Three Rock Pools is a free printable Grade 3 science worksheet on using rock-pool counts to argue which sea creatures survive well where, aligned to NGSS performance expectation 3-LS4-3. It prints 7 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two students in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 19 of 25 · the same problems every time you open this link.
Set 1 has all 25 in a single PDF. All 25 sets ask different questions.
Three Rock Pools
3-LS4-3
NameDate
Read the record, then answer the questions.
1.Read the record, then answer the questions.
Three Rock Pools
Counts the class made in three rock pools at low tide: one high on the shore, one in the middle and one near the sea.
WHAT WE COUNTED
High pool (out of the sea for most of the day): 30 barnacles, 6 limpets, some green seaweed, no starfish, no kelp
Middle pool: 12 limpets, 9 sea anemones, 4 crabs, brown seaweed, no kelp
Low pool (covered by the sea for all but an hour a day): 5 starfish, 11 sea anemones, 6 crabs, kelp, 3 small fish
The high pool's water was the warmest, and its level dropped most in the sun.
We counted for ten minutes at each pool.
1. Which pool had the most kinds of living thing?
2. Why count for ten minutes at each pool?
3. Where was the kelp found?
4. Why might starfish survive well in the low pool but not in the high pool?
2.Why are there no coral reefs in polar seas?
A.Polar seas are too salty for fish
B.Reef coral needs warm water to survive
C.Polar bears eat the coral
3.Why do some animals in the deep sea have no working eyes?
A.The water is too salty for eyes
B.They are always asleep
C.There is no light to see by down there
4.Why does kelp grow only in shallow water?
A.It needs sunlight, which cannot reach the deep sea
B.It cannot swim
C.It is too heavy for deep water
5.A limpet clamps tight to a rock when the tide goes out. How does that help?
A.It stops it drying out until the sea comes back
B.It helps it swim
C.It keeps it warm
6.Why can mussels and barnacles live where the waves crash?
A.They swim away from every wave
B.They are fixed tight to the rocks, and the waves bring them food
C.Waves cannot reach them
7.Why do so many kinds of fish live on coral reefs?
A.Reefs are cold and dark
B.The reef gives them food and places to hide
C.Fish cannot live anywhere else
LessonPrint · 3-LS4-3 · Set 19 · free to copy for classroom use
Answer key — Three Rock Pools
Set 19. Prints on its own sheet.
1.1. The low pool, near the sea. 2. So each pool was searched for the same time and the counts can be compared. 3. Only in the low pool. 4. The low pool is covered by the sea nearly all day, while the high pool warms up and its water drops in the sun.
2.Reef coral needs warm water to survive
3.There is no light to see by down there
4.It needs sunlight, which cannot reach the deep sea
5.It stops it drying out until the sea comes back
6.They are fixed tight to the rocks, and the waves bring them food
7.The reef gives them food and places to hide
Last reviewed 2026-09-05. Aligned to 3-LS4-3 of the Next Generation Science Standards.