RESUMEN
Small populations are often exposed to high inbreeding and mutational load that can increase the risk of extinction. The Sumatran rhinoceros was widespread in Southeast Asia, but is now restricted to small and isolated populations on Sumatra and Borneo, and most likely extinct on the Malay Peninsula. Here, we analyse 5 historical and 16 modern genomes from these populations to investigate the genomic consequences of the recent decline, such as increased inbreeding and mutational load. We find that the Malay Peninsula population experienced increased inbreeding shortly before extirpation, which possibly was accompanied by purging. The populations on Sumatra and Borneo instead show low inbreeding, but high mutational load. The currently small population sizes may thus in the near future lead to inbreeding depression. Moreover, we find little evidence for differences in local adaptation among populations, suggesting that future inbreeding depression could potentially be mitigated by assisted gene flow among populations.
Asunto(s)
Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Perisodáctilos/genética , Animales , Borneo , Especies en Peligro de Extinción/historia , Femenino , Flujo Génico , Variación Genética , Genoma , Historia del Siglo XXI , Historia Antigua , Endogamia , Indonesia , Mutación con Pérdida de Función , Masculino , Mutación , Densidad de Población , Selección GenéticaRESUMEN
The Mediterranean monk seal (Monachus monachus) is a flagship species for marine conservation, but important aspects of its life history remain unknown. Concerns over imminent extinction motivated a nuclear DNA study of the species in its largest continuous subpopulation in the eastern Mediterranean Sea. Despite recent evidence of partial subpopulation recovery, we demonstrate that there is no reason for complacency, as the species still shares several traits that are characteristic of a critically endangered species: Mediterranean monk seals in the eastern Mediterranean survive in three isolated and genetically depauperate population clusters, with small effective population sizes and high levels of inbreeding. Our results indicated male philopatry over short distances, which is unexpected for a polygynous mammal. Such a pattern may be explained by the species' unique breeding behavior, in which males defend aquatic territories near breeding sites, while females are often forced to search for new pupping areas. Immediate action is necessary to reverse the downward spiral of population decline, inbreeding accumulation and loss of genetic diversity. We propose concrete conservation measures for the Mediterranean monk seal focusing on reducing anthropogenic threats, increasing the population size and genetic diversity, and thus improving the long-term prospects of survival.
Asunto(s)
Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción , Phocidae , Distribución Animal/fisiología , Animales , Caniformia/clasificación , Conservación de los Recursos Naturales/historia , ADN Mitocondrial/análisis , Demografía , Ecosistema , Especies en Peligro de Extinción/historia , Pruebas Genéticas/veterinaria , Variación Genética/fisiología , Grecia/epidemiología , Historia del Siglo XX , Mar Mediterráneo , Densidad de Población , Dinámica Poblacional/historia , Phocidae/genéticaRESUMEN
Carcharhinus obsolerus is described based on three specimens from Borneo, Thailand and Vietnam in the Western Central Pacific. It belongs to the porosus subgroup which is characterised by having the second dorsal-fin insertion opposite the anal-fin midbase. It most closely resembles C. borneensis but differs in tooth morphology and counts and a number of morphological characters, including lack of enlarged hyomandibular pores which are diagnostic of C. borneensis. The historic range of C. obsolerus sp. nov. is under intense fishing pressure and this species has not been recorded anywhere in over 80 years. There is an urgent need to assess its extinction risk status for the IUCN Red List of Threatened Species. With so few known records, there is a possibility that Carcharhinus obsolerus sp. nov. has been lost from the marine environment before any understanding could be gained of its full historic distribution, biology, ecosystem role, and importance in local fisheries.
