4th Grade:

rocky Shores

Overview

Rocky shores and intertidal habitats make up the majority of Oregon’s shoreline – about 62%, according to the Oregon Parks and Recreation Department. This defining feature of our coast not only provides habitat for numerous unique species of seaweeds, fish, mammals, invertebrates, and birds, but is an important resource for humans as well. Rocky shores and their tidepools serve as nurseries for juvenile animals, some of which grow up to become important staples for the commercial fishing industry, such as Rockfish and Red Rock Crabs. In Oregon, the fishing industry is a significant part of our state economy, contributing around $150 million to the economy annually. Our state also has a number of Marine Reserves, protected areas where human use is limited and wildlife thrives, providing high biodiversity zones that then spread and help restore populations in surrounding waters.

Oregon’s wild shores are also an important part of our history and culture. Native peoples have been harvesting shellfish, salmon, and plants along the coast for at least 12,000 years. Before Oregon’s highways were built, brave travelers used the beaches as roads for cars and horses to travel between coastal towns. Today, all people can freely access the coast thanks to the Oregon Beach Bill. Our beaches give us a place of sanctuary and peace, a space where we can connect with friends and loved ones, and inspire a sense of wonder. We encourage you to tap into these deeply personal, intrinsic connections to the coast with your students to make the science more meaningful!

NOTE: This unit is adapted from Oregon Coast Aquarium's Exploring Oregon's Rocky Shores curriculum. Click here for the full Teacher's Guide or contact our Teacher Programs Manager for more information.

Classroom Investigations

Field Studies

Authentic Project

Additional Resources

Driving Question

How do animals survive in Oregon's rocky shores and tidepools?

Essential Concepts

Oregon's rocky shores are difficult environments with lots of challenges for living things.

Rocky shore organisms have developed a number of adaptations to survive their harsh environmental conditions.

People can negatively impact rocky shores, but can also help protect these places and the creatures that live there.

Related Standards

Next Generation Science Standards - Oregon K-12 Science standards

3-LS4-3: Construct an argument with evidence that in a particular habitat some organisms can survive well, some survive less well, and some cannot survive at all.

4-LS1-1: Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.

4-LS1-2: Use a model to describe that animals receive different types of information through their senses, process the information in their brain, and respond to the information in different ways.

4-ESS3-2: Generate and compare multiple solutions to reduce the impacts of natural Earth processes on humans.

Entry Event

Imagining A Tidepool

ENGAGE (5 mins): To introduce this unit and help students to recall their own experiences, ask students to show by a raise of hands who has been to a rocky shore. Ask them to describe their experience – what did they see, hear, smell, and feel? Write down these responses on the board. If you have a class of students who have largely never been to the beach, it will help to begin by showing this video and asking them to describe what they notice.

EXPLORE (20 mins): Next, tell students that they are going to create a picture of what they think the rocky shore is – what it looks like, what lives there, anything they wish to include. This should be an open-ended challenge with very little guidance given, to encourage students to generate the drawing on their own. This serves as an excellent pre-unit assessment of their current knowledge. Give each student a piece of paper and writing implements with which to draw and allow them to do so uninterrupted.

EXPLAIN (5 mins): After sufficient time has been given for them to draw, ask them to describe what they created, pointing out the various features and explaining why they put them there. Do not correct or add to what they have drawn; again, the point of the exercise is to activate students’ prior knowledge and to assess what they already know and understand (or don’t) about rocky shores.

EVALUATE: Can students clearly explain the features of their drawings?

NOTE: Make sure you collect and save the drawings. (They can also be displayed around the room!) This activity will be used again at the end of the unit to compare their baseline knowledge to what they learned.

EXPAND (15 mins): If time allows, read a related book such as: Life in a Tidepool by Allan Fowler (gr. 1-2, Lexile: H)), In One Tidepool by Anthony Fredericks (gr. PreK-4, Lexile: NP), Between the Tides by Fran Hodgkins (gr. PreK-3), and Science Chapters: All About Tide Pools by Monica Halpern (gr. 2-4, Lexile: P) are good options for elementary students.

