SANDY BEACHES & ESTUARIES - COSEE · The ocean also brings live food to the sandy beach in the form of zooplankton and phytoplankton. Plankton is captured in the subtidal by filter

Sand Beach & Estuary 1

SANDY BEACHES& ESTUARIES

L e s s o n P l a n sA Curriculum in Marine Sciences

for Grades 4 - 8

UCLA OceanGLOBE


SANDY BEACH & ESTUARY LESSONS

A five page written background summary regarding Sandy Beaches and Estuaries by Dr. WilliamHamner, Ph.D., UCLA. May be duplicated for student reading material or as a subject contentbackground for teachers.

National Standards........................................................................9A page that lists the National Science Standards that apply to these Sandy Beach and Estuaryactivities.

Vocabulary....................................................................................10A single page that lists and defines 17 of the most important terms that relate to student under-standing of these Sandy Beach and Estuary activities.

Activity #1 - Sands of the World..................................................11A four-page activity in which students analyze samples of beach sand from all over the world anddeduce various things from the analysis including the possible geographic origin.

Activity #2 - Sand Tracks............................................................16A 6-page activity. Students learn to identify animals by the tracks the make on a sandy beach.

Activity #3 - Animals Between the Sand Grains..........................22A 6-page activity in which students conduct a laboratory analysis of the meiofauna: animals thatinhabit the interstitial spaces between sand grains.

Introduction to Sandy Beaches and Estuaries...............................3

California Science Standards.........................................................8A page that lists the California Science Standards that apply to these Sandy Beach and Estuaryactivities

Activity #4 - Hatching Brine Shrimp...........................................28A three-page lab. experiment in which subject brine shrimp eggs to a variety of environmentalconditions and measure the number of eggs that hatch over a period of time.

A 5-page activity in which students learn about estuaries by making a poster with the variety ofestuarine habitats on which pictures of organisms are pasted in the proper habitat.

Activity #5 - A Model Estuary......................................................32


Introduction to Sandy Beaches and Estuaries

BEACHES:

Storm waves refract, bending toward the rocky headlands, energy focused on the rocky intertidal,rolling rocks and crushing shells. The waves wash storm debris into inlets between the headlands, produc-ing beaches of pebbles and rounded stone. In turn, the pebbles break and fracture into smaller and smallerpieces, finally forming sand grains that pack uniformly along the beach. Sand fills the coves and estuaries,producing long flat sandy beaches, normal to the waves, that are resistant to the power of the swell andbreaking surf. During winter, the strong surf erodes these long flat beaches, fine-grained sands are movedoffshore into deeper water, and the beach becomes steep and coarse grained. Storms cut vertical berms intothe beach, marking the shoreward extent of the highest waves on the highest tide of the strongest storm. Inspring, the storms abate and the waves diminish. Gentle swash gradually returns fine sands to the beach. Insummer, the beach builds slowly seaward, and the beach slope becomes more gradual. Summer winds blowaway the winter berm and smooth the beach. This annual cycle of winter erosion and summer sand replace-ment is repeated, year after year.

Each year, more sand is carved from rocky headlands and new sand is moved toward the beach, but,also each year water currents transport sand, inexorably and directionally, along the beach until the sand isfinally lost far offshore. Waves refract as they approach the beach, bending into lines parallel to the shore,stirring up sand each time a wave crashes onto the beach. But although sand is resuspended each time awave breaks, this sand quickly settles directly back onto the bottom. Sand does not move directionallyalong the beach without a directional current. Directional currents parallel to the beach are called longshorecurrents, and they are caused by the wind. Because each and every beach is uniquely situated topographi-cally with respect to local winds, over the course of any given year these winds summate to produce a grand,long-term average force that drives the water next to the beach either up or down the shore. Theselongshore currents transport sand sideways along the beach, in step-wise fashion, each time a breaking wavesuspends the sand. Each year, therefore, new sand accumulates while old sand is floated away, and althoughwe view the beach as remaining much the same year after year, we do not see the same sand in the sameplaces at the same times of year. The beach is a very slow river of sand, in dynamic balance between theforces of erosion and deposition and the forces of resuspension and longshore transport

