles. Used for protection and feeding -Digestive system is incomplete (sac-like with the mouth only) -Nerve net throughout body coordinates movements -Some jellyfishes also have sensory cells and contractile cells Reproduction: -Sexual 1. In some cnidarians: medusa is the sexual stage, releasing eggs and sperm 2. Fertilized egg results in a zygote, which develops into a swimming larva, the planula3 . The planula settles on the bottom to form a colony of polyps 4. New medusae are formed by a mature colony -Asexual 1. Polyps reproduce by budding

Hemichordates

Basic characteristics: -Benthic organisms; divided into two groups - enteropneusta (individual) and pterobranchs (form colonies) -Share some features with chordates (our phylum), including pharyngeal gill slits and a hollow dorsal nerve cord -Include the acorn worms, deposit feeders that use a proboscis for feeding Examples of Hemichordates: -Enteropneusta (acorn worms) - solitary, unsegmented organisms; benthic -Pterobranchia is very different from Enteropneusta in that they form colonies that comprise individual interconnected organisms (zooids); living in secreted tubes; benthic

Building Blocks of Life

Carbohydrates -Made of carbon, hydrogen, oxygen in a 1:2:1 ratio -Most carbohydrates are used for energy -Some are used to store energy to be used later -Some are used as structural molecules like cellulose (found in plants) and chitin (found in the shells of some animals like crabs and lobsters) Proteins -Composed of smaller units known as amino acids -Enzymes are specialized proteins essential to carry out chemical reactions in organisms -Some proteins are hormones that act as chemical messengers within an organism -Others can be used as structural molecules (like in muscles) and many other important functions Lipids -Most lipids do not mix with water -As a result, many marine organisms use a coating of lipid to cover outer surfaces, fur or feathers, which provides an insulating layer -Some, like most marine mammals, also have a layer of lipid (fat) underneath the skin for the same purpose -Lipids (fats) also provide buoyancy -Many lipids are used for energy storage within an organism Nucleic Acids -DNA and RNA are nucleic acids -Made of particular arrangements of four smaller units called nucleotides -The genes are messages contained in DNA -DNA is the molecule of heredity; it provides the instructions for making proteins -RNA also helps with this duty

Arthropods and Crustaceans

Characteristics of Arthropods - jointed legs and other appendages; exoskeleton made of chitin; segmented body divided into a head, thorax, and abdomen Characteristics of Crustaceans: -Crustaceans (barnacles, isopods, shrimps, lobsters, crabs) - gills are present, Head and thorax fused as a cephalothorax and usually covered by a carapace; open circulatory system -Male transfers sperm directly to female to ensure reproductive success -Some are filter feeders, others scavengers, parasites, carnivores Examples of Crustaceans: -Copepods - planktonic; they are generally the most dominant zooplankton at all depths; primary consumers -Barnacles - rigid calcium plates; sessile; modes of reproduction -Lobsters, shrimps, and crabs - decapods (10 legs); feeding; complete digestive system (shrimps are more complex); possess a gastric mill that grinds food because they don't have teeth; feeding mechanisms

Invertebrate Chordates

Characteristics of Invertebrate Chordates - lacks a backbone; considered a chordate because, during the embryo or larval stage, they possessed a hollow dorsal nerve cord, a notochord, post-anal tail, and gill slits along anterior half of pharynx. Examples of Invertebrate Chordates: -Tunicates (sea squirts or ascidians) - only tadpole larvae have chordate characteristics; however, adults still have pharyngeal slits; many are poisonous; most adults are sessile; can be planktonic (salps or sea grapes) that use jet propulsion -Lancelets (amphioxi) - have all the chordate features as adults; benthic organisms spending most of the time half-buried sand in shallow marine environments or tropical seas; fish-like body but does not have a backbone

Molluscs (Mollusca)

Characteristics of molluscs - body plan comprises of a head, muscular foot, a visceral mass that holds a bulk of the vital systems; a nervous system with a brain; complete digestive system; open circulatory system; most have a radula which is an anatomical feature that functions as a tongue. Example of Molluscs: -Gastropods (snails, limpets, sea slugs) - siphons that are used to "smell" or "taste" water to hunt food. -Bivalves (clams, oysters, scallops, mussels) - body compressed between two shells of valves; gills for filter-feeding and respiration; have siphons; does not have a radula. -Cephalopods (squids, cuttlefishes, chambered nautilus) - uses muscular mantle cavity to take water through the gills expel water out of the siphon, creating jet propulsion. -Chitons - flattened and elongate, eight overlapping dorsal shell plates or valves; most live in the rocky intertidal zone or just below the low tide level; an encrusting organism that; uses the radula for grazing on algae by scraping rock substrates.

