Marine biology exam #1
What are the components of an animal's energy budget (i.e. inputs and outputs)?
consumption (food) metabolism (respiration (consumption of O2)) + production (reproduction and growth) + waste
How can organisms respond to changes in their environment?
- Organisms respond to information collected from the environment • Responses can vary and all require energy • Organisms can acclimateto a changed environment
How is a boundary layer related to Re?
- Re < 1 "world of viscosity" (moving is hard, small slow organisms) (boundary layer very important)
What conditions lead to turbulent flow?
- Re < 2300 = laminar flow (low Re) - Re >2300= turbulent flow (high reynolds number) - faster water - irregular surfaces (increasing size, rocks) - high density - low viscosity
What affects can Bernoulli's principle have on marine organisms?
- Sessile and moving organisms experience drag - Hydrodynamic adaptations involve tradeoffs Drag on a fish is affected greatly by streamlining (Levinton)
What are density and viscosity?
density (pho)=mass/volume=g/mL=g/cm2 viscosity (ri, mu)= molecular "stickiness"
How are density and viscosity affected by variation in temperature and salinity?
density goes up as temp. goes down density goes up as salinity goes up viscosity goes up as temp. goes down
What happens to an organism if food availability exceeds metabolic demands (maintenance metabolism)?
growth and reproduction
How does ENSO and other climate oscillations affect ecosystems, broadly speaking? I.e. through what mechanisms do climate oscillations impact living organisms?
- Upwelling off the coast of Peru supports a productive fishery - Periodically reverses when the wind changes direction, leading to catastrophic declines in fish catches - impacts weather worldwide, and impacts marine (and terrestrial) ecosystems
What are some likely functions of bioluminescence?
- attract prey/predator (for predators predator) - confuse predators - warning - attract mate - camoflaug
Why are fish particularly sensitive to increases in salinity?
- bony fish are salinity regulators (maintain constant body salinity) - marine fish/ freshwater fish who are regulators
How do changes in salinity impact organisms?
- can affect osmosis (might gain or lose water) and diffusion (might gain or lose solutes)
What adaptations do animals possess to deal with temperature changes?
- counter current heat exchange - convective heat loss - contour feathers - down feathers
How is climate warming likely to impact oceans?
- green house effect (warms the earth surface) - increase in carbon dioxide in the atmosphere - warms sea surface temp. - rise in sea level which changes oceanic circulation - ocean acidification - calcium carbonate skeleton will be affected (coral, mollusks, plankton)
How can an organism's performance be measured in response to environmental change?
- growth - reproduction - mortality
How does turbulence impact organisms?
- makes moving easier
What environmental challenges do intertidal organisms experience?
- may be exposed to air when tide goes down
From where do marine sediment in the deep-sea originate?
- mineralized plankton skeletons - clay - volcanic rocks - precipitates (manganese nodules)
How is salinity measured?
- most common/reliable: conductivity (use practical salinity units (PSU)) - Evaporation - Chlorinity titration (hard) - Optical refractometer (only accurate to about 2 part per thousand) - Satellites (surface salinity using the radiometer (error prone))
What two processes control surface currents?
- planetary wind systems - earths rotation
What are defining characteristics of estuaries?
- semi closed body of water - free connection with the open sea - seawater diluted by freshwater from land drainage
What mechanisms do organisms have to counteract changes in salinity?
- some maintain osmotic gradients (by having sugars, amino acids, or urea (sharks))
What techniques are used to map the ocean floor?
. Bathymetry - depth ("bathy-") measurement ("-metry") 2. Isobaths - same ("iso-") depth. Contour lines in the oceans (and inland waters) 3. Depth sounding - measuring depth (from Old English sund water, sea) Usually in m or fathoms (2 yards = 6 feet)
What are the two major affects of boundary layers on aquatic systems and organisms?
1) objects slow down as they approach the bottom 2) concentrate or depletion of substances in the boundary layer - concentration of waste (ammonia) - depletion of nutrients
What is the typical salinity of the open ocean?
33-37 PSU (35%)
What is anoxia, and why might it occur?
Anoxic conditions: water depleted in dissolve O2, bad for living organisms (hypoxia can cause algal blooms) - being in the thermocline layer - bacterial decomposition of the organic matter and consumption of oxygen (results in an absence of oxygen (oxygen minimum layer))
Which element is/are most variable?
Carbon, oxygen, nitrogen, phosphorus, sulfur - Vary because they are very biologically active/used
What are practical salinity units?
Compare conductivity compared to passing Chloride standards (KCl) PSU=ppt
What is a CTD, and what are the principle types of measurements made by a CTD?