Because sandy beaches are always physically in flux, there are no permanent communities of inter-tidal plants growing on sandy beaches. Energy for the animals that inhabit sandy beaches is all imported,mostly from the sea. Soon after winter storms have ravaged offshore kelp beds, seaweed of all types driftsashore to molder and rot and enrich the sands. Beach amphipods and isopods accumulate near and belowthe piles of beach wrack and feed on the windfall, feeding at night but burying deep within the sand duringthe day to hide from the hoards of shore birds that probe and dig for crustacean prey. On tropical sandybeaches ghost crabs emerge from their burrows at night, racing up and down the beach in search of food.Dead fish and marine mammals wash ashore, to be slowly eaten from below by the scavengers of the beach.Terrestrial nocturnal scavengers, such as coyotes, mink, hyenas, and rats, compete with scavenging birds, thevultures, seagulls and eagles, for carrion.

The ocean also brings live food to the sandy beach in the form of zooplankton and phytoplankton.Plankton is captured in the subtidal by filter feeders and suspension feeding invertebrates, like mole crabsand surf clams. Enormous populations of these animals often occur along the beach, but their populationsare tightly zoned in relationship to the height of the tide. This is because they capture food most effectivelywhere the sand and the organic particles trapped within the sand are resuspended by breaking waves. On


gently sloping beaches with large tidal ranges, the location where the waves actually break moves towardand away from the shore, twice a day, as the tides rise and fall. In order to maximize feeding effectiveness,the mole crabs and the surf clams must follow the tides, migrating up the beach slope during rising tides anddown into deeper water when the tide begins to fall. These tidal migratory movements are so well ingrainedphysiologically that the animals continue to exhibit incipient rhythmical migratory movements even whenthey are in laboratory aquariums. When the sounds of breaking waves are played back to surf clams in thelaboratory, the clams jump out of the sand, and wait for the next wave!

Decay of beach wrack and entrapment of plankton by shifting sands enriches the interstitial watersaround the grains of sand with tiny particles of food. This food is exploited by large numbers of bacteriaand protozoa, but it is also exploited by one of the most unusual assemblages of animals in the sea, themeiofauna. This group of animals includes many species of multicellular metazoans from a large number ofphyla, all of which are very small, mostly less than 1 mm in length, so they can move about in the intersticesamong the grains of sand. Meiofaunal animals are not only very small, they are also long, thin, flat, andmobile, with reinforced body walls to resist crushing when the sand moves. They all exhibit reduction ofcomplex organs, including sense organs, but most have suckers or hooks for holding onto the sand when itshifts. Although many meiofaunal animals superficially look alike, there are meiofaunal cnidarians, mol-lusks, echinoderms, annelids, crustaceans, gastrotrichs, tardigrades, rotifers, nematodes, flatworms, andbrachiopods. Meiofauna are not only small, they are also difficult to extract from the sand. Although we donot know much about meiofauna, they are marvelous, miniature creatures.

A short essay on why sandy beaches are not all the same:Sandy beaches occur between the headlands of rocky coasts and also near estuaries and river mouths,

but these two types of sandy beaches are quite different because of the presence or absence of mud. Finegrained sediments, mostly silts and clays (mud), are delivered to the sea in huge quantities by large riverswhereas the weathering processes that occur on rocky headlands produce mostly produce gravel and sandsand almost no fine grained sediments. Consequently, beaches along the outer coast are composed primarilyof large grained sands of quite uniform size, fully oxygenated with depth, whereas coarse grained sands onbeaches near river mouths occur only very close to the surface, and the sand grades quickly with depth toanoxic silt and clay.

Sand grains on outer beaches pack together like spheres of uniform size, with a large amount ofspace, water, oxygen, and meiofaunal animals in the interstices between the sand grains. Meiofauna arefound primarily in medium to fine grained sands, with grain sizes of about 0.2 mm diameter supporting thelargest biomass of meiofauna. Because the sand grains in the intertidal zone of outer coast beaches are quiteuniform, they are constantly, albeit slowly, in motion, stirred by the waves and by the burrowing activities ofanimals.

