y a B e k a e p a s Chesapeake Bay Theme Day e Traveling Outreach Program Pre- and Post-Visit Activities h Grades 3-4 C Education Department 501 East Pratt Street Baltimore, MD 21202 Reproduction for educational purposes only. Printed on recycled paper, preserving aquatic habitats. 12/13 The National Aquarium is a nonprofit organization whose mission is to inspire conservation of the world’s aquatic treasures. 501 East Pratt Street • Baltimore, MD 21202 aqua.org This booklet was prepared by the Education Department at the National Aquarium. Illustration: Cindy Belcher The educational goals of the National Aquarium are supported by funding from the Jacob and Hilda Blaustein Aquatic Education Endowment Fund. The booklet may be reproduced by any teacher, school or school district for educational purposes. © 2010 Chesapeake Bay Theme Day Auditorium programs and 20-minute lab sessions for Grades K-6 A school-wide package is a great way to give classes in multiple PLANNING FOR THE OUTREACH PROGRAM grade levels (K-6) the opportunity to benefit from a traveling This lesson includes pre- and post-program activities that will outreach program. Each package includes: supplement the auditorium program and discovery lab sessions. These activities can be incorporated into science, reading and • Two auditorium presentations (one for grades K-2 and social studies units about Maryland, the Chesapeake Bay, map one for grades 3-6) studies or ecology lessons. This lesson should be covered in • Ten interactive discovery sessions that allow students to three days including the outreach program at your school. explore the theme in depth and to investigate animals introduced in the auditorium presentation. Each 20-minute session is identical and is limited to one class (of up to 30 students maximum) to allow for optimal AAAS Benchmarks learning. Parent volunteers are required to assist with interactive discovery sessions. See Parent Volunteer 5D/E4-3-5: Changes in an organism’s habitat are Instructions on page 2 for more information. sometimes beneficial to it and sometimes harmful. 12D/E7-3-5: Write a clear and accurate description OUTREACH PROGRAM DESCRIPTION of a real world object or event. Marshland Mystery Auditorium Presentation Grades K-2 (35 minutes) MD Voluntary Curriculum: Science What animals can you find in the marsh and what is happening to them? Investigate the animals of a marsh, how they live and the challenges they face. Grade 3 - 1.0 Skills and Processes B.1.a Develop explanations possessed and evidence from The Waterman Auditorium Presentation observations, reliable print sources and investigations. Grades 3-6 (60 minutes) Grade 3 - 6.0 Environmental Science A.1. Explore the Chesapeake Bay through the experiences of a Use scientific skills and processes to explain the interac- waterman. Costumes, artifacts and personal stories help tions of environmental factors (living and non-living) and students understand how the loss of habitat affects both analyze their impact from a local to a global perspective. animals and people. Grade 4 - 3.0 Life Science F.1. Discovery Labs Explain ways that individual and groups of organisms Examine the Chesapeake Bay through artifacts, basic interact with each other and the environment. science experiments and live animals. (Live animals are subject to availability.) Grade 4 - 6.0 Environmental Science B.1. Recognize and describe that people in Maryland depend on, change and are affected by the environment. Chesapeake Bay Theme Day – Grades 3-4 1 DAY 1: PRE-OUTREACH PROGRAM ACTIVITIES Before educators from the National Aquarium’s Outreach Department visit your school, read the Teacher Background section found on pages 4-7 and share with your students. As a class, complete Activity 1 – Making Tracks on pages 14-15 and Activity 2 – Oysters and Blue Crabs of the Chesapeake Bay found on pages 19-22. These activities will allow students to familiarize themselves with vocabulary and material that will be taught during the Aquarium programs as well as reinforce what the students already know about the Chesapeake Bay. These activities incorporate content areas touched upon during the National Aquarium’s outreach program including information about the Chesapeake Bay watershed, animals found in the Chesa- peake Bay and current events associated with health of the Chesapeake Bay. DAY 2: OUTREACH PROGRAM AT YOUR SCHOOL 3. Lab sessions are 20 minutes each in duration. Each session is identical. On the day of your outreach program, the National Aquarium outreach staff will present two large-group auditorium 4. Parent volunteers are required for the lab sessions. See programs—one for grades K-2 (35 minutes) and one for below for instructions. Grades 3-6 (60 minutes). Ten to twelve discovery lab sessions 5. National Aquarium outreach staff will need a copy of (depending upon what is written on the contract) will take the schedule upon arrival. place in a separate room throughout the school day. See sample schedule on page 3. Parent Volunteer Instructions: Auditorium Presentation Requirements: 1. Parent volunteers need to arrive approximately 30 minutes prior to the start time of the first lab session for training. 