BIO 227:8: Bloggerhead

Loggerhead Turtle World

THE ENTIRE OCEAN!

(Caretta)

Listed threatened by:

Endangered Species Act in January 1998

But has been on the threatened species list since 1978

By: Derek Ramsey

Per BIO227 - Cal Poly SLO

Photograph Courtesy of National Geographic

Ecology of the Loggerhead

The Loggerhead is the largest of all hard-shelled turtles—leatherbacks are bigger but have soft shells. Loggerheads have massive heads, strong jaws, and a reddish-brown shell. Adult males reach about three feet in shell length and weigh about 250 pounds but large specimens of more than 1,000 pounds have been found throughout the ocean by fellow conservationists. They are primarily carnivores, feeding on jellyfish, conchs, crabs, and even fish, but will eat seaweed and sea grass occasionally. Mature females will often return, sometimes over thousands of miles, to the beach where they hatched to lay their eggs. Worldwide population numbers are unknown, but scientists studying nesting populations are seeing marked decreases despite endangered species protections.

Geographic and Population Changes

http://www.wildlifetracking.org/tracking/maps/project/22.gif

Loggerheads are highly migratory animals that can travel up to 7,500 miles, specifically females, who tend to make multiple trips between coastlines in order the observe their hatchlings. Because of this high rate of transiency, observing and recovering these turtles has become a bit of a challenge, in terms of research.. For the Pacific Loggerhead turtle, the research and recovery is focused on sea turtles that are permanently or temporarily on the U.S. coastline the majority of their life span. (unknown lifespan – but Loggerheads achieve sexual maturity around 35 years old)

Main threats and cause of listing:

shrimp trawling net

Fisheries (Incidental Take)

Loggerhead turtles are accidentally taken in several commercial and recreational fisheries. These include bottom trawls commonly used by shrimp vessels in the Gulf of California, gillnets, traps, pound nets haul seines and beach seines commonly used in inshore and coastal waters of Baja California. Forty-one loggerheads were captured incidentally by a single fisherman during 1985-1987 near Bahia de la Paz, Baja California. (ESA)

spear fishing incidental

plastic pollution

Debris (Entanglement and Ingestion)

The entanglement in and ingestion of persistent marine debris threatens the survival of loggerhead turtles in the eastern Pacific. Turtles become entangled in abandoned fishing gear (lines, ropes and nets) and cannot submerge to feed or surface to breathe; they may lose a limb or attract predators with their struggling. (ESA)

Description of Recovery Plan

Actions needed: Five primary actions are needed to achieve recovery (not in order of priority):

Reduce incidental capture of loggerheads by coastal and high seas commercial fishing operations.

Establish bilateral agreements with Japan and Mexico to support their efforts to census and monitor loggerhead populations and to minimize impacts of coastal development and fisheries on loggerhead stocks.

Identify stock home ranges using DNA analysis.

Determine population size and status (in U.S. jurisdiction) through regular aerial or on-water surveys. Identify and protect primary foraging areas for the species. (ESA)

Photo Courtesy of National Geographic

Description of alternative recovery plan proposal- "midway floating recovery station"

As a part of Derek Ramsey's architectural thesis proposal of creating a self sustaining series of islands/societies made from the trash of the Great Pacific Garbage Patch, a Loggerhead Hatchery (beach) will be integrated in order to house these species. This location happens to be directly in the path of migration for these animals. Having a fully regulated series of platforms for these taxa to lay and hatch their eggs with relatively no threat will change the decline in Loggerhead turtles fairly quickly. The "midway station" will house scientists and researches that can constantly monitor the activity of these animals and essentially protect the hatching process. Allowing access to this platform will create awareness for this species as long as it is kept to a minimum. Forbidding fisheries within a 100 mile radius will also decrease threat.