AICE Marine Cheat Sheet! Yay!

Unit 2 Marine Ecosystems and Biodiversity

(a) Explain the meaning of the terms ecosystem, habitat, population, species, biodiversity, ecological niche.

Habitat The place an organism lives e.g. hydrothermal vent for tube worms.Ecosystem The living organisms and the non-living factors which influence them, e.g.

rocky shore. Population Organisms of the same species living in the same area, e.g. ghost crabs.Community All the species living in an area at the same time.Species A group of similar organisms that can interbreed and produce fertile

offspring, e.g. skipjack tunaBiodiversity The numbers of different species in an ecosystem.Ecological Niche The role of an organism in an ecosystem. Will cause competition if

similar niches overlap.

(b) Describe each of the following types of relationships within a marine ecosystem:

Relationship Definition ExamplesMutualism Affiliation

between species which each benefits.

Coral and ZooxanthelleCleaner fish and groupersChemosynthetic bacteria and tube worms

Parasitism Affiliation between two organisms that benefits one but hurts the other.

Tuna and NematodesEctoparasites are outside the body (fish lice)Endoparasites are inside the body (Nematodes)

(c) Explain the meaning of the terms producer, consumer, predator, prey and trophic level within the context of food chains and food webs.

Term Definition ExampleProducer Organisms that can

synthesize organic substances from simple organic compounds, using light energy from the sun or chemicals from the ocean.

Photosynthetic planktonChemosynthetic bacteria at hydrothermal vents

Consumer Organisms that obtain their energy by feeding on other

Herbivore and Carnivores

organisms.Predator An animal that catches, kills,

and consumes another animal.

SharksOctopusesKiller Whales

Prey An animal that is caught, killed and consumed by another.

SealsSea LionsAnchovies

Trophic Level The feeding levels’ in a food chain or food web.

First trophic level – producerSecond trophic level – whatever eats the producer and so on.

Chemosynthetic bacteria at hydrothermal vents are the producers of these environments and make organic substances by oxidizing hydrogen sulfide.

Trophic Level example:

Producerprimary consumersecondary consumer

First trophic levelsecond trophic levelthird trophic level

Arrows show the transfer of energy and biomass.

(d) Explain how populations of predator and prey may be interrelated.

If the availability of food increases so do the prey, thus increasing the predators; and the converse is true. See fig. 2.1 in review packet! See fig. 2.1 in review packet!

(e) Describe shoaling and explain why shoaling may be a successful strategy for feeding, reproduction, and predator avoidance, with reference to tuna and sardines.

A shoal consists of large numbers of fish of the same species and approximately the same size.

Advantages of Shoaling Explanation Increased Hydrodynamic Efficiency Saves energy to swim in a large group by

reducing drag.Predator Avoidance Large shoals may confuse predators.

Also more eyes are looking out for predators.Increased Foraging Efficiency Time to find food is decreased.Reproductive Advantage Increased chance of finding a mate within a

shoal as opposed to alone.

(f) Explain the meaning of the term succession and describe examples, including tube worms Tevnia and Riftia.

The term succession refers to the gradual process of change that occurs in an ecosystem over a period of time.

Succession of Hydrothermal Vents1. Bacteria grow near the vent.2. One of the first animals that arrives is the tube worm Tevnia.3. Eventually, Tevnia is replaced by the larger and faster growing Riftia.

(g) Understand why extreme and unstable environments tend to have relatively low biodiversity, giving examples including coral reefs (stable and not extreme), sand on a reef slope (unstable) and hydrothermal vents (extreme).

Stable Environment Coral Reefs. Have high biodiversity due to favorable conditions.

Unstable Environment

Sandy slope of coral reefs. Easily dries out and eroded away. Only animals that can burrow into the sand can survive this unstable environment. Low biodiversity due to changing conditions.

Extreme Environment

Hydrothermal vents. Extremely high temps and pressure restrict organisms that can live here. Low biodiversity due to the extreme conditions.

(h) Give examples of organisms that occupy specialized and generalized niches, including coral eating butterfly fish and tuna.

Organisms with specialized niches have a very narrow range of food requirements or live in a specific habitat. Most of the coral eating butterfly fish have specialized niches because they live in certain areas of the coral reef and feed only on a few species of coral and anemone.

Organisms with generalized niches have a wide range of food requirements and can exploit a wider range of food sources and habitats. Tuna have generalized niches because their environment is the open ocean and they feed on any number of fish species.

(i) Explain habitats with high biodiversity tend to contain narrow ecological niches.

