Recovery Plan for U.S. Pacific Populations

of the

U.S. Department of Commerce

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

U.S. Department of the Interior

U.S. Fish and Wildlife Service

Olive RidleyTurtle

(Lepidochelys olivacea)
Cover Photograph Courtesy of Robert L. Pitman

RECOVERY PLAN FOR U.S. PACIFIC POPULATIONS OF THE 

Recovery plans delineate reasonable actions which are believed to be required to recover

and/or protect the species. Plans are prepared by the National Marine Fisheries Service

(NMFS) and the U.S. Fish and Wildlife Service ( FWS), and sometimes with the assistance of

recovery teams, contractors, State agencies and others. Objectives will only be attained and

funds expended contingently upon appropriations, priorities and other budgetary constraints. 

Recovery plans do not necessarily represent the views nor the official positions or approvals of

any individuals or agencies, other than those of NMFS and the FWS which were involved in

the plan formulation. They represent the official positions of NMFS and the FWS only after

they have been approved by the Assistant Administrator for Fisheries or the Regional Director. 

Approved recovery plans are subject to modification as dictated by new findings, changes in

species status and the completion of recovery tasks.

Literature citations should read as follows:

National Marine Fisheries Service and U.S. Fish and Wildlife Service. 1998. Recovery Plan

for U.S. Pacific Populations of the Olive Ridley Turtle (Lepidochelys olivacea). 

National Marine Fisheries Service, Silver Spring, MD.

Additional copies of this plan may be purchased from:

Fish and Wildlife Reference Service

5430 Grosvenor Lane

Suite 110

Bethesda, Maryland 20814

(301)492-6403 or 

1-800-582-3421

The fee for the plan varies depending on the number of pages of the plan.
i

TABLE OF CONTENTS

(Olive ridley)

PREFACE ................................................................ iii

ACKNOWLEDGMENTS ..................................................... iv

LIST OF ABBREVIATIONS .................................................... v

EXECUTIVE SUMMARY .................................................... vi

I. INTRODUCTION .......................................................... 1

A. Geographic Scope .................................................. 1

B. Historical and Cultural Background ..................................... 4

C. Taxonomy ........................................................ 5

D. Description ........................................................ 5

E. Population Distribution and Size ....................................... 6

Nesting Grounds ................................................ 6

Insular and Pelagic Range ......................................... 8

F. Status ............................................................ 9

G. Biological Characteristics ............................................. 9

Migration and Movements ......................................... 9

Foraging Biology and Diet ........................................ 10

Growth ....................................................... 11

Reproduction .................................................. 11

Offshore Behavior .............................................. 13

Health Status .................................................. 13

H. Threats ......................................................... 14

Pacific Synopsis ............................................... 14

Regional Summaries ............................................ 14

U.S. West Coast ......................................... 14

Hawaii ................................................. 15

American Samoa ......................................... 15

Guam .................................................. 15

Republic of Palau ......................................... 15

Commonwealth of the Northern Mariana Islands (CNMI) ........... 15

Republic of the Marshall Islands (RMI) ......................... 15

Federated States of Micronesia (FSM) ......................... 15

General Threat Information ....................................... 17

Nesting Environment ...................................... 17

1. Directed Take .................................... 17

2. Increased Human Presence ......................... 17

3. Coastal Construction .............................. 17

4. Nest Predation ................................... 18

5. Beach Erosion ................................... 18

6. Artificial Lighting .................................. 18

 7. Beach Mining .................................... 18
ii

 8. Vehicular Driving on Beaches ....................... 18

 9. Exotic Vegetation ................................. 19

10. Beach Cleaning ................................. 19

11. Beach Replenishment ............................ 19

Marine Environment ....................................... 19

12. Directed Take .................................. 19

13. Natural Disasters ................................ 19

14. Disease and Parasites ............................ 20

15. Algae, Seagrass, and Reef Degradation .............. 20

16. Environmental Contaminants ....................... 20

17. Debris (Entanglement and Ingestion) ................ 20

18. Fisheries (Incidental Take) ......................... 20

19. Predation ...................................... 21

20. Boat Collisions .................................. 21

21. Marina and Dock Development ..................... 21

22. Dredging ...................................... 21

23. Dynamite “Fishing” ............................... 21

24. Oil Exploration and Development ................... 21

25. Power Plant Entrapment .......................... 22

26. Construction Blasting ............................. 22

I. Conservation Accomplishments ....................................... 23

II. RECOVERY ............................................................ 24

A. Recovery Objectives ................................................ 24

B. Step Down Outline and Narrative for Recovery ........................... 25

III. REFERENCES CITED ................................................... 37

IV. IMPLEMENTATION SCHEDULE ............................................ 43
iii

PREFACE

The National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (FWS)

share responsibilities at the Federal level for the research, management, and recovery of Pacific

marine turtle populations under U.S. jurisdiction. To accomplish the drafting of this recovery plan,

NMFS appointed a team of professional biologists experienced with marine turtles in the Pacific

region. This document is one of six recovery plans (one for each of the five species plus one for

the regionally important population of the East Pacific green turtle). 

While similar in format to previously drafted sea turtle recovery plans for the Atlantic,

Caribbean, and Hawaii, the unique nature of the wider Pacific region required some modification

of the recovery plan format. The geographic scope of the present plan is much larger than any

previously attempted and considers areas from the western coastal United States extending to

Guam. Furthermore, the amount of jurisdictional overlap between nations, commonwealths,

territories and compact-of-free-association-states and their various turtle populations required a

broader management perspective than has been attempted previously. Finally, sea turtles have

not been studied as comprehensively in the Pacific as in other U.S. areas, and thus there are

many areas in the Pacific where basic biological and ecological information must be obtained for

management purposes. Thus, these plans have more extensive text on the general biology of the

turtles, so that they might act as a resource to managers seeking a handy reference to the

species. The plans are also subdivided into U.S. jurisdictional areas (i.e., the various territories

and the commonwealth), so that local managers can address issues within their respective regions

more easily. 

Because of the previously noted aspects of marine turtle distribution in the Pacific (e.g., wide

geographic range, multiple jurisdictions), the Recovery Team relied on the input and involvement

of a large number of advisers, as can be noted by the lengthy Acknowledgments section. It is

hoped that the resulting document is one that acts as a pragmatic guide to recovering the

threatened and endangered sea turtle populations in the Pacific Ocean.

The members of the Pacific Sea Turtle Recovery Team and the authors of this document are:

Scott A. Eckert, Ph.D. (Team Leader)

Hubbs-Sea World Research Institute

Javier Alvarado, Ph.D.

Universidad de Michoacan, Mexico

George Balazs

National Marine Fisheries Service

Richard Byles, Ph.D.

U.S. Fish and Wildlife Service

Peter Craig, Ph.D.

Office of Wildlife and Marine Resources,

Government of American Samoa

Peter Dutton, Ph.D.

Texas A&M University

Karen Eckert, Ph.D.

Wider Caribbean Sea Turtle Conservation

Network (WIDECAST)

John Engbring

 U.S. Fish and Wildlife Service

James Maragos, Ph.D.

East-West Center

Robert Pitman

National Marine Fisheries Service

Susan Pultz

U.S. Fish and Wildlife Service

James I. Richardson. Ph.D.

University of Georgia
iv

ACKNOWLEDGMENTS

The team wishes to thank and acknowledge the following technical advisors and contributors to

these recovery plans:

David Aldan, Department of Natural Resources, Saipan, MP 

Pablo Arenas, Inter-American Tropical Tuna Commission

Representative Mariano W. Carlos, Palau 

Chuck Cook, The Nature Conservancy

Donald David, FSM

Gerry Davis, Division of Aquatic and Wildlife Resources, Dept. Agriculture, Guam

Oscar DeBrum, former Chief Secretary, RMI

Adrienne Farago, SPREP/RMTCP, Western Samoa

Michael Guilbeaux, Georgia Sea Turtle Cooperative

Vincent Hachiglou, Marine Resources Management Division, Yap State Government

Heidi Hirsh, Andersen Air Force Base, Guam

Paul Holthus, IUCN Biodiversity Program

Luciana Honigman, The Nature Conservancy

Noah Idechong, Division of Marine Resources, Palau

John Iou, Marine Resources Management Division, Yap State Government

Bruce Jensen, Pacific Magazine

Harry Kami, Hilo, Hawaii

Angela Kay Kepler, Athens, Georgia

Steve Kolinski, Marine Resources Management Division, Yap State Government

Colin Limpus, Queensland National Parks and Wildlife Service, Australia

Becky Madraisau, Micronesian Mariculture Demonstration Center, Republic of Palau

B. Renè Màrquez-M., P.N.I.T.M./INP, Mexico 

Donna McDonald, Ocean Planet Research

Ken McDermond, U.S. Fish and Wildlife Service, Honolulu

Jeffery Miller, Queensland Department of Environment & Heritage, Australia

Susan Miller, South Pacific Regional Environment Program (SPREP)

Karen Miller McClune, Hubbs-Sea World Research Institute

Moses Nelson, Marine Resources Division, FSM

Peter Oliver, RMI

Arnold Palacios, Division of Fish and Wildlife, Dept. of Natural Resources, CNMI

Peter Pritchard, Florida Audubon Society

Georgita Ruiz, Colonia Irrigacion, Mexico

Laura Sarti, Universidad Naçional Autonoma de Mexico, Mexico

Fumihiko Sato, Ogasawara Marine Center, Japan

Katsufumi Sato, Kyoto University, Japan

Asterio Takesy, Secretary of Resources and Development, FSM

Natasha Tuato’o-Bartley, Department of Marine and Wildlife Resources, American Samoa

Itaru Uchida, Port of Nagoya Public Aquarium, Japan 

Richard Wass, U.S. Fish and Wildlife Service

Phil Williams, National Marine Fisheries Service
v

LIST OF ABBREVIATIONS

CCL curved carapace length

CITES Convention on International Trade in Endangered Species of Wild Fauna

and Flora

CNMI Commonwealth of the Northern Mariana Islands

COE U.S. Army Corps of Engineers

DAWR Division of Aquatic and Wildlife Resources

EEZ Exclusive Economic Zone

ENSO El Niño - Southern Oscillation

EPA U.S. Environmental Protection Agency 

ESA Endangered Species Act

ETP Eastern Tropical Pacific

FENA females estimated to nest annually 

FSM Federated States of Micronesia

FWS U.S. Fish and Wildlife Service

HSWRI Hubbs-Sea World Research Institute

IATTC Inter-American Tropical Tuna Commission

INP Instituto Nacional de Pesca

IUCN International Union for the Conservation of Nature

MHI Main Hawaiian Islands

MIMRA Marshall Islands Marine Resource Authority

MMDC Micronesian Mariculture Demonstration Center

MRMD Marine Resources Management Division, Yap State government 

mtDNA mitochondrial DNA

NMFS National Marine Fisheries Service

NOAA National Oceanographic and Atmospheric Administration 

NPS National Park Service

NRCS Natural Resources Conservation Service (Soil Conservation Service) 

NWHI Northwest Hawaiian Islands

PNG Papua New Guinea

RMI Republic of the Marshall Islands

SCL straight carapace length

SDG&E San Diego Gas & Electric 

SPREP South Pacific Regional Environment Program

TAMU Texas A & M University

TED Turtle Excluder Device 

UNAM Universidad Naçional Autonoma de Mexico

USCG U.S. Coast Guard

USVI U.S. Virgin Islands

WIDECAST Wider Caribbean Sea Turtle Conservation Network
vi

EXECUTIVE SUMMARY 

Current Status: The olive ridley turtle is listed as Threatened in the Pacific, except for the

Mexican nesting population, which is classified as Endangered. This latter classification was

based on the extensive over-harvesting of olive ridleys in Mexico, which caused a severe

population decline. Since the ban on the harvest of turtles in Mexico, the primary threat to the

Mexican nesting population has been reduced and the population appears to be stabilizing. 

Downlisting to Threatened status may be feasible. The primary threats to the olive ridley

appear to be incidental take in fisheries and boat collisions while in U.S. waters (or by U.S.-

based fishing fleets), and the harvest of turtles and eggs on Mexican and Central American

nesting beaches. 

Goal: The recovery goal is to delist the species.

Recovery Criteria: To consider delisting all of the following recovery criteria must be met:

1) All regional stocks that use U.S. waters have been identified to source beaches based

on reasonable geographic parameters.

2) Foraging populations are statistically significantly increasing at several key foraging

grounds within each stock region. 

3) All females estimated to nest annually (FENA) at "source beaches" are either stable or

increasing for over 10 years. 

4) A management plan based on maintaining sustained populations for turtles is in effect.

5) International agreements are in place to protect shared stocks. 

Actions Needed: Three major actions are needed to achieve recovery (not in order of

priority):

1) Minimize incidental mortalities of turtles by commercial fishing operations.

2) Support the efforts of Mexico and the countries of Central America to census and

protect nesting olive ridleys, their eggs and nesting beaches.

3) Identify stock home ranges using DNA analysis.
1

RECOVERY PLAN FOR U.S. PACIFIC POPULATIONS OF THE 

OLIVE RIDLEY TURTLE (Lepidochelys olivacea)

Prepared by the

U.S. Pacific Sea Turtle Recovery Team 

I. INTRODUCTION

A. Geographic Scope

Defining the geographic range of a population of sea turtles in the Pacific Ocean is difficult. 

Sea turtles are highly migratory, and the life histories of all species exhibit complex movements

and migrations through geographically disparate habitats. Because the U.S. Pacific Sea Turtle

Recovery Team is required to focus on sea turtle populations that reside within U.S.

jurisdiction, we must delineate what constitutes a population where individuals reside

permanently or temporarily within U.S. jurisdiction and what actions must be taken to restore

that population. This has proven to be quite challenging because sea turtles do not recognize

arbitrary national boundaries and in most cases we have only limited data on stock ranges and

movements of the various populations. In this recovery plan we have tried to make these

judgements with the best information available, and to suggest means by which the United

States can promote population recovery. 

Geographic scope (from a U.S. jurisdictional perspective) for all six of the U.S. Pacific sea

turtle recovery plans (written for five species and one regionally important population) is

defined as follows: in the eastern Pacific, the west coast of the continental United States

(Figure 1a); in the central Pacific, the state of Hawaii and the unincorporated U.S. territories of

Howland, Baker, Wake, Jarvis, and Midway Islands, Johnston Atoll, Palmyra Atoll, and

Kingman Reef; in Oceania, Guam, the Commonwealth of the Northern Mariana Islands

(CNMI), and American Samoa (see Figure 1b). The U.S.-affiliated but independent nations of

the Republic of the Marshall Islands (RMI), Federated States of Micronesia (FSM), and the

Republic of Palau are also included. The FSM consists of the states of Yap, Pohnpei, Chuuk,

and Kosrae. While independent, all retain clearly defined administrative links to the United

States in the areas of defense, natural resource management, and some regulatory issues. 