Classroom Investigations

Moving With The Tides

Purpose: Conditions at the tidepools are always changing, and sometimes, the locations of the animals living there change with it! Some species are stuck to the rocks and don’t move around, but others are mobile, and they follow the tides as the water moves up and down the rocks. In this activity, students will learn how rocky shore animals move into different tidal zones throughout the day during high tide, mid tide, and low tide.

Time needed: 15 minutes for prep, 45-50 minutes for activity

Materials: Sidewalk chalk (if doing activity outdoors) or masking tape (if doing indoors); “Critter Cards” printed and cut out

Preparation (before students arrive) (15 mins): Set up the activity area, preferably outside on a paved area, or in a cleared space in a large classroom. You will need to create the five intertidal zones on the ground using sidewalk chalk or masking tape to designate each area, in the following order: Subtidal, Lower Intertidal, Mid Intertidal, Upper Intertidal, Splash Zone. Each area should be large enough for several students to stand in it a time. Label each zone with the chalk (or written labels). Next, print and cut out the “critter cards” provided above. Depending on your class size, you will have 2-5 students playing the role of each creature, so make sure you make enough copies for your class.

ENGAGE (15 mins): Using the information provided on Oceanscape Network, introduce students to the changing conditions found at the rocky shore throughout the day. Describe how temperature, salinity, and oxygen levels are different at high tide versus low tide. Ask students, what would you do if you were standing outside and it started to rain? What if it got really hot? Would you stay where you are? Of course not! Students would move somewhere to find shelter, and rocky shore organisms do the same thing: they move with the tides to where they can find more favorable conditions. Some animals prefer very wet conditions, while others prefer dry conditions, and still others can tolerate both dry and wet. Finally, describe the five intertidal zones found at the rocky shore, describing the wetness versus dryness typically found in each zone. Utilize the board to provide students a visual aid of how the intertidal zones are arranged.

EXPLORE (25-30 mins):

Tell students they are each going to play the role of a different rocky shore animal. They will each get a “Critter Card” describing their animal, and how well they can cope with wet and dry conditions. It will also tell them what zones they can be found in throughout the day: at Low Tide, at Mid Tide (between high and low tides), at High Tide, and at extreme high and low tides. Hand out the Critter Cards. Depending on your class size, you will have 2-5 students playing the role of each creature. Give students a few moments to review the information on their Critter Card.
Next, show students the “intertidal zone” – the activity area you set up earlier. Tell students you will be announcing the tides as they change in your “intertidal zone”. Point out the various intertidal zones, ensuring students know where each is and that the labels are clearly visible.
Begin the activity at “Mid Tide”. Tell students it is now Mid Tide, and they should begin by finding their correct intertidal zone for that time of day. Then, tell students that the tide is rolling in. Use or adapt the following narrations: The tide is coming in. Slowly, the water creeps up the rocks, filling empty tidepools, reaching higher and higher until – HIGH TIDE!
Once High Tide is announced, students should change zones based on where their animals would now be found. Then, the tide begins to recede again: Water levels begin to fall. The upper rocks become uncovered as the tide goes out, washing down to pool in the Mid Intertidal Zone – MID TIDE! Now students should move to the intertidal zone where they are found during Mid Tide, the time between High and Low Tide.
Continue on to Low Tide: The tide is going out more and more. Water is left behind in the tidepools to warm in the sun, as the sea washes out along the Lower Intertidal zone – LOW TIDE! Once again, students should move to the zone their animal is most comfortable in during this tidal phase.
Repeat the tide cycle as many times as you would like, perhaps speeding up your announcements to add an element of “racing” across the activity area (but remind them this process takes many hours in nature!). The chart at the bottom of this page shows the correct location of each species during each phase of the tide cycle.

EXPLAIN (5 mins): Ask students to share their observations about how the “critters” moved as the tides changed. Were they able to observe any patterns? Students may be able to note that in general, animals moved down into the lower zones during low tides, and up into the upper zones at high tides. During most of the tide cycle, most of the organisms were somewhere between the Subtidal Zone and the Upper Intertidal. This is because most rocky shore organisms are adapted to some degree to living underwater and so cannot survive in the driest Splash Zone. One exception to this pattern is the Sea Lion, which basks on the rocks in the Splash Zone at High Tide, and is able to swim into the Lower Intertidal during High tides.

