Lepidochelys olivacea

Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_onStatus_en_offStatus_cr_offStatus_ew_offStatus_ex_off

Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA REPTILIA TESTUDINES CHELONIIDAE

Scientific Name: Lepidochelys olivacea
Species Authority: (Eschscholtz, 1829)
Common Name(s):
English Olive Ridley, Pacific Ridley
Spanish Tortuga Golfina, Tortuga Carpintera, Tortuga Guaraguá, Tortuga Lora, Tortuga Manila, Tortuga Mulato, Tortuga Olivacea, Tortuga Parlama
French Ridley du Pacifique, Tortue Bâtarde, Tortue de Ridley, Tortue Olivâtre
Synonym(s):
Chelonia olivacea Eschscholtz, 1829

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2bd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Abreu-Grobois, A & Plotkin, P. (IUCN SSC Marine Turtle Specialist Group)
Reviewer(s): Chaloupka, M., Bolten, A., Broderick, A.C., Dobbs, K., Dutton, P., Limpus, C., Miller, D.J., Musick, J., Pritchard, P.C.H., Shanker, K. & van Dijk, P.P. (IUCN SSC Marine Turtle Red List Authority)
Justification:
Assessment procedure
In accordance with the IUCN guidelines for Red List Assessments, the focus of this evaluation has been the number of mature individuals (IUCN 2001). For Olive Ridleys, as with other sea turtle species, as it is not possible to survey mature individuals we used an index of abundance in the form of the number of annual nesting females. Although not all females breed every year (see section on Reproduction below) and males are not evaluated, this index is considered to be the most reliable estimator for long-term population trends of marine turtles since the proportion of the total number of females that nest in any given year and the sex ratio is believed to be fairly constant across time within and between subpopulations (Meylan 1982, Limpus 1996).

Direct counts of the number of nesting females (NF) are not always available so we also relied on alternative information that can be converted to NF: number of nests per season, nests/km/yr or number of protected nests per season; annual estimates of hatchling or egg production, or census estimates of nesting females from arribada rookeries. When these proxies were used, the counted units were converted to NF based on the following constants: 105 eggs/nest and 2.5 nests/season/female. Some conservation programs reported annual number of protected nests but did not include the quantity of poached or otherwise destroyed or predated nests. For these cases we extrapolated to the total number of nests based on local estimates of conservation efficiency. All conversions to NF were made under the assumptions that (a) the mean number of eggs/nest and the number of nests/female/season do not differ significantly over the timescales we have used; and (b) the effort and the coverage of the biological parameters we used are reasonably constant through the time frame evaluated. In cases where the different surveys involved different levels of coverage, explicit corrections were made and specified in the result tables.

In spite of the Olive Ridley being the most abundant sea turtle, available quantitative information is extremely scarce and unevenly distributed across regions. We thus relied on a subset of the world’s rookeries which, we assume, exhibit population trends that are representative of the population as a whole or, at least, for each of the regions. We selected 28 Index Sites (see Figure 1 and Table 1 in the attached PDF, see link below) for which reasonably long time series of quantitative data are available. They include all the largest known populations, as well as an assortment of smaller rookeries from almost all of the regions where the species is found. All sites are assumed to be demographically independent. However, although genetic data indicate a high degree of inter-rookery migration between some rookeries (e.g., Brazil-Suriname- Bowen et al. (1998); between México to Central America in the Eastern Pacific- Briseño-Dueñas (1998)) the results reflect events within an evolutionary timescale (many generations). Within the time span relevant to the assessment (two to three generations), available evidence suggests significant demographic independence between the pairs of rookeries in question (e.g., mark-recapture in Nancite and Ostional indicate the vast majority are different turtles- reviewed by Bernardo and Plotkin (2007); absence of exchange by tagged turtles and non-overlapping nesting seasons Brazil vs Suriname/French Guiana- de Silva et al. (in press); and the lack of re-colonization of depleted arribadas in Jalisco and Guerrero in México by the very large Escobilla rookery, 500 to 1,000 km distant in over four decades).

The population abundance estimates were based on raw data or on extrapolations from regressions performed on available data. As the relatively data-rich trends consistently indicated exponential trajectories we relied on these as the method of choice for extrapolations. Some data sets contained a number of trajectories across the time frames employed and in these more than one regression was employed or a combination of regressions and raw data. We have constrained our back extrapolations to time spans close to known historical events that are believed to have defined major abundance changes in order to avoid gross exaggerations with no supporting evidence. This has, however, meant that in some cases the extrapolations have only been performed back two generations (40 years) and could be considered underestimates of decline.

Uncertainties in the assessment process
Calculations based on very different datasets obtained by different workgroups, using multiple survey methods and spanning many decades are fraught with uncertainties. A number of these could be biasing our assessment. (1) Combining abundance information for individual rookeries obtained with a number of different methodologies could provide a source of error. However, we believe that the magnitude of these errors is of minor significance to the final declines estimated. (2) Because of the assessment’s requirement for quantitative information, a very small proportion of the total known rookeries were included, and some regions are not well represented. The bias this introduces is further augmented since it is most likely that rookeries having long time series of data are also the most monitored and hence the better protected. In this case the estimates of decline will be underestimated relative to the true trends for the more numerous and less well monitored/protected rookeries. This is likely the case for regions with little (Indian Ocean and Western Pacific Ocean) or no (entire Eastern Atlantic) representation in our assessment that contribute very little to our global decline values yet where reports with qualitative evidence indicate extensive population declines (reviewed by Frazier et al. 2007, Cornelius et al. 2007). Nonetheless, although ideally a global assessment should incorporate full data from all regions to derive robust evaluations, the available information on the geographic distribution of abundances suggests that the largest rookeries are concentrated in regions with good representation and thus their inclusion will not significantly affect the global results. This is reflected at the regional level and in results for non-arribada rookeries where our sample bias will probably have caused an underestimation of true decline levels. (3) The extent of extrapolations into time past is an aspect that will undoubtedly contribute to the uncertainty of the results, particularly with scarce information. We have avoided extrapolating far beyond the oldest datasets to avoid this type of errors and thus consider that our results are conservative.

Rationale for the Red List Assessment:
In spite of scarcity in historical data, information from diverse sources has made it possible to evaluate a global decline for this widely distributed species over time periods ranging from decades to 2-3 generations. Striking regional differences are observed in the estimations that undoubtedly indicate far lower survival probabilities in some of the regions than what the global results would suggest.

There was also a stark and recurring contrast between the decline estimates for subpopulations grouped according to breeding strategy- arribada or non-arribada (solitary). The global decline rate estimated from non-arribada subpopulations (-63 to -83%) reflects a widespread low conservation status for these types of subpopulations that suggests they haven’t recovered to historical (pre 1960) levels even in regions with long-term protection programs (e.g., over four decades in México) in spite generalized increments over the last decade (Márquez et al. 1998). This needs to be highlighted because rookeries with non-arribada behavior are many times more numerous than those that nest as arribadas (e.g., in México about 98% of Olive Ridley subpopulations are non-arribada). Yet, as their abundances are up to three to four orders of magnitude smaller than arribada rookeries, they have an insignificant influence on the global decline estimates. In fact, the global net decline for the Olive Ridley is driven principally by population trends in just two arribada populations, Escobilla (México) and Ostional (Costa Rica), both in the Eastern Pacific.

The global decline value estimated on the basis of estimated population reductions of the annual number of Olive Ridley nesting females at subpopulations in the Index Sites used ranged between 31 and 36% (see Table 3 in the attached PDF, see link below). As most of the back extrapolations were limited to two generations it is likely that this value is conservative.

When deciding whether to apply Red List decline criterion A1 (the causes of reduction are clearly reversible AND understood AND ceased) or A2 (the causes of reduction may not have ceased OR may not be understood OR may not be reversible) to obtain decline thresholds for the listing process three characteristics of the species’ decline need to be analyzed (SPWG 2006): (1) is the reduction reversible?, (2) are the causes of the reduction identified and understood?, and (3) have the threatening factors ceased? Since the decline estimated is driven by result from arribada rookeries, the questions need to be addressed against what is known for these types of populations. While it would appear that the elimination of large scale commercial exploitation of the Olive Ridley for leather and local consumption has allowed for the stabilization of a significant portion of rookeries, particularly in the Eastern Pacific and in particular facilitated the growth of arribada rookeries such as Escobilla and Ostional, the population growth of Mismaloya, Tlalcoyunque and Chacahua in the same region and under similar conservation circumstances remain at reduced abundances well below an arribada category. This could indicate that under some circumstances, the reduction of arribada rookeries below a certain level can make it impossible or unlikely for it to recover an arribada behavior. The major cause for the reduction in the species is thought to have been the massive commercial over-exploitations, particularly in the Eastern Pacific. Furthermore, we do not yet fully understand nor are able to manage other stressors, some intrinsic or at least due to interactions between the overcrowding of growing populations that equally provoke dramatic declines in arribadas such as that of Nancite in spite of decades of protection (Cornelius et al. 2007). Though commercial exploitation of Olive Ridleys for international markets has effectively been eliminated, at local levels significant factors continue to impact individual rookeries such as excessive egg exploitation (e.g., Isla Caña, Panama) or bycatch (such as in Orissa, India). These examples indicate that Olive Ridleys, under current circumstances, do not meet all of the conditions for A1 and hence should be evaluated under criterion A2.

