OCE1001 Exam 3 Study Guide
What is the scientific evidence for human causation of global warming?
- 'Hockey stick' curves (temp., CO2) - Match of atmosphere CO2 concentration and fossil fuel use - Change in chemistry of atmosphere CO2 in atmosphere since fossil fuel use - Models show change in temperature can only be explained by CO2 increase - Since the 18th century, record of CO2 concentration in atmosphere matches record of fossil fuels burning - Since the 18th century, carbon chemistry (isotopic ratio) of atmosphere CO2 has changed reflecting an progressively older C source (fossil fuels). - Change in temperature can only be explained by CO2 increase - The only quantitative and internally consistent explanation for the recent global warming is the intensified greenhouse effect caused by the increase in CO2 and other greenhouse gases. - 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC)
What are the major uncertainties in global warming science?
- Climate sensitivity (modeling) - Projections of global air temperature due to thermal inertia i.e. no future CO2 emissions = additonal increase of 0.4 - 0.7 oC by 2035, IPCC, 2013) - Future human emissions - Other drivers of global climate change (feedbacks) - Natural: e.g. volcanic eruptions, solar variation. Human: land-use change, aerosols - Carbon cycle response to warming (feedbacks) - Regional/Local climate responses -Warming likely greatest over land, and in polar region. Generally, wet areas get wetter, dry areas get dryer. - Effects
Why are reefs biodiverse?
BIODIVERSITY bc Many potential niches (specialization) Complex structure Stablity?
Chemotrophy
Bacteria get energy from oxidizing simple inorganic chemicals (sulfate, ammonia...) CO2 + seawater chemicals + energy = organic matter
Algae
- chiefly aquatic -Includes prokaryotes (Bacteria and Archaea), single-cell eukaryotes (Protists), multi-cellular plants -without true stems, roots and leaves -typically autotrophic, photosynthetic, -contain chlorophyll -may be free or attached to structures -food for everything: fish and small aquatic animals
What's the difference between Biological Oceanography and Marine Biology?
Biological Oceanography - the ecology of marine organisms (interaction with physics, chemistry, and geology of the ocean environment) Marine Biology - the biology of marine organisms: (physiology, behavior, feeding biology, biochemistry, reproduction)
What are the main features of coral reefs? (Where found? Why important?)
Biotic Reef: a biological structure. Examples: oyster reef, coral reef like forest trees, reefs provide both habitat & high primary production, high biodiversity Only 0.2% of sea area but house 30% of marine species most biodiverse ecosystem on the planet Provide Services: coastal erosion protection, tourism, fish nursery, pharmaceuticals Most complex and biodiverse marine systems FOOD SOURCES Sponges are food for nudibranchs, sea stars, turtles, fish Parrotfish actually eat the reef (algae) FEEDING STRATEGIES filter feeders: coral, sponges, sea anemone, feather stars, sea squirts and salps, giant clams predatory: sharks, rays, groupers, sea stars scavengers & detritavores: crabs and sea cucumbers cleaners: wrass, goby Oldest marine communities, > 500 m.y. Restricted to warm waters (23-29°C optimal) Found in clear nutrient-poor water. More common and diverse in the Pacific (Indo-Pacific coral reefs have as many as 700 or so species of corals present, along with perhaps 3,000 kinds of reef fishes.)
What two organisms make up coral and of what benefit are they to each other?
CNIDARIA AND DINOFLAGELLETS Phylum: Cnidaria Reefs made up of individuals (colony of polyps) possessing tentacles with nematocysts to capture prey Polyps secret calcium carbonate exoskeleton (Inside the body of the polyp are digestive and reproductive tissues. Growth varies from about 0.5-3 inches per year Most contain symbiotic algae: zooxanthellae (dinoflagellate: Protists: single cell algae, genus Symbiodinium) Photosynth. provides O2 and organic matter to dioflag. and aids CaCO3 precipitation by removing CO2 Cnidaria provide shelter & nutrients for algae in zooxanthellae AND support to stay in light The symbiosis is successful but vulnerable: - In some corals the zooxanthellae produce up to 60% of the coral energy needs. Need right & stable temperature Need right light (no suspended sediment or algae)
What is ocean acidification? Causes? Impacts? Potential solutions?