Pinnipeds (sea lions, fur seals, and seals)

Characteristics: -Predators, feeding mostly on fish, squid, shellfish -Breed on land and return to sea after giving birth Implantation of the embryo is delayed in many species so that the birth of the calf is timed with the return of females to land -Prefer breeding near shallow water and abundant food -Mostly living in cool or cold water; the presence of blubber helps to maintain the internal body temperature -Monk seals are the exception: Hawaiian and Mediterranean monk seals are endangered; Caribbean monk seals have not been seen since the 1950s -Fore and hind limbs adapted as flippers for swimming -35 species

Coriolis Effect and Trade Winds

Coriolis Effect -Both winds and currents are affected by the Coriolis Effect -Because the Earth spins continuously, anything that passes over the Earth is deflected -In the Northern Hemisphere, winds and currents are deflected to the right -In the Southern Hemisphere, winds and currents are deflected to the left -Since the Earth is spinning, it causes this deflection of winds and currents -This deflection often causes currents to travel in circular patterns called gyres Trade Winds -As sunlight heats air, air rises -Cooler air rushes in to take the place of air that has risen -This movement is the source of winds -Winds at the coast are stronger during the day then at night as a result of the presence (or absence) of solar energy -Winds that are continuously created in this manner at the Equator are known as the trade winds -The westerlies in mid latitude and the easterlies closer to the poles are less consistent than the trade winds

Other Ocean Expeditions

D/V Glomar Challenger (1968-1983): -One of the most important discoveries was continental drift and seafloor spreading evidence. -The age of the ocean seafloor was also determined using samples from this expedition D/V JOIDES Resolution (1985-present): -Research vessel that drills into the ocean floor for scientific research -Named after the HMS Challenger, which was commanded by James Cook D/V Chikyu (2005-present): -Japanese scientific drilling ship -World's first riser drilling-equipped science vessel -Drilling up to 2,500 m -The ultimate goal is to drill to the Earth's mantle and seismogenic zone

Three-Layered Ocean

Despite repeated mixing by winds and surface currents, the ocean is stratified into three layers: -Surface layer - from surface to about 200 m; this layer stays well mixed most of the year -Intermediate layer - from 200-1500 m; a sharp temperature change (thermocline) is located here. Less mixing here -Bottom layer - below 1500 m; low mixing and normally uniformly cold -In some locations, large volumes of water may sink or rise -Water sinks due to changes in temperature and salinity (downwelling) -Downwelling brings gases from the surface to deeper layers -Areas of upwelling come from currents that push deeper waters toward the surface -Nutrients are much more plentiful in the deeper layers, so areas of upwelling are beneficial for surface organisms

Evolution, Natural Selection, Taxonomy, Species, Phylogenetics

Evolution -Is defined as a gradual change in the genetic makeup of a population over time. Individuals in a population have genetic differences in their ability to survive in the form of finding food, avoiding being eaten, surviving disease, producing offspring, and many other attributes Natural Selection -Is the process by which the best-adapted individuals are better survivors and more of their gametes, and their genes, will make it into the next generation. The less adapted individuals may not survive to reproduce or will reproduce less and thus pass less of their genes to the next generation -As a result of natural selection the gene pool of a species changes, or evolves, through time by eliminating less advantageous traits in favor of those that provide better survival: the gene pool changes as a result of pressure from the environment Taxonomy -Taxonomy is the science of classifying and naming the different species that have resulted from the process of evolution -This classification is done using different characters, which include internal and external body structures, DNA and protein analysis, the particular places where species live -Taxonomy uses several levels of classification, from the widest to the smallest (Domain --> Kingdom --> Phylum --> Class --> Order --> Family --> Genus --> Species) -Species are identified by the use of two names: the genus followed by the species epithet Species -A species consists of individuals that have many characteristics in common and the ability to breed successfully with each other, the biological species concept -When two populations can't interbreed, they are reproductively isolated from each other and therefore belong to two different species Phylogenetics - the study of evolutionary relationships between organisms -Biologists use many characteristics to determine the relatedness of organisms such as structure, DNA, fossils, reproductive patterns, embryological and larval development, habitat, and behavior

