chapter 14 · oceanography marine biology unit sections trophic levels and oceanic food webs...

Chapter 14

Oceanography Marine Biology Unit Sections

Trophic levels and Oceanic Food Webs

relationships

Oceanic Zones

Based upon light

Upon depth

Plankton

Size and niche

Benthos

Nekton

TROPHIC LEVELS Trophic levels are where an organism is on the food

chain (or food web)

Producers are Autotrophs that produce chemical food from Sunlight - on land these are plants

But tuna eat more than just one food and so do sharks

Sometimes the tables are turned

Food webs show all of the interconnectedness of organisms

Kelp forests are algae but don’t produce as much as Phytoplankton

Phytoplankton – Feed the Oceans and produce ½ of the world’s O2 PRODUCERS

Phytoplankton are eaten by Zooplankton (small animals)

Primary Consumers

Secondary Herbivores – Filter feeders

There’s plenty of food in phytoplankton for even big fish

And even really big mammals

Pyramids - Food, Biomass and /or Energy - every step gets 10% of the step before.

Producers Primary Consumers 1 °

Secondary Consumers 2 °

Tertiary Consumer 3 °

Quaternary Consumer 4 °

5 ° Consumer

What trophic level are we eating in the oceans?

Compare that to how we eat on Land

Producers and Primary Consumers

When was the last time that you ate a mountain lion?

This is Not Sustainable

Ecological relationships Parasitism Commensalism Mutualism

Parasitism – the host loses (sometimes dies) and the guest benefits.

Commensalism – The host gets nothing and the guest benefits

Mutualism – Both the host and Guest benefit (mutually)

Pelagic Zone- water environment

Neritic zone- pelagic zone above the continental shelf

Photic Zone 200m

Aphotic Zone Below 200 m (600 ft)

Oceanic zone- deep water away from the influence of land, further divided

into the photic and aphotic zone (without sunlight)

Benthic Zone- Seafloor environment (subdivided by depth) Intertidal Zone- between high and low tide

Subtidal Zone- below low water

Tropical Coral Reef Biome Abiotic Factors

Temperatures

Rainfall

Soil description

Biotic Factors Dominant Plants

Dominant Wildlife

Geographic Distribution

Mangrove Forest Biome Abiotic Factors

Temperatures

Rainfall

Soil description

Biotic Factors Dominant Plants

Dominant Wildlife

Geographic Distribution

Salt Marsh Biome Abiotic Factors

Temperatures

Rainfall

Soil description

Biotic Factors Dominant Plants

Dominant Wildlife

Geographic Distribution

Levels of Organization Species

Populations

Communities

Ecosystem

Biome – a group of ecosystems that have the same climate and similar dominant communities.

Ecological Methods 1 1. Observing what lives here?

2. Experimenting to test a hypothesis about the ecosystem.

3. Modeling long term phenomena with mathematical formulas to understand how it works.

Energy Flow - Sunlight is the main source of energy Producers- organisms that make their own food, also

known as autotrophs.

Include Plants, algae and some bacteria

Consumers – organisms that rely (eat) other organisms for their energy, also known as heterotrophs.

Include fungi and animals (you).

Food Chain The energy stored by producers can be passed through

an ecosystem along a food chain.

It is a series of steps in which organisms transfer energy by being eaten.

Each step is a TROPHIC LEVEL

Food Web The network of complex

interactions among all of the organisms in an area.

The connections form a web instead of a chain

Ecological Pyramids An ecological pyramid shows the relative amount of:

Numbers of individuals

Biomass of organisms

Amount of energy

In each trophic level

It decreases by 90% each step.

Cycles of Matter Biogeochemical Cycles

Matter (water, carbon, oxygen, etc) is recycled

Carbon Cycle CO2 in the atmosphere is taken up by plants and

turned into sugar.

The sugar is consumed by heterotrophs and turned back into CO2

Some plant matter gets buried and becomes fossil fuels

When this is burned, it goes back into the atmosphere (global warming)

Nitrogen Cycle N2 gas in the air (78 %) is not usable by plants or

animals

It is turned into fertilizer by lightening and nitrogen fixing bacteria

Plants turn it into proteins

Heterotrophs use the proteins and turn them into ammonia NH3

Plankton - Plankton are microscopic organisms that drift on the oceans' currents. They include organisms such as diatoms, dinoflagellates, krill, and copepods.

Phytoplankton Photosynthesize Zooplankton are little animals

Bacterioplankton - Bacterioplankton are the recyclers of the planktonic world. They are free-floating bacteria that break-down and recycle waste

material in the seas.

Microplankton (20-200 µm)

A region including the bottom of the sea

Animals and plants living on or within the substrate of a water body.

Benthic Organisms include: Burrowers Creepers Sessile organisms And some Swimmers

Mantis Shrimp

Creepers – worms, crustaceans

Benthic Swimmers

Benthic Sessile (don’t move)

Nekton – Organisms that can swim against currents. Cephalopods

Fish

Marine mammals

Reptiles