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1.
Proc Natl Acad Sci U S A ; 118(23)2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34083434

RESUMO

Explaining why some species are widespread, while others are not, is fundamental to biogeography, ecology, and evolutionary biology. A unique way to study evolutionary and ecological mechanisms that either limit species' spread or facilitate range expansions is to conduct research on species that have restricted distributions. Nonindigenous species, particularly those that are highly invasive but have not yet spread beyond the introduced site, represent ideal systems to study range size changes. Here, we used species distribution modeling and genomic data to study the restricted range of a highly invasive Australian marine species, the ascidian Pyura praeputialis This species is an aggressive space occupier in its introduced range (Chile), where it has fundamentally altered the coastal community. We found high genomic diversity in Chile, indicating high adaptive potential. In addition, genomic data clearly showed that a single region from Australia was the only donor of genotypes to the introduced range. We identified over 3,500 km of suitable habitat adjacent to its current introduced range that has so far not been occupied, and importantly species distribution models were only accurate when genomic data were considered. Our results suggest that a slight change in currents, or a change in shipping routes, may lead to an expansion of the species' introduced range that will encompass a vast portion of the South American coast. Our study shows how the use of population genomics and species distribution modeling in combination can unravel mechanisms shaping range sizes and forecast future range shifts of invasive species.


Assuntos
Variação Genética , Genômica , Genótipo , Espécies Introduzidas , Urocordados/genética , Animais , Austrália , Chile
4.
Nature ; 580(7801): 39-51, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238939

RESUMO

Sustainable Development Goal 14 of the United Nations aims to "conserve and sustainably use the oceans, seas and marine resources for sustainable development". Achieving this goal will require rebuilding the marine life-support systems that deliver the many benefits that society receives from a healthy ocean. Here we document the recovery of marine populations, habitats and ecosystems following past conservation interventions. Recovery rates across studies suggest that substantial recovery of the abundance, structure and function of marine life could be achieved by 2050, if major pressures-including climate change-are mitigated. Rebuilding marine life represents a doable Grand Challenge for humanity, an ethical obligation and a smart economic objective to achieve a sustainable future.


Assuntos
Ecossistema , Espécies em Perigo de Extinção/estatística & dados numéricos , Recuperação e Remediação Ambiental/tendências , Biologia Marinha/tendências , Animais , Extinção Biológica , Peixes , Aquecimento Global/prevenção & controle , Atividades Humanas , Humanos
5.
Conserv Biol ; 32(3): 619-627, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29114934

RESUMO

Illegal fishing poses a major threat to conservation of marine resources worldwide. However, there is still limited empirical research that quantifies illegal catch levels. We used the randomized response technique to estimate the proportion of divers and the quantities of loco (Concholepas concholepas) they extracted illegally. Loco have been managed for the past 17 years through a territorial user rights for fisheries system (TURFs) in Chile. Illegal fishing of loco was widespread within the TURFs system. Official reported landings (i.e., legal landings) accounted for 14-30% of the total loco extraction. Our estimates suggest that ignoring the magnitude of illegal fishing and considering only official landing statistics may lead to false conclusions about the status and trends of a TURFs managed fishery. We found evidence of fisher associations authorizing their members to poach inside TURFs, highlighting the need to design TURFs systems so that government agencies and fishers' incentives and objectives align through continuous adaptation. Government support for enforcement is a key element for the TURFs system to secure the rights that are in place.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Animais , Chile , Motivação , Alimentos Marinhos
6.
Proc Natl Acad Sci U S A ; 114(24): 6167-6175, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28584096

RESUMO

Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Ecossistema , Adaptação Fisiológica , Animais , Organismos Aquáticos
7.
Ambio ; 46(6): 706-716, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28247340

RESUMO

Artisanal fishery activities support the livelihoods of millions of people worldwide, particularly in developing countries. Within these fisheries, distal global drivers can promote switching between alternative target resources. These drivers can promote the rapid development of new, unregulated and previously unexploited fisheries that pose a threat to the sustainability of ecosystems. In this paper, we describe a new artisanal shore gathering activity that targets a previously unexploited resource: the sandhopper (Orchestoidea tuberculata). The activity is driven by aquarium trade demand for food. We used mixed methods to describe the activity, assessed basic socio-economic incentives, and estimated Catches per Unit Effort. Results show that the sandhopper plays an important role for the livelihoods of shore gatherers engaged in the activity. Gatherers have adapted and developed two main extraction methods with different degrees of investment and extraction rates. Furthermore, gatherers have developed local knowledge regarding the ecology and management of the resource. Results show that economic incentives can motivate a rapid expansion of this unregulated activity. Future research gaps and management options to address the development of this fishery are discussed in light of these findings.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Animais , Chile , Ecologia , Ecossistema , Peixes
8.
Ambio ; 46(2): 184-189, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27530553

