The Marine Research Facility Malibu High School P r e s e n t s c o l o g y basics 5.

THE 10% RULE and ECOLOGICAL PYRAMIDS

The Laws of Thermodynamics and FOOD CHAINS !

The 10 % RULE !

trophic level is used to keep the The maximum amount of ENERGY that passes from one trophic level to the next is 10%. 90% of the ENERGY at each trophic level is used to keep the organisms alive and is converted to HEAT.

Always start with the SUN.

HEAT 90% of the ENERGY captured by PRODUCERS is used to keep The 10% RULE ! PHYTOPLANKTON 90% of the ENERGY captured by PRODUCERS is used to keep themselves alive (converted to heat). HEAT Max. 10 % to HERBIVORES

of the pyramid of biomass because their ENERGY comes direct PRODUCERS HERBIVORES 1st Order CARNIVORES Producers are the BASE of the pyramid of biomass because their ENERGY comes direct from the SUN. 2nd Order CARNIVORES 3rd Order CARNIVORES

HEAT Max. 10 % to CARNIVORES The 10% RULE ! 10% 90% 90% was used PHYTOPLANKTON 10% ZOOPLANKTON 90% HEAT 90% was used to keep the HERBIVORES alive. Max. 10 % to CARNIVORES

PRODUCERS HERBIVORES 1st Order CARNIVORES 2nd Order CARNIVORES exist on only 10% of the ENERGY from PRODUCERS. 2nd Order CARNIVORES 3rd Order CARNIVORES

HEAT The 10% RULE ! 10% 10% 90% 10% PHYTOPLANKTON ZOOPLANKTON 1st Order CARNIVORES 90% HEAT 10% Max. 10 % to 2nd O. CARNIVORES

1st O. Carnivores are max.10% PRODUCERS HERBIVORES 1st Order CARNIVORES 2nd Order CARNIVORES 3rd Order CARNIVORES 1st O. Carnivores are max.10% of HERBIVORES.

The 10% RULE ! 10% 10% 10% 2nd Order CARNIVORES PHYTOPLANKTON ZOOPLANKTON 10% 1st Order CARNIVORES 10% 2nd Order CARNIVORES

ENERGY left near the top. PRODUCERS HERBIVORES 1st Order CARNIVORES 2nd Order CARNIVORES 3rd Order CARNIVORES There isn’t much ENERGY left near the top.

PRODUCERS HERBIVORES 1st Order CARNIVORES 2nd Order CARNIVORES The 10% RULE . . . 2nd Order CARNIVORES 3rd Order CARNIVORES ...results in this ECOLOGICAL PYRAMID

PRODUCERS - 1000 HERBIVORES - 100 1st Order CARNIVORES - 10 2nd Order The 10% RULE . . . 2nd Order CARNIVORES - 1 3rd Order CARNIVORES 0.1 ...is used to help predict NUMBERS.

1000 100 10 1 0.1 The 10% RULE . . . ...is used to help predict BIOMASS. 0.1

The ecological pyramid at ZUMA. PHYTOPLANKTON 10% ZOOPLANKTON 10% 1st Order CARNIVORES 10% 2nd Order CARNIVORES

1,000 100 10 1 Population size ratios at ZUMA. 10% 10% 10% individuals

Biomass at ZUMA. pounds 1,000 pounds 10% 100 pounds 10% 10 10% 1 pound

? 1 lb. For every 1 lb. of halibut, how many lbs. of Zalophus can be supported ? 1 lb. ?

1 lb. 0.1 lbs For every 1 lb. of halibut, 0.1 lbs. of Zalophus can be supported ! 1 lb. 0.1 lbs

30,000 lbs. 3,000 lbs. For a 30 lb. halibut, 30,000 lbs. of phytoplankton are necessary ! PHYTOPLANKTON 30,000 lbs. 3,000 lbs. ZOOPLANKTON 1st Order CARNIVORES 300 lbs. 30 lbs. 2nd Order CARNIVORES

REVIEW CHECKPOINT: 1. What is the 10% rule ? 2. Where does most of the ENERGY go at each trophic level ? 3. What 2 things can the ecological pyramid help predict? 4. If there are 14,963 kg of anchovies at Zuma, tell how many kg are predicted: a. Zooplankton c. Halibut b. Phytoplankton d. Zalophus

Coming soon: FOOD WEBS !