Georgian Court University
Food Webs in the Barnegat Bay
Time Frame: One to Two 45 Minute Periods
Students will review their prior knowledge of food webs and chains and the associated terminology when discussing the various organisms present in the Barnegat Bay. They will create a graphic organizer for reference and reinforcement of the different types of consumers. Students will also gain appreciation for the unique environment present in an estuary and will evaluate the effects a change in freshwater supply can have on the salinity and thus the animals in the area. Finally students will collaborate in a group and create their own food web involving the organisms from the bay in order to explain to the class and to post in the hall or classroom to remind them or to show others what they have learned.
Image source: http://www.somethingfishy.ie/teacherslessons/lesson7/EstuaryFoodWebB.gif
NJ Core Content Standards
STANDARD 5.1 (Scientific Processes) All students will develop problem-solving, decision-making and inquiry skills, reflected by formulating usable questions and hypotheses, planning experiments, conducting systematic observations, interpreting and analyzing data, drawing conclusions, and communicating results.
A. Habits of Mind
· Evaluate the strengths and weaknesses of data, claims, and arguments.
· Communicate experimental findings to others.
· Recognize that curiosity, skepticism, open-mindedness, and honesty are attributes of scientists.
B. Inquiry and Problem Solving
· Identify questions and make predictions that can be addressed by conducting investigations.
· Collect, organize, and interpret the data that result from experiments.
STANDARD 5.8 (Earth Science) All students will gain an understanding of the structure, dynamics, and geophysical systems of the earth
B. Atmosphere and Weather
· Describe and illustrate the water cycle.
D. How We Study the Earth
1. Utilize various tools such as map projections and topographical maps to interpret features of Earth's surface.
STANDARD 6.6 (Geography) All students will apply knowledge of spatial relationships and other geographic skills to understand human behavior in relation to the physical and cultural environment.
A. The World in Spatial Terms
· Translate maps into appropriate spatial graphics to display geographical information.
· Use geographic tools and technologies to pose and answer questions about spatial distributions and patterns on Earth.
B. Places and Regions
· Explain how regional systems are interconnected (e.g., watersheds, trade, transportation systems
Spatial, Kinesthetic, Linguistic, Interpersonal, Intrapersonal, Logical, Naturalistic
o Be able to describe the main components of the Barnegat Bay food web
o Demonstrate their understanding of the material presented by the teacher by filling out a graphic organizer about food webs.
o Analyze the various components of a food web and how they interact.
o Assign different organisms in the Barnegat Bay food web to an appropriate level on the food web (producer, consumer, herbivore, carnivore etc.).
o Construct a food web involving animals from the Barnegat Bay with a group.
o Describe how organisms within a food wed are all interconnected and thus can be affected by changes in their environment, such as decreased freshwater inputs to the Bay.
Teacher will ask students what types of animals they notice in their area in nature.
Teacher can start off a conversation with deer, heron, crabs, etc.
After students share their ideas of animals they have seen in the wild, teacher will establish that a majority of the animals mentioned including over thousands of other organisms depend on the Barnegat Bay estuary.
1) As the students understand the importance of an estuary and the animals that are dependent on it, students will review their prior knowledge on food chains and food webs.
2) Students will be prompted to recall the different types of consumers in a food chain. Teacher can initiate the terminology (consumer) or the definition (an organism that only eats meat) in order for the students to become involved to answer as they recall information.
3) If needed for reference for those less familiar with food webs, students will receive a graphic organizer (supplied) to fill out as they view a PowerPoint presentation.
4) Students will be presented with PowerPoint slides provided about the different terms and pictures about the different types of consumers that are specifically found in the Barnegat Bay.
5) Before, during and after presentation, teacher should emphasize the importance of the sea grasses of the Barnegat Bay, focusing on the eel grass and widgeon grass. These are a large component to the bottom of the food chain in the Barnegat Bay in which many animals depend on for food, shelter, mating, development, filtration, and photosynthesis for oxygen and energy.
Teacher can ask students if they can recall finding black “seaweed” on the shore of the bay, this is usually dead eel grass that has been washed up.
6) After students have become well-acquainted with the food web in the Barnegat Bay, students will each be given a different animals found in the Barnegat Bay with information of what that animals eats.
7) Students will use their prior knowledge and teamwork (and graphic organizers if applicable) to decide which type of consumer they each have. It is important for students to understand that many of the animals can be considered more than one type of consumer depending on what it is eating in the food web.
For example: A student that has the terrapin turtle which eats clams, worms, snails, crabs, and vegetation can find and talk to students that have any of these organisms. Depending on the organisms the student investigates, such as the clams (filter feeders) or snails (herbivores) which are primary consumers make the turtle a secondary consumer. The turtle can also resolve that since he eats vegetation the turtle can also be a primary consumer, but because the turtle is an omnivore, the student should investigate in another organism other than plants. The student can also investigate crabs which eat multiple primary consumers (snails, worms, fish, clams, oysters) making the crab a secondary consumer (or decomposer since it also eats detritus) which in turn makes the turtle a tertiary consumer.
It is important for students to not only focus on what type of consumer their animal is, but also appreciate the various types of organisms they can eat as they go higher in the food chain, but without the organisms in the lower sections, there would not be secondary and tertiary consumers.