RESUMO

Biodiversity offsets are becoming increasingly common across a portfolio of settings: national policy, voluntary programs, international lending, and corporate business structures. Given the diversity of ecological, political, and socio-economic systems where offsets may be applied, place-based information is likely to be most useful in designing and implementing offset programs, along with guiding principles that assure best practice. We reviewed the research on biodiversity offsets to explore gaps and needs. While the peer-reviewed literature on offsets is growing rapidly, it is heavily dominated by ecological theory, wetland ecosystems, and U.S.-based research. Given that majority of offset policies and programs are occurring in middle- and low-income countries, the research gaps we identified present a number of risks. They also present an opportunity to create regionally based learning platforms focused on pilot projects and institutional capacity building. Scientific research should diversify, both topically and geographically, in order to support the successful design, implementation, and monitoring of biodiversity offset programs.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/legislação & jurisprudência
9.
Cuad. bioét ; 27(91): 403-413, sept.-dic. 2016.
Artigo em Inglês | IBECS | ID: ibc-159475

RESUMO

The paper centers on environmental practical ethic point of views according to a professional ecologist. Ecology and the science of Socio-ecology are defined. The framework of the Millennium Ecosystem Assessment initiative (MA 2003), including the use of ecosystems as the environmental unit of analysis, ecosystem services and human well-being as the center for assessment are discussed. Common-pool resources (CPR) and the allegory of the tragedy of the commons are used to illustrate main scientific and ethical environmental approaches, and above all to highlight the case of climate change, considering «air-atmosphere» as a CPR. The need to adopt practical personal environmental ethical positions is highlighted. Furthermore, on climate change, a discussion on the need to develop environmental and socio-ecological polycentric approaches: top-down and bottom-up, is included. An updated discussion on the concept of conservation, including main scientific and ethic points of view, is presented. Pope Francis’s Encyclical, Laudato Si’, is used to highlight environmental, socio-ecological and ethical aspects behind the comprehensive concept of Integral Ecology. The paper ends with a short synthesis on Earth modern unseen and astonishing environmental and socio-ecological rates of changes, and identifying the main barriers for personal environmental engagement. A call is done regarding the urgent need for socio-environmental ethic personal engagement and collective actions


El trabajo está centrado en torno a puntos de vista éticos ambientales prácticos de un ecólogo profesional. La Ecología y la ciencia de la Socio-ecología son definidas. El marco de referencia de la iniciativa Millennium Ecosystem Assessment (MA 2003), incluyendo a los ecosistemas como unidades de análisis ambiental, los servicios ecosistémicos y el bienestar humano, como el centro de las evaluaciones son discutidos. Los recursos de acceso común (RAC) y la alegoría de la tragedia de los comunes son usados para ilustrar las principales aproximaciones ambientales científicas y éticas, y en especial para destacar el caso del cambio climático, considerando al «aire-atmósfera» como un RAC. La necesidad de adoptar posiciones prácticas éticas ambientales es destacada. Además, en relación con el cambio climático, se presenta una discusión sobre la necesidad de desarrollar estrategias ambientales y socio-ambientales de tipo policéntricas: de arriba hacia abajo y de abajo hacia arriba. Adicionalmente, se entrega una discusión actualizada sobre el concepto de conservación, destacando las principales aristas científicas y éticas. La Encíclica del Papa Francisco, Laudato Si’, es usada para resaltar aspectos ambientales, socio-ecológicos y éticos contenidos en el concepto de Ecología Integral. El trabajo finaliza con una síntesis corta sobre las enormes y nunca antes experimentadas modernas tasas de modificaciones ambientales y socio-ecológicas en el planeta y con la identificación de las principales barreras que impiden una conexión y enganche verdadero y profundo de las personas con el socio-ambiente. Se realiza un llamado urgente en relación con la necesidad de sobrepasar dichas barreras y desarrollar acciones éticas ambientales tanto personales como colectivas