1. One room large enough to hold all of the students (Some parents may only be able to stay for part of the scheduled to attend that presentation. day. You may wish to plan for one morning set of vol- 2. Students should be seated and ready to begin at the unteers and one afternoon set. The afternoon set should start time listed on the contract. arrive 30 minutes prior to the afternoon’s first lab session.) 3. Allow 35 minutes for the K-2 presentation and 60 2. Each parent volunteer will be in charge of one station minutes for the Grades 3-6 presentation. during the entire Discovery Lab session. 3. The parent volunteers’ main task will be to guide the students through the assigned station and actively Discovery Lab Session Requirements: engage students with questions and fun facts. 1. Labs need to be in one room for the entire day. The room 4. Useful questions include: “Why is a marsh a great needs to contain four large tables (or desks that can be habitat for animals?,” “How do watermen catch blue pushed together), a power outlet and, if possible, a sink. crabs?” or “Why might an animal have a shell?” Object 2. Each individual class will come to this room approximately comparisons are also useful (ex. find similarities, two minutes before their scheduled time. Teachers should differences, etc.). have the class divided into four groups. 5. Please focus the students’ attention back on the National Aquarium instructor when it is time to rotate to the next station. Chesapeake Bay Theme Day – Grades 3-4 2 SAMPLE SCHEDULE The outreach staff at the National Aquarium is happy to review your schedule to ensure that the program will run smoothly. Please send a copy of your schedule via fax to 410-659-0116 Attn: Outreach or e-mail [email protected]. AUDITORIUM PROGRAM DISCOVERY LABS Time Program Time Program 9-10 a.m. Grades K-2 9-9:30 a.m. Aquarium staff will also set (extra time allotted for transition and up labs during the morning set-up for the next program) presentation 10-11 a.m. Grades 3-6 9:30-10 a.m. Train morning set of volunteers 10-10:20 a.m. Grade 1 10:25-10:45 a.m. Grade 1 10:50-11:10 a.m. Grade 2 11:15-11:35 a.m. Grade 2 11:40 a.m.-12 p.m. Grade 3 Lunch, rest animals, train 12-1 p.m. afternoon volunteers 1-1:20 p.m. Grade 3 1:25-1:45 p.m. Grade 4 1:50- 2:10 p.m. Grade 4 2:15-2:35 p.m. Grade 5 2:40-3 p.m. Grade 5 DAY 3: POST-OUTREACH PROGRAM ACTIVITIES The day after the outreach program, complete Activity 3 – Bayscaping: Building an Environmentally Friendly Yard found on pages 25 -26. This activity highlights current issues facing the Chesapeake Bay and conservation actions that can be taken to help. This activity also reinforces what students learned from the Aquarium’s presentation and discovery lab. Chesapeake Bay Theme Day – Grades 3-4 3 HABITATS OF THE BAY A habitat describes the place where a particular species lives and contains the necessary food, water, shelter and space needed for an organism to survive. Three important habitats found in the Chesapeake Bay are SAV beds, oyster reefs and marshes. In the shallow water of the Chesapeake Bay, underwater grasses—or submerged aquatic vegetation (SAV)—provide food and habitat for many fish, invertebrates and migratory birds. Blue crabs hide within the underwater grass beds after molting when their soft “shells” are most vulnerable to predators. Molting is the process by which crabs shed their outer covering Chesapeake Bay Watershed (called an exoskeleton) in order to grow. Small fish find refuge from larger predators among the grass beds. SAV beds act as a nursery for crabs and fish, including menhaden, herring and shad. Bay grasses are also a valuable food source for mi- grating and resident bird species. Underwater grasses are im- portant primary producers in the Bay, adding oxygen to the water through photosynthesis. They improve the Bay’s water Teacher Background quality by absorbing excess nutrients. SAV beds also reduce wave action that can erode shorelines and trap sediment that THE CHESAPEAKE BAY would otherwise cloud the water. The Chesapeake Bay is about 200 miles long with an average depth