Oceanography Exam #4

What is a longshore current?

zig-zag movement of water downcoast along the shoreline

What is longshore drift?

Caused by a longshore current, downcoast along shoreline. Move sediments

What is a rip current 

strong, narrow currents moving directly offshore

How do you escape a rip current?

Swim to the sides at a ninety degree angle. Parallel to the coast

What are the two types of deltas called?

Birdsfoot and Arcuate river delta

What is an example of the birdsfoot river delta?

The Mississippi river delta

What is an example of a Arcuate river delta?

The Nile River

Characteristics of the Mississippi river delta

• Deposition is greater than erosion

• Triangular deposits of sediments

Characteristics of the Nile river delta

• Erosion is greater than deposition

Isostatic sea level change

when lithospheric plates depress (change) due to (for example) massive ice sheets. So the sea level changes because of the sinking of the lithospheric plates

Eustatic sea level change

When the sea level change occurs over the whole Earth as a result of sea water volume change. Melting of polar ice

What is hard stabilization?

hard structures built to protect a coast, “armoring of the shore”

Examples of hard stabilization

Groins/Groin fields- used to trap sand and prevent it from going upstream but a disadvantage would be an increase in erosion on the downstream side. More examples: Sea walls and breakwaters

What is soft stabilization

Restrict construction of property in areas prone to coastal erosion and sea level rise. Along with Beach replenishment(replace lost sand) It is very expensive!

How does temperature affect the ocean/sea levels?

• allows for water’s thermal contraction or expansion - eustatic sea level change! 

• When water cools, this causes the sea to contract which lowers sea levels. When water heats up this causes the sea to expand which raises sea levels.

Does freshwater runoff cause an increase or a decrease in salinity?

This process causes a decrease in salinity levels

Does evaporation cause an increase or a decrease in salinity?

Causes an increase in salinity levels

What does it mean when water is isohaline?

Well mixed in salty and fresh water

What are Estuaries?

Partly enclosed body of water, freshwater runoff from a river dilutes salty ocean water.

What is a bar-built estuary?

Lagoon separated from ocean by sand bar or barrier island

What is a tectonic estuary

Faulted or folded downdropped area now flooded with ocean (e.g. San Andreas fault)

What are lagoons?

protected, shallow bodies of water landward of barrier islands. Formed by bar-built estuaries. Restricted circulation with the ocean.

How many distinct zones are in a lagoon?

3 distinct zones

What is the salinity at the head of the lagoon?

Freshwater(no salinity)

What is the salinity is the middle of the lagoon?

Transitional zone(a mix of salt water and freshwater)

What is the salinity level at the mouth of the lagoon?

Salty/saltwater zone

What are the two types of coastal wetlands?

Saltwater marshes and mangrove forests

Where can saltwater marshes be found?

30-65 degrees latitude along the coast

Where can mangrove forests be found?

Below 30 degrees latitude(tropics)(found in the Caribbean, Southeast Asia, and Florida)

What are some characteristics of Saltwater marshes?

Support salt-tolerant grasses and other halophytic plants

What are some characteristics of Mangrove forests?

• Contains salt-tolerant mangrove trees, shrubs, and palms

• Mangrove trees have a tripod root system

Why are wetlands important?

• Nature’s kidney

• filter out terrestrial runoff

• Protect shorelines from erosion and hurricanes

What is NASA’s definition of life? 

Life is a self-sustained chemical capable of undergoing Darwinian evolution

What is the Linnaeus system?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

What are the 3 domains of life?

Bacteria, Eukarya, and Archaea

Which domain contains a peptidoglycan cell wall?

Bacteria

What are Autotrophs?

Make their own food

What are Heterotrophs?

They consume other organisms for the carbon

What is phototrophy?

process by which an organism produces food (usually from inorganic substances) using light as the source of energy. Close to the surface of the ocean

What is chemosynthesis?

a process by which Bacteria or Archaea synthesize organic molecules from inorganic nutrients using chemical energy released from the bonds of a chemical compound(oxidation). Can be found in the deep sea.

What is primary productivity?

conversion of carbon dioxide into organic matter (usually sugar)

What affects primary productivity?

• Nutrient Availability

• Solar Radiation: up to 100 meters

What is the biological pump?

The way in which carbon dioxide is removed from the euphotic zone to the seafloor

What are plankton?

Floaters, move with currents.

Autotrophic plankton, Phytoplankton(not all phytoplankton are autotrophic), zooplankton, bacterioplankton

What are Nekton?

• Any organism that swims and controls where it is

• This is what most sea creatures are

What are Benthos?

• Bottom dwelling organisms

What are epifauna?

• live on the surface of the seafloor, attached to rocks or moving along the bottom (e.g. bivalves, corals, starfish)

What are infauna?

• live buried in the sand or mud, discarded shells (e.g. worms)

Define Pelagic

 Open sea (Marine snow-poop rockets, etc.) this is about 2% of sea creatures

Define Benthic

Sea floor; majority of sea creatures 98%

The ratio of surface area and volume and what that it means for organisms in the ocean.

Have a higher surface area to volume ratio to resist sinking: villi and oil in micro-organisms

What’s the ratio of bacteria to viruses in the ocean?

1:10

What is a trophic level

feeding stage

What is the energy transfer percentage in food chains and food webs?