Feeding Habits and Reproduction of Sea Turtles

Feeding Habits: -Sea turtles feed on sponges, crabs, molluscs, and other invertebrates -Exceptions: 1. Green sea turtle - vegetarian (seaweeds, seagrasses) 2. Leatherback (largest of all sea turtles: up to 9 feet, 2000 lbs) - mostly jellyfishes but can dive to depths of at least 2000 feet in search of other prey Reproduction: -Sea turtles breed at sea: internal fertilization (copulation) -Females can store sperm -Once clutch (group) of eggs can have multiple paternity: males and females are not monogamous -Females normally breed every 2-4 years -Females must return to land to deposit their eggs above the high tide; they dig a hole in the sand using only their back flippers -During their breeding year, females may lay up to 7 clutches of eggs -Each clutch of eggs normally has more than 100 eggs -Eggs have a typical incubation period of around 60 days, although this varies according to air temperature -Warmer temperatures mean eggs will develop faster, colder temperatures lengthen the process -The eggs are leathery, gradually becoming more brittle, making it easier for the hatchlings to emerge -Sea turtles, like many reptiles, show temperature-dependent sex determination -The gender of the hatchling is not genetically predetermined but determined by the temperature in which the eggs are incubated -For each species, there is a temperature that will produce 50% males and 50% females; temperatures higher than this temperature will produce more females, lower temperatures more males

Marine Protozoans

Foraminiferans (forams): -Exclusively marine, non-photosynthetic (heterotrophs, thus animal-like) -Shells (test) of calcium carbonate -Can be important contributors of calcareous material on coral reefs or sandy beaches -Pseudopods extend through pores in the shell where they are used to capture minute food particles such as phytoplankton Radiolarians: -Planktonic, mostly microscopic -Shell of silica -Like forams, they use pseudopods that extend through pores in the shell and are used to capture minute food particles such as phytoplankton Ciliates: -Hair-like cilia for locomotion -Most live as solitary cells -Some build shells made of organic debris -May live on hard substrates but some are planktonic -Tintinnopsis is an example of a ciliate

Types of Seaweeds

Green Seaweeds (Green Algae): -About 7,000 species, mostly marine -Microscopic to macroscopic -Photosynthetic pigments: chlorophyll a and b as well as carotenoids -Store excess energy as starch -Cellulose in cell walls -Calcareous green algae - thallus with calcium carbonate Brown Seaweeds (Brown Algae): -About 1,500 species, almost all marine -Some microscopic, most larger (up to more than 100 m) -Prefer shallow, cold waters -Contain chlorophyll a, c, and fucoxanthin (brown photosynthetic pigment) -Examples: kelps, rockweeds, sargassum) -Kelps: found in temperature and polar locations; the largest of the seaweeds -In some species, like the giant kelp, each individual can be hundreds of feet in length -Kelp forests are among the most productive marine communities -High biodiversity of organisms associated with kelp forests -Sargassum is a brown seaweed that forms massive floating mats in the Sargasso Sea, a section of the Atlantic Ocean north of the West Indies Red Seaweeds (Red Algae): -About 4,000 species, almost all marine -Contain chlorophyll a, phycobilins, and other red photosynthetic pigments -Most species are found in warm and cold shallow water, but some can be found in relatively deep water -Coralline algae - thallus accumulate calcium carbonate (Ex: Corallina)

Growth and Destruction of an Ocean

Growth of an Ocean: 1. Embryonic: Uplift 2. Juvenile: Divergence (spreading) 3. Mature: Divergence (spreading) Destruction of an Ocean: 1. Declining: Convergence (subduction) 2. Terminal: Convergence (collision) and uplift 3. Suturing: Convergence and uplift -The first continents were island arcs -When subduction caused island arcs to collide, the arcs sutured together -These pieces of continental crust collided with others, growing continents by accretion.

