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Marine Ecology Exam 1

Terms in this set (184)

What happens at a mid-ocean ridge?
Seafloor spreading
What is formed when plates collide?
Trenches
What are the main primary producers in the ocean
Algae, seagrass, phytoplankton, mangroves
What causes wind?
Uneven heating of the earth's surface
What is a mixed tide?
Two unequal high and low tides daily
What is a diurnal tide?
A single high and low tide daily
What is a semi-diurnal tide?
Two high tides and two low tides each day
Which is richer in nutrients: cold water or warm water?
Cold
What drives marine secondary productivity?
Zooplankton
What are the 3 phases in the history of marine ecology?
Exploration and description (1700s)
Experimental manipulation (1960s)
Integration and application (modern day)
What are ocean zones going from the surface down:
Pelagic
Oceanic
Epipelagic
Mesopelagic
Bathypelagic
Abyssalpelagic
Hadalpelagic
What are the benthic ocean zones starting at the beach:
Littoral
Sublittoral
Bathyal
Abyssal
Hadal
Definition of biogeography
Global distribution of species
What defines biogeography for species groups?
Chemical and physical parameters
Trades biome:
Defined by winds; broadscale wind patterns
Westerlies biome:
Defined by local wind speed and light intensity (more localized than trades)
Polar biome:
Defined by surface-reduced saline water; ice
Coastal biome:
Driven by coastal processes (currents, tides, coastal morphology, etc)
What were the first 3 biome divisions?
Polar, temperate, and tropical
What were Longhurst's 1998 divisions of marine environments divided based on?
Phytoplankton concentration, chemical & physical parameters
What is an endemic species?
A very localized species that is only found in a specific environment
What can endemism help explain?
Evolutionary history, speciation events
How much solar radiation is blocked by the ozone layer?
95%
How much solar radiation is absorbed by earth?
40-45%
What drives photosynthesis?
Solar radiation
Marine plants and algae are responsible for how much of the world's stored carbon?
50-70%
What are the differences between marine plants and algae?
Marine plants: Chloroplast in leaves, stem with vascular system, roots for nutrient and water
uptake

Algae: Holdfast for attaching to substrate, Chloroplasts throughout entire structure, stipe, pneumatocysts, blades (not leaves), gas bladders for buoyancy
How does photosynthesis differ between algae and marine plants?
Plants have chloroplasts only in their leaves and photosynthesis only occurs in the leaves, however in algae the chloroplasts are present throughout and therefore photosynthesis occurs throughout
Photosynthesis light reactions:
Inputs: water, light
Outputs: Oxygen, heat, ATP, water, 12 NADPH

Light produces energy
Photosynthesis dark reactions:
Inputs: ATP, NADPH, CO2
Outputs: Glucose, water, heat

