The Ocean

Biotic Factors: living factors in an ecosystem


  • Sea turtles
  • Sharks
  • Fish
  • Whales
  • Dolphins
  • Jellyfish


  • Coral
  • Sea anemone
  • Seaweed
  • Kelp
  • Sea grass
  • Algae

Abiotic Factors: non-living factors in an ecosystems

  • Salt Water
  • Water temperatures
  • Sunlight
  • Water currents
  • Rocks

Carrying Capacity: the largest number of individuals of one species that an environment can support

Resources needed: food, water, shelter, and space.

A population in my ecosystem changes over time depending on the availability of the needed resources. If there is a large amount of resources, a population will survive and slowly grow larger. If there is a limited supply of resources, a population will slowly decline.

For example, if small fish were to decrease in population, so would the population of whales, large fish, squid, etc. The populations would decrease because of the lack of food.

Limiting Factors: any factor or condition that limit the growth of a population.

Limiting Factors: water temperature, food, sunlight, pressure, and oxygen concentration.

Sharks prey on sea lions. If the shark population were to suddenly increase in a certain area the sea lion population would dramatically decrease and the sharks in that area would have to prey on something else if there is anything else.

Energy Roles: determined by how the organism gains energy within the ecosystem

Producer - organisms that make their own food by photosynthesis. They get their energy from the sun (ex. phytoplankton)

Consumer - organisms that cannot make their own food; they feed on other organisms for energy

  • Herbivores - get their energy from plants only (ex. whales)
  • Carnivores - get their energy from other animals (ex. sea otters)
  • Omnivores - get their energy from both plants and animals (ex. parrotfish)
  • Scavengers -  get their energy from dead organisms (ex. crabs)

Decomposer - Organisms that break down wastes and dead organisms and return the nutrients to the environment. They get their energy from those dead organisms (ex. bacteria)

Producers are vital to any ecosystem because they are the start of a chain. They receive their energy from the sun which is taken by a consumer.

Organisms basically get their energy from organisms in the consumer level beneath them. Plants get their energy from the sun.

Food webs/chains

Food webs are more realistic for ecosystems than food chains because they display more diversity in a predator/prey relationship among different organisms.

If the shark population were to be removed from the ecosystem, the amount of large fish would increase, thus reducing the small fish population and consequently will reduce the octopus population as it has less organisms to prey on.

Trophic Levels and Energy Pyramids

Third Level - (tertiary consumers; carnivores or omnivores; top predators) 1 kcal

  • Whale
  • Shark
  • Squid
  • Octopus
  • Jellyfish
  • Fishing birds and Shore birds

Second Level - (secondary level consumers; carnivores or omnivores) 10 kcal

  • Large fish
  • Small fish
  • Dolphins
  • Turtles

First Level - (primary consumers; herbivores or omnivores) 100 kcal

  • Krill
  • Coral
  • Shellfish
  • Shrimp
  • Jellyfish

Producer Level - (autotroph; plants) 1,000 kcal

  • Plankton
  • Phytoplankton

An energy pyramid is in the shape of a pyramid because it shows how the available energy decreases as it is used by the organisms in that level. An energy pyramid is wide at the bottom and small at the top to show how much energy is lost at each level.


CO2 + H2O (in the presence of sunlight) = C6H12O6 and O2

Photosynthesis needs three things in order to take place:

  • Sunlight or radiant energy
  • Carbon dioxide (CO2)
  • Water (H2O)

When a plant photosynthesizes, it produces two things:

Glucose (C6H12O6)

Oxygen (O2)

Photosynthesis takes place within the chloroplast of the plant.

Energy transformation: light energy -> chemical energy

Tropisms: the turning or bending movement of an organism toward or away from an external stimulus such as light, heat, or gravity


  • Coral growing upright
  • Most marine plants grow near the surface of saltwater within reach of sunlight

These tropisms allow marine plant life to gather sunlight for photosynthesis.


Decomposers are vital to my ecosystem because decomposers return nutrients from dead organisms back into the food web for producers to make energy with. If a producer does not have nutrients, it cannot create energy and consumers will not be able to absorb anything and survive. Producers would die and consequently other consumers will too.


  • Bacteria
  • Fungi
  • Marine worms
  • Sea slugs
  • Sea worms
Squat lobsters strip pig bones


Adaptations are important because they help animals survive by giving them the ability to eat certain foods and to hunt certain animals or to basically move around in their environment in a way that benefits them the most. For example, fish have gills that allow them to breathe underwater. This is a physical adaptation. A behavioral adaptation would be cuttlefish migrating to their birthplace to mate and reproduce.

Plant and animal adaptations

  • Gills
  • Most plants and algae grow on rocks so they won't wash away
  • Seaweed is tough and leathery so they won't be torn
  • Fins
  • Camouflage
  • Blubber
  • Ability to attract prey

If a shark were to be placed into a different environment such as a rainforest it would not be able to survive. It is adapted to breathe underwater so being on land, it would not be able to breathe and with its fins it will not be able to move. Obviously if an animal cannot breathe it can't live but besides that, if an animal cannot move it would either not be able to hunt for food and die or would have to develop a way to attract prey to them such as the venus flytrap.

Natural Selection: the process by which inheritable traits become more common in a population over successive generations

Natural selection is important for organisms in an ecosystem because it allows the best traits of a species to survive through generations. The best traits allow the species to survive and reproduce.

An example of natural selection in the ocean is the ability to camouflage. Fish that are the hardest to see will survive because the predators in their environment cannot find them while the fish that are easiest to see will be eaten and not survive. The surviving fish will be able to pass down their genes into the next generation that will be able to hide from predators. The fish that was eaten will not be able to survive and reproduce so it will not pass down its disadvantageous traits into the next generation. The next generation will be able to hide from its predators and continue to survive. If a fish's environment starts to increase in its number of predators then the fish would have to develop a way to survive like camouflage.

Comment Stream

View Older Posts
3 years ago

@madisonlamb Thank you

3 years ago

@laurencochran I'll look for more pictures

2 years ago

I agree with this because th limiting factors and energy roles are correct.

2 years ago

Good choice of vocabulary and pictures 👌👍

2 years ago

Go back and look at the instructions for steps 3& are missing some information.

2 years ago

wonderful format 😊

2 years ago

@evelynvo Very nice job!! You can tell you put a lot of effort into this! 😀

2 years ago

Love the format and the effort put into it! I also love the organization! I love this!

2 years ago

@dianegunnip I'm not really sure what I'm missing but I'll work on it.

2 years ago

@briannasepulveda @elizabethgleason @michaelvarner @angelalangford @joshuadimanche Thanks for all the feedback! I tried my best.