Engaging Students by Monitoring Sand Crabs Through LiMPETS
Posted: Tuesday, May 5th, 2015
by Jeff Kepper
Engaging Students by Monitoring Sand Crabs through LiMPETS
Many visitors to California’s beaches have witnessed young children digging in the sand for an elusive creature, the sand crab or Emerita analoga. The sand crab is a crustacean related to crabs, shrimp and lobster that inhabits the area of the beach where waves break on the beach (Bryant, 2006). Sand crabs can be found surfing waves from Alaska to Chile (Jaramillo, Dugan, & Contreras, 2000). Emerita analoga is the ideal species to engage students through scientific research because of its presence on most beaches.
Field research offers opportunity for students to learn about science in a setting that is very different than the classroom (Hudak, 2003). It places student in “real” world setting that allows them to develop skill that are difficult to teach in the classroom (Lei, 2010; Switzer,1995). Participating in field research is a great way to increase learning, foster strong connections between participants, and engage students (Lei, 2010). With a minimal amount of equipment and training, young scientists can be introduced to field research, implement monitoring protocols, and participate in relevant scientific research on coastal ecosystems.
Long-Term Monitoring Program and Experiential Training for Students (LiMPETS)
LiMPETS was established in 2002 to introduce students to hands-on monitoring and scientific research. This program was designed to have students monitor coastal ecosystems of California Marine Sanctuaries. Monitoring programs are needed to establish baselines for abundance and distribution of organisms. It is difficult to determine if biodiversity is affected by natural or anthropocentric causes without sustained long-term monitoring (Addessi, 1994). By surveying smaller areas through transects, researchers can extrapolate their findings to the larger system (Holt et al., 2013). These baselines allow researchers to compare populations and make hypotheses about factors that might be affecting sand crab survival (LiMPETS, 2013). The aim of LiMPETS is to increase awareness and stewardship of sensitive coastal ecosystems. There are two LiMPETS monitoring programs: the rocky intertidal monitoring and the sandy beach monitoring. The sandy beach program focuses on Emerita analoga.
Monitoring Sand Crabs at Mission Beach in 2014
Classes from Helix Charter High School in La Mesa monitored sand crabs on two dates in the spring and fall of 2014 at South Mission Beach in San Diego, California. This was the first time that LiMPETS protocols were used to monitor this location. This beach was chosen based on the presence of sand crabs, safety (mild surf), and proximity to school. At the monitoring location students sample for sand crabs along a 10-meter transect that runs perpendicular to shoreline and into the surf. At each meter interval along the transect a core sample of sand is taken and sieved for sand crabs. Captured sand crabs are measured and their gender is determined. On two monitoring dates in 2014 the students captured 54 sand crabs in 100 cores (see Figure 1). Many of the captured sand crabs were smaller than 10 millimeters. The students expected to capture a greater number of larger sand crabs (over 10 millimeters). This was probably due to the number and size of sand crabs they practiced with in the classroom (see attached lesson). Even though their expectations were not met, most students thought that the experience of collecting data in the field was a worthwhile experience.
Students were asked after their field experience about monitoring sand crabs, and whether they would recommend the sand crab monitoring program to other students. The value of participating in LiMPETS programs can be seen from the following student comments:
“Besides the learning, it’s a great way to introduce science in a fun and entertaining way. It involves a lot of teamwork and patience. It also engages the students in science.”
“We were able to gather immediate information instead of waiting a couple of hours in the classrooms to get data. The field was more hands-on and interesting, but it was harder to get data at the beach. It is more difficult because the beach is always changing.”
“It was amazing! I thought that we were going to do a lot of hard work but it actually was so much fun it didn’t feel like work. It was more involved and detailed than I thought it was going to be.”
The experience in the field for students is very different than in the classroom. They really enjoy participating in science in a field setting. Several students that completed the monitoring last spring have asked to participate again this year on a Saturday. LiMPETS programs are a great way to get students engaged and excited about science.
Linked below is a lesson to prepare your students for LiMPETS sand crab monitoring. The lesson could be used with many different organisms. I have used bees, pill bugs, and hermit crabs for similar lessons. To learn more about LiMPETS and how to be trained for LiMPETS monitoring, visit the following website: www.limpets.org
Monitoring Sand Crabs: An Inquiry Lesson for Secondary Students
The initial lessons for monitoring sand crabs provide the students with the information required to complete the monitoring protocols. The first anatomy lesson is designed to capture the students interest and help them generate questions that could be answered with further investigation. The activity is called, “I Notice, I Wonder”. In this activity, pairs of students are given a live sand crab to observe and record their observations. Making sound observations is an essential practice of science (Oguz-Unver & Yurumezoglu, 2009).
Monitoring sand crabs requires young scientists to acquire the proper techniques of data collection. In this activity students will learn important anatomical features of sand crabs. They will also be trained on measuring carapace length and identifying gender of sand crabs.
Next Generation Science Standards for LiMPETS monitoring
HS-LS2 Ecosystems: Interactions, Energy, and Dynamics
HS-LS2-1. Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
HS-LS2-2. Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.
HS-LS2-7. Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
HS-LS4-4 Biological Evolution: Unity and Diversity
HS-LS4-5. Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.