Under A2, the decline estimations obtained for the Olive Ridley Turtle at a global scale correspond to the Vulnerable IUCN Red List threshold (a decline of >30% but <50%.
For further information about this species, see 11534_Lepidochelys_olivacea.pdf.
A PDF viewer such as Adobe Reader is required.
History:
1996 Endangered
1996 Endangered
1994 Endangered (Groombridge 1994)
1990 Endangered (IUCN 1990)
1988 Endangered (IUCN Conservation Monitoring Centre 1988)
1986 Endangered (IUCN Conservation Monitoring Centre 1986)

Geographic Range [top]

Range Description:The Olive Ridley sea turtle has a circumtropical distribution, with nesting occurring throughout tropical waters (except the Gulf of Mexico) and migratory circuits in tropical and some subtropical areas (Atlantic Ocean – eastern central, northeast, northwest, southeast, southwest, western central; Indian Ocean – eastern, western; Pacific Ocean – eastern central, northwest, southwest, western central) (Pritchard 1969). Nesting occurs in nearly 60 countries worldwide. Migratory movements are less well studied than other marine turtle species but are known to involve coastal waters of over 80 countries (see Table 1 in the attached PDF, see link below). With very few exceptions they are not known to move between ocean basins or to cross from one ocean border to the other. Within a region, Olive Ridleys may move between the oceanic and neritic zones (Plotkin et al. 1995, Shanker et al. 2003) or just occupy neritic waters (Pritchard 1976, Reichart 1993).
For further information about this species, see 11534_Lepidochelys_olivacea.pdf.
A PDF viewer such as Adobe Reader is required.
Countries:
Native:
Angola (Angola); Antigua and Barbuda; Australia; Bangladesh; Benin; Brazil; Brunei Darussalam; Cambodia; Cameroon; Cape Verde; Chile; Colombia; Congo; Costa Rica; Côte d'Ivoire; Cuba; Dominican Republic; Ecuador; El Salvador; Equatorial Guinea (Bioko); Eritrea; French Guiana; Gabon; Gambia; Ghana; Guadeloupe; Guatemala; Guinea; Guinea-Bissau; Guyana; Honduras; India (Andaman Is., Nicobar Is.); Indonesia; Iran, Islamic Republic of; Jamaica; Japan; Kenya; Liberia; Madagascar; Malaysia; Maldives; Martinique; Mauritania; Mexico; Micronesia, Federated States of ; Morocco; Mozambique; Myanmar; Namibia; Nicaragua; Nigeria; Oman; Pakistan; Panama; Papua New Guinea; Peru; Philippines; Puerto Rico; Sao Tomé and Principe (Sâo Tomé); Senegal; Sierra Leone; Somalia; South Africa; Sri Lanka; Sudan; Suriname; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Togo; Trinidad and Tobago; United States (Hawaiian Is.); Uruguay; Venezuela, Bolivarian Republic of (Venezuela (mainland), Venezuelan Antilles); Viet Nam; Yemen
FAO Marine Fishing Areas:
Native:
Atlantic – eastern central; Atlantic – southeast; Atlantic – southwest; Atlantic – western central; Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – southeast; Pacific – southwest; Pacific – western central
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:

For the purposes of Red List assessments, generation length is defined as the “average age of parents” (IUCN 2001). Since this information is not available from direct observation of sea turtle species we derived a comparable value from estimates of age at which 50% of the breeders are expected to have survived, using information for age at sexual maturity and adult survival rates. An important caveat is that, while it is known that different populations of the same species can attain sexual maturity at different ages (Heppell et al. 2003) and therefore different values would need to be taken into account for different regions, the information is only available for a single region and we have had to assume the estimated values are generally applicable on a global scale. The only published study on growth and age for Olive Ridleys (Zug et al. 2006) indicates a mean age at sexual maturity for North-central Pacific Ridley sea turtles of around 13 years (range of 10-18 years). We calculated the time it would take for a cohort of breeders to reach 50% of its original size from Sn =50%, where n is years since age at first reproduction, and S is annual survival. Solving for n, n = ln(0.5)/ln(S). As extensive estimates of annual survival rates for female nesters are only available from the better studied sister taxon, Lepidochelys kempii, (TEWG 2000) we used these, which have a range of 85-92% per year. Thus, n50% = 4-9 yrs and our derived average age of female Olive Ridley parents is 17-22 years. We additionally assumed that this value would be the same for male parents. For simplicity, we have used a value of 20 yrs for the species’ generation length in this assessment.

Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Habitats
Like most other sea turtles, Olive Ridleys display a complex life cycle, which requires a range of geographically separated localities and multiple habitats (Márquez 1990). Females lay their nests on coastal sandy beaches from which neonates emerge and enter the marine environment to continue their development. They remain in a pelagic phase, drifting passively with major currents that disperse far from their natal sites, with juveniles sharing some of the adults’ habitats (Kopitsky et al. 2000) until sexual maturity is reached (Musick and Limpus 1997). Reproductively active males and females migrate toward coastal zones and concentrate near nesting beaches. However, some males appear to remain in oceanic waters and mate with females en route to their nesting beaches (Plotkin et al. 1996, Kopitsky et al. 2000). Their post-breeding migrations are complex, with pathways varying annually (Plotkin 1994) and with no apparent migratory corridors, swimming hundreds or thousands of kilometers over large ocean expanses (Morreale et al. 2007), commonly within the 20°C isotherms (Márquez 1990). In the East Pacific, they are present from 30°N to 15°S and often seen within 1,200 nautical miles from shore although they have been sighted as far as 140°W (IATTC 2004). Western Atlantic Olive Ridleys appear to remain in neritic waters after breeding (Pritchard 1976, Reichart 1993).

Demographic features / Reproduction
The species displays three modes of reproduction: arribada, dispersed nesting, and mixed strategy (Bernardo and Plotkin 2007). The first mode represents a synchronous, mass nesting behaviour that may include hundreds to thousands of females over a period of days and occurs in fewer than a dozen places worldwide. The more common form of nesting is dispersed or “solitary” with no apparent synchronicity between individual events. At some localities, a mixture of these two forms of nesting can also occur. In general, individual Olive Ridleys may nest one, two or three times per season, with approximately 100–110 eggs per clutch (Pritchard and Plotkin 1995). For this assessment we have used an average number of 2.5 nests/female/season and 105 eggs/nest. In contrast to other sea turtle species, the reproductive cycle is nearly annual (over 60% of turtles nest every year; Márquez 1990). Solitary nesters oviposit on 14 day cycles whereas arribada nesters approximately every 28 days (Pritchard 1969, Kalb and Owens 1994, Kalb 1999). Kalb (1999) found that within a nesting season solitary nesters use multiple beaches for oviposition but arribada nesters display nest site fidelity. There are extreme variations in hatching rates between nesting beaches, however, in general they are much higher in solitary nesting beaches where around 80% is common and sometimes even higher (Gaos et al. 2006). It is widely recognized that survivorship is extremely low on high-density arribada nesting beaches because of density-dependent mortality (Cornelius et al. 1991) leading to hatching rates as low as 1 to 8% (Cornelius et al. 1991). Moreover, turtles return approximately every month during a discrete nesting season (three to six months) and nests that remained intact during the previous month are again at risk when new waves of turtles crawl ashore. On solitary nesting beaches, where density-dependent mortality is not a factor, hatching rates are significantly higher (Castro 1986, Gaos et al. 2006). Post-hatching survivorship is unknown and there is no information available on recruitment rates. Presumably, like other sea turtles, Olive Ridleys experience high mortality in their early life stages. Juveniles are believed to occur in similar habitats as the adults (i.e,. pelagic waters) where they forage on gelatinous prey such as jellyfish, salps and tunicates (Kopitsky et al. 2004).
Systems: Terrestrial; Marine

Threats [top]

Major Threat(s): Like other long-lived species, Olive Ridleys are prone to population declines because of slow intrinsic growth rate in combination with anthropogenic impacts. These can accumulate over a protracted development through various life stages, multiple habitats (nesting beaches, migratory routes and pelagic foraging zones) and vast geographic expanses.