EXPAND (5 mins): Ask students to think about how rocky shore animals that cannot move – such as barnacles and mussels – cope with the changing tide conditions. What might they do to stay wet and cool during low tides? Spend a few minutes brainstorming, but acknowledge it’s alright if they don’t know the answer – they will learn more about these organisms’ adaptations during a later activity.

EVALUATE: Can students name the five intertidal zones found at the rocky shore? Are they able to describe the conditions found at each, and how these conditions change throughout the day as the tides go in and out?

The Sun, The Moon, and the Tides

Purpose: Now that students know a little about how the tides affect rocky shore organisms, it’s time to learn how tides work and why they happen! In this activity, students will use their bodies to model how the changing positions of the Sun, Moon, and Earth create tides.

Time needed: 30-45 minutes

Materials: Space for all students to sit in a circle and move around

ENGAGE (5-10 mins): What is gravity? Elementary students should be familiar with this word, but it will be helpful to review. Gravity is the force that pulls an object towards the center of the Earth. It’s why we can stand on the surface of Earth and not float away into space, and why a ball falls to the ground when it is released. It’s not actually falling, but being pulled down by Earth’s mass. The larger an object’s mass, the more gravity it exerts. That’s why astronauts on the Moon must bounce along slowly rather than walk as they can on Earth – the Moon is much smaller than the Earth, and thus has much less gravity pulling the astronauts down.

Though the Moon is small, it is large enough and close enough to Earth to have a strong gravitational force on Earth’s surface. And because Earth, too, is exerting a gravitational force on the Moon, the Moon is trapped in an orbit, circling around the Earth once every month. Our oceans are stretched and pulled towards the Moon as it circles around our planet. This rise and fall of the oceans towards the passing Moon is what causes the rise and fall of water along our shores known as tides.

Use a video as part of your introduction to help visualize concepts, such as this one (a good overview) or this one (a simple animation).

EXPLORE (10 mins):

For the first part of this activity, have students sit on the floor in a tight circle. These students represent the oceans on Earth’s surface. Select one student to play the Moon and ask him or her to walk slowly around the outside of the circle. Tell students to lean their bodies towards the Moon as it passes; this represents the gravitational pull of the Moon on the oceans, causing the water to rise.
After one or two revolutions of the Moon, pause and explain that it’s a little more complicated than that. The Moon is also pulling on the Earth itself – pulling it AWAY from its oceans on the side opposite the Moon! This causes higher seas on the opposite side of the planet, too.
Have the Moon walk around the circle again, only this time, have students by the Moon lean towards him or her as they pass, and have students on the opposite side of the circle also lean back, away from the Moon.
Continue until students can see the pattern of where sea rise occurs relative to the Moon.

EXPLAIN (5 mins): Explain that the students who are leaning out – either by the Moon or on the opposite side – represent the areas on Earth where it’s high tide. The students not leaning out represent areas of low tide.

EXPAND (15 mins): Introduce a complication to this pattern: the Sun! The sun is much, much bigger than either the Moon or the Earth, but it is also much further away. Therefore, it exerts a gravitational force on Earth, though a weaker one than the Moon. But it’s strong enough that when joined up with the Moon’s gravity, it causes a noticeable change in the tides.

Pull another student from the circle to play the Sun. Begin by placing the Sun next to the Moon so that all three planets are lined up. Explain that when the planets are lined up this way, there is an extra strong force on Earth’s oceans – have the students closest to the Moon and Sun, and on the opposite side, lean ALL the way back to show the increased pull. When the planets are lined up this way, tides are extra high; these are called Spring Tides.
Next, have the Sun move around the circle so that the Sun and Moon are at a right angle to each other. (Note that the Sun doesn’t actually move around the Earth – the Earth moves around the Sun – we are just doing it this way to demonstrate!) Ask students which way they think they should lean when the Sun and Moon are positioned this way. They will probably be torn about whether they ought to lean more towards the Sun or towards the Moon – and they’re correct! When the planets are at a right angle like this, the gravity of the Sun and the Moon are competing, and the forces more or less balance each other out.
Tell the students to lean towards the area between the Sun and Moon (or away from, on the opposite side), but only a little. When the planets are arranged this way, there is not much change in water levels even at high and low tides – these are known as Neap Tides.
Finally, ask both the Moon and the Sun to walk around the circle, and challenge students to lean towards or away from the planets as they pass without your guidance. The Moon should walk more quickly than the Sun to demonstrate that the Moon rotates around Earth much more quickly than the Earth rotates around the Sun (one month versus a year).