Sandy beaches near estuaries, however, are similar to beaches along outer shores only near thesurface. When one digs below the surface of these beaches one quickly encounters very fined grained sandscomposed of silt and clay of mixed grain sizes, packed solidly together with almost no free space betweenthe particles. With little free space between the grains of sediment, there is not much space or water. In-stead of oxygen there is hydrogen sulfide gas that smells like rotting eggs.. Sediments with grain sizessmaller than 0.1 mm contain almost no meiofaunal animals. There are large burrowing animals on thesebeaches, however. Burrowing shrimp, crabs and worms, live in deep permanent burrow systems that areirrigated and oxygenated through permanent connections to the surface. Burrowing clams deep beneath thesurface extend their siphons to the overlying water, often through anoxic sediments, to bring down food andoxygen.

Grain sizes for particles and unconsolidated sediments found on beaches:


PARTICLES SIZEBoulders larger than 256 mmCobbles larger than 64 mmPebbles larger than 4 mmGranules larger than 2 mmCoarse Sand larger than 0.5 mmMedium Sand larger than 0.25 mmFine Sand larger than 0.06 mmSilt larger than 0.004 mmClay less than 0.004 mm

ESTUARIES:

Estuaries occur in quiet, partly enclosed coastal regions where rivers meet the sea. The uniquephysical and chemical attributes of estuaries relate primarily to the large volumes of fresh water and sedi-ments delivered to the sea by rivers. The mixing zone for fresh water and seawater within the estuary can beexceptionally complex, affected by the volume and rate of discharge of fresh water from the river, theamount and grain size of sediments in the river, the topography of the coastline, the tidal range, and thestrength and direction of prevailing wind and waves. Fortunately, this almost hopelessly bewildering arrayof factors becomes simplified in reality. There are actually only four major types of estuaries in the world,relating to geological forces that have been operating over thousands of years to produce quiet water coastalhabitats.

The 4 types of estuaries are:

1. Drowned River Valleys:Drowned river valleys, formed when sea level rose some 120 meters (about 400 feet) at the end of thelast ice age, some 18,000 years ago, are common along the east coast. The two largest drowned rivervalleys in the US are Chesapeake Bay and Delaware Bay.

2. Tectonic Estuaries:Tectonic estuaries were created geologically, not by rising sea level, but by subsidence of the land. Onthe west coast all of San Francisco Bay is now an estuary. The Golden Gate Bridge lies almost exactlyon top of the San Andreas fault, marking the boundary between the Pacific Plate and the North AmericanPlate. At this site the Pacific Plate is moving quite rapidly to the north, whereas the North AmericanPlate has subsided somewhat, filling with seawater from the sea and with fresh water from the Sacra-mento River.

3. Sand Bar or Barrier Island Estuaries:Barrier islands are a conspicuous feature along the east coast and the Gulf coast but not the west coast ofthe continental United States. Barrier islands were originally ancient beaches on the wide, gentle slop-ing continental shelves of the Atlantic and Caribbean when sea level began to rise 18,000 years ago.Pounding waves piled sand onto these shorelines, and, as sea level continued to rise, more sand washeaped on top of the dunes until a relatively stable barrier island was formed. But sea level continued torise, year after year for 18,000 years. Each year a bit more of the front of the barrier island was erodedaway by waves and each year more sand blew across the dunes to be deposited in the lagoon behind theisland. These processes continue today, and each year barrier islands move a bit closer to the mainland.Barrier islands isolate barrier lagoons from the sea. Rivers discharge into these lagoons, and near the


river mouths barrier lagoons are true estuaries, full of brackish water, mud and silt. Similar sorts ofbarrier islands were not formed on the Pacific Coast because the continental shelf there is too narrowand steep for sand bar beaches.

4. Fjords: Fjords are deep valleys that were cut by glaciers during the last glaciation, but that now are supplied with

sea water from one end and fresh water at the other. There are no fjords in the continental United States, butfjords are common in Alaska, Canada, Chile, New Zealand, and Norway. A fjord is often separated from thesea by a shallow sill at the mouth, formed of rocks that were pushed ahead of the actively moving glacier.Now the only remnant of the glacier is a wall of mostly submerged rocks across the mouth of the water-filled valley.

