oceanography
Pro-karyote
Simple cell no membrane bound organelle. Ex. bacteria
True or false: Light penetrates deeper into the open ocean than into surface waters
True
True or false: there are more small species than large species
True
What is wasp waist control?
Under wasp-waist control the collapse of a dominant prey species can generate drastic changes at higher, and at lower trophic levels • As fisheries remove substantial numbers of small pelagic fish, need to consider the implications for the other species in the ecosystem Wasp-waist control - a system where one of the intermediate trophic levels is dominated by a single species e.g. small pelagic fishes in up-welling zones.
What is the benefit of more diversity in an ecosystem?
more stability (resilience) - more resistant to disturbance by natural disaster or human interference.
What is an ecosystem?
"a spatially explicit unit of earth that includes all organisms, along with all the components of the abiotic environment within its boundaries"
Describe high latitude salinity
- Low salinity, due to abundant sea ice melting, precipitation, and runoff
How can you measure primary production?
-The amount of carbon dioxide used. -The rate of sugar formation. -The rate of oxygen production.
What is seawater's N:P ratio?
20:1
What temperature is the densest form of water?
4 degrees C
What is photosynthesis?
6CO2 + 6H2O ------> C6H12O6 + 6O2 the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.
How much of the earth is covered by water?
71%
How much of ocean water is moved by subsurface currents
90%
What percentage of ocean water is moved by thermohaline circulation?
90%
reverse osmosis
A desalinization process that involves forcing salt-water through a membrane permeable to water but not to salt. Usually the density would flow from freshwater to saltwater, but in reverse osmosis this is the opposite.
silica (SiO2)
A material formed from oxygen and silicon. SiO2 is an important nutrient for diatoms and other silica-depositing organisms
What is a niche?
A niche is a particular area in an ecosystem where an organism lives • The more niches an area has, the more biodiversity (e.g. coral reefs cover 1% of the sea but have 20% of all marine species)
Eutrophication
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
Parasitism
A relationship between two organisms of different species where one benefits and the other is harmed. Eg. fish and sea lice
Mutualism
A relationship between two species in which both species benefit Ex. The bee and the flower. Bees fly from flower to flower gathering nectar, which they make into food, benefiting the bees. When they land in a flower, the bees get some pollen on their hairy bodies, and when they land in the next flower, some of the pollen from the first one rubs off, pollinating* the plant. This benefits the plants.
ecological niche
A specific role of a species within an ecosystem, including its use of resources, and relationships with other species. The position or function of an organism or a population within a biological and physical environment. The area within a habitat occupied by an organism. The ecological niche is an organism position in the habitat
Transect Belt Study
A way to quantify diversity in coral reefs. Snorkeler/diver swims down the transect line and counts abundance of organisms
What is the ten percent rule?
According to the law, during the transfer of organic food from one trophic level to the next, only about ten percent of the organic matter is stored as flesh. The remaining is lost during transfer or broken down in respiration. Plants utilise sun energy for primary production and can store only 10% of the utilised energy as net production available for the herbivores. When the plants are consumed by animal, about 10% of the energy in the food is fixed into animal flesh, which is available for next trophic level (carnivores). When a carnivore consumes that animal, only about 10% of energy is fixed in its flesh for the higher level.
What is bottom up control?
An energy flow where the very small control the very large. how different components would react to environmental changes or to changes at bottom of the food web So if the phytoplankon decrease in quantity, so will the zooplankton, the forage fish, and the predators.
What is an unstable water column ?
An unstable water column is not stratified, it is well mixed • Salinity uniform with depth, temperature uniform with depth • Dense water continually sinking
Which heterotrophs do not respire oxygen?
Anaerobes. They respire through fermentation. Anaerobic respiration might take place in waterlogged root cells, or in bacteria infecting deep puncture wounds. Example is yeast or Tetnus bacteria.
limiting factor
Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms. Growth of natural populations is usually limited by one or several factors • a limiting factor is one that controls a process, e.g. organism's growth rate. • Growth is not controlled by the total resources available, but by the scarcest necessary resource.
How does size affect species diversity?
As body size grows, diversity decreases
What ocean has the greatest salinity?
Atlantic Ocean
Diversity in many groups of organisms decreases as body size grows... Why is this?
Because the relationship between metabolic rate and body mass. The larger their body, the slower their metabolic rate, and the less chance for speciation. the maximal population abundance (or carrying capacity) that a species can achieve is determined by how much energy is available for consumption
What is the most common ecosystem control observed?