- Sand crabs (Instructor will need California Fish license or Collecting Permit to collect)
- Magnifying glass or dissecting scope
- Calipers (Individual calipers can be purchased at Harbor Freight Tools for $2.99 plus tax)
- Sand crab practice cards (Available on LiMPETS website)
Students work in small groups with one live sand crab. Each student writes down observations about their sand crab (number of appendages, color, number of antennae, segments of body, how it moves, how it swims, etc.). The groups are then given a dissecting scope or hand lens and come up with additional observations. Once their initial observations are complete, the students draw their sand crab (see Figure 2). The student’s observations are shared with the class. Examples of the “I Notice” observations from the students included the following: size, movement or lack of movement, color, number of appendages, and method of movement.
After sharing their “I Notice” observations, students generate a minimum of three questions in the “I Wonder” portion of the activity. Questions are written on the far side of the paper opposite their observations. The questions facilitate the discussion on sand crab background. After the question and answer portion of the activity, each student labels anatomical features of sand crabs on their drawing (see Figure 3). The “I Notice, I Wonder” activity engages the students. They are free to use their curiosity and explore to make observations and generate questions. Their questions drive the discussion portion of the lesson. Students are asked to determine which “I Wonder” questions they could investigate scientifically. This lesson transitions into determining the sex and measuring the carapace or outer shell length of sand crabs.
Gender Identification and Measuring Exercise
One emphasis of the LiMPETS monitoring program is the proper collection of data. As students make observations in the “I Notice, I Wonder” lesson, they are introduced to the crab’s anatomical structure. This knowledge will be necessary for them to complete the monitoring process. Students have to learn how to correctly measure carapace length and determine the sex by locating the presence or absence of pleopods on sand crabs. Sand crab females have three pairs of pleopods to manage the eggs. Males do not possess pleopods. To practice determining sex and measuring carapace length, LiMPETS provides sand crab playing cards (see Figure 4). These cards allow students to practice measuring the standard lengths used in the monitoring protocols on one side of the card and sex determination on the other. Calipers are used to measure the standard length (which is the length of the carapace). By lifting the telson and locating the pleopods, sex can be determined (see Figure 3). Students work in groups, first identifying sex and measuring eight sand crabs on the practice cards, then repeating the process with five live sand crabs. All of their data are recorded in their practice data table (see Figure 5). By reviewing the student’s measurements, the instructor can determine which groups need additional practice. After this lesson, the students would learn the protocols for monitoring in the field.
Addessi, L. (1994). Human disturbance and long-term changes on a rocky intertidal Community. Ecological Applications, 4 (4), 786-797.
Bryant, P. J. (2006). Pacific sand crab (mole crab), Emerita analoga. Natural History of Orange County, California, University of California, Irvine. Retrieved from
Holt, B. G., Rioja-Nieto, R., Aaron MacNeil, M., Lupton, J., Rahbek, C., & Peres-Neto, P. (2013). Comparing diversity data collected using a protocol designed for volunteers with results from a professional alternative. Methods in Ecology & Evolution, 4(4), 383-392.
Hudak, P. (2003). Campus field exercises for introductory geoscience courses. Journal of Geography, 102, 220-225.
Jaramillo, E., Dugan, J.E., Contreras, H. (2000). Abundance, tidal movement, population structure and burrowing rate of Emerita analoga (Anomura, Hippidae) at a dissipative and a reflective sandy beach in south central Chile. Marine Ecology, 21(2), 113–127.
Lei, S.A. (2010). Assessment practices of advanced field ecology courses. Education, 130(3), 404-415.
LiMPETS (2013) Long-term monitoring program and experiential training for students. Retrieved from www.limpets.org
Oguz-Unver, A., & Yurumezoglu, K. (2009). A teaching strategy for developing the power of observation in science education. Online Submission.
Switzer, P.V. (1995). Campus field trips: An effective supplement to classroom instruction. Journal of College Science Teaching, 24, 140-143.
Jeff Kepper is a teacher at Helix Charter High School in La Mesa, CA and is a member of CSTA
Posted: Tuesday, March 14th, 2017
The pre-publication version of the new California Science Curriculum Framework is now available for download. This publication incorporates all the edits that were approved by the State Board of Education in November 2016 and was many months in the making. Our sincere thanks to the dozens of CSTA members were involved in its development. Our appreciation is also extended to the California Department of Education, the State Board of Education, the Instructional Quality Commission, and the Science Curriculum Framework and Evaluation Criteria Committee and their staff for their hard work and dedication to produce this document and for their commitment to the public input process. To the many writers and contributors to the Framework CSTA thanks you for your many hours of work to produce a world-class document.
For tips on how to approach this document see our article from December 2016: California Has Adopted a New Science Curriculum Framework – Now What …? If you would like to learn more about the Framework, consider participating in one of the Framework Launch events (a.k.a. Rollout #4) scheduled throughout 2017.
The final publication version (formatted for printing) will be available in July 2017. This document will not be available in printed format, only electronically.
Posted: Monday, March 13th, 2017
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by Marian Murphy-Shaw
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Posted: Monday, March 13th, 2017
by Joseph Calmer
Probably like you, NGSS has been at the forefront of many department meetings, lunch conversations, and solitary lesson planning sessions. Despite reading the original NRC Framework, the Ca Draft Frameworks, and many CSTA writings, I am still left with the question: “what does it actually mean for my classroom?”
I had an eye-opening experience that helped me with that question. It came out of a conversation that I had with a student teacher. It turns out that I’ve found the secret to learning how to teach with NGSS: I need to engage in dialogue about teaching with novice teachers. I’ve had the pleasure of teaching science in some capacity for 12 years. During that time pedagogy and student learning become sort of a “hidden curriculum.” It is difficult to plan a lesson for the hidden curriculum; the best way is to just have two or more professionals talk and see what emerges. I was surprised it took me so long to realize this epiphany. Learn More…