Ecological Relationships
Warmup
• Describe some of the ecological relationships
that you saw in the Mt. St. Helens slideshow.
Relationships between living things
• How might two individuals from different
species interact?
– +,+
– +,0
– +,– Predation
– Competition
• What is a niche?
• Tiger Shark and loggerhead turtle interacting
in the waters near the Bahamas.
– Make a prediction about the relationship between
these two animals
– Video Clip 1
http://www.pbs.org/wnet/nature/lessons/symbiotic
-strategies/video-segments-the-secret-world-ofsharks-and-rays/1496/
• Look at your worksheet. Make a prediction
about the relationship between each of the
remaining pairs of animals.
• Video clips 2 and 3
http://www.pbs.org/wnet/nature/lessons/symbi
otic-strategies/video-segments-the-secretworld-of-sharks-and-rays/1496/
• What type of symbiotic relationship was NOT
seen in these video clips?
• Parasitism = symbiotic relationship which
provides a gain for one species and loss for the
other
– Different from predation
• Prolonged
• Does not result in death of the host (usually)
– Can you name any parasitic relationships?
Plasmodium
• Protozoan that causes malaria
– TWO host species
• Mosquito is not the parasite-it is a vector
• Life cycle of a Malaria Parasite
http://malaria.wellcome.ac.uk/node40036.html
• These ecological relationships (predation,
competition, mutualism, commensalism,
parasitism), have evolved over long periods of
time between species that coexist
– Even those detrimental to some species are
important in maintaining balance
• Threats to stability of ecosystems can occur
when dramatic events or shifts in behavior
disrupt the balance
Collapse of Sharks
• An example of an ecological relationship that
has been disrupted
• How has the relationship between humans
and sharks changed over time?
Clip 4
http://www.pbs.org/wnet/nature/lessons/symbi
otic-strategies/video-segments-the-secretworld-of-sharks-and-rays/1496/
Sharks in our Future
• How can balance be restored?
• How is the following strategy helping to solve
the problem?
Clip 5
http://www.pbs.org/wnet/nature/lessons/symbi
otic-strategies/video-segments-the-secretworld-of-sharks-and-rays/1496/
Homework
• Symbiotic Relationships Worksheet