Due to high biodiversity each species needs to have narrow ecological niches in order to lessen overlap and interspecific completion, so no species is out competed and becomes extinct.

Unit 3 Energetics of Marine Ecosystems

(a) Explain that photosynthesis captures the energy of sunlight and makes the energy available to the food chain.

Photosynthetic organisms capture light energy and use this to synthesize organic substances through photosynthesis. As consumers eat the plankton or plants that energy is passed on to them and then it continues up the food chain.

(b) Explain that chemosynthesis captures the chemical energy of dissolved minerals, and that chemosynthetic bacteria at hydrothermal vents make energy available to the food chain.

Chemosynthesis is the process of deriving energy from the oxidation of hydrogen sulphide and use this energy to produce organic compounds. These organic compounds are the basis of the food chain at hydrothermal vents. Also, the bacteria that carry out chemosynthesis have formed a mutualistic relationship with tube worms.

(c) Explain the meaning of the term productivity and how productivity may influence the food chain.

Productivity is the rate of production of biomass. Productivity is often measured in terms of energy per unit area per year. The productivity of an ecosystem affects all trophic levels.

(d) Calculate and explain the energy losses along food chains due to respiration and wastage.

Only a small percentage of the sunlight energy that reaches Earth is captured and used for photosynthesis. Much of it is reflected by surfaces, passes right through the producer, or lost to the inefficiencies of photosynthesis.

About 10% of energy available at each trophic level is transferred to the next trophic level. The other 90% is lost due to many factors: not all the organism is eaten, lost due to feces or death, but most is lost as heat from respiration. (See fig. 3.2 page 14 of review packet).

(e) Calculate and account for the efficiency of energy transfer between trophic levels.

See example given in review packet on page 14.

(f) Represent food chains as pyramids of energy, numbers, and biomass.

An ecological pyramid has producers at the bottom at the base, and then a series of horizontal bars representing higher trophic levels. In each case, the width of the bar is proportional to the numbers, biomass, or energy. See example in Fig. 3.3 on page 14.

Unit 4 Nutrient Cycles in Marine Environments

(a) Demonstrate an understanding that there is a reservoir of nutrients dissolved in the surface layer of the ocean.

Also have nitrates and phosphate ions dissolved in the surface layer.

(b) Explain the processes by which a reservoir of dissolved nutrients is replenished, including upwelling, runoff from land, and dissolving of atmospheric gases.

Process to Replenish Dissolved Nutrients ExplanationUpwelling The movement of water from deep water

in the ocean to the surface layer, bringing with it nutrients to primary producers. Produced by deflection of deep water currents and wind moving water away from shore.

Runoff Runoff water may leach nutrients from the soil to be delivered to the ocean via rivers.

Dissolving Atmospheric Gases Carbon dioxide and nitrogen reach the surface layer this way.

(c) Demonstrate an understanding that the reservoir of dissolved nutrient is depleted by uptake of organisms in food chains.

Primary producers remove some of these nutrients in order to complete photosynthesis.

(d) Explain how productivity may be limited by the availability of dissolved nutrients.

Productivity and the amount of dissolved nutrients are directly related, when nutrient levels go up so goes productivity.

(e) Demonstrate an understanding that nutrients taken up by organisms in food chains may sink to the sea floor in feces or after death, may be incorporated into coral reefs, or may be removed by harvesting.

How Dissolved Nutrients Are Removed From Surface Water

Explanation/Example

Uptake Dissolved nutrients are removed as producers utilize them to carry out photosynthesis.

Sink to the Sea Floor Dissolved nutrients may sink to the bottom via feces or dead bodies.

Incorporation Into Coral Reefs Coral reefs utilize calcium carbonate to produce their hard skeletons; thus removing this from the surface layer.

Harvesting Dissolved nutrients are removed via the harvesting of marine animals by humans for our own consumption.

(f) Show that each of the nutrient cycles listed below can be summarized buy the figure below and state the biological use of each nutrient.

Nutrient Biological Use(s)

Nitrogen Used in the synthesis of proteins.

Carbon Used to make all organic compounds, such as carbohydrates.

Magnesium Used to make chlorophyll.

Calcium Used to make bones, corals, and shells.

Phosphorous Used to make DNA and bones.

Unit 5 Coral Reefs and Lagoons

(a) Demonstrate an understanding of the Darwin-Dana-Daly theory of atoll formation, and the evidence supporting the theory.

1. An oceanic volcano emerges from the sea and forms an island.

2. A fringing reef forms around the island.

3. The island subsides and a barrier reef forms.

4. The island disappears under the water, leaving an atoll.

The evidence that supports this idea is deep drilling.