Asunto(s)
Especies en Peligro de Extinción , Tiburones/anatomía & histología , Tiburones/clasificación , Animales , Borneo , Especies en Peligro de Extinción/historia , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Maxilares/anatomía & histología , Masculino , Océano Pacífico , Especificidad de la Especie , Tailandia , Diente/anatomía & histología , VietnamRESUMEN
Pirá, Conorhynchos conirostris (Valenciennes, 1840), a large migratory catfish endemic to the São Francisco River (SFR), is listed as threatened in the red lists of both Brazil and the state of Minas Gerais. Although fishing for pirá has been prohibited, it is still an important fishery resource, particularly in the middle SFR. We used historical and current occurrence and abundance data regarding pirá to determine if it meets the IUCN criteria of a threatened species. Pirá occurs in the main course of the SFR as well as in its major tributaries. Unlike the most well-known migratory fishes of the SFR, pirá does not use floodplain lakes as nurseries. In the first half of the 20th century, pirá occurred from the upper to the lower SFR. Currently, it is most abundant in the middle SFR, and is rare in the upper SFR and even rarer in the sub-middle SFR. Pirá has not been captured in the lower SFR since around the mid-1980's. Despite the reduction in its geographic distribution, we did not find evidence to justify considering pirá as threatened. Thus, we recommend that it be removed from the red lists of Brazil and the state of Minas Gerais.(AU)
Pirá, Conorhynchos conirostris (Valenciennes, 1840), um grande siluriforme migrador endêmico do rio São Francisco (RSF), está incluído como ameaçado nas listas vermelhas do Brasil e do estado de Minas Gerais. Embora sua pesca esteja proibida, ele ainda é recurso pesqueiro importante, particularmente no médio RSF. Utilizamos dados históricos e atuais de ocorrência e abundância do pirá para determinar se ele atende aos critérios da UICN para ser classificado como ameaçado. Pirá ocorre na calha do RSF, bem como em seus principais afluentes. Ao contrário dos peixes migradores mais conhecidos do RSF, ele não usa lagoas das várzeas como berçários. Na primeira metade do século 20, pirá costumava ocorrer do alto ao baixo RSF. Atualmente, ele é mais abundante no médio RSF. A espécie é rara no alto RSF e parece ainda mais rara no sub-médio RSF. O pirá não é capturado no baixo RSF desde cerca da metade da década de 1980. Apesar da redução na distribuição geográfica, não encontramos evidências para classificar o pirá como espécie ameaçada e, portanto, recomendamos que ele seja removido das listas vermelhas do Brasil e do estado de Minas Gerais.(AU)
Asunto(s)
Animales , Bagres/clasificación , Conservación de los Recursos Naturales , Especies en Peligro de Extinción/historia , Especies en Peligro de Extinción/tendenciasRESUMEN
Chinese populations of the endangered Siberian salamander Ranodon sibiricus are reported to have diverged only about 120 years ago, and to have the lowest genetic diversity of any amphibian. However, these conclusions require verification, as the main range of the species is in Kazakhstan. Moreover, the generation time used for estimating divergence time has a weak ground. In order to clarify these problems, we investigated the molecular phylogenetic relationship and historical demography of the species covering its whole distribution range using the mitochondrial DNA region reported for Chinese population (1072 bp sequences of the control region), while conducting skeletochronological analysis to estimate accurate generation time. As a result, the range expansion was estimated at 88,000-50,000 YA, based on the generation time of 6-10 years. Degree of intraspecific genetic differentiation is actually very small, but, as a single species, is not so small as had been reported for Chinese population alone.
Asunto(s)
Especies en Peligro de Extinción/historia , Urodelos/clasificación , Urodelos/fisiología , Distribución Animal , Animales , Asia , Variación Genética , Haplotipos , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Dinámica Poblacional , Urodelos/genéticaRESUMEN
Batrachochytrium dendrobatidis (Bd), the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth's most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925-1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper) collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions are encountered in the future.
Asunto(s)
Anfibios/microbiología , Quitridiomicetos/aislamiento & purificación , Quitridiomicetos/patogenicidad , África Central , Animales , Biodiversidad , Quitridiomicetos/genética , ADN de Hongos/genética , ADN de Hongos/aislamiento & purificación , Dermatomicosis/historia , Dermatomicosis/microbiología , Dermatomicosis/veterinaria , Ecosistema , Especies en Peligro de Extinción/historia , Historia del Siglo XX , Historia del Siglo XXI , Reacción en Cadena de la Polimerasa , Piel/microbiología , Piel/patologíaRESUMEN
O Livro Vermelho é organizado a partir de uma Lista de Espécies Ameaçadas de Extinção e reúne várias informações científicas sobre os bichos, sobre as ameaças à sobrevivência deles, o motivo pelo qual correm risco de extinção, a categoria de ameaça de cada um, ações que podem ser feitas para deixar de serem espécies ameaçadas de extinção, nome de pesquisadores e instituições que se dedicam a pesquisar a fauna. Tudo isso em um só livro! O objetivo do Livro Vermelho é informar e alertar a sociedade sobre as espécies que correm risco de desaparecer na natureza.