Seaweeds

Important primary producers; often called marine algae or macroalgae; eukaryotic, mostly multicellular; lack leaves, stem, and roots of plants -Thallus - body of seaweed -Blades - leaf-like structures -Stipes - stem-like structures -Holdfast - root-like structures Seaweed Reproduction -Sexual reproduction by many seaweeds involve complex life cycles often consisting of different generations

Dugong and Manatees (Order Sirenians)

Manatees -Three species: -Trichechus manatus - West Indian manatee (Florida and West Indies); often enters freshwater waterways along coast -Trichechus senegalensis - the West African manatee); also enters freshwater waterways along coast Trichechus inunguis - Amazonian manatee (strictly fresh water) -Dugong (Dugong dugon) - East Asia to western Pacific islands -Front flippers but no rear limbs; paddle-like horizontal tail -Primarily herbivores (seagrasses, freshwater vegetation). Manatees consume about 4% to 9% (15 to 49 kg or 32-108 lb. for an average adult manatee) of their body weight in wet vegetation daily -Manatees may reach 4.5 m (15 ft), 600 kg (1,320 lbs) -All four species endangered or threatened, particularly dugong -Slow reproduction, mature after about five years and giving birth to a single calf every two to five years after a gestation period of about a year

Marine Iguana, Seabirds, Penguins

Marine Iguana: -One species found only on the Galapagos Islands -While they are called marine, they only spend a portion of their time in the water -They dive to feed on seaweeds and seagrasses near shore -A large portion of their day is spent basking on the shore to warm up from their dives in the cold water surrounding the Galapagos Seabirds: -Seabirds - birds that nest on land but feed exclusively or in part on marine organisms -Like mammals, seabirds are able to maintain a constant body temperature (homeotherms) derived through metabolic means (endotherms) -Feathers are coated with an oil from glandular secretions to waterproof the body -The hard-shelled egg provides more protection than the leathery shell of reptiles -Many species of seabirds nest in large colonies on cliffs, isolated islands, low shrubs or trees, or on the ground-Some species are monogamous and mate for life -Complex behaviors include rituals such as selecting a mate, protection of young, and long migrations Penguins: -Most radically adapted of all seabirds; flightless with flipper-like wings -Spend a great deal of their time searching for prey at sea -Most species live in Antarctica or sub-Antarctic regions -Adapted to cold water with a layer of fat and trapping of air in the feathers -Males and females share parenting responsibilities -Some penguins have been classified as 'heterotherms'. The temperature of their feet is close to that of the surrounding ice, which prevents their feet from freezing

Convergent Plate Boundaries: Ocean Crust - Ocean Crust

Ocean Crust - Ocean Crust -Ocean trench - deep linear depression where one plate slides under the other ("subduction") -Accretionary wedge - pile of deformed ocean sediment that is scrapped off subducting plate. -Volcanic island arc - forms by partial melting of subducting slab -Older (colder) denser crust sinks back into mantle (subduction). -It starts to partially melt at a critical depth. -Magma is intermediate in composition: this is where some continental crust is created. -Oceanic volcanoes, if they build up tall enough, become islands. -Because of the curvature of the Earth, the subduction zone, and the chain of islands, is arc-shaped: island arcs. -Examples: the Philippines, the Caribbean Islands, Japan, the Aleutian Islands, Indonesia.

Types of Organisms

Prokaryotic Organisms -Cells lack a nucleus, absence of most organelles in cells, cells contain a circular ring of DNA, cell wall is normally present, unicellular (single-celled) Eukaryotic Organisms -Cells with DNA enclosed inside a nucleus, cells possess many specialized organelles, these organisms can be unicellular or multicellular Organelles in Eukaryotic Organisms -Nucleus - contains the chromosomes, which contain the DNA -Mitochondria - site of cellular respiration -Golgi complex and endoplasmic reticulum - manufacture, package, and transport cellular products such as proteins -Ribosomes - site of the manufacture of proteins -Chloroplasts - site of photosynthesis -Vacuoles - storage of water and nutrients