Thus, we include them here in an advisory capacity. Finally, where eastern Pacific sea turtles

are held in common with Mexico, discussion of the status and recovery of these stocks will also

include discussion of the resource under Mexican jurisdiction. In all cases where U.S. sea

turtle stocks are held in common with other sovereign states, we suggest means by which the

United States can support efforts at management of those stocks by those states. We

recognize that other nations may have different priorities than the United States and we have

sincerely attempted to avoid establishing policy for those nations.

By virtue of the highly migratory behavior of adult turtles, and the shifting habitat

requirements of post-hatchlings and juveniles, populations of olive ridley turtles (Lepidochelys

olivacea) in the Pacific Ocean cross international boundaries. The following discussions

acknowledge the extended range of this species by incorporating relevant biological

information from within and without U.S. jurisdiction.


4

B. Historical and Cultural Background

Throughout most of its range, especially where abundant, the olive ridley has been

exploited for food and non-comestibles (e.g., bait, bone meal, fertilizer, oil, leather). Meat and

eggs have probably been consumed by indigenous peoples along the Pacific coast of Mexico

and Central America ever since the area was first inhabited by man. Although the meat is

palatable, it is not considered a delicacy and usually not widely sought after (Carr 1952). Olive

ridley eggs, however, are esteemed everywhere and, at least through 1979, millions were

harvested annually throughout the eastern Pacific (Cliffton et al. 1982).

Egg harvest can be an important contribution to local economies (Woody 1986; Lagueux

1991). Egg poaching is illegal in most of the countries where olive ridleys nest in the eastern

Pacific, but the laws are rarely enforced. At Ostional Beach, Costa Rica, managed egg

harvests have been undertaken to take advantage of the tremendous waste of eggs that

naturally occurs during olive ridley mass nesting (called arribadas or arribazones). Typically,

nesting females dig up or disturb previously deposited eggs at Ostional (Cornelius et al. 1991). 

Thus eggs laid during the first day of each arribada are collected and sold within the local

community (Arauz-Almengor et al. 1993). This practice shows unique promise of maintaining a

balance between a traditional source of income for coastal communities and the long-term

survival of a turtle population.

 A discussion of the "historical and cultural" background of sea turtles in the eastern Pacific

would not be complete without a discussion of the commercial fishing frenzy that decimated

turtle populations in this region during the 1960s and 1970s. During the mid 1960s, Mexico

established a turtle leather trade with Europe (mainly Italy) and Japan which vastly accelerated

the harvest of adult turtles: several million were landed over the next 15 years. The

combination of relentless egg poaching and harvesting unsustainably large numbers of adults

as they amassed off major nesting beaches ultimately led to the collapse of all but one of the

largest nesting populations in Mexico. The remaining colony, La Escobilla (Oaxaca State),

was showing signs of a major decline (Cliffton et al. 1982; Groombridge 1982) when efforts

were made by the Mexican government to protect the remaining vestiges of olive ridley nesting

populations in Mexico (Aridjis 1990).

Finally, it should be noted that olive ridleys nesting throughout the eastern Pacific (as well

as a mixture of juveniles) depend for food on rich zones of upwelling off South America and

have historically been exploited there. For example, although few, if any, olive ridleys nest in

Ecuador, large numbers immigrate there from Mexico and Central America to feed in offshore

waters. Starting around 1970, an important fishery for olive ridleys was established in

Ecuador, with several thousand turtles per year landed for a frozen meat market (Green and

Ortiz-Crespo 1982). In 1973, Ecuador entered the turtle leather export trade and landings

quickly elevated to over 100,000 turtles a year by the late 1970s (Green and Ortiz-Crespo

1982) before the industry was banned altogether (Hurtado 1982).

 

Olive ridley numbers are so small within U.S. territorial waters that there has probably

never been a directed harvest there (see Stinson 1984). However, olive ridleys are incidentally

captured and sometimes killed by U.S. tuna purse seine fishermen operating in the Eastern
5

Tropical Pacific (ETP) with an estimated annual mortality of less than 100 turtles (S. Eckert,

Hubbs-Sea World Research Institute, pers. comm.).

C. Taxonomy

This species was originally described as Testudo mydas minor Suckow, 1798, later

renamed Chelonia olivacea Eschscholtz, 1829, and eventually Lepidochelys olivacea Fitzinger,

1843. The genus name is derived from the Greek words lepidos, meaning scale, and chelys,

meaning turtle, possibly in reference to the supernumerary costal scute counts characteristic of

this species (cf. Smith and Smith 1979). The etymology of the English vernacular name

"ridley" is unclear (Dundee 1992). Lepidochelys is the only sea turtle genus with more than

one extant species: L. olivacea and the closely related Kemp's ridley L. kempii (Bowen et al.

1991). Although the name L. o. remivaga has been proposed for the eastern Pacific

populations, there are no currently accepted named subspecies (Pritchard 1969a; Smith and

Smith 1979). Detailed taxonomic reviews of this genus and species are provided by Smith and

Smith (1979) and Pritchard and Trebbau (1984). 

D. Description

Historically, field researchers and observers have had difficulty distinguishing olive ridleys

from loggerhead turtles (Caretta caretta), which has led to erroneous distribution and breeding

records that still persist today (Nishimura 1967; Frazier 1985). The genus Lepidochelys is

characterized by its relatively small size; unusually broad carapace; four pairs of inframarginal

scutes, each or most with a posterior inframarginal pore that opens to a musk gland (Rathke's

Gland); and a medium-sized head that is triangular in planar view. The two species (olivacea

and kempii) differ in the number of lateral carapace scutes; the Kemp's ridley has five pairs

while the olive ridley can have up to nine. In fact, olive ridleys are unique among extant turtles

in having a variable, often asymmetrical, lateral scute count, ranging from five to nine plates on

each side, but with six to eight being the most common. While both of the two recognized

species occur in the Atlantic Ocean, only L. olivacea is found in the Pacific Ocean.

The olive ridley is the smallest living sea turtle, with an adult carapace length usually

between 60 and 70 cm. Schulz (1975) measured 500 females in Suriname and reported an

average carapace length of 68.5 cm (range 63-75 cm). Pacific olive ridleys are slightly smaller. 

The modal length class of a sample of 99 nesting females from Pacific Honduras was 65-65.9

cm, with a range of 58-74 cm (Pritchard 1969a). Ridleys from Playa Nancite, Costa Rica, have

a mean carapace length of 63.3 cm (range = 54.0-72.5 cm, n = 251; Hughes and Richard

1974). Márquez et al. (1976) listed carapace lengths for mature females from nesting beaches

in different states in Pacific Mexico as follows: Oaxaca, mean = 62.9 cm (range = 52.5-73, n =

1,203); Guerrero, mean = 63.5 cm (range = 52-73.5, n = 253); Michoacan, mean = 63.1 cm

(range = 60-67, n = 13); Colima, mean = 64.3 cm (range = 60-68, n = 19); Jalisco, mean =

63.2 cm (range = 54-70, n = 115); Sinaloa, mean = 62.2 cm (range = 55-69, n = 190). 

Hatchlings from Mexico measure from 34.7 to 44.6 mm (straight carapace length [SCL])

(Márquez 1990).

 Olive ridleys rarely weigh over 50 kg (Schulz 1975). Adult females captured off Oaxaca,

Mexico, weighed an average of 35.45 kg (n = 58); males weighed significantly less with an
6

average of 33.00 kg (n =17). The entire sample ranged from 25 to 46 kg (Frazier 1983). 

Hatchlings weigh between 12.0 and 22.3 g (Márquez 1990).

Adults are olive or grayish green above, but sometimes appear reddish due to algae

growing on the carapace. The underparts are greenish white, especially in younger

specimens, becoming creamy yellow with age. Hatchlings are all black when wet (dark gray

otherwise) with a pale yolk scar. Hatchlings and juveniles have serrated posterior marginals;

these become smooth with age and the adult has a rounded carapace. Juveniles also have

three longitudinal dorsal keels; the central keel gives younger animals a serrated profile and

persists almost until maturity. Two keels on the plastron also disappear with age.

Adults are moderately sexually dimorphic. As in other cheloniids, mature males have

substantially longer and thicker tails than females (used for copulation), and one of the claws

on the front flippers is enlarged and strongly hooked (used to grasp the carapace of the female

during copulation). The male has a longer, more tapered carapace than the more rounded

female, while the female has a higher, more domed carapace (Frazier 1983). Males have a

more concave plastron, presumably adaptive for mating (Wibbels et al. 1991). For detailed

information on the description of this species see Pritchard and Trebbau (1984).

E. Population Distribution and Size

The olive ridley sea turtle is widely regarded as the most abundant sea turtle in the world

(Carr 1972; Zwinenberg 1976). Until recent historical times and the advent of modern

commercial exploitation of sea turtles, the olive ridley was superabundant in the eastern

Pacific, undoubtedly outnumbering all other sea turtle species combined in the area. For

example, Carr (1972) states that more than 1,000,000 olive ridleys were commercially

harvested in Mexico during 1968 alone, and Cliffton et al. (1982) estimated that a minimum of

10,000,000 olive ridleys swam in the seas off Pacific Mexico before the recent era of

exploitation.

Nesting Grounds

Preferred nesting areas occur along continental margins and, rarely, on oceanic islands. 

The largest nesting aggregation in the world occurs in the Indian Ocean along the northeast

coast of India (Orissa), where in 1991 over 600,000 turtles nested in a single week (Mrosovsky

1993). The second most important nesting area occurs in the eastern Pacific, along the west

coast of Mexico and Central America. Elsewhere, olive ridleys nest in much smaller numbers

including along the Atlantic coast of South America and western Africa, as well as in the

western Pacific and Indian oceans (Sternberg 1981; Groombridge 1982; Carr and Carr 1991).

In the eastern Pacific, the largest nesting concentrations occur in southern Mexico and

northern Costa Rica, with stragglers nesting as far north as southern Baja California (Fritts et

al. 1982) and as far south as Peru (Brown and Brown 1982). Hubbs (1977) reported a pair of

olive ridleys mating off the La Jolla coast in southern California, but there is no known nesting

there. Indeed, with the exception of a single nesting in September 1985 on the island of Maui,

Hawaii (Balazs and Hau 1986), there is no nesting by this species anywhere in the United

States or the territories under U.S. political jurisdiction (see Geographic Scope). 
7

 Although the olive ridley is renowned for its arribadas, most nesting areas support only

small or moderate-sized aggregations (up to 1,000 nesting females) (Groombridge 1982). 

Although the spectacular nesting emergences at beaches such as Orissa in India, Playas

Ostional and Nancite in Costa Rica, and La Escobilla in Mexico, have received a good deal of

attention from biologists and conservationists, the overall contribution of smaller nesting

beaches may be of considerable importance.

According to A. Abreu G. (pers. comm.), the number of females nesting in Mexico annually

are: Baja California Norte - 3; Baja California Sur - 71; Sonora - status unknown; Sinaloa - 612;

Nayarit - 100; Jalisco - 830; Colima - present; Michoacan - 500; Guerrero - 1,415; Oaxaca -

157,500; Chiapas - 430; total - 161,501. Márquez (1990) estimated over 200,000 nests per

year at La Escobilla, Morro Ayuta, Chacahua, Piedra de Tlacoyunque, and Mismaloya-La

Gloria nesting beaches. Sternberg (1981) erroneously lists Islas Revillagigedos (Mexico) as a

nesting area.

Márquez (1990) cited an estimate of 3,000 nests per year in Guatemala, and Higginson

(1989) stated that 21,067 olive ridleys nested there annually during 1981 and 1982. [Data on

population size in the eastern Pacific are variously reported either as number of nests or

number of nesting females. These data can be loosely compared by remembering that most

females deposit two clutches of eggs per year (Plotkin et al. 1994).] Olive ridleys nest at least

in small numbers in El Salvador, but no specific information is available (Cornelius 1982). 

According to C. Lagueux (Univ. Florida, pers. comm.), olive ridleys nest on many islands in

the Gulf of Fonseca (Honduras) and on the mainland from the border with Nicaragua to Punta

Novillo, located on the west side of Isla Zacate Grande; over half of the nesting occurring at

three mainland sites: Punta Raton, Cedeño, and El Carretal. Cornelius (1982) cited an

estimate of 3,000 nesting females for all of Pacific Honduras and reported that the population

was declining. In 1987, olive ridleys laid an estimated 2,000 clutches (= ca. 1,000 nesting

females) (C. Lagueux pers. comm.).

There are two primary arribada beaches in Nicaragua, Playa Chacocente (or Chococente)

and Playa La Flor, both located in the southern Department of Rivas. Arribada activity peaks

in August- October. Cornelius (1982) stated that olive ridley populations had declined from

former times but that the ridleys were still the most abundantly nesting sea turtle on the Pacific

coast. Calculating from egg exports in 1975-1976, Cornelius (1982) estimated minimum

numbers of nesting females at 2,800 and 3,200, respectively. In actual fact the population(s)

are larger. Typically, 5,000-10,000 females participate in peak season arribadas. Higher

numbers have been recorded; for example, 12,960 females nested from 13-18 October in

Playa La Flor’s largest 1994 arribada (MARENA, in litt. K. Eckert 14 July 1995). Egg collection

quotas allow more than half million eggs (from the two beaches combined) to be harvested

each year.

Costa Rica supports the largest nesting aggregations of Lepidochelys olivacea in the

eastern Pacific and, with the exception of Orissa, India, the largest nesting aggregations for

this species in the world. Two beaches are most important: Playa Nancite and Playa Ostional. 

Playa Nancite is 1.0 km in length and typically receives 25,000-50,000 turtles per year. Playa

Ostional is three km in length and typically receives 450,000-600,000 turtles per year. At both
8

sites arribadas peak in the months of September and October. As many as 30,000 females

may nest in one arribada at Nancite, and as many as 100,000 females at Ostional. Both

populations appear to have reached their carrying capacities, as shown by significant numbers

of nests predictably exhumed by later nesting females. Average annual hatch success ranges

from 3.0 to 22%. Census data initiated in 1980 and continuing to the present, indicates that

population at Playa Nancite is declining. There are no long term data for Playa Ostional

(Claudette Mo, Univ. Nacional de Costa Rica, pers. comm., 1995).