of less than 25 feet (7.6 meters). The Bay itself lies Oyster reefs can be found throughout the mid to lower Bay. entirely within the states of Virginia and Maryland. However, These reefs, or bars, are formed when young oysters—called the water from rivers and streams that drains into the Bay spat—settle on the firm surfaces of mature or dead oyster (known as the watershed) comes from a much larger area. shells. The accumulation of oyster upon oyster results in the The Chesapeake Bay watershed covers over 64,000 square formation of clusters of oysters, which create refuges for small miles and includes parts of Maryland, Virginia, Pennsylvania, fish and invertebrates. The oyster shells offer a hard substrate New York, West Virginia, Delaware and Washington, DC. More where organisms such as barnacles, tunicates and sponges can than 16 million people live in the Chesapeake Bay watershed. attach. The natural ability of oysters to filter dirt from the water results in higher water clarity and light penetration in The Chesapeake Bay is one of this country’s greatest resources. these areas. Fish such as gobies, blennies and skilletfish live The Bay is home to many plants and animals that interact in in and among the oyster reef community. a complex ecosystem. Many species of fish that live in the ocean as adults spawn and mature in the Bay. In the winter Marshes are a type of wetland that contains mostly tall months, the Bay provides food and a much-needed resting grasses, with some flowers and small bushes. Marshes have a place for migrating birds and waterfowl. For centuries, humans natural supply of water—either from tides, flooding rivers or have reaped benefits from the Bay: we have eaten its animals, groundwater. Salt marshes are characterized by salt-tolerant used it for commerce and shipping and participated in recre- plants and animals, while freshwater marshes contain the more ational activities along its beautiful banks. The Bay is home to salt-sensitive species. Brackish marshes—marshes with one of the largest shipping centers on the East Coast, with salinities ranging between those of freshwater and saltwater— more than 90 million tons of cargo traveling its waters each are also marshes that are found along the Chesapeake Bay. In year. Millions of people head to the Bay every year to go boating, the Chesapeake Bay region, a tidal marsh experiences a change fishing, swimming or to enjoy some other water-related activity. in the water level four times each day with the changing tides— However, human pollution threatens to destroy the Bay’s value two high tides and two low tides. The part of the marsh that as a home for wildlife as well as a source of food and recreation. is often submerged by incoming tides is termed the low marsh. Chesapeake Bay Theme Day – Grades 3-4 4 Plants that are found in this area, including salt marsh cordgrass, can tolerate oxygen-poor mud and have adapted to being partially or completely submerged by the tides. The upper part of the marsh—termed the high marsh—receives less tidal action, usually only from exceptionally high tides. Wetlands play numerous environmental roles. They prevent erosion by binding to soil and blocking runoff. They act as a sponge by preventing flooding and absorbing pollutants before they can enter the Chesapeake Bay. They also provide a valuable habitat for nu- merous species of animals and plants. Wildlife, such as beavers, muskrats, songbirds and wading birds, depend on wetlands for food and shelter. Fish and crustaceans utilize wetlands as well. FEATURED ANIMALS IN THE BAY Oysters are mollusks, and are in the same phylum as octo- old one. However, the newly exposed exoskeleton will not fully puses, squid, clams and snails. They are bivalves, which harden for about three days. During this time, the soft-shell mean they have two shells held together by powerful adductor crab is extremely vulnerable to predators, and it will hide in muscles. The animal itself is a filter feeder, which means protected areas such as marshes and underwater grass beds. that the oyster draws in water through its gills and filters out phytoplankton, its food. Pollutants and sediments are also The great blue heron is one of the largest and most measures sucked into the oyster’s body. The oyster packages the up to 4 feet in height with a 6-foot wing span. Although many sediment into tiny pellets, which are then expelled from the herons migrate through the Chesapeake Bay region, some oyster to settle on the bottom of the Bay, thus purging them remain in the Bay area year-round. More than half of the from being suspended in the water column. An adult oyster