Asunto(s)
Animales , Especies en Peligro de Extinción/historia , Fauna , Publicaciones de Divulgación Científica , Educación en Salud AmbientalRESUMEN
Cystoseira amentacea is a Mediterranean endemic alga thriving on very shallow rocky substrates. It has been considered as a threatened species, having experienced a steady decline and is therefore protected by international conventions. The historical distribution of the species has been assessed along the French Mediterranean coast, on the basis of 467 articles and herbarium vouchers. We have produced an accurate map of its current distribution and abundance along 1832 km of coastline, through in situ surveys. C. amentacea was observed along 1125 km of shoreline, including 33% of almost continuous or continuous belt. In most of its range, there is no evidence of loss, except in 4 areas of Provence, French Riviera and Corsica. A significant relation was found between the absence or low abundance of C. amentacea and the vicinity of ports and large sewage outfalls. The status of conservation of the species should therefore be reassessed.
Asunto(s)
Especies en Peligro de Extinción/historia , Phaeophyceae , Animales , Acuicultura , Francia , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Mar Mediterráneo , Aguas del Alcantarillado/efectos adversos , Contaminación del Agua/efectos adversosRESUMEN
Edward Blyth was born on 23 December 1810. When he was ayoung man he took an interest with the zoology which became his life's passion. As a young naturalist he was a conscientious observer of the nature and a man gifted with a superb memory. Unfortunately his career was not successful in London because of the conflict with the younger of the Gray brothers. Facing the prospect of no employment in The British Museum, Blyth decided to leave England for Calcutta where he was offered a post of a museum curator. The English naturalist spent in India the years from 1841 to 1862. During that time he greatly enriched the zoological collection of the museum and consequently the place had much more visitors. Regarding his private life he got married in 1854 to Elisabeth Mary Turner Hodges. Undoubtedly the next four year were the happiest in Blyth's life. After his wife's death Blyth's health condition deteriorated. The ongoing conflicts he kept having while the first stay in India and constant struggle to improve his financial status made him decide to return to England. Blyth left India in 1862. After coming back to his homeland he continued the naturalistic passions. Nevertheless Blyth was constantly troubled by the financial problems. Also, his health, both mental and physical, systematically deteriorated. Finally the death came on 27 December 1873, in London. Blyth tried in vain to gain the recognition and join the scientific establishment of the 19th century England. Constant lack of satisfactory income and often problems with health prevented the ornithologist to be fully devote to his passion. The aim of this article is to highlight some of the most important and interesting events of Blyth's life. Moreover, another objective is to popularise Blyth and his work since he was one of the greatest naturalists of that time.
Asunto(s)
Especies en Peligro de Extinción/historia , Museos/historia , Zoología/historia , Animales , Animales de Zoológico , Inglaterra , Historia del Siglo XIX , Humanos , India , MasculinoRESUMEN
This paper explores the relations between economy and ecology in the last quarter of the 20th century with the example of biodiversity. From its definition in the 1980s, the concept of biodiversity responded not only to conservational concerns but also to hopes and demands of economic profitability. The paper argues that archival systems of inventorying and surveying nature, the biodiversity database and the biodiversity portfolio, changed the view on nature from a resource to an investment. The paper studies the alliances of ecologists and environmental economists in managing nature according to economic principles of successful asset management, "diversification", with the aim to distribute risk, minimize ecological loss and maximize overall ecosystem performance. Finally, the paper discusses the assumptions and the consequences of transferring principles from financial risk management to landscape management. How has the substitution of the existential values of nature by shareholder value affected the relations between ecology, environment, and ecosystem conservation? Who gains and who looses in exchanging natural capital and financial capital, yields, and profits?
Asunto(s)
Biodiversidad , Comercio/historia , Comercio/tendencias , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/tendencias , Ecología/historia , Ecología/tendencias , Especies en Peligro de Extinción/historia , Especies en Peligro de Extinción/tendencias , Inversiones en Salud/historia , Inversiones en Salud/tendencias , Naturaleza , Animales , Comercio/economía , Conservación de los Recursos Naturales/economía , Especies en Peligro de Extinción/economía , Predicción , Historia del Siglo XX , Humanos , Inversiones en Salud/economíaRESUMEN
Using a recent environmental controversy on the U.S. east coast over the conservation of red knots (Calidris canutus rufa) as a lens, I present a history of North American efforts to understand and conserve migratory shorebirds. Focusing on a few signal pieces of American legislation and their associated bureaucracies, I show the ways in which migratory wildlife have been thoroughly enrolled in efforts to quantify and protect their populations. Interactions between wildlife biologists and endangered species have been described by some scholars as "domestication"-a level of surveillance and intervention into nonhuman nature that constitutes a form of dependence. I pause to reflect on this historical trajectory, pointing out the breaks and continuities with older forms of natural history. Using the oft-mobilized Foucauldian metaphor of the panopticon as a foil, I question the utility and ethics of too-easily declaring "domesticated" wildlife an act of "biopower." Instead, I argue that Jacob von Uexküll's "umwelt" from early ecology and ethology, and more contemporary Science and Technology Studies (STS) analyses emphasizing multiple ontologies, offer more illuminating accounts of endangered species science. Neither science, conservation, nor history are well-served by the conflation of wildlife "surveillance" with the language of Foucauldian discipline.
Asunto(s)
Aves , Conservación de los Recursos Naturales/historia , Ecología/historia , Ecosistema , Especies en Peligro de Extinción/historia , Animales , Etología/historia , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Historia Natural/historia , Ciencia/historia , Estados UnidosRESUMEN
Batrachochytrium dendrobatidis is considered a main driver of the worldwide declines and extinctions of amphibian populations. Nonetheless, fundamental questions about its epidemiology, including whether it acts mainly as a "lone killer" or in conjunction with other factors, remain largely open. In this paper we analysed contemporary and historical samples of the endangered Apennine yellow-bellied toad (Bombina pachypus) along the Italian peninsula, in order to assess the presence of the pathogen and its spreading dynamics. Once common throughout its range, B. pachypus started to decline after the mid-1990s in the northern and central regions, whereas no declines have been observed so far in the southern region. We show that Batrachochytrium dendrobatidis is currently widespread along the entire peninsula, and that this was already so at least as early as the late 1970s, that is, well before the beginning of the observed declines. This temporal mismatch between pathogen occurrence and host decline, as well as the spatial pattern of the declines, suggests that the pathogen has not acted as a "lone killer", but in conjunction with other factors. Among the potentially interacting factors, we identified two as the most probable, genetic diversity of host populations and recent climate changes. We discuss the plausibility of this scenario and its implications on the conservation of B. pachypus populations.
Asunto(s)
Anuros/microbiología , Quitridiomicetos/fisiología , Especies en Peligro de Extinción/historia , Animales , Geografía , Historia del Siglo XX , Italia , Reacción en Cadena de la PolimerasaRESUMEN
Rather than exploring how indigenous people have been alienated from resources by environmental policies, this paper explores how indigenous peoples have worked with environmental organizations to use the broad protections provided by environmental laws to protect cultural resources. The Eastern Band of Cherokee Indians, along with other concerned groups, partnered with environmentalists in opposing the destruction of the endangered snail darter's critical habitat by the Tennessee Valley Authority's Tellico Dam. The dam had been opposed by a shifting alliance of Cherokees, local farmers, trout fisherman, and environmentalists since it was announced in 1963. A previous lawsuit by this coalition delayed the project from 1972 to 1974 under the National Environmental Policy Act. The Endangered Species Act provided this coalition with a powerful tool for opposing the destruction of burial grounds and sacred village sites throughout the lower Little Tennessee River valley. The coalition of environmental organizations, Cherokees, and others was ultimately unsuccessful in stopping the dam from being built, but was successful in establishing a strict precedent for the enforcement of the Endangered Species Act. The lawsuit also created a space for the Eastern Band to negotiate for the return of Cherokee remains and halt the removal of any additional burials. In this situation, the strategic support of environmental regulation enabled the Eastern Band to exert some degree of control over the fate of cultural resources in the valley, and also demonstrates the significant role American Indian peoples played in one of the seminal events of the environmental movement during the 1970s.