CO2 dissolves in water, then chemically reacts forming H+ corals, algae, shellfish and mollusks difficulty forming CaCO3 shells and skeletons - shells become pitted and dissolve -Fish most susceptible to acid/CO2 when in egg or just hatched acidification affects different organisms in different ways -threatens many organisms at the bottom of the food chain...could trigger domino effect through ecosystem Could cause a Global Mass Extinction - Ocean acidification may have played a major role Permo-Triassic die-off of 90% of Earth's species - acdification rate now is faster!
Overfishing
Catching more fish than a system can supply catching so many adult fish that the breeding population cannot replenish themselves, i.e. population size decreases. non-sustainable fishery practices
What caudal fin adaptations have been made for different fish 'lifestyles'?
Caudal fins provide the primary thrust for most fishes Increasing the size of the caudal fin should increase speed but this also increases drag High aspect ratios maximize thrust and minimum of drag for high cruising speed, but limits maneuverability Low aspect ratio maximizes drag for the thrust: for high maneuverability with short bursts of speed (but low speed)
Bycatch (Bykill)
Caught along with target catch (discarded catch plus incidental catch)
What are some common arguments against global warming and how can these be countered?
Climate is always changing. Earth has been warmer in the past ...such as during the Cretaceous Period. BUT A predicted global temp. rise of 4 oC by 2100 would make it warmer than Earth has seen in the past 40 m.y. Global warming has stopped 16 years ago. BUT This is only for surface atmosphere temps. Ocean still warmed. Always have these periods of stasis. Too short of a time period to be significant.
Marine Adaptation for Cold
Cold blooded - most marine animals Internal temp = external temp Don't have to expend energy heating Tend to move in short quick bursts Have special enzymes that operate at lower temperatures Fish: Heat generated by swimming muscles retained by specializations of the circulatory system Marine algae have special fats that remain liquid at low T (unsaturated..with double bonds e.g. omega-3) Warm blooded - more complex animals: mammals (some fish) Stable, high internal temperature Advantage: Can move, eat, reproduce faster Insulating layer of fat (blubber) keeps body warm and buoyant dense layer of hollow fur traps a layer of air next to the skin so skin never gets wet. Large size: Reduces surface area to volume ratio, less heat loss to surroundings Controlling of blood circulation: Vasodilation controls where and when blood goes Countercurrent heat exchange in limbs allows cold blood returning to the body core from extremities to be warmed by exchanging heat with closely packed arteries going to the periphery.
Most abundant animal?
Copepods
What is coral bleaching? What causes it?
Coral bleaching: Under stress, corals may expel their zooxanthellae, causes a lighter or completely white appearance...if prolonged, followed by death of polyps. Increasing in recent years : 80% of coral in the Caribbean and 50% in Indonesia and the Pacific have been destroyed - 90% in western Indian Ocean - 60% in Great barrier Reef - Globally about 1% of coral is dying out each year - At present rate, 50% will be gone in 40 y POSSIBLE CAUSES (probably stress causes by multiple of these): Water too warm (1-2o) (global warming?) Ocean acidification Solar irradiance (due to loss of ozone?) Disease (pathogen) Pollutants (nutrients, sediment) Overfishing
What is primary production?
Creation of biomass from inorganic compounds (CO2 Organic C) Is the base of any food chain Making organic matter from inorganic matter CO2 + nutrients organic matter
Know the classification system for Linnaean taxonomy
Domain Kingdom Phylum Subphylum Class Order Family Genus Species
What are the major fishing techniques used in the fishing industry?
Driftnets- notorious for their bykill of turtles seals dolphins etc Trawling- conical nets drawn through the water at surface mid or bottom (highly disruptive of benthic environment) -Shrimp trawling is smaller but still very wasteful -Killed lots of turtles: TED (turtles excluder device) Purse seine: net is released behind boar, usually in a circle several hundred meters across -Two net ends are brought together -Catches everything Long-lining -Less bycatch -Thousands of bated hooks -Catches sharks birds and mammals -Almost half thrown back
What are the major benefits and problems related to aquaculture?
Environmentally okay for shellfish Coastal fish aquaculture problems: -nutrient pollution -requires food sources that are commonly marine -high concentrations of single species are subject to rapid spread of disease. -genetic dilution -Habitat destruction (Asian mangrove forests) mangrove forests (important ecosystem) destroyed to make ponds fed protein pellets and artificial feeds antibiotics, pesticides and detergents added releases wastes that degrade surroundings causes saltwater intrusion at surrounding farms
What is eutrophication? Causes? Impacts? Potential solutions?