(b) Relate the Darwin-Dana-Daly theory to the physiology of coral.

Three Types of Reefs1. Fringing Reefs2. Barrier Reefs3. Atolls

Conditions Needed For Coral Growth

Temperature 16 - 35°C, with best being 23 - 25°C.

Clear Water Silt reduces light penetration.

Depth Within 20m of surface for light.

Attachment Need a suitable substrate to attach to, mostly basaltic rock.

(c) Discuss the role of reefs in dissipating the energy of waves, and in providing protection for shores and anchorages.

Benefits of Coral Reefs Absorb the energy of waves to protect from erosion. Protect coastal properties. Protect ecosystems. Reduce the cost of breakwaters. Provide safe anchorage. Have economic advantages.

(d) Discuss the factors that can lead to the transition from reef growth to reef erosion.

Factors that Lead to Reef Erosion Predation – such as the crown-of-thorns starfish. Storm Damage – can physically damage the corals. Exposure to Air – Can lead to desiccation – or drying out and death.

(e) Discuss the impact of reef erosion, and the use of artificial reefs, on the protection of shores and anchorages.

Reef erosion leads to shores and coastal property being more exposed to wave damage.

Artificial Reef Advantages

1. Act as submerged breakwater.

2. They dissipate wave energy.

3. Reduce coastal erosion.

4. Protect anchored boats.

5. Provide economic growth to area.

(f) Describe the methods used to reconstruct the history of reefs, including drilling, geomorphologic analysis and carbon dating.

Geomorphology refers to the study of landforms and the processes that shape them.

Techniques to Understand the History and Growth of Coral Reefs

Deep Drilling Provides cores of material which can

identify corals and estimate their growth.Corals produce “bands”, like tree rings, which can produce evidence for changes in coral growth.

Carbon Dating Can be used to find the age corals.The proportion of C14 to C12in am sample can be used to estimate the age of the coral up to 50,000 years old.

(g) Explain how these methods may be used to investigate the effect of sea level changes on coral reefs.

Fossil corals, found at depths of 1200m for example, are evidence of subsidence.Fossil coral are found above sea level, providing evidence of changes in sea level.

Unit 6 The Ocean Floor and the Coast

(a) Discuss the theory of plate tectonics and the evidence supporting it.

Alfred Wegner proposed the theory of continental drift and Pangea.

The Theory of Plate Tectonics States that the outer crust of the Earth, known as the lithosphere, consists

of a number of plates. These plates float on the asthenosphere. These plates move slowly in relation to each other. This movement produces three types of plate boundaries:

o Convergent .o Divergent .o Transform↑↓.

Evidence for Plate Tectonics

Fit of coastlines of South America and Africa. Fossil distribution. Paleomagnetism (Magnetic stripes of ocean floor). Glacial scarring. Coal in Antarctica.

(b) Relate tectonic processes to the production of ocean trenches, mid-ocean ridges, hydrothermal vents, abyssal plains, volcanoes, earthquakes and tsunamis.

Ocean Trenches Formed along convergent boundaries where subduction is occurring. These are long, narrow and the deepest part of the ocean floor.

Example, the Challenger Deep.

Mid-Ocean Ridges

Underwater mountain ranges. Formed by the upward movement and spreading out of magma, which cools

and solidifies as it emerges. Occurs at divergent boundaries. Responsible for seafloor spreading.

Hydrothermal Vents

Occur in the deep ocean, usually near mid-ocean ridges. Sea water seeps into cracks in the ocean floor and is released from the

magma.

Abyssal Plains

Flat areas of the ocean floor. Situated in between ocean trenches and continental rises. Formed by the upwards movement of molten material. Arises as uneven rock that is covered with fine grained sediments.

Volcanoes

Formed where there is an opening in the Earth’s crust. Allows hot gas and magma to escape from beneath the surface. Can form where there is thinning of crust at tectonic plate boundaries. Most volcanic activity is submarine. This forms new seafloor at divergent boundaries and gives rise to mid-ocean

ridges.

Earthquake

Occurs where there is a sudden release of energy in the Earth’s crust, creating seismic waves.

Can occur at convergent boundaries. Two plates are unable to slip past each other and may lock together,

creating tension. When this tension is released it generates an earthquake.

Tsunamis

A long wavelength wave produced by the sudden movement of a large volume of water.

Can occur at a convergent boundary.

In deep water the wave travels fast, but as it approaches the coast it slows down but forms a huge, destructive wave.