Assuntos
Humanos , Ecologia/ética , Ecologia Humana/ética , Mudança Climática , Preservação Biológica/ética , Conservação dos Recursos Naturais , Conservação dos Recursos Naturais , Estratégias de Saúde Nacionais
10.
Cuad Bioet ; 27(91): 403-414, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28092716

RESUMO

The paper centers on environmental practical ethic point of views according to a professional ecologist. Ecology and the science of Socio-ecology are defined. The framework of the Millennium Ecosystem Assessment initiative (MA 2003), including the use of ecosystems as the environmental unit of analysis, ecosystem services and human well-being as the center for assessment are discussed. Common-pool resources (CPR) and the allegory of the tragedy of the commons are used to illustrate main scientific and ethical environmental approaches, and above all to highlight the case of climate change, considering ″air-atmosphere″ as a CPR. The need to adopt practical personal environmental ethical positions is highlighted. Furthermore, on climate change, a discussion on the need to develop environmental and socio-ecological polycentric approaches: top-down and bottom-up, is included. An updated discussion on the concept of conservation, including main scientific and ethic points of view, is presented. Pope Francis's Encyclical, Laudato Si', is used to highlight environmental, socio-ecological and ethical aspects behind the comprehensive concept of Integral Ecology. The paper ends with a short synthesis on Earth modern unseen and astonishing environmental and socio-ecological rates of changes, and identifying the main barriers for personal environmental engagement. A call is done regarding the urgent need for socio-environmental ethic personal engagement and collective actions.


Assuntos
Conservação dos Recursos Naturais , Ecologia/ética , Ecossistema , Saúde Ambiental/ética , Mudança Climática , Humanos
11.
Acta bioeth ; 21(1): 65-71, jun. 2015.
Artigo em Espanhol | LILACS | ID: lil-749414

RESUMO

La tragedia de los recursos de uso común (sobreexplotación, contaminación) es una metáfora bien acuñada en la literatura. El aire es un recurso de uso común, sobre el que no existe propiedad privada. El problema del calentamiento global, derivado del exceso de gases de efecto invernadero (CO2, NO2, metano), generados por actividades humanas y el excesivo consumismo, y que se almacenan en la alta atmósfera causando cambios climáticos, es hoy una tragedia. Vivimos una nueva Era llamada del Antropoceno. Las soluciones monocéntricas globales a esta tragedia, de arriba hacia abajo -por ejemplo, Protocolo de Kyoto, de 1997- han fracasado. El artículo destaca la necesidad urgente de comenzar a usar soluciones estratégicas policéntricas -de abajo hacia arriba-, acciones individuales y colectivas, en conjunto con las globales, para enfrentar la tragedia. Ello debe basarse en la instalación masiva de una nueva ética ambiental responsable, basada, por ejemplo, en el principio ético de responsabilidad individual de Kutz. Para ello se necesita poner en acción una ciencia ambiental posmoderna, creíble, con una democratización del conocimiento, y alfabetizar a la sociedad en forma simple y directa sobre la información dura del cambio climático en todas sus dimensiones: negativas, positivas y de nuevas oportunidades. Los medios de comunicación social masivos pueden ser la clave para lograr este objetivo.


The tragedy of the commons (overexploitation, pollution) is a metaphor well anchored in the literature. The air is a common pool resource and private property does not exist. The global warming of the planet, caused by excess greenhouse gas emissions (CO2, NO2, methane), generated by human activities and consuming society, which are stored in the high atmosphere causing climatic changes, is today a tragedy. We live in a new Era, that of the Antrophocene. Monocentric solutions to this tragedy: topdown -for instance the Kyoto Protocol of 1997- have failed. The article highlights the urgent need to implement polycentric solutions to face the tragedy: bottomup, individual and collective actions in concurrence with topdown strategies. This needs to be based in the installation of a new environmental responsible ethic, for instance based in the individual responsible Kutz ethic principle. For this is needed to promote, as soon as possible, a postmodern environmental science, with credibility and a true democratization of knowledge. Moreover, there is a need for environmental alphabetization of our society based on hard knowledge about climatic changes and global warming, in all dimensions: negative, positive, new opportunities. The use of massive communication tools may be the key to achieve the goal.