Targeted exploitation
Egg harvest. Olive Ridleys and their eggs have been harvested, mostly unsustainably, worldwide. However, the current impact is difficult to evaluate because of other simultaneous factors such as incidental take in commercial fisheries. Nonetheless, there is documentation of recent egg use causing declines (Cornelius et al. 2007). From México to Colombia, Olive Ridley eggs have been and still are used for personal and commercial use (Lagueux 1989, Arauz 2000, Campbell 2007, Cornelius et al. 2007). Laws regulating turtle egg use vary among countries, and even where laws prohibit egg use, illegal use of Olive Ridley eggs is believed to be widespread because enforcement is either non-existent or insufficient. On unprotected solitary nesting beaches (most are unprotected), egg extraction often approaches 100%. Human use of turtle eggs for consumption and domestic animal consumption historically was widespread in the Indian Ocean and continues today largely wherever Ridleys nest (Cornelius et al. 2007). Egg use has been reported in India, Bangladesh, Myanmar, Sri Lanka, Andaman Islands, Pakistan and Malaysia and is believed to have caused the decline of Olive Ridleys in these countries (Cornelius et al. 2007). Even at monitored beaches a proportion of the eggs are still lost to poaching.

Directed take of adults. In the East Pacific, although Olive Ridley turtle fisheries are now closed, illegal take of adult turtles still occurs widely with an unknown level of impact. There is evidence that thousands of Olive Ridleys are still taken each year along the Pacific coast of México (Frazier et al. 2007). In the West Atlantic, the direct take of adults has diminished over time to negligible levels (Cornelius et al. 2007). In the Indian Ocean, the use of adult Olive Ridleys and their eggs for personal use has been and continues to be widespread (Frazier 1982, Frazier et al. 2007), and market-driven harvesting of eggs and females from nesting beaches are considered the greatest threat (Cornelius et al. 2007). Personal, subsistence use of adult Olive Ridley turtles is widespread worldwide (Cornelius et al. 2007, Frazier et al. 2007). Olive Ridleys and/or their eggs are used along the entire coast of West Africa (including Macaronesia) and sold in local and regional markets (Fretey 2001).

Bycatch in fisheries
The incidental capture of Olive Ridleys occurs worldwide in trawl fisheries, longline fisheries, purse seines, gill net and other net fisheries and hook and line fisheries (Frazier et al. 2007). The impact of the incidental capture of Olive Ridleys in fisheries has been well documented for some regions but not for others. In some locations where by-catch statistics are unavailable from fisheries, cause and effect has been used to implicate a fishery in the decline of Olive Ridleys. The incidental capture of Olive Ridleys in the shrimp trawl fishery in the western Atlantic, is believed to be the main cause of the significant population decline observed there since the 1970s and currently the number of Olive Ridleys by caught in trawl fisheries off the coasts of Surinam and French Guiana is believed to be approximately a couple of thousand turtles annually (Godfrey and Chevalier 2004, Frazier et al. 2007). Gillnets and other fishing methods in this region also capture Olive Ridleys incidentally but to a lesser extent than shrimp trawl fishery (Frazier et al. 2007). Bycatch in trawl fisheries off Sergipe State in Brazil is considered the most pressing threat to that population (Thomé et al. 2003). In the eastern Atlantic, the incidental capture of Olive Ridleys by commercial fisheries is thought to be a significant threat but very little systematic data is available (Frazier et al. 2007). Incidental mortality of Olive Ridleys is worst along the coast of Orissa, India with arribada Olive Ridleys gathering to nest were fishing effort is high. Every year since the early 1980s, thousands or tens of thousands of Olive Ridleys have stranded dead on the Orissa beaches, presumably as a result of incidental capture in shrimp trawls (Pandav 2000). A gill net fishery also operates in the region and contributes to the ridley mortality along this coastline. Incidental capture in fisheries is also believed to be a serious threat in the eastern Pacific (Frazier et al. 2007) where Olive Ridleys aggregate in large numbers off shore from nesting beaches (Kalb et al. 1995, Kalb 1999), but the information available is incomplete (Pritchard and Plotkin 1995, NMFS/USFWS 1998). Incidental capture of Olive Ridleys in this region has been documented in shrimp trawl fisheries, longline fisheries, purse seine fishery and gill net fisheries (Frazier et al. 2007). Incidental capture of sea turtles in shrimp trawls is a serious threat along the coast of Central America, with an estimated annual capture for all species of marine turtle exceeding 60,000 turtles, most of which are Olive Ridleys (Arauz 1996). Recent growth in the longline fisheries of this region are also a serious and growing threat to Olive Ridleys and have the potential to capture hundreds of thousands of Ridleys annually (Frazier et al., 2007). Bycatch of Olive Ridleys is high in Indonesian tuna long-lines and shrimp trawls although mortality appears to be low (WWF Indonesia, unpublished data).

Habitat impacts
Degradation, transformation and destruction of natural conditions at nesting beaches from coastal developments continue to threaten the long-term survival of many Olive Ridley rookeries. Transformation of nesting habitat comes from the construction of new aquaculture ponds, fishing harbours and tourist facilities, as well as growth of existing coastal villages which are increasing in many parts of the world within the range of the Olive Ridley, particularly along the east coast of India (Pandav and Choudhury 1999) and in some zones in coastal México to Central America (Cornelius et al. 2007). These impacts contribute stress directly through the loss of nesting habitat or indirectly through changes in the thermal profiles of the beach, increased light pollution (Witherington 1992) and sewage effluents.

Global warming has the potential to impact the habitats and ecosystems of Olive Ridley populations worldwide (Hays et al. 2003, Weishampal 2004) but the specific impacts are purely speculative at this time. Most accounts have focused on the impact of global warming on incubation temperatures of eggs, which influence the sex ratio of the embryos (Hays et al. 2003).

Diseases and predation
Extremely little is known about diseases and their effects on Olive Ridley abundance. The only disease identified in the literature for Olive Ridleys is fibropapilloma, a herpes-virus found in sea turtles nearly worldwide (Herbst 1994). The incidence of fibropapilloma is not believed to be high in Olive Ridleys but has been observed in Olive Ridleys nesting in Costa Rica (Herbst 1994) and in México (Vasconcelos et al. 2000). At some individual rookeries, the predation by wild pigs and/or feral dogs can be substantial (e.g., in the Andaman Islands; Andrews et al. 2001). Infestation of developing eggs by fly and beetle larvae can cause significant mortality of embryos. In an extremely worrying case, the beetle larvae (Omorgus suberosus fabricius) has become a plague in the world’s largest arribada rookery in Escobilla, México where it is provoking steep drops in the hatching efficiency of the clutches laid, from a typical 30% for this colony (Márquez 1990) to less than 5% in some areas (López-Reyes and Harfush 2000). When combined with the relatively low hatching rates of high-density arribada beaches and the destruction of eggs laid by previous nesters, this problem could provoke the rookery’s decline.

Conservation Actions [top]

Conservation Actions: Most of the conservation actions on behalf of the Olive Ridley at national and international levels have been based on the species’ listing under the Endangered category in the IUCN Red List. As an Appendix I species under CITES (Convention on International Trade in Endangered Species) the international trade of skins from the species, which fuelled the large scale commercial exploitation of the Olive Ridley from the 1960s into the 1980s was effectively halted. Other relevant international instruments that list the Olive Ridley as threatened and hence obligate its conservation by member states include: the Convention on Migratory Species (CMS) and the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC). CMS-promoted Memoranda of Understanding for the conservation and management of marine turtles and their habitats have been signed by the Olive Ridley’s range states in the Indian Ocean and South East Asia (known as IOSEA) as well as in other regions such as the Atlantic Coast of Africa under the Memorandum of Understanding concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa where 21 out of 26 range states participate.

On the basis of the species’ classification in the IUCN Red List or in national endangered species lists, local legislatures of range states confer protection to the Olive Ridley. Although this sanctions law-enforcement, the implementation remains patchy at the global scale because of paucity in enforcement capabilities. Successful conservation has usually relied on well-coordinated national programs in combination with local and non-governmental organizations incorporating public outreach. Statutory use and enforcement of the Turtle Excluder Devices in the shrimp trawlers has also proven critical in some areas with high levels of interaction with this fishery.

Despite the legislative efforts to protect the Olive Ridley, human impacts continue to be significant. In some areas (such as West Africa and South East Asia), extensive monitoring needs to be implemented to identify regions and stressors requiring priority actions. Bycatch and illegal take particularly from the coastal, artisanal fisheries need to be evaluated through adequate on-board observer programs and properly addressed. The beetle infestation of the Escobilla rookery must be adequately evaluated and acceptable measures of biological control of the insect need to be implemented. The impact from the increasing development of much of the range state’s coastline has to be evaluated and suitable mitigation measures implemented.

