Biology & Life Sciences Chapter 15 What Other Factors You Need Consider When

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Lab 15

Fishing Down the Food Chain

Description of the Lab

Students will use real fisheries data sets to look at the change in US commercial

fisher catches over time. Changes in Atlantic Cod, Alaskan Pollock and Oregon

commercial landings will be investigated. Students will be asked to use the NOAA

Outline of Investigation

Exercise 1 – Analysis of Commercial Fish Catches Over Time

Materials needed:

• Data for analysis of Commercial Landings US Fisheries,

Note: Data provided are summaries chosen to allow multiple aspects of this topic to be

investigated in a short period of time. Some resolution is lost as a result. More complete

data sets are available at www.st.nmfs.noaa.gov.

Exercise 2 – Sustainable Choices

Materials needed:

• Access to some of the following seafood vendors:

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Note: If access to seafood vendors is an issue, there are chains that sell groceries online.

If your area supports a large Asian grocery store, you might encourage students to visit.

The variety of species sold may be larger than at standard chains and there are often tanks

with live organisms.

Answers to Questions for Lab 15

Exercise 1 – Analysis of Commercial Fish Catches Over Time

1. Commercial landings US Fisheries 1950-2010.

a) What is the trend over time?

b) When did landings peak in the United States?

According to the data table provided 199.5

c) How does this compare to the world commercial marine catch shown in Figure

15-1 (note the units for the World data are millions of metric tons compared to

metric tons for the US data)?

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Commercial Landings Atlantic Cod 1950-2010

a) What is the trend over time?

b) When did the Atlantic Cod landings peak in the United States?

c) How do the peaks compare between the overall US fisheries data and the

Atlantic Cod?

d) If they are different, why do think this is the case?

Answers will vary: Other species were being targeted, overall fishing

effort increased in other stocks etc.

Commercial Landings Alaskan Pollock

a) What is the trend over time?

b) When did the Alaskan Pollock landings peak in the United States?

According to data in table provided 2005.

c) How do the peaks compare between the Atlantic Cod and the Alaskan Pollock?

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d) What are some possible reasons for the lack of data for 1950, 1955, and 1960?

These data are for US fisheries landings only, there was not a domestic

Commercial Landings for Oregon 1950

a) How many landing categories (i.e., species) are listen in 1950?

b) How many invertebrate species are listed in 1950?

Commercial Landings for Oregon 2010

a) How many landing categories (i.e., species) are listed in 2010?

b) Would changes in fishing pressure be the only reason the number of categories

would increase? What other factors do you need to consider when interpreting

these data?

Answers will vary, but species data is something recorded under a broad

c) How many invertebrate species are listed in 2010?

Approximately 17 (answers will vary depending on how students count the

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d) Do you see evidence of new fisheries developing?

e) Do you see evidence of organisms in lower trophic levels being targeted?

Exercise 2- Sustainable Choices

a) How many different types of seafood were sold?

b) What were the countries of origin?

Answers will vary, students will also find that this is sometimes difficult to

c) Was it possible to assess whether or not the item was a sustainable choice or

not? (Describe what criteria you used to assess ‘sustainability’.)

d) Was it possible to purchase seafood from the port that is nearest to your

location? i.e., can you buy local?

e) Were there differences between the different kinds of stores? (Use the group

data to answer this question.)

Answers will vary. Students may be surprised find that Wal-Mart set a goal

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Answers to Questions for Lab 15

1. You are having a casual conversation about overfishing and mention that if trends

continue the way they are now we might all end up eating jellyfish. Obviously, you

are using this to make a point. Assuming the other people you are conversing with

are not well acquainted with the history of fisheries conservation, write a brief

description of what the point was you were trying to make using the topic of “Fishing

Down the Food Chain” as the focus in your explanation.

Answers will vary: Overharvesting valued marine species at higher trophic levels

2. Research five types of technology developed in the past 125 years that have enabled

us to get to the point of fishing the oceans out of most of its commercially valuable

species at such a rate that we have to resort to fishing at lower trophic levels in order

to still harvest protein from the sea. Discuss how each type of technology contributed

to the over-harvesting problem.

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3. Contrast the differences between the species approach and ecosystem approach to

wildlife management. Provide specific examples of each and discuss the pros and

cons of the two types of management approaches.

The species approach to wildlife management focuses on the preservation of one