No light needed; uses the output from light reactions to produce heat
Photosynthesis formula
Carbon dioxide + water -> glucose + oxygen
Cell respiration formula:
Glucose + oxygen --> carbon dioxide + water + ATP
What are some photosynthetic pigments?
Chlorophyl a, b, and c
Beta carotine
Phycocyanins
Photosynthetically Active Radiation (PAR):
light intensity in the 400-700 nm wavelength band that is used by plants in photosynthesis
What determines the rate and extent of photosynthetic activity?
Natural light
About how deep in the ocean does photosynthesis occur?
200 m
Light attenuation:
Reduction of light intensity as depth increases; affected by amount of particles in the water
Colored dissolved organic matter (CDOM):
Discolors water; usually humic-rich
Can improve/worsen with water mvmt
What are some of the nutrients needed for photosynthesis?
Calcium, silica, nitrates, phosphates, sulfur, strontium, potassium, manganese, iron, sodium, magnesium
Eutrophic:
High nutrients
What are some effects of eutrophication?
- Increase in the rate of supply of organic matter to an ecosystem ( can cause hypoxic/dead zones)
- Process of change, not a trophic state
- Reversible and not always detrimental
- Both natural and man-made
- NOT associated with the food web
Oligotrophic:
Cold, clear, low nutrients
Mesotrophic:
Some nutrients
What is algal growth dependent on?
- Material and energy gains (photosynthesis)
- Material investments (Skeleton formation, production of storage compounds, forming reproductive materials)
- Energy and material losses (mvmt, buoyancy, excretion, osmoregulation, nutrient uptake, respiration)
Formula of algal growth:
Growth = material and energy gains - material and energy losses
What are the main macronutrients associated with algal growth?
Carbs, protein, fat, nucleic acids
What limits algal growth?
Nutrients (main factor), light, and temperature
What nutrient is the limiting factor in estuaries?
Phosphate
What is the Redfield Ratio?
C:N:P 106:16:1
POM:
Particulate organic matter
DOM:
Dissolved organic matter
Gross primary production (GPP):
The total primary production of an ecosystem.
Net primary production (NPP):
The gross primary production of an ecosystem minus the energy used by the producers for respiration.
Net ecosystem production (NEP):
A measure of the total biomass accumulation during a given period
What drives seasonal trends in primary production?
Nutrient availability
What 4 factors drive primary production in the oceans?
Light: 200 m and above
Nutrients: Typically exhausted in upper layers
Stability: to allow algal growth at the surface
Mixing: to replenish nutrients from lower depths
Is primary productivity around the equator high or low?
Low
What are the controlling factors of primary productivity in the various zones?
Trop/subtrop: Low surf water nutrients (low PP)

Polar: significant mixing of deeper and surface waters = more nutrients. Short seasons b/c of light availability

Temperate: Variable due to seasons (PP is generally high)
Anticyclonic gyres:
- convergence and downwelling
- low nutrients = less PP
- tend to move water to center of gyre
- no mixing of layers
Cyclonic gyres:
- divergence and upwelling
- high nutrients = more PP
- tend to pull water out of gyre, allows deeper water to rise
Upwellings:
-bring up nutrients
- common around coastal regions
- very important for high PP
- greatest PP is over continental shelves
- pushes away warm water and cold water rises
Globally, is phytoplankton productivity higher or lower than macroalgae?
Much higher
Primary productivity measurement methods:
Bottle incubation: light/dark reaction; not always real world variables

Radiocarbon labeling: C14; can't tell difference between GPP and NPP

Oxygen consumption: Units are difficult to work with; can differentiate between NPP and GPP