Atlantic Coast breeding population of great blue herons nests can filter up to 60 gallons of water per day! in the Chesapeake Bay area. These water birds hunt silently by stalking small fish and swallowing them head first. They also Blue crabs are perhaps the most famed residents of the Ches- eat frogs, salamanders, lizards, snakes, crawfish, small birds, apeake Bay. The last pair of legs on the blue crab are modified rodents and insects. Great blue herons are one of the top into flattened paddles called “swimmerets” that assist the crabs predators of the Bay food chain. in locomotion. Indeed, the blue crab’s scientific name, Callinectes sapidus, literally means “beautiful swimmer that tastes good.” The common name “blue crab” stems from the brilliant blue FOOD CHAIN that mature males exhibit on the undersides of their claws. The The organisms in a food chain are placed into one of three blue crab is a crustacean and is related to lobsters, shrimp and groups based on how they meet their energy requirements. hermit crabs, among others. Like most large crustaceans, blue crabs have a hard exoskeleton (often referred to as a shell) made Producers make their own food using simple chemicals and of chitin and calcium. Because the exoskeleton does not grow energy from the sun. Green plants, underwater grasses with the crab, it must be shed and replaced periodically by a and microscopic phytoplankton are producers. new, larger outer skeleton. During this process, called molting, Consumers are animals that eat producers or other consumers. the old exoskeleton cracks just below the crab’s eyes and all A consumer that eats plant matter is called an herbivore the way to the points of the shell. The exoskeleton also cracks (ex. oyster); one that eats animal matter is called a carnivore along the backside and along the top of the claws. Once the (ex. great blue heron). A scavenger is a consumer that feeds exoskeleton is broken open, the crab backs out of it. The crab on dead animals (ex. blue crab). A consumer that eats both then draws in water, forcing its new soft exoskeleton to swell. plant and animal matter is called an omnivore. The new exoskeleton will be about one-third larger than the Chesapeake Bay Theme Day – Grades 3-4 5 Decomposers are organisms that break down dead plant or HARVESTING OYSTERS IN THE BAY animal material into simple chemicals. These simple chemicals When Europeans first encountered the Bay, they found are recycled when used by producers to make food. Bacteria abundant oysters throughout. Indeed, the Powhatan Native are the most important decomposers in the Bay. Americans aptly named the Bay “Chesepioc” which means “the Great Shellfish Bay.” These American oysters formed A food chain starts with a producer, such as, phytoplankton reefs so vast they posed a hazard to incoming ships. There (microscopic plants that drift with water currents). The phyto- were so many oysters that they could filter the entire Bay in plankton may be eaten by zooplankton (microscopic animals), a few days. Now, the same process takes over a year due to the second link in the food chain. The zooplankton may be increased sediment pollution and vastly lower numbers of eaten by a small fish like an Atlantic silverside, which may oysters found in the Bay. then be eaten by a larger fish like a bluefish. The zooplankton, silverside and bluefish are all primary, secondary and tertiary As early as the 1850s, New England oysters off the coasts of consumers, respectively. The bluefish in turn may be eaten by New York and New Jersey began to show signs of overharvesting. an osprey or another top predator. This is the fifth and final link Yankee watermen turned to the Chesapeake Bay for their in the food chain. Because the osprey is not eaten by any other harvest. With them they brought their latest innovation—the animal, they are called the top predators. Humans are also oyster dredge—and completely changed the Bay’s oyster fishery. often considered the top predator in a food chain. This is just Local watermen, who up until then had been dependent on one example of a food chain that exists in the Chesapeake Bay. the awkward, heavy oyster tongs for their oyster catch, began turning to the dredge. The dredge combined an iron rake, used to scrape oysters from other shells, with a metal bag used to collect the oysters. When combined with steam-powered ships, FOOD CHAIN this method of dragging the dredge behind the boat could be used in much deeper waters and resulted in a far greater catch than tonging. Dredging proved to be far more destructive to oyster bars as well. Maryland passed laws as early as 1865 in order to