An additional challenge to the above activity:
8) Students can then collaborate in groups or as a whole (if it does not become too overwhelming) and use a poster board, classroom bulletin board, or chalkboard with magnets to create a food chain, or web (depending on how ambitious you and your students are feeling). Preferably they should be created in an area that can be shown for the entire class, for the rest of the curriculum, or longer. This can even be done on a sheet of paper and photocopied for each student to keep in their science notebook.
9) Once the teacher has assisted in the creation, and checked it over the students can also create the arrows in which complete the food web or chain.
10) Teacher will then emphasize what was taught in the previous estuary lesson about the unique salinity of the Barnegat Bay and how important it is for the survival of the grass beds.
11) Teacher will then point out the plants at the bottom of each food chain, to show the support it offers to the rest of the community of organisms.
12) Using the PowerPoint image or creating a poster board of your own, present students with the components of a food chain and show them the occurrence of too much salt coming into the Barnegat Bay, which would kill the sea grasses (pull sea grasses off of poster board or click for removal on PowerPoint).
13) Students will be prompted to think about how this would affect the rest of the environment and food chain. (Teacher can ask: What would happen without the sea grasses? What organisms depend on them? What do you think happens to these organisms?)
14) Once the realization that various primary consumers, including those who just live in the sea grasses for protection, would not survive because of the loss of food or protection, students may be chosen to remove the organisms off the poster board or name the organisms that would be removed from the PowerPoint food web to ensure there is an understanding of the food web concept.
15) These steps would continue for secondary and tertiary consumers, until most of the food web is empty.
16) In addition, the teacher should explain to the students that increased salinity levels in the Barnegat Bay will introduce other unwanted organisms into the area, such as sea stars that eliminate the clams such as those planted through the “Reclamming the Bay” program, or the increased population of stinging jellyfish during the summer.
Note to teacher
· Some students may realize that many of the organisms depend on multiple types of organisms and may still survive if only some of their prey has been removed. If this occurs, these organisms can remain on the web, until all of their food has been removed, which will probably happen.
· Increased salinity, such as an organism’s intolerance of the changing water, even before their food has been eliminated. This forces the sensitive organisms to leave the bay area or die.
· Countless organisms that live in the ocean enter the Barnegat Bay and lay their eggs in the sea grass beds for protection as they develop and feed on the grass until they get larger and return to the ocean. Without the sea grass beds alone these ocean dwellers would have problems producing new offspring.
Teacher should finish the lesson by challenging the students to recall the connection between the lessons from the water cycle to this day’s lesson. Teacher can prompt students to connect the information by giving key terms, such as: ground water, aquifer, watershed, brackish water, estuary, wild animals of the Barnegat Bay.
**The key is for students to understand that wasting the fresh water collected from the groundwater and aquifer system removes the fresh water that would enter the Barnegat Bay. This reduces the fresh water entering the bay, increases the salinity, removes a large amount of the brackish water, the unique component of the estuary, and cannot support the organisms that depend on the specific environment.
To assess this, depending on time students can either:
Have a classroom discussion about the new organisms they learned about, such as the food some of the organisms ate, the types of feeding habits other has, their favorite organism, least favorite.
Write on an exit slip, one thing they learned today about the Barnegat Bay animals and the food chain/web.
If live animals are available have students work with the flash cards where possible (we don't have flashcards for everything you'll catch and some of the flashcards are for species that won't be caught with a seine net), to learn more about them. Working with guides like Peterson's "Field Guide to the Atlantic Seashore" (usually available in your local public library if not in your school's library) is also helpful here.
Students can be given a new animal involved in food webs and a producer would be chosen to hold a ball of yarn. The students would ask who ate ‘their organism’ and would then pass the ball of string to them, to demonstrate the energy being passed. The next student would ask who ‘ate them’ to pass the yarn again. Once the ball had reached a tertiary consumer that was eaten by any other organism, the yarn would go to another student who was producer and the game would start again. This would continue (3 - 4 times) for all students to hold the yarn. Once this happens, the teacher can pretend to be a sea star and eliminate the clams, or remove a plant because of the high levels of salinity (all caused by wasting water). Once the plants were eliminated the organisms holding the yarn connected to that producer would also drop their yarn. This would continue, and again would restart once the chain effect had finished and more students were left.
**Note to teacher: In this situation, all students will not become eliminated if an unexpected web is formed. The focus should be on the negative effects wasting water would have the Barnegat Bay in general, and even one or two organisms disappearing can be devastating to our area.
Habitats of the Barnegat Bay. http://library.fws.gov/pubs5/web_link/text/bbc_form.htm
Estuarine Food Web: http://www.teara.govt.nz/en/estuaries/2/2
Estuaries.gov Estuary Page: http://www.estuaries.gov/
Another nice set of lesson plans on Estuarine Food Chains and Food Webs: http://www.padillabay.gov/lessons/lesson-FoodWeb.html
Encarta Estuary Page: http://encarta.msn.com/encyclopedia_761570978/estuary.html
Introduction to Estuarine Food Webs: http://coastgis.marsci.uga.edu/summit/k12foodweb.htm
Estuarine Food Chains and Food Webs: http://www.oregon.gov/DSL/SSNERR/docs/EFS/EFS29estchain.pdf
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© 2009. Amanda Traina (Author), Louise Wootton (Editor)