Estuaries are physically structured by the geological processes that produced the estuary, but they are alsostructured by forces that affect the delta at the mouth of the estuary, forces generated by waves, tides, and theriver itself.

1. Wave dominated estuaries often have a sand bar or sand spit across the mouth of the estuary. This sandbar breaks the force of the waves and physically protects the estuarine lagoon from wind and waves.These sand bars form even if the wave regimen is exceptionally strong because waves are wind drivenand because the wind almost never blows directly at right angles, or normal, to the shore. Consequently,once breaking waves have suspended the sand, the longshore current driven by the wind moves the sandin stepwise fashion down the beach and across the mouth of the river. Tidal currents and river dischargemaintain an opening to the estuarine lagoon, but this opening is always downwind of the river, neverdirectly opposite the river mouth.

2. Tide dominated estuaries are open directly to the ocean; they have no sand bar across the river mouth.Tide dominated estuaries occur where there is an exceptionally high tidal range so that during flood andebb tides large amounts of sea water race up and down the mouth of the river. These strong tidal currentsprevent the development of a protective sand bar across the mouth of the river.

3. River dominated deltas are river systems little influenced by the ocean. Here the river is so strong thatfreshwater discharge creates a huge fan-shaped offshore delta of muddy deposits, with relatively littleincursion of sea water. The Mississippi River delta is such a system. When upstream dams restrict theflow of water and sediments out of these rivers, however, then saltwater incursions do occur, often withunexpected consequences.

These hydrodynamic distinctions among types of estuaries are exceptionally important. Wave domi-nated estuaries are protected by an offshore sand bar, so they accumulate sediments and exhibit strong waterstratification because of the absence of waves in the lagoon. Most storms do not have a major impact waveon these estuaries because the sand bar in front of the river protects the estuary from all but the strongestwaves. Tide dominated estuaries, on the other hand, are always exposed to waves, sediment accumulation islow, and tidal currents force the sea far inland. During storms, storm surges as high as 5 m (16.5 ft) abovenormal high water race inland, unimpeded by a protective sand bar, and inland damage from storm surgewaters is often disastrous. For example, the nation of Bangladesh is dominated by the Ganges-BrahmaputraRiver delta, a tide dominated delta. Tropical cyclones in the Bay of Bengal regularly produce storm surgesthat cause catastrophic damage to the delta. In 1970, 300,000 people in Bangladesh were killed by stormdamage, and another 140,000 were killed in 1991.

The dynamic forces within estuaries of waves, tides, and rivers and the shifting substrate of silts and


clays produce an exceptionally difficult set of environmental conditions for the establishment of plant andanimal populations. Animals and plants that inhabit estuaries must be able to live in an aquatic environmentwhere they might be adjusted physiologically to fresh water, only to be abruptly immersed in full strengthseawater. Very few aquatic organisms can tolerate such extreme rapid changes in salinity. The result is thatthe number of species of plants and animals that inhabit estuaries is low. However, populations of thespecies that can live in estuaries are often exceptionally large because rivers wash huge quantities of nutri-ents (such as nitrogen, phosphorous, silicate, and iron) out of terrestrial soils. The rivers quickly transportthese nutrients to the estuary, where they are intercepted primarily by marsh grasses and sea grasses, promot-ing rapid and high primary productivity along the shore. In turn, this new production of plant tissue supportslarge populations of estuarine invertebrates, zooplankton, and fish. Estuaries are particularly importantlocations for the development of coastal fish populations because of the high productivity. In addition, theshallow water, the structural complexity of the benthic plants and the high turbidity produced by muddywater provides protection for larval fish from predators.


CONCEPTS RELATED TO THECALIFORNIA STATE SCIENCE STANDARDS

Grade 4 - Life SciencesAll organisms need energy and matter to live and grow. As a basis for understanding this concept:

a. Students know plants are the primary source of matter and energy entering most food chains.

b. Students know producers and consumers (herbivores, carnivores, omnivores, and decomposers) arerelated in food chains and food webs and may compete with each other for resources in an ecosystem.

c. Students know decomposers, including many fungi, insects, and microorganisms, recycle matter fromdead plants and animals.