(c) Explain why the water coming from hydrothermal vents is under pressure, hot and rich in minerals.

Cold water seeps into crack or fissures in the ocean floor.This water is heated by magma and it forces the water back up to the ocean floor.It carries with it minerals dissolved in the magma with it.A hydrothermal vent if formed when the minerals precipitate out of the water.Due to its depth, the pressure at a hydrothermal vent the water may be superheated and reach temps higher than 100°.

(d) Explain how isostasy may produce shallow seas within or at the edge of continents.

The principle of isostasy shows that the Earth’s crust is generally higher where it is thicker and less dense; lower where it is thinner and denser.The density of continental crust is less than that of oceanic crust.

(e) Demonstrate an understanding of the processes of erosion and sedimentation that gives rise to the morphology of the littoral zone, including rocky shores, sandy shores, muddy shores, estuaries and deltas.

The littoral zone can be defined as the area of a coast between the high water mark and the lowest part of the shore that is permanently under water.

Rocky Shores Characterized by outcrops of rock which are exposed to erosion by the sea. Resistant to weathering and break down less than softer rock areas. Rocky shores are the most exposed type of shore and the most resistant to

erosion.

Sandy Shores

Formed by the erosion of sandstone and the deposition of sand.

Muddy Shores

The least exposed to erosion. Can create “mud flats”.

Estuary

A semi-enclosed coastal body of water, which has a connection to the sea. Produces brackish water, a mix of salt and fresh water.

Deltas

Formed when a river carrying sediments reaches a large body of water. As the river increases in width, the flow rate slows and the sediments

settle. Form triangular formations, thus the name delta.

(f) Demonstrate an understanding of how environmental factors influence the formation of ecological communities in the littoral zone, including mangrove, sandy shore and rocky shore.

Mangroves

Tree that grow in tropical and subtropical saline habitats. Usually between 25°N and 25°S latitudes. Have special roots, called pneumatophores, which obtain oxygen directly

from air. Advantages of Mangroves

o Trap particles suspended in water.o Reduce water flow.o Increase sediment deposition.o Provide habitats.o Dissipate wave energy.

Sandy Shores

Unstable environments. Easily eroded away by wind and water. Does not have high biodiversity. Only burrowing animals are associated with sandy shores.

Rocky Shores

High biodiversity. Stable environment. Clear zonation of species. Animals here must be able to resist desiccation (drying out). Environmental Factors of Rocky Shores

o Desiccationo Temperatureo Wave actiono Light intensity

o Aspecto Slopeo Substrate

Unit 7 Physical and Chemical Oceanography

(a) Demonstrate an understanding of the effects of volcanic activity, runoff and atmospheric dissolution on the chemical composition of the ocean.

Seawater has a salinity of 35‰.

Seawater can be diluted by precipitation, freshwater from rivers, or melting glaciers.

The chemical composition of the ocean stays pretty constant.

Local changes to this composition can come about via:

Volcanic activity Runoff Atmospheric Dissolution

Volcanic Activity

Submerged volcanoes release gases, including chlorine.

Runoff

The flow of water from land, arising from rain or melting snow and ice. Most of this drains in to the ocean. Remember Mina Mata Bay.

Atmospheric Dissolution

Gases dissolved in seawater are in equilibrium with the atmosphere. Concentration of gases depends on the gas’s relative solubility, the temperature and

salinity of water. Gases in seawater consist mainly of nitrogen, oxygen, and carbon dioxide.

(b) Outline the effects of evaporation and precipitation on salinity.

Salinity is the measure of the saltines, or salt concentration, of water.Expressed as parts per thousand (‰).

Average salinity of the ocean is 35‰.Evaporation of water increases salinity.Precipitation, influx of freshwater from rivers, and melting glaciers decrease salinity.

(c) Describe how temperature and salinity gradients form in water columns to produce ocean layers (including the surface layer, thermocline and deep ocean), and how subsequent mixing of these layers may occur.Temperature

As temperature increases, the density of water decreases. Warm water forms a layer on top of colder, denser water. This results in a decrease of temperature as depth increases. The interface between these two layers, where the temperature decreases rapidly as

depth increases is called the thermocline.

Salinity

As salinity increases, density increases. Lower salinity water floats on top of higher salinity water. This results in a gradual increase in salinity as depth increases, with a region referred to

as halocline where there is a significant change in salinity as the depth increases.

Wind blowing across the surface of the water or a decrease in the temperature of the surface layer can cause mixing of the layers.

(d) Demonstrate an understanding of the physical and biological reasons for the variability of the concentration of dissolved oxygen.