Bottom up control
Name the 3 energy flows in marine ecosystems?
Bottom up, top down, wasp waist
Redfield ratio
C:N:P 106:16:1
What is the energy needed for?
Chemical work: synthesis of complex biological molecules from simpler precursors, • Transport work: energy needed to take up nutrients, eliminate wastes, and maintain ion balance, • Mechanical work: energy required for movement of organisms, cells and structures within the cells.
How do organisms living near hydrothermal vents in the deep ocean get their food?
Chemosynthesis because there is no light for photosynthesis
What areas of the world have the most biodiversity?
Coral reefs, tropical rainforests in South America, Africa. Basically those places close to the equator.
Compensation Depth
Depth at which light intensity reaches a level at which oxygen evolved from a photosynthesizing organism equals that consumed by its respiration. Factors that influence Compensation Depth: the illumination at the surface, the transparency of the water, the biological character of the plankton present, and the temperature. The compensation point was found nearer to the surface as you move closer to the coast, and is deeper in the ocean
Where does most primary production occur?
In the shallows near shore
What drives deep ocean circulation?
Differences in the density of sea water ex. Temperature (thermo) and Salinity (haline). Together, this is called theromhaline circulation
Examples of plankton
Dinoflaggelets, diatoms, cyanobacteria, some jellies
Difference between abundance and diversity
Diversity refers to the different types of the species within an area. Abundance refers to the total amount. You can have 100 butterflys of the same exact type or 100 different types of butterflys. Abundance is the ssame, diversity is different.
what can we do regarding overfishing issues?
Driver = demand for food • Pressure = fisheries - (DPSIR) • Solutions - conservation measures o MPAs o Quotas o Ecosystem Approach to Fisheries o Sustainable Aquaculture
True or false: there are less species in tropics than higher latitudes
False
What is more accurate: a food chain or a food web?
Food web
If there is more production near shore, will you have bluer or greener water?
Greener
Autotroph
Grows on non-organic forms of carbon and energy. E.g. phytoplankton are autotrophs - they use CO2 for their carbon and use sun light for their energy
Describe mid latitude salinity
High salinity, as result of warm, dry - lots of evaporation
How does climate affect diversity
In general, the number of species increases from the poles to the equator with increase in # of niches - tropical rainforests in South America & Africa, & coral reefs have the most diversity - The North and South Poles have least diversity
"Day After Tomorrow" scenario in terms of a halt in Thermohaline Circulation
In the Northern latitudes there's a cooling of water where warm air meets the cold arctic air, which along with the formation of brines creates a sinking effect in water creating the North Atlantic Deep Water and Antarctic Deep Water which physically pushes the water to the deep. North Atlantic Deep Water is what drives the thermohaline circulation. So factors that would cause that not to be formed is an increase in the amount of freshwater formed by glacial melting, warmer temperatures preventing the formation of brines, or a lack of arctic winds cooling water that reaches higher latitudes
Design an experiment
Independent Variable Dependant Variable Control Ex. Testing if diatoms are affected by ocean acidification (a decreasing pH) Independant variable- changing pH levels dependant variable- survival of diatoms control-same water temp, same test tubes, same general makeup of organisms, same salinity
What are some problems with the dilution method?
Is the drop in predator feeding rates linear as we reduce the number of prey? Or is there a threshold (prey abundance) below which the predators stop feeding? • If we dilute the water sample with filtered seawater, are we also diluting nutrients - this may reduce algal growth • Filtration of seawater (to prepare dilutions) can cause release of compounds that inhibit algal growth • How accurate is the theoretical extrapolation to maximal algal growth rate?
What do marine plants need to grow?
Light, nitrogen, oxygen, phospherous, carbon, iron, light, magnesium, salinity, temperature, pH, Co2, water
Describe low latitude salinity
Low salinity, due to high precipitation and runoff
What is top-down control?
Make modification to the top of the food web and these changes trickle down. For example, if you kill the predator, the forage fish will increase. If the forage fish increase, the zooplankton decrease. If the zooplankton decrease, the phytoplankton increase.
Why it is important to understand algal growth?
Microalgae may serve as source of biofuels, cosmetics, food supplements, etc. • Microalgae also serve as food for fish, crustaceans and mollusks/bivalves in aquaculture. • Cultivation of microalgae is based on knowledge about microalgae used for human benefit Biological oceanography... algae - base of the food web • Key to understand oceanic productivity • Ocean health... climate change... • Algal blooms - HABs, Red tides, Green tides • Fisheries
Name causes of species extinction--human and natural
NATURAL= natural catastrophes • earthquake • volcano • tsunami • hurricane • flood • drought • invasives HUMAN IMPACT-• habitat destruction • overfishing • pollution • invasive spp
What are the primary plant nutrients?