Eutrophication: "Perhaps greatest threat to coastal ecosystem today." (NRC, 1993) Ecosystem response to nutrient addition: - Increased algal productivity - Microbial decay of dead organic matter consumes oxygen Anoxia in water column - Some cases of extreme 'green tide' Nutrients from Point (wastewater from municipal and industrial facilities) and Nonpoint (diffuse: ag. runoff, atmosphere etc. ) sources. Nutrients washing down the Mississippi from farm and towns cause algal blooms in Gulf of Mexico creating a 'dead zone' Solutions to the Eutrophication Problem -restore wetlands and river-side buffer zones -reduce livestock densities -improve efficiencies of fertilizer applications -treat urban runoff from streets and storm drains -reduce N emissions from vehicles and power plants -increase efficiency of N and P removal from municipal wastewater
What is the scientific evidence for global warming?
Evidence: The short-term (instrumental) record: - All global temp. reconstructions show warming since 1880 - Most of this warming has occurred since the 1970s - Increase of: 0.8 oC = 2 oF - All 10 of the warmest years occurring in the recent past (since 1998). - Ocean warmth also increasing: ARGO temperature profiling 0-700 m layer Evidence: The long-term record: - Multi-proxy record from ice cores, tree rings, sub-fossil pollen, corals, and lake, ocean sediments, etc. shows unusual warming Evidence: Changes in ice coverage Increasing ice loss and rates of ice loss in all portions of the cryosphere. Very few observtions of ice gain. -Glaciers are retreating almost everywhere around the world (including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa) - Both the extent and thickness of Arctic sea ice has decreased over the last few decades. - Shrinking polar ice sheets - The rate of ice loss from Greenland has increased almost five-fold since the mid-1990s Evidence: Increased extreme meteorological events - Climate change cannot, with certainly, be linked to any single weather event ...only extreme weather trends. - very likely that the number of cold days and nights has ↓ - very likely the number of warm days and nights ↑ - likely that heat wave frequency has ↑ - likely that number of heavy precipitation events over land has ↑ in more regions than it has decreased Evidence: Atmospheric temperature profile - Satellites measure less heat escaping out to space, in the IR wavelengths that CO2 absorbs
What is the general story of the evolution of fishes? And tetrapods from fishes?
Evolution hypothesis: vertebrates evolved in estuaries New fossil species found in 375 myo artic rocks Intermediate stage between fish and tetrapod Has neck, jointed fins and scales like a fish Why? Possibilities: Climate change Food source Escape predation
What was the first animal?
First animals were marine Genetic evidence suggests ctenophores are more ancient than sponges (comb jelly)
What are the different classes of fishes and general characteristic of each?
Fish Classes Agnatha (Jawless Fish) lampreys, hagfish (most 'primitive' fish) Chondrichthyes (Cartilaginous) (sharks and rays) Osteichthyes (Bony fish) mostly of Order: Teleost Chondrichthyes (Cartilaginous fish) Sharks and rays Less articulated, less maneuverable Slow, gliding motion No swim bladder Most sharks bear live young (viviparous) Bony fish: Teleosts There are about 25,000 described species of fishes living today, more than all other vertebrate groups combined -Highly articulated skeleton -Flexible, easy to maneuver -Fast, sprinting motion
tragedy of the commons
Free access and unrestricted demand for a finite resource ultimately reduces the resource through over-exploitation, temporarily or permanently
Nekton
Free swimmers pelagic realm
What is the spring bloom and why, where, when does it occur?
-most production is in the Spring at higher latitudes (lots of nutrients, suddenly more light..SPRING BLOOM)
Why will the effects of sea level rise be more extreme for Florida than for most other places?
Greatest size of at risk population (75% live in a coastal county) Large area of low elevation (8,426 miles of tidal shoreline) high incidence of hurricanes - high $$ value of coastal buildings & infrastructure - reliance on coastal tourism - limestone bedrock: 1. porous aquifer allow saltwater intrusion, 2. Conventional seawalls not effective)
What is the greenhouse effect? What do greenhouse gases do to cause warming?
Greenhouse gases absorb and re-emits energy emitted by the earth's surface (long wave infared radiation) -Greenhouse Effect is 'mostly natural' - Atmosphere CO2 increase recorded at Mauna Loa Observatory - Atmosphere CO2 increase recorded in air bubbles trapped in ice cores
Benthic Zone
Habitats on the seafloor Epifaunal (living on the sea floor) Infaunal (within.or.buried in sediment on sea floor)
What type of vents versus hot and cold seep environments?