Electrodes: good for trends; a lot of calibration needed
How is primary productivity measured?
Estimated by the measures of the fluxes of carbon dioxide and/or oxygen
Remote sensing to measure PP:
- using satellites or aircraft
- uses color of the water to estimate conc. of pigments in the water
- best for large-scale studies
- LIDAR (light detection and ranging from aircraft)
Fluorescence measurements of chlorophyll:
Instrument sends out pulses of light & fluorescence that is generated is measured
What are microbes?
Prokaryotes (no membrane-bound organelles)
Bacteria (No nucleus)
Archaea (Extremophiles)
Decomposition:
The breakdown of organic materials into inorganic ones
Why is the microbial loop important?
Ecosystem functioning: decomposition, nitrogen fixation, denitrification, nitrification, primary production, mvmt of CO2
What is the surface area-volume relationship?
The biological biomass spans 21 orders of magnitude;
small size = larger surface area to volume
Which is larger, a bacteria or a virus?
Bacteria is larger
Why are microbes able to assimilate low concentration nutrients?
They have a very high surface area to volume ratio
What controls a microbe's metabolism per unit biomass?
Surface-to-volume relationship
What is an advantage of bacteria being able to divide quickly?
Can respond very rapidly to changing conditions
How can microbes survive extreme conditions?
Can slow down metabolism and change morphology to become resting cells
What is remineralization?
Decomp. (from metabolism/respiration) results in the production of inorganic carbon dioxide, nitrogen (ammonium), and phosphorus (phosphate)
What makes up detritus?
Dead organic matter, biological particulate, marine snow
DOC
Dissolved organic carbon
What is biological particulate?
- organic macromolecules such as cellulose, proteins, chitin, fats
- dead organisms
- sloppy feeding byproducts
- organic matter from terrestrial systems
What is a big pool of nutrients taken up only by microbes?
DOM
What are the 5 important microbe groups?
Bacteria & archaea
Viruses
Algae
Protozoa
Multicellular zooplankton
What are some methods to ID microbes?
Size
Functional group
Species
What are chemolithotrophs?
Autotrophic microbes deriving energy for growth from inorganic reduced compounds and capable of fixing atmospheric CO2 for their carbon demand
What are organotrophs?
Heterotrophic prokaryotic microbes deriving their energy and carbon from decomp. and respiration of organic material produced by autotrophic organisms
How do organotrophs obtain energy?
Respiration of organic material;
rely on organic C fixed by others
What are organotrophs able to break down?
Nearly all naturally produced organic material and many synthetic chemicals
What are osmotrophs able to do?
Take up dissolved organic matter (DOM) from their environment
How do chemolithotrophs obtain energy?
Autotrophic; solely by oxidizing reduced inorganic nitrogen compounds and their carbon
How do chemolithotrophs create new biomass?
By synthesizing carbon from CO2 with new chemical energy
2 groups: ammonia oxidizers & nitrite oxidizers
What are 2 common marine prokaryotes?
Cocci (spherical)
Rods (elongated)
Molecular ecology in IDing marine prokaryotes:
Using molecular markers; can follow single or multiple genes, sometimes whole genome
Use 16s rRNA snd ITS region
What are some controls of growth rates for bacterial populations?
Substrate type & availability, nutrient availability, temperature, salinity, pressure
What are some mortality-controlling factors of bacterial populations?
Protozoan predation, viral mortality, competition, starvation
R-selected ecotypes:
Produce many offspring; low parental investment
K-selected ecotypes:
Produce few offspring; high parental investment; reproduce slowly
Would a low nutrient environment be more favorable to R-selected or K-selected ecotypes?
K-selected; more stable long term
What controls the patchiness of bacterial communities in the ocean?
Currents and production history down to 300-500 m
Marine bacterial communities:
Generally highly dynamic with lots of species turnover and many have narrow niches and compete for resources
Bacterial communities are generally stable over what timeframe?
Months
What is a bacteriophage?
A virus that attacks bacteria; helps control populations
What are some characteristics of marine viruses?
- small
- need a host
- contain RNA or DNA
- no independent metabolism or repro capacity
- follow rapaport's rule
What is Rapaport's rule?
Highest diversity near the equator and lessens towards the poles
Lytic virus life cycle:
Infect cells --> replicate --> release into environment
Lysogenic virus life cycle:
Infect cells --> insert genome into host genome --> replicate in host until triggered to release
Chronic virus life cycle:
Host and offspring produce and release new viral parts without completely lysing (less common)
What are marine protozoans?
Unicellular eukaryotes
Individual or colonies
What is a mixotroph?
Can get energy from photosynthesis AND organic compounds
How do protozoans reproduce?
