Maria A. Marcovaldi

Tamar · Conservation and Reaserch

Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns through satellite telemetry, and isotopic niche...

Knowledge of life history parameters is essential for the effective management of species of conservation concern. For migratory marine vertebrates such as hawksbill sea turtles Eretmochelys imbricata, feeding aggregations are important developmental habitats, allowing the study of population dynamics. Here, we used data from a 31 yr mark-recapture...

The understanding of developmental and reproductive migrations of sea turtles is essential for effective protection and conservation efforts. Flipper tags remain a valuable method for detecting movements and migrations because they are cost-effective and conspicuous, allowing the detection of a tagged animal by any person worldwide. Here we report...

Somatic growth dynamics are an integrated response to environmental conditions. Hawksbill sea turtles (Eretmochelys imbricata) are long-lived, major consumers in coral reef habitats that move over broad geographic areas (hundreds to thousands of kilometers). We evaluated spatio-temporal effects on hawksbill growth dynamics over a 33-yr period and 2...

From northern Colombia to Tierra del Fuego, the South American continent stretches some 7,149 kilometers (4,443 miles) and is 4,353 km (2,705 mi) at its broadest. The fourth-largest continent, South America is number one in biodiversity. It is home to the world’s largest rainforest wilderness and river system (the Amazon) and to the world’s largest...

Genetic markers are often used to designate population units for management and conservation, but widespread sharing of mitochondrial DNA control-region haplotypes defined from short (<500 base-pair [bp]) sequences often limits inferences of population connectivity in marine turtles. Haplotype CM-A8, defined from 490-bp sequences, dominated the hap...

In the 35 years since its inception, the Brazilian National Program for the Conservation of Marine Turtles (TAMAR) has had great success in protecting the five species of sea turtles that occur in Brazil. It has also contributed significantly to worldwide scientific data and knowledge about these species’ biology, such as life cycles and migration...

Sea turtle movements are influenced and driven by marine currents. Their occurrence is determined by prey availability and sea temperature, with an apparent spatial association with frontal systems. Caretta caretta movements in the Western South Atlantic present seasonal patterns according to variability of sea surface temperature (SST). We analyze...

For effective management of species of conservation concern, knowledge of life history parameters is essential. Here, we present the results of one of the longest ongoing capture-mark-recapture studies of juvenile green turtles (Chelonia mydas) worldwide. From 1988 to 2013, 1,279 individual turtles were tagged in Fernando de Noronha, Brazil (3°51′S...

Climate change poses a unique threat to species with temperature dependent sex determination (TSD), such as marine turtles, where increases in temperature can result in extreme sex ratio biases. Knowledge of the primary sex ratio of populations with TSD is key for providing a baseline to inform management strategies and to accurately predict how fu...

Understanding the connections between sea turtle populations is fundamental for their effective conservation. Brazil hosts important hawksbill feeding areas, but few studies have focused on how they connect with nesting populations in the Atlantic. Here, we (1) characterized mitochondrial DNA control region haplotypes of immature hawksbills feeding...

Hybridization between hawksbill (Eretmochelys imbricata) and loggerhead (Caretta caretta) breeding groups is unusually common in Bahia state, Brazil. Such hybridization is possible because hawksbill and loggerhead nesting activities overlap temporally and spatially along the coast of this state. Nevertheless, the destinations of their offspring are...

Hybridization between hawksbill ( Eretmochelys imbricata ) and loggerhead ( Caretta caretta ) breeding groups is unusually common in Bahia state, Brazil. Such hybridization is possible because hawksbill and loggerhead nesting activities overlap temporally and spatially along the coast of this state. Nevertheless, the destinations of their offspring...

Hybridization between hawksbill ( Eretmochelys imbricata ) and loggerhead ( Caretta caretta ) breeding groups is unusually common in Bahia state, Brazil. Such hybridization is possible because hawksbill and loggerhead nesting activities overlap temporally and spatially along the coast of this state. Nevertheless, the destinations of their offspring...

In this paper, information is presented on green turtle (Chelonia mydas) nesting on Atol das Rocas (Rocas Atoll), north-eastern Brazil. The temporal distribution of nesting events per season, annual number of nests, carapace length of nesting females, clutch size, hatching success, incubation period, internesting interval, clutch frequency, observe...

Characterizing the behaviors of sea turtles and identifying high-use areas as they vary in time and space is important for conservation planning, particularly when turtles overlap with fisheries that may unintentionally harm them. Between July 2006 and March 2010, 27 satellite transmitters were deployed at sea on juvenile loggerheads Caretta carett...

Current understanding of spatial ecology is insufficient in many threatened marine species, failing to provide a solid basis for conservation and management. To address this issue for globally endangered green turtles, we investigated their population distribution by sequencing a mitochondrial control region segment from the Rocas Atoll courtship a...

Data on hawksbill Eretmochelys imbricata migratory patterns are virtually unknown for nesting populations in the South Atlantic Ocean. The most significant nesting ground for hawksbills in the South Atlantic is located in Brazil, specifically in the northern state of Bahia. From February to March 2005, 15 adult female hawksbills were equipped with...

Categories in which RMUs for each species occurred (including critical data needs RMUs). Categories: HR-HT = High risk-High threats; HR-LT = High risk-Low threats; LR-LT = Low risk-Low threats; LR-HT = Low risk-High threats. (DOCX)

Paired risk and threats scores for RMUs of each marine turtle species. (A) loggerheads (Caretta caretta), (B) green turtles (Chelonia mydas), (C) leatherbacks (Dermochelys coriacea, (D) hawskbills (Eretmochelys imbricata), (E) olive ridleys (Lepidochelys olivacea), (F) Kemp's ridleys (Lepidochelys kempii) and flatbacks (Natator depressus). Vertical...

Scoring system for population size criterion in risk matrix. Numbers are average annual nesting females for the most recent survey data available. (DOCX)

List of Regional Management Unit (RMU) codes used in Fig. 1. Species: Caretta caretta, loggerhead; Chelonia mydas, green turtle; Dermochelys coriacea, leatherback; Eretmochelys imbricata, hawksbill; Lepidochelys kempii, Kemp's ridley; Lepidochelys olivacea, olive ridley; Natator depressus, flatback. (DOCX)

Bibliography of literature used to score risk and threats criteria. (PDF)

Areas of Competence for Regional Fishery Bodies (RFB) with a management mandate. RFB acronyms: CCAMLR: Commission on the Conservation of Antarctic Marine Living Resources; CCBSP: Convention on the Conservation and Management of Pollock Resources in the Central Bering Sea; CCSBT: Commission for the Conservation of Southern Bluefin Tuna; GFCM: Genera...

Complete dataset used to score all criteria in Risk and Threats matrices, as well as data uncertainty scores. (XLS)

Complete list of SWOT – The State of the World's Sea Turtles data providers. (XLS)

Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widel...

Apresentação e justificativa de categorização O estado de conservação da tartaruga marinha Chelonia mydas (Linnaeus, 1758) (Cheloniidae) foi avaliado de acordo com os critérios da IUCN (2001), com base nos dados disponíveis até 2009. Síntese do processo de avaliação das tartarugas marinhas pode ser encontrada em Peres et al., neste número. A catego...

Apresentação e justificativa de categorização O estado de conservação da tartaruga marinha Lepidochelys olivacea (Eschscholtz, 1829) (Cheloniidae) foi avaliado de acordo com os critérios da IUCN (2001), com base nos dados disponíveis até 2009. Síntese do processo de avaliação das tartarugas marinhas pode ser encontrada em Peres et al., neste número...

Summary of Regional Management Units (RMUs) for marine turtles worldwide, including number of nesting sites and genetic stocks contained within each RMU. (DOC)

Metadata associated with each layer synthesized to generate Regional Management Units. (XLS)

Complete list of SWOT – The State of the World's Sea Turtles data providers. (XLS)

Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. There...