A tragédia dos recursos de uso comum (superexploração, contaminação) é uma metáfora bem cunhada na literatura. O ar é um recurso de uso comum, sobre o qual não existe propriedade privada. O problema do aquecimento global derivado do excesso de gases de efeito estufa (CO2, NO2, metano), gerados por atividades humanas e o excessivo consumismo, que se armazenam na alta atmosfera causando mudanças climáticas, é hoje uma tragédia. Vivemos uma nova Era chamada de Antropoceno. As soluções monocêntricas globais a esta tragédia, de cima para baixo por exemplo, Protocolo de Kyoto de 1997 fracassaram. O artigo destaca a necessidade urgente de começar a usar soluções estratégicas policêntricas de baixo para cima , ações individuais e coletivas, em conjunto com as globais, para enfrentar a tragédia. Isso tem que basearse na instalação massiva de uma nova ética ambiental responsável por exemplo, baseada no princípio ético de responsabilidade individual de Kutz. Para isso se necessita por em acção uma ciência ambiental pósmoderna, crível, com uma democratização do conhecimento, e alfabetizar a sociedade de forma simples e direta sobre a informação dura da mudança climática em todas suas dimensões: negativas, positivas, novas oportunidades. Os meios de comunicação social massivos podem ser a chave para lograr este objetivo.


Assuntos
Conservação dos Recursos Naturais , Educação em Saúde Ambiental , Ética , Aquecimento Global , Responsabilidade Social , Efeito Estufa , Pós-Modernismo , Mídias Sociais
12.
PLoS One ; 9(10): e110301, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25338112

RESUMO

BACKGROUND: Biological invasions affecting rocky intertidal zonation patterns, yield information on species interactions. In the Bay of Antofagasta, northern Chile, the non-indigenous tunicate Pyura praeputialis, originally from Australia, has invaded (in the past century or so) and monopolized a major portion of the mid-intertidal rocky shore, displacing upshore the native mussel Perumytilus purpuratus. In Antofagasta the tunicate is subjected to intensive exploitation. Monitoring protocols show that in the past 10 years Antofagasta's tunicate population has experienced a drastic decline, affecting the intertidal zonation pattern. METHODOLOGY/PRINCIPAL FINDINGS: A 12.5 km of coastline, on the southern eastern shore of the Bay of Antofagasta, was studied. Eight sites were systematically (1993-1994) or sporadically (2003-2014) monitored for the seaward-shoreward expansion or reduction of the tunicate Pyura praeputialis, and native mussel and barnacle bands. A notable reduction in the mid-intertidal band of P. praeputialis and a seaward expansion of the mussel, Perumytilus purpuratus, and barnacle bands was observed. We suggest that the major cause for the decline in the tunicate is due to its intensive exploitation by rocky shore Pyura-gathers. The rate of extraction of tunicates by professional Pyura-gathers ranged between 256-740 tunicates hour-(1). Between 2009-2014 the density of professional Pyura-gather ranged between 0.5-4.5 km(-1) per low tide. Hence, 10 professional Pyura-gathers working 1 h for 10 low tides per month, during 6 months, will remove between 307-888 m(2) of tunicates. A drastic decline in tunicate recruitment was observed and several P. praeputialis ecosystems services have been lost. CONCLUSION AND SIGNIFICANCE: In Antofagasta, the continuous and intensive intertidal gathering of the invasive tunicate Pyura praeputialis, has caused a drastic reduction of its population modifying the zonation pattern. Thereby, native mussel Perumytilus purpuratus has regained its ecological center in the intertidal zone. We recorded a Pyura recruitment failure and loss of ecosystem services.


Assuntos
Bivalves/fisiologia , Conservação dos Recursos Naturais , Urocordados/fisiologia , Distribuição Animal , Animais , Baías , Chile , Ecossistema , Espécies Introduzidas , Reprodução/fisiologia
13.
Proc Natl Acad Sci U S A ; 111(42): 15042-7, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25288740

