Transcript Honors Marine Biology

Honors Marine Biology
Continental Shelf Communities
Module 12
February 21, 2013
Class Challenge
Class Quiz
Module 11 Coral Reef
Question 1
What are the three physical requirements for coral
growth?
Corals need:
warm water,
a hard substrate
sunlight
… in order to grow.
Question 2
Identify these creatures as Reef Builders or Reef
inhabitants:
Soft coral: Reef Inhabitant – does not form
calcium carbonate exoskeleton.
Hard coral: Reef builder
Coralline Algae: Reef builder
Coral Grouper: Reef Inhabitant
Crabs: Reef Inhabitant
Question 3
Define and Draw:
Fringing Reef: A type of coral reef that
forms as a border along the coast.
Barrier Reef
Barrier Reef: A type of coral reef that
occurs at a distance from the coast
Atoll Reef
• Atoll: A ring of coral reef with a steep
outer slopes, enclosing a shallow lagoon.
Question 4
A.
B.
C.
D.
E.
F.
G.
H.
Tentacles
Mouth
Septa
Columella
Nematocysts
Coenosarc
Gut Cavity
Corallite
Field Trips
We have had 3 official field trips so far this
year. We will have one more that is
scheduled on April 20.
Fishing tournament held at Harts Landing
10:00am to 12:00 noon.
Continental Shelf Communities
The continental shelf is a gently sloping
area, beginning at a point near land, just
below the low-tide mark.
It continues out to the shelf break, which is
the outer edge of the continental shelf.
Ocean Basins (Part 1): Features of the
Ocean Floor (Continental Margin)
http://youtu.be/8Xpflh1187M
Virtual Field Trip: Underwater flyby of
Southern California's offshore sea floor
http://youtu.be/kTTEajWRg4Y
This area contains abundant quantities of
life. Vast fishing areas are found here.
Coral Reef communities are located on the
continental shelf.
Let’s look at life on the bottom of the
continental shelf.
Using scuba diving equipment and
underwater submersibles, scientists are
beginning to learn more about the vast
resources in this area.
Oil and mineral deposits are found here, and
nations depend upon many of the
resources in this underwater zone.
Temperature
One of the most important physical factors in
this community is temperature.
Continental shelf temperatures vary
dramatically throughout the world. In
warmer areas near the equator, there are
many more species of organisms living on
the continental shelf as compared to
colder shelf areas near the poles.
The Polar Regions
Even though there are not as many species
living on the continental shelves near the
poles, there are some interesting
organisms living there.
Sponges, seaweeds and invertebrates.
Based upon where these
organisms live, they can be divided
into three groups:
1. Benthos: Marine Organisms that live on
the sea bottom.
2. Nekton: Marine organisms that swim
strongly enough to move against the
ocean current.
3. Plankton: Marine organisms that cannot
swim strongly enough to move against
the ocean current.
Benthos
Organisms live on the bottom surface of the
continental shelf.
Nekton and Plankton
Live in the water column above the
continental shelf.
The main difference between plankton and
nekton is that Nektonic organisms have
the ability to swim against the direction of
the current while Planktonic organisms
cannot.
Subtidal
The continental shelf area is subtidal. That means
that it stays underwater regardless of the tides.
It is still affected by the currents and waves. As the
tides move in and out, strong tidal currents can
move across the region. This keeps the water
above the shelf well mixed resulting in:
1. a rich supply of nutrients,
2. relatively constant salinity and
3. temperature throughout the shelf from surface
to bottom.
Continental Shelf –
Subtidal Community
Tidal currents spread nutrients that flow from
nutrient rich rivers and estuaries into the
continental shelf. This provides more
available food for organisms that live here.
Scientists interchange the name of this area
with subtidal communities.
Soft-Bottom Shelf Communities
Continental Shelf communities can be divided into
two groups based upon the substrate of the
ocean floor.
1. Soft-bottom shelf communities
2. Hard-bottom shelf communities
The type of substrate determines what types of
organisms can populate the ocean floor.