Nitrogen, Phosphorus, Silica
Why is diversity so high in coral reefs and rain forest?
Nutrient poor water drives mutualism and symbiosis, as strategies • High productivity & nutrient cycling rates • Finely divided niche
photoadaption
One of the responses of phytoplankton to changes in light intensity. When light intensity is reduced, many phytoplankton will increase amount of chlorophyll, to capture more light. Phytoplankton may also increase the amount of accessory pigments, to match the amount and the wavelength of light available at depth If there is TOO much light, e.g. in shallow water, algae may reduce cellular chlorophyll in response to increase in light intensity To protect their photosystems, phytoplankton may produce more carotenoids (sunscreen pigments) to prevent high light from destroying chlorophyll molecules.
How do humans affect biodiversity?
People can either help or hurt an ecosystem -Protecting an area can increase biodiversity -Deforestation, pollution and over hunting can decrease biodiversity Destruction of habitats through development of houses and buildings, pollution
Most abundant primary producers in the marine environment
Phytoplankton
how do plants capture light energy?
Pigments- excitable organic molecules. Chlorophyll is an example of the primary pigment that captures light.
Who form the basis of the food web?
Primary producers
Chemosynthesis
Process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates. Often these organisms are found in extreme environments with the absence of sunlight
Co-evolution
Process by which two species evolve in response to changes in each other. Coevolution can occur in competitive relationships, sometimes called an evolutionary arms race. - Example: Crab vs. Snail & Bacteria vs. Humans
convergent evolution
Process by which unrelated organisms independently evolve similarities when adapting to similar environments. eg: Tuna (fish) and dolphins (mammals). They are unrelated species living in a similar environment, the ocean. • Faced similar evolutionary pressures.
Caratenoids
Red, orange or yellow pigments. • Absorb light in the bluegreen region. Have photoprotective properties
Eutrophic
Refers to high nutrient and high productivity environments. For example coastal upwelling areas are eutrophic regions
How do primary producers stay in the euphotic zone?
Small size produces a high surface area to volume ratio. This creates a high frictional resistance, which causes you to sink more slowly. Many of these plankton have buoyancy aids like oil droplets (which are less dense than water), gas filled vesicles, and can expel heavy ions. Their body shape also helps with this....long and narrow causes them to sink slowly in a falling leaf pattern. They also form chains to slow their fall and can swim!
Density of seawater depends primarily on which two factors?
Temperature • Cold water is denser than warm water Salinity • The more salt in the seawater, the denser it is
Why do food chains usually have fewer than 5 trophic levels
The 10 percent law is the main reason that most food chains have five or less levels. Because 90 percent of the food chain's energy is lost at each level, the amount of available energy decreases quickly.
BOD values
The BOD value - Biochemical oxygen demand Value is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C
how can we possibly measure algal growth rates if there are zooplankton in the water samples? How can we measure zooplankton grazing rates if the phytoplankton are multiplying?
The Dilution Method
Describe the Med in terms of the Redfield Principal
The Med is 106:28:1 This means that there is a skew here....the Med is P limited and Ultra Oligotrophic, which means nutrient poor.
An indicator of phytoplankton abundance and biomass
The chlorophyll content of seawater
What is the euphotic zone?
The euphotic zone is the layer closer to the surface that receives enough light for photosynthesis to occur. Low nutrient concentrations in the euphotic zone are due to biological uptake and often lead to severe nutrient limitation of phytoplankton during the periods of high water-column stability. The depth varies, depending on such factors as turbidity, supply of nutrients in the water, tidal turbulence, and temperature.
What is a food web?
The feeding relationships between all organisms in an ecosystem
Nutrient Limitations
The growth of natural populations is usually limited by one or several factors. Growth is not controlled by the total resources available, but by the scarest neccesary resource. -The bottleneck principal
What is the biggest threat to biodiversity?
The loss of natural habitat. If we don't protect biodiversity species can become endangered or extinct
Deep chlorophyll maximum
The maximum concentration of chlorophyll below the surface of a body of water. Occurs at minimum light and minimum nutrients needed for primary production. Will really only be seen in a stratified water column. Photoadaption can intensify the dcm. it's a means of photoadaptation. The amount of chlorophyll increases the deeper you go so that it can capture more light. It reaches a maximum before it drops off because it that point it's too deep for light to penetrate any further, so there's no point in investing in chlorophyll
nitrogen fixation
The process of taking atmospheric nitrogen and converting it into a form of nitrogen that's available to use as a nutrient.
primary production
The production of organic matter by autotrophs
secondary production
The use of organic matter by autotrophs AND heterotrophs
Why does a large area have more biodiversity than a small area?