protect its valuable oyster beds. The first law banned dredging from a boat that is powered by anything other than sail, resulting in a fleet of specially designed sailboats called skipjacks being used to dredge oysters from the Bay. Once numbering perhaps in the thousands, the fleet of Chesapeake Bay skipjacks has been reduced to fewer than Tertiary thirteen today. Only a handful of watermen still sail these Consumers historic beauties of the Bay. While some watermen still wrestle with hand tongs, most have turned to power-driven patent Secondary Consumers tongs to save them the toil of the days past. During the 1880s, watermen caught nearly 20 million bushels of oysters per year. Since then, the oyster harvest has declined steadily. The Primary population of oysters in the Bay has been reduced by as Consumers much as 99 percent of its historic numbers. Phytoplankton REASONS FOR DECLINE OF THE BAY Overharvesting of oysters in the Chesapeake Bay has threatened Bacteria the oyster fishery with extinction. Both watermen and oyster Producers connoisseurs have demanded a solution to restore the Bay’s Decomposers & Detritus Feeders Chesapeake Bay Theme Day – Grades 3-4 6 oysters without putting a suspension on harvesting them. The preventing SAV from growing. After the algae dies, it sinks solution put forth by the Maryland Department of Natural to the bottom and is broken down by bacteria. This process Resources (DNR) was to regulate the industry. Methods of uses up much of the oxygen in the water, which threatens regulation include daily bushel limits, time limits, harvesting underwater life that needs oxygen. seasons, limited entries and periodic closures of harvesting sites. In addition, it is illegal to harvest oysters under 3 inches in Habitat loss has also caused major problems in the Chesapeake length, and any boat carrying a dredge can only use a motor Bay. Coastal development has increased steadily since 1970, on certain days of the week. and currently more than half the population of the United States lives in coastal counties. In the Chesapeake Bay watershed, The blue crab fishery is also suffering from overharvesting. population growth and development pressures have led to an To combat potential demise of the fishery, blue crab harvests increase in pollution and habitat fragmentation. are highly regulated based on size. Currently, hard shelled crabs must be 5 inches or larger to be harvested commercially. Please visit the State of Maryland’s Blue Crab Program website to learn about the Maryland DNR size regulations for blue WHAT YOU CAN DO FOR THE BAY crabs. dnr.state.md.us/fisheries/crab/crabindex.html Everyone can do something to protect the Chesapeake Bay. (Click on Regulations on the right hand side) For example, you can conserve water by turning faucets off when not in use and taking shorter showers instead of baths. Land-clearing for developmental or agricultural purposes has This will reduce the amount of water that has to be pumped led to increased sedimentation in the Bay. Sedimentation through sewage treatment plants or septic systems, which will refers to sand, clay, or silt that gets into the water column and conserve energy. You can also conserve energy by turning eventually settles on the bottom. Although sedimentation is a lights, radios and televisions off when not in use; running only normal process, increased sediment from dirt runoff can be full loads in the washing machine and dishwasher; and replacing harmful to the Bay’s aquatic life. It can clog oysters’ gills if ordinary light bulbs with energy-efficient bulbs. Conserving filtered in high quantities, suffocating them. It can also hinder energy will reduce the demand placed on fossil fuel plants, spat (young oysters) from successfully attaching to hard substrates. thereby reducing the pollution they produce. Of course, The presence of sediment in the water can block sunlight from “Reduce, Reuse, Recycle” is another important concept for Bay reaching the Bay’s underwater grasses, or SAV. Sedimentation conservation. In addition, it is important to reduce the amount in the water affects the turbidity of the Bay. Turbidity is a of fertilizer and pesticides we use in our gardens. In a practice measurement of the clarity of water. It is usually measured called bayscaping, you can incorporate native vegetation into with a Secchi (sek` key) disc, a circular plate that is divided lawns and schoolyards. Planting native trees and plants will into an “X” pattern of alternating black and white quarters reduce the need for fertilizer while providing habitat for na- and is tied to a rope. The Secchi disc is lowered into the