Test 1 Flashcards
Why study marine biology?
It is the study of plants, animals, and other organisms that live in the ocean. Marine life represents an enormous source of human wealth such as food, medicine, raw materials (algae) and recreation.
How can marine organisms create problems for humans?
Shellfish poisoning; ciguatera poisoning; shark attacks; erosion of structures we build (piers, sea walls), fouling of ship bottoms
Fundamentals of Marine Bio
Marine life helps determine the very nature of our planet
Marine organisms produce much of the oxygen we breathe (helps the earth’s climate)
Shorelines are shaped and protected by marine life
- Calcium carbonate sand deposition
- kelp beds
How long ago did life appear in the ocean?
3.8 billion years ago
Animal and plant life?
Extant today, had ancestors that evolved 500 million yrs ago
How old is earth?
4.7 billion years old
Continental Drift
Supercontinent = Pangea: suggests that all the continents had once been joined
- Glomar Challenger 1960’s
- sediment cores (more sediment further away from ridges)
- magnetic signature of crust
Plate Tectonics
Sea floor spreading?
Deep sea vents
Earth’s crust divided into a number of irregular plates;
2-16 cm/yr
Thermophilic and chemotrophic bacteria
Currents
The major wind fields of the atmosphere push the sea surface creating currents
The marine environment is divided into zones according to (3 things)
distance from land; water depth; and whether the organisms are benthic or pelagic
Neritic
pelagic environment that lies over the shelf (also called the coastal zone)
Oceanic zone
Pelagic waters beyond (seaward) the shelf break
Epipelagic
shallowest zone, plenty of light for PS
Mesopelagic
not enough light for PS
Bathypelagic
no light
abyssopelagic;
hadopelagic
flat abyssal plain; trenches
Benthic
live on (epifauna) or buried in (infauna) the bottom some are sessile (attached) some move around (mobile)
Pelagic
up in the water column
away from the bottom
Plankton move at the _
mercy of the currents
Phytoplankton
planktonic plants and other autotrophs are carried from place to place
zooplankton
animal plankton
Nekton
animals that can swim out of currents such as fish, marine mammals, squids, and large jellyfish
Water accounts for _% of the volume of most marine organisms;
Water provides _ and _ _ for
80-90;
buoyancy and body support for swimming and floating; reduced need for heavy skeletal structures
Properties of seawater
Water is a universal solvent
High heat capacity (slow change in temp)
Density temperature relationships (>4oC density increases with decreasing temperature)
<4oC density temperature pattern reverses
Increased viscosity (affects sinking)
Properties of seawater part 2
Heat capacity: In the sea heat is transferred from place to place by
convection (mixing)
subtle conduction (molecular exchange of heat, ie., photons impart energy to water molecules)
Light
Used by marine organisms for vision and PS (euphotic zone)
The _ of the _ _ is determined by how rapidly seawater _ _ and _ it to _ _.
depth; photic zone; absorbs light; converts; heat energy
Factors that diminish quantity/intensity of light available for PS activity include:
suspended sediments concentrated plankton populations clouds, dust, fog angle of incident light/reflection dissolved substances season, time of day, latitude
Temperature
High heat capacity: limits marine temperatures to a much narrower range than land temperatures.
Density _ as temperature _ or salinity _.
increases; decreases; increases
Why is most dense water found at the greatest depths?
Evaporation, cooling, freezing; dense water sinks from the surface
This sinking drives the circulation of water in the deep portions of ocean basins
Pressure
Land organisms are exposed to 1 atmosphere
With each 10m (33 ft) of depth _
1 atmosphere is added
The three most important gases for life in the ocean are
o2, co2, and N
They dissolve in seawater at the sea surface;
Gases dissolve better in cold water;
most solids dissolve better in warm water
Oxygen is added to near surface, seawater by
PS activity
Oxygen is consumed by
Respiration throughout the water column
_ + _ use oxygen as fast as it can be replaced in the oxygen minimum zone (200 - 1K meters)
animal respiration; bacterial decomposition
Adaptations of oxygen minimum zone
larger than usual gills, inactive, hemoglobin adapted to low oxygen concentration