Marine Biology Exam 1

What is Marine Biology?

Study of organisms that live in the sea, including all water that has some degree of salinity, like the estuaries at river mouths

What is marine biology’s interdisciplinarians?

• Geology

• Chemistry (organic and inorganic)

• Physics

• Meteorology

• Zoology

• Botany

Marine biologist:

Study organisms that inhabit the sea

Oceanographers:

Study physical aspects of the ocean

4 branches of oceanography

• Biological oceanography

• Physical oceanography

• Geological oceanography

• Chemical oceanography

Is marine biology and oceanography the same?

No, they both have a different perspective of the marine world

Humans have been using the sea since _____ _____

early times

~ 165,000 yr old clam shells

discovered in a cave in south Africa

110,000 yr old shells

Harpoons and fishhooks

Pacific Islanders, Phoenicians

Sailed adjacent seas

Ancient Greeks

Knowledge of Med. Sea

Aristotle

Described many marine forms

Captain James Cook (1768-1780)

First Europeans to view Antarctic ice fields, + extensive mapping, and brought back many specimens

Wilkes Expedition (1832-1842)

• 10,000 specimens (2,000 unknown)

• Confirmed Antarctica as continent

Edward Forbes

• Studied seafloor around the British Isles

• Discovered that species on the sea floor vary greatly dependent on depth = fundamental principle of marine biology

Challenger Expedition (1872-1876)

• First major exploration devoted to the study of marine organisms

• discovered ~ 4,700 new species

• Published 50 volumes from data, took 19 years

Modern Marine Biology

Many marine biology research stations exist in locations around the world. Several facilities in the US:

• Woods Hole Oceanographic Institution and Marine Biological Laboratory, Massachusetts

• Scripps Institution -La Jolla, California

• Friday Harbor Laboratories, Washington state

• Monterey Bay Aquarium Research Institute

• Harbor Branch Oceanographic Institute

Remote sensing (tools in marine biology)

Using satellite technology to look at elevation, bathymetry, and ocean currents. Tells us a lot about the oceans and where they organisms are, and where life is distributed. They can follow large animals through _____ ______

Sonar (tools in marine biology)

Sound navigation and ranging. Was developed for sub warfare, but now it’s used to find animals, to figure out depth, and to fine seamounts

SCUBA (tools in marine biology)

Self-contained underwater breathing apparatus. Was developed in the late 1940’s for automobiles to run on compressed gas. Jacqu laristo modified it for underwater breathing

ROVs, AUVs, DSVs (tools in marine biology)

• Remote operated vehicles

• Autonomous underwater vehicles

• Deep submergence vehicles

Research vessels

Vehicles made into science vessels. Boats made for research

Marine Biology is…

• Survey class

• Reef life'

• Looks at small Benthic organisms, communities

• Medicine, food, fishing, the harm, the value

• Value = ~ $20 trillion per year

Dominant feature on the Earth

Ocean; 71%

61% of N Hemisphere

80% of S Hemisphere

4 Basins:

• Pacific

• Atlantic

• Indian

• Artic

Pacific

Deepest, largest, and the oldest

Atlantic

Younger, second in size

Indian

Similar to size to Atlantic, a little deeper

Artic

Smallest and shallowest

Deepest place in the Pacific

Marianas Trench

Deepest place in the Atlantic

Puerto Rico Trench

Deepest place in the Indian

Java Trench

Deepest place in the Artic

Molloy Deep

7 Seas/Oceans

• N, S Pacific

• N, S Atlantic

• Indian

• Artic

• Southern (surrounds Antarctica)

Bacon (1620)

Puzzel pieces? (Structure of Basins)

Alfred Wegner

• Continental Drift, 1912

• A single supercontinent, Pangaea

• Pangaea began breaking up 180 Mya

• Not widely accepted at the time

Plate Tectonics

1950’s

Divergent Boundary -Sea Floor Creation

• New from sea-floor spreading

• Spreading = 2-18 cm per year, varies

• Results in rifts and ridges

• Normal fault

• Nazca plate is one of the fastest - 5 to 18 cm per year

• Mid-Atlantic plate is 2-5 cm per year

Mid-Oceanic Ridges

= Chain of submarine volcanic mountains

• Sediment accumulates = floors are thicker

• away from the ridges = older

• Ridges is displaced by faults in crust = trans form faults

Convergent Boundary - Subduction zones

Trenches = deep depressions

• Marianna: 10,994 m

• Earthquakes, volcanoes - higher activity in area (“Ring of Fire”)