Bibliography [top]

Alava, J.J., Pritchard, P., Wyneken, J. and Valverde, H. 2007. First Documented Record of Nesting by the Olive Ridley Turtle (Lepidochelys olivacea) in Ecuador. Chelonian Conservation and Biology. 6(2): 282–285.

Alvabera, E. 2006. Revisión de la anidación de tortugas marinas en los campamentos del Centro Mexicano De La Tortuga durante el periodo 2001-2005. Paper presented at colloquium “Presencia del Centro Mexicano de la Tortuga en la Universidad Autónoma Benito Juárez de Oaxaca”. 28 pp. Oaxaca de Juárez, Oax., 22-23 May, 2006.

Amarasooriya, K.D. and Jayathilaka, M.R.A. 2002. Marine turtle nesting on the beaches of the north-western, western, and southern provinces of Sri Lanka. In: A. Mosier, A. Foley and B. Brost (eds), Proceedings of the Twentieth Annual Symposium on Sea Turtle Biology and Conservation, pp. 93-95. NOAA Tech. Memo. NMFS-SEFSC-477.

Amorocho, D., Rubio, H. and Díaz, W. 1992. Observaciones sobre el estado actual de las tortugas marinas en el Pacífico colombiano. ontribución al conocimiento de las tortugas marinas de Colomabia, pp. 155-179. Libro 4, Serie de Publicaciones Especiales del INDERENA.

Andrews, H.V., Chandi, M., Vaughan, A., Aungthong, J., Aghue, S., Johnny, S., John, S. and Naveen, S. 2006. Marine turtle status and distribution in the Andaman and Nicobar Islands after the 2004 M 9 quake and tsu-nami. Indian Ocean Turtle Newsletter 4: 3-11.

Andrews, H.V., Tripathy, A., Aghue, S., Glen, S., John, S. and Naveen, K. 2006. The status of sea turtle populations in the Andaman and Nicobar Islands. In: K. Shanker and H.V. Andrews (eds), Towards An Integrated And Collaborative Sea Turtle Conservation Programme in India: a UNEP/CMS-IOSEA Project Report, Centre for Herpetology/Madras Crocodile Bank Trust, Post Bag 4, Mamallapuram, Tamil Nadu.

Arauz, R. 2000. Diagnóstico de la Situación Actual de las Tortugas Marinas en El Salvador. Comité Nacional para la Conservación de la Tortuga Marina en El Salvador. Estrategia Nacional Para la Conservación de las Tortugas Marinas de El Salvador. Comisión Centroamericana de Ambiente y Desarrollo.

Arauz, R.M. 1996. A description of the Central American shrimp fisheries with estimates of incidental capture and mortality of sea turtles. In: J.A. Keinath and D.E. Barnard, J.A. Musick and B.A. Bell (compilers) (eds), Proceedings of the Fifteenth Annual Symposium on Sea Turtle Biology and Conservation. NOAA Technical Memorandum, NMFS-SEFSC-387.

Asrar, F.F. 1999. Decline of marine turtle nesting populations in Pakistan. Marine Turtle Newsletter 83: 13-14.

Aureggi, M., Gerosa, G. and Chantrapornsyl, S. 2004. An update of sea turtle nesting along the Andaman coast of Thailand, 1996-2000. In: M.S. Coyne, and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 98-100. NOAA Technical Memorandum NMFS-SEFSC-528.

Bacon, P. 1981. The status of sea turtle stocks management in the Western Central Atlantic. Western Central Atlantic Fishery Commission (WECAF). Study No. 7.

Balazs, G.H. and Hau, S. 1986. Geographic distribution Lepidochelys olivacea in Hawaii. Herpetological Review 17(2): 51.

Baldwin. R.M. and Al- Kiyumi, A.A. 1999. The ecology and conservation status of sea turtles of Oman. In: M. Fisher, S.A. Ghazanfar and A. Spalton (eds), The Natural History of Oman; A Festschrift for Michael Gallagher, pp. 89-98. Backhuys Publishers, Leiden.

Barbosa, C., Broderick, A. and Catry, P. 1998. Marine Turtles in the Orango National Park (Bijagós Archipelago, Guinea-Bissau). Marine Turtle Newsletter 81: 6-7.

Barnett, L.K., Emms, C., Jallow, A., Cham, A.M. and Mortimer, J.A. 2004. The distribution and conservation status of marine turtles in The Gambia, West Africa: a first assessment. Oryx 38(2): 203-208.

Bernardo, J. and Plotkin, P.T. 2007. An evolutionary perspective on the Arribada phenomenon and reproductive behavioral polymorphism of olive ridley sea turtles (Lepidochelys olivacea). In: P.T. Plotkin (ed.), Biology and Conservation of Ridley Sea Turtles. Johns Hopkins University Press, Baltimore, MD.

Beyer, K. 2002. Investigations into the Reproductive Biology and Ecology of Olive Ridley Turtles (Lepidochelys olivacea) Eschscholtz, 1829 at Old Ningo Beach, Ghana, West Africa. Thesis, University of Bremen.

Bhaskar, S. 1981. Preliminary report on the status and distribution of sea turtles in Indian waters. Indian Forester 107(11): 707-711.

Bhaskar, S. 1993. The Status and Ecology of Sea Turtles in the Andaman and Nicobar Islands. Publication ST 1/93, Centre for Herpetology, Chennai.

Bhupathy, S. and Saravanan, S. 2006. Marine turtles of Tamil Nadu. In: K. Shanker and B.C. Choudhury (eds), Marine Turtles of the Indian Subcontinent, pp. 58-67. Universities Press, Hyderabad, India.

Bowen, B.W., Clark, A.M. and Abreu-Grobois, F.A. 1998. Global phylogeography of ridley sea turtles (Lepidochelys spp.) as inferred from mitochondrial DNA sequences. Genetica 101: 179-189.

Briseño-Dueñas, R. 1998. Variación genética de la región control del ADN mitocondrial de poblaciones de la tor-tuga golfina (Lepidochelys olivacea) en el Pacífico oriental e implicaciones para su conservación. Universidad Autónoma de Sinaloa, México.

Briseño-Dueñas, R. and Abreu-Grobois, F.A. 1994. Las Tortugas Marinas y sus Playas de Anidación: Informe Final. UNAM-CONABIO.

Briseño-Dueñas, R., Madrid-Vera, J., Rios-Olmeda, D. and Trejo-Robles, J.A. 2006. Results of long term conservation in two protected area olive ridley rookeries: needs for change in strategies. Poster presented at the Twenty-sixth Annual Symposium on Sea Turtle Biology and Conservation. Crete, Greece, 2-8 April 2006.

Brito, J. 1994. Hallazgo de Lepidochelys olivacea en la costa central de Chile. Resumenes XIV Jornadas de Ciencias del Mar / I Jornada Chilena de la Salmonicultura. 23-25 de Mayo de 1994, Puerto Montt, Chile.

Brongersma, L.D. 1972. European Atlantic Turtles. Zoologische Verhandeling, Leiden 121: 1-318.

Brown, C.H. and Brown, W.M. 1982. Status of sea turtles in the southeastern Pacific: emphasis on Peru. In: K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles, pp. 235-240. Smithsonian Institution Press, Washington, D.C.

Bustard, H.R. 1976. World’s largest sea turtle rookery? Tigerpaper 3(3): 25.

Caldwell, D.K. and Erdman, D.S. 1969. Pacific ridley sea turtle, (Lepidochelys olivacea) in Puerto Rico. Bulletin of the Southern California Academy of Science 68(2): 112.

Caldwell, D.K., Rathjen, W.F. and Hsu, B.C.C. 1969. Surinam ridleys at sea. International Turtle & Tortoise Society Journal 3(1): 4-5.

Campbell, L. 2007. Understanding human use of Olive Ridleys: implications for conservation. In: P.T. Plotkin (ed.), Biology and Conservation of Ridley Sea Turtles, Johns Hopkins University Press, Baltimore, MD.

Carr, A. 1957. Notes on the zoogeography of the Atlantic sea turtles of the genus Lepidochelys. Revista de Biología Tropical 5(1): 45-61.

Casas-Andreu, G. 1978. Análisis de la anidación de las tortugas marinas del género Lepidochelys en México. Anales del Instituto de Ciencias del Mar y Limnologia 5(1): 141-158.

Castro, J.C. 1986. Contribución de las tortugas loras solitarias (Lepidochelys olivacea Eschscholtz) en el manteni-miento de las poblaciones de esta especie. Licenciatura de Tesis. Universidad de Costa Rica.

Chantrapornsyl, S. 1992. Biology and conservation olive ridley turtle (Lepidochelys olivacea, Eschscholtz) in the Andaman Sea, southern Thailand. Phuket Marine Biological Center Research Bulletin 57: 51-66.

