The IUCN Red List Office recently provided comments on the draft 2011 assessment and considered that our conclusion of a Near Threatened status was not consistent with the restricted area of habitat assessment criterion used in the draft assessment. We had erred on the side of caution by concluding Near Threatened but on further reflection we have now revised the assessment given a more detailed consideration of the assessment Criterion B.

The proposed category listing of this subpopulation is now Least Concern, given the re-assessment of status according to Criterion B2 (Area of Occupancy). The revised version of the assessment is now available for download here (PDF). The changes in the revised document from the previous are highlighted.

If you are a MTSG member and would like to comment on this revised assessment, please review the document and submit any comments directly to Milani Chaloupka (m.chaloupka@uq.edu.au) by Tuesday, February 7, 2012.

Please note that the revised assessment is not considered official until it has been accepted by IUCN. We will update this site as we hear from IUCN regarding their review of the revised assessment.

UPDATE (1/30/2012): After review by IUCN, the Red List Assessment of Hawaiian green turtles has been revised and is pending re-submission. See this post for details.

The final version of a Red List Assessment of the Hawaiian subpopulation of green turtles (Chelonia mydas) was completed by Nicolas Pilcher, Milani Chaloupka, and Erin Woods and submitted by the MTSG to IUCN for consideration this week. This follows a review of the draft assessment by the entire MTSG and the Assessment Steering Committee, and multiple rounds of revision.

The proposed category listing of this subpopulation is Near Threatened, as it nearly met the threshold for classification as Vulnerable under Criterion B2 (Area of Occupancy). The final version of the assessment, as submitted to IUCN, is available for download here (PDF).

Please note that the assessment is not considered official until it has been accepted by IUCN. We will update this site as we hear from IUCN regarding their review of the assessment.

Photo by sbisson

The 11 Most Threatened Sea Turtle Populations are:

• Olive ridley turtles (Lepidochelys olivacea) in the West Indian Ocean
  • Key nesting sites: India and Oman
• Loggerhead turtles (Caretta caretta) in the Northeast Indian Ocean
• Key nesting sites: Sri Lanka, Bangladesh and Myanmar
• Olive ridley turtles  (Lepidochelys olivacea) arribada population in the Northeast Indian Ocean
• Key nesting sites: India
• Olive ridley turtles (Lepidochelys olivacea) in the Northeast Indian Ocean
• Key nesting sites: India and Sri Lanka
• Hawksbill turtles (Eretmochelys imbricata) in the Northeast Indian Ocean
• Key nesting sites: India, Sri Lanka and Bangladesh
• Hawksbill turtles (Eretmochelys imbricata) in the East Atlantic Ocean
• Key nesting sites: Congo and Sao Tome et Principe
• Loggerhead turtles (Caretta caretta) in the Northeast Atlantic Ocean
• Key nesting sites:  Cape Verde
• Hawksbill turtles (Eretmochelys imbricata) in the East Pacific Ocean
• Key nesting sites:  El Salvador, Nicaragua; Ecuador
• Leatherback turtles (Dermochelys coriacea) in the East Pacific Ocean
• Key nesting sites:  Mexico, Nicaragua and Costa Rica
• Loggerhead turtles (Caretta caretta) in the North Pacific Ocean
• Key nesting sites:  Japan
• Hawksbill turtles (Eretmochelys imbricata) in the West Pacific Ocean
• Key nesting sites: Malaysia, Indonesia and Philippines

The report was co-authored by more than 30 MTSG members from 6 continents and more than 20 countries with diverse expertise in all aspects of sea turtle biology and conservation. The work is the latest product of the MTSG’s “Burning Issues” initiative, and was supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF).

We found that four of the seven sea turtle species have populations among the world’s 11 most threatened. Almost half (five) of these populations are found in the northern Indian Ocean, specifically on nesting beaches and in waters within Exclusive Economic Zones (EEZs) of countries like India, Sri Lanka, and Bangladesh. Other areas that proved to be the most dangerous places for sea turtles were the East Pacific Ocean (from the U.S. to South America) and East Atlantic Ocean (off the coast of west Africa).

“The report confirms that India is a home to many of the most threatened sea turtles in the world,” said Dr. B. C. Choudhury, MTSG regional vice chair, head of the Department of Endangered Species Management at the Wildlife Institute of India, and a contributor to the study. “This paper is a wake –up call for the authorities to do more to protect India’s sea turtles and their habitats to ensure that they survive.“

The study also highlights the twelve healthiest sea turtle populations in the world, which are generally large populations with increasing trends under relatively low threats, as well as twelve “critical data needs” where more research is urgently needed.