EVALUATE (5 mins): Are students able to correctly demonstrate the gravitational forces of the Moon and Sun on the oceans without your guidance? Can they describe this process aloud?

Invent A Rocky Shore Creature

Purpose: In this activity, students invent a new species which can withstand the tough conditions in a tidepool, inspired by real tidepool organisms and their adaptations. This activity works best after a field trip to Oregon Coast Aquarium or a rocky shore area, where they can observe firsthand tidepool animals and their unique features.

Time needed: 40-50 mins

Materials: internet connection and screen to view video and slideshow of tidepool animals; craft supplies such as: Suction cups, Play dough, Tape, Glue, Velcro, Yogurt cups, Cardboard, Pipe cleaners, Hot glue sticks, Plastic eggs, Popsicle sticks, Toothpicks, Felt or fabric, or whatever else you have on hand that could mimic tidepool creature features!

ENGAGE (10 mins): Remind students that waves bring both vital resources (food, water, salt, cool temperatures) and challenges (big crashing waves, driftwood and other debris, predators) to animals living in rocky shore environments. Tidepool animals use a variety of physical features and behaviors to help them survive in this habitat. Using the species picture on the Tidepools page at Oceanscape Network, ask students to name some adaptations that tidepool animals use to survive. These may include the ability to stick with a muscular foot, byssal threads, or tube feet which helps them hold on to the rocks and not get swept away; a hard shell which provides protection from big crashing waves and any debris that might be in the water; the ability to bend which helps them have a better grip on curved and bumpy rocks, and to flex with the waves; and a rounded body shape, which allows water to easily flow over and around them. Note that most rocky shores animals use a combination of these abilities to survive! Then, have them watch this video of crashing waves in a tidepool and ask them to describe what they noticed. Write down these descriptive words on the board. Would they be able to survive in these conditions without being washed away? Tell students they are going to design a tidepool animal they think could survive crashing waves without falling apart or being washed away. You can choose to have students work individually or in small groups. They should use real tidepool animals for inspiration, so remind them that they can refer to the slideshow and the list of features you created as a class. Distribute the crafting materials or give instructions for collecting them from the front.

EXPLORE (20-25 mins): Move around the room as students begin to create their creatures, encouraging them to think creatively and to make predictions about what might happen to their organism if a big wave hit it. If time and resources allow, have students test their creations by placing them in a tub or sink filled with a few inches of water. Use a dustpan or their hands to create “waves” and see how their design holds up. If it falls apart, have students think about why it didn’t work and what they could do to improve the design. Build, test, and rebuild designs for as long as time allows!

EXPLAIN (5-10 mins): Have students demonstrate their species designs to their classmates, highlighting the ways their organism stands up to waves and its other adaptations for survival. Ask students to relate these structural characteristics to real tidepool animal adaptations and features.

EXPAND (if time allows): Discuss how, like animals, people have to be able to survive challenges in their own “habitats”. Ask students to think about things buildings have to withstand (wind, rain, fire, etc.) so that humans can live and work safely inside. What are some ways people build buildings to be strong and stable? If time allows, take a tour of the school and look for safety features such as fire sprinklers and fire extinguishers, explore windows and doors to see how rain and cold is kept out, look for rain gutters and drains, etc. Compare the structures you see to any similar animal features you have discussed, or the ways that students designed their own creatures.

EVALUATE: Do students reference prior knowledge and vocabulary gained throughout this unit? Are they able to describe what they learned through the design process and how that was applied to changes they made to their species? Do they use detail or specific examples when describing ways their design reflects real tidepool animal adaptations?

Tidepool Obstacle Course

Purpose: In this activity, students will learn how they can take personal responsibility to care for the environment and its creatures when visiting the tidepools by following “good tidepooling manners”. They will navigate through an obstacle course with items representing trash, tidepools, and sea creatures, demonstrating the proper choices they should make for each.