RESUMO

Numerous international bodies have advocated the development of strategies to achieve the sustainability of marine environments. Typically, such strategies are based on information from expert groups about causes of degradation and policy options to address them, but these strategies rarely take into account assessed information about public awareness, concerns, and priorities. Here we report the results of a pan-European survey of public perceptions about marine environmental impacts as a way to inform the formation of science and policy priorities. On the basis of 10,106 responses to an online survey from people in 10 European nations, spanning a diversity of socioeconomic and geographical areas, we examine the public's informedness and concern regarding marine impacts, trust in different information sources, and priorities for policy and funding. Results show that the level of concern regarding marine impacts is closely associated with the level of informedness and that pollution and overfishing are two areas prioritized by the public for policy development. The level of trust varies greatly among different information sources and is highest for academics and scholarly publications but lower for government or industry scientists. Results suggest that the public perceives the immediacy of marine anthropogenic impacts and is highly concerned about ocean pollution, overfishing, and ocean acidification. Eliciting public awareness, concerns, and priorities can enable scientists and funders to understand how the public relates to marine environments, frame impacts, and align managerial and policy priorities with public demand.


Assuntos
Ecossistema , Poluição Ambiental , Oceanos e Mares , Formulação de Políticas , Poluentes da Água/química , Acesso à Informação , Conscientização , Europa (Continente) , Humanos , Meios de Comunicação de Massa , Saúde Pública , Ciência , Inquéritos e Questionários
15.
Ambio ; 42(8): 975-84, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24213996

RESUMO

Tourism is a financing mechanism considered by many donor-funded marine conservation initiatives. Here we assess the potential role of visitor entry fees, in generating the necessary revenue to manage a marine protected area (MPA), established through a Global Environmental Facility Grant, in a temperate region of Chile. We assess tourists' willingness to pay (WTP) for an entry fee associated to management and protection of the MPA. Results show 97 % of respondents were willing to pay an entrance fee. WTP predictors included the type of tourist, tourists' sensitivity to crowding, education, and understanding of ecological benefits of the MPA. Nature-based tourists state median WTP values of US$ 4.38 and Sun-sea-sand tourists US$ 3.77. Overall, entry fees could account for 10-13 % of MPA running costs. In Chile, where funding for conservation runs among the weakest in the world, visitor entry fees are no panacea in the short term and other mechanisms, including direct state/government support, should be considered.


Assuntos
Conservação dos Recursos Naturais/economia , Oceanos e Mares , Chile , Comportamento do Consumidor/economia , Política Ambiental , Humanos , Modelos Logísticos , Natureza , Viagem
16.
J Anim Ecol ; 82(6): 1276-87, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23855822

RESUMO

1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.


Assuntos
Braquiúros/fisiologia , Conservação dos Recursos Naturais , Pesqueiros , Perciformes/parasitologia , Ouriços-do-Mar/parasitologia , Caramujos/parasitologia , Trematódeos/fisiologia , Animais , Chile , Brânquias/parasitologia , Interações Hospedeiro-Parasita , Densidade Demográfica
17.
Conserv Biol ; 26(6): 1005-15, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22971114

RESUMO

Territorial user rights for fisheries have been advocated as a way to achieve sustainable resource management. However, few researchers have empirically assessed their potential as ancillary marine conservation instruments by comparing them to no-take marine protected areas. In kelp (Lessonia trabeculata) forests of central Chile, we compared species richness, density, and biomass of macroinvertebrates and reef fishes among territorial-user-right areas with low-level and high-level enforcement, no-take marine protected areas, and open-access areas in 42 100-m subtidal transects. We also assessed structural complexity of the kelp forest and substratum composition. Multivariate randomized permutation tests indicated macroinvertebrate and reef fish communities associated with the different access regimes differed significantly. Substratum composition and structural complexity of kelp forest did not differ among access regimes. Univariate analyses showed species richness, biomass, and density of macroinvertebrates and reef fishes were greater in highly enforced territorial-user-right areas and no-take marine protected areas than in open-access areas. Densities of macroinvertebrates and reef fishes of economic importance were not significantly different between highly enforced territorial-user-right and no-take marine protected areas. Densities of economically important macroinvertebrates in areas with low-level enforcement were significantly lower than those in areas with high-level enforcement and no-take marine protected areas but were significantly higher than in areas with open access. Territorial-user-right areas could be important ancillary conservation instruments if they are well enforced.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros/legislação & jurisprudência , Peixes/fisiologia , Invertebrados/fisiologia , Animais , Biodiversidade , Biomassa , Chile , Ecossistema , Kelp , Análise Multivariada , Densidade Demográfica
18.
Proc Natl Acad Sci U S A ; 107(43): 18528-32, 2010 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-20937867