• Island Arcs = chains of islands in the ocean (e.g. W. Pacific)

• Side of deep-sea tranches

• Earthquakes and volcanoes all occur in ________ zones

• Reverse fault

Shear (Transform) Boundary

• 2 plates move and slip, creating friction

• Earthquakes common (i.e. San Andreas Fault)

• Strike-slip fault or transform fault

Lithogenous sediment

= derived from break-down of rocks (weathering)

• Red clay

Biogenous sediments

= derived from the skeletons and shells of marine organisms

• aged by carbon dating

• ocean temperatures

• Depth - CCD CaCO3

• Calcareous / siliceous ooze

• CCD = Calcium compensation Depth

Continental margins: boundaries between

Continental crust and oceanic crust consist of:

• Continental shelf (most landward)

• Continental slope

• Continental rise (most seaward)

Continental Shelf (most seaward)

• ~ 8% of ocean surface area, past exposure

• Richest area of the ocean (biodiversity)

• Width: 1 km - 750 km

• Shelf break depth: 120-400 m (average 200 m)

• International boundary

Continental Slope

• “Edge” of a continent; shelf break to C. rise

• Steepest part of continental margin

Continental Rise (most seaward)

• Formed by sediment pushed down from the continental shelf and slope

• “Underwater river delta” - deep sea fan

Active Margins

• More intense: earthquakes, volcanoes, and trenches

• Steep, rocky shorelines, narrow continental shelves, and steep continental slopes

• Ex. West Coast

Passive margins

• Relatively inactive

• Flat, wide coastal plains, wide continental shelves, and gradually sloping continental slopes

• Ex. East Coast

• Thick C. Rise

Oceanic crust

= Sea Floor / Abyssal Plain

• Seamounts, guyots, hills

• Mid-oceanic ridge, trenches, channels

• Hydrothermal vents

• - “Black” Smokers

Continental Shelf (zones)

Epipelagic Zone (the sunlight zone) 200m

Mesopelagic Zone (the twilight zone) 1000m

Continental slope (zones)

Bathypelagic zone (the midnight zone) 4000m

Continental Rise (zones)

Abyssopelagic Zone (the Abyss) 6000 m

Hadal zone

Hadalpelagic - the trenches. over 6000 m

Zones

Euphotic

0-200 m

Dysphotic

200-1000 m

Photosynthesis

to 80 m

Igneous and metasediment rocks form -

Continental crust

2-6 km carbonate (limestone, dolomite) -

and evaporate sedimentary rock succession punctured by dissolution

1-150 m veneer -

Of mostly siliciclastic sands soil horizon

Florida formation

• Opening up of Tethys ocean - global tropical ocean

• Rifting stops in Georgia - Georgia channel seaway

• Yucatan and Florida plates move away - forms Golf

• Collisions, Bahamas and Florida plates become inactive - Fl straits separate platforms

Florida plates today

Earthquakes? No

FL faults = inactive; Cuba and PR = active

Resultant makeup

• Karst - mostly north and central Florida - acidic water dissolving carbonate

• Causes:

• - Fracturing of rocks

• - Too much / too little water

• - Development

Silica invasion

• Eroding mountains

Deposition of carbonate

• In keys and everglades in Pleistocene and holocene

Resultant Sands around Florida

• White, squeaky

• Red streaks

• Brown/tan

• White, carbonate

Rocks

• Palm Beach County

• - Coquina - shell rich

• Florida Keys

• - Key Largo Limestone: reef rock (upper keys)

• - Miami Limestone: Oolitic grainstone (lower keys + Miami and Boward)

• - Caliche: lithified soils (paleosols); red from Saharan dust

Wetlands

• Critically impt, mostly protected

• Flat topography, low elevation, high water table, humidity

Everglades

• Low relief, gentle slope

• Laterally confined by E/W elevation (old lake/sea)

• Formed 125 kya, after last glacial period

• Holocene sediments: 4 m of mangrove peat; or 1 m of calcite mud; or exposed

• Largely impacted by humans

Coastlines

• Longests in US, 1305mi (2170km)

• Variable; wide range of geomorphology

• - 33% is not sand

Mainland

• Open, bay, inside lagoon

Barrier Islands

• Most formed in past 1000’s yrs

• Largest coastline category

• Vulnerable to erosion, flooding, migration - open

• Developed / seawalls = required nourishment

Plant Dominated

• Big Bend - marsh

• Ten thousand Islands - Mangrove

Coral Reefs

• 3rd largest in world

• Perched on older reefs

• Spur / groove

• Human impacted

• Limited nutrients - favorable