Time needed: 15 mins for prep, 45-50 mins for activity

Materials: open floor space; sidewalk chalk (if doing activity outside) or masking tape (if doing activity inside); props representing tidepool animals and litter (see PREP section below)

PRIOR PREP (15 mins): Set up the obstacle course. You may choose to set this up in an open space in your classroom, or outside on an open paved area. There are a number of ways you can design your obstacle course: for younger students, a traditional hopscotch layout works well, while for older students you may want to make it more complex. Use the sidewalk chalk, if outside, or masking tape if inside, to lay out the course that students should follow. Mark some areas with a large X to represent a tidepool full of water. How challenging you make it should be based on the age and abilities of your students (see next page for an example). Finally, set out your props throughout the obstacle course. You will need items to represent both tidepool animals and human trash, such as: Pictures of tidepool animals, printed and cut out, OR Toys to represent animals (rubber duckies etc.); items representing pollution such as plastic bags, water bottles, soda cans, chip bags, etc.

ENGAGE (10 mins): Ask students if they have to follow certain rules or manners around their house. Ask them to share what some of those rules for good behavior are (these may include manners at the dinner table, with their siblings, etc.). Tell students that when they go to the tidepools, there are certain manners they must follow as well. These guidelines for good behavior help to keep both them and all the creatures living there safe. Then, using the list below, introduce the rules for “good tidepooling manners”. Engage students by asking them to volunteer their own ideas for proper behavior when visiting the rocky shore.

EXPLORE (30 mins):

Have students gather around the outside edges of the obstacle course. Tell them they are going to pretend it’s the real rocky shore. Point out the X’s, the trash, and the pictures or objects representing the animals, and tell students what they each represent. Tell students they are going to take turns navigating the obstacle course, following the rules for good tidepooling manners that you just went over. For the obstacle course, this means:
- - Watch your step – don’t step on any of the “critters”, or in the “tide pools”
  - Touch gently – they can look at and touch the “critters”, but not pick them up or move them
  - Leave no trace – anything they accidentally kick or displace must be moved back to its original position
  - Clean it up – each student should collect as much trash as they can along the way
  - Never turn your back on the waves –designate one side of the room as the “ocean” and tell students they can never have their backs turned to it
Monitor each student as they go through the obstacle course and encourage the other students to help you enforce the rules. If they break any of the above rules they are disqualified (or you may allow them to start over, if time allows).
NOTE: To make the activity more exciting for older students, make it a competition! Time each student as they go through the obstacle course; the fastest time wins. Alternatively you can award winners for the most trash picked up. For younger students, you may wish to encourage careful rule-following rather than speed.

EXPLAIN (5 mins): Once all students have had the chance to go through the obstacle course, review the “good tidepooling manners” once more. Tell them that they will need to remember these rules when they go on their field trip to the rocky shore, and encourage them to share these manners with friends and family. Ensure that students understand why they should follow these rules – they are important both for their own safety, and to protect the environment and living things.

EXPAND (5 mins): Ask students what else they can do to help care for rocky shores. Ideas may include sharing the “good tidepooling manners” with their community, not bringing anything that could become litter to the beach, not feeding the birds or other animals at the beach, etc.

EVALUATE: Can students recall all of the “good tidepooling manners”? Can they explain why they are important?

Field Studies

Guided Field Trip Sites and Providers

Yaquina Head Outstanding Natural Area - Interpretive Center

Oregon Shores Conservation Coalition: CoastWatch in Schools (Part of their CoastWatch citizen science program)

The Virtual Field- Rocky Intertidal: Virtual Field Studies you can use to compare with our Oregon Coast

Explore and Discover

Be sure to begin with time for free, unstructured exploration. This will allow students to work out their energy and satisfy their natural curiosity and impulse to explore. When you feel students have had sufficient time to discover on their own and become comfortable with their surroundings, then you can gather the group and facilitate the structured activities.

The simplest activity is to allow students to independently explore, searching for tidepool creatures and identifying them once they are found. Using an identification guide is a great exercise in literacy and using scientific tools. There are a number of free tidepool field guides available online that you can print: check out this one from Oregon State Parks or this one from Cape Perpetua Scenic Area. If you have the funds to purchase field guides, we recommend the Pocket Naturalist Guide to Northwestern Seashore Life, which is both waterproof and lightweight. You can buy this online for between $5-$8; purchase enough copies for every 2-3 students to share.

