Truly Seeing Sea Turtles

Recovering Loggerhead Sea Turtles 

Kaylee Brunke 

http://nsbturtles.org

A map depicting the estimated number of loggerhead nests.
http://ecos.fws.gov/docs/recovery_plan/090116.pdf

According to national geographic, loggerhead turtles are the most abundant of all marine turtle species in U.S. The loggerheads have large heads with strong jaws and a reddish-brown shell, also known as a carapace (National Geographic). At a 36 inches long and approximately 250 pounds, the average turtle lives to be more than 50 years old (National Geographic). These organisms can move through the ocean water at speeds up to 15 miles per hour (National Geographic). Loggerheads are primarily carnivorous, typically eating jellyfish, sea snails, and barnacles, but they sometimes ingest vegetation like seaweed (National Geographic). These turtles inhabit temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans. More specifically, within the United States they nest along the coast from Texas to Virginia. Around 80% of the total loggerhead population nests in the Southeast U.S. which includes over 2400 kilometers of beaches spanning from North Carolina, South Carolina, Georgia, Florida, and Alabama (FWS). This region encompasses between 47,000 and 90,000 nests each year, but here is no data on the population size in the oceanic habitat (FWS). 

Baby loggerheads frantically making their way to the ocean.
http://cozumelcruiseexcursions.net

Loggerheads inhabit three basic ecosystems: the terrestrial zone, neritic zone, and oceanic zone. The terrestrial zone, also known as the nesting beach, is where egg laying and hatching occur. The beaches and shorelines that house these turtle nests must be in a place of high humidity that allows gas exchange for growth and development inside the eggs; the nests must also be located on a beach with suitable sand. When the eggs have fully developed, hatchlings escape from their eggs over a 1 to 3 day period, almost always at night and make their way to the surf where they will spend the next 20-30 hours swimming into the open ocean (FWS). 

A hatchling escaping from its egg.
google.com/site/20125electricsensation/sea-turtles

The nesting beach habitat is subject to several threats. Humans have a large effect in the endangerment of loggerheads when it comes to their habitat ashore. Some people illegally poach turtle eggs—though this is more common in other countries—and kill nesting females. In addition, human presence on beaches can be a problem because nesting females are at risk of interruption from laying their eggs. This disruption may include the use of flashlights or lanterns at night which deters the turtles from coming onto the sand. Also, heavy pedestrian traffic puts nests at risk from being compacted and buried by sand. 

Humans observing loggerheads are a potential threat to their habitat.
www.huffingtonpost.com/2013/09/10/sea-turtles-ignoring-humans_n_3903513.html

The neritic zone is defined from the surface to the sea floor where water depths do not exceed 200 meters, while the oceanic zone is the vast open ocean where water depths are greater than 200 meters (FWS). In the oceanic zone, turtles spend 75% of their time in the top 5 meters of the water column (FWS). 

Turtle swimming in the neritic zone.
http://www.westmorlandimages.com

Caught in a fishing net.
http://www.ryot.org

The most common threat to the neritic and oceanic zones includes trawl fisheries, specifically shrimp trawling which can be detrimental to turtle populations (FWS). Turtles become entangled in nets and often fisheries have ineffective turtle excluding devices (TEDs). Furthermore, long-line fishing typically used to capture sharks may enable swimming turtles to become caught in the hooks. Purse seines are also a continuing problem because they capture anything and everything that is in the ocean area that the net encompasses. Pollution is an issue when turtles mistake trash for food— namely plastic bags and balloons— because these items appear similar to their true prey, jellyfish. Other threats to turtles include noise pollution, climate change, oil drilling, boat strikes, and natural catastrophes. 

Caught in a long-line fishing hook.
http://news.mongabay.com

The loggerhead turtles were listed under the Endangered Species Act (ESA) on July 28, 1978, as an endangered species. Their recovery plan was finalized in 2009. However, these organisms have numerous biological constraints that make them challenging to protect against threats. These constraints include the fact that they are are very long-lived and slow growing animals that have multiple habitats and can travel across entire oceans (FWS). 

Research conservation and management for loggerhead turtles is conducted by federal, state, and local governments, as well as private organizations and individuals (FWS). On nesting beaches, in an effort to remedy the effects of humans on nests, tests are often marked and blocked off in order for pedestrians to avoid trampling them.

A sign marking loggerhead nests.
www.follybeach.com

Also, in several states, there are mandatory light ordinances to reduce hight pollution that deters turtles from coming to the shore to nest. Moreover, there is a sea turtle lighting certification program being implemented to educate any interested person about the effects of light pollution on sea turtles (FWS). In order to reduce nest predation by animals like feral hogs, raccoons, and foxes, as well as human foot traffic, nests are protected with a wire cage or plastic screen. 

Protected loggerhead nest.
www.floridasee.com

The main issue in the neritic and oceanic zones is the fact that turtles are caught as bycatch. In an effort to reduce bycatch, the National Marine Fisheries Service (NMFS) has implemented observer programs in federally and state managed fisheries to document how much by catch occurs (FWS). This way, we will be aware of the amount of turtles that are harmed in order to develop technology which can continue to prevent interactions with fisheries. A system will be developed for time and area closures where fishing will not occur. Also, further developing more effective TEDs will greatly reduce the amount of turtles caught in shrimp trawls (FWS). Something that has already been greatly effective is the prohibition of gillnets. Now, nets are required to have larger mesh sizes that turtles will be able to swim out of if they come across them. To remedy longline fishing methods, Regional Fisheries Management Organizations are beginning to adopt gear modifications in which it will be more difficult for turtles to be hooked on the lines (FWS). Finally, in an effort to reduce marine debris and pollution, the MARPOL, or marine pollution convention, is studying how to reduce pollution by large ships especially. 

Sources: http://ecos.fws.gov/docs/recovery_plan/090116.pdf
               http://animals.nationalgeographic.com/animals/reptiles/loggerhead-sea-turtle/