Earth 540: Essentials of Oceanography for Educators
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Lesson 9

The Secret Lives of Fishes and the Great Meal Deal

About Lesson 9

Contact the instructor if you have difficulty viewing this image
Source: http://www.aquamaps.org

Map showing native range for Gadus Morhua (Altantic Cod). Distribution: Northwest to Northeast Atlantic: Cape Hatteras to Ungava Bay along the North American coast; east and west coast of Greenland; around Iceland; coasts of Europe from the Bay of Biscay to the Barents Sea, including the region around Bear Island.

In this lesson, we will review life in the ocean and focus in particular on aquaculture and the problems of overfishing.

By the end of this lesson you should be able to describe the main elements of the food chain in the ocean, including the importance of photosynthesis and phytoplankton. You should also be able to summarize current practices and trends in aquaculture and the main threats to natural marine fisheries.

 

What will we learn in Lesson 9?

By the end of Lesson 9, you should be able to:

  • Describe the food chain in the ocean
  • Explain why photosynthesis is important to life in the ocean
  • Explain the importance of nutrients in the ocean
  • Explain the energy cycle of the ocean, with specific reference to nutient cycling
  • Describe the spatial distribution of life in the ocean and give reasons why fish biomass is concentrated where it is
  • Describe aquaculture including where it is practiced, recent trends in farmed fish, and salient pros and cons of aquaculture
  • Describe the state of ocean fisheries and summarize the main threats to fish populations in the ocean
  • Explain what is being done to save marine fisheries and the nature of the problems with designing and enforcing fishing regulations in the open ocean.
  • Use on-line resources to construct maps of fisheries

What is due for Lesson 9?

The chart below provides an overview of the requirements for Lesson 9. For assignment details, refer to the lesson page noted. See the Course Schedule (located in the Resources menu to the left) for assignment due dates.

REQUIREMENT

LOCATION

SUBMITTED FOR GRADING?

Activity 1: Fisheries

page 3 Yes -   Due Apr 26

Activity 2: Empty Oceans

page 4 Yes-   Due Apr 26

Questions?

If you have any questions, please post them to our Questions? discussion forum (not e-mail), located under the Communicate tab in ANGEL. I will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.

The Secret Lives of Fishes and the Great Meal Deal

Life in the ocean: it's all about finding a good lunch spot

Contact the instructor if you have difficulty viewing this image
Source: http://www.nasaimages.org/luna/servlet/detail/nasaNAS~10~10~68509~173470:Phytoplankton-Bloom-in-the-Arabian-

 

Images show photo and false color image from a chlorophyll sensor on the OrbView-2 satellite. The satellite image shows howing high concentrations of phytoplankton in the Arabian Sea. The chlorophyll that the plants use to convert light to food tints the water green in the natural color image (top). The phytoplankton are growing in large swirls that follow the eddies and currents of the surface water. In the lower image, ocean chlorophyll concentrations are shown. Not surprisingly, concentrations appear to be highest near the coast where upwelling makes nutrients more available. NASA images courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE . See this web site for more info. [1]

 

 

Reading

  • Please review these ppt slides. [2]
  • PDF file of slides. [3]

The following are key points in the ppt slides

  • Importance of simple photosynthetic organisms (phytoplankton) to the food chain in the oceans.
  • Importance of nutients and sunlight to phytoplankton growth
  • Fish live close to their food supply, and/or, they travel huge distances for special feeding events
  • How are nutrients supplied to the photic zone?
  • What happens to all of the food (organic matter, carbon) produced in the photic zone? Is it buried as sediment at the bottom of the ocean?
  • Energy cycle of the ocean, composting, role of bacteria
  • Why are deep waters important for phytoplankton growth?
  •  
  • Good background reading for phytoplankton importance [1]

Aquaculture and the future of marine fisheries

Aquaculture

Contact the instructor if you have difficulty viewing this image
Source: http://www.agricultureinformation.com

 

Required Reading

  • Aquaculture: Should it be located offshore? (pdf file) [4]
  • Lawmakers, Enviros Maneuver in Last-Gasp Bid to Block Deepwater Aquaculture, NY Times, 3 Aug 2009 [5]

Background information. FYI

  • Organic Aquaculture, is it possible? [6] Recent work draws wide-range criticism
  • NOAA's Aquaculture program [7] A vision for the future?