Physical Reasons for the Variability Of dissolved Oxygen Turbulence. Mixing by waves.

Biological Reasons for Variability of Dissolved Oxygen

Photosynthesis of algaeincreases dissolved oxygen. Respiration of marine animalsdecreases dissolved oxygen.

Dissolved oxygen concentration changes with depth:

High at the surface. Drops to the oxygen minimum layer, at about 100m – 1000m. Then increases again as depth increases.

(e) Describe how tides are produced, and how the alignment of the Moon and Sun, coastal geomorphology, wind, air pressure and size of water body affect tidal range.

Tides are the regular rise and fall of sea level.Due to the gravitational effects of the Sun, Moon, and the rotation of the Earth.Most coastal areas have two high tides and two low tides per day.Spring Tides

When the Sun. Moon and Earth are lined up. Occurs at the new Moon and the full Moon. Tidal amplitude is highest during these. (have the highest high tides and the lowest low

tides)

Neap Tides

When the Sun, Moon and the Earth are at right angles. Occurs at the first quarter and third quarter moons. These are when tidal amplitude is the lowest.

Tidal range is the difference in height between low water and high water.

What Affects Tidal Range (Tidal Amplitude)

Shape of the coastline. Slope of the coast. Size of body of water. Weather conditions. Changes in air pressure and winds.

(f) Explain how wind, temperature, density, the Coriolis Effect and the shape of the sea bed produce ocean currents and upwelling.

Ocean currents are the continuous movement of water, driven by: Waves Winds The Coriolis Effect Temperature Salinity Tides

Surface ocean current typically are driven by winds and have a spiral to them due to the Coriolis Effect.

Deep ocean currents are driven by temperature and density gradients.

Upwelling areas are areas where significant vertical movement of water occurs.

Can be caused by mid-ocean ridges or winds off shore.

(g) Discuss the causes and effects of El Nino events in the Pacific Ocean.

El Nino Occurs in the southern Pacific Ocean. Normal Conditions

o Cold water, rich in nutrients, flows in a northerly direction along the west coast of South America.

o This is accompanied by an upwelling of nutrients, caused by winds blowing from the south.

o Results in the water have high productivity, with large #s of anchovies and sardines feeding in the plankton rich water.

o These fish support a large fishing industry.

El Nino Conditions o The prevailing winds stop blowing normally.o Warm-equatorial water is blown by abnormal winds from the west.o Pressure gradients in the west and east Pacific are reversed, causing a reversal

of winds direction and equatorial currents.o This creates a large area of warm water, upwelling stops and so the supply of

nutrients to the surface water is reduced.o The increase in temperature results in the death of many cold water species and

with the lack of nutrients due to no upwelling occurring it is disastrous to the fishing industry.

A major El Nino event occurred in 1982-1983.

(h) Explain the seasonal differences in temperature between the Asian continent and the Indian Ocean, and explain how these differences give rise to the patterns of monsoon winds.

A monsoon is a seasonal wind of the Indian Ocean.In the winter months, the sea is warmer than the land and air over the sea rises and draws in the cooler air from land.During the summer monsoon this pattern is reversed: the air over the land is warmer and draws in the moist, cooler air from the ocean.These summer monsoons bring thunderstorms and heavy rain, as much as 80% of India’s total yearly rainfall.

(i) Discuss the factors required for a region of low pressure to develop into a tropical cyclone, and explain the role of evaporation, condensation and latent heat in tropical cyclones.

A tropical cyclone is a storm system, with a large low-pressure center and many thunderstorms with strong winds and heavy rain.Conditions Needed For Development

Develop over warm water of at least 26.5°C. Low pressure area Evaporation of water occurring.

As water vapor rises it condenses and releases tremendous amounts of heat (latent heat of condensation).This heat energy increases evaporation and this drives the development of the cyclone.It spins due to the Coriolis Effect.

(j) Recall that tropical cyclones are known as hurricanes and typhoons and discuss their impact on coastal communities.

Tropical Cyclone Names

Hurricane in North-Atlantic Ocean Typhoon in the north-west Pacific Ocean. Willy-Willy’s in Australia.

Destructive Forces of Hurricanes

High winds causes damage to coastal properties, causes waves that cause erosion, and can damage moored boats.

Heavy Rainfallcauses flooding, damage to coastal communities, and death from drowning.

Storm Surgesfloods low-lying coastal areas.

Pros to Tropical Cyclones

Heavy rainfall can benefit arid areas. Storm surges can replenish nutrient in coastal waters and increase productivity.