OCEANOGRAPHY & MARINE SCIENCE

An extensive series utilizing many multiple
images to present a comprehensive and
integrated approach to the total spectrum
of marine biology and oceanography. Solid
science wonderfully detailed!

MARINE PRODUCTIVITY
Is the sea as productive as we think? Light and primary production, agal symbio- sis, nutrient cycles, marine food webs. 5 pgms.85 slides, many multi-image; texts.
EPSS-0775X SLIDES
$174.95

****************************************************************************************************************
SAVE OVER $52.00 ON 5 SLIDE SET BUNDLE ORDER EP #SS-0775X......$174.95
****************************************************************************************************************

LIGHT & PRIMARY PRODUCTIVITY Slides order #SS-0775S.....$49.95

Explores the ocean's photosynthetic production, all of which occurs in a limited
vertical area of the surface waters called the photic zone. All marine plants exist in the
photic zone, and all organic materials that support the ocean's living population are
produced there. 20 frames, cassette and guide. (Filmstrip order SS-0775F.....$15.00.)

CONTENT SAMPLE: 12. The oxygen method of measuring primary production is
sometimes called the light/dark bottle method. In using this method a seawater sample
containing phytoplankton is distributed between two glass bottles, one of which is clear and the
other painted black. The bottles are then incubated for a predetermined period of time.
Incubation is preferably carried out in situ, at the depth from which the samples were collected,
but this involves maintaining the research vessel stationary and is consequently expensive.
More often the light and dark bottles are incubated in a water trough on deck, and neutral density
filters are used to approximate the light conditions at the collection depth.

At the beginning and end of the incubation period the oxygen concentrations of both
bottles are measured. Photosynthesis will have occurred in the clear bottle, thereby adding
dissolved oxygen to its water. Light cannot enter the opaque bottle, so no photosynthesis will
have occurred there. In both bottles the phytoplankton (and any zooplankton contaminants) will
have carried on respiration (the reverse reaction of photosynthesis) and thereby removed oxygen
from the water.

A measurement of net photosynthesis (photosynthesis in excess of respiratory needs)
can be obtained by measuring the gain in oxygen concentration in the light bottle. Net
photosynthesis is equated with net oxygen evolved and is obtained by subtracting the oxygen
content of the water before incubation from the oxygen content of the light bottle following
incubation. A measurement of gross photosynthesis can be obtained by adding the amount of
respiratory oxygen to the net oxygen evolved. Respiratory oxygen is calculated by subtracting
the oxygen content of the dark bottle after incubation from the oxygen content of the water before
incubation. With suitable calculations both net photosynthesis and gross photosynthesis can be
expressed in units of assimilated carbon per unit of time.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MARINE PRODUCTIVITY Slides order #SS-0780S.....$42.50

Comparing coastal and landlocked waters to the open ocean, this presentation
examines primary production in the marine environment. Even though the world ocean
covers 70% of the earth's surface, it accounts for only about 1/3 of all primary production.
The open ocean is virtually a biological desert. 15 frames, cassette and guide. (Filmstrip
order SS-0780F....$15.00.)

CONTENT SAMPLE: 2. Primary production by vascular plants in marine waters
is restricted to brackish estuarine waters and along shorelines. Shown here is the eelgrass
Zostrea (upper left) that grows at the margin of the sea and land in protected bays along the
Pacific coast of the United States.

Virtually all primary production in the marine ecosystem is due to algae, especially
diatoms (upper right) and dinoflagellates. Algae are simple plants; unlike vascular plants, the
bodies (thalli) of algae are not differentiated into roots, stems and leaves. The most important
algae in the marine economy are microscopic forms that drift passively in the surface currents.
These phytoplankton are often buoyed in the seawater by oil storage materials and long
processes that extend from their cell walls. Most are unicellular, occurring singly or grouped into
colonies. The more familiar seaweeds inhabit the littoral zone where they attach to the sunlit
bottom. These multicellular algae may attain lengths of 60 m (200 ft).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MARINE FOOD WEBS Slides order #SS-0785S....$49.95

Provides a general summary of the trophic relationships in the marine
ecosystem. Discusses the importance of inorganic nitrates and phosphates to
production, and the roles of thermocline turnover, or water mixing in the aquatic energy
cycle. 20 frames, cassette and guide. (Filmstrip order SS-0785F....$15.00.)