Binary fission or conjugation
What are some characteristics of flagellated bacteriovores?
- eat bacteria
- 1-4 flagella: propulsion, generate feeding currents, sense surroundings
Microzooplankton:
Ciliates (bacteriovores, herbivores, predatory, or micotrophs)
and larger dinoflagellates
Holoplankton:
Organisms that live their entire lives as plankton
Meroplankton:
Planktonic for only larval stages of life cycle
What is an important ocean process that occurs in the top 100m of the ocean?
1/2 of daily photosynthetic production
Solubility carbon pump:
- Transports dissolved inorganic carbon
- Controlled by CO2 dissolubility and large-ocean circulation
- Important in bringing nutrients to the deep ocean
Biological carbon pump:
- Driven by microbial production & consumption of organic matter (organic carbon)
- Dependent on microbial loop
What are some challenges of microbial oceanography?
1. developing sampling strategies for the complex habitat (small)
2. development of ecological models to netter understand diversity and connections with the biogeochemical cycles
What is the general definition of biodiversity?
All life on earth
What are the 3 main threads of biodiversity?
Ecological (biomes, ecosystems)
Organismal (kingdom, phylum, etc)
Genetic (populations, individuals, genes)
Why is it difficult to use fossil records for long term biodiversity estimates?
Many gaps, many organisms do not leave fossils (ex gelatinous organisms)
What are some consequences of a species going extinct?
- new niche that can be filled
- no control on their prey
- allows for increases in biodiversity
About how many species have been found globally?
2 million, mostly terrestrial b/c easier to study
Why is it difficult to get an accurate number of species?
- many species look similar
- sexual dimorphism (males & females sometimes recorded as different species)
- only ~5% of world's oceans have been studied
True or False: There is higher biodiversity around the equator
True
What is an example of a pioneer species?
Red mangroves
How can organisms play an important functional role in an ecosystem?
Pioneer species (start primary production, anchor sediment, provide habitat)
Encrusting suspension feeders
When is functional diversity of an ecosystem higher?
When the number of functional groups is higher and/or the numbers of members of each functional group is higher
What would theoretically make an ecosystem more robust to change and environmental stress?
Higher functional diversity
What do low-diversity habitats have?
High abundances of single-species, which are variable in space and time
What affects the abundance of an organism?
Food availability, competition, over-harvesting, predation, natural disasters (anything that affects pH, temp, salinity)
Which geological event resulted in a huge amount of diversification?
The Cambrian explosion
How is body size important?
Important to function, ecology, physiology, & evolution of organisms
What is the pattern of body size over time?
Precambrian: most are small
Mesozoic: most are large
Today: largest ever
What is Cole's Rule?
Many animals have tended to increase in size over time
What is genetic diversity?
The variation in the genetic composition of individuals in a population, community, or species
What are some of the processes that can result in evolution?
Chromosomal/sequence mutation
Physical/behavioral isolation of populations
Why is genetic diversity important?
Allows individuals to adapt to different conditions. High genetic diversity increases the ability of populations and species to survive major changes in their environment
What is species diversity?
The variety of species in a particular habitat or ecosystem
Is the diversity of smaller organisms more well known than larger ones?
No, lesser known
What is a gene pool?
The total number of genes in a particular population or species
What is population diversity?
Robustness of a gene pool
What is ecosystem diversity?
The variation in all living and non-living things in a particular geographic or ecological region
What is an ecosystem comprised of?
Unique combinations of animals, plants, micro-organisms, & physical characteristics that define a location
What are some examples of marine ecosystems?
Coral reefs
Mangroves
Estuaries
Hydrothermal vents
Tide pools
Seamounts
Beaches
Rocky shores
Ridges
Wetlands
Artificial structures
Open ocean
Cold seeps
Brine pools
Polar regions
Kelp forests
deep ocean
Where is productivity high in the Atlantic ocean?
On continental shelves and marine ridges; biodiversity is high
What are the main threats to biodiversity in the Atlantic Ocean?
Over-exploitation of fisheries
Pollution
Lack of info & monitoring in open waters
Which seas in the Arctic have a wide diversity of pelagic & benthic organisms?
Norwegian and Barents seas
What are the main threats of biodiversity in the Arctic Ocean?
Extensive fishing
Global warming (ozone hole)
Accumulation of pollution by atmospheric & oceanic circulation
Exploration for & development of oil/gas reserves
When was the first quantitative measure of deep sea diversity?