Charuchinda, M. and Chantrapornsyl, S. 1999. Status of sea turtle conservation and research in Thailand. Report of the SEAFDEC-Asean Regional Workshop on Sea Turtle Conservation and Management. MFRDMD-SEAFDEC, Kuala Terengganu, Malaysia 26-28 July, 19991.

Chávez, G., Morera, R., Aviles, J.R., Castro, J.C. and Alvarado. M. In press. Trends of the nesting activity of the “arribadas” of the olive ridley (Lepidochelys olivacea, Eschscholtz 1829), in the Ostional National Wildlife Refuge (1971-2003). Chelonian Conservation and Biology.

Church, J. 2004. Turtle conservation in Kenya. In: M.S. Coyne and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 139-140.

Córdoba, L. 2000. Informes de trabajo. Autoridad Nacional del Ambiente. Mimeografiado.

Cornelius, S.E. 1982. Status of sea turtles along the Pacific Coast of Middle America. In: K.A. Bjorndal (ed.), The Biology and Conservation of Sea Turtles, pp. 211-219. Smithsonian Institution Press, Washington, D.C.

Cornelius, S.E., Alvarado-Ulloa, M., Castro, J.C., Mata del Valle, M. and Robinson, D.C. 1991. Management of Olive Ridley Sea Turtles (Lepidochelys olivacea) nesting at Playas Nancite and Ostional, Costa Rica. In: J.G. Robinson and K.H. Redford (eds), Neotropical Wildlife Use and Conservation, pp. 111-135. The University of Chicago Press, Chicago, IL.

Cornelius, S.E., Arauz, R., Fretey, J., Godfrey, M.H., Márquez-M., R. and Shanker, K. 2007. Effect of land-based harvest of Lepidochelys. In: P.T. Plotkin (ed.), Biology and Conservation of Ridley Sea Turtles, Johns Hopkins University Press, Baltimore, MD.

da Silva, A.C.C.D., Comin de Castilhos, J., Rocha, D.A.S., Oliveira, F. L. C., Weber, M.I. and Barata, P.C.R. 2003. Nesting biology and conservation of the olive ridley sea turtle (Lepidochelys olivacea) in the state of Sergipe, Brazil. In: J.A. Seminoff (ed.), Proceedings of the Twenty-Second Annual Symposium on Sea Turtle Biology and Conservation, pp. 89. NOAA Technical Memorandum NMFS-SEFSC-503.

da Silva, A.C.C.D., de Castilhos, J.C., Lopez, G. and Barata, P.C.R. In press. Nesting biology and conservation of the olive ridley sea turtle (Lepidochelys olivacea) in Brazil, 1991/1992 to 2002/2003. Journal of the Marine Biological Association.

Dattatri, S. and Samarajeeva, D. 1983. The status and conservation of sea turtles in Sri Lanka. A project of the Sea Turtle Rescue Fund. Center for Environmental Education, Washington, D.C.

Dermawan, A. 2002. Marine turtle management and conservation in Indonesia. In: I. Kinan (ed.), Proceedings of the Western Pacific Sea Turtle Cooperative Research and Management Workshop, pp. 67-75. Western Pacific Regional Fishery Management Council, Honolulu, Hawaii.

De Silva, A. 2006. Marine turtles of Sri Lanka: A historic account. In: K. Shanker and B.C. Choudhury (eds), Marine Turtles of the Indian Subcontinent, pp. 188–199. Universities Press, Hyderabad, India.

Doussou Bodjrenou, J., Montcho, J. and Sagbo, P. 2004. Challenges and prospects for sea turtle conservation in Benin, West Africa. In: M.S. Coyne and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 120-122.

Evans, K.E. and Vargas, A.R. 1998. Sea turtle egg commercialization in Isla de Cañas, Panama. In: R. Byles and Y. Fernandez (eds), Proceedings of the Sixteenth Annual Symposium on Sea Turtle Biology and Conservation, pp. 45. NOAA Technical Memorandum, NMFS-SEFSC-412.

Falanruw, M.V.C., Mccoy, M. and Namlug. 1975. Occurrence of Ridley sea turtles in the Western Caroline Islands. Micronesica 11(1): 151-152.

FAO. 1974. India: A Preliminary Survey of the Prospects for Crocodile Farming (Based on the Works of Dr H. R. Bustard). FAO, Rome.

Frazier, J. 1976. Sea turtles in Tanzania. Tanzania Notes and Records 77-78: 11-14.

Frazier, J. 1984. Las tortugas marinas en el Océano Atlántio Sur Occidental. Asoc. Herp. Arg. Sér. Difulg. 2: 2-21.

Frazier, J., Arauz, R., Chevalier, J., Formia, A., Fretey, J., Godfrey, M.H., Márquez-M., R., Pandav, B. and Shanker, K. 2007. Human-turtle interactions at sea. In: P.T. Plotkin (ed.), Biology and Conservation of Ridley Sea Turtles., Johns Hopkins University Press, Baltimore, MD.

Frazier, J.G. 1975. Marine turtles of the Western Indian Ocean. Oryx 13(2): 164-175.

Frazier, J.G. 1980. Exploitation of marine turtles in the Indian Ocean. Human Ecology 8: 329-370.

Frazier, J.G. 1982. Status of the sea turtles in the Central Western Indian Ocean. Biology and Conservation of Sea Turtles in the Indian Ocean. Smithsonian Institution, Washington, D.C.

Fretey, J. 1989. Reproduction de la tortue olivâtre (Lepidochelys olivacea) en Guyane française pendant la saison 1987. Nature Guyanaise 1: 8-13.

Fretey, J. 1999. Repartition des tortues du genre Lepidochelys Fitzinger, 1843. I. L'Atlantique ouest. Biogeographica 75(3): 97-117.

Fretey, J. 2001. Biology and conservation of marine turtles of the Atlantic Coast of Africa. CMS Technical Series Publication No. 6. UNEP/CMS Secretariat, Bonn, Germany, 429 pp.

Fretey, J. and Lescure, J. 1999. Sur la présence de Lepidochelys olivacea (Eschscholtz, 1829) (Chelonia, Cheloniidae) dans les Antilles françaises. Bulletin de la Société Herpétologique de France 90: 41-49.

Fretey, J., Formia, A., Tomas, J., Dontaine, J-F., Billes, A. and Angoni, H. 2004. Presence, nesting and conservation of Lepidochelys olivacea in the Gulf of Guinea. In: M.S. Coyne and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 172. NOAA Technical Memorandum NMFS-SEFSC-528.

Fritts, T.H. 1981. Marine turtles of the Galapagos Islands and adjacent areas of the eastern Pacific on the basis of observations made by J.R. Slevin 1905-1906. Journal of Herpetology 15(3): 293-301.

Fuller, J.E., Eckert, K.L. and Richardson, J.I. 1992. WIDECAST Sea Turtle Recovery Action Plan for Antigua and Barbuda. In: K.L. Eckert (ed.), CEP Technical Report No. 16. UNEP Caribbean Environment Programme, Kingston, Jamaica.

Gaos, A.R., Yañez, I.L. and Arauz, R.M. 2006. Sea turtle conservation and research on the Pacific coast of Costa Rica. Technical Report. Programa Restauración de Tortugas Marinas.

Godfrey, M. and Chevalier, J. 2004. The status of olive ridley sea turtles in the west Atlantic. Unpublished report to the Marine Turtle Specialist Group of the SSC/IUCN.

Gomez, E.D. 1980. A review of the literature on marine turtles in the Philippines. Philippines Journal of Biology 9(1): 95-99.

Gomez, J., Sory, B. and Mamadou, K. 2003. A preliminary survey of sea turtles in the Ivory Coast. In: J.A. Seminoff, (ed.), Proceedings of the Twenty-Second Annual Symposium on Sea Turtle Biology and Conservation, pp. 146. NOAA Technical Memorandum NMFS-SEFSC-503.

Green, D. and Ortiz-Crespo, F. 1982. Status of sea turtle populations in the Central Eastern Pacific. In: K.A. Bjorndal (ed.), The Biology and Conservation of Sea Turtles, pp. 221-233. Smithsonian Institution Press, Washington, D.C.

Gyan, N. 1987. National Report prepared for the second Western Atlantic Turtle Symposium, Mayagüez, Puerto Rico, October 1987.

Halim, M.H., Silalahi, S. and Sugarjito, J. 2001. Conservation and utilization trend of marine turtles in Indonesia. Tigerpaper 28(4): 10-16.

Hamann, M., Chu The Cuong, Nguyen Duy Hong, Pham Thuoc and Bui Thi Thuhien. 2006. Distribution and abundance of marine turtles in the Socialist Republic of Viet Nam. Biodiversity and Conservation 15: 3703-3720.

