All About Sea Turtles
What are the two life stages scientists discovered were most important to protect in order to help sea turtle populations recover?
Juvenile and adult sea turtles.
What is bycatch?
The accidental capture of animals like turtles in fishing gear meant for other species.
What are Green LED lights & what are they used for?
Small lights attached to fishing nets that help turtles see and avoid the nets.
What is the "Rate of population growth?"
The rate at which a population increases or decreases over time.
In the LED net experiment, regular nets without lights were used as this comparison group:
Control group: the group in an experiment that does not receive the treatment and is used for comparison.
What are the two types of ocean climates where sea turtles are typically found?
Tropical and temperate waters.
What was the estimated historical population of green sea turtles in the Caribbean before major human exploitation?
About 91 million turtles!
What are trawling nets?
Fishing nets that are dragged behind boats, often along the ocean floor.
What is carrying capacity?
The maximum population size that an environment can support with available resources.
What was the percentage reduction in sea turtle captures when illuminated nets were used in experiments?
About 50% fewer turtles (half!).
What's the approximate age sea turtles reach before they can reproduce?
20-30 years!
What is the estimated current population of green sea turtles in the Caribbean today?
About 300,000 turtles.
What are Gillnets?
Fishing nets that hang vertically in the water like a wall and catch fish by their gills.
What are Life Tables?
Tables used by scientists to measure survival and reproduction at different life stages in a population.
Name two marine animals whose bycatch was reduced by up to 95% when LED lights were used on nets.
Sharks and rays.
What's the approximate lifespan of many sea turtles?
About 60-80 years.
What is the estimated number of sea turtles illegally harvested worldwide between 1990 and 2020?
About 1.1 million turtles!
What are TEDs?
Turtle Excluder Device: A metal grid device installed inside shrimp trawling nets that allows turtles to escape while shrimp remain in the net.
What is Density Dependence?
When population growth changes because individuals compete for resources like food or space.
What is the measurement used in fisheries science that divides total catch by the amount of fishing effort.
Catch Per Unit Effort (CPUE)
What is Type III Survivorship?
The type of survivorship curve where many individuals die young but the few that survive live long lives.
List four major human causes of sea turtle population decline:
Poaching, habitat destruction, climate change, and fishing bycatch.
What is the percentage reduction in turtle deaths after Turtle Excluder Devices were introduced.
94% reduction!
What are Density-Independent factors?
Environmental factors such as storms or drought that affect populations regardless of population size.
What is an individual-based model?
A computer simulation that models populations by tracking individual organisms and their behavior.