Hot: Hydrothermal Vent Cold: Brine seep (Florida) Cold: hydrocarbon seeps (Gulf of Mex.) Cold: Subduction zone seeps Hydrothermal Vent Community Issues - temporary nature, fragile? -larvae of deep-sea hydrothermal vent species must travel unprecedented distances Brine Seeps - Recently discovered on the Florida Escarpment at 3200 m
What are the major types of marine pollution and which are of greatest concern?
INTENTIONAL DUMPING Solid Waste Sewage Industrial waste (dissolved and solid waste) Heat: nuclear plants ACCIDENTAL DUMPING Invasive Species Petroleum Eutrophication (nutrient pollution causes over-production of algae) SOLID WASTE London Convention, 1972 - prohibits marine dumping of hazardous materials (all industrial and radioactive waste) - allows dumping of sewage & many other wastes. U.S. Law now bans dumping of all sewage and plastics. Stilll, millions of tons of solid waste dumped each year Plastic are one of the biggest problems: Slow to degrade (6-pack ring takes 400 yrs to decay). U.S. produces 1000 lbs plastic trash/person/yr Great Pacific Garbage Patch: An area of trash that is twice the size of Texas. 80 %t plastic (3.5 million tons). trapped in geostrophic eddy currents. growing tenfold every decade Massive North Atlantic Garbage Patch now mapped DISSOLVED WASTE Organic chemicals (pesticides, cleaning fluids etc.) DDT PCB's PAH's TBT (tributyl tin): added to boat paints to kill or repel barnacles and other nuisance organisms that foul ships' hulls. Heavy Metals (don't degrade) Mercury (coal burning, industrial use), Copper, Lead... Contaminates seafood, causes birth defects and nervous system damage Bioaccumulation Increasing concentration up food chain Petroleum Most enters oceans from 'normal' shipping operations and from land industrial (not refinery) and municipal sources.
How do we determine sea level in the distant and recent past?
Ice volume calculation using ratios of stable isotopes of O and H in ice and sediment cores - location of ancient coral reefs - human (historical) records - buried datable surfaces Modeling
Why is being a vegetarian environmentally beneficial?
If you are a vegetarian, "eating lower on the food chain", you've only lost 90% of the sun's energy If you eat meat, you're losing 99-99.99% of sun's energy + energy loss from processing & transport But eating lower on the food chain or just eating less meat will lessen environmental degradation
What are some forces standing in the way of effective fisheries management?
Lack of understanding Problems with MSY: Hard the figure out exactly what the threshold is for each species, Monitoring total population size is difficult, Doesn't consider: -Species-specific variations in size age repro status - Associated damage to ecosystem - Fact that fish populations naturally fluctuate -Focus on one species when there's a complex food web Failure to heed scientific advice -Pirate fishers that don't respect laws or agreements -Lack of political will -Government subsidies can help or hurt but most lead to overfishing
Marine Adaptations for Darkness
Large Eyes/light sensitivity Large eyes let in more light Bioluminescence (also Iridescence) Found commonly in deep sea organisms Produced by symbiotic bacteria kept in cells self-luminous cells: photophores Counter-illumination Echolocation Mostly marine mammals: dolphins, whales interpret echo returns and in terms of distance, size, texture and swimming direction of prey Make a rapid clicking noise with an specialized organ (not vocal cords) Sound received in lower jaw and transmitted to inner ear May use sound to stun or kill prey Volume: dolphins - 230 decibels, sperm whales - 260 d, military jets- 130 d Electrosensing - Ability of some fish to detect other organisms by sensing the weak electric field that surrounds them OR detecting disturbance in electric field emitted by the fish
What do phytoplankton need? What adaptations do they have to get it?
Light: needs to stay up in the photic zone...special adaptations Nutrients: Finds it near coasts, upwelling zones (aeolian dust) ...special adaptations A carbon source: Uses CO2 plenty dissolved in water from atmosphere ADAPTATIONS Buoyancy - most contain a small drop of oil (less dense than water) Frictional Resistance - high surface area to volume ratio by being small...being ornate (in warm less dense water) Turbulence within the upper mixed later - top 200 m - above the thermocline Zooplanton - have some ability to 'swim' and migrate up and down in waster column
marine protected areas
MPA protections include limits on development, fishing gear types, fishing seasons, catch limits, moorings, to complete bans on removing marine life of any kind (0.8% of ocean). -The U.S. has more than 1600 MPAs (cover 36% of U.S. marine waters) -But vary widely in purpose, legal authorities, managing agencies and approaches, level of protection, and restrictions on human uses.