There will probably be more tree species on 100 acres than there will be on 1 acre. This is because a larger plot is likely to have more habitats, hence niches, to support a greater variety of species.
What are primary producers
They are organisms that convert energy from the sun into chemical energy by photosynthesis.
What is a trophic cascade?
Trophic cascades occur when predators in a food web suppress the abundance or alter the behavior of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate trophic level is a herbivore). For example, in eastern North America the removal of wolves has been associated with an increase in white-tailed deer and a decline in plants eaten by the deer. Usually observed in less complex food webs
Heterotroph:
Uses carbon and energy contained in organic matter (food) for growth. E.g. zooplankton consume phytoplankton for their carbon and energy needs. NOT a primary producer
Why is water weird?
Water is weird for a few reasons. First of all, it's less dense in its frozen form (ice floats), which is highly unusual. It also expands when frozen. It also has really high surface tension (which allows little critters to stand on its surface without sinking). Water is also relatively resistent to evaporating, unlike other liquids. In context of the article, water attracts a lot of "pathological science" which is fake science. There's been claims made about water having memory, for example. Basically, all the weirdness can be attributed to the molecular makeup of water (2 hydrogen, one oxygen) and its weak hydrogen bond.
What is an algae bloom?
When an excess of nutrients (like nitrate in fertilizer goes into water bodies via runoff ) flows into a warm water source. Then, algae grows at an alarming rate, blocking sunlight to plants below. They also suck up all the oxygen which can lead to ecosystem collapse and eutrophication of a water body
Atlantic Ocean circulation
Wind driven currents. Example is the Gulf Stream
What is upwelling and why is it important?
Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as "upwelling." Cold, nutrient rich water from the deep ocean rises to the surface and replaces warm surface water.Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients "fertilize" surface waters, meaning that these surface waters often have high biological productivity. Therefore, good fishing grounds typically are found where upwelling is common. It is important to organisms because the nutrients support the phytoplankton and zooplankton.
What are zooplankton?
Zooplankton refers to the small, sometimes microscopic, marine animals. Heterotrophic. Like phytoplankton, they drift in the currents, but they are not primary producers. Often eat primary producers. Examples: Some jellyfish. Planktonic copepods. Portuguese man o' war
Pynocline
a boundary between two layers of water with different densities
Oligotrophic
a condition of a body of water characterized by few nutrients, low productivity, and high oxygen levels in the water column.
What is a food chain?
a hierarchical series of organisms each dependent on the next as a source of food. organisms that transfer food between the trophic levels of an ecosystem using only one species at each level...a simple chain.
Respiration
a process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.
thermohaline circulation
an oceanic circulation pattern that drives the mixing of surface water and deep water • 90% of ocean water is moved by subsurface currents • Density driven currents • Gravity is the driving force • Heavier, denser water sinks • density of seawater » cold vs. warm 'thermo' » fresh vs. salty 'haline' • dense water sinks and less dense water rises as a result • mixing of the depth layers creates an unstable water column
What is a trophic level?
are the different feeding levels of organisms in an ecosystem. Producers are the first trophic level and consumers make up several more
biological nitrogen fixation
biological organisms, such as bacteria or fungus, removing nitrogen from the atmosphere (N2) and adding it into the soil or plant body. In aquatic environments, cyanobacteria are the major free-living nitrogen fixers.
secondary production
biomass generated by heterotrophs
How can we explain latitudinal gradient in species diversity?
by higher productivity or reduced seasonality. more diversity towards equator
Examples of phytoplankton
diatoms, algae, dinoflagellates, formanifera, coccolithophores, sargassum, and cyanobacteria
extinction rate
extinction risk is correlated to size of a species population. • Small populations tend to go extinct more frequently than large ones • In order to increase the population size and avoid extinction, large organisms need large ranges • Thus, the extinction of large species with small ranges becomes inevitable • Amount of space available limits the overall number of large animals that can be present on a continent, and range size (and risk of extinction) prevents large animals from inhabiting small areas.
What are nekton?
free swimming organisms
Where is wasp waist control most prevalent?
generally in nutrient-rich, upwelling systems.