water, tive animals and reducing the amount of runoff from lawns. usually from a boat or pier. When the “X” pattern of the Planting trees also prevents sedimentation. Tree roots keep disc is no longer visible, the depth is recorded using length soil in place so it does not run into the Bay. You can also limit increments along the rope. High Secchi depth values mean sedimentation by slowing down the flow of rainwater. This can that the water is clear. Low Secchi depth values indicate be done by installing a rain barrel to collect water as it flows high turbidity, usually due to a large amount of sediment off your roof from rain gutters. Simply picking up litter on and phytoplankton in the water. Turbidity can also increase the street will also help protect the Bay. Remember, the Bay’s due to pollution, dredging or during periods of elevated fresh- watershed extends over 64,000 square miles and covers six water input from rivers and streams. states plus Washington, DC, so make sure to ask everyone you know to do their part to help the Bay! Excess fertilizers wash off farm fields, golf courses and lawns into streams and rivers leading into the Chesapeake Bay. Once in the waterways, fertilizers designed to make crops healthy and lawns green promote the growth of harmful algae. As the algae grows, it blocks sunlight, thus Chesapeake Bay Theme Day – Grades 3-4 7 Glossary Bayscaping – a landscaping technique where native plants Food chain – a sequence that shows how each living thing and trees are planted to provide habitat for animals gets food and how energy is passed from organism to organism; organisms in a food chain can either be producers, consumers, Bivalve – a mollusk that has two shells; bivalves include or decomposers mussels, scallops, oysters and clams Habitat – the environment in which an organism or biologi- Blue crab – an edible crustacean with a flat abdomen and ten cal population lives or grows; there are four elements to a legs; bluish-green in color on top and white on the underside; habitat: food, water, shelter and space when a blue crab outgrows its exoskeleton, it molts Habitat fragmentation – the division of a large area into Brackish – a mixture of salt and fresh water smaller, isolated patches, separating the organisms that lived there; causes of habitat fragmentation include develop- Bushel – a basket that crabs, oysters, and other shellfish are ment, road building, logging and agriculture sold in; 1 bushel equals 32 dry quarts Harvest – collecting animals to sell for profit Consumer – an animal that eats producers or other consumers; this includes herbivores, carnivores, omnivores and scavengers High marsh – the portion of the marsh that is affected the least by the tides Crustacean – a mainly aquatic invertebrate that has jointed legs and must molt, or shed its exoskeleton, to grow; examples Low marsh – the portion of the marsh that is most often include crabs, lobsters and shrimp submerged during the tides; the plants in this area are most tolerant to the poorly oxygenated mud and daily submersion Decomposer – an organism that breaks down complex organic during high tides materials to get energy and nutrients needed for its own growth Marsh – a type of wetland that contains mostly tall grasses Dredge – a metal cage with small spikes on one side that is but few trees; serves as an important breeding ground for attached to a boat and dragged along the bottom of the Bay many animals to harvest oysters Maryland Department of Natural Resources (DNR) – a Ecosystem – a community of living organisms and their government agency that manages the health and recreational relationships with the non-living materials in a given area use of Maryland’s natural resources, including fresh and saltwater fish and shellfish Exoskeleton – the hard, shell-like covering of crustaceans (crabs, lobsters and shrimp); literally “outside skeleton;” must Mollusk – an invertebrate with a soft body covered by a thick be cracked open and discarded (molted) for animal to grow membrane; can have 0, 1, 2 or 8 shells; examples of shelled mollusks include clams, oysters, snails and scallops; octopuses Filter feed – a method of collecting food from the water; and squid are examples of mollusks without an external shell used by oysters, clams and other shellfish; involves drawing water in through an intake siphon, passing it over their gills, Molting – the process in which crustaceans grow larger; the and expelling the water through an exit siphon exoskeleton splits and the animal backs out of it to reveal a new, larger, soft exoskeleton which hardens after a few days Chesapeake Bay Theme Day – Grades 3-4 8