Conductivity (salinity) - temperature - depth (using pressure) platform (CDT) Measurements: - Salinity - Temperature - Depth - DO - Chlorophyll (by fluorescence) Water sampling (Niksin bottle "tubes" in a circle called a "rosette) - Phytoplankton - SPOM - chemicals
How do continental and oceanic islands differ geologically?
Continental: are part of an adjacent continent and are located on the continental shelf of that continent. - Ex. Greenland oceanic islands: not geologically connected to a continent built usually by volcanoes (oceanic rift or hotspot)
How does salinity vary latitudinally, and what causes this pattern?
Decrease salinity (higher latitudes and equator): - Melting - Rain fall (precipitation) - River/ground water inputs (runoff) Increase in salinity (max 30 degrees N and S): - Evaporation - Ice formation Baltic sea - Low salinity - Spring runoff - Marginal seas most variable Mediterranean - High salinity - Dry summer (evaporation)
What is thermohaline circulation?
Density differences due to temperature and salinity variation lead to deep-water
What processes drive the concentration of dissolved oxygen in the oceans?
Driven by photosynthesis, respiration (CO2+ H2O+ light=> C6H12O6+O2), chemical and physical processes
What is ENSO?
El Niño-Southern Oscillation: - worldwide climatic oscillation in the ocean-atmosphere system
What were the first real hypotheses in marine biology, developed by Forbes and Darwin?Can you describe one of them? Why are they considered true hypotheses?
Forbes: - azoic theory: that no life existed on sea floors deeper than 300 fathoms Darwin: - development of coral: coral reefs growth is a balance between the growth of corals upward and the sinking of the ocean floor true hypotheses because they are testable statements about the world of the sea
What is maintenance metabolism and how is it estimated? How might it vary with environment?
Maintenance metabolism estimated by respiration •Maintenance metabolism and food availability vary => scope for growth
Which elements fall in each group? (major, minor, and trace elements)
Major elements (> 100 ppm): - Chloride (Cl), Sodium (Na), magnesium (Mg), sulfur (S), Calcium (Ca), and potassium (K) Minor elements (1 - 100 ppm): - Beryllium (Br), Carbon (C), Strontium (Sr), B, F Trace elements (< 1 ppm): - Nitrogen (N), Phosporus (P important in DNA), Iron (Fe important for primary producers)
How are major, minor, and trace elements defined?
Major: those present in concentrations greater than 100 ppm minor: concentration between 1-100ppm trace: concentration less than 1 ppm
What elements are fairly constant in proportion?
Na, Cl, Sr (Strontium)
how does the Coriolis affect weather and current patterns in the northern and southern hemispheres?
Northern hemisphere: rightward, clockwise southern hemisphere: leftward, counter clockwise
How do marginal seas generally differ in physical conditions from the open oceans?
Open oceans: - typically more constant temperature - relatively consistent salinity - deeper water marginal seas: - variable temperatures - variable salinity - shallower water depth - high impact of local climate
What other processes effect salinity, and which areas are consequently more variable?
Other materials in seawater: - Organic aggregates ("marine snow") - Inorganic particles - Living plankton - Dissolved gases
What are the five oceans?
Pacific Ocean Atlantic Ocean Indian Ocean Southern Ocean aka Antarctic Ocean Arctic Ocean
What are some defining characteristics of each ocean?
Pacific Ocean: largest ocean Atlantic Ocean Indian Ocean Southern Ocean aka Antarctic Ocean Arctic Ocean: smallest ocean
What geologic process is responsible for the earth's large scale features, including much topography of the oceans?
Plate tectonics: - Continental shelf - Continental slope and the shelf-slop break - Deep-sea floor or the abyssal plains - Oceanic ridge system Trenches: continental slopes cause these Continental and oceanic islands/ oceanic ridges: continental shelf
Why is it important to consider and which organisms are most likely to be affected by the Re "grey area"?
Re 1-1000= "grey area" velocity and size mater not just density and viscosity
What is the Re "gray area"?
Re 1-1000= "grey area": where density and viscosity matters
Assuming density and viscosity are relatively constant, what can we assume about Re for small, slow objects as compared to large, fast objects?
Re for small objects: "world of viscosity" - moving is hard, small slow organisms - must constantly work to survive Re for large objects: "world of inertia" - hard to stop, large fast organisms - can coast
What is equation for Reynold's number (Re)?
Re= inertia/viscosity Re= (velocity*size*density)/viscosity
What is salinity?
Salinity: Total dissolved inorganic solids in water (g/kg, or ppt)
How do temperature and salinity impact [O2]?
Temperature and salinity - Higher DO in cold water and less salty water - Lower DO in hot water (evaporation) and salty water
What is scope for growth?
The surplus of energy available for growth beyond that required for maintenance
what does thermohaline circulation depend on?