Marine Flowering Plants Continued

Salt-Marsh Plants: plants bordering shallow bays and estuaries at the mouth of rivers -Cordgrass (Spartina) is the dominant salt-marsh plant in many salt marshes -Exposed to saltwater at high tide; salt glands help deal with excess salt -Important as habitat to many marine animals including juvenile invertebrates and fishes -Detritus from cordgrass is a nutrient for countless organisms -Other halophytes (salt-tolerant plants) grow in areas of higher elevation than cordgrass Mangroves -About 80 species of mangroves live only in tropical and subtropical areas of the world -They can't withstand freezing temperatures -They can only tolerate partial saltwater submergence -Many mangroves have prop roots that are exposed at low tide -Seeds of mangroves germinate while still attached to the parent plant and develop into seedlings before falling into the water -Seedlings drop into nearby soft sediments or are carried by water currents to new locations -Mangrove forests, or mangals, are highly productive communities that provide habitat to many marine and land organisms -They are the tropical equivalent of salt marshes

Sea Otters, Marine Otters (Order Carnivora)

Sea Otters: -Fine, dense fur coats for insulation, no blubber -Smallest true marine mammal, with anterior feet small with retractile claws; posterior feet broad and webbed -Metabolic rate higher than most mammals of similar size so must consume large quantities of food. Adult sea otters may eat as much as 9 kg (20 lb.) of food each day: sea urchins, crabs, abalone, clams, mussels, octopuses, and fishes -Three subspecies, or races, of Enhydra lutris (small differences in size, amount of time spent on land): Asian (northern Japan and Siberia), Alaskan, California -Typically found in waters close to shore. The Alaskan sea otter has a greater tendency to come to shore than the California sea otter Marine Otters: -Lontra felina -Spends most of the time on rocky shores but feeds on small marine invertebrates -Pacific coast of temperate South America -Endangered because of hunting and habitat loss

Sea Snakes, Saltwater Crocodile, American Crocodile

Sea Snakes: -Laterally flattened body with a paddle-like tail for propulsion through the water -70 species of sea snakes -Found only in the Indian and Pacific oceans -Most species are 3-4 feet in length as adults -Breed at sea; most species are ovoviviparous. A few species still return to land to lay eggs -Carnivorous and mainly feed on fishes and fish eggs -Bites from sea snakes can be fatal for humans (sea snakes are related to the cobra and have a powerful venom), but sea snakes are not known to be aggressive and have small mouths -Most species are ovoviviparous, where the eggs hatch in the body of the parent Saltwater Crocodile: -Found in Australia, the Indian Ocean, and some Western Pacific Islands -It can be found in estuaries, mangrove forests, rivers, and the open ocean -It is a predatory species that eats all types of prey, including humans -Reaches up to 30 feet (although individuals over 20 feet are rare) American Crocodile: -Considered a marine species because it tolerates seawater and can be found in lagoons and other coastal regions -Widely distributed in Florida, the West Indies, and Pacific and Atlantic coasts of Central America and northern South America -Males have been recorded as long as 20 feet but average is 14 feet-Feed mostly on fish

Types of Symbiotic Relationships

Symbiosis = living together -Members of different species living in very close association -This close ecological relationship is between two individuals of two or more different species -Smaller partner is usually called a symbiont, and the larger are the host 1. Mutualism - both species benefit from the relationship 2. Commensalism - one species obtains shelter or some other benefit without impacting the other species 3. Parasitism - the symbiont benefits at the host's expense 4. Competition - neither species benefits because both are competing for the same resources. Can in intraspecific (same) or interspecific (different) 5. Predation - one species benefits while the other dies 6. Neutralism - the species do interact with each other but do not affect each other

What is the scientific method?

The procedure that scientists use to learn about the world 1. Observation - At the heart of the scientific method is the conviction that we can learn about the world through our senses with tools that extend our senses 2. Predictions -Induction: They use observations to arrive at general principles -Deduction: Scientists start with a general statement about nature and predict what the specific consequences would be if that statement is true 3. Formulate a Hypothesis: Scientific hypotheses must be stated in a way that allows them to be critically tested. It must be possible to disprove the hypothesis if it is false and test it 4. Testing a Hypothesis: Scientists spend their time trying to disprove hypotheses. Often scientists are trying to decide amount two or more alternative hypotheses. Variables that are prevented from affecting an experiment are said to be controlled. 5. Reject the hypothesis if it fails, test it again if it does not 6. If it never fails, assume it is the truth Limitations of the scientific method: -Science can't make judgements about values, ethics, or morality -Scientists can't be completely objective at all times