Fish is an important food worldwide, providing billions of people with essential protein and nutrients. Yet, overfishing has caused global declines in fish stocks and threatens the health and livelihood of people across the world. In the first part of this unit, high school students will gain an understanding of overfishing and what can be done to counter it through the lens of a target species, the California white Seabass. In the next lesson, students will learn that scientists can study the fossil remains of fish in order to study long term changes in fish populations. In the third lesson, students will learn why and how fisheries scientists dissect fish by examining the external and internal structures of a fish head and remove the fish’s otoliths, or “ear bones”. In the final lesson, students will design their own goldfish experiment to test which environmental variables influence goldfish growth.

  • Fish Biology – ecology, habitat, physiology, anatomy, life cycle, growth patterns.
  • Human Impacts / Climate Change / Overfishing.
  • Fossils / Marine Sediments / Studying the past to better understand the present.
  • Experimental Design / Analyzing and Interpreting Data.
  • Students will learn why fish stock enhancement is through raising White Seabass in the classroom.
  • Students will understand how fisheries scientists study historic fish populations.
  • Students will identify and describe the appearance and function of external and internal structures of fish anatomy.
  • Students will dissect the otolith, or “ear bone” from the salmon head.
  • Students will know the function/role of the otolith for the fish and what a fisheries scientists can learn from studying them.
  • Students will design their own experiment to test which environmental variables influence goldfish growth.
  • Students will analyze experimental results.
  • All fisheries are well studied and managed.
  • Fossils are all very old.
  • Climate change and natural climate variability are different.
  • Only tree have growth rings.
  • The impact of human activity on animal growth is too small to measure.
  • Only food and temperature controls fish growth.
  • Human actions in the context of “global change” always negatively influences animals.
  • Through a research project and presentation focusing the California White Seabass, students will gain an understanding of overfishing and the process of making sustainable fisheries management decisions. Students will also learn some solutions to overfishing, namely hatcheries and stock enhancement programs. They may also join Hubbs-Seaworld Research Institute’s Seabass in the Classroom Program*, where they will be part the overfishing solution by raising juvenile White Seabass in the classroom and releasing them into the wild. (*There are significant costs to the program, which may be prohibitive).
  • Students will learn how and why scientists study historic fish populations. The lab consists of 5 different stations, which simulate steps a scientist takes to remove and identify fossil remains from marine sediments. Students will learn that sediment cores record environmental changes and biological remains.
  • In fish, otoliths, or ”ear bones”, help with balance, orientation, and hearing. For scientists, otoliths can reveal information about the age, size, and growth of a fish. Students will learn hands on why and how fisheries scientists dissect fish by examining the external and internal structures of a fish head and remove the fish’s otoliths. The students will measure the lengths of their otoliths and use that data to reconstruct an estimated body length size of their salmon. They will then compare the fish size structure data between the two types of salmon that were dissected (farmed Atlantic salmon and wild caught Chinook salmon).
  • The growth of an organism is influenced by a variety of biotic and abiotic environmental variables. Through direct and indirect alteration of these environmental variables, human actions are perturbing the natural growth patterns of many organisms worldwide. Through an analysis of the otolith growth rings, students will begin to learn how natural climate variability and human actions can influence growth fish. Students will then design and test their own hypotheses about fish growth by altering the environmental variables of a goldfish tank and observing the impact these alterations have on goldfish growth.
  • This unit was designed for a 9th grade marine biology class in San Diego, CA. Each day is meant for a 90-minute period. The lesson could easily be adapted for 10-12 grades as well as shorter class periods. The lessons can also easily be switched in order or used as stand-alone lessons, rather than as a complete unit.
  • Each lesson involves student assessment through in-class activities and discussions. Lab write-ups, work sheets, and poster presentations are used as formal assessment tools in this unit.
  • Each PowerPoint is annotated with teacher instructions and notes. Several lessons come with additional background information for teachers. Student labs and worksheets also have a teacher version with detailed instructions on materials and methods. One of the challenges for this unit is getting some of the materials and takes coordination the teacher’s part (e.g., White Seabass collaboration with HUBBS, Fish heads, Sediment material, fish tanks for goldfish experiments).
  • For the final project of the unit, students will complete a follow-up activity that combines everything they’ve learned about in the unit. Students will analyze and present the results from either the goldfish growth experiments or the data collected from raising the White Seabass.
  • HS-LS2-1: Quantitative analysis of ecosystem function/carrying capacity.
  • HS-LS2-2: Quantitative analysis of biodiversity and populations.
  • HS-LS2-3: Aerobic and anaerobic processes.
  • HS-LS4-2: Using evidence to explain influences on organisms.
  • HS-LS4-3: Statistical analysis of distribution of traits.
  • HS-LS4-5: Environmental influences on organisms.
  • HS-LS4-6: Design solutions for human impacts on biodiversity.

Measuring White Seabass Juvenile

Alaskan Salmon Head

Fish Head Dissection
Lesson Specifics
  • Grade Level: 9th grade marine biology class
  • Time Frame: 90-minute period per lesson

R/V Roger Revelle

Scripps Pier
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