These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). produced by the production of briny, cold water produced at the surface in polar regions
Where is SST most variable? Least variable?
Tropics and poles: relatively constant (open ocean most constant) Temperate (mid latitudes), coastal areas, and marginal seas: most variable
What causes the Coriolis Effect?
anything traveling long distances appears to be deflected
How does O2 consumption change with body mass?
as body mass goes up O2 consumption goes down
What is a boundary layer?
as fluid approaches a surface fluid velocity decreases to 0
As a medium for life, what benefits and challenges does water present?
benefits: - not so hard on the body - easier to float challenges: - harder to move
Why is upwelling biologically important? (There are many answers to this question)
brings nutrients to surface, grows algae, feeds animals.
What are homeotherms and poikilotherms?
homeotherms (regulators): regulate body temperature to a constant level (usually above ambient environment) - ex: birds poikilotherms (conformers): body temperature conforms to that of the ambient environment - ex: marine invertebrates and most fish
How does environmental temperature affect homeotherms and poikilotherms differently?
homeotherms: as temp. goes down metabolic rate goes up poikilotherm: as temp. goes up so does metabolic rate
What happens is metabolic demands exceed energy available from food?
might die (definitely not grow)
What are gyres?
movement of tremendous volumes of surface water in large circular patterns
To what approximate depth is sunlight sufficient for photosynthesis?
photic zone depth (photosynthesis occurs) - 50-100 m - <10m in turbid waters - deeper in clear nutrient poor waters
What range of temperatures are common for SST?
polar water: 0 degrees Celsius tropical water: 25-35 degrees celsius
How do some organisms reduce or increase drag, and why?
reduce: - sea weed bend so they can be parallel with the current - flexability - skin types why: - to be faster increase: - larger surface area - larger size may equal more food - larger size to not be preyed on
What does it mean to describe an organism as a regulator or a conformer?
regulator: maintains constant physiological conditions in the face of environmental changes conformer: changes physiological conditions to match environment
What information does Re give us about the conditions an organism experiences?
relative importance(affect) of inertia and viscosity
How do salinity, temperature, dissolved O2, and light vary with depth?
salinity: as depth increases so does salinity temperature: as depth increases temp. decreases dissolved O2: high at top hits oxygen minimum then increases slightly with depth light: decreases as depth increases
How is sea surface temperature measured?
satellite radiometers
What are semidiurnal, diurnal, and mixed tides? What factor lead to these different tidal patterns?
semidiurnal tides: 2 high and 2 low tides a day diurnal tides: 1 high and 1 low tide a day mixed tides: varies from day to day causes: - basin shape - orbits of moon and earth - tilt - surges of water - water movement
How do different animals acquire oxygen for respiration, and deal with low O2 conditions?
small organisms: diffusion large organisms: need gills dealing with low O2 conditions: - anaerobic pathways - process oxygen-binding pigments (ex. hemoglobin) for storage and regulation of O2 (used for diving deep)
What are and when do spring and neap tides occur?
spring tides: big/strong tides, every new or full moon neap tides: smaller tides, quarter moon
What is Bernoulli's principle?
states that pressure varies inversely with fluid velocity (the pressure difference creates lift) (oceanic worm uses it to bring nutrients through hole)
What expedition during the late 1800s began the modern era of oceanography? What famous ocean feature was discovered and named after this expedition? What else did this expedition accomplish?
the Challenger led by C. Wyville Thomson and john murray
What is upwelling?
the upward movement of deeper waters near the coast
How do the sun and the moon contribute to tides?
they cause tides with their gravitational attraction - moon is closer so more influence (high tides when moon is above or across from water)
How does drag affect marine organisms?
well streamlined: - wake reduced - streamline maintained behind the fish - drag is reduced poorly streamlined: - wake is created - produces a pressure gradient and drag
How is turbulent flow different from laminar flow?
turbulent flow: - irregular flow (water molecules all over the place) - rough waters (rapids) laminar flow: - regular flow (water molecules going in a parallel flow)
What types of light are strongly attenuated by sea water?
ultraviolet and infrared
how do tube-dwelling (or burrow-dwelling) organisms take advantage of the Bernoulli principle?
using a u shaped tube in the mud with one entrance to the tube opening to a small rise, higher than the adjacent entrances - higher entrance = higher current velocity which acts as a flush bring nutrients to the organism
Which wavelengths of light penetrate deepest?
visible parts of the spectrum (blues and some greens)
How do marine organisms detect light and how is vision important?
ways light is detected: - photoreceptors (sensory cells) - pinhole eye/camera - eyes with lenses - eye with concave mirrors importances: - mating - shows venomous (bright colors = poisons) - attracts food - cues for migration
Can an organism be both a conformer and a regulator at the same time?
yes