“Before we conducted this study, the best we could say about sea turtles was that six of the seven sea turtle species are threatened with extinction globally,” said Dr. Bryan Wallace, MTSG regional vice chair, Director of Science for the Marine Flagship Species Program at CI, and lead author for the paper. “But this wasn’t very helpful for conservation because it didn’t help us set priorities for different populations in different regions. Sea turtles everywhere are conservation-dependent, but this framework will help us effectively target our conservation efforts around the world.”

The seven sea turtle species comprise 58 biologically defined populations, called regional management units (RMUs), as described in a publication earlier this year. To determine the most threatened RMUs, we scored traits like population size, population trends, rookery vulnerability, and genetic diversity as well as threats of fisheries bycatch, human consumption of turtles and their eggs, coastal development, pollution and pathogens, and climate change for each RMU.

“We are excited by the clarity this new study provides by identifying areas around the world that are most important for sea turtle conservation,” said Dr. Claude Gascon the Chief Science Officer and Executive Vice-President of NFWF. “This report is a guide for scientists, conservationists, policy makers, and funders to determine where conservation resources can be allocated to improve the status of these threatened populations.”

The most significant threats across all of the threatened populations are fisheries bycatch, the accidental catch of sea turtles by fishermen targeting other species, and direct harvest of turtles or their eggs for food or turtle shell material for commercial use.

“This assessment system provides a baseline status for all sea turtles from which we can gauge our progress on recovering these threatened populations in the future,” explained Roderic Mast, Co-Chair of the MTSG, CI Vice President, and one of the paper’s authors. “Through this process, we have learned a lot about what is working and what isn’t in sea turtle conservation, so now we look forward to turning the lessons learned into sound conservation strategies for sea turtles and their habitats.”

We are excited to have this publication available after several years of work by many MTSG members, and hope that it will be used to inform future investments in marine turtle conservation. We will be updating the Burning Issues section of this website with additional information and supplemental resources in the near future, so please check back soon.

A loggerhead turtle escapes from a trawl net equipped with a turtle excluder device (TED). Image courtesy of NOAA.

A study published this month (PDF available here) estimates that the number of sea turtles accidentally caught and killed in United States coastal waters has declined by an estimated 90-percent since 1990, a dramatic reduction achieved in fisheries where specific regulations have been implemented to reduce bycatch. The report, published in the scientific journal Biological Conservation, is the first attempt to make a cumulative estimate of sea turtle bycatch and mortality from interactions with U.S. fisheries.

Researchers at Duke University’s Project GloBAL (Global By-catch Assessment of Long-lived Species) and Conservation International (CI) compiled available information reported by the National Marine Fisheries Service (NMFS), the agency responsible for managing US fisheries, to estimate how many sea turtles were taken as bycatch by U.S. fishermen between 1990 and 2007. Bycatch is the accidental capture and injury of marine animals in fishing gear that are not the target catch species.

The researchers estimated that 4,600 sea turtles currently perish each year in U.S. coastal waters, but nevertheless represents a 90-percent reduction in previous death rates. The scientists credit the reduced impact on sea turtles to bycatch reduction measures implemented in many fisheries over the past 20 years, in addition to critical declines in domestic fishing effort.  Overall turtle bycatch, including all fatal and non-fatal interactions, has been reduced by roughly 60-percent.

Before measures to reduce bycatch were put in place, total sea turtle takes surpassed 300,000 annually, killing more than 70,000 of these unintended captures across more than 20 fisheries that fish in U.S. waters in the Atlantic Ocean (from the Gulf of Mexico to the border with Canada) and Pacific Ocean (along the West coast and around Hawaii). Shrimp trawls in the Gulf of Mexico and Southeastern U.S. alone accounted for up to 98% of all takes and deaths during the past two decades.

To accomplish this reduction, NMFS instituted a series of regulations and mitigation strategies in individual fisheries, which included: the use of circle hooks in longlines as well as dehooking equipment to reduce the severity of injuries to turtles; the implementation of turtle excluder devices (TEDs) in shrimp trawl nets to allow captured sea turtles the chance to escape; and time-area closures that keep fishing activities and turtles separate in places and during times that turtles are most likely to be present in highest numbers.

All six marine turtle species that occur in U.S. waters are currently categorized as Threatened or Endangered on the U.S. Endangered Species List. They include loggerheads, leatherbacks, hawksbills, olive ridleys, Kemp’s ridleys and green sea turtles. Bycatch is the most serious, acute threat to sea turtle populations around the world, and high bycatch can be indicative of unsustainable fishing practices that negatively impact the health of marine ecosystems.