What are some of the possible solutions to overfishing? What are some methods of marine management?
1) Reduce Fishing Effort 2) Better Science/Better Policy 3) Close some areas to fishing (Protected Areas) 4) Aquaculture
What processes control local (relative) sea level?
1. Global sea level 2. Vertical movement of land surface Subsidence due to: - plate tectonics - ice or sediment loading - oil or water extraction Uplift due to: - plate tectonics - post glacial rebound - enhanced buoyancy(?) (e.g. Florida platform dissolution) 3. Local ocean surface (currents, winds, atm. pressure)
What effects are sea level rise predicted to have on coastal landforms and populations?
1. Inundation - Water covering normally dry land Longer-Term Coastal Inundation: global sea level rise, relative sea level rise (land subsidence) Episodic Coastal Inundation Events: storm surge, tsunamis, inland flooding, and shallow coastal flooding Destabilization of the West Antarctic ice sheet could lead to 5 meter increase (17 ft total) If all the ice melted sea level would rise 216 feet 2. Actual loss due to sea level rise depends upon: - composition/stability of shoreline, sediment supply, shore slope and geometry, vegetation, storm patterns, humans SL rise of 30 cm (about 1 ft) would cause retreat of: - 50-100 feet in New Jersey - 200-400 feet in California -100-1000 feet in east Florida (30-300 m) 3. Damage to natural resources/ecosystem Tidal wetlands (bogs, salt marshes, swamps, sea grass, mangrove) are important: - high biological productivity and biodiversity - sequester large amounts of carbon - provide habitat, nesting, feeding for juvenile forms of many of organisms such as shorebirds and fish - improve water quality by trapping contaminants - buffer storm impacts and erosion, stabilizes shorelines - provide recreation opportunities 4. Magnifies the impacts of storms: higher storm surge, greater flooded area, - deeper waters near shore results in faster flow, higher waves and impacts on shorelines and coastal structures - impairs storm water drainage systems 5. Saltwater intrusion SL rise accelerate movement of saltwater into freshwater surface and groundwater sources near the coast - occurs much further inland than land loss - drinking and irrigation water wells must be abandoned. 6. Damage to man-made coastal infrastructure coastal industries and infrastructure (transport, power, water supply, sewerage) are highly sensitive SL rise. - rarely built to accommodate SL rise - asset exposure estimated at 9% of global GDP in 2070 7. Danger to human health expansion of brackish and saline water bodies in coastal areas may increase the incidence of vector-borne diseases, diarrhea and hypertension - degradation fisheries and aquaculture which contribute significantly to the dietary protein of millions of people and world trade
What processes control global sea level?
1. Volume of water in the ocean - Varies due to changes in: - Land-based ice volume (not sea ice) - Changes in terrestrial water storage - Ocean Temperature (thermal expansion) 2. Volume of the ocean basins -Varies due to long-term changes in: - Continent arrangement (plate tectonics) - Rates of seafloor spreading (plate tectonics)
What is the 10% rule?
10% Rule: Only ~10% of energy flows up the pyramid 90% of energy is lost at each level: used for metabolism (heating, eating, breathing, reproducing, moving...) and inefficiency (e.g. excretion)
What amount of sea level rise is predicted by 2050 and 2100?
22cm by 2050 and 50-100cm by 2100
What proportion of scientists versus the public believe global warming is happening?
95% of scientists; about 50% of public?
What are the characteristics and activities of marine bacteria?
Marine Bacteria: ABUNDANT and DIVERSE Blue-green algae (cyanobacteria) Responsible for ~25% - 50% of marine primary production ~20% of marine biomass Picoplankton (0.2 and 2 μm = 1/1000 mm)
Marine Adaptations to Stay Afloat
Microplankton (Phyto and Zooplankton) - need to stay in sunlight: many contain a small drop of oil (less dense than water) to be buoyant use the viscosity of water: keep high surface area to volume ratio by being small and ornate (more so in less dense warmer water) Don't want to use energy swimming vertically - maintain neutral density Many cephalopods (squid, nautoloids) have gas filled chambers Giant Squid muscles contain weak ammonia (buoyant) solution Some fish (weaker swimmers) have swim bladders (balloon-like organs) can be filled or emptied by transfer of gas to and from blood or gulped from surface Can implode or explode with rapid depth change, so many predators have fat filled bladders
Why are benthic organisms so diverse?