Harris, A. 1994. Species review the olive ridley. In: R. James (ed.), Proceedings of the Australian Marine Turtle Conservation Workshop held at Sea World Nara Resort, Gold Coast, 14-17 November 1990, pp. 63-67. Queensland Department of Environment and Heritage and Australian Nature Conservation Agency.

Hasbún, C.R. and Vásquez, M. 1999. Sea turtles of El Salvador. Marine Turtle Newsletter 85: 7-9.

Hays, G.C., Broderick, A.C., Glen, F. and Godley, B.J. 2003. Climate change and sea turtles: a 150-year reconstruction of incubation temperatures at a major marine turtle rookery. Global Change Biology 9(4): 642-646.

Heppell, S.S., Snover M.L. and Crowder L.B. 2003. Sea turtle population ecology. In: P. Lutz, J.A. Musick and J. Wyneken (eds), The Biology of Sea Turtles, pp. 275-306. CRC Marine Science Series. CRC Press, Boca Raton, Florida.

Herbst, L.H. 1994. Fibropapillomatosis of marine turtles. Annual Review of Fish Diseases 4: 389-425.

Hewavisenthi, S. 1990. Exploitation of marine turtles in Sri Lanka: historic background and their present status. Marine Turtle Newsletter 48: 14-19.

Higginson, J. 1989. Sea turtles in Guatemala: threats and conservation efforts. Marine Turtle Newsletter 45: 1-5.

Higginson, J. and Orantes, R. 1987. Manejo de Tortugas Marinas. Universidad de San Carlos, Guatemala.

Hoinsoude, G.S., Bowessidjaou, J.E., Kokouvi, G.A., Iroko, F. and Fretey, J. 2003. Plan for sea turtle conservation in Togo. In: J.A. Seminoff (ed.), Proceedings of the Twenty-Second Annual Symposium on Sea Turtle Biology and Conservation, pp. 117. NOAA Technical Memorandum NMFS-SEFSC-503.

Honarvar, S. and van den Berghe, E. In press. Monitoring olive ridley turtles (Lepidochelys olivaeacea) on the Pacific coast of Nicaragua. 25th Annual Symposium on Sea Turtle Biology and Conservation, 2005.

Hope, R. 2000. Egg harvesting of the olive ridley marine turtle (Lepidochelys olivacea) along the Pacific Coast of Nicaragua and Costa Rica; an arribada sustainability analysis. MA in the Faculty of Economic and Social Studies, University of Manchester, England.

Houck, W.J. and Joseph, J.G. 1958. A northern record for the Pacific ridley, Lepidochelys olivacea. Copeia 1958: 219-220.

Hubbs, C.L. 1977. First record of mating ridley turtles in California, with notes on commensals, characters and systematics. California Fish and Game 63(4): 263-267.

Hughes, D.A. and Richard, J.D. 1974. The nesting of the Pacific Ridley Turtle Lepidochelys olivacea on Playa Nancite Costa Rica. Marine Biology 24(2): 97-107.

Hughes, G.R. 1972. The olive ridley sea turtle (Lepidochelys olivacea) in southeast Africa. Biological Conservation 4: 128-134.

Hurtado, M. 1981. Marine turtles recaptured in Ecuadorian waters. Boletín Informativo Instituto Nacional De Pesca Guayaquil, Ecuador 2(5): 18-23.

IATTC. 2004. Inter-American Tropical Tuna Commission (IATTC) working group on bycatch. Review of the status of sea turtle stocks in the Eastern Pacific. 4th Meeting Kobe (Japan) 14-16 January 2004, Document BYC-4-04.

Islam, M.Z. 2002. Marine turtle nesting at St. Martin’s Island, Bangladesh. Marine Turtle Newsletter 96: 19-21.

Islam, Z. 1998. Establishing Marine Turtle Hatchery in Saint Martins Island, Bangladesh. In: Centre for Advanced Research in Natural Resources & Management (CARINAM); 1998 (ed.), Proceedings of the 4th Asia-Pacific Environmental NGOs Conference. Singapore, 26-27 November, 1998.

IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. Species Survival Commision. IUCN, Gland, Switzerland and Cambridge, UK.

IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org. (Accessed: 5 October 2008).

Juarez, R. and Muccio, C. 1997. Sea Turtle Conservation in Guatemala. Marine Turtle Newsletter 77: 15-17.

Kabraji, A.M. and Firdous, F. 1984. Conservation of Turtles in Hawkesbay and Sandspit, Pakistan. World Wildlife Fund Project 1451, pp. 51. World Wildlife Fund International and Sind Wildlife Management Board, Karachi; 1984.

Kalb, H.J. 1999. Behavior and physiology of solitary and arribada nesting olive ridley sea turtles (Lepidochelys olivacea) during the internesting period. Ph.D. dissertation, Texas A&M University, College Station, TX.

Kalb, H.J. and Owens, D.W. 1994. Differences between solitary and arribada nesting olive ridley females during the internesting period. In: K.A. Bjorndal, A.B. Bolten, D.A. Johnson and P.J. Eliazar (eds), Proceedings of the Fourteenth Annual Symposium on Sea Turtle Biology and Conservation, pp. 68. NOAA Technical Memorandum, NMFS-SEFSC-351.

Kalb, H., Valverde, R.A. and Owens, D. 1995. What is the reproductive patch of the olive ridley sea turtle? In: J.I. Richardson and T.H. Richardson (eds), Proceedings of the Twelfth Annual Workshop on Sea Turtle Biology and Conservation, pp. 57-60. NOAA Technical Memorandum, NMFS-SEFSC-361.

Kamezaki, N. 1999. Natural History Notes: a stuffed olive ridley, Lepidochelys olivacea, found in Ujung Pandang, Sulawesi Island. Umigame Newsletter of Japan 40: 17.

Kami, H.G. 1997. First record of the Olive Ridley Turtle, Lepidochelys olivacea, in Iranian coastal waters (Testudines, Cheloniidae). Zoology in the Middle East 15: 67-70.

Kapurusinghe, T. 2006. Present status of marine turtles in Sri Lanka. In: N.J. Pilcher (ed.), Proceedings of the Twenty-Third Annual Symposium on Sea Turtle Biology and Conservation, pp. 59. NOAA Technical Memorandum NMFS-SEFSC-536.

Kar, C.S. 2001. Review of threats to sea turtles in Orissa. In: K. Shanker and B.C. Choudhury (eds), Proceedings of the National Workshop for the Development of a National Sea Turtle Conservation Action Plan, Bhubaneshwar, Orissa, pp. 15–19.

Kar, C.S. and Bhaskar, S. 1982. Status of sea turtles in the Eastern Indian Ocean. In: K.A. Bjorndal (ed.) Biology and Conservation of Sea Turtles, pp. 365-372. Smithsonian Institution Press, Washington, D.C.

Kopitsky, K.L., Pitman, R.L. and Dutton, P.H. 2004. Aspects of olive ridley feeding ecology in the eastern tropical Pacific. In: M.S. Coyne and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 217. NOAA Technical Memorandum, NMFS-SEFSC-528.

Kopitsky, K., Pitman, R.L. and Plotkin, P.T. 2000. Investigations on at-sea mating and reproductive status of olive ridleys, Lepidochelys olivacea, captured in the eastern tropical Pacific. In: H.J. Kalb and T. Wibbels (eds), Proceedings of the Nineteenth Annual Symposium on Sea Turtle Biology and Conservation, pp. 160-162. NOAA Technical Memorandum, NMFS-SEFSC-443.

Kosal, Mao. 2004. Biodiversity of Cambodia’s wetlands. In: M. Torell, A.M. Salamanca and B.D. Ratner (eds), Wetlands Management in Cambodia: Socioeconomic, Ecological, and Policy Perspectives. World-Fish Center Technical Report 64.

Lagueux, C.J. 1989. Olive Ridley (Lepidochelys olivacea) Nesting in the Gulf of Fonseca and the Commercialization of its Eggs in Honduras. University of Florida, Gainesville, Florida.

Lagueux, C.J. 1991. Economic analysis of sea turtle eggs in a coastal community on the Pacific coast of Honduras. In: J.G. Robinson and K.H. Redford (eds), Neotropical Wildlife Use and Conservation, pp. 136-144. The University of Chicago Press, Chicago.

Liew, Hock-Chark. 2002. Status of marine turtle conservation and research in Malaysia. In: I. Kinan (ed.), Proceedings of the Western Pacific Sea Turtle Cooperative Research and Management Workshop, pp. 51-56. February 5-8, 2002, Honolulu, Hawaii, USA.

Limpus, C.J. 1975. The Pacific Ridley, Lepidochelys olivacea (Eschscholtz) and other sea turtles in northeastern Australia. Herpetologica 31(4): 444-445.

Limpus, C.J. 1995. Global overview of the status of marine turtles: a 1995 viewpoint. In: K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles, Revised Edition, Smithsonian Institution Press, Washington, D.C.

