Readings on marine and estuarine ecology
In order to understand the structure and function of the Chesapeake Bay
ecosystem, we must first have some basic understanding of what an ecosystem
is and in particular we must understand the most important characteristics
of aquatic ecosystems. The readings in this folder begin with a chapter
("biological ocean processes") from the fourth edition (1987) of the oceanography
textbook by Gross, supplemented by excerpts from a similar chapter in the
first edition (1972) of the same textbook - because some important aspects
of marine ecology were left out in the later edition. In the first
of these two readings we learn about basic characteristics of ecosystems
and about energy flow, trophic levels, and food webs; about primary
production, including photosynthesis and chemosynthesis, and about respiration;
about limiting factors affecting primary production, including light and
nutrients; and about the fate of nutrients and of dissolved and particulate
organic matter in aquatic systems. The second selection covers organism
response to important environmental variables, including strategies to
maintain buoyancy and prevent sinking in the water column; responses to
differences between internal salt content and salt content of the surrounding
water; and responses to temperature variations.
The third selection, from a textbook by Nybakken on marine ecology,
provides information about population and community ecology. Basic
definitions are provided for terms describing different kinds of species
interactions, including competition, predation, and parasitism.
Different strategies for ensuring survival in the next generation are also
discussed, including the occurrence of larval or juvenile life stages;
and the two major categories of life history strategies, the opportunist
("r-selected") and equilibrium ("k-selected") strategies, are briefly reviewed
and compared.
The chapter from Hedeen is a nice piece of nature writing that explains
the concept of the food web by exploring the links in trophic levels from
phytoplankton to rockfish. The chapter from Day, et al. provides
detailed information on the role of detritus and of microbes in the ecosystem
- an important, perhaps even a dominant aspect which is not nearly so prominent
in the public consciousness as the roles of organisms like crabs, oysters,
and rockfish. A major part of this chapter is concerned with the role of
microbes in critical nutrient cycles. We will discuss in class what parts
of this material are most important for you to know.
Some general background on different habitats and living communities
in the Bay is provided in the general-interest EPA publication, "Chesapeake
Bay: Introduction to an Ecosystem," which is the first of the on-line documents
highlighted below. You should already have read this in the first week
of class, but this would be a good time to review it. The version linked
below is the text-only 1995 version of the document. For a pdf file with
all of the figures from the 2000 edition, go to the "Course Documents"
page and pull up the file from among those listed under the heading "Introduction".
1. Readings in pdf files:
-
Gross, M.G., 1987, Oceanography: a View of the Earth, 4th ed., Prentice-Hall,
chapter 12, "Biological Ocean Processes"
-
Gross, M.G., 1972, Oceanography: a View of the Earth, 1st ed., Prentice-Hall,
excerpts from chapter 14, "Life and the ocean"
-
Nybakken, J.W., 1988, Marine Biology: an Ecological Approach, 2nd ed.,
Harper & Row, excerpts from chapter 1, "Introduction to the Marine
Environment"
-
Hedeen, R.A., 1982, Naturalist on the Nanticoke, Tidewater Publishers,
chapter 1, "The alpha and omega of it all"
-
Day, J.W. Jr., Hall, C.A.S., Kemp, W.M., and Yanez-Arancibia, A., 1989,
Estuarine Ecology, selections from chapter 7, "Microbial ecology and organic
detritus in estuaries" and from chapter 3, "Estuarine chemistry"
2. Pages from the World Wide Web:
-
Chesapeake Bay: Introduction
to an Ecosystem
-
Estuarine
ecology - text from National Estuarine Research Reserve System (focus on
section after p.21)
-
Adaptations of
estuarine organisms
-
Intro to biological
oceanography (Iver Duedall, Florida Institute of Technology)
-
Biological oceanography
continued (Iver Duedall)
-
Chesapeake
Bay Land Margin Ecosystem Research: Trophic Interactions in Estuarine Systems
-
Secondary production:
zooplankton, benthos and nekton
-
Condition of
the mid-Atlantic estuaries - report released in December 1998
-
Nutrients
in the nation's waters - too much of a good thing?
-
Wet
Nitrogen Deposition to the Chesapeake Bay
Nutrient cycles:
Estuarine
nutrient dynamics
Animation
of the Nitrogen cycle - from Thomas Terry, University of Connecticut
Chemical
forms and transformations of nitrogen
Microbial
ecology of the Nitrogen cycle
Some basics about bacteria