Isla Cañas has by far the largest population in Panama with an estimated 20,000 nesting

females; approximately 10,000 females nest throughout the remainder of the country (R.

Chang, Dirreción Nacional des Áreas Protegidas y Vida Silvestre, pers. comm.). Cornelius

(1982) stated that the number of ridleys nesting in Panama appeared to be drastically reduced

from former levels.

The olive ridley is the most commonly nesting sea turtle in Pacific Colombia (Amorocho et

al. 1989), but no estimate of the size of the breeding population there is available. Although

olive ridleys are not known to nest in Ecuador (Green and Ortiz-Crespo 1982), breeding occurs

in countries to the north and south and it seems likely that at least a few must nest there. 

Brown and Brown (1982) reported a single nest from northern Peru and cited additional

evidence that small numbers of olive ridleys may regularly nest in that country. 

Insular and Pelagic Range

The olive ridley occurs worldwide in tropical and warm temperate ocean waters. It is by far

the most common and widespread sea turtle in the waters of the eastern Pacific (Pitman 1990;

Inter-American Tropical Tuna Commission [IATTC], unpubl. data); it is increasingly uncommon

further offshore, and rare in the central Pacific, both at sea and around islands (Balazs 1982a). 

At sea occurrences in the United States and waters under U.S. jurisdiction are limited to the

west coast of the continental United States (Stinson 1984) and Hawaii where the species is

rare (Balazs 1982a), but sightings are reportedly increasing (Balazs 1983). A 57 cm (SCL)

individual was hooked by a fisherman in Los Angeles Harbor and brought to Sea World of San

Diego in 1983 (M. Shaw, Sea World, pers. comm.). There are no reported encounters with

olive ridley turtles in U.S. Pacific territorial waters (see Geographic Scope). 

Concentrations at sea have been noted mainly in tropical neritic waters, usually adjacent to

known nesting areas. Unpublished data assembled by the IATTC show that olive ridleys are

present from 30EN to 15ES and are most often seen within 1,200 nautical miles from shore

(although they are seen as far as 140EW, and it is not uncommon to find large groups

hundreds of miles from the nearest coast). Arenas and Hall (1992) report aggregations of over

100 animals as far offshore as 120EW. Although there is strong evidence for moderate

seasonal movements of olive ridleys within the eastern Pacific (see Movements and Migration),

regular transoceanic migrations are unknown.

Observations by the IATTC indicate seasonal distribution for the olive ridley. Values for the

relative frequency of occurrence index were usually high near the coasts of central and south

America, especially during July through December (the nesting season peak), and the index

was always low off Mexico (despite seasonal high density nesting in Oaxaca). There was also

seasonal distribution by sex and size; southeast of the Galapagos Islands, and in the area
9

between the Revillagigedo Islands and Baja California, only females were observed. Over

two-thirds of all small individuals were seen in the feeding area off Ecuador and Colombia

during July through December. In the offshore region, both males and females were observed

but only during May through June (IATTC, unpubl. data).

Data collected during tuna fishing cruises from Baja California to Ecuador and from the

coast to almost 150EW indicated that the two most important areas in the Pacific for the olive

ridley are the central American coast and the nursery/feeding area off Colombia and Ecuador,

where both adults (mostly females) and juveniles are often seen (IATTC, unpubl. data). Large

groups (again, mostly females) were also observed in the Humboldt Current area southeast of

the Galapagos Islands. The largest group (at least 216 turtles) observed by Arenas was near

the Gulf of Guayaqui, Ecuador.

F. Status

The olive ridley is classified as Endangered according to the World Conservation Union

(IUCN) Red Data Book (Groombridge 1982), and is listed in Appendix I of the Convention on

International Trade in Endangered Species of Wild Fauna and Flora (CITES). According to the

Code of Federal Regulations (50 CFR 17.11), under the U.S. Endangered Species Act of 1973

(ESA), as amended, nesting populations of olive ridleys along the Pacific coast of Mexico are

listed as Endangered and all others are listed as Threatened. However, the National Marine

Fisheries Service (NMFS) intends to propose upgrading the Atlantic population(s) of olive ridley

to Endangered (P. Williams, NMFS, pers. comm.).

G. Biological Characteristics

Migration and Movements

Hatchlings leave the beach to begin what is presumed to be a pelagic phase, the so-called

"lost year". No information is available on the movements or the kind of habitat these turtles

use during their first year (or possibly years) of life. Information on the habitat of juvenile

ridleys is almost nonexistent. During a three hour period on 14 September 1989, R. Pitman

observed 75 turtles (only olive ridleys identified), 90 to 120 nautical miles due southwest of

Acapulco, Mexico. Numerous individuals in the 20-30 cm size range were present. These

turtles were noticeably more common in areas where flotsam and debris were also visible at

the surface (R. Pitman, NMFS, unpubl. data). During tuna fishing cruises in the eastern

Pacific, the only place turtles less than 60 cm were seen was in the feeding/nursery area in the

Panama Bight, off Ecuador and Colombia (IATTC, unpubl. data). It is possible that young

turtles move offshore and occupy areas of surface current convergences to find food and

shelter among aggregated floating objects until they are large enough to recruit to the

nearshore benthic feeding grounds of the adults. A similar scenario has been suggested for

hatchling loggerheads that associate with Sargassum weed in the western Atlantic (Carr 1987).

Information on the movements of adult olive ridleys comes from recaptures of females

previously tagged on nesting beaches and satellite telemetry studies. Cornelius and Robinson

(1986) reported on 189 recaptured individuals from over 45,000 ridleys tagged in Costa Rica,

and summarized results of smaller scale tagging efforts in Mexico and Nicaragua. Turtles
10

nesting in Costa Rica were recovered as far south as Peru, as far north as Oaxaca, Mexico,

and offshore to a distance of 2,000 km. The majority (37.6%) were recaptured in Costa Rican

waters, 28.6% were recaptured in countries south of Costa Rica and 32.3% were recaptured

north of Costa Rica. Cornelius and Robinson (op. cit.) reviewed data on surface current flow in

the eastern Pacific but were not able to draw any conclusions about whether the movements

of Costa Rican ridleys were the result of active migrations or passive drifting with these

currents.

Regardless of the mode of transport, there is evidence to suggest that many ridleys

undergo a regular migration within the eastern Pacific between breeding grounds in the north

and feeding grounds to the south. Of the 54 ridleys recaptured south of Costa Rica in the

Cornelius and Robinson (1986) study, 80% were from Ecuador, and turtles tagged in Mexico

and Nicaragua have also been recaptured in Ecuador. From 1970-1979, turtle fishermen were

taking up to 90,000 ridleys per year (Green and Ortiz-Crespo 1982) in Ecuador, a country

where apparently very few ridleys actually nest (none according to Green and Ortiz-Crespo

1982). These and other data (e.g., Hurtado 1981; Meylan 1982) suggest that the huge

numbers of ridleys that occur (or formerly occurred) off Ecuador and Colombia are comprised

of seasonal migrants from nesting populations to the north.

Plotkin et al. (1994) provide further insight into olive ridley movements. Satellite monitoring

of post-nesting movements (from Nancite Beach, Costa Rica) showed migration routes

traversing thousands of kilometers over deep (>1,000 m) oceanic water, distributed over a very

broad range from Mexico to Peru and over 3000 km west of Costa Rica. Their data further

indicated that rather than migrating to one specific foraging area after nesting, olive ridleys are

nomadic and exploit multiple feeding areas. Sightings of large aggregations of ridleys at sea

(e.g., Oliver 1946) have led to unconfirmed speculation that turtles travel in large flotillas

between nesting beaches and feeding areas (Márquez 1990).

Foraging Biology and Diet

Data on the food and foraging habits of olive ridleys are remarkably sparse with much of

the information only anecdotal. An early suggestion that olive ridleys are primarily vegetarian

(Deraniyagala 1939; Bustard 1972) has not been substantiated (Márquez et al. 1976). The

general picture suggests a catholic diet with crustaceans playing a major role. Identified prey

include a variety of mostly benthic, but also some pelagic, prey items. Benthic prey include

bottom fish, crabs, oysters, sea urchins, snails, sessile tunicates, shrimp, and algae; pelagic

prey include jellyfish medusae, salps, and pelagic red crabs (Pleuroncodes planipes)

(Deraniyagala 1939; Carr 1961; Caldwell 1969; Fritts 1981; Cornelius and Robinson 1986;

Mortimer 1982; Márquez 1990). Landis (1965) reported a sighting by the crew of a semisubmersible craft from Scripps Institution of Oceanography (University of California) of a

"green turtle" feeding on crabs at a depth of 300 m in the Sea of Cortez. This turtle

identification was later corrected as an olive ridley (Eckert et al. 1986). Olive ridleys have also

been observed feeding on flotsam-associated epibiota, mostly acorn and gooseneck

barnacles, molluscs, algae and crabs (IATTC, unpubl. data).

The most complete study of olive ridley diet in the eastern Pacific (Montenegro et al. 1986,

cited in Márquez 1990) indicates the wide variety of prey taken by this species: adult males (n

= 24) fed mainly on fishes (57%), salps (38%), crustaceans (2%), and molluscs (2%), while
11

adult females (n = 115) fed on salps (58%), fishes (13%), molluscs (11%), algae (6%),

crustaceans (6%), bryozoans (0.6%), sea squirts (0.1%), sipunculid worms (0.05%), and fish

eggs (0.04%). Olive ridleys off western Baja California may feed almost entirely on pelagic red

crabs (Márquez 1990), which are superabundant in that area (Pitman 1990).

There are several accounts of olive ridleys being caught on longline fishing gear (e.g.,

Pritchard 1977; Fritts 1981; Balazs 1982b; Cornelius and Robinson 1986). Bait used in these

cases include fish (Fritts 1981), squid (R. Pitman, NMFS, pers. obs.), shrimp and turtle meat

(Cornelius and Robinson 1986). These observations suggest that olive ridleys scavenge at

times, which should be considered when evaluating food and feeding habits based on

stomach contents alone. The only information on the natural diet of olive ridleys in offshore

waters comes from Bailey and Bailey (1974) who butchered a specimen they collected several

hundred miles west of Costa Rica. The turtle was full of shell fragments and they assumed it

had been feeding on crabs that had taken up residence around their life raft. Olive ridleys in

the open ocean of the eastern Pacific are often seen near floating objects, possibly to feed on

associated fish and invertebrates (Pitman 1992; IATTC unpubl. data). 

Growth

Nothing is known about the growth rates of wild olive ridleys. Three hatchlings sent to Sea

World of California in December of 1988 and measured on 23 March 1989 averaged 90.3 mm

SCL and 169.3 gm. After nearly 15 months, they had gained an average of 265.7 mm and

7,230.7 gm. After just over 18 months, two of the turtles had gained an average of 288.5 mm

and 8,723.0 gm since their initial measurement (McDonald and Dutton, unpubl. data).

Reproduction

Most mating is generally assumed to occur in the vicinity of nesting beaches (Márquez et

al. 1976), but copulating pairs have also been reported over 1,000 km from the nearest nesting

beach (Hubbs 1977; Pitman 1990). From research conducted at Playa Nancite, Costa Rica, it

appears that the number of copulating (or courting) pairs observed near the nesting beach

cannot account for the fertilization of tens of thousands of gravid females, and some if not the

majority of mating must occur away from the nesting grounds (O. Owens, Texas A & M

University [TAMU], pers. comm.). Arenas and Hall (1992) observed that turtles start to

aggregate near the nesting beach two months before the nesting season. 

Olive ridleys nest throughout the year in the eastern Pacific with peak months, including

major arribadas, occurring from September through December. Preferred nesting habitat is a

relatively flat, middle beach zone, free of debris (Cornelius 1976). Beach fidelity is not

absolute. Hughes and Richard (1974) reported individual ridleys nesting at both Playa Naranjo

and Playa Nancite, Costa Rica, approximately 1.5 km apart, during the same season. Nesting

is mostly nocturnal but some diurnal emergences are known, especially during large arribadas

(Pritchard 1969a; Caldwell and Casebeer 1964; Cliffton et al. 1982). Age at sexual maturity is

not known, but there are data on the minimum breeding size. For example, the average length

of 251 turtles nesting at Playa Nancite, Costa Rica, was 63.3 cm, with the smallest being 54.0

cm (Hughes and Richard 1974). 
12

Ten of 22 nesting females recaptured at Punta Raton, Honduras, had internesting intervals

of 15 to 17 days (Minarik 1985). Similarly, Pritchard (1969b) and Schulz (1975) reported

modal internesting intervals of 17 days and 16 days, respectively, for olive ridleys nesting in

Suriname. These are typical internesting intervals for solitary nesters. Most olive ridleys,

however, undertake to nest synchronously in arribadas which typically occur on 28-day, lunarassociated cycles. For example, Márquez et al. (1982) report that olive ridleys nesting in

Mexico show "clear internesting cycles every 28 days." 

Gravid females ascend the beach with an alternate gait, excavate a nest chamber with

their rear flippers, deposit the clutch, and vigorously tamp down the nest site with their plastron

after the eggs are covered. Most females lay two clutches of eggs per season, remaining

nearshore for the approximately one month internesting period (Plotkin et al. 1994). Mean

clutch size for Mexican populations is 105.3 eggs (n = 1,120 nests) (Márquez 1990). Mean

clutch sizes for two nesting beaches in Costa Rica is 99.6 eggs (SD = 17.0, n = 115 nests) and

107.4 eggs (SD = 17.4, n = 66) (Cornelius et al. 1991). Eggs range from 32.1 to 44.7 mm in

diameter and 30 to 38 g. Incubation usually takes from 50 to 60 days, but can vary depending

on temperature, humidity, sand grain size and organic content. Hughes and Richard (1974)

found that individuals from nests in shady, vegetated areas took up to 70 days or more to

hatch.

Plotkin et al. (in review) satellite-tagged nesting females during an arribada at Playa

Nancite, Costa Rica, and monitored internesting movements and cohort cohesiveness. They

found that the turtles dispersed away from each other during the internesting period, returning

to nest in successive arribadas. After their final nest, the turtles from each of the three cohorts

studied dispersed independently of each other.