Grade 6 - Life SciencesOrganisms in ecosystems exchange energy and nutrients among themselves and with the environment. As abasis for understanding this concept:

a. Students know energy entering ecosystems as sunlight is transferred by producers into chemical energythrough photosynthesis and then from organism to organism through food webs.

d. Students know different kinds of organisms may play similar ecological roles in similar biomes.

e. Students know the number and types of organisms an ecosystem can support depends on the resourcesavailable and on abiotic factors, such as quantities of light and water, a range of temperatures, and soilcomposition

All Grades:Investigation and Experimentation

Scientific progress is made by asking meaningful questions and conducting careful investigations. As abasis for understanding this concept and addressing the content in the other three strands, students shoulddevelop their own questions and perform investigations. Students will:

1. Develop a hypothesis.

2. Select and use appropriate tools and technology (including calculators, computers, balances, springscales, microscopes, and binoculars) to perform tests, collect data, and display data.

3. Construct appropriate graphs from data and develop qualitative statements about the relationships be-tween variables.

4. Communicate the steps and results from an investigation in written reports and oral presentations.

5. Recognize whether evidence is consistent with a proposed explanation.

6. Interpret events by sequence and time from natural phenomena.

7. Identify changes in natural phenomena over time without manipulating the phenomena.


CONCEPTS RELATED TO THENATIONAL SCIENCE STANDARDS

POPULATIONS AND ECOSYSTEMS· A population consists of all individuals of a species that occur together at a given place and time. All

populations living together and the physical factors with which they interact compose an ecosystem.· Populations of organisms can be categorized by the function they serve in an ecosystem. Plants and

some micro-organisms are producers—they make their own food. All animals, including humans, areconsumers, which obtain food by eating other organisms. Decomposers, primarily bacteria and fungi,are consumers that use waste materials and dead organisms for food. Food webs identify the relation-ships among producers, consumers, and decomposers in an ecosystem.

· For ecosystems, the major source of energy is sunlight. Energy entering ecosystems as sunlight istransferred by producers into chemical energy through photosynthesis. That energy then passes fromorganism to organism in food webs.

· The number of organisms an ecosystem can support depends on the resources available and abioticfactors, such as quantity of light and water, range of temperatures, and soil composition. Givenadequate biotic and abiotic resources and no disease or predators, populations (including humans)increase at rapid rates. Lack of resources and other factors, such as predation and climate, limit thegrowth of populations in specific niches in the ecosystem.

SCIENTIFIC INQUIRY· Different kinds of questions suggest different kinds of scientific investigations. Some investigations

involve observing and describing objects, organisms, or events; some involve collecting specimens;some involve experiments; some involve seeking more information; some involve discovery of newobjects and phenomena; and some involve making models.

· Current scientific knowledge and understanding guide scientific investigations. Different scientificdomains employ different methods, core theories, and standards to advance scientific knowledge andunderstanding.

· Mathematics is important in all aspects of scientific inquiry.· Technology used to gather data enhances accuracy and allows scientists to analyze and quantify

results of investigations.· Scientific explanations emphasize evidence, have logically consistent arguments, and use scientific

principles, models, and theories. The scientific community accepts and uses such explanations untildisplaced by better scientific ones. When such displacement occurs, science advances.

· Science advances through legitimate skepticism. Asking questions and querying other scientists’explanations is part of scientific inquiry. Scientists evaluate the explanations proposed by otherscientists by examining evidence, comparing evidence, identifying faulty reasoning, pointing outstatements that go beyond the evidence, and suggesting alternative explanations for the same obser-vations.

· Scientific investigations sometimes result in new ideas and phenomena for study, generate newmethods or procedures for an investigation, or develop new technologies to improve the collection ofdata. All of these results can lead to new investigations.


SANDY BEACH & ESTUARY VOCABULARY

brackish slightly salty

deposit feeder organism that eats debris from the sand

detritus organic matter nutrients from decomposing plants and animals

estuary where fresh water meets seawater

meiofauna microscopic animals that live between grains of sand

mudflat soil exposed at low tides, with no visible vegetation, but with living organismsbelow the surface

open water the flowing fresh, brackish and salt water away from shore

salt marsh grassy area of an estuary

sandy beach beach next to the ocean

suspension feeder organism that filters tiny plankton from the waves

uplands highest elevation in an estuary

wetlands areas that periodically have waterlogged soils

.