More than 98% of known marine species are benthic (biodiversity because of evolution to match diversity of environments and lifestyles) Many potential niches (specialization) Complex structure Stablity?
Marine Adaptations to Salinity
Most open ocean and deep-water organisms can withstand only a small salinity change (stenohaline) Many shallow-water coastal organisms can withstand changes in salinity (euryhaline) Diadromous Fish - migrate between FW and SW Problem is diffusion of ocean salts into body & osmosis of water out of body Tendency toward making distributions all equal..... Adaptations to cope with: Salinity: SOLUTIONS - Be Isotonic: Keep bodily fluid the same salinity of seawater e.g. most marine invertebrates Be Hypotonic: less salty than water drink a lot of water, secrete salt from special cells small volume of concentrated urine Be Hypertonic: saltier than water Do not drink water Keep salts absorbed in special cells large volume of dilute urine
What types of organisms are responsible for the primary production of the ocean?
Mostly phytoplankton (>90%) i.e. algae (Microscopic, single cell floating organisms) Also some Macrophytes: A few plants e.g. sea grasses, mangrove Macroalgae: Protists: seaweed, Coral (algae/animal symbionts)
What is natural selection?
Natural selection (adaptation that fill niches) the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.
Meroplankton
Organisms that spend only part of their life cycle in water column
What types of organisms (phyla, lifestyles) make up the benthos?
PHYLAS: Porifera (Sponges) Cnidaria (Jellyfish, Corals, Hydroids) (old name: Coelenterate) Ctenophora (Comb Jellies) Mollusca (Clams, Snails, Octopi) Arthropoda (Crabs, Shrimp, Lobsters) Echinodermata (Sea Stars, Brittle stars) LIFE STYLES Infauna: Plants, animals and bacteria of any size that live in the sediment (micro, meso, macro) Epifauna: attached to the hard bottom or substrate (to rocks, reefs, debris) live on the sediment surface Demersal: Bottom-feeding or bottom-dwelling fish that feed on the benthic infauna and epifauna
Pelagic zone
Pelagic Zone: Habitats within the water column photic, aphotic and abyssal
What types of organisms make up the zooplankton? (Know example zooplankton Ctenophore, Chordates, Cnidarians, Arthropod, Mollusks)
Phylum Chordate - Salps (planktonic tunicates) Arthropods "joint foot" Class: Meristoma - horeshoe crabs Class: Crusacea - shrimp, crabs, etc. exoskeleton,3 body segments, jointed legs and appendages large & diverse group with many zooplankton and benthos crabs, shrimps, krill, water fleas, barnacles etc. Copepods: probably found in every fresh or saltwater body. Possibly the most abundant animal on Earth EX: Krill (euphausiids) are small, shrimp-like crustaceans dense masses called "swarms" or "clouds," that turn polar ocean's surface pink Phylum: Cnidaria (Coelenterates) Two basic body types (most have both during life cycle): Medusae - free floating stage (jellyfish-like..above) Polyp - attached to bottom (adult corals and anemones) Have stinging cells (nematocysts), carnivorous Phylum:Ctenophores(Comb Jellies) Carnivorous Beat cilia to 'swim' No stingers, captures prey on sticky cells Meroplankton - zooplankton larvae and juveniles of a range of organisms
What types of organisms make up nekton?
Phylum: MOLLUSCA invertabrate Class Cephalopoda " head foot" -surrounded by tentacles Swimming by propulsion - squirt water from an interior cavity Carnivores - Catch prey with suction cup feet, kill with "beak" squid has: Two fins , A mantle , A head , 8 arms and two tentacles, each with hooks and/or suckers octopus has: mantle , head , 8 arms with one or two rows of suckers no tentacles Phylum: CHORDATA (have a notocord: cartilaginous rod running underneath nerve cord) -Invertebrates e.g. tunicates (sea squirts) -Vertebrates (have spinal column)
What are the defining characteristics and major groups of marine mammals discussed in class?
Phylum: chordate Class: mammalia Orders SIRENIA : Manatees, sea cows, dugong The only herbivorous marine mammal Slow moving, small brained Subtropical Closest marine relative to elephant Near extinction (~10,000 individuals, Florida count 2001 = 3,276) Loss of habitat, boats, red tide CARNIVORA: Polar bear Seals sea lions walrus sea otter Pinnepeds: wing foot, evolved from bear group Seals (no ear flaps) Sea lions (with ear flaps) Sea otters: smallest marine mammal Most leave water to mate and raise young Elephant seal - deep diving record - 1.5 km Threatened, covered by 1972 Marine Mammals Protection Act CETACEAN (Whales) Descended from ungulates (cows, camels, hippos) Arms became paddle-shaped fins used for steering, legs are vestigial bones
What are some characteristics and obstacles of life in the deep sea?