It is noteworthy that scientific opinions differ as to the extent to which arribadas, which are

unique to Lepidochelys, contribute to overall population status. Some researchers feel that the

tremendous reproductive output of arribadas is essential to the success of the species by

subsidizing smaller colonies elsewhere. For example, Lagueaux 1991 mentions beaches in

Nicaragua where 100% of the eggs have been harvested for many years. It seems logical that

those beaches recruit breeding turtles from other populations. On the other hand, the

excessive egg loss (up to 99.8% in some instances) and the subsequent decline in

reproductive output suggests that traditional arribada beaches may fall far short of their

reproductive potential and may not be primarily responsible for maintaining olive ridley

populations in the ETP. 

The greatest single cause of olive ridley egg loss comes from the nesting activity of

conspecifics on arribada beaches where nesting turtles destroy eggs by inadvertently digging

up previously laid nests or causing them to become contaminated by bacteria and other

pathogens from rotting nests nearby. At Playa Nancite, Costa Rica, an estimated 0.2% of 11.5

million eggs laid during a single arribada produced hatchlings (Hughes and Richard 1974). 

Predators also contribute to egg loss and include coyotes, opossums, raccoons, coatimundies,

feral dogs and pigs, and humans. At Playa Nancite during 1981-1984 an average of 14.2%

nests per year was excavated by mammalian predators (range 3.4-25%), with coatimundies

being the most numerous predator (Cornelius et al. 1991). Abiotic sources of egg loss include

inundation by high tides and erosion. 
13

The predators of hatchlings are legion: on the beach they include crabs, snakes, iguanas,

frigatebirds, vultures, coyotes, and racoons; in the water they include predatory fish (Hughes

and Richard 1974).

Offshore Behavior

In the eastern tropical Pacific the olive ridley occurs much more commonly in the open

ocean than any other cheloniid (Pitman 1990), but this may only be a function of its being

much more abundant than any of the other species and thus increasing the likelihood of their

being wayward individuals. Alternatively, olive ridleys may have a truly pelagic habit. Further

research is needed in this regard.

At sea in the eastern tropical Pacific, olive ridleys readily associate with objects floating in

the water including anything from logs to plastic debris to dead whales (Pitman 1992; Arenas

and Hall 1992), and appear strongly attracted to brightly colored objects (Arenas and Hall

1992). The reason for this association is unknown but shelter from predators seems likely,

although turtles may also be feeding on fishes and other organisms that aggregate around

floating objects. Observations by the IATTC (unpubl. data) indicated that only 17% of all

positively identified olive ridleys were seen in open water, 44% were observed near floating

objects.

Olive ridleys often bask at the surface in the eastern Pacific where they are frequently

accompanied by seabirds (Oliver 1946; Márquez 1990; IATTC, unpubl. data). The birds,

mainly boobies, roost on the exposed carapaces of the turtles and feed on fish that aggregate

beneath them (Pitman 1993).

Health Status

Almost nothing is known about disease or natural mortality rates in olive ridley populations. 

Cornelius and Robinson (1983) reported that some nesting females in Costa Rica in 1982 had

fleshy tumors on the head, neck and front flippers that had not been noticed during the 1970s. 

A. Chavez (pers. comm.) confirmed cases of fibropapillomas (tumor disease) on ridleys nesting

in Costa Rica, but the occurrences were relatively rare and infestations usually minor.

As with all marine turtles, sharks are likely to be major predators of all age classes at sea

(Hughes and Richard 1974; Stancyk 1982). Nesting females with missing flippers and

damaged shells, presumably due to shark attacks, are common in both the Atlantic (Pritchard

1969b) and the eastern Pacific (Cornelius and Robinson 1983). G. Friedrichsen (pers. comm.)

photographed a juvenile olive ridley (estimated carapace length: 30 cm) that had been

swallowed whole by a pelagic white-tipped shark (Carcharinus longimanus) caught in the

eastern Pacific.

During research cruises in the eastern Pacific in the fall of 1989 and 1990, 11 dead olive

ridleys were found floating far offshore in widely scattered areas (R. Pitman, pers. obs.). One

had been killed after being impaled by a sailfish (Istiophorus platypterus) (Frazier et al. 1994)

and another had apparently been killed by fishermen after it got caught on a longline hook. 

The remaining turtles died of unknown but possibly natural causes because nearly all were

emaciated and apparently starved to death with no outward signs of trauma. Cornelius (1975)
14

reported on a late-year die-off of marine turtles (mostly greens [Chelonia mydas], but also olive

ridleys) off Costa Rica and speculated that a toxin such as ciguatera or red tide may have

been responsible. It is possible that similarly affected turtles could drift for weeks, possibly

months, and be carried far offshore before succumbing.

In addition to the cases cited above, two moribund olive ridleys were captured far offshore

that had cataracts in both eyes and may have been starving due to blindness (R. Pitman, pers.

obs.), although blindness does not necessarily imply death for this species (Mora and

Robinson 1982).

H. Threats

This section presents a brief overview of threats to olive ridley turtles in the Pacific basin,

followed by summaries of major threats in each U.S.-affiliated area. A third section then

presents more detailed information specific to each area where this species occurs.

"Threats" to sea turtles are broadly defined as any factor that jeopardizes the survival of

turtles or impedes the recovery of their populations. Twenty-six threats have been identified,

but it is readily apparent that all are not equally important and that threats in one Pacific area

may not be relevant in another area. Consequently, each area was evaluated separately

based on information received from the Recovery Team and Technical Advisors. Table 1 lists

the 15 threats in the marine environment and ranks their significance. Definitions of the

threats are provided in subsequent text.

Pacific Synopsis

Lack of knowledge concerning the abundance and distribution of olive ridley turtles in the

northeastern Pacific constitutes a threat, particularly since important foraging grounds have not

been identified. Forage areas most likely exist along the coast of Baja California and southern

California, however, these vital areas cannot be given adequate protection until they have

been identified. The breeding population origins and migratory habits of the olive ridley turtles

frequenting waters off the west coast of the United States are unknown. Threats to migrating

turtles are therefore also unknown. This information is important to determining their status

and necessary for effective management.

Regional Summaries

U.S. West Coast

Primary turtle threats: incidental take in fisheries

boat collisions

Olive ridleys have occasionally been killed by gillnets and boat impacts as well as coldstunning in Oregon and Washington.
15

Hawaii

Primary turtle threats: incidental take in fisheries

While rare in Hawaii, olive ridleys have occasionally been killed by commercial fishing

vessels. The entanglement of juveniles and adults in marine debris around the Hawaiian

islands is reported from Kailua-Kona (Hawaii). Pukoo (Molokai), Hana (Maui), and Oahu

(Balazs 1985).

American Samoa

Primary turtle threats: none

Guam

Primary turtle threats: none

Republic of Palau

Primary turtle threats: none

Commonwealth of the Northern Mariana Islands (CNMI)

Primary turtle threats: none

Republic of the Marshall Islands (RMI)

Primary turtle threats: none

Federated States of Micronesia (FSM)

Primary turtle threats: none
a

 There is no known nesting by this species in the United States or in any territory under U.S.

jurisdiction. Therefore, only threats in the marine environment (#12-26) are included in this table.

16

TABLE 1. Threat checklist for Codes 1 = major problem - = not current problem

olive ridley sea turtles in the 2 = moderate problem ? = unknown

Eastern and central Pacific Ocean.a3 = minor problem P = known problem but 

 extent unknown

 

Threat U.S.

West

Coast

Hawaii Amer.

Samoa 

Guam Palau CNMI RMI FSM Uninc.

Marine Environment

12 Directed take - - - - - - - - -

13 Natural disasters 3 - - - - - - - -

14 Disease/parasites - - - - - - - - -

15 Algae/Seagrass/reef

degradation

- - - - - - - - -

16 Environmental Contaminants - - - - - - - - -

17 Debris (entangle/ingest) 3 3 - - - - - - -

18 Fisheries (incidental take)

-domestic waters 3 2 - - - - - - -

-international 2 2 - - - - - - -

19 Predation - - - - - - - - -

20 Boat collisions 2 - - - - - - - -

21 Marina/dock development - - - - - - - - -

22 Dredging - - - - - - - - -

23 Dynamite “fishing” - - - - - - - - -

24 Oil exploration/development - - - - - - - - -

25 Power plant entrapment - - - - - - - - -

26 Construction blasting - - - - - - - - -
17

General Threat Information

This section provides the supportive information used to rank the turtle threats listed in

Table 1. Each threat is defined and then evaluated separately for each of the eight

U.S.-affiliated island groups. The first 11 threats pertain to the turtle's nesting environment,

the latter 15 to the marine environment.

Nesting Environment

While no olive ridleys nest in U.S. jurisdiction, it is important that the United States

participate in restoration efforts of U.S. sea turtle stocks at their nesting beaches. Thus, we

have chosen to add a general description of nesting beach threats, so that U.S. resource

managers can make informed decisions on policies to support turtles in other political

jurisdictions. 

1. Directed Take

The harvest of sea turtles and/or their eggs for food or any other domestic or commercial

use constitutes a widespread threat to these species. Removing breeding adults from a

population can accelerate the extinction of local stocks, and the persistent collection of eggs

guarantees that future population recruitment will be reduced. This category includes only the

harvest of sea turtles (typically nesting females) and their eggs on land. Harvest at sea is

discussed in a later section. (see Recovery - Section 1.1.1.1)

2. Increased Human Presence

Human populations are growing rapidly in many areas of the insular Pacific and this

expansion is exerting increasing pressure on limited island resources. Threats to sea turtles

include increased recreational and commercial use of nesting beaches, the loss of nesting

habitat to human activities (e.g., pig pens on beaches), beach camping and fires, an increase

in litter and other refuse, and the general harassment of turtles. Related threats, such as

coastal construction, associated with increasing human populations are discussed separately. 

(see Recovery - Sections 1.1, 1.2)

3. Coastal Construction

The most valuable land on most Pacific islands is often located along the coastline,

particularly when it is associated with a sandy beach. Construction is occurring at a rapid rate

and is resulting in a loss of sea turtle nesting areas. This section discusses

construction-related threats to the region's sea turtle nesting beaches, including the

construction of buildings (hotels, houses, restaurants), recreational facilities (tennis courts,

swimming pools), or roads on the beach; the construction of sea walls, jetties, or other

armoring activities that can result in the erosion of adjacent sandy beaches; clearing stabilizing

beach vegetation (which accelerates erosion); and the use of heavy construction equipment on

the beach, which can cause sand compaction or beach erosion. (see Recovery - Sections

1.1.2, 1.2)
18

4. Nest Predation

The loss of eggs to non-human predators is a severe problem in some areas. These

predators include domestic animals, such as cats, dogs and pigs, as well as wild species such

as rats, mongoose, birds, monitor lizards, snakes, and crabs, ants and other invertebrates. 

(see Recovery - Section 1.1.3)

5. Beach Erosion

Weather events, such as storms, and seasonal changes in current patterns can reduce or

eliminate sandy beaches, degrade turtle nesting habitat, and cause barriers to adult and

hatchling turtle movements on affected beaches. (see Recovery - Section 1.1.5.2, 1.2.1)

6. Artificial Lighting

Hatchling sea turtles orient to the sea using a sophisticated suite of cues primarily

associated with ambient light levels. Hatchlings become disoriented and misdirected in the

presence of artificial lights behind (landward of) their hatching site. These lights cause the

hatchlings to orient inland, whereupon they fall prey to predators, are crushed by passing cars,

or die of exhaustion or exposure in the morning sun. Nesting adults are also sensitive to light

and can become disoriented after nesting, heading inland and then dying in the heat of the

next morning, far from the sea. Security and street lights, restaurant, hotel and other

commercial lights, recreational lights (e.g., sports arenas), and village lights, especially mercury

vapor, misdirect hatchlings by the thousands throughout the Pacific every year. (see Recovery

- Section 1.1.2, 1.1.4)

7. Beach Mining

Sand and coral rubble are removed from beaches for construction or landscaping

purposes. The extraction of sand from beaches destabilizes the coastline (e.g., reduces

protection from storms), removes beach vegetation through extraction or flooding and, in

severe cases, eliminates the beach completely. When mining occurs on or behind a nesting

beach, the result can be the degradation or complete loss of the rookery. In addition, females

can become confused when they emerge from the sea only to find themselves heading down

slope into a depression formed by mining activities; too often the outcome is that the female

returns to the sea without laying her eggs. Even when eggs are successfully deposited,

reduced hatch success results if nests are flooded or excavated during mining. (see Recovery

- Section 1.2.2)

8. Vehicular Driving on Beaches

Driving on the beach causes sand compaction and rutting, and can accelerate erosion. 

Driving on beaches used by turtles for egg-laying can crush incubating eggs, crush hatchlings

in the nest, and trap hatchlings after they emerge from the nest cavity and begin their trek to

the sea. In the latter case, hatchlings are exposed to exhaustion and predators when they fall

into and cannot climb out of tire ruts that are typically oriented parallel to the sea. (see

Recovery - Section 1.2.6)
19

9. Exotic Vegetation

Introduced species can displace native dune and beach vegetation through shading and/or

chemical inhibition. Dense new vegetation shades nests, potentially altering natural hatchling

sex ratios. Thick root masses can also entangle eggs and hatchlings. (see Recovery - Section

1.2.3)

10. Beach Cleaning

Removal of accumulated seaweeds and other debris from a nesting beach should be

accomplished by hand-raking only. The use of heavy equipment can crush turtle eggs and

hatchlings and can remove sand vital to incubating eggs. (see Recovery - Sections 1.2.5)

11. Beach Replenishment

The nourishment or replacement of beaches diminished by seawalls, storms, or coastal

development can reduce sea turtle hatching success by deeply burying incubating eggs,

depositing substrate (generally from offshore deposits) that is not conducive to the incubation

of sea turtle eggs, and/or obstructing females coming ashore to nest by machinery, pipelines,

etc. (see Recovery - Section 1.2.4)

Marine Environment

12. Directed Take 

The harvest of juvenile and adult sea turtles for food or any other domestic or commercial

use constitutes a widespread threat to these species. In particular, the exploitation of large

juveniles and adults can accelerate the extinction of both local and regional stocks. This

category includes only the harvest of sea turtles at sea. Harvest on the nesting beach was

discussed in a previous section. (see Recovery - Section 2.1) 

 

There is no directed take of olive ridleys in U.S. waters.

13. Natural Disasters

Natural phenomena, such as cyclones, can contribute to the mortality of turtles at sea,

particularly in shallow waters. Disease epidemics and other debilitating conditions that affect

prey items (sea grass, coral, sponges, reef invertebrates) can also harm sea turtle populations. 