Fisheries and Issues of Global Catch; Activity 1

The Ocean is vast, but its resources are finite

Empty Oceans Empty Nets       (this is an excellent movie on the subject) [8]

Contact the instructor if you have difficulty viewing this image
Source: http://www.fao.org/fishery/sofia/en

 

Reading

  • THE STATE OF WORLD FISHERIES AND AQUACULTURE [9] The definitive and most recent study of world fisheries written by the Food and Agriculture O rganization of the United Nations (FAO)

 

 

 

 

 

 

 

Activity 1: Fisheries

  • Scan/read the document from FAO and pick 4 or 5 of the most compelling plots and/or data sets. Give details about where to find them (so that others can find them in the document) and summarize, in a few sentences for each, why you chose them. Use the comments box below.
  • Respond to each of the blogs written by other students

See the grading rubric [10] for s pecifics on how this assignment will be graded.

Empty Oceans Empty Nets; Activity 2

The Ocean is vast, but its resources are finite

Empty Oceans Empty Nets

Contact the instructor if you have difficulty viewing this image
Source: Prof. D. Saffer, 2008

This photo shows the situation every morning, 365 days a year, in one of several fishmarkets in Tokyo

Visit this web site [8] and read about the problems with overfishing. This PBS documentary is a must see. You may be able to get it from your local library. If not you could buy it (it's a great thing to show to your classes). I've also collected a few youtube links with interesting shorts on related topics.

Reading

Click on the links below. I have provided some guidance about what to focus on, but these are excellent resources, so you are encouraged to read beyond my suggestions.

  • Oceans of Nothing [11] A study says overfishing will soon destroy the seafood supply. Read this first and then look at the slides by Boris Worm (next link below)
  • How loss of ocean species threatens human well-being [12] What happened to all the big fish? Slides by Boris Worm
  • Empty nets and empty stomachs [13] Clips from a television documentary about local problems with global fleets
  • Humorous commercial about a big problem involving small fish [14] You should also check out OceanLegacy.org
  • Investing in our future [15] Check out this web site for recent information on government involvement in the problem of overfishing
  • Greenpeace, Overfishing [16] Many marine ecologists think that the biggest single threat to marine ecosystems today is overfishing

Activity 2: Empty Oceans

  • Summarize the issues of overfishing in a 400 to 500 word "blog" using the comment box below. Emphasize one or more of the following: data documenting the problems, local vs. national and international solutions, creative solutions.
  • Respond to each of the blogs written by other students

See the grading rubric [10] for specifics on how this assignment will be graded.

 

Authors: Michael Arthur and Chris Marone, Department of Geosciences, College of Earth and Mineral Sciences, The Pennsylvania State University.

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Source URL: https://www.e-education.psu.edu/earth540/content/c9.html

Links:
[1] http://www.nasa.gov/centers/goddard/news/topstory/2005/plankton_elnino.html
[2] https://courseware.e-education.psu.edu/courses/earth540/priv/Earth540Life.ppt
[3] https://courseware.e-education.psu.edu/courses/earth540/priv/Earth540Life.pdf
[4] https://courseware.e-education.psu.edu/courses/earth540/Naylor.Science.ed.06.pdf
[5] https://courseware.e-education.psu.edu/courses/earth540/AqucultureLawmakers3Aug2009.html
[6] http://www.thefishsite.com/fishnews/8426/us-organic-aquaculture-draws-widerange-criticism
[7] http://aquaculture.noaa.gov/
[8] http://www.pbs.org/emptyoceans/
[9] https://courseware.e-education.psu.edu/courses/earth540/fao.2008.fisheries.pdf
[10] https://www.e-education.psu.edu/earth540/grading_rubric_problemsets
[11] https://courseware.e-education.psu.edu/courses/earth540/2006-11-13_Oceans_of_NothingTime_and_Science.pdf
[12] https://courseware.e-education.psu.edu/courses/earth540/Boris_Worm_MAR19_2007.pdf
[13] https://www.youtube.com/watch?v=b-Zhlprs_Ew
[14] https://www.youtube.com/watch?v=a2Ubw6bgMKA
[15] http://www.pewenvironment.org/our-focus/ocean-1080/fisheries-1082
[16] http://www.greenpeace.org/international/campaigns/oceans/overfishing