all sea turtle species except the Australian flatback Natator
depressus are included in the IUCN Red List as endangered
or critically endangered (IUCN, 2007). Conserving sea turtles
is particularly complex as it requires knowledge of different
aspects of the sea turtle life-cycle such as biology, breeding,
migration and foraging. As sea turtles spend more than 99%
of their lives at sea they are relatively inaccessible and
constrained largely to when females return to natal beaches
IUCN Red list, a prioritised compilation of endangered wildlife
species, can be a powerful tool for conservation planning,
management, monitoring and for placing pressure on decision-makers
and politicians, highlighting the vulnerability of endangered
Red List is widely considered to be the most objective and
authoritative system for classifying species in terms of
the risk of extinction. The IUCN aims to have the category
of every species re-evaluated every 5 years if possible,
or at least every ten years. This is done in a peer reviewed
manner through IUCN Species Survival Commission (SSC) Specialist
Groups, which are Red List Authorities responsible for a
species, group of species or specific geographic area. See
IUCN’s Marine Turtle Specialist Group: http://www.iucn-mtsg.org/
Reference and links:
Tomas, J., Aznar F., Raga, A. (2001) Feeding ecology of
the loggerhead turtle Caretta caretta in the western Mediterranean.
J. Zoology (2001) 255, 525-532.
Red Lists: http://www.iucnredlist.org/
of the Red Listing for Sea Turtles
In the review of sea turtles and IUCN Red Listing, Seminoff
and Shanker have identified some key shortcomings of the
Red Listing for the conservation of sea turtles (Seminoff
and Shanker, 2008).
A scientific or campaign tool? The influential nature
of the IUCN Red Listing Status has meant that many species
have been claimed to be on the ‘brink of extinction’
and used to fuel conservationist campaigns. This has
meant that variations between populations, regions and
abundance means that confusion has arisen over what
populations are doing well and what are in danger of
Regionally distinct populations: For a globally distributed
species such as the sea turtle needs conservation listings
need to recognize the existence of regionally distinct
populations to effectively convey extinction probabilities
Longevity: IUCN criteria for assessing over a 10-year
or 3-generation time frame. Long-lived species like
the sea turtle use the 3-generation time frame, but
with a single sea turtle generation being as much as
40 years this could mean 150 years to determine population
Flexible criteria still problematic: Additional criteria
and strategies for making status designations have included:
geographic range (Criteria B); absolute number of mature
individuals in the population (Criteria C and D) and
quantitative analysis to determine probability of extinction
in the wild (Criteria E). However these are all problematic
for applying to sea turtle status for the reasons of:
continued migrations despite potentially reduced populations,
difficulty in measuring population size, inter-annual
variability and inter-generational ‘time-bomb’
from egg harvest over multiple decades.
Shifting baselines and data deficiency: Other problems
facing sea turtle listing include the ‘shifting
baseline syndrome’ (Pauly, 1995 in Seminoff and
Shanker, 2008) which means that some populations have
been characterized as stable or increasing even if they
are depleted relative to historic levels; and data availability,
especially with historic data.
The journey is as valuable as the destination: The IUCN
Red List is highly influential and ‘policy relevant’
and the assessment process is of exceptional value.
However ‘the amassing of data from around the
world that has taken countless hours to access and organize,
and the resultant knowledge of differences among populations
is overshadowed by the single status listing’
(Seminoff and Shanker, 2008: 59).
Solutions identified by Seminoff and Shanker suggest modifying
existing IUCN Red List criteria, undertake regional assessments
and establishing a new of conservation assessment.
Seminoff, J. and Shanker, K. (2008). Marine turtles and
IUCN Red Listing: A review of the process, the pitfalls,
and novel assessment approaches. Journal of Experimental
Marine Biology and Ecology (356) pp: 52-68.
Case Study- Change Of IUCN Status For "Mediterranean"
MEDASSET Considers Change a 'Step
Backwards' for Conservation, Scientists see the IUCN Red
List Status as an objective tool
The IUCN Marine Turtle Specialist Group (MTSG) has recently
changed the IUCN Red list (World Conservation Union) status
of the green turtle in the Mediterranean from a regional
critically endangered status, to only an endangered global
listing. The IUCN Red List, a prioritised compilation of
endangered wildlife species, can be a powerful tool for
conservation planning, management, monitoring and for placing
pressure on decision-makers and politicians, highlighting
the vulnerability of endangered species. At this time there
is "insufficient and improper justification" for
the green turtle to be classified as a subpopulation within
the Mediterranean, according to listing criteria. MEDASSET
considers that this devalued status could potentially jeopardize
conservation efforts in the region.
MTSG's decision may be a step backward for green turtle
conservation in the Mediterranean as it may jeopardise regional
conservation efforts of a population estimated at only 250-500
nesting females! So far, the "critically endangered"
status of the green turtle in the Mediterranean has been
crucial for pushing the very few protection measures and
political support available, to salvage and recover the
species. To determine suitable listing for the green turtle
in the Mediterranean, appropriate documentation to meet
special IUCN subpopulation criteria is needed. Considering
that these studies take several years and IUCN listing procedures
are rather slow, by the time the process is complete there
may be no turtles left to protect! The fact that they nest
primarily in non-EU member states, restricting the influence
of strong EU Environmental legislation, further exacerbates
MEDASSET proposed that during
this 'data deficient period', the green turtle population
in the Mediterranean retain its listing with a time allowance
for research and conservation reasons, before such a sudden
devaluation takes place. The IUCN Red list has been increasingly
powerful and relevant for "concentrating minds on true
priorities", let’s hope that this devalued status
of the green turtle in the Mediterranean does not distract
from its critical conservation need.
Scientists argue that...
The IUCN must base its decisions on fact not feeling and
at present sufficient data is not available to support the
green turtle in the Mediterranean as a separate sub-population.
Genetic studies are the only way forward to determine true
listing of the species in the Mediterranean.
If the Mediterranean green turtle is listed as a subpopulation,
it could potentially affect green turtle's listing globally.
Obviously the green turtles in the Mediterranean needs far
more help than those in other parts of the world, but with
the listing change they both have an endangered status.
It works both ways - if Mediterranean greens are at a later
date declared a separate sub-population, should we consider
listing others as only vulnerable?
A system is needed that allows conservationists to prioritise
their efforts; the current system certainly needs refining!
Source: MEDASSET (2006) Change of IUCN Status for ‘Mediterranean’
green turtle. Turtle Dives newsletter. Available online: