Question

impacts to populations review
fish population in a pond
directions: use the graph above to match the scenario to the correct years. cut/paste.
the pond dried up and all the fish emigrated to a new pond.
10 fish immigrated to this pond from another pond
predators decreased and 10 fish were born.
a disease came through and 20 fish died.
resources were abundant and 20 new fish were born.

how did the population change? (increase / decrease)

event from above

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between year 1 and year 2

between year 2 and year 3

between year 3 and year 4

between year 4 and year 5

between year 5 and year 6

Explanation:

1. Year 1 to Year 2: The population rises from 10 to 20 (a 10-fish increase). This matches the scenario of 10 fish immigrating or 10 being born; the 10-fish immigration is the direct 10-unit increase match.
2. Year 2 to Year 3: The population jumps from 20 to 40 (a 20-fish increase). This aligns with abundant resources causing 20 new fish to be born.
3. Year 3 to Year 4: The population drops from 40 to 20 (a 20-fish decrease). This matches a disease killing 20 fish.
4. Year 4 to Year 5: The population rises from 20 to 30 (a 10-fish increase). This fits the scenario of fewer predators leading to 10 fish being born.
5. Year 5 to Year 6: The population drops from 30 to 0 (total loss). This matches the pond drying up and all fish emigrating.

Answer:

Time Period	How did the population change? (increase / decrease)	Event from Above
Between Year 2 and Year 3	Increase	Resources were abundant and 20 new fish were born.
Between Year 3 and Year 4	Decrease	A disease came through and 20 fish died.
Between Year 4 and Year 5	Increase	Predators decreased and 10 fish were born.
Between Year 5 and Year 6	Decrease	The pond dried up and all the fish emigrated to a new pond.