Asunto(s)
Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción/historia , Política Ambiental/legislación & jurisprudencia , Percas/fisiología , Animales , Conservación de los Recursos Naturales/historia , Política Ambiental/historia , Historia del Siglo XX , Humanos , Indígenas Norteamericanos , TennesseeRESUMEN
A new international initiative for plant conservation was first called for as a resolution of the International Botanical Congress in 1999. The natural home for such an initiative was considered to be the Convention on Biological Diversity (CBD), and the Conference of the Parties (COP) to the CBD agreed to consider a Global Strategy for Plant Conservation (GSPC) at its 5th meeting in 2000. It was proposed that the GSPC could provide an innovative model approach for target setting within the CBD and, prior to COP5, a series of inter-sessional papers on proposed targets and their justification were developed by plant conservation experts. Key factors that ensured the adoption of the GSPC by the CBD in 2002 included: (1) ensuring that prior to and during COP5, key Parties in each region were supportive of the Strategy; (2) setting targets at the global level and not attempting to impose these nationally; and (3) the offer by Botanic Gardens Conservation International (BGCI) to support a GSPC position in the CBD Secretariat for 3 years, which provided a clear indication of the support for the GSPC from non-governmental organizations (NGO).
Asunto(s)
Biodiversidad , Botánica , Conservación de los Recursos Naturales , Ecosistema , Especies en Peligro de Extinción , Internacionalidad , Botánica/economía , Botánica/educación , Botánica/historia , Botánica/legislación & jurisprudencia , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/legislación & jurisprudencia , Especies en Peligro de Extinción/economía , Especies en Peligro de Extinción/historia , Especies en Peligro de Extinción/legislación & jurisprudencia , Jardinería/economía , Jardinería/educación , Jardinería/historia , Jardinería/legislación & jurisprudencia , Historia del Siglo XX , Historia del Siglo XXI , Internacionalidad/historia , Internacionalidad/legislación & jurisprudencia , Organizaciones/economía , Organizaciones/historia , Organizaciones/legislación & jurisprudencia , Salud Pública/economía , Salud Pública/educación , Salud Pública/historia , Investigación/economía , Investigación/educación , Investigación/historiaRESUMEN
China is one of the richest countries for plant diversity with approximately 33 000 vascular plant species, ranking second in the world. However, the plant diversity in China is increasingly threatened, with an estimated 40005000 plant species being threatened or on the verge of extinction, making China, proportionally, one of the highest priorities for global plant biodiversity conservation. Coming in the face of the current ecological crisis, it is timely that China has launched China's Strategy for Plant Conservation (CSPC). China has increasingly recognized the importance of plant diversity in efforts to conserve and sustainably use its plant diversity. More than 3000 nature reserves have been established, covering approximately 16% of the land surface of China. These natural reserves play important roles in plant conservation, covering more than 85% of types of terrestrial natural ecosystems, 40% of types of natural wetlands, 20% of native forests and 65% of natural communities of vascular plants. Meanwhile, the flora conserved in botanical gardens is also extensive. A recent survey shows that the 10 largest botanical gardens have living collections of 43 502 taxa, with a total of 24 667 species in ex situ conservation. These provide an important reserve of plant resources for sustainable economic and social development in China. Plant diversity is the basis for bioresources and sustainable utilization. The 21st century is predicted to be an era of bio-economy driven by advances of bioscience and biotechnology. Bio-economy may become the fourth economy form after agricultural, industrial, and information and information technology economies, having far-reaching impacts on sustainable development in agriculture, forestry, environmental protection, light industry, food supply and health care and other micro-economy aspects. Thus, a strategic and forward vision for conservation of plant diversity and sustainable use of plant resources in the 21st century is of far-reaching significance for sustainable development of Chinese economy and society.
Asunto(s)
Biodiversidad , Biotecnología , Conservación de los Recursos Naturales , Economía , Ecosistema , Agricultura/economía , Agricultura/educación , Agricultura/historia , Biotecnología/economía , Biotecnología/educación , Biotecnología/historia , China/etnología , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/legislación & jurisprudencia , Economía/historia , Economía/legislación & jurisprudencia , Especies en Peligro de Extinción/historia , Agricultura Forestal/economía , Agricultura Forestal/educación , Agricultura Forestal/historia , Agricultura Forestal/legislación & jurisprudencia , Historia del Siglo XX , Historia del Siglo XXI , PlantasRESUMEN
Mexico as a megadiverse country houses between 6 and 8% of the world's flora. However, the Mexican flora is facing challenges, including the presence of at least 981 threatened plant species and 618 exotic plant species, habitat loss, pollution, overexploitation of natural resources and the adverse effects of climate change, which are compromising its conservation and sustainable use. Mexico has been actively involved in the development and update of the Global Strategy for Plant Conservation (GSPC) adopted by the Convention on Biological Diversity (CBD). As a party to CBD, Mexico has established a Coordinating Committee for the Mexican Strategy for Plant Conservation (MSPC), which has adapted the GSPC to fit national needs and drafted a number of projects, indicators, means of verification and actors to ensure that the MSPC, as a public policy tool, really drives conservation and sustainable use actions among all sectors and lasts beyond the current administration. An agenda is being developed with activities that include the following: approaching Congress, identifying the relevance of the MSPC in the National Development Plan and the Mexican Biodiversity Strategy, making use of current environmental policies and an aggressive awareness programme. The MSPC includes simultaneous programmes of technical and political work.
