Featured Research

from universities, journals, and other organizations

Recovery of Hawaiian green sea turtles still short of historic levels

Date:
May 29, 2013
Source:
Stanford University
Summary:
Hawaiian green sea turtle populations have increased in recent years, but their numbers still fall far short of historic levels. A new report suggests that calls to lift protection for this species may be premature.

A green sea turtle glides through open water near the Hawaiian Islands.
Credit: Chris Pincetich/Marine Photobank

Calls to lift protections for the iconic Hawaiian green sea turtle may be premature, according to a new study led by a Stanford researcher.

Related Articles


Although the number of Hawaiian green sea turtles has increased since 1978 when the species was listed under the U.S. Endangered Species Act, the population may still be only a fraction of historic levels, the research shows.

"It's critical to compare the animal's population level to its historic abundance, not just to recent levels," said study coauthor John N. "Jack" Kittinger, an early career fellow at Stanford's Center for Ocean Solutions (COS).

Kittinger and his collaborators compared contemporary (1973-2012) and historical (1250-1950) nesting records of Hawaiian green sea turtles from fishery logs, archeological sites, Hawaiian-language newspapers and first-hand historical accounts. The researchers also gathered current nesting data from the National Oceanic and Atmospheric Administration's green turtle field monitoring program run by its Pacific Islands Fisheries Science Center.

The work yielded extensive data sets on the occurrence, abundance, geographic distribution and harvest of sea turtles in Hawaii spanning hundreds of years.

Analysis of these records and other archival sources revealed that 80 percent of major historic green sea turtle nesting sites have disappeared and many others have shrunk greatly in size. The only remaining significant nesting site, which accounts for 90 percent of green sea turtle nesting in the Hawaiian Islands, is vulnerable to sea level rise and other threats.

"Hawaiians were able to sustainably coexist with nesting green sea turtles as recently as the early 20th century, when nesting sites could still be found on the main Hawaiian Islands," said Kittinger, a coauthor of the study who conducted much of the research before joining COS as an early career fellow.

"After traditional harvesting restrictions gave way, we see evidence for population depletion" he said. "This needs to be considered for sustainable management of the species moving forward, including a potential harvesting program should the species be delisted."

The green sea turtle is an important cultural symbol in Hawaii and performs vital marine functions such as controlling the spread of algae in coral reefs.

"Research such as this study, based on historic and socioeconomic data, adds an important perspective that has been missing from population assessments of endangered animals," said Larry Crowder, COS science director and a sea turtle expert, who was not involved in the study. "The paper shows that Hawaii's current green sea turtle population is significantly reduced from historic levels and, due to the conservative approach of these scientists, these numbers may underrepresent that decline."

The study was published online May 22 in the journal Ecography. Collaborators conducting the research included Kittinger, NOAA and the NOAA Pacific Sea Turtle Historical Ecology Working Group.


Story Source:

The above story is based on materials provided by Stanford University. The original article was written by Karen Marvin. Note: Materials may be edited for content and length.


Journal Reference:

  1. John N. Kittinger, Kyle S. Van Houtan, Loren E. McClenachan, Amanda L. Lawrence. Using historical data to assess the biogeography of population recovery. Ecography, 2013; DOI: 10.1111/j.1600-0587.2013.00245.x

Cite This Page:

Stanford University. "Recovery of Hawaiian green sea turtles still short of historic levels." ScienceDaily. ScienceDaily, 29 May 2013. <www.sciencedaily.com/releases/2013/05/130529133500.htm>.
Stanford University. (2013, May 29). Recovery of Hawaiian green sea turtles still short of historic levels. ScienceDaily. Retrieved November 20, 2014 from www.sciencedaily.com/releases/2013/05/130529133500.htm
Stanford University. "Recovery of Hawaiian green sea turtles still short of historic levels." ScienceDaily. www.sciencedaily.com/releases/2013/05/130529133500.htm (accessed November 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, November 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Your Complicated Job Might Keep Your Brain Young

Your Complicated Job Might Keep Your Brain Young

Newsy (Nov. 20, 2014) Researchers at the University of Edinburgh found the more complex your job is, the sharper your cognitive skills will likely be as you age. Video provided by Newsy
Powered by NewsLook.com
Mysterious Glow Worms Found in the Amazon

Mysterious Glow Worms Found in the Amazon

Buzz60 (Nov. 20, 2014) Wildlife photographer Jeff Cremer teamed up with entomologist Aaron Pomerantz and others to investigate a predatory glow worm found in the Amazon. Patrick Jones (@Patrick_E_Jones) explains. Video provided by Buzz60
Powered by NewsLook.com
Raw: Huge Snow Covers Buffalo Streets

Raw: Huge Snow Covers Buffalo Streets

AP (Nov. 20, 2014) A new blast of lake-effect snow roared through western New York with thunder and lightning on Thursday, raising to nearly 6 feet the three-day total in parts of the Buffalo area. (Nov. 20) Video provided by AP
Powered by NewsLook.com
Report Warns of Global Chocolate Shortage

Report Warns of Global Chocolate Shortage

Buzz60 (Nov. 20, 2014) A new report warns the world could face a 2.2-billion pound chocolate shortage within the next five years. Mike Janela (@mikejanela) explains. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins