Turtles: Difference between revisions
From coraldigest
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''' Habitat ''' | ''' Habitat ''' | ||
#Fairly shallow waters inside reefs, bays, and inlets | |||
#Attracted to abundance of marine grass and algae | |||
#Nesting requires open beaches with minimal disturbance | |||
''' Life Cycle ''' | ''' Life Cycle ''' | ||
#Nesting season varies, occurs nocturnally at 2,3,4 year intervals | |||
#May lay as many as 9 clutches in a nesting season | |||
#*Clutches range from 75-200 eggs | |||
#*Incubation ranges from 45-75 days | |||
#*Temperature affects incubation range and sex of hatchlings | |||
#Strong nesting fidelity – green sea turtles | |||
'' Orientation '' | '' Orientation '' | ||
''' Diet ''' | ''' Diet ''' | ||
#Hatchlings eat a variety of plants and animals | |||
#Adults feed almost exclusively on sea-grasses and marine algae | |||
== Relationships with Humans == | == Relationships with Humans == | ||
#Hunting history | |||
#Hawksbill – endangered | |||
#Green – endangered in FL and Mexico, threatened everywhere else | |||
''' Importance in Ecosystems ''' | ''' Importance in Ecosystems ''' | ||
#Maintaining healthy seagrass beds and coral reefs | |||
#*Increase productivity and nutrient content of seagrass bladeswhen grazing | |||
#*Decreasing supply of nitrogen | |||
#*Hawksbills especially play a key role in managing the diversity of coral reefs by limiting the growth of sponges | |||
#Balancing marine food webs | |||
#Facilitating nutrient cycling | |||
''' Threats ''' | ''' Threats ''' | ||
#Desired for flesh and shell | |||
#Fishing methods | |||
#*Bycatch | |||
#*Long-lining | |||
#*Shrimp trawling | |||
#Oil spills and marine debris | |||
#*Fibropapillomatosis – tumor causing disease that can inhibit the turtle’s ability to swim, eat, and potentially cause other dangerous health problems | |||
#**Linked to environmentally disturbed ocean habitats | |||
#**Heavy pollution and high human population density | |||
#Beach Development – decreases nesting beach availability | |||
#*Turtles are habitual when it comes to nesting so removing their nesting locations is detrimental to reproduction | |||
#*Lighting – discourages females from nesting on developed beaches | |||
#*Erosion and armoring – these have affected the available space for nesting | |||
#*Use of turtle nesting habitat for leisure – discourages females from using that area for a nest – beach driving, furniture on beaches | |||
#Climate change | |||
#Predators | |||
#*Nests – raccoons, ants, and crabs | |||
#*Hatchlings – birds, crabs | |||
#*Adults – occasional shark attacks | |||
''' Conservation Efforts ''' | ''' Conservation Efforts ''' | ||
#Hard to monitor the effectiveness of conservation efforts because only nests are being observed – no idea of whole population status due to wide range and limited ability to track populations aside from nesting | |||
#US Endangered Species Act – prohibits hunting of sea turtles and reduces incidental losses from shrimp trawling and development | |||
#Turtle Excluder Devices – a grid of bars with an opening at either end of the net, catches larger animals and ejects them through the opening while still catching the smaller animals ie: shrimp | |||
== References == | == References == | ||
<references/> | <references/> |
Revision as of 22:45, 23 February 2014
Sea Turtles
General
Evolution
Distribution
Behavior and Ecology
Habitat
- Fairly shallow waters inside reefs, bays, and inlets
- Attracted to abundance of marine grass and algae
- Nesting requires open beaches with minimal disturbance
Life Cycle
- Nesting season varies, occurs nocturnally at 2,3,4 year intervals
- May lay as many as 9 clutches in a nesting season
- Clutches range from 75-200 eggs
- Incubation ranges from 45-75 days
- Temperature affects incubation range and sex of hatchlings
- Strong nesting fidelity – green sea turtles
Orientation
Diet
- Hatchlings eat a variety of plants and animals
- Adults feed almost exclusively on sea-grasses and marine algae
Relationships with Humans
- Hunting history
- Hawksbill – endangered
- Green – endangered in FL and Mexico, threatened everywhere else
Importance in Ecosystems
- Maintaining healthy seagrass beds and coral reefs
- Increase productivity and nutrient content of seagrass bladeswhen grazing
- Decreasing supply of nitrogen
- Hawksbills especially play a key role in managing the diversity of coral reefs by limiting the growth of sponges
- Balancing marine food webs
- Facilitating nutrient cycling
Threats
- Desired for flesh and shell
- Fishing methods
- Bycatch
- Long-lining
- Shrimp trawling
- Oil spills and marine debris
- Fibropapillomatosis – tumor causing disease that can inhibit the turtle’s ability to swim, eat, and potentially cause other dangerous health problems
- Linked to environmentally disturbed ocean habitats
- Heavy pollution and high human population density
- Fibropapillomatosis – tumor causing disease that can inhibit the turtle’s ability to swim, eat, and potentially cause other dangerous health problems
- Beach Development – decreases nesting beach availability
- Turtles are habitual when it comes to nesting so removing their nesting locations is detrimental to reproduction
- Lighting – discourages females from nesting on developed beaches
- Erosion and armoring – these have affected the available space for nesting
- Use of turtle nesting habitat for leisure – discourages females from using that area for a nest – beach driving, furniture on beaches
- Climate change
- Predators
- Nests – raccoons, ants, and crabs
- Hatchlings – birds, crabs
- Adults – occasional shark attacks
Conservation Efforts
- Hard to monitor the effectiveness of conservation efforts because only nests are being observed – no idea of whole population status due to wide range and limited ability to track populations aside from nesting
- US Endangered Species Act – prohibits hunting of sea turtles and reduces incidental losses from shrimp trawling and development
- Turtle Excluder Devices – a grid of bars with an opening at either end of the net, catches larger animals and ejects them through the opening while still catching the smaller animals ie: shrimp