Marine Ecosystems Flashcards
Ecological Disturbances
An event or force that brings about mortality to organisms and changes their spatial patterning in the ecosystems they inhabit
Disturbances can be biological or nonbiological
Fluctuation
Environmental indicators known to change over time and affect species population densities (rainfall, temperatures, seasons etc.)
Theory of Ecological Succession
The process of orderly and predictable change in a ecological community over time
Primary Succession
Occurs following the opening of a pristine habitat
(can take hundreds of years)
Secondary Succession
- Occurs in response to a disturbance
- Can reestablish an ecosystems climax communities in as few as 50 years
Intermediate Disturbance Hypothesis
- To enhance biodiversity there must be a mix of R-selected and K-selected species
- Little disturbances –> K-selected species dominate
- Too many disturbances –> R-selected species dominate
Resilience
A community that is changed by a disturbance but returns to its original state
Resistance
A community that resists change and remains stable
Alternative Stable State
Theory that suggests that multiple states can exist for one ecosystem
Results after reaching a tipping point
Regime Shift
Abrupt shift after an ecosystem does not respond (or responds only with great delay to the removal of the disturbance)
Results after reaching a tipping point
Tipping Point
Event that causes a regime shift or alternative stable state
Ecosystem Services
Good and services that we get from the ecosystem
What are the 4 different categories of ecosystem services?
- Provisioning services (food and water)
- Regulating services (flood control, disease control)
- Supporting services (nutrient recycling)
- Cultural services (spiritual and aesthetic benefits)
After an ecosystem has been disturbed what is the goal for restoration (what condition do you attempt to recreate)?
This depends on the goal you are trying to achieve
Describe the composition of coral
- 2 parts
- Animal element and plant element (zooxanthellae)
Symbiotic relationship - Temp ranges from 21 to 29 degrees C
- Grow best in waters less than 23 meters
- Zooxanthellae needs plenty of light for photosynthesis
- Base of coral = calcium carbonate, lithium etc.
Coral Bleaching
- Makes corals more vulnerable to disease
- Stunts growth
- Disrupts reproductive cycles
Island Mass Effect (IME)
- Around islands there is a higher concentration of phytoplankton that boost productivity
Positive feedback system
Threats to Reefs
- Changing water conditions (not too hot or cold)
- Temperature rise
- Pollutants
- Ocean acidification
- Physical destruction
- Fishing practices
- Overfishing
- Bleaching (loss of zooxanthellae)
- Disease
Ocean Acidification
- CO2 is increasing in earths atmosphere
- CO2 gets dissolved in earths oceans
- Results in a reduction in PH
What are the effects of ocean acidification?
Impairs the ability of marine organisms to build and maintain their calcium carbonate shells
This impacts growth, reproduction, and survival
Describe the Long-Spined Sea Urchin dilemma in the Discovery Bay Jamaica
Sea Urchins:
- Dominant grazers
- 1980s Caribbean: sea urchins begin to die off due to parasite
- Entire population reduced by ~98%
- Recovery has been slow
Describe the coral allee affect in Discovery bay Jamaica
- Coral recruitment = poor
- Reefs become dominated by algae
- Reduction in coral
- Declining coral cover = more room for algae to grow
What were the tipping points to the Jamaica Bay coral allee affect?
- Overfishing
- Nutrient runoff
- Sedimentation
- Disease outbreak
- Hurricanes
What ecosystem services do coral reefs provide?
- Protect coastlines from erosion by dissipating wave energy
- Biodiversity: provides habitat for numerous fish species
- Water quality: many corals and sponges are filter feeders
- Fisheries: fish rely on coral reef systems for food, shelter, nurseries etc.
- Tourism
- Potential source for new pharmaceuticals