Activity #1 - Beach Sands of the World

Objective:Students will observe sand samples and then find the possible origins of the sand on a world map by plottingthe latitude and longitude.

Materials:· sand samples · vinegar· magnets · metric ruler· world maps for each student · petri dishes· large world map for class, or a world map projected· microscopes, or hand lenses · scotch tape· scissors · data sheet· 3x5 index cards

Procedures:1) Obtain sand samples from all over the world (through travel, swapping, friends etc). Look up the ap-

proximate latitude and longitude for each sample and make a note of it. Assign a random letter of thealphabet to each team of students. The number of teams is determined by the number of different sandsamples you have, teams of two would be ideal.

2) Each team of students will obtain a 3x5 index card. The card if folded in half lengthwise, and a V-shaped notch is cut in the middle of the fold so a diamond hole in the middle results when the card isunfolded.

3) Students then stick a piece of scotch tape across the hole and turn the card so the sticky side is facing up.The team obtains one of the teachers sand samples A small pinch or sprinkle of sand grains are spreadacross the sticky tape and pressed gently to make them adhere. Students should write their alphabeticteam designation on the card.

4) Next, have the team complete a data record for their sand sample considering the following:a. Color. Record the most obvious color and the other colors of the sand grains in your sampleb. Length*: Estimate the length of the smaller and large sand grains; compute the average size in

mm. (*Advanced students can compute a nearly exact length using a microscope whose field diameter isknown. The number of sand grains that would “fit” this diameter is estimated, then divided into the fielddiameter to calculate the length of one sand grain).

c. Particle name: Based on the size range, tell name?d. Shape: Round, oval, square, rectangular, triangular?e. Rounding: Are the corners sharp or rounded?f. Surface Texture: smooth or rough?

5) An extended analysis can be done if you have a larger supply of each sand sample:g. Magnetism: Is there a large, medium or small amount of material attracted to a magnet?h. Quartz (SiO2) or Calcite (CaCO3): Place a drop of dilute vinegar on each sample and see if any

grains fizz. Use your hand lens and note which grains react with acid.

6) When all the data charts have been completed, arrange your class into larger groups according to the


most obvious color of their sand sample. Have each team write their alphabetic team letter on the worldmap by matching the latitude and longitude coordinates they were given.

Discussion:7) Are there any noticeable global patterns of distribution of sand by color? Explain.8) Are there any noticeable global patterns of distribution of sand by any other features? Explain.9) Give each large group an “unknown” sand sample that is the same as their unique color.Ask the group to perform an analysis of the unknown sample and to discuss theese data among themselves.

a) Can the origin of this unknown sample be determined by comparing it to the team data?b) Which characteristics were most useful in identifying the unknown sample?c) What other kinds of data (that we did not collect in our study) might also be helpful?


Activity #1 - Beach Sands of the WorldSAMPLE 3X5 SPECIMEN CARDS

CLOSE UP VIEWof SAND IN CENTER

CLOSE UP VIEW ofSAND IN CENTER


Student name__________________________________________________________

Team Members ________________________________________________________

Sand Sample Letter Code ______

Latitude____________________________ Longitude__________________________

DATA OBSERVATIONS:

a. Color: Main Color:_____________ Other Colors:______________________________

b. Length Smallest:____________ Largest:_________________ Average:__________________

c. Particle name: _______________________________

d. Shape: _______________________________

e. Rounding: _______________________________

f. Surface Texture: _______________________________

g. Magnetism: _______________________________

h. Quartz (SiO2) or Calcite (CaCO3): _______________________________

DRAW A DIAGRAM OR SKETCH OF YOUR SAND GRAINS. (Label by pointing out the features yourecorded above)

Activity #1 - Beach Sands of the WorldSAND GRAIN DATA SHEET


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Activity #2 - Sand Tracks

Objective:Students match animal tracks made in the sand by guessing who made them.

