Intro to Marine Science

Intro to Marine Science and Oceanography

Essential Question: What factors in the ocean impact marine organisms?

Open Ended

What is one thing from the video that stuck with you?

Oceanography vs. Marine Biology

• Oceanography: The study of oceans and its phenomena; i.e. waves, currents, tides, etc.

• Marine Biology: The study of living organisms that inhabit the sea and their interactions with each other

For marine organisms, the physical environment includes

• Water temperature

• Salinity

• Water pH

• Sunlight

• Currents and Tides

• Waves

• Sediment type and more!

The physical enviroment includes all abiotic (nonliving) and biotic (living) factors present in that enviroment

Open Ended

Look at this image. What are some abiotic factors present in the photo?

Poll

Look at the same photo. Which of the following is a biotic factor?

• The water temperature

• How salty the water is

• The school of fish

• The type of sand

Salinity 

The measure of the dissolved salts in seawater.
Usually expressed as the number of grams of salt left behind when 1000 grams is evaporated, known as ppt (parts per thousand) or as a percentage.
When seawater evaporates, the ions left behind combine and form various salts.
Sodium and Chloride account for 85% of all dissolved materials in saltwater.

Salt in seawater comes from:

• River Runoff 

• Weathering of rocks

• Hydrothermal vents

• Volcanos

Other types of water

• Estuary: The tidal mouth of a large river, where the tide of the ocean meets the stream of a river

•  Brackish water: A mixture of salt and fresh water.  It is not considered to be freshwater, but not as salty as seawater.

Why do we care about salinity?

• Salinity affects the organisms living in it.  Most marine organisms die in freshwater. 

• Even slight changes in salinity affect organisms in a harmful way.

• Some organisms have developed adaptations to live in various salinities or who live in both fresh and marine waters.

Poll

Without looking through the internet, how salty do you think that the ocean is on average???

• 3.5%

• 15%

• 28.5%

• 55%

• 86.2%

Tides

EQ: What causes tides?

What are tides?

Tides are the regular and predictable changes in sea level that correspond to the relative positions of the moon and sun.

Why do tides matter?

• Tides cause more or less beach to be exposed to the air.  

• It could be easier or harder for predators to dig and eats animals that are buried in the snad.

Poll

What causes tides?

• Currents

• Large ocean animals

• The moon

• Tides are not caused by anything

Tides are caused by the gravitational pull from the moon (2x) and the sun.

• Water bulges out due to gravity and then tides are created.

Spring Tides

• Pull of the sun and moon are in line

• Moon is in full or new moon phase

Neap Tides

• Pull of the sun and moon are perpendicular, at a 90 degree angle

• Half moon phase, either waxing or waning

Multiple Choice

Is this diagram depicting a spring tide or a neap tide?

• Spring tide

• Neap tide

Multiple Choice

Is this diagram depicting a spring tide or a neap tide?

• Spring tide

• Neap tide

Ocean Currents

EQ: What is a benefit of having all ocean currents on Earth being connected?  What is a potential negative?

Open Ended

What is something new that you learned from the video about the ocean's currents?

Currents 

• An ocean current is a continuous flow of water 

• Horizontal surface current: Caused by changes in wind and the Earth's rotation

• Deep ocean current: Caused by changes in the temperature, density, and more.

Horizontal Surface Currents

• Caused by prevailing winds and the Earth's rotation

• Northern hemisphere currents flow clockwise

• Southern hemisphere currents flow counter clockwise

• Gyres: The surface currents that rotate in circles and is caused by the Coriolis Force

Multiple Select

Which of the following cause horizontal ocean currents?

• Ocean upwelling

• Prevailing winds

• The Titanic wreckage

• Earth's rotation

• None of these

Vertical Currents 

• Water masses moving apart

• Water moving away from the land, upwelling

Open Ended

How could ocean upwelling be a positive thing?

Plankton Upwelling Zones

But what about Riptides?

Should really be called rip currents

Open Ended

What could one negative effect of having the ocean currents as a Great Conveyor Belt, with all currents attached to one another?

Sand

EQ: How could the type of sediment affect the organisms living there?

Benthic Substrates

• Sand, mud, rocks, rubble, and boulders

• Substrates are important because they provide foundation and are a product of the enviroment

• Sediments form substrates and are composed of eroded rocks.

Multiple Choice

Where do benthic substrates (sand) come from?

• Animals

• Eroded rock

• Hydrothermal vents

• Volcanos

Dissipative Beach

• High energy beaches, wide surf zone

• Low sloping, fine sand

• Wave dominated beach

Reflective Beach

• Low energy beaches

• Steep narrow beaches with course sand

• Narrow surf zone

• Relatively short in length because they form in pockets along the coast line

Multiple Choice

This is a beach that you go to to go surfing. There is a large surf zone and is high energy with lots of waves. What type of beach is it?

• Reflective

• Dissipative

Sand Grains

• Created by the erosion of mountains by wind and waves

• Centuries of rubbing together, the grains have become smooth, round, and small

Sand Types

Poll

Sand size says a lot about the environment that it is found in. Do you think that larger or smaller grains of sand are older?

• Larger

• Smaller

Sand Types

• Biogenic: Composed of living or once living components of the enviroment

• Abiogenic: Composed of the non-living components of the environment

Abiogenic Sand

• Basalt: Present around volcanic islands, like Hawaii

• May contain olivine (green) and glassy obsidian (black volcanic glass) sands
  
  

• Granite: Present in the crust of the United States.

• Mineral sands formed by the breakdown of granite usually contain quarts and feldspar.

Black sand beaches are typically mostly composed of obsidian

Biogenic Sand

• Most biogenic sands are composed of fragments of corals, algae, and mollusk shells

• Also can include sea urchin spines, sponge spicules, and fossil remains.

Open Ended

Biogenic sand is found on beaches that typically have coral reefs. Why might this be?

Ocean Zones/Pelagic Zones

EQ: Why is ocean depth important to marine organisms?

Intertidal Zone

• Along the shoreline, exposed to air at low tide

• Organisms must protect themselves from land and sea predators and prevent themselves from drying out

• Tidepools

Photic/Sunlight Zone

• Plenty of light and heat from the sun

• Photosynthesis is happening here in abundance 

• Minimal pressure

• Coral Reefs found here

• 0-200 meters deep

Multiple Choice

What percentage of animals are found in the photic zone?

• 50%

• 75%

• 90%

• 95%

Mesopelagic Zone/Twilight Zone

• Faint sunlight reaches here

•  Enough light to see during the day, not enough for photosynthesis

• Pressure increases

• 200-1000 meters down

Bathylpelagic Zone/Midnight Zone

• No visible light, only bioluminescence

• Not densely populated, but much larger than the twilight and photic zone

• 1000-4000 meters

Abyssal Zone/Abyss

• Greek word for no bottom

• Near freezing, no natural light

• Animals adapt to catch prey, bioluminescence 

• 75% of the ocean floor

Poll

What do marine organisms need to account for to live in the deep ocean?

• Lack of light

• Increase of pressure

• Minimal prey species

• Decrease in temperature

• Nothing all organisms can handle everything

Hadal Zone/The Trenches

• Deepest zone; down to the end of the trenches

• No light, near freezing

• Pressure is astounding

• Mariana Trench= deepest point on Earth

• Invertebrates can live here

Poll

Which ocean zone do you believe is the harshest environment for marine organisms to live in?

• Intertidal

• Photic

• Twilight

• Midnight

• Abyssal