Chlorophylls
green pigment required for photosynthesis that traps the radiant energy of sunlight. Absorbs red and blue wavelengths
Define ecology
looks at the relationship of plants and animals to their physical and biological environments.
Why do currents develop in the ocean?
o Tidal forces - gravitational interactions between earth, moon and sun o Wind - due to pressure differences within the atmosphere o Density - seawater density differences o Massive, slow movements of water in the subsurface
What is the link between rate of metabolic rate and molecular evolution?
organisms with higher metabolic rates have higher rate of change at the molecular level
Autotroph Metabolism
oxygen release, CO2 uptake
Heterotroph Metabolism
oxygen uptake, C02 release
Major primary producers
phytoplankton, algae, seaweed, kelp, seagrasses, diatoms, dinoflaggelets..
biota
plants (flora) and animals (fauna) living in a region
Denitrification
process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere
What happens when ocean surface water evaporates?
seawater becomes saltier & denser & eventually sinks to ocean floor.
artificial selection
selective breeding of plants and animals to promote the occurrence of desirable traits in offspring. Happens accidentally with fishing i.e. larger fish are removed and the fish become smaller over time
food chain
series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
Eu-karyote
uni or multi=cellular organisms with membrame-bound organelles ex. all living things that are not bacteria or archaea
What is a food web?
shows more accurately the network of food chains representing feeding relationships among the biota in an ecosystem. In reality, most organisms feed on more than one type of organism at different trophic levels.
In what kinds of organisms might speciation happen more rapidly?
speciation may occur more quickly in warm environments & in small bodied species
Biological Oxygen Demand
the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
What is speciation rate?
the evolutionary process by which populations evolve to become distinct species.
importance of algae
the majority of primary production in the ocean is performed by algae,
What are ecosystem services?
the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems
generation time
the period between the birth of one generation and the birth of the next generation. Small organisms generally have shorter generation times and are quick to mature and reproduce • These traits may promote speciation through increased mutation and selection events as molecular evolution scales with metabolic rate and thus with body size. • Bacteria can evolve antibiotic resistance in a very short time because they multiply rapidly - probably not possible for species with slower life histories. • "evolutionary clock ticks faster for small organisms" i.e. there are more small species on earth because they speciate faster...
What is biomass?
the total mass of organisms in a given area or volume.
divergent evolution
when two or more species sharing a common ancestor become more different over time. Caused by different environments. Ex. Red fox and kit fox have same common ancestor.
Describe a stable water column
• A stable water column is layered or stratified... no mixing
Why is thermohaline circulation important?
• Climate - Large scale transport of heat, e.g. via the Gulf Stream, between poles & tropics - This circulation affects climate • Ocean mixing - Stirs the ocean from top to bottom (~1500 years) - Mixes in CO2 , O2 , heat & other essential compounds from surface to deep waters & vice-versa - Essential for biota: nutrients, oxygen, CO2
Explain the salinity of the Med Sea?
• Evaporation rate is >> [precipitation & river runoff] • In eastern Med, evaporation is especially high • Creates a pressure gradient, which draws low-salinity water from the Atlantic to the east • In moving to East the water warms, and salinity increases, due to evaporation • Dense water sinks and flows westward as sub-surface flow, that enters the Atlantic through Strait of Gibraltar • Net Med salinity, 38‰ is higher than open ocean salinity - 34 ‰
Global Surface Salinity Variation
• High latitudes - Low salinity, due to... - Abundant sea ice melting, precipitation, and runoff. salinity increases with depth • Low latitudes near equator - Low salinity, due to... - High precipitation and runoff. salinity decreases with depth • Mid latitudes - High salinity, as result of... - Warm, dry - lots of evaporation
Salinity Variation with Depth
• Low latitudes - salinity decreases with depth / • High latitudes - salinity increases with depth • Deep ocean salinity fairly consistent globally • Halocline - separates ocean layers of different salinity
What is ocean salinity affected by?
• Salinity is affected by evaporation, and by mixing of fresh water with seawater • It is also affected by formation of ice • As ice forms in salt water, there is no room in the water crystal for salt (H bonds) • Salt is squeezed out of the ice structure and the resulting ice is less salty than when it began to freeze
Dispersal
• if a species is capable of dispersing across great distances which span variable habitat, more likely that individuals that settle in these new areas will be subject to different selection regimes, leading to new species through natural selection. • Or, great dispersal ability can act against the efforts of natural selection by facilitating gene flow. • Thus, species with greater dispersal ability may in fact have lower speciation rates.
What factors affect biodiversity
•Climate • Area • Diversity of niches • Human activity