Pitch Black, Nearly Freezing, High Pressure Far from food source 90% are bioluminescent Nutrients from whalefalls
Marine Adaptations to Hydrostatic Pressure
Problem for animals that migrate through the water column for food SOLUTION: Don't have rigid air pockets Have water-filled pockets so pressure inside = pressure outside Diving marine mammals have no sinuses and compressible rib cage and lungs Another Problem: The 'bends' = nitrogen narcosis During quick ascent, the N2 becomes less soluble and forms bubbles in blood N2 bubbles can obstruct capillaries Solution: Collapse lungs so no air exchange while diving
What are some problems and solutions with use of maximum sustainable yield as a tool for marine resource management?
Problem with MSY Concept : Lack of Information -Monitoring total population size costly and imperfect Doesn't factor in: -species-specific variations in size, age, repro. status -associated damage to the ecosystem - the fact that fish populations naturally fluctuate - focused only on single species...complex food web interactions
What possible adaptation strategies to we have to respond to sea level rise?
Protection: defensive measures to mitigate (lessen) the impacts of rising seas: 'hard' methods and 'soft' methods: (natural protection) Accommodation: alter design so structures or infrastructure resist damage or operate more efficiently in new SL regime - Retrofit or alter design of structures or infrastructure by: - raise structures (houses, bridges, etc.) - improve storm water drainage - increase setbacks from watercourses - reduce liability Retreat (managed retreat): -removal of existing development & possible relocation - avoid or discourage new building in hazard areas - build only non-permanent, movable, elevated, floating may involve land acquisition, transfer of development rights, conservation easements
What is a food chain/web?
Pyramid implies a linear food chain In reality- communities best described as food webs Most organisms have a choice of more than one food source Complex feeding interactions
What are the different habitat zones and which benthic organisms live there?
ROCKY SHORE VERTICLE ZONATION Spray and high tide zone - Animals close up during low tide and can survive drought Middle tide zone - Can survive short exposures to air (~6 to 12 hours) by closing (barnacles and mussels), having tough outer skins (chitons and anemones), or hiding in damp places (hermit crabs, worms). Low and sub-tidal zone - Brief or no exposure to air: bivalves, anemones, starfish, sea squirts, crabs, sea cucumbers, sea slugs, sea squirts. Must tolerate high energy Benthic algae - seaweed: colonial protists, some plants). No roots (some with holdfasts) SANDY SHORES Beaches, Salt marshes, Mud flats (mainly Infaunal) less vertically differentiated inhabitants can burrow during low tide worms, crabs, starfish, sea cucumbers, bivalves, and crabs and smaller arthropods due to erosion, all must be capable of finding new dwellings Epifaunal/Infaunal -Rocky Shores/Sandy Shores (vertical zonation) Spray zone (rarely covered by water) High tide zone Middle tide zone Low tide zone (rarely exposed) -Coral, Mangrove -Shelves/slopes/rise -Deep Sea (abyssal plains) -Hydrothermal Vents
What types of non-coral reefs are there?
Reef: a rock, sandbar, shipwreck lying just below beneath water surface
What is causing the present high rate of sea level rise?
Alpine glacier loss (15%): contributes 0.6 mm/yr to sea level rise . Most glaciers world-wide are in retreat Ice sheet loss (25%), contributes 1 mm/yr to sea level rise . Greenland and Antarctic Ice Sheets are melting at accelerating rates Thermal Expansion (52-65%): water density decreases with heating global 20th century warming ~0.6 C would produce 1.6 mm/yr sea-level rise
What is the general history of sea level in the past 20 thousand years?
Sea level was highest during the Mesozoic Era (60 m.y.) and has dropped since...but not continuously.
Compare and contrast marine versus land species diversity and biomass
Seas contain only 1% of living biomass half (40-50%) of earth's primary production (mostly photosynthetic) occurs in sea 17% of all species in the ocean Land has more species diversity bc: Less pressure to evolve bc its more stable and less complex Fewer barriers to gene flow in ocean
Target Catch
The species of fish or catch that is primarily sought in a fishery (ex. tuna, shrimp, flounders)
Which types of species are most vulnerable to overfishing?