RESUMO

In open ecological systems, community structure can be determined by physically modulated processes such as the arrival of individuals from a regional pool and by local biological interactions. There is debate centering on whether niche differentiation and local interactions among species are necessary to explain macroscopic community patterns or whether the patterns can be generated by the neutral interplay of dispersal and stochastic demography among ecologically identical species. Here we evaluate how much of the observed spatial variation within a rocky intertidal metacommunity along 800 km of coastline can be explained by drift in the structure of recruits across 15 local sites. Our results show that large spatial changes in recruitment do not explain the observed spatial variation in adult local structure and that, in comparison with the large drift in structure of recruits, local adult communities converged to a common, although not unique, structure across the region. Although there is no unique adult community structure in the entire region, the observed variation represents only a small subset of the possible structures that would be expected from passive recruitment drift. Thus, in this diverse system our results do not support the idea that rocky intertidal metacommunities are structured by neutral mechanisms.


Assuntos
Ecossistema , Biologia Marinha , Animais , Chile , Invertebrados/crescimento & desenvolvimento , Modelos Biológicos , Dinâmica Populacional , Processos Estocásticos , Thoracica/crescimento & desenvolvimento
19.
Ecol Appl ; 20(6): 1504-11, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20945755

RESUMO

Unreliable and data-poor marine fishery landings can lead to a lack of regulatory action in fisheries management. Here we use official Chilean landing reports and non-conventional indicators, such as fishers' perceptions and spearfishing competition results, to provide evidence of reef fishes depletions caused by unregulated spearfishing. Results show that the three largest and most emblematic reef fishes targeted mainly by spearfishers (> 98% of landings) [Graus nigra (vieja negra), Semicossyphus darwini (sheephead or pejeperro), and Medialuna ancietae (acha)] show signs of depletion in terms of abundance and size and that overall the catches of reef fishes have shifted from large carnivore species toward smaller-sized omnivore and herbivore species. Information from two snorkeling speargun world championships (1971 and 2004, Iquique, Chile) and from fishers' perceptions shows the mean size of reef fish to be declining. Although the ecological consequences of reef fish depletion are not fully understood in Chile, evidence of spearfishing depleting temperate reef fishes must be explicitly included in policy debates. This would involve bans or strong restrictions on the use of SCUBA and hookah diving gear for spearfishing, and minimum size limits. It may also involve academic and policy discussions regarding conservation and fisheries management synergies within networks of no-take and territorial user-rights fisheries areas, as a strategy for the sustainable management of temperate and tropical reef fisheries.


Assuntos
Ecossistema , Pesqueiros , Peixes/fisiologia , Animais , Antozoários , Chile , Conservação dos Recursos Naturais , Oceanos e Mares
20.
Proc Natl Acad Sci U S A ; 106(38): 16298-303, 2009 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-19805296

RESUMO

We report a mechanism of crypsis present during the vulnerable early post-metamorphic ontogeny (95%) of specimens bearing patterns of shell coloration (dark or light colored) that matched the background coloration provided by patches of Concholepas' most abundant prey (mussels or barnacles respectively). The variation in shell color was positively associated with the color of the most common prey (r = 0.99). In laboratory experiments, shell coloration of C. concholepas depended on the prey-substrate used to induce metamorphosis and for the post-metamorphic rearing. The snail shell color matched the color of the prey offered during rearing. Laboratory manipulation experiments, switching the prey during rearing, showed a corresponding change in snail shell color along the outermost shell edge. As individuals grew and became increasingly indistinguishable from the surrounding background, cryptic individuals had higher survival (71%) than the non cryptic ones (4%) when they were reared in the presence of the predatory crab Acanthocyclus hassleri. These results suggest that the evolution of shell color plasticity during the early ontogeny of C. concholepas, depends on the color of the more abundant of the consumed prey available in the natural habitat where settlement has taken place; this in turn has important consequences for their fitness and survivorship in the presence of visual predators.


Assuntos
Adaptação Fisiológica/fisiologia , Pigmentação/fisiologia , Caramujos/fisiologia , Animais , Bivalves/fisiologia , Percepção de Cores/fisiologia , Ecossistema , Modelos Logísticos , Metamorfose Biológica , Comportamento Predatório/fisiologia , Caramujos/anatomia & histologia , Caramujos/crescimento & desenvolvimento
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