Counting with Quadrats

A quadrat is a square plot used by ecologists to isolate a standard unit of study area. Scientists use quadrats to understand the populations of a large area by counting the number of organisms found within the quadrat in several different sample spots. Often, the quadrat is divided into smaller squares within it. This is useful in calculating percent coverage of certain species, such as plants or invasive species. This information helps scientists to understand the health of an ecosystem, and is used to develop plans for ecosystem restoration or management.

If you're anywhere on the Oregon Coast, the Oregon Coast STEM Hub has quadrats which you can borrow for free from their supplies. Check out their loaning library at: https://oregoncoaststem.oregonstate.edu/feature-story/%5B

You can also easily create your own quadrats with inexpensive supplies. You will need:

Four ¾ inch pipes of equal length (between 16-20 inches)
Four ¾ inch 90 corner (“elbow”) joints
Sturdy twine or rope
A drill

Making a quadrat

Create your square by attaching the pipes together with the corner joints. If desired, use glue to permanently secure the pipes to the joints.
Use a ruler and permanent marker to mark the half-way points on each pipe to divide the quadrat into four equal squares.
Drill a small hole at each of the halfway points, through both sides of the pipe, on each of the four pipes.
Draw the string through the first set of holes and securely tie it off. Pull the other end of
the string through the holes directly opposite, and tie it off so the string is taut. Repeat this process for the remaining two sets of holes.
NOTE: If time and resources allow, you can even have students work in small groups to create their own quadrats!

Counting Activity

Lay the quadrats (one per every 3-4 students) on top of the rocks or over a tidepool, being careful that they aren’t sitting on any sensitive creatures. Have students work in groups to identify all of the types of organisms they see within the quadrat using their field guides.

Then, distribute clipboards with blank sheets of paper, or student journals. Have students count and record the number of individuals of each species in each square. At the end, they can calculate the total number of individuals of each species by adding up their results from all four squares. Above is a template for how students can set up their page and record their data.

Add some math

To extend math practices back in the classroom, collect and combine all student data, displaying class totals on the board. Then ask students to create a bar graph displaying the results.

Ask students which species were the most common, and why they think those species were most common. Answers should be based on adaptations and tidal zones (i.e., if sampling took place in the Upper Intertidal Zone, species such as the Acorn Barnacle which have adaptations to prevent drying out should be most common). Help guide student understanding based on the activities from this unit they have already completed.

Circles in the Sand

Ask students to collect and categorize things they find on the beach.

Draw two large circles in the sand, labeled biotic (living or once-living things), and human (man-made items). Give students time to collect as much as they can, and sort what they found into the two circles. SAFETY TIP: Be sure to warn students not to pick up anything that looks unsafe, such as glass or sharp objects, and ensure chaperones carefully monitor the activity.

After re-gathering the group around the circles, discuss what they found, pointing out any surprises or mistakes. These may include things students may not identify as biotic but were once living (such as shells and sticks) and potentially confusing items (such as bits of trash that might look like living things or vice-versa).

Point out the amount of trash versus living things they found, and use this to reinforce what they learned about caring for rocky shores during the “Tidepool Obstacle Course” activity.

Complete the activity by asking them to collect all of the items from the “human” circle into a trash bag. You can even sort out what is recyclable and what is not for proper disposal.

Authentic Project

Teaching at the Tidepool

Tell students that they are all going to become TIDEPOOL EDUCATORS! Choose a nearby beach with tidepools, pick a date (or multiple dates), and as a class, visit the site to share their knowledge about different species and tidepooling etiquette with tidepool visitors.

You'll want to spend some time preparing students for this activity. They may want to create informational pamphlets or flyers identifying some common species and sharing the "tidepooling etiquette" rules, that they can hand out. More shy students may want to simply hand these out, while more outgoing students can be enlisted to approach and talk to visitors.

Be sure to document this experience with photos and videos that can be shared with parents, the rest of the school - and perhaps even a local newspaper!

Alternatively, if a field trip isn't possible, have students simply create the informational pamphlets that you can hand out at the beach. You may want to contact State Parks to see if they would be willing to distribute the pamphlets as well.

Additional Resources

Tidepool Animals Poster or Printable

NOAA's Virtual Tidepool

Google Sites

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