Limpus, C.J. 1996. Myths, reality, and limitations of green turtle census data. In: J.A. Keinath, D.A. Barnard, J.A. Musick and B.A. Bell (compilers) Proceedings of the Fifteenth Annual Workshop on Sea Turtle Biology and Conservation, pp. 170-173. NOAA Technical Memorandum NMFS-SEFSC-387.

Limpus, C.J. 2001. Report to 3rd Indian Ocean South East Asia (IOSEA) meeting. Manila, Phillippines.

Limpus, C.J., Miller, J.D. and Fleay, A. 1981. The Olive Ridley Turtle, Lepidochelys olivacea, recorded from South Queensland. Herpetofauna 12(2): 2-3.

Limpus, C.J. unpublished. A Biological Review of Australian Marine Turtles IV. Olive Ridley Turtle, Lepidochelys olivacea (Eschscholtz).

López-Reyes, E. and Harfush, M. 2000. Determination of the percentage of olive ridley (Lepidochelys olivacea) in-situ nests that are affected by beetles at Escobilla, beach, México. In: A. Mosier, A. Foley and B. Brost (eds), Proceedings of the Twentieth Annual Symposium on Sea Turtle Biology and Conservation, pp. p. 83: 369.

Marcovaldi, M.A. and Marcovaldi, G.G. 1987. Projeto Tartaruga marinha. Areas de desova, época de reprodução, técnicas de preservação. B. FBCN, Rio de Janeiro.

Márquez, R., Jiménez, M.C., Carrasco, M.A. and Villanueva, N.A. 1998. Comentarios acerca de las tendencias po-blacionales de las tortugas marinas del género Lepidochelys después de la veda total de 1990. Oceánides 13(1): 41-62.

Márquez, R., Villanueva, A. and Peñaflores, C. 1976. Sinopsis de datos biologicos sobre la tortuga golfina, Lepidochelys olivacea (Eschscholtz, 1829). Instituto Nacional De Pesca, México, INP/52 Sinopsis sobre la Pesca.

Martínez, L.M. 2000. Ecologia de anidacion de la tortuga golfina (Lepidochelys olivacea) en la Playa de La Cuevita, Costa Pacifica Chocoana, Colombia, en 1998. Actualidades Biológicas Medellin 22(73): 131-143.

Martinez, L.M. and Paez, V.P. 2000. Nesting ecology of the olive ridley turtle (Lepidochelys olivacea) at La Cuevita, Chocoan Pacific coast, Colombia, in 1998. Actualidades Biologicas Medellin 22(73): 131-143.

Martínez, P., Gutierrez, C. and Arauz, R. 1998. Nesting biology of the olive ridley sea turtle (Lepidochelys olivacea) in La Flor Wildlife Refuge, Rivas, Nicaragua. In: S.P. Epperly and J. Braun (eds), Proceedings of the Seventeenth Annual Sea Turtle Symposium, pp. 228.

Maxwell, F.D. 1911. Reports on inland and sea fisheries in the Thongwa, Myaungmya, and Bassein districts and the turtle banks of the Irrawaddy division. Rangoon. Government Printing Office 57 pp. As cited in Groombridge, B. and Luxmoore, R. 1989. The green turtle and hawksbill (Reptilia: Cheloniidae): world status, exploitation and trade. Secretariat of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, Lausanne, Switzerland.

Meylan, A.B. 1982. Estimation of population size in sea turtles. In: K.A. Bjorndal (ed.) Biology and Conservation of Sea Turtles, pp. 135-138. Revised Edition. Smithsonian Institution Press. Washington, D.C.

Minarik, C.J. 1985. Olive Ridleys of Honduras. Marine Turtle Newsletter 33: 3-4.

Moncada, F., Rodríguez, A.M. Márquez, R. and Carrillo, E. 2000. Report of the Olive Ridley Turtle (Lepidochelys olivacea) in Cuban Waters. Marine Turtle Newsletter 90: 13-15.

Montoya, A.E. 1969. Programas de investigación y conservación de las tortugas marinas en México. Proceedings of the Working Meeting of Marine Turtle Specialists: 34-53. IUCN at Morges, Switzerland on 10-13 March.

Morreale, S.J., Plotkin, P.T., Shaver, D.J. and Kalb, H.J. 2007. Adult migration and habitat utilization. In: P.T. Plotkin (ed.), Biology and Conservation of Ridley Sea Turtles, Johns Hopkins University Press, Baltimore, MD.

Muccio, C. 1998. Informe Nacional Sobre El Estado De La Conservacion De Tortugas Marinas En Guatemala. Asociación Rescate y Conservación de Vida Silvestre (ARCAS). Unpublished report, 25 pp + annexes.

Musick, J.A. and Limpus, C.J. 1997. Habitat utilization and migration in juvenile sea turtles. In: P.L. Lutz and J.A. Musick (eds) The Biology of Sea Turtles, pp. 137-164. CRC Press, Boca Raton, Florida.

National Marine Fisheries Service and U.S. Fish and Wildlife Service. 1998. Recovery plans for U.S. Pacific populations of the olive ridley sea turtle (Lepidochelys olivacea). NMFS Silver Spring, MD.

Nowak, R.M. 1974. Status of the green turtle, loggerhead and olive ridley turtle. Report to the U.S. Office of Endangered Species.

Pandav, B. 2000. Conservation and Management of Olive Ridley Sea Turtles on the Orissa Coast. PhD Thesis, Utkal University, Bhubaneshwar, India.

Pandav, B. and Choudhury, B.C. 1999. An update on mortality of Olive ridley sea turtle in Orissa, India. Marine Turtle Newsletter 83: 10-12.

Peñaflores-Salazar, C., Vasconcelos-Pérez, J., Albavera-Padilla, E. and Jiménez Quiroz, M.C. 2001. Especies sujetas a protección especial. Tortuga golfina. In: M.A. Cisneros, L.F. Beléndez, E. Zárate, M.T. Gaspar, L.C. López, C. Saucedo and J. Tovar (eds), Sustentabilidad y Pesca Responsable en México. Evaluación y Manejo: 1999-2000, pp. 1001-1021. Instituto Nacional de la Pesca/SEMARNAT. México.

Pilcher, N.J. 2001. Marine turtles: How bad is good news? Report to UNESCO, December 2000, Paris.

Pilcher, N., Mahmud, S,.Howe, S., Teclemariam, Y., Weldeyohannes, S., Mengsu, T. and Giotom, M. 2006. An update on Eritrea’s marine turtle programme and first record of olive ridley turtle nesting in the Red Sea. Marine Turtle Newsletter 111: 16.

Plotkin, P.T. 1994. Migratory and reproductive behavior of the olive ridley turtle Lepidochelys olivacea (Eschscholtz, 1829), in the eastern Pacific Ocean. Texas A&M University, College Station, TX.

Plotkin, P.T., Byles, R.A., Rostal, D.C. and D.W. Owens. 1995. Independent vs. socially facilitated migrations of the olive ridley, Lepidochelys olivacea. Marine Biology 122: 137-143.

Plotkin, P.T., D.W. Owens, R.A. Byles, and R. Patterson. 1996. Departure of male olive ridley turtles (Lepidochelys olivacea) from a nearshore breeding ground. Herpetologica 52(1): 1-7.

Pritchard, P.C.H. 1969. Studies of the Systematics and Reproductive Cycles of the Genus Lepidochelys. Ph.D. dissertation, University of Florida, FL.

Pritchard, P.C.H. 1976. Post nesting movements of marine turtles (Cheloniidae and Dermochelyidae) tagged in the Guianas. Copeia 1976(4): 749-754.

Pritchard, P.C.H. 1979. Encyclopedia of Turtles. T.F.H Publications, Inc. LTD, Neptune,NJ.

Pritchard, P.C.H. and Plotkin, P.T. 1995. Olive Ridley Sea Turtle. Status Reviews for Sea Turtles Listed under the Endangered Species Act of 1973. National Marine Fisheries Service, St. Petersburg, FL.

Pritchard, P.C.H. and Trebbau, T. 1984. The Turtles of Venezuela. Society for the Study of Reptiles and Amphibians. Oxford, Ohio.

Putrawidjaja, M. 2000. Marine turtles in Irian Jaya, Indonesia. Marine Turtle Newsletter 90: 8-10.

Qureshi, M.T. 2006. Sea turtles in Pakistan. In: K. Shanker and B.C. Choudhury (eds), Marine Turtles of the Indian Subcontinent, pp. 217–224. Universities Press, Hyderabad, India.

Rashid, S.M.A. and Islam, M.Z. 2006. Status and conservation of marine turtles in Bangladesh. In: K. Shanker and B.C. Choudhury (eds), Marine Turtles of the Indian Subcontinent, pp. 200–216. University Press, Hyderabad, India.

