Life in the Life in the OceanOcean

Chapter 13

Life, Energy, and FOOD!Life, Energy, and FOOD!All life needs energyEnergy is the ability to do workIdentify different forms of energy:Chemical, Mechanical, Electrical,

Nuclear, Thermal, Radiant, Sound, Potential, Kinetic, Gravitational

Life forms need energy to build complex systems from simple molecules.

Life forms manipulate energy to meet the organism’s needs

Laws of Thermodynamics related Laws of Thermodynamics related to Lifeto Life

2nd Law of Thermodynamics shows that over time systems tend to breakdown, become disorganized.◦Entropy is a measurement of this

breakdown process.What are some examples of entropy?

◦Aging rusting metals fading colorsA flow of energy decreases entropy!

The Sun’s ENERGY is keyThe Sun’s ENERGY is keyElectromagnetic Spectrum

Sun Empowering LifeSun Empowering LifeOrganisms with chlorophyll convert

photon energy into chemical potential energy (glucose).

These organisms are called producers

Photosynthesis Equation◦6CO2 + 6H2O → C6H12O6 + 6O2

Chemosynthesis alternative, anti-Sun!◦Is the production of usable energy directly

from energy-rich inorganic molecules

Primary ProductivityPrimary ProductivityPrimary productivity is the synthesis

of organic materials from inorganic substances by photosynthesis or chemosynthesis. (Units: gC/m2/yr)

Main organic material produced is glucose

Main source of carbon for glucose is dissolved CO2. (hmmm, climate change?)

90 -96% of oceanic carbohydrates are produced by phytoplankton.

Marine vs. Terrestrial Marine vs. Terrestrial ProductivityProductivity

Global net productivity of organic materials◦Marine ecosystems produce 35-50 billion

metric tons/year◦Terrestrial ecosystems produce 50-70

billion metric tons/yearYet, total producer biomass is 1 – 2

billion metric tons in the ocean to 600 – 1,000 billion metric tons on land

Which is more effective at producing organic materials?!

Terms so far2nd Law of ThermodynamicsEntropyChlorophyllPhotosynthesisChemosynthesisPrimary productivityBiomassPrimary producer

How do you feed?Autotrophs or primary producers

chemically generate their own food within themselves.

Heterotrophs rely on others for their food.

Primary consumers, herbivores, are animals that eat primary producers.

Secondary consumers eat the primary consumers, and so on…till we get to

Top consumer, top carnivore, or apex predator, typically nothing eats this organism

Basic Elements Needed to Basic Elements Needed to LiveLive23 of 119 elements common to

all life formsCarbon, hydrogen, oxygen, and

nitrogen make up 99% of the mass of all living organisms.

Carbohydrates, lipids, proteins, and nucleic acids are the main categories of chemicals found in life.

Elements in CyclesElements in CyclesBiogeochemical cycles support

and sustain living organisms with a large-scale transport between the chemical reserves and the organisms themselves.

Elements are always on the move through-out the environment.

Carbon CycleCarbon CycleLargest of all biogeochemical cyclesConsidered the basis for life because

it builds long chain molecules.Carbon moves through the marine

environment in these three ways:◦ Incorporated into plants and animals◦Respired by animals as CO2◦Excreted back into seawater as dissolved

carbon dioxide◦Ex. A typical marine plant, uses 45% of C

for growth, 45% for respiration, and 10% lost as DOC

Carbon Cycle IllustratedCarbon Cycle Illustrated

Nitrogen CycleNitrogen CycleNitrogen is needed for the formation of

proteins, chlorophyll, and nucleic acidsFound in the ocean as N2, dissolved organic nitrogen (DON), and as dissolved inorganic ions (nitrite, nitrate, and ammonium)

Most organisms cannot use free nitrogen in the air or ocean.

Bacteria and cyanobacteria are needed to fix the nitrogen with hydrogen and oxygen

Still Cycling NitrogenStill Cycling NitrogenAs plants assimilate the fixed nitrogen,

animals pass the nitrogen along through the food chain.