Storms can alter current patterns and blow migrating turtles off course into cold water. 

Unseasonal warm water incursions from subtropical regions into the northeastern Pacific,

known as "El Niño" events, may cause olive ridleys to migrate north where they "cold stun"

once they encounter colder water. El Niño events can also cause reduced food production for

some turtle species which can reduce growth and fecundity. (see Recovery - Sections 2.1.6,

2.1.7, 2.2.1, 2.2.2)
20

14. Disease and Parasites

There are few data to assess the extent to which disease or parasitism affects the

survivability of sea turtles in the wild. Contact with cold water currents in the northeastern

Pacific may cause cold-stunning and make turtles more susceptible to disease. Stranded

individuals have been found along the U.S. coast in an emaciated condition (Joe Cordaro,

NMFS, pers. comm.)

15. Algae, Seagrass, and Reef Degradation

Most sea turtle species depend upon sea grass and/or coral reef habitats for food and

refuge. The destruction or degradation of these habitats is a widespread and serious threat to

the recovery of depleted sea turtle stocks. The general degradation of these habitats can be

affected by eutrophication, sedimentation, chemical poisoning, collecting/gleaning, trampling

(fishermen, skin and SCUBA divers), anchoring, etc. (see Recovery - Section 2.2)

16. Environmental Contaminants

Chemical contamination of the marine environment due to sewage, agricultural runoff,

pesticides, solvents and industrial discharges is widespread along the coastal waters of the

western U.S., particularly near the populated coastal areas of southern California. Declining

productivity of benthic communities can negatively impact the olive ridley turtles that depend

on these communities for nutrition. (see Recovery - Section 2.2)

17. Debris (Entanglement and Ingestion)

The entanglement in and ingestion of persistent marine debris threatens the survival of

olive ridley turtles in the eastern Pacific. Turtles become entangled in abandoned fishing gear,

lines ropes and nets, and cannot submerge to feed or surface to breathe; they may lose a limb

or attract predators with their struggling. Turtles will also ingest debris such as plastic bags,

plastic sheets, plastic six-pack rings, tar balls, styrofoam, and other refuse. Necropsies of

stranded turtles have revealed mortalities due to ingested garbage resulting in poisoning or

obstruction of the esophagus. (see Recovery - Section 2.1.3)

18. Fisheries (Incidental Take) 

Turtles are accidentally taken in several commercial and recreational fisheries. These

include bottom trawls commonly used by shrimp vessels in the Gulf of California, gillnets,

traps, pound nets haul seines and beach seines commonly used in inshore and coastal waters

of Baja California. In addition, trawls, purse seines, hook and line, driftnets, bottom and

surface longlines may kill an as yet unknown number of turtles in different areas of the eastern

Pacific. IATTC (unpublished data) reported turtles - mostly unidentified but probably olive

ridleys or greens - feeding directly off bait (usually shark or dorado) used by tuna fishermen. 

Olive ridleys comprised 18% of the annual take of all species of sea turtles by the Hawaiianbased longline fishery observed from 1990-1994 (NMFS 1995). The predicted annual take of

olive ridleys by this fishery is 152 turtles. Although most are released alive, the level of postrelease mortality remains unknown. (see Recovery - Section 2.1.4)
21

19. Predation

Large coastal and pelagic sharks and killer whales are common in the northeastern Pacific

and pose a potential threat to adults and juvenile turtles.

On two occasions in 1992, groups of killer whales were observed feeding on an olive ridley

off the coast of Mexico (Esquivel et al. 1993).

20. Boat Collisions

Sea turtles can be injured or killed when struck by a boat, especially if struck by an

engaged propeller. Recreational equipment, such as jet skis, also pose a danger due to

collisions and harassment. (see Recovery - Section 2.1.4, 2.1.5, 2.1.7)

21. Marina and Dock Development

The development of marinas and private or commercial docks in inshore waters can

negatively impact turtles through destruction or degradation of foraging habitat. This type of

development also leads to increased boat traffic resulting in collision-related injury and

mortality of turtles. Fueling facilities at marinas can result in discharge of oil and gas into

sensitive estuarine habitats. There is increasing demand to install marinas and docks and

develop inland coastal areas where turtles are known or are likely to exist in Baja California

and southern California. (see Recovery - Sections 1.2.1, 2.2)

22. Dredging

Active dredging machinery (especially hopper dredges) may injure or kill sea turtles, and

channelization may alter natural current patterns and sediment transportation. Coral reef and

sea grass ecosystems may be excavated and lost, and suspended materials may smother

adjacent coral and seagrass communities. (see Recovery - Section 2.2)

23. Dynamite “Fishing”

 The use of explosives to stun or kill fish destroys coral, degrading or eliminating foraging

habitat and refugia for all sea turtle species (except the leatherback) as well as killing turtles

directly. (see Recovery - Section 2.2)

24. Oil Exploration and Development

Oil exploration and development pose direct and indirect threats to sea turtles. A rise in

transport traffic increases the amount of oil in the water from bilge pumping and disastrous oil

spills. Oil spills resulting from blow-outs, ruptured pipelines, or tanker accidents, can result in

death to sea turtles. Indirect consequences include destruction of foraging habitat by drilling,

anchoring, and pollution. (see Recovery - Section 2.2)
22

25. Power Plant Entrapment 

The entrainment and entrapment of juvenile and sub-adult turtles in the saltwater cooling

intake systems of coastal power plants have been documented in southern California at San

Diego Gas & Electric (SDG&E) plant at Carslbad, as well as the Southern California Edison

Nuclear Generating Station at San Onofre (Kent Miles, SDG&E, pers. comm., Joe Cordaro,

pers. comm.). Some of these turtles are released unharmed.

26. Construction Blasting

Blasting can injure or kill sea turtles in the immediate area. The use of dynamite to

construct or maintain harbors, break up rock formations or improve nearshore access can

decimate sea turtle habitat. Anchoring and related activities employed in support of the

blasting can also degrade reefs and other benthic communities that support sea turtles. Some

types of dynamiting have minimal impact to marine life, such as placing explosive in pre-drilled

holes (drilling and shooting) prior to detonation. This is the standard practice to secure armor

rock. (see Recovery - Section 2.2)
23

I. Conservation Accomplishments

The olive ridley is classified as Endangered according to the International Union for

Conservation of Nature and Natural Resources (IUCN) Red Data Book (Groombridge 1982),

and is listed in Appendix I of CITES. According to the Code of Federal Regulations (50 CFR

17.11), under the ESA nesting populations of olive ridleys along the Pacific coast of Mexico

are protected as Endangered and all others are listed as Threatened. 

Until 1959 the harvest of olive ridleys in Mexico was primarily for local consumption by local

coast-dwelling peoples which included the Seris (from Sonora), the Huaves (from Sinaloa) and

the Pomaros (from Michoacan). After 1959 a commercial market primarily for meat and leather

was established and thus increased the need for regulatory control of the harvest. Up until this

increase in commercial use, fisheries’ regulations forbade the harvest of eggs (est. 1927) and

established a legal season for the harvest of turtles (est. 1929). After 1960, protection

programs and research camps were established on the nesting beaches, and by 1968 a

franchise system was established to further regulate olive ridley harvests. The franchise

system turned over responsibility for the harvest of turtles to fisheries’ cooperatives, who were

responsible for monitoring turtle harvest. Olive ridleys subsequently represented 90% of all

turtles harvested and 5% of the entire fishery production for Mexico. By 1986, declines in olive

ridley nesting populations, and the apparent lack of control by the cooperatives forced the

government of Mexico to establish 17 reserve areas for the protection of sea turtles. These

areas included the primary nesting beaches for the olive ridley including Ceuta and El Verde in

Sinaloa, Mismaloya, Teopa and Cuitzmala in Jalisco; Maruata, Colola and Mexiquillo in

Michoacan; Piedra de Tlacoyunque and Tierra Colorada in Guerrero; Chacahua and Escobilla

in Oaxaca and Puerto Arista in Chiapas. Establishment of these reserves and the subsequent

stationing of military guards at these beaches reduced the harvest of olive ridleys. Finally in

1990, a total prohibition on sea turtle harvest and the additional establishment of protection

camps has further reduced the take of olive ridleys in Mexico.
24

II. RECOVERY

A. Recovery Objectives

Goal: The recovery goal is to delist the species.

Recovery Criteria: To consider delisting all of the following recovery criteria must be met:

1) All regional stocks that use U.S. waters have been identified to source beaches based

on reasonable geographic parameters.

2) Foraging populations are statistically significantly increasing at several key foraging

grounds within each stock region. 

3) All females estimated to nest annually (FENA) at "source beaches" are either stable or

increasing for over 10 years. 

4) A management plan based on maintaining sustained populations for turtles is in effect.

5) International agreements are in place to protect shared stocks. 

Rationale: Determining quantifiable values that can be used to determine when a sea turtle

stock is recovered is quite difficult. The recovery team has tried to make such

recommendations as listed above based on best available information with the following

conceptual guidelines:

1) The minimum nesting stock must equal a size that could not easily be eliminated by a

single catastrophic event ("natural" or "man induced").

2) Nesting population trends should be long enough to minimize the effects of natural

fluctuations in numbers that are characteristic of sea turtle populations. Generally this time

period is equal to the estimated one generation time for each species.

3) Habitats are adequate to support population growth once threats have been reduced or

eliminated.

4) If a species is to be considered for delisting, a plan must already be in force for

maintaining the population in stable or increasing condition. The team was concerned that

if a species was delisted, and no management plan was already in force, that the species

may be driven back toward extinction too rapidly for resource management agencies to

implement such plans.
25

B. Step Down Outline and Narrative for Recovery

1 NESTING ENVIRONMENT

While it is recognized that there is no nesting by this species in U.S. jurisdiction, we felt that a

description of recovery actions should be provided so that U.S. agencies could take them into

account when providing support to those nations in which U.S. stocks may nest.

1.1 Protect and manage turtles on nesting beaches.

It is prudent to preserve the capacity of a population to recover from a depleted state by

protecting nesting females, their nests and hatchlings and to preserve the quality of the

nesting area. The killing of gravid females, poaching of nests, predation (native and feral),

destruction of the habitat through mining, destruction of vegetation, artificial lighting,

development, and increased human use all degrade the ability of depleted populations to

recover. Although there are no known nesting grounds for olive ridleys in the U.S. Pacific,

we support the efforts of Mexico and Central American nations with nesting grounds to

preserve their olive ridley nesting populations. The following tasks may be used as

guidelines to enhance the reproductive ability of sea turtle populations at the nesting

grounds. 

1.1.1 Eliminate directed take of turtles and their eggs.

Direct take of nesting turtles and their eggs has been identified as a primary

threat to Pacific sea turtle populations. Eliminating this threat is required if

populations are to recover.

1.1.1.1 Reduce directed take of turtles through public education and information.

While increased law enforcement will be effective in the short term,

without support of the local populace, regulations will become ineffective. 

Education of the public as to the value of conserving sea turtles, is a

very effective way of sustaining recovery efforts and providing support

for enforcement of management regulations. Where egg harvests are

still important to the local culture, egg harvests may be managed on

arribadas. (Also see Section 4)

1.1.1.2 Increase enforcement of laws protecting turtles by law enforcement and the

courts.

Lack of adequate support for law-enforcement activities which protect

sea turtle populations is common, yet it must be understood that

enforcement is as important as any other resource management

activities. Enforcement, judicial, and prosecutorial personnel must

receive adequate resources as well as instruction about sea turtles and

the importance of protecting turtle populations.
26

1.1.2 Ensure that coastal construction activities avoid disruption of nesting and

hatching activities.

Coastal construction must be monitored to minimize impact on turtle beaches,

both during construction, particularly during the nesting and hatching season,

and in the long-term. Construction equipment must not be allowed to operate

on the beach, remove sand from the beach, or in any way degrade nesting

habitat. Nighttime lighting of construction areas should be prohibited during

nesting and hatching seasons. In the long-term, structures should not block the

turtle’s access to the beach, change beach dynamics, or encourage human

activities that might interfere with the nesting process.

1.1.3 Reduce nest predation by domestic and feral animals.

Feral animals such as dogs pose a severe threat to turtle nests and hatchlings. 

It is important that feral predators be controlled or eliminated from nesting areas. 

Domestic animals such as pigs or dogs can also threaten turtle nests and

hatchlings, and should be controlled near nesting areas. In particular, domestic

dogs should not be allowed to roam turtle nesting beaches unsupervised.

1.1.4 Reduce effects of artificial lighting on hatchlings and nesting females.

Because sea turtles (especially hatchlings) are strongly attracted to artificial

lighting, lighting near nesting beaches should be placed in such a manner that

light does not shine on the beach. If not, turtles may become disoriented and

stray from their course.

1.1.4.1 Quantify effects of artificial lighting on hatchlings and nesting females.

It is important to quantify the impact of existing lighting in terms of

nesting success and hatchling survival so that pragmatic mitigation can

be applied. Also such study can be used to guide the development of

effective lighting ordinances. 

1.1.4.2 Implement, enforce, evaluate lighting regulations or other lighting control

measures where appropriate.

Shielding of the light source, screening with vegetation, placing lights at

lowered elevations and in some cases the use of limited spectrum low

wavelength lighting (e.g., low pressure sodium vapor lights) are possible

solutions to beach lighting problems. Such measures should be required

by law and enforced.

1.1.5 Collect biological information on nesting turtle populations.

The collection of basic biological information on nesting is critical for making

intelligent management decisions. Monitoring nesting success can help to

identify problems at the nesting beach or elucidate important areas for
27

protection. Analyzing population recruitment can help in understanding

population status.

1.1.5.1 Monitor nesting activity to identify important nesting beaches, determine number

of nesting females, and determine population trends.

Important nesting beaches (based on actual number of nests) must be

identified for special protection. Nesting beaches need to be identified by

standardized surveys during the nesting season. Informational surveys

with local residents and officials should be conducted to determine

current or historical nesting beaches.

One of the most crucial techniques for determining the status of sea

turtle populations and for evaluating the success of management or

restoration programs is long-term monitoring of annual nesting on key

beaches. The surveys must be done in a standardized and consistent

manner with experienced personnel. However, because of long maturity

times for turtles, quantifying trends in population sizes and effectiveness

of any restoration program may take a generation time (20+ years) to be

reflected in the annual numbers of nesters. Monitoring should thus be

recognized as a long-term undertaking.

