1. Interdependence in the Ocean
Chapter 21

2. AIM To identify important nutrient cycles in the ocean environment
To Explain Characteristics of ocean food chains and webs
Discuss the importance of symbiotic relationships in the sea
Describe how succession occurs in marine environments

3. Interdependence
Is a relationship in which marine organisms interact in a mutually dependent way.
Based on the need for food and or protection
Example: Schooling bait fish, killer whale pods, or Nemo (clown fish) and sea anemones

4. Marine Ecology
The study of the interactions of living things with each other and their ocean environment
Biotic factors- living things in the ocean
Abiotic factors- non-living components of the ocean environment (water, temp, light, minerals, dissolved gases

5. The interaction between biotic and abiotic factors within an environment make up an ecosystem
Within ecosystems, many resources are recycled
The most important include carbon, oxygen, nitrogen, sulfur, and phosphorus

6. Carbon Cycle All organic compounds contain carbon
Photosynthesizing plants and algae take in carbon in the form of Co2, and produce carbohydrates (organic compounds)
Animals take in carbon compounds when they eat the plants
Animals give off Co2 through respiration or when they die

7. Thus making carbon available for plants once again
In the marine environment dissolved carbon(carbon dioxide) is taken up by plants and animals and combined with calcium to produce calcium carbonate
Which makes shells and body parts
Calcium and carbon are again released into the marine environment when the organisms die and decay

8. Oxygen Cycle
O2 is the crucial element needed for cellular respiration in both plants and animals
Plants release oxygen into the atmosphere when they split water molecules during photosynthesis
Carbon dioxide-oxygen cycle involves the interdependence between plants and animals

9. Oxygen in water Oxygen in air 21% Oxygen in water 0 - 15 Ppm (mg/l)
Much less oxygen is available to aquatic organisms
then there is available to terrestrial organisms
Oxygen enters by:
Photosynthesis of plants, algae,
bacteria, protists
Wave action, wind, currents,
waterfalls

10. The solubility of oxygen varies with salinity.
As salinity increases
The solubility of oxygen decreases

11. The solubility of oxygen in water varies with temperature.
As temperature increases
Oxygen solubility decreases

12. Respiration removes oxygen from water
The oxygen produced as a by product of photosynthesis
may actually bubble out of aquatic environments during
daylight hours on warm summer days because of its
low solubility.
Pollution may cause overgrowth
of photosynthetic organisms
Sewage - nitrates

13. Detergents - phosphates

14. Lawn fertilizer –
both nitrates
and phosphates

15. These blooms may produce tremendous amounts of
oxygen during the day.
At night they continue to respire
without photosynthesizing
They compete with the animal populations for oxygen.

16. The combined effect is to decrease the oxygen level
below that in which the animals can survive -
Causing fish kills
Fish kills most frequently occur
on very hot days.
During the early morning.
In areas of poor circulation
To large groups of schooling fish

17. Fish Kills due to
harmful algal blooms on the
West coast of Florida
Dinoflagellate –
Gymnodinium breve

18. These blooms of organisms may color the water producing
red stained water - red tides.
Some red tide organisms produce toxins which may affect
fish and other animal populations

19. Suspected toxic algae bloom leaves thousands of fish dead
“Marine experts from the World Wildlife Fund have flown to Kenya to investigate the death of thousands of marine wildlife believed to be caused by toxic algae. Following what WWF called an apparent "freak, off season" bloom of toxic algae, huge numbers of dead fish, including manta rays,
sharks and tuna have washed up on the Kenyan shore”

20. Thirteen researchers who worked with dilute toxic cultures
of Pfiesteria sustained mild to severe adverse health
impacts through water contact or by inhaling toxic aerosols
from laboratory cultures.

21. Intense local pollution was implicated in six events in 1999,
accounting for approximately 15,000 fish mortalities. The
largest single event in this category occurred December 29th
after a discharge of #2 heating oil from a local elementary
school killed approximately 12,000 fish in
Spring Branch, Baltimore County.

22. Photo 4. The numbers and extent of hypoxic episodes are increasing,
especially in areas important to commercial fishing.
Concern is spreading as the media report the consequences of these events.

24. This type of plankton,
Ceratium tripos,
was responsible for
a hypoxic event
in the New York
Bight in 1976.

27. Availability of Nutrients
Coastal and shallow waters have a greater abundance of life-forms than does the open ocean
Why do you think this is true?

28. Photosynthesis can only occur relatively close to the surface top 100 meters
What is this area known as?
Plants and algae need nutrients that are released by bacterial decay
In the open ocean these nutrients sink to the bottom where there is no light

29. In shallow water almost all nutrients are available to plant life
This plant life supports all other life
Limited phytoplankton production limits the growth of all life-forms dependent on those plants

30. Two most important conditions
Availability of nutrients to photosynthetic organisms and;
In deep water upwelling of vital nutrients
In either case without the availability of nutrients and light to support phytoplankton all other aspects of the food chain are affected

31. Food Relationships Producers, consumers, decomposers,
carnivores, herbivores, omnivores, predators, and prey; parasites and hosts
All of these components of the food chain are dependent upon the success of other parts of the chain

32. Food Chains
When one type of living organisms serves as food for another organism which serves as food for the next organisms in the chain
Example:
Phytoplankton—zooplankton—shrimp—herring--?--?

33. Refer back to the food relationships which is the first in the food chain?
Food chains vary in length but must have at least one producer and consumer

34. Primary consumer: first animal in the food chain (consumes the producer) (zooplankton)
Secondary consumer: feeds on primary (shrimp)
Tertiary consumer: feeds on secondary (fish or squid)

35. Each feeding level is called a trophic level
Through each trophic level there is a transfer of chemical energy
This chemical energy transfer begins with the producer and moves through the chain
Eventually the chemical energy is re-introduced to be recycled

36. Omnivores- animals that consume both plants and animals
Scavengers- organisms that eat the remains of already dead plants and animals
Decomposers- break down already dead matter into smaller particles (microbes)
Now thought to be up to 1/3 of biomass

37. Decomposer bacteria and fungi also known as Saprophytes
Decomposers break down dead matter into organic molecules and simple compounds which are taken up by producers and recycles energy back into the food chain

38. Food Webs When food chains interconnect they form food webs
These include predator/prey, omnivores relationships
Predators can often withstand the loss of one food source
However what are the impacts?

39. What happens to secondary consumers if its only food source is eliminated?

40. Food Pyramids
In a food pyramid the population at each higher trophic level is smaller than the one below it
Success of a food pyramid
depends entirely on the
decreasing population
higher up the pyramid

41. Factoids
Only about 10% of absorbed energy is transferred to the next trophic level
In order for a shark to produce 10 kg of body tissue it must consume 100 kg of food which was produced as a result of the consumption of 1000 kg of food

42. Thus food pyramids demonstrate there is more energy available at the bottom of the pyramid
Be sure to understand: succession in marine environments, ecological succession, various communities, and succession on islands

43. Symbiosis in the ocean
Symbiosis: close relationship between different species, usually beneficial
Mutualism: relationship in which BOTH species BENEFIT
Commensalism: relationship in which one organism benefits and the other is not affected
Parasitism: relationship in which one species benefits (parasite) while the other is harmed (host)