Asunto(s)
Contaminación del Aire , Biodiversidad , Conservación de los Recursos Naturales , Salud Pública , Política Pública , Contaminación del Aire/economía , Contaminación del Aire/historia , Contaminación del Aire/legislación & jurisprudencia , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/legislación & jurisprudencia , Especies en Peligro de Extinción/economía , Especies en Peligro de Extinción/historia , Especies en Peligro de Extinción/legislación & jurisprudencia , Gobierno/historia , Historia del Siglo XX , Historia del Siglo XXI , México/etnología , Plantas , Salud Pública/economía , Salud Pública/educación , Salud Pública/historia , Salud Pública/legislación & jurisprudencia , Política Pública/economía , Política Pública/historia , Política Pública/legislación & jurisprudenciaAsunto(s)
Biodiversidad , Botánica , Conservación de los Recursos Naturales , Ecosistema , Indígenas Norteamericanos , Dinámica Poblacional , Botánica/educación , Botánica/historia , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/historia , Especies en Peligro de Extinción/economía , Especies en Peligro de Extinción/historia , Geografía/educación , Geografía/historia , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Indígenas Norteamericanos/educación , Indígenas Norteamericanos/etnología , Indígenas Norteamericanos/historia , Indígenas Norteamericanos/legislación & jurisprudencia , Indígenas Norteamericanos/psicología , Dinámica Poblacional/historiaRESUMEN
Methylmercury cycling in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists concerning whether increases in anthropogenic emissions over time may have caused increased mercury bioaccumulation in the biota. To address this, we measured total mercury and, for a subset of samples, methylmercury (the bioaccumulated form of mercury) in museum feathers from an endangered seabird, the black-footed albatross (Phoebastria nigripes), spanning a 120-y period. We analyzed stable isotopes of nitrogen (δ(15)N) and carbon (δ(13)C) to control for temporal changes in trophic structure and diet. In post-1940 and -1990 feathers, we detected significantly higher mean methylmercury concentrations and higher proportions of samples exhibiting above deleterious threshold levels (â¼ 40,000 ng · g(-1)) of methylmercury relative to prior time points, suggesting that mercury toxicity may undermine reproductive effort in the species. We also found higher levels of (presumably curator-mediated) inorganic mercury in older specimens of albatross as well as two nonpelagic species lacking historical exposure to bioavailable mercury, patterns suggesting that studies on bioaccumulation should measure methylmercury rather than total mercury when using museum collections. δ(15)N contributed substantially to models explaining the observed methylmercury variation. After simultaneously controlling for significant trends in δ(13)C over time and δ(15)N with methylmercury exposure, year remained a significant independent covariate with feather methylmercury levels among the albatrosses. These data show that remote seabird colonies in the Pacific basin exhibit temporal changes in methylmercury levels consistent with historical global and recent regional increases in anthropogenic emissions.
Asunto(s)
Aves/metabolismo , Especies en Peligro de Extinción/historia , Monitoreo del Ambiente/estadística & datos numéricos , Contaminantes Ambientales/análisis , Contaminantes Ambientales/historia , Plumas/química , Compuestos de Metilmercurio/análisis , Animales , Isótopos de Carbono/análisis , Monitoreo del Ambiente/historia , Monitoreo del Ambiente/métodos , Cromatografía de Gases y Espectrometría de Masas , Historia del Siglo XIX , Historia del Siglo XX , Museos , Isótopos de Nitrógeno/análisis , Océano Pacífico , Análisis de Regresión , Espectrofotometría AtómicaRESUMEN
Palaeontologists characterize mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval, as has happened only five times in the past 540 million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia. Here we review how differences between fossil and modern data and the addition of recently available palaeontological information influence our understanding of the current extinction crisis. Our results confirm that current extinction rates are higher than would be expected from the fossil record, highlighting the need for effective conservation measures.