1.1.5.2 Evaluate nest success and implement appropriate nest-protection measures on

important nesting beaches.

One of the simplest means to enhance populations is by increasing

hatchling production at the nesting beach. The first step to such an

enhancement program is to determine the nesting / hatching success

and to characterize factors which may limit that success. Once those

limiting factors are determined, protection or mitigation measures can be

implemented. If nests must be moved to prevent loss from erosion or

other threats, natural rather than artificial incubation should be

employed.

1.1.5.3 Define stock boundaries for Pacific sea turtles.

Because sea turtles exhibit a unique genetic signature for each major

nesting assemblage, and because nesting assemblages provide an

easily censused means of monitoring population status, it is useful to

use genetic analysis methods to determine stock boundaries for sea

turtle populations. It also enables managers to determine which stocks

are being impacted by activities far removed from the nesting beaches,

and thus prioritize mitigation efforts.

1.1.5.3.1 Identify genetic stock type for major nesting beach areas.
28

A “genetic survey” to establish the genetic signature of each

nesting population must be established, before stock ranges can

be determined. Such surveys are relatively simple as they

require only a small blood sample from a statistically viable

number of females within each nesting population.

1.1.5.3.2 Determine nesting beach origins for juvenile and subadult populations.

Because nesting populations can form the basis for stock

management, it is important to be able to pair juvenile and

subadult turtles with their stock units by genetic identification. 

DNA analyses have begun to provide scientists and managers

with this sort of data. 

1.1.5.3.3 Determine the genetic relationship among Pacific olive ridley

populations.

The need for such study is critical to successful management of a

sea turtle population as it enables resource managers to identify

the entire (and often overlapping) range of each population. This

type of population study can also detail the genetic diversity and

viability of the populations. Genetic analyses also have a forensic

application that can 1) support law enforcement efforts to identify

the source of illegal sea turtle products (eggs and meat) (see

Section 2.1.1.2) and 2) identify originating stock of confiscated or

stranded live animals for rehabilitation purposes (see Section

3.3).

1.2 Protect and manage nesting habitat.

The nesting habitat must be protected to ensure future generations of the species. 

Increased human presence and coastal construction can damage nesting habitat resulting

in reduced nest success or reduced hatchling survival.

Once key nesting beaches are identified, they may be secured on a long-term basis in an

assortment of ways. These may include conservation easements or agreements, lease of

beaches, and in some cases, fee acquisition. Certain beaches may be designated as

natural preserves. In some cases education of local residents may serve to adequately

secure nesting beaches.

1.2.1 Prevent the degradation of nesting habitats caused by sea walls, revetments,

sand bags, other erosion-control measures, jetties and breakwaters. 

Beach armoring techniques that beach residents use to protect their beachfront

properties from wave action may actually degrade nesting habitats by eroding

beaches and preventing nesting by preventing access to nesting sites or

preventing digging of the nest on the site. Guidelines on the proper placement
29

of stonewalls must be proposed. Jetties and breakwaters impede the natural

movement of sand and add to erosion problems in neighboring beaches. 

Regulations regarding beach construction and beach armoring should be

reviewed to ensure that such measures are restricted or prohibited if adverse

impacts to nesting are anticipated.

1.2.2 Eliminate sand and coral rubble removal and mining practices on nesting

beaches.

Beach mining severely affects a nesting beach by reducing protection from

storms, destroying native vegetation directly or indirectly and may completely

destroy a nesting beach. Protective legislation and public education must be

used to protect the substrate of the beaches.

1.2.3 Develop beach-landscaping guidelines which recommend planting of only native

vegetation, not clearing stabilizing beach vegetation and evaluating the effects

as appropriate.

Non-native vegetation may prevent access to nesting sites, prevent adequate

nest digging, exacerbate erosion or affect hatchling sex ratios by altering

incubation temperatures. Native vegetation, however, plays an important role in

stabilizing the beach and creating the proper microclimate for nests. Guidelines

for residents concerning the most appropriate plant species and the importance

of a native plant base should be encouraged.

1.2.4 Ensure that beach replenishment projects are compatible with maintaining good

quality nesting habitat.

Sand on sea turtle beaches has particular properties which affect hatching

success (ie. compaction, gas diffusion, temperature). Any addition or

replacement of sand may change these properties and make it more difficult for

females to nest or reduce hatchling success. As such, beach replenishment

projects should be carefully considered, use materials similar to the native

sands and be carried out outside the nesting season. 

1.2.5 Implement non-mechanical beach cleaning alternatives.

Hand raking of beach debris, rather than using heavy machinery, should be

encouraged on nesting beaches where cleaning is done for aesthetic reasons. 

The use of heavy machinery can adversely affect hatchlings directly and their

nesting habitat. 

1.2.6 Prevent vehicular driving on nesting beaches.

Driving on active nesting beaches should be forbidden. Vehicles cause

destabilization of beaches, threaten incubating nests and leave tire ruts that

hatchlings have difficulty crossing.
30

2 MARINE ENVIRONMENT

2.1 Protect and manage olive ridley populations in the marine habitat.

Protection of turtles in the marine environment is a priority that is often overlooked as

enforcement is difficult and quantification of the problem problematic. However, 99% of a

turtle’s life is spent at sea; thus, recovery must include significant efforts to protect turtles at

that time.

2.1.1 Eliminate directed take of turtles.

Direct take of turtles was identified as a severe threat to population recovery in

the Pacific Ocean and must be eliminated if sea turtles are to recover.

2.1.1.1 Reduce directed take of turtles through public education and information.

While increased law enforcement will be effective in the short term,

without support of the local populace, regulations will become ineffective. 

Education of the public as to the value of conserving sea turtles, is a

very effective way of sustaining recovery efforts and providing support

for enforcement of management regulations. (Also see Section 4)

2.1.1.2 Increase the law-enforcement efforts to reduce illegal exploitation.

One of the major threats identified for turtle populations in the Pacific

was the illegal harvest of turtles, primarily for turtle leather export, both

on the nesting beach and in the water. Rigorous efforts in law

enforcement should be undertaken immediately to reduce this source of

mortality. Such efforts need to include training of enforcement personnel

in the importance of protecting turtles, as well as supplying such

personnel with adequate logistical support (boats, communication and

surveillance equipment etc.). Judges and prosecutors must also be

educated in the importance of these matters. Trade in sea turtle

products and other curio must also be restricted.

2.1.2 Determine distribution, abundance, and status in the marine environment.

In its review of information on sea turtle populations in the Pacific, the Recovery

Team found that lack of accurate information on distribution and abundance

was one of the greatest threats to sea turtle populations. Most existing

information is anecdotal or obsolete and where new information is available, it

uniformly indicates that olive ridley populations are vastly smaller than

commonly believed. We consider that gathering of basic information on

distribution and abundance should take a very high priority in the recovery of

Pacific olive ridley populations.

2.1.2.1 Determine the distribution and abundance of post-hatchlings, juveniles and

adults.
31

While little is known about the distribution of nesting beaches for the

olive ridley, even less is understood about distribution of foraging adult

and juvenile populations. Quantitative surveys of foraging areas to

determine olive ridley abundance, and to identify essential habitat is of

significant importance for restoration of olive ridley populations.

2.1.2.2 Determine adult migration routes and internesting movements.

Like all species of sea turtle, with the possible exception of the Flatback

turtle, Natator depressus), olive ridleys migrate from foraging grounds to

nesting beaches. Though we do have some data on their movements,

indicating seasonal north south migrations or at sea migrations between

a series of feeding areas, their movements need further clarification. 

These migrations often mean that the turtles move through a variety of

political jurisdictions where regulations regarding the stewardship of the

species may vary. To preclude the problem of contradictory

management strategies by these various jurisdictions, it is important to

determine the migration routes olive ridleys follow between nesting and

foraging areas. Satellite telemetry studies of both males and females

are needed.

2.1.2.3 Determine growth rates and survivorship of hatchlings, juveniles, and adults,

and age at sexual maturity.

Understanding the rates of growth and survivorship of turtle populations

is crucial to the development of appropriate population models. Such

models are important in understanding population status and how best to

efficiently apply management efforts, in restoring depleted populations.

For example, the application of stage-based modeling (Crouse et al.

1987) indicated that not enough effort was being expended on protecting

juvenile sized loggerhead sea turtles in the southeastern United States

and that without such protection, extensive nesting beach protection was

having less positive benefit. A similar approach to understanding olive

ridley populations should be undertaken, and used to guide restoration

policy.

2.1.2.4 Identify current or potential threats to adults and juveniles on foraging grounds.

Little is known about threats to foraging populations of olive ridleys. 

Studies on such threats should be undertaken immediately.

2.1.3 Reduce the effects of entanglement and ingestion of marine debris.
32

Entanglement due to abandoned or unmonitored fishing gear, as well as the

ingestion of man-made debris is a significant problem in the marine

environment. 

2.1.3.1 Evaluate the extent to which sea turtles ingest persistent debris.

Quantification of the extent to which sea turtles are impacted by marine

debris should be undertaken as a first step to mitigating or preventing

such impacts. The benefits of such work are that it allows the

prioritization of recovery activities and it allows the activities to be

efficiently targeted at the problem. 

2.1.3.2 Evaluate the effects of ingestion of persistent debris on health and viability of

sea turtles.

Because of the remote nature of turtle/debris interactions, the acute and

chronic effects of such interaction are not often understood. Turtles may

not die immediately after ingesting certain materials, but may become

debilitated. Studies to further understand the impacts of such

interactions, and what age classes are affected most severely, should be

undertaken immediately. As with quantifying the extent to which sea

turtles ingest debris, such a program allows recovery efforts to be more

efficient.

2.1.3.3 Formulate and implement measures to reduce or eliminate persistent debris in

the marine environment.

Once the problem of marine debris has been identified and quantified, it

is important to implement (and enforce) a program to reduce the amount

of debris in the marine environment, ie. removing the problem entirely,

as contrasted with mitigating the problem.

2.1.4 Monitor and reduce incidental mortality in the commercial and recreational

fisheries.

 For some areas, incidental take in fisheries has been identified as a severe

threat. These mortalities are associated with international fleets operating on

the high seas and U.S. tuna purse seine fisheries (minimal). Monitoring of turtle

take by fisheries is extremely important for two reasons. First, it allows resource

managers a means to quantify the extent of the problem, and by the very act of

monitoring, tends to cause commercial fishermen to be more aware of the

concern over incidental take, and thereby encourage reduced take. The choice

method for monitoring take is through the use of an unbiased observer program. 

Voluntary logbooks have not proven a reliable technique for quantifying

incidental catch in commercial fisheries. Implementation of mortality reduction

activities includes the use of Turtle Excluder Devices (TED) in shrimp trawler

fisheries. 
33

2.1.5 Eliminate the harassment of turtles at sea.

Activities such as “petting” turtles and chasing them while snorkeling and scuba

diving, water skiing, jet skis, vessel traffic, and vessel anchoring may disturb or

displace turtles. These factors should be regulated or controlled to eliminate

negative impacts, especially in sensitive and high density foraging and resting

areas.

2.1.6 Study the impact of diseases on turtles.

Little is known about diseases in sea turtles, but there has been recent evidence

that it may be a limiting factor in certain populations.

2.1.7 Maintain carcass stranding network.

Stranding networks are operated generally by volunteers who monitor beaches

for stranded animals. Such networks can be useful for alerting managers to

incidents causing high mortality, such as an increased fishery take or disease

problems, as well as providing some basic biological data. 

2.1.8 Centralize administration and coordination of tagging programs.

In general, government resource management agencies can provide the

continuity required to coordinate tagging programs. The responsibility of any

such agency is that they act as a central distribution point for tags, tagging

training and database management. It is critically important that the

coordinating agency: 1) provides adequate staff to keep the program organized

and respond to tag returns immediately, and 2) remain in existence for many

years (20+). Without such a commitment, tagging programs have very limited

usefulness, and before initiation of such a program it should be considered

carefully on its scientific merits. It must be remembered that sea turtles are

long-lived animals, and the most valuable information yielded by any tagging

program comes from turtles which have carried identification tags for many

years. Short-term tagging projects are at best very limited in the information

they yield and at worst are nothing more than a form of undue harassment to

the turtles. 

Centralization of tag records is useful as it makes the most efficient use of

limited personnel resources, allows standardization of techniques, and can act

as a screening mechanism to ensure that tagging is done for valid scientific

reasons.

2.2 Protect and manage marine habitat, including foraging habitats.

Olive ridleys inhabit a variety of marine habitats, although we are most familiar with their

coastal habitat. Increased human presence in this and other sea turtle habitats have

contributed to degradation, primarily by coastal construction, increased recreational and
34

fisheries use, and increased industrialization. Habitat loss and degradation must be

prevented or slowed.

2.2.1 Identify important marine habitats.

These areas may include hatchling (pelagic algal mats), juvenile and adult

foraging areas and migratory range for all age classes. (Many of these areas

will first need to be identified through actions in Section 2.1.2.1 and 2.1.2.2.)

2.2.2 Ensure the long-term protection of marine habitat.

Once marine habitats are identified, sea turtle range, refugia and foraging

habitats (Sargassum beds, coral reefs and sponge habitats) need to be

protected to ensure long-term survival for the species. Habitats identified as

important or critical should be designated as marine sanctuaries or preserves,

while others may require close monitoring. The public needs to be educated on

the importance of preserving these habitats.

 

2.2.3 Identify other threats to marine habitat and take appropriate actions.

Such threats to sea turtle habitats that do not fit in the previous sections or new

threats must be considered and addressed. Such threats may include

commercial and recreational illegal takes of coral and “live rock” for aquaria, as

well as take of tropical fish for aquaria. Chemicals used to capture the fish may

indirectly affect reefs.

3 ENSURE PROPER CARE IN CAPTIVITY.

Depending on the scale of such activities such captivity can be harmful to the wild

population due to excess take from the wild, or from the potential introduction of exotic

diseases or unfit genetic stocks to the wild population. Captive care should be carefully

regulated to minimize such problems, and all release programs should rigorously monitor

the status of released turtles to ensure their proper integration into the wild. It should be

noted that to be deemed successful, captive-reared turtles that have been released to the

wild should be shown not only to survive in the wild but should also successfully reproduce. 

 If released turtles do not reproduce, such populations will never be self sustaining. 

3.1 Develop standards for the care and maintenance of sea turtles, including diet, water

quality, tank size, and treatment of injury and disease.

