Authors: Grace Yu; Sources: National Geographic, Unsplash
Carrying Capacity
INTRODUCTION
There are many different species living in many different ecosystems on Earth. Each of these unique species has its own carrying capacity within its respective ecosystem, which is determined by abiotic factors.
“Carrying capacity can be defined as a species’ average population size in a particular habitat. The species population size is limited by environmental factors like adequate food, shelter, water, and mates. If these needs are not met, the population will decrease until the resource rebounds.” — National Geographic
ACTIVITY 1
Plastic Tank Carrying Capacity
Materials: 2 different sized plastic tanks/containers, rocks/other weighted objects, water // Duration: 5 minutes
Measure out enough water so that the smaller container is filled up almost all the way (smaller container is shorter in height)
Place the weighted objects into the water (there should be water spillage)
Water spilling out of the container (the ecosystem) represents exceeding the carrying capacity for a species
Pour the same amount of water in the smaller container into the larger container
Place the same weighted objects into the water of the larger container (there should be no spillage)
Note that the same “species” and the same amount of water were present in both containers (ecosystems), but because the two containers (ecosystems) were different, the carrying capacities were also different.
ACTIVITY 2
“A Delicate Balance”
Source: National Geographic // Duration: 5 minutes
Gain knowledge on the purple sea urchin overpopulation crisis
Explore the impact of a species exceeding its carrying capacity on the rest of the ecosystem
