eps sci 15 lab 7

which plankton are likely to contribute to which type of biogenous sediment?

-diatoms, radiolarians = silicious ooze

-coccolithophores, foraminiferans = calcareous ooze

why are preserved remains of copepods and dinoflagellates rarely found in young or old marine sediments?

-don't have mineral skeletons

-exoskeletons/cell walls are composed of organic materials, quickly decomposed by saprotrophic bacteria

which latitude has greatest total organic primary productivity

north temperate

why is tropical productivity low and flat?

-develop permanent thermocline which forms a barrier to vertical mixing and the resupply of nutrients to the sunlit surface layer

-limited year-round by nutrients

why is the north polar-latitude productivity sharply spiked during June to august?

-continuous illumination for 3 months during summer and doesn't have a thermocline in water temp and density changes very little with depth

-limited by seasonal sunlight

red tides

algal blooms

-common via nutrient-rich influxes

-likely that phytoplankton pop growth leads to zooplankton pop growth: grow first in response to direct use of nutrients, zooplankton lag phytoplankton because their growth depends on number of phytoplankton

-high after rainy weather near treatment plants because it releases the nitrate rich water that is normally over filtered

what is the volume of productive ocean if we consider the euphotic zone to globally average 70-m deep?

what is the productive volume as a percentage of the total ocean volume?

70m (convert to km)

-multiply by ocean surface area

-km^3

-answer of above multiplied by ocean volume x 100%

what is the total annual marine carbon production using average oceanic productivity rate?

average oceanic productivity (box) x average oceanic productivity rate (given in question, basically a conversion) x 1 yr (because it's annual) x ocean surface area

if every g of carbon produced was bound into 2.5g of (element) what is the total annual marine (element) production?

total annual marine carbon production x 2.5g element / 1 g carbon

what is the world annual-consumption of seafood if every person consumed 100g per day?

2007 world population = 6.6 x 10^9 people

100g/person/day x world pop x 365d/year

what is the necessary primary-producer biomass to support this annual seafood consumption if 10,000 kg of primary producers are necessary to maintain 1kg tuna

world annual consumption of seafood x 1 kg(tuna)/1,000g(tuna) x 10,000kg(pp)/1kg(tuna)

how does that compare to estimated total annual biomass production? would the daily global diet of 100g of tuna be possible?

it is greater than the total annual marine biomass production-- not possible to have that diet

O2:organic carbon production

6:1

respiration

consumption of organic matter and O2 for energy

net primary productivity

photosynthesis - respiration

NPP = GPP - R

gross primary productivity

photosynthesis production not including respiration

GPP = NPP + R

at what depth is O2 production the greatest?

30m

at what depth is respiration greatest

0m, at surface

compensation depth

where photosynthesis = respiration

-NPP = 0

euphotic zone

above compensation depth

-where photosynthesis > respiration

disphotic zone

below compensation depth

-where photosynthesis < respiration

phytoplankton

OG source of food for all higher marine orgs

pelagic

surface waters

-can't swim, limited ability

-nekton = lateral and vertical movement

benthic

live on, in, near seafloor

-on = epifaunal

-near = mobile or attached to fixed structure

-in = infaunal

biotic community

-producers, consumers, decomposers

autotrophs

producers

-make complex organic compounds from simple inorganic compounds + external inorganic source of energy

heterotrophs

consumers

-feed on auto or heterotrophs

-used organic carbon compounds for growth

saprotrophs

heterotrophs that are decomposers and recyclers

-dead orgs and waste = energy

plankton

phyto = autotroph

zoo = heterotroph

bacterioplakton = sapro or auto

food chain

simple arrangement of orgs according to predation

food web

complex network of interactions among orgs

-divided into trophic levels

primary productivity

g carbon/m^2/year

-use chlorophyll to absorb sunlight, make glucose

limiting nutrients

phosphorus and nitrogen

-upwellings bring nutrient replenishment, as ekman transport moves water away from coast and equator

-thermohaline stratification prevents nutrient replenishment = gyres

red field ratio

106C: 16N: 1P

-to predict amount of CO2 available for conversion to organic matter given set amount of N and P