Rashid, S.M.A. and I. Zahirul. 1998. Establishing marine turtle hatchery in Saint Martins Island, Bangladesh. Proceedings of the 4th Asia-Pacific Environmental NGOs Conference. 26-27 November, 1998, Singapore. Centre for Advanced Research in Natural Resources & Management (CARINAM).

Reichart, H.A. 1993. Synopsis of biological data on the olive ridley sea turtle Lepidochelys olivacea (Eschscholtz 1829) in the western Atlantic. NOAA Technical Memorandum NMFS-SEFSC-336.

Reichart, H.A. and Fretey, J. 1993. WIDECAST Sea Turtle Recovery Action Plan for Suriname. CEP Technical Report, No. 24. UNEP Caribbean Environment Programme. Kingston, Jamaica. In: P.T. Plotkin, (ed.) 1995. National Marine Fisheries Service and U.S. Fish and Wildlife Service Status Reviews for Sea Turtles Listed under the Endangered Species Act of 1973. National Marine Fisheries Service, Silver Spring, Maryland.

Ríos-Olmeda, D. 2005. Base de Datos (1975-2005). Centro de Protección y Conservación de Tortugas Marinas El Verde Camacho.Mazatlán, Sinaloa. Programa Nacional de Tortugas Marinas, Comisión Nacional de Areas Naturales Protegidas (CONANP-SEMARNAT). México.

Ross, J.P. and Barwani, M.A. 1982. Review of sea turtles in the Arabian area 3. In: K.A. Bjorndal (ed.) Biology and Conservation of Sea Turtles, pp. 372-38. Smithsonian Institution Press, Washington, D.C.

Salm, R.V., Jensen, R.A.C. and Papastavrou, V.A. 1993. Marine Fauna of Oman: Cetaceans, Turtles, Seabirds and Shallow Water Corals. IUCN, Gland, Switzerland.

Sarker, S. 2004. Sea turtle nesting, threat to survival and conservation efforts in Bangladesh. In: M.S. Coyne and R.D. Clark (eds), Proceedings of the Twenty-First Annual Symposium on Sea Turtle Biology and Conservation, pp. 307-308. NOAA Technical Memorandum NMFS-SEFSC-528.

Schulz, J. P. 1975. Sea turtles nesting in Surinam. Zoologische Verhandelingen 143: 1–143.

Shanker, K. 2003. Thirty years of sea turtle conservation on the Madras coast: A review. Kachhapa 8: 16–19.

Shanker, K. and Choudhury, B.C. 2006. Marine Turtles of the Indian Subcontinent. Universities Press, Hyderabad, India.

Shanker, K. and Pilcher, N.J. 2003. Marine turtle conservation in South and Southeast Asia: Hopeless cause of cause for hope? Marine Turtle Newsletter 100: 43–51.

Shanker, K., Pandav, B. and Choudhury, B.C. 2003. An assessment of the olive ridley turtle (Lepidochelys olivacea) nesting population in Orissa, India. Biological Conservation 115: 149-160.

Siaffa, D.D., Aruna, E. and Fretey, J. 2003. Presence of sea turtles in Sierra Leone (West Africa). In: J.A. Seminoff (ed.), Proceedings of the Twenty-Second Annual Symposium on Sea Turtle Biology and Conservation, pp. 285. NOAA Technical Memorandum NMFS-SEFSC-503.

Solís, D.S., Orrego, C.M., Blanco-Segura, R.V., Harfush-Meléndez, M.R., Albavera-Padilla, E.O. and Valverde, R.A. 2007. Estimating arribada size: going global. Presented at the 27th Annual Symposium on Sea Turtle Conservation and Biology. Myrtle Beach, South Carolina, 22-28 February, 2007.

Spring, C.S. 1979. Status of marine turtle populations in Papua New Guinea. In: K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles, pp. 281-289. Smithsonian Institution Press, Washington, D.C.

Spring, C.S. and Gwyther, J. 1999. Stomach contents of an Olive Ridley Turtle (Lepidochelys olivacea) from the Gulf of Papua, Papua New Guinea. Chelonian Conservation and Biology 3(3): 516–517.

Standards and Petitions Working Group. 2006. Guidelines for Using the IUCN Red List Categories and Criteria: Version 6.1. Prepared by the Standards and Petitions Working Group for the IUCN SSC Biodiversity Assessments Sub-Committee in July 2006. Available at: http://app.iucn.org/webfiles/doc/SSC/RedList/RedListGuidelines.pdf.

Sunderraj, S.F.W., Joshua, J. and Kumar,V.V. 2006. Sea turtles and their nesting habitats in Gujarat. In: K. Shanker and B.C. Choudhury (eds), Marine Turtles of the Indian Subcontinent, pp. 156-169. Universities Press, Hyderabad, India.

Suwelo, I.S. 1999. Olive ridley turtle records from south Banyuwangi, East Java. Marine Turtle Newsletter 85: 9.

Sybesma, J. and Hoetjes, P.C. 1992. First record of the olive ridley and of nesting by the loggerhead turtle in Cura-çao. Carribean Journal of Science 28(1-2): 103-104.

Thomé, J.C.A., Marcovaldi, M.A., dei Marcovaldi, G.G., Bellini, C., Gallo, B.M.G., Lima, E.H.S.M., da Silva, A.C.C.D., Sales, G. and Barata, P.C.R. 2003. An overview of Projeto TAMAR-IBAMA’s activities in relation to the incidental capture of sea turtles in the Brazilian fisheries. In: J.A. Seminoff (ed.), Proceedings of the Twenty-second Annual Symposium on Sea Turtle Biology and Conservation, pp. 119-120. NOAA Technical Memorandum NMFS-SEFSC, 503.

Thorbjarnarson, J.B., Platt, S.G. and Khaing, S.T. 2000. Sea Turtles in Myanmar: Past and Present. Marine Turtle Newsletter 88: 10-11.

Tisen, O. B. and Bali, J. 2002. Current status of marine turtle conservation programmes in Sarawak, Malaysia. In: A. Mosier, A. Foley and B. Brost (eds), Proceedings of the Twentieth Annual Symposium on Sea Turtle Biology and Conservation, pp. 12-14. NOAA Technical Memorandum NMFS-SEFSC-477.

Tripathy, B., Shanker, K. and Choudhury, B.C. 2003. Important nesting habitats of olive ridley turtles (Lepidochelys olivacea) along the Andhra Pradesh coast of eastern India. Oryx 37(4): 454-463.

Turtle Expert Working Group. 2000. Assessment Update for the Kemp’s Ridley and Loggerhead Sea Turtle Populations in the Western North Atlantic. NOAA Technical Memorandum NMFS-SEFSC-444.

Valverde, R. A., Cornelius, S. E. and Mo, C. L. 1998. Decline of the olive ridley sea turtle (Lepidochelys olivacea) nesting assemblage at Nancite Beach, Santa Rosa National Park, Costa Rica. Chelonian Conservation and Biology 3(1): 58–63.

Vasconcelos, J., Albavera, E., Lopez, E.M., Hernandez, P. and Peñaflores, C. 2000. First assessment on tumors incidence in nesting females of olive ridley sea turtle (Lepidochelys olivacea) at La Escobilla Beach, Oaxaca, México. In: F.A. Abreu-Grobois, R. Briseño-Dueñas, R. Márquez and L. Sarti (eds), Proceedings of the Eighteenth International Sea Turtle Symposium, pp. 276-278. NOAA Technical Memorandum, NMFS-SEFSC-436.

Villa Guzmán, J. 1980. Pesquería de Tortugas Marinas en el Estado de Jalisco. Tesis Profesional. Facultad de Ciencias, Universidad Nacional Autónoma de México, México.

Walczak, P.S. 1979. The status of marine turtles in the waters of the Yemen Arab Republic. British Journal of Herpetology 5(12): 851-853.

Weishampel, J.F., Bagley, D.A. and Ehrhart, L.M. 2004. Earlier nesting by loggerhead sea turtles following sea surface warming. Global Change Biology 10(8): 1424-1427.

Whiting, S.D. 1997. Observations of a nesting olive ridley turtle in the Northern Territory. Herpetofauna 27(2): 39-42.

Witherington, B.E. 1992. Behavioral responses of nesting sea turtles to artificial lighting. Herpetologica 48: 31-39.

Zug, G.R., Chaloupka, M. and Balazs, G.H. 2006. Age and growth in olive ridley sea turtles (Lepidochelys olivacea) from the North-central Pacific: a skeletochronological analysis. Marine Ecology 27: 263-270.


Citation: Abreu-Grobois, A & Plotkin, P. (IUCN SSC Marine Turtle Specialist Group) 2008. Lepidochelys olivacea. In: The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 18 December 2014.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided