GEOS 212 exam 3

what does ABNJ stand for?

areas beyond national jurisdiction (in reference to our shared ocean)

how many marine species are known? how many are estimated to be alive?

~2 million species are known

~5-30 million species are probably alive

rate of extinction is _________ than the rate of discovery

faster

what are at least 5 physical factors that impact what species can be found where?

light intensity, temperature, salinity, pH, density, depth, pressure, gases (O2 and CO2), nutrients (CO3, Si, Ca), wave action (energy), tides, motion of water (currents), substrate (rocks/sediments on seafloor), water clarity and prey vs. predators

what are the different marine communities?

-coastal (kelp, mangroves, coral reefs)

-open ocean

-deep sea

________ _______ provide structure for communities

food webs

what are the 3 components of life?

1. organic materials (fluids, gases, and tissues)

2. all organisms need energy (photosynthesis, respiration, and chemosynthesis)

3. information (= DNA for most organisms)

what does life in the ocean start with?

primary productivity (chlorophyll)

describe the biogeochemical cycle in simple terms

nutrients are used at the surface of the ocean —> organic matter (poop and dead bodies) sinks and rots, releasing nutrients —>upwelling brings new nutrients up back to the surface

describe the evolution of the atmosphere and life on earth (simple version)

earth forms —> lots of CO2 at first —> ocean forms —> plants form (use up CO2) —> then O2 forms —> animals form —> ozone layer forms (O3) —> then life on earth

describe the parts of the food web (shaped like a pyramid)

primary producers (plants, phytoplankton)

primary consumers (herbivores)

secondary consumers (carnivores)

top predators (eats anything)

what is the most abundant type of phytoplankton in our oceans? what are they made of?

diatoms (single celled plants)

-made of quartz

-100,000 species

what is the 2nd most abundant type of phytoplankton in our oceans? what are they made of?

coccoliths (single celled plants)

-made of calcite

what are the primary consumers (herbivores) in oceans?

zooplankton (copepods, krill larvae, and ciliates) (krill are the most abundant species on earth)

what is competition?

two or more species that eat the same thing

with a decrease in each trophic level, there is a ____ increase in biomass

10x

what is kelp//what is it made of?

-giant algae = seaweed = all cells can photosynthesize

-no leaves, roots or vascular system

-primary producer

what type of environment do kelp live in?

-live in water up to 100 ft deep (shallow continental shelf)

-like cold water (40-70 degrees F) (high latitudes or upwelling coasts)

-can grow up to 2 ft per day (attached to the sea floor)

what are challenges for marine plants that live in up to 100 ft of water?

-must remain near surface for photosynthesis/sunlight

-must stay attached to the bottom

-can’t have rigid trunk because of wave action

what are some solutions to the challenges mentioned above?

-flexible and strong to withstand wave action

-gas bladders to keep leaves (blades/fronds) near surface

-holdfast to attach to bottom

what products are kelp used in?

-toothpaste, ice cream, shampoo, jelly

-source of iodine

-fertilizer

-foam on beer

-kelp harvesting = big business

why are kelp forests important?

-nursery sanctuary//provides habitat and protection —> biodiversity

-kelp is a primary producer —> base of entire food web

what are kelp forests without otters called?

urchin barren food web

-sea otters eat sea urchins and without them, urchins would dominate, consume all of the kelp plants and throw off the entire food web

what are mangroves?

-trees with vascular system (leaves, trunk and roots)

-roots are in mud and in air

-primary producers

where do mangroves live?

-in intertidal zone (between high and low tide) along gently sloping continental shelves

-live in warm water (>70 degrees F) —> low latitudes

what are challenges and associated solutions for a land plant living in the tropical intertidal zone?

-salt (tolerant)

-hurricanes (strong root system and trunk)

-tides/roots under water (pneumatophores)

-reproduction (seedling spikes)

why are mangroves important?

-provides coastal communities with important protection from erosion and destruction from storm surges

-provide habitat protection and nursery sanctuary —> high biodiversity

-they also sequester carbon from the atmosphere

can mangrove and kelp forests be found on the same coast?

nope

what is the main control on productivity?

upwelling

blue whales are a….

secondary consumer

where can you find coral reefs?

-warm, tropical waters

-shallow water (bc of sunlight)

-small waves

-low nutrients (downwelling)

-volcanic islands

-continental shelves

when did corals evolve?

200 million years ago in the warm, shallow Tethys ocean. when the Tethys closed, the coral had to migrate to survive. they now exist near continental shelves and volcanic islands

how can corals migrate to another area?

planktonic juveniles (free floating)

what way do corals grow?

corals grow upwards to stay near the surface as their surrounding island sinks

-fringed coral reef —> barrier reef —> atolls (made of calcite)

how are corals both plant and animal?

animal = polyp

algae (plant) = zooxanthellae

calcite skeleton = rock base

-symbiotic relationship built long ago

how do corals survive in nutrient poor water?

all nutrients get recycled in coral reef food webs

what is the major cause of massive coral bleaching events in recent years?

abnormally warm water temperatures

describe how coral bleaching occurs

under certain environmental stress (warm water), colorful symbiotic zooxanthellae which live in coral body are expelled by the coral host and then the white coral calcium carbonate skeleton is exposed

what happens when corals are bleached?

-they’re more vulnerable to disease

-some diseases are rapid and devastating

describe the problem with ocean acidification

too much CO2 in the atmosphere makes the ocean more acidic and increases the amount of bicarbonate in the ocean which is corrosive to shells and skeletons of many marine organisms as they need carbonate to build their bodies with

what is one way that ocean acidification may affect the open ocean food web?

coccoliths and copepods numbers will drop because there isn’t enough carbonate in the water and baby pacific salmon won’t be able to find food which can also affect fisheries

how is the productivity in open ocean communities?

productivity is local and seasonal (mostly low) in gyres.

-occasional storms stir up nutrients and algal blooms occur

what is the challenge of living in the open ocean?

mobility to find prey and avoid predators

what is the life cycle of fish?

eggs —> larvae —> juveniles —> adults

what are ways the word “fishery” can be used?

can refer to the occupation, industry or season for catching fish

-can also refer to the area of ocean where fish are caught or the business of catching fish

what do fisheries in the US include?

-commercial: catching and marketing fish and shellfish for profit

-recreational: fishing for sport or pleasure

-subsistence: fishing for personal, family and community consumption or sharing

what roles do marine protected areas play?

-increase biomass, fish size and diversity

-larger fish produce more eggs

-export fish to adjacent areas

about what percentage of newly hatched fish make it to adulthood?

1% or less (1 in 1,000-100,000)