Materials:· Animal track cards· Animal pictures· Guessing sheet

Procedures:1. The teacher makes copies of track cards and animal cards on 8 ½ x 11 poster board.2. As the teacher holds up track cards the students guess which animal made it and why they think so.3. After the students have written down their guesses and reasons for their choices, hold up pictures in

random order of the animals that made the tracks. Have students write next to their guesses the name ofthe animal they now believe made the tracks.

4. Show students the correct choices.

· If available, sand casts can be made of prints by using plaster of paris in a ring surrounding a foundtrack.

Discussion:A. What clues from the tracks led you to suspect the identity of the animals?B. How can scientists use the location of tracks in their study of specific beaches? (To record the predators

and prey found in specific areas for population studies.)


SKUNK

Activity #2 - Sand Tracks(image courtesy of Missouri Department of Conservation)

RABBIT


FOX


COYOTE


DOMESTIC CAT


BOBCAT



GULL

HUMAN



HERON

CORMORANT


Objective:Students will observe the minute animals that live between sand grains.

Materials:· plastic tray· turkey baster or large pipette· microscope· petri dish

Procedures:1) Collect meiofauna samples from the surface of the sand at low tide in low wave action areas. Scrape a

layer about 1 cm deep into a plastic tray. Add some seawater from the same location, enough to justbarely cover the sand sample and form a pool on top about 1/2-inch deep at the most.

2) Allow the specimen trays to stand at room temperature, undisturbed, for approximately a week, or untilthere is just a small amount of visible seawater left on the surface of the sand. As the sand sits for aweek the environment beneath the sand starts to suffer from oxygen depletion and the meiofauna willcrawl up out of the sand to reach the upper, oxygenated water above the sand.

3) Technically, the meiofauna consists of small benthic metazoans that pass through a 0.500 mm sieve andare retained on a 0.045 mm sieve. Thus, the next step is to gently remove the seawater (pour it withoutalso pouring the sand, or use a large pipette such as a turkey baster) from the surface of the sand andstrain it through a fine mesh material, such as a piece of an old nylon stocking.

8) Rinse the collected organisms from the mesh and observe the small animals in the petri dish under themicroscope.

Discussion:A· Sketch the organisms, paying attention to appendagesB· How many different animals were found?C· Why were no plants found in this environment?D· Can the phylum be identified for each animal? List the phyla.E· Which phyla were the majority?F· How do you think the meiofauna animals feed, based on their appendages?

Activity #3 - Animals Betweenthe Sand Grains - Meiofauna


Phyla or Group

GastrotrichichaXenotrichula, Turbaanella, Pleurodasys, Pseudostomella, Tetranchyroderma

Crustacea/Ostracoda (6 unknown species)

Crustacea/Copepoda/HarpacticoideaArenostella kaiseri, Arenopontia dillonbechia, Ameria parvuloides, Apodopsyllus vermiculiformes, unident.Paramesochiridae

NematodaEnoploidea, Desmodoridea, Monohyssterioidea, Chromadoroidea, Draconematoidea (Epsilonema)

TurbellariaAcoela, Rhabdocoela (Typhloplanoida & Kalyptorhynchia), Alleocoela

NemertinaOtotyphlonemertes, Procephalotrix

ArchiannelidaSaccocirrus gabriellae, Protodriloides chaetifer

PolychaetaPisione remota, Hesionides arenaria, Microphthalmus, Petitia amphophthalama, Hesioneura, Glycera,Stygocapitella subterranea

OligochaetaTubificidae, Enchytraeidae (Marionina)


REFERENCE LIST OF SPECIES AND THEIR PHYLAMeiofauna of Moss Landing Beach, Moss Landing, CA. From Narine 1976.

source: Monterey Bay National Marine Sanctuary, http://bonita.mbnms.nos.noaa.gov


NEMATODE: ROUNDWORM

POLYCHAETE: Eusyllis sp. SEGMENTED WORM


Images from Humboldt County, California. courtesy of Matthew Hooge, University of Maine http://hooge.developmentalbiology.com/meiofauna/


TARDIGRADE: WATER BEAR

GASTROTRICH: Turbanella mustella




CRUSTACEA: HARPACTICOID COPEPOD

CRUSTACEA: OSTRACOD






CRUSTACEA - ISOPODA: Microcerberus abbott


Activity #4 - Hatching Brine Shrimp

Objective:Students experiment with temperature and salinity to detect favorable environments for hatching brineshrimp eggs.