Those with long lifespans (longest regeneration time)(top predators) Those that rely on a specific habitat or food source Those with a small range (occurs when numbers are reduced)
What are the differences between toothed and baleen whales and major members of each?
Toothed Whales: sperm whales, belugas, narwhales,killer whales,dolphins, porpoises Single blowhole = nostril Teeth Active Predators, Intelligent? Social, communication Echolocation brain/body ratio (~0.016) matches that of archaic humans of ~2 mya Baleen Whales includes: grays, humpbacks, blues Filter feeders No echolocation Baleen in place of teeth= fringed material, from roof of mouth, sieve to trap zooplankton Whales Nearing extinction ~ 1 million total (4.4 million in 1900) Hunted by man for Food, oil, baleen for corsets, perfume Now have a substitute for all uses
What is a trophic pyramid?
Trophic Level = the position that an organism occupies in a food chain Trophic Structure = How an ecosystem uses and transfers energy -Can be represented by a Trophic pyramid -Shape represents Biomass or Energy contained at each level (smaller upward) -Base of the pyramid are primary producers (make their own food) mostly photosynthesize -Upper levels feed from the level below
What are the different environments of a reef?
Types of Coral reefs: (all grow upward when land subsides)- Fringing (no lagoon), Platform, Barrier, Atoll Hard Coral: Reef-building, secrete CaCO3 , multiples of 6 tentacles, symbiosis with zooxanth. (stony corals, or scleractinians) Soft Coral: Non-reef-building, little CaCO3, 8 tentacles, feathery, often toxic, spiky spicules (gorgonians or octocorals) Sponges, bivalves, worms (tube worms), prokaryotes (stromatolite) may also be reef-builders
What can you do to help reduce overfishing?
VOTE and contact your representatives Eat less seafood (be vegetarian) Eat low on the food chain Eat only sustainably-caught/managed seafood
How is genetic variation produced in a population?
Variations from: -mutation (random changes in gene pool) -gene flow (an individual of one moves to another group) -genetic drift (when groups of individuals get separated) (need barriers to gene flow) -lateral gene transfer (cross-species genetic transfer)
Where and when would you be likely to find high or low levels of marine primary productivity? Why?
WHERE High productivity regions: -Coastal zones -Upwelling regions (equatorial and Southern Ocean, the North Atlantic) Low productivity areas: -Center of gyres (downwelling) -High latitude winters (low light) WHEN When there is enough sunlight: spring - summer - fall (because of greater day length and angle, but mostly because of shallow thermocline then) When there is enough nutrients: winter - spring (because winds mix water column, but mostly because of weaker thermocline then)
Why are many whales endangered?
Whales Nearing extinction ~ 1 million total (4.4 million in 1900) Hunted by man for Food, oil, baleen for corsets, perfume Now have a substitute for all uses
Effort
a product of the total number and size of boats and the number of days they fished
Benthos
benthic realm Bottom dwellers Attached to bottom or free moving
Incidental Catch
catch of non-targeted species that is kept
CPUE
catch per unit effort indirectly measures abundance of fish population Threshold Catch = # that can be caught without a decrease in the population size
What is the base of the food chain in the deep sea normally and at vents and seeps?
chemosythesis-based communities: have autotrophy at food chain base: hydrogen sulfide or methane oxidizing bacteria as primary producers...shows that life can exist independently of the sun. All vent communities have hydrogen sulfide or methane oxidizing bacteria as primary producers (base of the food chain)
Abyssal zone
deep, deep ocean
Aphotic zone
deeper than light can penetrate
Heterotroph
eat other organisms
Bycatch mitigation
efforts to make bycatch less severe
Autotroph
make their own food (mostly photosynthesis)
maximum sustainable yield
maximum amount of any resource that can be harvested without affecting future yields occurs at about 30% of unexploited population size in most fisheries models
maximum economic yield
maximum economic yield: maximum difference between revenue and total cost
Plankton
pelagic realm, phytoplankton, zooplankton Floaters and drifters
Discarded Catch
portion of the catch returned to the sea (economic, legal, or personal considerations).
fishing down the food chain
targeting increasingly large quantities of smaller fish that play a critical role in the marine foodweb
Commercial extinctions
the depletion of a species to the point where it is not profitable to harvest exceeding the carrying capacity of a fishery
Photic Zone
upper 100 m that receives sunlight
Photosynthesis
use of sunlight to create food for autotrophs with carbon dioxide and water
