NOAA Games Quest to Nest Field Guide - Threats
Field Guide - Threats
Loggerheads face threats at nesting beaches and in the marine environment.
Threats to Loggerhead Turtles on the Nesting Beach
Beach armoring is the process of constructing a rigid structure along the shoreline. Examples of beach armoring include bulkheads, seawalls, soil retaining walls, and sandbags.
Armoring can prevent a turtle's access to upper parts of the beach/dune system where loggerheads prefer to lay their eggs and limit the amount of available nesting habitat.
In many areas of the world, sand mining (removal of beach sand for upland construction) also destroys nesting habitats.
Artificial lighting on or near the beach can prevent adult female turtles from leaving the ocean to nest.
Hatchlings have a tendency to orient toward the brightest direction, which on natural, undeveloped beaches is toward the broad open horizon of the sea. However, on developed beaches, the brightest direction is often away from the ocean and toward lighted structures. Hatchlings that are unable to find the ocean, or delayed in reaching it, are more likely to die from dehydration, exhaustion, or predation. Hatchlings lured into lighted parking lots or toward streetlights can be crushed by passing vehicles.
Human Recreational Beach Use
Humans are a big threat to nesting female turtles and their hatchlings. The use and storage of lounge chairs, cabanas, umbrellas, catamarans, and other types of recreational equipment on the beach can slow down nesting females and can trap hatchlings during their migration from the nest to the sea.
Visitors using flashlights or lighting campfires on the beach at night during the nesting season may also prevent nesting females from coming ashore and may disorient hatchlings from reaching the sea.
Heavy pedestrian traffic may compact sand over unmarked nests and cause nests to collapse which may crush the eggs.
Threats to Loggerhead Turtles in the Ocean
The primary threat to loggerhead turtle populations worldwide is accidental capture in fishing gear. Turtles can become entangled in gillnets, pound nets, and the lines associated with longline and trap/pot fishing gear. Turtles entangled in these types of fishing gear may drown or suffer serious injuries to their flippers from constriction by the lines or ropes. In addition to entangling turtles, longline gear can also hook turtles in the jaw, throat, or flippers.
Trawl nets that do not contain turtle excluder devices (TEDs) do not allow turtles to escape, causing them to drown.
Fishing dredges are extremely heavy metal frames dragged along the ocean floor. These frames can crush and entrap turtles, causing death or serious injury.
Marine turtles living in the pelagic (open ocean) environment commonly eat or become entangled in marine debris. The debris may include plastic bags, plastic pellets, balloons, and ghost (old and unused) fishing gear. Marine debris tends to accumulate in areas where the land meets the ocean, causing problems for young and nesting turtles.
Injury by boat propellers is a common cause of death for young and adult loggerhead turtles. Turtles are often found injured or dead on beaches with severe cuts to their carapace (shell) from boat propellers. Sea turtles must come to the surface to breathe, and are often difficult to see by boaters.
Some tips for boaters:
- Wear polarized sunglasses to help you see sea turtles in the water.
- If you see a sea turtle in the water, slow down and steer away from its direction of travel.
- If operating a boat in areas where sea turtles are known to be present, slow down and watch for turtles.