Black Sea Bass Encounter

Students collect, analyze, and discuss data on local fish population

This activity is an adaptation of “Shark Encounter” from the Lawrence Hall of Science: MARE 2002 curriculum. Adapted by: Kristin Hunter-Thomson

Download the pdf of this lesson

Topic:

Students simulate field research by working in small teams to collect, analyze, and discuss data on local populations of Black Sea Bass.

Audience:

Elementary, Middle, and High School

Length:

Two 40-minute class periods

NJ State Standards:

• 5.3.2.C.3 – Humans can change natural habitats in ways that can be helpful or harmful for the plants and animals that live there.

• 5.3.6.C.1 – Various human activities have changed the capacity of the environment to support some life forms.

• 5.3.8.E.1 – Individual organisms with certain traits are more likely than others to survive and have offspring in particular environments.

• 5.3.12.C.2 – Stability in an ecosystem can be disrupted by natural or human interactions.

Key Concept:

Fish population fluctuate over time and the actions of human can influence the fluctuations in positive and negative ways.

Introduction:

This activity is intended to help students understand how fisheries scientists collect and analyze data about the local fish populations. Through a simulate field seasons, students are exposed to what fish science in the field looks like. Also, students must analyze their data and compare it with the 40 years of actual Black Sea Bass data. The activity is meant to model the work of fisheries scientists and enable students to see natural fluctuations and the effects of humans on wild populations.

Background:

Black Sea Bass are important fish species in both commercial and recreational fisheries in New Jersey; they range from Maine to Florida. The Atlantic and Mid-Atlantic Fishery Management Councils manage the fisheries. The population decreased from the early 1970s to the late 1990s, but currently is recovering to higher levels. Black Sea Bass provide a good example of fluctuations in a fish population and successful fisheries management.

Overview:

Overall:

The three goals for the activity are:

• Estimate the current Black Sea Bass population in the Mid-Atlantic region.
• Determine what sorts of changes (if any) are occurring in the Black Sea Bass population over time.
• Decide what can be done to prevent damage to the Black Sea Bass population.

Session 1:

To prepare, create the Mid-Atlantic region on the floor of your classroom (Image of Mid-Atlantic region set-up with blue and green boundaries). There will be up to 100 quadrats laid out in the Mid-Atlantic region (black boxes in image). On the under side of the quadrats will be information about what happens in that space (see Resources below).

During the activity, students first are introduced to the activity goals and their challenge: given limited time and resources, how can they accurately estimate a Black Sea Bass population? Ask the students how a scientist migh accomplish these goals? After brainstorming ideas, students test their methods for data collection and afterwards classmates discuss why they place their confidence in one method over another.

Then present your students with a standardized method for sampling and estimating the population of an organism in the field. Students work in small research teams to randomly select study sites and conduct “fishing collection trips” to collect data. Once they have recorded their data they will work to analyze the raw data and convert it into a useable format. From the raw data students calculate the mean length of Black Sea Bass sampled, the sex ratio of the populations, estimates of the population density, and the percentage of males in different length bins within the population.

Session 2:

To prepare, make large replicas of the Black Sea Bass Data Over Time line graph (see Resources below). These data are of the total biomass (estimated size of the Black Sea Bass population in the ocean) and total landings (number of Black Sea Bass that were caught in the commercial and recreational fisheries) from 1968 to 2007 that are used in the Black Sea Bass Fishery Management Plan. If you had your students calculate the percentage of male Black Sea Bass in the population, also create a large replica of the Percent Male by Length graph (see Resources below).

Through the activity their goal is to determine an overall population estimate, account for any discrepancies, observe and compare their results with results from previous years, and determine if any meaningful recommendations can be generated for the future of the local Black Sea Bass population. During the activity, student teams share their data in a conference setting. After recording all of the class data, tell the students the actual size of the Black Sea Bass population and show them the graph with the Total Biomass of Black Sea Bass from 1968-2007. Using the data, ask the students to report on patterns over time in the Black Sea Bass population.

Then show the students the graph of Total Biomass and Total Landings of Black Sea Bass from 1968-2007. Again using the data, ask the students to report on patterns over time in the Black Sea Bass population. Engage the students in a discussion about comparing the total biomass and total landings over time. What does this mean?

Wrap-up:

1. Once the students have finished- distribute a sheet of paper and pen/pencil to each students. Have them do a “Quick Write” about: What are the short term, medium term, and long-term consequences to the total biomass of Black Sea Bass by increasing the amount of fishing pressure? What about decreasing the amount of fishing pressure? What arguments and evidence can you give to support your predictions?
2. Lead a whole group discussion and have students share their predictions with the class
3. Write the key concept (Fish populations fluctuate over time and the actions of humans can influence the fluctuations in positive and negative ways) on the board.
4. Ask the students if they have other observations or comments about the activity.
5. How do you think real marine organisms decide where and when they are going to migrate?

Materials:

For Session 1:

For the class:

• Poster of challenge goals
• Two 50-ft ropes to mark the boundaries of the Mid-Atlantic region
• 100 quadrats (1 ft x 1 ft)

For each student group:

• 1 bag of numbered pieces (poker chips, small tiles, pieces of paper, etc.)
• Calcualators
• 1 Clipboard
• 1 Data Sheet

For Session 2:

For the class:

• Graph of Black Sea Bass Data Over Time
• 1 sheet of large chart paper
• Colored Markers

For each student group:

• 1 sheet of 8.5″ x 11″ paper
• 1 pen/pencil
• 1 Clipboard

Safety Precautions:

Students must walk and interact with one another during the field season part of this activity.

Resources:

Data for the activity:

• Black Sea Bass Data Over Time (Graph and Data Table)
• Black Sea Bass Sex Ratio (Graph and Data Table)

Materials for the activity:

• Black Sea Bass Encounter Quadrats
• Black Sea Bass Student Data Sheet