1967, by Hessler & Sanders
When were hydrothermal vents discovered?
1977, by Bob Ballard in Alvin
How long does a hydrothermal vent remain active?
7-10 years
What causes cold seeps?
Gas hydrates coming from the sediment
What are methane gas hydrates?
Methane gas trapped within ice
Where are cold seeps found?
Found in areas where gases (methane, hydrogen, sulfide) and oil seep out of sediments;
found along continental margins
What conditions allow for the formation of methane hydrates?
High pressure & low temp
Calthrate:
Chemical substance where 1 of the molecules form an open lattice enclosing molecules of another material without forming chemical bonds between the 2 materials
Methane:
Made by archaebacteria which in this case breaks down organic material buried deep in ocean sediments producing methane
Why is marine biodiversity so important?
Oceans occupy 70% of earth
Over 50% of humans live in coastal zones
90% of our marine-living resources drawn from the coast
What resources do marine environments provide us with?
Natural beauty (recreation)
Goods (food, medicine, drugs, energy)
Services (moderation of climate/weather extremes, processing of waste)
Employment (fisheries, tourism)
Stewardship/cultural identity
Education on evolution & ecology
What is ecosystem functioning?
Comprises both the ecological & evolutionary processes, and the individual components, within a system
What is a mass extinction?
An event in which very large numbers of species die out in a relatively short period of time
How many mass extinctions have occurred in earth's history?
5; driven by geological and astronomical processes &took millions of years to take their toll on biodiversity
How much faster is the current extinction rate?
50-100 times the natural rate
What are the main threats to marine biodiversity?
Habitat destruction & fragmentation
Over-exploitation of resources
Pollution
Invasive species
Climate change
Population growth
What are some effects of invasive species?
Threaten native ecosystems
Disrupt & degrade whole ecosystems
What are some examples of invasive species?
Asian swamp eel (S. Fl waterways)
Lionfish (Atlantic)
Green mussels
How do population growth & pollution reduce aquatic biodiversity?
- noise & crowding from humans
- nitrates & phosphates from fertilizers (eutrophication)
- Pollutants from industrial & urban areas
- plastics (microplastics)
Which areas are susceptible to rising sea levels?
Coral reefs
Low-lying islands
Highly productive coastal wetlands
What is a fishery?
Conc. of a particular wild aquatic species suitable for commercial harvesting in a specific area
What is a fishprint?
The area of ocean needed to sustain the fish consumption of a person, country, or the world
Which group or organisms is most threatened with extinction due to human activity?
Marine & freshwater fish
Which is having a larger impact on the oceans: fishing or climate change?
Fishing
What is commercial extinction?
No longer economically feasible to harvest a species
What is local extinction?
The extinction of a species in a particular region
What are some consequences of biodiversity loss?
- reduced capacity of ecosystems to respond to disasters
- accelerated global climate change
- economic loss
- social/political instability
- human existence
How can biodiversity loss be prevented?
Research
Legislation
Education/awareness
Sustainable use of biodiversity
Integration/co-ordination
What is often the limiting factor in ocean exploration?
Available technology
What tools are becoming available for oceanic study?
- improved sample collection
- continuous observation, in-situ labs, instruments
- AUV/ROV , manned submersibles
- satellites, buoys & sensors
- molecular taxonomy
What opportunities exist in the conservation of biodiversity?
- preservation of habitats & ecosystems; marine parks and biosphere reserves
- applying precautionary principles
- developing global awareness & networking programs
What is the precautionary principle?
Shouldn't let things occur and then try to fix them as the happen (Rachel Carson)
Sustainable use in biodiversity:
- new management practices; policies & guidlines
- sharing knowledge (ex. MPAs)
- international agreements (ex. Caribbean coral conservation)
Census of marine life (COML) 1999-2009:
- Sloan was funding source for US ($650M)
- 2700 scientists; 80 nations; 540 expeditions
What were some of the discoveries made during COML?
- discovery of shrimp species thought to be extinct for last 50 million years
- Loricifera living at depths with no oxygen
- Sooty Shearwater (bird) travels 40k miles from pole to pole each year
How many seamounts have been studied?
Less then 300, and mostly macro-fauna based
What 2 questions were addressed about seamounts during COML?
1. What factors drive community composition and diversity on seamounts, including any differences between seamounts and other habitat types?

2. What are the impacts of human activities on seamount community structure and function?
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