“The reduction of bycatch and mortality shows important progress by NMFS, which serves as a model for reducing sea turtle bycatch in other parts of the world,” said Elena Finkbeiner, a PhD student at Duke and lead author of the paper. “Our findings show that there are effective tools available for policy makers and fishing industries to reduce sea turtle bycatch, as long as they are implemented properly and consistently.”

While these trends are encouraging, the researchers also highlighted a crucial issue still in need of improvement. Currently, sea turtles are managed on a fishery-by-fishery basis, which means that bycatch limits are set for each fishery without accounting for the overall population impacts of all the takes added together. This piecemeal view and fragmented approach leads to total allowed takes that far exceed what sea turtle populations can sustain, in part because they are affected by multiple fisheries. So although these reductions in sea turtle bycatch are important, it is still unclear whether bycatch has been reduced enough to help sea turtles recover.

“We commend the successful efforts of fishers and NMFS managers to reduce sea turtle bycatch, but there is still important work to be done,” said Dr. Bryan Wallace, a co-author on the study and Director of Science for the Marine Flagship Species Program at Conservation International and Adjunct Faculty member at Duke University. “Bycatch limits must be set unilaterally across all U.S. fisheries with overall impacts to populations in mind, much as it’s done for marine mammals. This would ensure that these bycatch reductions are successful in recovering sea turtle populations.”

The report relied on NMFS data generated largely through an on-board observer program, which places non-fishermen aboard fishing vessels to independently monitor and document fishing activities, particularly bycatch. The observer program and mitigation efforts place NMFS among the best national fisheries management agencies in the world, but researchers stress that bycatch estimates in some fisheries are highly uncertain because observer coverage is too low relative to the sheer volume of fishing taking place.

In particular, the researchers noted high uncertainty in shrimp trawl bycatch estimates due to a lack of observer coverage and inconsistent compliance with TED regulations in these fisheries. This means that actual bycatch is likely higher than what the study reported, because researchers assumed full compliance by fisheries governed by bycatch regulations.

“This paper provides a baseline to examine what is working and what can be improved in preventing sea turtle bycatch,” Finkbeiner said. “It certainly does make a strong case for the need for increased observer coverage and bycatch reporting across US fisheries.”

“The bottom line is, we have the tools and the knowledge to save these iconic but threatened animals,” Wallace said. “We just have to commit to consistently implementing these tools in fisheries in U.S. waters and around the world to promote sustainable fisheries with reduced bycatch.”

A hawksbill turtle swims off the coast of Brazil. Hawksbills are one of five marine turtle species found in Brazil. Image courtesy of TAMAR.

In order to define the actions most needed to protect Brazil’s national fauna, the conservation status of each species must be assessed to identify primary threats, sites of importance for protection, and compatibility with human activities. Such status assessments also provide a basis for the National List of Endangered Species, which, as a signatory to the Convention on Biological Diversity, the Brazilian government is obligated to maintain.

In October 2009, ICMBio (the Brazilian federal agency for biodiversity conservation) started a process to evaluate the conservation status of Brazil’s sea turtles, which was carried out in accordance with IUCN criteria for regional Red List assessments. The process included public consultation through an evaluation form that was published on the ICMBio website and sent to targeted scientific bodies and specialists throughout Brazil. Neca Marcovaldi, national technical coordinator of Projeto TAMAR and MTSG regional vice-chair for the Southwest Atlantic Region, coordinated the review process for sea turtles, and Alexsandro Santos, national manager of SITAMAR (Information System on Marine Turtles), acted as focal point for this process.

The information received through the evaluation form was compiled and used as supporting information for a workshop to develop national Red List assessments for sea turtles. The workshop was attended by members of TAMAR-ICMBio, Fundação Pró Tamar, the coordinator of the Brazilian Red List Assessment (Dr. Monica Peres from the ICMBio Department of Biodiversity), researchers, and experts on sea turtles. The resulting draft assessment was then sent to two anonymous experts in IUCN criteria for validation of this assessment (i.e. “peer review”).

The resulting evaluations of marine turtles were chosen as the subject for the first edition of BIO BRAZIL – Brazilian Biodiversity, an ICMBio electronic magazine created for the publication of the assessments. The assessments of the five sea turtle species that occur in Brazil are available through this link.

The main threats that were defined through the Red List assessments are being used to inform the development of a National Action Plan for Sea Turtles that will guide conservation activities and research in the Brazil for the next 5 years. The entire Action Plan is expected to be published in August.