Eventually this nitrogen is excreted as ammonium and urea back into the environment.

Nitrifying bacteria breakdown ammonium and urea into nitrates

Denitrifying bacteria convert nitrates into nitrite and nitrogen gas, which is lost to the atmosphere

Nitrogen & Phosphorus Cycles

Physical FactorsPhysical FactorsA physical factor is any aspect of

the physical environment that affects living organisms.

The ocean provides a milder, less variable set of physical factors for marine life to flourish.

Marine physical factors include: light, temperature, dissolved light, temperature, dissolved nutrients, salinity, dissolved gases, nutrients, salinity, dissolved gases, acid-base balance, and hydrostatic acid-base balance, and hydrostatic pressurepressure

Biological FactorsBiological FactorsBiological factors are generated

by an organisms interaction with their environment. The following are examples:◦Food sources◦Reproductive needs◦Predator/prey relationships◦Instinctive behaviors◦Communication

Power of LightPower of LightLight penetrates the ocean at

different depths depending on the following:◦Number and type of suspended

particles◦Number of organisms with

chlorophyll which reflects green light◦Blue light penetrates deepest.◦Red light is absorbed near the

surface

Light ZonesLight ZonesPhotic zone is the uppermost layer of

seawater lit by the sun. This zone extends down100 meters near the coast to 590 meters in the tropical Pacific.◦Euphotic zone is the upper part of the

photic zone where photosynthesis occurs◦Disphotic zone is below the euphotic

zone where it is too dim for photosynthesis to occur.

Aphotic zone is the permanently dark layer of seawater beneath the photic zone. Most of the ocean never sees the light of day

Thinking CriticallyThinking CriticallyThe 2nd Law of Thermodynamics states

that entropy tends to increase with time. But living things tend to become more complex with time. How can this be?

Researchers believe there may be as many as 100 million species living on or in the Earth. If we know about a million or so species, where are the other 99 million?

Are you ready for what’s next?Are you ready for what’s next?Take out a sheet of paper…Take out a sheet of paper…

Quiz Ch. 13 worth 30 pointsAnswer the following:

1. How is entropy countered in nature?

2. Can there truly be an apex predator?◦Defend your response

3. Briefly explain how carbon moves through the environment.

Temperature BasicsTemperature BasicsThe average temperature of the

world ocean is a few degrees above freezing.

Heat is a form of energy produced by the random vibration of atoms or molecules.

Temperature is the measure of the atomic and molecular vibration in a substance, indicated in degrees.

Hot vs. Cold Hot vs. Cold An increase in temperature

increases the rate at which chemical reactions occur.

All living organisms have a metabolism.

Metabolic rate is the speed at which energy-releasing chemical reactions occur within an organism.

The metabolic rate roughly doubles with a 10°C increase in temperature.

In COLD Blood!In COLD Blood!A vast majority of marine life is cold

blooded or ectothermic.An organism that is ectothermic has

an internal temperature very close to the temperature of its surroundings.

Complex animals, such as mammals, birds, and some larger, faster fish, are warm blooded, or endothermic.

Endothermic animals have a high internal temperature.

Dissolved NutrientsDissolved NutrientsA nutrient is a compound required

for the production of organic matter.Main inorganic nutrients are nitrogen

and phosphorus.◦Nitrogen is usually found as nitrate NO3

and is used to build proteins, chlorophyll, and nucleic acids.

◦Phosphorus is usually found as phosphate PO4 and is used to build bone and tissues.

SalinitySalinitySalinity is a measure of the dissolved

solids in seawater.Salinity varies around the world, from a

low of 6‰ in the Baltic Sea to a high of 40‰ in the Red Sea.

A change in salinity affects the following:◦Physically damage cell membranes◦Alter protein structures◦specific gravity and density of seawater,

thus changing the buoyancy of an organism◦Water balance in cells

Dissolved GasesDissolved GasesOxygen does not dissolve readily in water.

There is about 100 times more oxygen in the atmosphere than in the ocean

Carbon dioxide is much more soluble and reactive in seawater. The ocean contains 60 times more CO2 than the atmosphere.

Physics note: Colder water contains more gas at saturation than warmer water.

Photosynthesis at the surface lowers the concentration of CO2 and increases the amount of dissolved O2.

pH ScalepH Scale •Seawater is slightly alkaline at pH of 8.•Dissolved substances in seawater act as buffer to pH changes

Hydrostatic PressureHydrostatic PressureHydrostatic pressure is the

weight of the water pressing down from above.

At high pressure gases become more soluble, some enzymes are inactivated, and metabolic rates for a given temperature tend to be higher.

Diffusion, Osmosis, and Diffusion, Osmosis, and Active TransportActive TransportDiffusion is the movement –

driven by heat-of molecules from a region of high concentration to a region of low concentration

Osmosis is the diffusion of water through a membrane.

Active transport is osmosis at the expense of energy

Classifications of the Marine Classifications of the Marine EnvironmentEnvironmentA zone is an area of

homogeneous featuresPelagic zone is the open water

divided into the neritic zone and oceanic zone.

Neritic zone is near shore over the continental shelf.

Oceanic zone is the deep water beyond the continental shelf.

Classifications of the Marine Classifications of the Marine EnvironmentEnvironment

Benthic zone is the actual bottom of the ocean.

Littoral zone is the intertidal area or band of coast alternately covered and uncovered by tidal action.

Bathyal zone covers the seabed on the continental slope.

Abyssal zone covers the ocean depth beyond the continental slope.

Hadal zone is the deepest seabed, found as trench walls and floors.

Theory of EvolutionTheory of Evolution

Evolution is the ability of living things to change through time to fit their physical and chemical environment, to become more efficient at extracting energy, to colonize locations capable of sustaining them.

Theory of Theory of EvolutionEvolutionNatural Selection is the process for how

living organisms might evolve with the passage of time.

More offspring are produced than can survive to a reproductive age

Random variations occur, some of these are passed along via genetics

Favorable traits are passed along, unfavorable traits tend to die out

Organisms with favorable traits are termed selected

The natural environment does the selection, the selected possess the favorable traits required to survive, unless the environment changes

Evolutionary ChangesEvolutionary ChangesMutations are an inheritable change in an

organism’s genes.Most mutations are unfavorable.Some mutations are favorable and

enhance the survivability of the organism.Natural selection takes a great deal of

time.Evolution by natural selection is the

accumulation of favorable structural or behavioral traits is known as adaptations.

A species is a group of interbreeding organisms that is reproductively isolated from all other forms of living things.

Theory of Intelligent Theory of Intelligent DesignDesignThe theory of intelligent design

is a combination of law, chance, and design—the activity of a mind or some form of intelligence that has the power to manipulate matter and energy.

Living systems look designed for a purpose.

Interactions between species provide evidence of intelligent design.

Systems of ClassificationSystems of ClassificationTaxonomy is the study of biological

classification.A natural system of classification

relies on an organism’s evolutionary history and developmental characteristics.

Carl Linnaeus, 1707 – 1778, was a Swedish naturalist that first began to organize the natural world. His system for naming, ranking, and classifying organisms is still in wide use today. He is considered the Father of Taxonomy

Kingdoms of LifeKingdoms of LifeMonera = bacteria, single chromosome,

asexual reproduction, extreme metabolic diversity, no nucleus.

Archaea = “super bacteria” extra capabilities due to extra genes, can live in extreme environments

Protista = usually unicellular, sexual or asexual, great genetic diversity

Fungi = usually multicellular, sexual or asexual, release enzymes to breakdown food

Plantae = multicellular photosynthetic autotrophs, sexual or asexual reproduction

Animalia = multicellular heterotrophs, sexual or asexual reproduction