Standards should be developed by NMFS or other appropriate agencies. Once developed,

these criteria should be published and set as requirements for any sea turtle holding

facility. Facilities that comply with the criteria will receive permits to hold turtles and be

inspected for compliance. A manual for diagnosis and treatment of sea turtle diseases

should be compiled, published and distributed to holding facilities. 
35

3.2 Establish a catalog of all captive sea turtles to enhance use for research and

education.

The FWS and NMFS should establish a catalog of turtles at all known facilities

and include basic biological data and genetic origin.

3.3 Designate rehabilitation facilities.

FWS, NMFS and other appropriate agencies should designate these facilities

based on the above criteria. Designation should be based on availability of

appropriate veterinary personnel, compliance with standards of care and annual

inspections. Recommendations should be made on when and where hatchlings

or adults should be released.

4 INTERNATIONAL COOPERATION

4.1 Support existing international agreements and conventions to ensure that turtles in all lifestages are protected in foreign waters.

Considering that olive ridleys migrate outside of U.S. territorial waters during at least part of

their life cycle, an effective recovery plan must include supporting existing cooperative

agreements with other nations to protect the species. Existing agreements include CITES

(see next section, adopted 1973), the Convention on Nature Protection and Wildlife

Preservation in the Western Hemisphere (adopted 1940), the ASEAN Agreement on the

Convention of Nature and Natural Resources (adopted 1985), the Convention for the

Protection of the Natural Resources and Environment of the South Pacific Region (SPREP

convention, adopted 1986), as well as a number of conventions concerning marine

pollution (Eckert, 1993). 

4.2 Encourage ratification of the CITES for all non-member Pacific countries, compliance with

CITES requirements, and removal of sea turtle trade reservations held by member nations.

CITES is a comprehensive wildlife treaty signed by many countries that regulates and 

prohibits commercial import and export of wild plant and animal species that are threatened

by trade. In the north Pacific signatories include 18 countries (Eckert, 1993). It is one of

the most powerful international agreements concerning threatened species. The U.S.

State Department, Department of Commerce and Department of Interior should work with

Pacific nations to encourage non-member countries to become signatories and demand

compliance with CITES requirements on sea turtles from all signatories.

4.3 Develop new international agreements to ensure that turtles in all life-stages are

protected in foreign waters.

New agreements must be outlined by the FWS and NMFS, and pursued by the State

Department and Department of the Interior. Eastern Pacific nations should be encouraged

to ratify the Regional Agreement for Investigation and Management of Marine Turtles of the

American Pacific which was not put into place after being drafted in 1986.
36

4.4 Develop or continue to support informational displays in airports which provide connecting

legs for travelers to the areas which support olive ridleys.

Airports are particularly good avenues for information about illegal trade in tortoise and

tortoiseshell paraphernalia, as well as general information on sea turtle conservation. If

travelers don’t purchase the items, the market for them may decrease. Agencies such as

NMFS, FWS and the U.S. Customs Service should collaborate on display content and

placement.
37

III. REFERENCES CITED

Amorocho, D., H. Rubio T., and W. Diaz R. 1989. Observaciones sobre el estado actual de

las tortugas marinas en el Pacifico Colombiano. Unpubl. rept. to World Wildlife Fund. 

Arenas, P., and M. Hall. 1992. The association of sea turtles and other pelagic fauna with

floating objects in the eastern tropical Pacific Ocean. Pages 7-10 in M. Salmon and J.

Wyneken (compilers), Proc. Eleventh Annual Workshop on Sea Turtle Biology and

Conservation. U.S. Dep. Comm., NOAA Tech. Memo. NMFS-SEFSC-302. 195 pp.

Aridjis, H. 1990. Mexico proclaims total ban on harvest of turtles and eggs. Mar. Turtle

Newsl. 50:1-3.

Arauz-Almengor, M., C.L. Mo, and E. Vargas M. 1993. Preliminary evaluation of olive ridley

egg commerce from Ostional Wildlife Refuge, Costa Rica. Mar. Turtle Newsl. 63:10-13.

Bailey, M., and M. Bailey. 1974. Staying Alive! David McKay Co., New York.

Balazs, G.H 1982a. Status of sea turtles in the central Pacific Ocean. Pages 243-252 in K.A.

Bjorndal (ed.), Biology and Conservation of Sea Turtles. Smithsonian Inst. Press,

Washington, D.C. 583 pp.

Balazs, G.H. 1982b. Annotated bibliography of sea turtles taken by longline fishing gear. 

Unpubl. report.

Balazs, G.H. 1983. Status review document for Pacific sea turtles. NOAA/NMFS/SWFSC

Admin. Rept. H-83-17. 6 pp.

Balazs, G.H. 1985. Impact of ocean debris on marine turtles: Entanglement and ingestion.

Pages 387-429 in R.S. Shomura and H.O. Yoshida (eds.), Proceedings of the

Workshop on the Fate and Impact of Marine Debris, 26-29 November 1984, Honolulu,

HI. U.S. Dep. of Comm., NOAA Tech. Memo. NMFS-SWFC-054.

Balazs, G.H., and S. Hau. 1986. Geographic distribution: Lepidochelys olivacea in Hawaii.

Herpetol. Rev. 17(2):51.

Bowen, B.W., A.B. Meylan, and J.C. Avise. 1991. Evolutionary distinctiveness of the

endangered Kemp's ridley sea turtle. Nature 352:709-711.

Brown, C.H., and W.M. Brown. 1982. Status of sea turtles in the southeastern Pacific:

emphasis on Peru. Pages 235-240 in K.A. Bjorndal (ed.), Biology and Conservation of

Sea Turtles. Smithsonian Inst. Press, Washington, D.C. 583 pp.

Bustard, R. 1972. Australian Sea Turtles, Their Natural History and Conservation. William

Collins Sons and Co., Ltd., London. 220 pp.
38

Caldwell, D.K. 1969. Pacific ridley sea turtle Lepidochelys olivacea in Puerto Rico. Bull.

South. Calif. Acad. Sci. 68(2): 11.

Caldwell, D.K., and R.S. Casebeer. 1964. A note on the nesting of the eastern Pacific ridley

sea turtle, Lepidochelys olivacea. Herpetologica 20:213.

Carr, A.F. 1952. Handbook of Turtles. Cornell Univ. Press, Ithaca, NY. 529 pp.

Carr, A. 1961. The ridley mystery today. Animal Kingdom 64:7-12.

Carr, A. 1972. Great reptiles, great enigmas. Audubon 74:24-34.

Carr, A. 1987. Rips, FADS, and little loggerheads. BioScience 36:92-100.

Carr, T., and N. Carr. 1991. Surveys of turtles of Angola. Biol. Conserv. 58:19-29.

Cliffton, K., D.O. Cornejo, and R.S. Felger. 1982. Sea turtles of the Pacific coast of Mexico.

Pages 199-209 in K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles.

Smithsonian Inst. Press, Washington, D.C. 583 pp.

Cornelius, S.E. 1975. Marine turtle mortalities along the coast of Costa Rica. Copeia

1975(1):186-187.

Cornelius, S.E. 1976. Marine turtle nesting activity at Playa Naranjo, Costa Rica. Brenesia

8:1-27.

Cornelius, S.E. 1982. Status of sea turtles along the Pacific coast of Middle America. Pages

211-219 in K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles. Smithsonian

Inst. Press, Washington, D.C. 583 pp.

Cornelius, S.E., and D. Robinson. 1983. Abundance, distribution, and movements of olive

ridley sea turtles in Costa Rica, III. U.S. Fish Wildl. Serv. Endangered Species Rept. 13,

Albuquerque, NM.

Cornelius, S.E., and D.C. Robinson. 1986. Post-nesting movements of female olive ridley

turtles tagged in Costa Rica. Vida Silvestre Neotropical 1:12-23.

Cornelius, S.E., M. Alvarado U., J. Carlos C., M. Mata D.V., and D.C. Robinson. 1991.

Management of olive ridley sea turtles (Lepidochelys olivacea) nesting at Playas

Nancite and Ostional, Costa Rica. Pages 111-135 in J.G. Robinson and K.H. Redford

(eds.), Neotropical Wildlife Use and Conservation. University of Chicago Press,

Chicago.

Crouse, O.T., Crowder, L.B. and Caswell, H. 1987. A stage based population model for

loggerhead sea turtles and implications for conservation. Ecology 68(5):1412-1423.
39

Dundee, H.A. 1992. The etymological riddle of the ridley sea turtle. Mar. Turtle Newsl. 58:10-

12.

Deraniyagala, P.E.P. 1939. The tetrapod reptiles of Ceylon. Vol. 1. Testudinates and

crocodilians. Ceylon, Colombo Mus. Nat. Hist.

Eckert, K.L. 1993. The biology and population status of marine turtles in the north Pacific

Ocean. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-SWFSC-186. 156 pp.

Eckert, S.A., D.W. Nellis, K.L. Eckert, and G.L. Kooyman. 1986. Diving patterns of two

leatherback sea turtles (Dermochelys coriacea) during internesting intervals at Sandy

Point, St. Croix, U.S. Virgin Islands. Herpetologica 42(3): 381-388.

Esquivel, C., L. Sarti, and I. Fuentes. 1993. Primera observación directa documentada sobre

la depredación de la tortuga marina Lepidochelys oivacea por Orcinus orca. Cuad.

Mex. Zool. 1(2):96-98.

Frazier, J. 1983. Analisis estadistico de la tortuga golfina Lepidochelys olivacea (Eschscholtz)

de Oaxaca, Mexico. Ciencia Pesquera 4:49-75.

Frazier, J. 1985. Misidentifications of sea turtles in the east Pacific: Caretta caretta and

Lepidochelys olivacea. J. Herpetol. 19:1-11.

Frazier, J.G., H.L. Fierstine, S.C. Beavers, F. Achaval, H. Suganuma, R.L. Pitman, Y.

Yamaguchi and C. M. Prigioni. 1994. Impalement of marine turtles (Reptilia, Chelonia:

Chelonnidae and Dermochelyidae) by billfishes (Osteichthyes, Perciformes:

Istiophoridae and Xiphiidae). Environ. Biol. Fishes 39: 85-96.

Fritts, T.H. 1981. Pelagic feeding habits of turtles in the eastern Pacific. Mar. Turtle Newsl.

17:1.

Fritts, T.H., M.L. Stinson, and R. Márquez M. 1982. Status of sea turtle nesting in southern

Baja California, Mexico. Bull. South. Calif. Acad. Sci. 81:51-60.

Green, D., and F. Ortiz-Crespo. 1982. Status of sea turtle populations in the central eastern

Pacific. Pages 221-233 in K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles.

Smithsonian Inst. Press, Washington, D.C. 583 pp.

Groombridge, B. (compiler). 1982. The IUCN Amphibia-Reptilia Red Data Book, Part 1. Olive

ridley, pp. 209-223. Intl. Union for the Conservation of Nature and Natural Resources

(IUCN), Gland, Switzerland. 426 pp.

Higginson, J. 1989. Sea turtles in Guatemala: threats and conservation efforts. Mar. Turtle

Newsl. 45:1-5.

Hubbs, C.L. 1977. First record of mating of ridley turtles in California, with notes on

commensals, characters, and systematics. California Fish and Game 63(4):263-267.
40

Hughes, D.A., and J.D. Richard. 1974. The nesting of the Pacific ridley turtle Lepidochelys

olivacea on Playa Nancite, Costa Rica. Marine Biology 24:97-107.

Hurtado, M. 1981. Marine turtles recaptured in Ecuadorian waters. Bol. Inform., Inst. Nac.

Pesca, Guayaquil, Ecuador 2(5):18-23.

Hurtado, M. 1982. The ban on the exportation of turtle skin from Ecuador. Mar. Turtle Newsl.

20:1-4.

Lagueux, C.J. 1991. Economic analysis of sea turtle eggs in a coastal community on the

Pacific coast of Honduras. Pages 136-144 in J.G. Robinson and K.H. Redford (eds.),

Neotropical Wildlife Use and Conservation. University of Chicago Press, Chicago.

Landis, C.J. 1965. Research: new high pressure research animal? UnderSea Tech. 6:21.

Márquez M., R. 1990. Sea turtles of the world. An annotated and illustrated catalogue of sea

turtle species known to date. FAO Species Catalog, FAO Fisheries Synopsis

11(125):81 pp.

Márquez M., R., A. Villanueva, and C. Peñaflores. 1976. Sinopsis de datos biologicos sobre

la tortuga golfina. Instituto Nacional de Pesca, Sinopsis sobre la Pesca 2:1-61. 

Márquez M., R., C. Peñaflores S., A. Villanueva O., and J. Diaz F. 1982. A model for

diagnosis of populations of olive ridleys and green turtles of the west Pacific tropical

coasts. Pages 153-158 in K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles.

Smithsonian Inst. Press, Washington, D.C. 583 pp.

Meylan, A. 1982. Sea turtle migration - evidence from tag returns. Pages 91-100 in K.A.

Bjorndal (ed.), Biology and Conservation of Sea Turtles. Smithsonian Inst. Press,

Washington, D.C. 583 pp.

Minarik, C.J. 1985. Lepidochelys olivacea (olive ridley sea turtle) reproduction. Herp. Review

16(3):82.

Montenegro, S.B., N.G. Bernal, and A. Marinez G. 1986. Estudio del continedo estomacal de

la tortuga marina Lepidochelys olivacea, en la costa de Oaxaca, Mexico. An. Inst.

Cienc. del Mar y Limnol. UNAM, Mexico 13(2):121-132.

Mora, J.M., and D.C. Robinson. 1982. Discovery of a blind olive ridley turtle (Lepidochelys

olivacea) nesting at Playa Ostional, Costa Rica. Rev. Biol. Trop. 30(2):178-179.

Mortimer, J.A. 1982. Feeding ecology of sea turtles. Pages 103-109 in K.A. Bjorndal (ed.),

Biology and Conservation of Sea Turtles. Smithsonian Inst. Press, Washington, D.C. 

583 pp.

Mrosovsky, N. 1993. World's largest aggregation of sea turtles to be jettisoned. Mar. Turtle

Newsl. 63(Supplement):2-3.
41

National Marine Fisheries Service. 1995. Annual report on the biological opinion of June 25,

1994 concerning the take of sea turtles in the Hawaii longline fishery. Unpublished

report. 11 pp.

Nishimura, S. 1967. The loggerhead turtles in Japan and neighborhood waters (Testudinata:

Chelonidae). Publ. Seto Mar. Biol. Lab. 15(1):19-35.

Oliver, J.A. 1946. An aggregation of Pacific sea turtles. Copeia 2:103.

