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 23 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. What does this survey not tell you?
2. Barnacles were most common in the high pool. What does that suggest about them?
3. Why count for ten minutes at each pool?
4. Which pool had the most kinds of living thing?
2.Why can mussels and barnacles live where the waves crash?
A.They swim away from every wave
B.Waves cannot reach them
C.They are fixed tight to the rocks, and the waves bring them food
3.A limpet clamps tight to a rock when the tide goes out. How does that help?
A.It keeps it warm
B.It stops it drying out until the sea comes back
C.It helps it swim
4.Why do so many kinds of fish live on coral reefs?
A.The reef gives them food and places to hide
B.Reefs are cold and dark
C.Fish cannot live anywhere else
5.Why are there no coral reefs in polar seas?
A.Polar bears eat the coral
B.Polar seas are too salty for fish
C.Reef coral needs warm water to survive
6.Which ocean habitat could a polar bear survive in?
A.The floor of the deep dark sea
B.A warm coral reef
C.The sea ice of the Arctic
7.Why do some animals in the deep sea have no working eyes?
A.They are always asleep
B.The water is too salty for eyes
C.There is no light to see by down there
LessonPrint · 3-LS4-3 · Set 23 · free to copy for classroom use
Answer key — Three Rock Pools
Set 23. Prints on its own sheet.
1.1. It does not tell you what lives in the pools at high tide. 2. Barnacles can survive being out of the sea for most of the day. 3. So each pool was searched for the same time and the counts can be compared. 4. The low pool, near the sea.
2.They are fixed tight to the rocks, and the waves bring them food
3.It stops it drying out until the sea comes back
4.The reef gives them food and places to hide
5.Reef coral needs warm water to survive
6.The sea ice of the Arctic
7.There is no light to see by down there
Last reviewed 2026-09-05. Aligned to 3-LS4-3 of the Next Generation Science Standards.