Materials:· 6 small clear jars or beakers with covers/lids (for each group of students)· magnifying glass or low power microscope· eye droppers· 30g non-iodized salt, NaCl, or sea salt· brine shrimp eggs· refrigerator· lamp· 10% salt solution· ocean water (3.0 - 3.5% salt)· fresh water· data sheet

Procedures:1) Mix the 10% salt solution by adding 10g of NaCl, sea salt or non-iodized salt to each 1 liter of fresh

water.2) Have groups of students set up their 6 jars as described below. Add about 50 brine shrimp eggs to each

jar.Temperature experiment: (3 jars)

Jar 1 3/4 jar of seawater, add eggs and place in refrigeratorJar 2 3/4 jar of seawater, add eggs and place at room temperatureJar 3 3/4 jar of seawater, add eggs and place close to light bulb, but not too close

Salinity experiment: (3 jars)Jar 4 3/4 jar of fresh water, add eggs and place at room temperatureJar 5 3/4 jar of seawater, add eggs and place at room temperatureJar 6 3/4 jar of 10% salt solution, add eggs and place at room temperature

3) Make some predictions about which environments will yield the most hatched brine shrimp.

4) On your data chart, record the number of hatched brine shrimp each day by carefully observing each jar.


Activity #4 - Hatching Brine Shrimp

Discussion:

A- Did the temperature at which the eggs were kept have an effect on the number that hatched? Why?B- Which salinity solution gave the best hatching results? Why?C- Does pollution have an effect on the number of hatching eggs? Explain.D- Explain another experiment you could perform, using the information you learned the first time, toobtain higher levels of hatching of brine shrimp


Activity #4 - Hatching Brine ShrimpSIMPLIFIED DIAGRAM OF Artemia, THE BRINE SHRIMP


Activity #4 - Hatching Brine ShrimpSTUDENT DATA CHART

TEM

PER

ATU

RE

SALI

NIT

YEX

PER

IMEN

TEX

PER

IMEN

T

NU

MBE

RJA

R N

UM

BER

JAR

NU

MBE

RH

ATC

HED

12

34

56

D

AY

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15


Activity #5 - A Model Estuary

Objective :Students will assemble a poster of an estuary showing the five communities of animals and plants thatinhabit the estuary.

Materials:· glue· pictures of estuarine organisms (next pages)· scissors· colored pencils, pens, watercolor· butcher paper or poster board

Procedures:1) Have students research the concept of an estuary: a meeting of fresh water, ocean water and land.2) Students will find photographs or diagrams of various estuaries to identify and see the differences

between the 5 distinct communities that inhabit an estuarine environment:· open ocean· sand beach/sand bar· tidal marsh· mud flats· estuary uplands

3) Students begin their poster project by making an estuary background that depicts each of the 5 distinctcommunities. They may paint, draw or cut magazine photographs to make this background. Encouragethem to show the underwater environment too (for open ocean species and fish).

4) Cut and paste the pictures of estuarine organisms (next pages) in their proper community.

Discussion:Have students write an explanation of each community found in the estuary. Have them include the type ofanimals and vegetation found there.


Activity #5 - A Model EstuaryIllustrations used with permission of Padilla Bay National Estuarine Research Reserve

http://www.padillabay.gov/

PIPEFISH

GHOST SHRIMP

BARNACLE

CANCER CRAB

DUCK




EAGLE

FLATFISH

GULL

GUNNEL

HERMIT CRAB

HERON




MUD SNAIL

KILIFISH

MUSSEL

OCHRE STAR

PIPEFISH

PLANKTON




POLYCHAETE WORM

EEL GRASS

SUN STAR

SURFPERCH

SCULPIN

SHORE CRAB

Documents

SANDY BEACHES & ESTUARIES - COSEE · The ocean also brings live food to the sandy beach in the form of zooplankton and phytoplankton. Plankton is captured in the subtidal by filter