We studied inter- and postnesting movements in the major loggerhead Caretta caretta nesting population in Brazil. Ten breeding females were satellite-tracked from nesting grounds in the state of Bahia, northeastern Brazil, for up to 1284 d. Eight females stayed in the nesting area after deployment, showing fidelity between internesting home ranges...

We present long-term data for hawksbill (Eretmochelys imbricata) nesting in the 2 main rookeries in Brazil: 1) northern Bahia and Sergipe, where the estimated number of nests laid each year increased from 199 in the 1991–1992 nesting season to 1345 in the 2005–2006 season and 2) Rio Grande do Norte, where the estimated number of nests laid in the 2...

The loggerhead turtle Caretta caretta is one of the large and long-lived species that comprise the charismatic marine megafauna. The loggerhead is considered endangered, especially in the Pacific Ocean, where there have been substantial declines in all the major nesting populations. On the other hand, some loggerhead nesting populations in the nort...

Testing theories of dispersal is challenging in highly migratory species. In sea turtles, population size, geographic distance, natal homing, and ocean currents are hypothesized to affect dispersal. Little is known, however, about these mechanisms in sea turtles foraging along the South American coast. Green sea turtles feeding at Ubatuba (UB, n =...

Mitochondrial DNA (mtDNA) sequences were determined for 168 green turtles (Chelonia mydas) nesting at the 3 known rookeries in Brazil: Trindade (n = 99), Atol das Rocas (n = 37), and Fernando de Noronha (n = 16). In addition, 32 green turtles were sampled on foraging grounds at Atol das Rocas and Fernando de Noronha. Significant genetic structure e...

The Brazilian Sea Turtle Conservation Programme (TAMAR) was established in 1980 to protect sea turtles in Brazil and to re-establish their natural life cycle, which had been disrupted by humans. The programme is based on grassroots involvement by the coastal communities, and provides jobs and generates alternative sources of income. Within this fra...

Like all other species of sea turtle, the hawksbill turtle ( Eretmochelys imbricata) exhibits temperature- dependent sexual differentiation, with high incubation temperatures producing females and low temperatures producing males. Relatively little is known about the sex ratios of hatchlings produced by nesting populations of hawksbill turtles. Her...

Projeto TAMAR-IBAMA, jointly administered by the Government of Brazil and the non-governmental organization Fundação Pró-TAMAR, has established 18 conservation stations which cover 1100 km of the Brazilian mainland coast (in the states of São Paulo, Rio de Janeiro, Espı́rito Santo, Bahia, Sergipe, and Ceará). In the oceanic islands of Fernando de N...

The Brazilian Sea Turtle Conservation Programme (TAMAR) was established in 1980 to protect sea turtles in Brazil and to re-establish their natural life cycle, which had been disrupted by humans. The programme is based on grassroots involvement by the coastal communities, and provides jobs and generates alternative sources of income. Within this fra...

Chelon;(ln C01/sen'm;on (lnd Hiolo.I,'''Y. 1999.3(2):]01-307 2Rua Jacupiran1:a 57, Sao Paulo. sao Paulo. 01440-050, Brazil ABSTRA(.'T.-In Brazil, the primary nesting area for hawksbill turtles (Eretmochelys imbricata) is the northern part of the coast of Bahia State. The Brazilian Sea Turtle Conservation Program (TAMAR-IBAMA) has five research and...

A method of estimating natural sex ratios of hatchlings of species with temperature-dependent sexual differentiation from data on incubation durations is described. The method was applied to loggerhead turtles (Caretta caretta) nesting in Brazil. Data on incubation durations were collected from 11 nesting beaches monitored for up to six seasons. It...

1.1. An intermediate morphotype between Eretmochelys imbricata and Caretta caretta was studied in Praia do Forte, Bahia, Brazil.2.2. Three enzymatic systems were successfully analyzed: SOD, lactate dehydrogenase (LDH) and esterase (EST). Isoelectric focusing of total soluble proteins of muscle and transferrin were shown.3.3. Esterase exhibited nine...