Pitman, R.L. 1990. Pelagic distribution and biology of sea turtles in the eastern tropical

Pacific. Pages 143-148 in T.H. Richardson, J.I. Richardson, and M. Donnelly

(compilers), Proc. of the Tenth Annual Workshop on Sea Turtle Biology and

Conservation. U.S. Dep. of Comm., NOAA Tech. Memo. NMFS-SEFC-278. 286 pp.

Pitman, R.L. 1992. Sea turtle associations with flotsam in the eastern tropical Pacific. Page

94 in M. Salmon and J. Wyneken (compilers), Proc. of the Eleventh Annual Workshop

on Sea Turtle Biology and Conservation. U.S. Dep. of Comm., NOAA Tech. Memo.

NMFS-SEFSC-302. 195 pp.

Pitman, R.L. 1993. Seabird associations with marine turtles in the eastern Pacific Ocean.

Colonial Waterbirds 16:194-201.

Plotkin, P.T., R.A. Byles, D.C. Rostal, and D.W. Owens. In Review. Independent versus

socially facilitated migration in olive ridley sea turtles Lepidochelys olivacea. Marine

Biology.

Plotkin, P.T., R.A. Byles, and D.W. Owens. 1994. Migratory and reproductive behavior of

Lepidochelys olivacea in the eastern Pacific Ocean. Page 138 in B.A. Schroeder and B.

E. Witherington (compilers), Proceedings of the Thirteenth Annual Symposium on Sea

Turtle Biology and Conservation. U.S. Dep. of Comm., NOAA Tech. Memo. NMFSSEFSC-341. 281 pp.

Pritchard, P.C.H. 1969a. Studies of the systematics and reproductive cycles of the genus

Lepidochelys. PhD Thesis, University of Florida, Gainesville. 196 pp.

Pritchard, P.C.H. 1969b. Sea turtles of the Guianas. Bull. Fla. State Mus. 13:85-140.

Pritchard, P.C.H. 1977. Marine turtles of Micronesia. Chelonia Press, San Francisco. 83 pp.

Pritchard, P.C.H., and P. Trebbau. 1984. The turtles of Venezuela. Society for the Study of

Amphibians and Reptiles, Contrib. Herpetol. No. 2.

Schulz, J.P. 1975. Sea turtles nesting in Surinam. Zoologische Verhandleingen, Lieden,

Netherlands. 144 pp. 

Smith, H.M., and R.B. Smith. 1979. Synopsis of the herpetofauna of Mexico. Vol. 6. John

Johnson, North Bennington, VT.
42

Stancyk, S.E. 1982. Non-human predators of sea turtles and their control. Pages 139-152 in

K. A. Bjorndal (ed.), Biology and Conservation of Sea Turtles. Smithsonian Inst. Press,

Washington, D.C. 583 pp.

Sternberg, J. 1981. The worldwide distribution of sea turtle nesting beaches. Sea Turtle

Rescue Fund, Center for Environmental Education, Washington, D.C. 7 pp.

Stinson, M.L. 1984. Biology of sea turtles in San Diego Bay, California, and in the

northeastern Pacific Ocean. Master's Thesis, San Diego State University. 578 pp.

Wibbels, T., D.W. Owens, and D. Rustal. 1991. Soft plastra of adult male sea turtles: an

apparent secondary sexual characteristic. Herpetol. Rev. 22(2): 42-48.

Woody, J.B. 1986. On the dollar value of the Oaxacan ridley fishery. Mar. Turtle Newsl.

36:6-7.

Zwinenberg, A.J. 1976. The olive ridley, Lepidochelys olivacea (Eschscholtz, 1829): probably

the most numerous marine turtle today. Bull. Maryland Herpt. Soc. 12:75-95.
43

IV. IMPLEMENTATION SCHEDULE

The Implementation Schedule outlines management and research actions and estimated costs

for the U.S. Pacific olive ridley turtle recovery program, as set forth in this recovery plan. It is a

guide for meeting the objectives discussed in Part II of this plan. This schedule indicates wherever

possible, task priority, task numbers, task descriptions, duration of tasks, the agencies responsible

for committing funds, and lastly, estimated costs. The agencies responsible for committing funds

are not, necessarily, the entities that will actually carry out the tasks. The actions identified in the

implementation schedule, when accomplished, should protect habitat for the species, stabilize the

existing populations, and increase the population sizes and numbers. Monetary needs for all

parties involved are identified to reach this point, whenever feasible.

Priorities in column 3 of the following Implementation Schedule are assigned as follows:

Priority 1 -

An action that must be taken to prevent extinction or to prevent the species from declining

irreversibly in the foreseeable future.

Priority 2 -

An action that must be taken to prevent significant decline in species population/habitat

quality or some other significant negative impact short of extinction.

Priority 3 -

All other actions necessary to provide for full recovery of the species.

KEY to Implementation Table Abbreviations:

CNMI = Commonwealth of the Northern Mariana Islands

COE = U.S. Army Corp of Engineers

DOC = U.S. Department of Commerce

DOI = U.S. Department of Interior

DOS = U.S. Department of State (primarily as a conduit for negotiations and

support for tasks in other political jurisdictions)

EPA = U.S. Environmental Protection Agency

FSM = Federated States of Micronesia

FWS = U.S. Fish & Wildlife Service

NA = Not applicable

NMFS = National Marine Fisheries Service

RMI = Republic of the Marshall Islands
A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 44 The lead agency is listed first.

IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

1.1 Protect & manage

turtles on nesting

beaches

1.1.1 Eliminate

directed take of

turtles and their eggs

1.1.1.1 Reduce

directed take through

public education &

information

(2) Continuing FWS, NMFS,

DOS

(No documented

nests under U.S.

jurisdiction)

Provide support

for international

information

exchange forum 

1.1.1.2 Law

enforcement-prevent

illegal exploitation &

harassment

(2) Continuing FWS, US

Customs, DOS,

NMFS

Encourage Mexico

and Central

American

countries to

support this task

1.1 Protect & manage

turtles on nesting

beaches (cont.)

1.1.2 Ensure coastal

construction activities

do not disrupt nesting

& hatching activities

(3) Continuing FWS, DOS,

NMFS

Encourage Mexico

and Central

American

countries to

support this task

1.1.3 Reduce nest

predation by domestic

& feral animals

(3) Continuing FWS, DOS Encourage Mexico

and Central

American

countries to

support this task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 45 The lead agency is listed first.

1.1 Protect & manage

turtles on nesting

beaches (cont.)

1.1.4 Reduce effects

of artificial lighting

on hatchlings &

nesting females

1.1.4.1 Quantify

effects of artificial

lighting

(3) Continuing FWS, DOS Encourage Mexico

and Central

American

countries to

support this task

1.1.4.2 Implement,

enforce, evaluate

lighting regulations

or other lighting

control measures

(3) Continuing Encourage Mexico

and Central

American

countries to

support this task

1.1 Protect & manage

turtles on nesting

beaches (cont.)

1.1.5 Collect

biological

information on

nesting populations

1.1.5.1 Monitor

nesting activity,

identify important

nesting beaches,

determine population

trends

(1) Continuing FWS, DOS,

NMFS

Encourage Mexico

and Central

American

countries to

support this task

1.1.5.2 Evaluate

nest success,

implement nestprotection measures

(1) Continuing FWS, DOS Encourage Mexico

and Central

American

countries to

support this task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 46 The lead agency is listed first.

1.1 Protect & manage

turtles on nesting

beaches (cont.)

1.1.5 Collect

biological

information on

nesting populations

(cont.)

1.1.5.3 Define stock

boundaries 

1 3 years NMFS, FWS 50 50 50 Includes Tasks

1.1.5.3.1-1.1.5.3.3

1.1.5.3.1 Identify

stock type for major

nesting beach areas

(1) 3 years NMFS, FWS,

DOS

1.1.5.3.2 Determine

nesting beach originsjuvenile & subadult

populations

1 3 years FWS, NMFS,

DOS

1.1.5.3.3 Determine

genetic relationship

among populations

1 3 years FWS, NMFS

1.2 Protect & manage

nesting habitat

1.2.1. Prevent

degradation due to

erosion-control

measures, jetties &

breakwaters

(3) Continuing FWS, DOS,

NMFS

Encourage Mexico

and Central

American

countries to

support this task

1.2.2 Eliminate sand,

coral rubble removal

& mining practices

(3) Continuing Encourage Mexico

and Central

American

countries to

support this task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 47 The lead agency is listed first.

1.2 Protect & manage

nesting habitat

(cont.)

1.2.3 Develop,

evaluate natural

beach-landscaping

guidelines

(3) Continuing FWS, DOS

.

Encourage Mexico

and Central

American

countries to

support this task

1.2.4 Ensure

replenishment

projects maintain

quality habitat

(3) Continuing Encourage Mexico

and Central

American

countries to

support this task

1.2.5 Implement nonmechanical beach

cleaning alternatives

NA NA

1.2.6 Prevent

vehicular driving on

nesting beaches

(3) Continuing Encourage Mexico

and Central

American

countries to

support this task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 48 The lead agency is listed first.

2.1 Protect & manage

populations in

marine habitat 

2.1.1 Eliminate

directed take of

turtles

2.1.1.1 Reduce

directed take through

education,

information

1 5 years NMFS, U.S.

West Coast

15 15 15 15 15

2.1.1.2 Increase

enforcement reduce

exploitation

1 Continuing NMFS, USCG,

DOS

Encourage Mexico

and Central

American

countries to

support this task

2.1 Protect & manage

populations in

marine habitat (cont.)

2.1.2 Determine

distribution,

abundance, status 

2.1.2.1 Determine

distribution,

abundance

posthatchlings,

juveniles, adults

1 10 years NMFS, FWS 50 50 50 50 50 Support and work

with Mexico and

Cenral American

countries to

implement this

task

2.1.2.2 Determine

adult migration

routes, internesting

habitats

2 3 years Support and work

with Mexico and

Cenral American

countries to

implement this

task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 49 The lead agency is listed first.

2.1 Protect & manage

populations in

marine habitat (cont.)

2.1.2 Determine

distribution,

abundance, status

(cont.) 

2.1.2.3 Determine

growth rates,

survivorship, age

sexual maturity

1 10 years NMFS, FWS 50 50 50 50 50 Encourage and

work with Mexico

and Central

American

countries to

implement this

task

2.1.2.4 Identify

current threats adults,

juveniles on foraging

grounds

1 Continuing Encourage and

work with Mexico

and Central

American

countries to

implement this

task

2.1 Protect & manage

populations in

marine habitat

(cont.)

2.1.3 Reduce effects

of entanglement &

ingestion marine

debris

2.1.3.1 Evaluate

extent ingestion of

persistent debris

2 5 years NMFS, EPA, 50 50 50 50 50

2.1.3.2 Evaluate

effects ingestion

persistent debris

2 3 years NMFS, FWS 100 100 100

2.1.3.3 Reduce,

eliminate persistent

debris

2 Continuing NMFS, EPA,

USCG

Encourage Mexico

and Central

American

countries to

support this task
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 50 The lead agency is listed first.

2.1 Protect & manage

populations in

marine habitat

(cont.)

2.1.4 Monitor, reduce

incidental mortality in

commercial,

recreational fisheries

1 Continuing NMFS, U.S.

West Coast,

Hawaii,

American

Samoa, Guam,

Palau, CNMI,

RMI, FSM,

Unincorp.

Territories

20 20 20 20 20

2.1.5 Eliminate

harassment of turtles

at sea

2 NA

2.1.6 Study the impact

of diseases on turtles

3 3 years NMFS, U.S.

West Coast,

Hawaii,

American

Samoa, Guam,

Palau, CNMI,

RMI, FSM,

Unincorp.

Territories, FWS

(as appropriate to

beach habitat)

40 40 40

2.1.7 Maintain

carcass stranding

network

2 Continuing NMFS, FWS 5 5 5 5 5 All sea turtle

species
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 51 The lead agency is listed first.

2.1 Protect & manage

populations in

marine habitat

(cont.)

2.1.8 Centralize

tagging program and

tag-series records

2 Continuing NMFS, FWS 60 60 60 60 60 Encourage Mexico

& Central

American

countries to

participate. All

sea turtle species

included.

2.2 Protect & manage

marine habitat

2.2.1 Identify

important habitat

1 10 years NMFS, U.S.

West Coast,

Hawaii,

American

Samoa, Guam,

Palau, CNMI,

RMI, FSM,

Unincorp.

Territories

Coordinate with

Tasks 2.1.2.1. &

2.1.2.2

2.2.2 Ensure longterm protection

1 Continuing Encourage Mexico

and Central

American

countries to

participate. 

2.2.3 Identify other

threats, take action

2 Continuing NMFS, EPA,

USCG

Encourage Mexico

and Central

American

countries to

participate. All

sea turtle species

3 Ensure proper care

in captivity

3.1 Develop captive

standards

3 2 year NMFS, FWS 35 15
IMPLEMENTATION SCHEDULE/U.S. PACIFIC

Olive Ridley (Lepidocheyls olivacea)

General Task

Categories

Plan Task PriorityA Task

Duration

Agencies

ResponsibleB

Current

Estimated Fiscal Year Costs $K

 

 FY2 FY3 FY4 FY5

Comments/

Notes

A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 52 The lead agency is listed first.

3 Ensure proper care

in captivity (cont.)

3.2 Catalog captive

turtles for research,

education

3 2 year NMFS, FWS 10 10

3.3 Designate rehab

facilities

3 1 year 25

4 International

cooperation

4.1 Support 

agreements, conventions, protect in

foreign water

1 Continuing FWS, NMFS,

DOS, DOI, DOC

100 100 100 100 100 Includes all turtle

species and tasks

5.2, 5.3. (1 FTE

and travel)

4.2 CITES

membership,

compliance

1 Continuing

4.3 Develop new

agreements to protect

in foreign waters

1 Continuing NMFS, DOS, 

DOI, DOC

4.4 Display

information at airports

2 5 years NMFS, FWS,

U.S.West Coast 

Hawaii,

American

Samoa, Guam,

Palau, CNMI,

RMI, FSM,

Unincorp.

Territories

15 15 15 15 15 Includes all sea

turtle species
A

 ( ) parentheses denote that this task does not necessarily apply to U.S. jurisdiction, but that the task must be addressed if the U.S. populations are to be

restored. Such tasks may require U.S. resource agencies to support recovery tasks in other political jurisdictions.

B 53 The lead agency is listed first.