Most are made up of soft sediments such as
sand and mud. These soft bottom subtidal
areas are frequently flat and are often
similar in appearance to the muddy
bottomed estuaries that we studied.
Infauna
Are organisms buried in the sediment and
these make up much of the life here.
They are not quickly observed but are a
major part of the ecosystem.
They feed on Detritus ie: burrowing tube
worms, sand dollars, sea cucumbers,
heart urchins and ghost shrimps.
These deposit feeders eat detritus in one of
two ways:
1. They collect the detritus with tentacles
2. They swallow the sediments and then
their digestive systems sort the detritus
from the sediments. The detritus is used
and the sediments are excreted. Just like
earthworms.
Figure 12.2
Suspension-Feeding Infauna in a Sandy
Substrate page 291
Epifauna
Are the larger creatures that can be easily seen.
Flounder and rays live on the surface of the
sandy and muddy bottoms.
Seaweeds are often part of the epifauna, but only
if they find a hard substrate to attach to.
Rocks, Shells are often covered with algae
growing on it.
Queen conch shell covered with
algae growth.
So you see there can be soft bottom
Environments that are unvegetated as well
as Vegetated.
Meiofauna
Can only be seen through a microscope. These
tiny organisms dwell in between the sediment
particles.
They either attach to individual bits of sediment or
move freely between them.
Protozoans, nematodes, small worms and
crustaceans.
Only protozoans are single celled organisms.
Sea grass communities are usually
associated with estuaries, but they are
also found in soft-bottomed shelf
communities. And are usually found in
relatively shallow and sheltered from
extreme currents and wave action.
Turtle grass is most commonly found in the
tropics and eelgrass is in temperate areas.
Figure 12.6
Sessile organisms inhabiting seagrass
Page 294
Soft-bottom Subtidal Communities
Have a larger number of species living in
them compared to soft-bottom estuaries.
Physical conditions do not change as
drastically as they do in estuaries.
Continental Shelf Communities
1. Soft-Bottomed Shelf Communities
a. Unvegetated
b. Vegetated
2. Coral reefs
3. Hard-Bottomed Shelf Communities
Hard-Bottom Shelf Communities
These are not as prevalent as soft-bottomed
communities.
They are prominent in some locations near
Anarctica.
Hard-Bottom Subtidal Communities
There are two major categories:
1. Rocky Bottomed Communities
2. Kelp Beds
The Atlantic Shelfbreak: Using robotic
vehicles to observe ocean life
http://youtu.be/v0OYJzyxAZc
Swimming Through a Natural Aquarium
http://youtu.be/qngZBYHlznQ
Lab: Subtidal Zone Predator-Prey
Relationships
February 21, 2013
Turtle-> Pen shell->phytoplankton
Turtle->stingray->shrimp->zooplankton or phytoplankton->photosynthetic
detritus
Killer whale->Fish->plankton/zooplankton
Crab-> baby sea turtles->or starfish->coral->algae or plankton
Whales-> or fish->Krill->plankton
Baracuda ->mullet or herring->shrimp->zooplankton or phytoplankton
Conch->Quahog shell->phytoplankton
Shark->Mackerel->minnows->zooplankton
Polor bears->seals->fish->shrimp->zooplankton or phytoplankton
Stingray-> starfish or sand dollar->algae or brain coral->plankton
Starfish or Sheep head->Barnacles->zooplankton->phytoplankton
Observation of Epiphytes of Sea
Grass in Subtidal Zone
February 21, 2013
To observe the Sessile organisms inhabiting Sea
Grass using a microscope.
Observations:
Spirobis – calcified worm shell
Amphipod (sand fleas)
Sea Squirts
Juvenile Fish
Homework
Take Module 11 test
Read Module 12 to page 297
OYO: 12.1 – 12.9
Study guide: define a-c questions 2-18
Quiz:
Class challenge:
• http://quizlet.com/776732/exploringcreation-with-marine-biology-module-12continental-shelf-communities-flash-cards/