Explanation for Benthos, Nekton, Plankton
Benthos:
Notes on Ocean Life Zones. What do benthos eat? Experiment-students will keep and feed live crabs different substances to see which stubstances crabs will grow the most from eating. (Lab)
 
Nekton:
Field trip to National Aquarium in Baltimore-students will classify 60 different nektonic organisms into phylums using key made in class.
 
Plankton:
Students will raise crabs and monitor the point at which crabs become nekton. (Lab)
 
 
 
Objectives
Benthos:
SWBAT...identify the different life zones of the ocean
-identify what benthos eat and why what they eats helps to identify them as benthos
 
Nekton:
SWBAT...-classify organsims in a more natural setting (aquarium)
 
Plankton:
SWBAT...identify the point at which crabs go from plankton to nekton, therefore identifying what differentiates plankton from nekton.
Materials
Benthos:
-larval crabs from research laboratory (~50 for each tank)
-different types of food (algae, brine shrimp, detritus blended into liquid, collected from local marine body of water)
-3 aquairums
-3% salinity sea water (you can buy sea salt at a pet store)
-salinity tester (found at pet store)
-pH test kit (pH should be between 5.0-6.5)
-3 thermometers
-3 protected filters (so larvae do not get sucked up into filter)
-3 heaters (temperture should be maintained at ~25C)
-3 sources of air and movement to water (water should be moving circularly in tank)
-3 heat lamps/timers
-compound microscopes for weekly observations
-eye droppers
-slides/coverslips
 
 
Nekton:
-student worksheets- see above
-field trip to aquarium (Admission is FREE to the National Aquarium in Baltimore for Maryland students)
 
Plankton:
-Student worksheets- see above
-use crabs and aquarium setups from Benthos Lab coincidingly
Procedure
Benthos:
-this lab can take anywhere between 3 to 6 months for observations so you may want to get this started at the beginning of your unit.
-present students with notes on the ocean life zones so they can relate the organsims they will be looking at from here on out with where they live in the ocean.
-set up aquariums and slowly acclimate crab larvae to tanks
-label each tanks as to what each set of larvae will be eating
-crabs should be feed 4x-5x a day (you could set up a feeding schedule for your students to come in and feed the crabs before or after class each day.  You may want to talk to your principle about how might be here at school on the weekend how could possibly take responsibility for feeding the crabs if you cannot make it in. I had a member of the custodial staff do it on Saturdays I came in one day to show him how, and a member of the church that meets in the gym on Sundays.)
-Salinity and pH should be taken on Mondays and Fridays.
-The heat lamps should be on timers and set to be on for about 16 hours a day.  It is best to have them come on during the night when the sun is not out and the lights in the room are off to help maintain temperature.
-explain lab objectives and procedures to students
-have students come up with a hypothesis (use if, then format)
-show students how to properly care for the larvae
-at a set time (2x a week) of the week students should be given class time to record data on the larvae.  Students should be measuring the width of the larvae, taking 3 samples of larvae for each aquarium to get a good range of larvae into measure.  Students should be recording the number of larvae in each sample and totaling the numbers for each day of sampling for each aquarium.  Students should also be estimating a percentage of the tank that food still occupies in the tank on the day of sampling.  For example, if there is no food left in the tank then students should record 0%.
-Students should come up with a relationship to the type of food, the number of mortalities, and the rate of growth of the larvae.
-Students will graph all 3 aspects above and answer conclusion questions. They will also be drawing and identifying each larval stage.
-If possible allow students to take photographs of the larvae at each stage.  This is possible if your school has an attachment for the microscope to use a digital camera or a microscope that can take pictures/video.
-Discuss with students results of lab on a periodic basis. 
-Explain to students the threats, trials, and survival rate that larvae in the environment have.  You may also want to discuss the need for larval transportation before they become nekton.
 
 
Nekton:
-set up aquarium field trip
-before you take students on the field trip to the aquarium, have students prepare the same Semantic Feature Analytic Grid with the same questions they came up with in class.  Instead of classifying pictures they will be classifying 60 live organisms.
-as students go through the aquarium they should record the names of 60 organisms and then use their questions to categorize them into the correct phylum.
-collect and check for accuracy
 
 
Plankton:
-While students are going through benthos lab, they should also be making observations as to at what point the crabs stop being plankton.  When the larvae can swim independently on their own, (usually at the end of the megalops stage) they have become nekton.
-Students should be making these observations when they sample for the Benthos lab.
 
References
(You can set up your field trip to the National Aquarium in Baltimore here)
 
State Standards
1.1.2- The student will modify or affirm scientific ideas according to accumulated evidence.
1.2.1- The student will identify meaningful, answerable scientific questions.
1.2.3- The student will formulate a working hypothesis.
1.2.4- The student will test a working hypothesis.(NTB)
1.2.6- The student will identify appropriate methods for conducting an investigation (independent and dependent variables, proper controls, repeat trials, appropriate sample size, etc.).
1.2.7- The student will use relationships discovered in the lab to explain phenomena observed outside the laboratory.
1.3.1- The student will develop and demonstrate skills in using lab and field equipment to perform investigative techniques.(NTB)
1.3.2- The student will recognize safe laboratory procedures.
1.3.3- The student will demonstrate safe handling of the chemicals and materials of science.(NTB)
1.3.4- The student will learn the use of new instruments and equipment by following instructions in a manual or from oral direction.(NTB)
1.4.1- The student will organize data appropriately using techniques such as tables, graphs, and webs (for graphs: axes labeled with appropriate quantities, appropriate units on axes, axes labeled with appropriate intervals, independent and dependent variables on correct axes, appropriate title).
1.4.2- The student will analyze data to make predictions, decisions, or draw conclusions.
1.4.3- The student will use experimental data from various investigators to validate results.
1.4.5- The student will check graphs to determine that they do not misrepresent results.
1.4.6- The student will describe trends revealed by data.
1.4.7- The student will determine the sources of error that limit the accuracy or precision of experimental results.
1.4.9- The student will use analyzed data to confirm, modify, or reject an hypothesis.
1.5.1- The student will demonstrate the ability to summarize data (measurements/observations).
1.5.2- The student will explain scientific concepts and processes through drawing, writing, and/or oral communication.
1.5.4- The student will use tables, graphs, and displays to support arguments and claims in both written and oral communication.
1.5.5- The student will create and/or interpret graphics. (scale drawings, photographs, digital images, field of view, etc.)
1.5.7- The student will use, explain, and/or construct various classification systems.
1.5.8- The student will describe similarities and differences when explaining concepts and/or principles.
1.5.9- The student will communicate conclusions derived through a synthesis of ideas.
6.2.3- The student will conclude that populations grow or decline due to a variety of factors. At least Linear/exponential growth Carrying capacity/limiting factors Species specific reproductive factors (such as birth rate, fertility rate) Factors unique to the human population (medical, agricultural, cultural) Immigration/emigration Introduced species
Lesson Resources