CONTENT SAMPLE: 3. The sunlit surface waters of the ocean where plants live
is called the photic zone. The lower boundary of the photic zone is the compensation level,
where sunlight is attenuated to the point that plant photosynthesis does not exceed plant
respiration. Below the compensation level there is no net photosynthesis, and the consumers in
this euphotic zone rely on organic materials that are produced in the sunlit waters above them.

The photic zone varies in depth according to the amount of incident sunlight and the
amount of suspended materials in the water. The compensation depth may be no lower than a
few meters in turbid coastal water, but may exceed 100 m in the clearest oceanic waters. This
is relatively shallow compared to the average 4,000 m depth of the ocean as a whole. Primary
production in the ocean is thus confined to a relatively narrow volume of surface water.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MARINE NUTRIENT CYCLES Slides order #SS-0790S.....$49.95

Examines the chemical makeup of the oceans' productive waters, wherein
nearly every naturally-occurring element can be found, although most are not required by
marine organisms. Also illustrates primary productivity, its dependence on nitrates and
phosphates and the interaction of light and nutrient salts. 20 frames, cassette and guide.
(Filmstrip order SS-0790F....$15.00.)

CONTENT SAMPLE: 10. Vertical mixing can also be induced by wind-driven currents in
coastal waters. Wind stress drags the surface waters, but due to the rotation of the earth the net
transport of water is perpendicular to the direction of the wind: to the right in the northern hemi-
sphere and to the left in the southern hemisphere. Where the prevailing winds blow perpendicular
to a coastline and toward the equator the surface waters are transported offshore. In compen-
sation, subsurface waters then flow to the surface along the coast. As the surface waters are
driven offshore they are replaced by waters from 100-200 m deep.

These upwelling waters are relatively cool and rich in nutrients. Locations of such
upwelling enjoy high productivities as long as the prevailing winds maintain their direction and
intensity. Such productive waters are common along the western margins of continents, and it is
there that the world's most productive fisheries are located. Foremost among these are the
fishing grounds associated with the Humboldt Current off the coast of Peru. The productivity of
this fishery periodically crashes as the upwelling patterns are modified every seven years by
current changes, and more dramatically every thirty years or so when abnormally weak air
circulations fail to drive the surface waters offshore.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ALGAL SYMBIOSIS Slides order #SS-0805S .....$34.95

Relates algal-invertebrate associations as examples of symbiotic relationships.
Focuses on the photosynthesis and respiration which take place in the algal cells, and
examines several examples of organisms involved in metabolic transfers. The produc-
tivity and building of coral atolls is also reviewed. 10 frames, cassette and guide.
(Filmstrip order SS-0805F......$15.00.)

CONTENT SAMPLE: 3. Reef-building corals provide only one example of algal-
invertebrate associations. Representatives of eight invertebrate phyla are known to possess
autotrophic endosymbionts. The most important animal hosts include members of these phyla:
Protozoa, Porifera (sponges), Coelenterata (hydra, jellyfish, sea anemones, corals),
Platyhelminthes (flatworms), Mollusca (clams, sea slugs).

Three general types of algae are involved in these associations: green zoochlorellae,
yellow-brown zooxanthellae, blue-green cyanellae. Zoochlorellae are most common in
fresh-water associations and zooxanthellae are confined to marine invertebrates. Algal-
invertebrate associations are always aquatic and are found in both marine and fresh-water
habitats.

Paramecium bursaria houses zoochlorellae, as does the fresh-water sponge Spongilla.
Zoochlorellae are confined to the archeocytes of host sponges and each of these ameboid cells
may contain from 10 to 100 algal cells. The green sea anemone from the Pacific coast,
Anthopleura, contains zooxanthellae within its gastrodermal cells. Adults of the marine flatworm
Convoluta also contain zooxanthellae, as do certain sea slugs.

A dramatic example of an invertebrate host is the giant clam Tridacna. Zooxanthellae
are present in the blood sinuses of the brilliantly colored mantle (left). Tridacna may grow to
enormous sizes--as much as 3-4 feet across and weighing up to 1/4 ton. Purple coloration in the
mantle regulates the amount of sunlight reaching the zooxanthellae.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


~0410-023~ School of fish. photo by Charles R. Belinky, Ph.D.

Copyright (c) MCMXCVII Educational Images Ltd., Elmira, NY, USA. All rights reserved.

EDUCATIONAL IMAGES LTD.

P.O.Box 3456 Westside Station

Elmira, N.Y., USA, 14905-0456

Telephone: 800-527-4264; 607-732-1090

Fax: 607-732-1183

E-Mail: edimages@edimages.com