10% to the next trophic level(passive energy)

What are some issues affecting marine fisheries?

Overfishing, by-catch(accidentally capturing unintended species)

What are some adaptations that allow for deep sea creatures to live in the deep-sea?

Large sensitive eyes, Large and sharp teeth(to capture prey), Expandable bodies, hinged jaws

 Why do marine organisms swim?

To avoid predators and catch prey(eat)

Characteristics of fish with a rounded fin

• Slow

• Maneuverable

• Flexible

Characteristics of a fish with a forked fin

• Fast

• Ok maneuverability

Characteristics of a fish with a truncate fin(triangle)

• Fast

• Ok maneuverability

Characteristics of a fish with Lunate fin

• Fast

• Limited maneuverability

• Rigid

• Ex: Tuna Fish

Characteristics of a fish with a Heterocercal fin

• Top heavy

• Causes lift

• Limited maneuverability

• Ex: shark

Why do fish form schools

• To seem bigger to predators

• Used for reproduction

What are two methods of feeding?

Lungers and cruisers

What is an example of a fish that lunges at its prey?

grouper

What is an example of a cruiser?

Tuna fish

What are different ways animals stay afloat in the oceans?

• Rigid gas containers

• Swim bladder(slow-moving fish) 

• Active swimming(trapping water and using to to move themselves/expelling it)

• Higher surface area to volume ratio

What are the different orders of marine mammals

• Order Carnivora

• Order Sirenia

• Order Cetacea

• Suborder

• Suborder

Characteristics of Order Carnivora

• sea otters, earless seals, etc. Have prominent canine teeth

Characteristics of Order Sirenia 

• Manatee and Dugongs. Herbivores and paddle like tails

Characteristics of Order Cetacea

• whales, porpoises, and dolphins

Characteristics of Suborder Odontoceti(toothed)

• dolphins

Characteristics of Suborder Mysticeti

no teeth- baleen made of keratin

What is coral?

marine animals that live in colonies, often forming reefs

What are the three main types of corals?

• Fringing reef

• Barrier reef

• Atoll reef

Describe a fringing reef

reef that is attached to the shore of an island or continent with no open water lagoon between the reef and shore.

Describe a barrier reef

Reef that has been separated from land, parallel to a lang mass and encloses a lagoon.

Describe an Atoll reef

Ring-shaped coral reef that grows upward from a submerged island and encloses a lagoon 

What are shallow-water reefs?

• Less than 30 meters

• Requires access to light so zooxanthellae can photosynthesize

What are mesophotic reefs?

• Between 30 meters and 150 meters

• Adapted to lower light

• Enough to photosynthesize and consume plankton

What are deep-sea corals?

• Greater than 200 meters

• No access to sunlight 

• Solely rely on plankton and detritus 

• Adapted to cold water

• Produce its own pigment

What are the roles of coral reefs?

• Habitat 

• Food source

• Breeding grounds

• Shelter

• Shoreline protection

• Fisheries

• Tourism 

• Medicine

What is coral bleaching?

When the zooxanthellae are expelled from the tissue of coral(can only survive without zooxanthellae for 10 days) due to stress/temperature change by 1-2 degrees Celsius

 What are some threats to coral reefs?

Anchoring

Sunscreen

Why are oceans important to climate change?

The ocean has absorbed most of the heat from the greenhouse effect!

What effects can increased marine heatwaves have on coral reefs and hurricanes?

Cause more corals to die and cause stronger hurricanes

What are three ways in which climate change affects the oceans?

• Drought 

• Precipitation 

• Warmer waters

What is ocean acidification

by adding carbon dioxide to seawater we are acidifying the ocean = lowering seawater pH!

dissociates into hydrogen and bicarbonate ions.

What are the different types of marine pollutants?

Antifouling paint, Petroleum, Sewage, Agricultural runoff, dredging, Microplastics, and Plastics

Affects of Antifouling paint

Contains copper and tributyltin which are toxic and is used to keep barnacles and other marine creatures from attaching themselves to the bottom of a boat.

Affects of Petroleum

Oil spills and leaks, ship discharge, and natural seeps from sea floor. Oil is a natural substance consumed by microbial decomposers.

Affects of Sewage

combination of liquid and solid natural materials. As population increases, sewage increases

Affects of agricultural runoff

Fertilizer run off, contains nitrates and phosphates

Affects of dredging

act of removing sediment from the seafloor, can damage reefs

Affects of microplastics and plastics

Microplastics: less than 5mm 

When plastics decompose they release toxic chemicals 

What is eutrophication, and what are its effects on marine ecosystems?

increased load of nutrients to estuaries and coastal waters (NOAA) which leads to algal blooms (some can be harmful) and hypoxic (little oxygen) or anoxic (no oxygen) conditions.

What is biomagnification, and why is it a concern in marine food webs?

the process by which a compound (such as a pollutant) increases its concentration in the tissues of organisms as it travels up trophic levels

What are three practical ways YOU can reduce human impact on the oceans?

• Reef safe sunscreen 

• Conserve electricity

• Stop using bleach or harsh chemical cleaning products

Shore

the zone that lies between the low tide line and the highest area on land affected by storm waves

Coast

extends inland as far as ocean related features are found