Download Marine Biology - Chaparral Star Academy

1 Sounding the Deep
Notes for Marine Biology:
Function, Biodiversity, Ecology
By Jeffrey S. Levinton
Marine Biology-components
• Functional Biology - How an organism
carries out basic functions, e.g.,
reproduction
• Ecology - Factors involved in distribution
and abundance of organisms
• Biodiversity - Controls on the number of
species
Historical Background
• Aristotle (384-327 B.C.) and peers - Birth
of natural history observation
• Linnaeus (1707-1778) - First systematic
classification, identification of species
• Georges Cuvier (1769 -1832) - Generalized
classification of animals
Historical background
• 19th century - Important time for
development of marine biology
• Edward Forbes (1815-1854) - Beacon sailed
on Mediterranean, developed Azoic theory
(no life deeper than 300 f = 1800 feet), first
marine scientific hypothesis!
• Michael Sars, 1850, disproved the Azoic
theory
Historical background
• Charles Darwin (1809-1881) - Voyage of
the Beagle, circumnavigated world, theory
of coral reef subsidence (drilling in
Enewetak partially confirmed hypothesis),
barnacle classification
• W.B. Carpenter and C. Wyville Thomson Started large oceanogr. Cruises, Lightning,
also falsified the Azoic theory
Historic Background 4
• H.M.S. Challenger (1872-1876), led by
Wyville Thomson and John Murray, all seas
but Arctic [F]
• Challenger - tested Haeckel’s Bathybius
theory (primordial slime), disproven
• Other late 19th century voyages, including
ones by Prince Albert I of Monaco, who
founded Oceanographic Institute, later led
by Jacques Cousteau
Historical Background 5
• 20th century - Founding of Scripps Inst. Of
Oceanography (1903), Woods Hole
Oceanographic Inst. (1930) - led to
American superiority in ocean science
• Late 19th century to 20th century: Founding
of numerous marine stations (e.g., Naples,
Friday Harbor Labs, Washington);
Historical Background 6
• 20th century - advances in technology,
especially in vessels
• Deep-diving submarines, remotely operated
vehicles (ROVs)
• Navigation and deep-water sampling
• SCUBA diving
• Ocean observatories, permanent stations
connected to shore with optical cable
Knorr, Research ship of Woods Hole Oceanographic
Institution
Alvin, deep-diving submersible, ported in Woods Hole, MA
Ventana, an ROV used by the Monterey Bay Aquarium
Research Institute
Ocean Observatory scheme for Monterey Bay
Hypothesis Testing
• Science involves devising questions that are
later explored by tests of hypotheses
• What are hypotheses? Statements that are
subject to testing.
• What is a test? This is a difficult subject.
But if you state a hypothesis and its
prediction turns out to be wrong, the
hypothesis is falsified.
Hypothesis Testing
• A hypothesis is a statement that can be
tested:
• Which of the following are testable:
• Temperature increases the rate of oxygen
consumption of crabs.
• Mermaids can never be observed but they
exist.
Hypothesis Testing
• What is a test? Experiments preferred but
distributional tests may be the only way to
study certain things.
• Experiment or distribution?
• 1. Crabs fail to see in the red end of the
visible spectrum
• 2. Diversity declines near a power plant
Null Hypothesis and Field Experiments
• Null hypothesis: There is no difference in
predation rate on the lower and upper shore
Objective of Experiment: Is predation more
intense on the lower shore, where we
believe predators are more common, than
on the upper shore?
Vertical rock face on a rocky shore of British
Columbia, Canada. Note seastars below mussels
Rocky shore predators
FIELD EXPERIMENT ON PREDATION
HIGH
Uncaged
Fully caged
Top-only cage
Side-only cage
LOW Uncaged
Fully caged
Top-only cage
Side-only cage
Caging experiment, showing fully caged experimental condition,
with three types of controls - BARNACLE OR MUSSEL LARVAE
CAN ENTER CAGES, PREDATORS CANNOT GET IN FROM SIDE
Place on upper shore and lower shore
= high density
= low barnacle
or mussel density
HIGH
Uncaged
Fully caged
Top-only cage
Side-only cage
LOW Uncaged
Fully caged
Top-only cage
Side-only cage
Caging experiment, showing fully caged experimental condition,
with three types of controls
Place on upper shore and lower shore
= high density
= low barnacle density
HIGH
Uncaged
Fully caged
Top-only cage
Side-only cage
LOW Uncaged
Fully caged
Top-only cage
Side-only cage
Starfish got into uncaged and top-only treatment
Life Habits of Marine Organisms
Depth-Habitat Terms
Intertidal vs. Subtidal
Continental shelf = Neritic vs. Oceanic = Pelagic
Epipelagic = Pelagic environments, 0-200 m depth
Mesopelagic = 200 - 1000 m depth
Bathyal = 1000 - 4000 m depth
Abyssal = 4000 - 6000 m depth
Hadal = trenches = > 6000 m depth
The End