TEACHER PAGES
What role do
plankton play in
the food web?
LESSON ONE
California Current Ecosystem
Plankton Food Web
and
the
Beth Simmons Education and Outreach Coordinator, CCE LTER, Scripps Institution of Oceanography, and Christy Millsap Rancho
Bernardo High School San Diego, California
What is a food web?
Habitats within California’s ocean ecosystems contain rich and productive marine
communities. Many of the species present here are able to exploit the rich coastal
upwelling that brings nutrients to the sunlit ocean waters at the ocean's surface. A food
chain represents one possible pathway for the transfer of energy and nutrients from
plants to herbivores to carnivores and top predators. However, most organisms eat more
than one type of prey and are fed upon by more than one type of predator. When these
multiple food chains are put together, they form a complicated web that explains the
different pathways through which energy and nutrients move within an ecosystem.
Every drop of water in the top 100
meters of the ocean contains thousands
of free-floating, single-celled microscopic
living organisms: plant-like phytoplankton
and animal-like zooplankton. Together
they fuel life in the ocean.
Plants, the “primary producers” in ecosystems,
use the sun’s energy during a process known
as photosynthesis to build raw materials
(glucose). Animals are organisms that do not
have the ability to make their own food and
therefore must consume other organisms in
order to obtain energy. The level at which an
organism consumes is referred to as a trophic
level; in other words, how far removed their
food source is from the primary producer. A
primary consumer is also referred to as an
herbivore - as they eat only plants.
A secondary consumer is an animal that feeds
on herbivores. Tertiary consumers feed on
Figure 1: An example of a marine pelagic food web. Credit: From "Fishing down marine food webs'
secondary consumers. Energy is lost as it
as an integrative concept" by Daniel Pauly (University of British Columbia, Canada), Proceedings of
moves from one trophic level to the next.
the EXPO'98 Conference on Ocean Food Webs and Economic Productivity, online at the
Community Research and Development Information Page.
This means that it takes more primary
producers to support tertiary consumers
than the primary producers needed to support their immediate consumers. This is why few ecosystems can support
trophic levels further than a quaternary or fourth-level consumer.
In order to understand how food webs are formed, it is essential to understand how species interact. In marine
ecosystems, phytoplankton hold the position of primary producers and are thus essential for the health and
maintenance of the entire marine food web.
1
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER PAGES
What role do
plankton play in
the food web?
LESSON ONE:
California Current Ecosystem
Plankton Food Web
and
the
Beth Simmons Education and Outreach Coordinator, CCE LTER, Scripps Institution of Oceanography, and Christy Millsap Rancho
Bernardo High School San Diego, California
Objective: To determine the possible effect of fewer phytoplankton in the CCE food web.
Hypothesis: Predict what might happen to an oceanic food web if phytoplankton numbers were drastically reduced.
Materials:
•
Article: Ocean warming's effect on phytoplankton: NASA satellite data show how global climate change hurts marine
food chain
•
CCE food web cards (Illustrated by Kirsten Carlson, 2010)
•
California Current Ecosystem Illustration (Illustrated by Kirsten Carlson, 2010)
Target audience: Grade 9-12 Biology, Marine Science, or Environmental Science
Time Frame: 60 min class period
CA standards addressed:
Life Science standards- 1f,1g, 6b , 6d.
Earth Science Standard 7a.
Investigation and Experimentation 1a, 1b, 1c, 1d, 1j, 1k,1m.
National Science Standards:
NS.9-12.1 SCIENCE AS INQUIRY- Abilities necessary to do scientific inquiry, understandings about scientific inquiry
NS.9-12.3 LIFE SCIENCE- Interdependence of organisms
Procedure:
Note: Before beginning, have students cut out all the species identification cards.
1. Read the article titled ”Ocean warming’s effect on phytoplankton...” As you read the article, write down any organisms
that are affected by the decline in phytoplankton abundances.
2. Use the CCE LTER marine ecosystem illustration to help you construct a food pyramid using the species identification
cards. Lay out the cards according to their trophic levels and then transfer their names onto your data sheet.
3. Label each level of the pyramid on your data sheet with the appropriate trophic level (producer, primary consumer,
secondary consumer, tertiary consumer, quaternary consumer)
4. Draw arrows to show the direction that energy would move through the food web (what eats what). (Teacher
Reference Sheet provided).
2
Ocean warming's effect on phytoplankton / NASA satellite data show
how global climate change hurts marine food chain.
December 07, 2006 / By Jane Kay, Chronicle Environment Writer
When the climate warms, there is a drop in the abundance of the ocean's phytoplankton, the tiny plants that feed krill, fish and whales,
according to scientists who say new research offers the first clues to the future of marine life under global warming.
Ocean temperatures have generally risen over the last 50 years
as the atmosphere warms. And now nine years of NASA
satellite data published today in the journal Nature show that the
growth rate and abundance of phytoplankton around the world
decreases in warm ocean years and increases in cooler ocean
years.
The findings are crucial because they show a consequence of the
changing global climate at the most fundamental level. Scientists
estimate that phytoplankton is responsible for about half of
Earth's photosynthesis, a process that removes carbon dioxide
from the atmosphere and converts it into organic carbon and
oxygen that feeds nearly every ocean ecosystem.
Fewer phytoplankton consume less carbon dioxide, aggravating a
cycle that can lead to even more warming.
Over the past decades, California scientists have linked declining
plankton numbers to El Niños and other warm-water years in
the Pacific Ocean, which set off a domino effect of fewer krill and
young fish and eventually failed reproduction of seabirds and
even deaths of seals and sea lions.
"What's amazing is this is the first time we see it on a global
scale," said Dave Siegel, professor of marine science at UC Santa
Barbara and a study author. "We have an inkling now what will
happen to the ocean's biology in future climates."
The scientists report that the relationship between warmer ocean waters and fewer plankton holds strongly for three-quarters of the
world's oceans.
Oceanic plant growth increased from 1997 to 1999 as the oceans cooled as a result of one of the strongest El Niño-to-La Niña
transitions on record, said NASA officials. Since 1999, the climate has been in a period of warming that has seen the health of ocean
plants diminish, they said.
When the climate warms, the ocean's upper layer where the phytoplankton proliferate becomes separated from the denser, colder
ocean water below in a sort of a stratification effect.
The ocean can't mix as well, and the plankton don't reach the nutrients in the deeper, colder waters that they use as a food supply.
For the first time, the NASA data set "is long enough and good enough so that we can evaluate the global links between climate and
productivity," Siegel said.
The NASA satellite data measure the oceans' color and helps scientists determine the amount of phytoplankton and the growth rates,
he said.
"We can know the amount of plants in the ocean by looking at the ocean's color. A blue ocean has no phytoplankton in it. The beautiful
tropical oceans that you see on postcards have little in it. The green ocean is chock-full of phytoplankton."
There is a consensus among the world's experts that carbon dioxide, methane and other greenhouse gases emitted from the burning
of fossil fuels have added to natural carbon dioxide levels. The carbon dioxide concentrations measured in ice cores in Antarctica are
the highest in 640,000 years.
Gene Carl Feldman, NASA scientist and a study author, said in a statement Wednesday that only by understanding how climate and life
on Earth are linked "can we realistically hope to predict how the Earth will be able to support life in the future.”
3
LESSON ONE
TEACHER REFERENCE
Hypothesis: Predict what might happen to an oceanic food web if phytoplankton abundance were drastically reduced.
Students’ predictions (on data sheet) should look something like this:
4
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
5
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
6
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
7
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
8
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
9
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
10
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
11
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER REFERENCE
LESSON ONE
12
Edited by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately