Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Nature ; 580(7801): 39-51, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32238939

RESUMEN

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.


Asunto(s)
Ecosistema , Especies en Peligro de Extinción/estadística & datos numéricos , Restauración y Remediación Ambiental/tendencias , Biología Marina/tendencias , Animales , Extinción Biológica , Peces , Calentamiento Global/prevención & control , Actividades Humanas , Humanos
2.
Proc Natl Acad Sci U S A ; 118(23)2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-34083434

RESUMEN

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.


Asunto(s)
Variación Genética , Genómica , Genotipo , Especies Introducidas , Urocordados/genética , Animales , Australia , Chile
4.
Proc Natl Acad Sci U S A ; 114(24): 6167-6175, 2017 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-28584096

RESUMEN

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.


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Ecosistema , Adaptación Fisiológica , Animales , Organismos Acuáticos
5.
Conserv Biol ; 32(3): 619-627, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29114934

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Animales , Chile , Motivación , Alimentos Marinos
6.
Proc Natl Acad Sci U S A ; 111(42): 15042-7, 2014 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-25288740

RESUMEN

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.


Asunto(s)
Ecosistema , Contaminación Ambiental , Océanos y Mares , Formulación de Políticas , Contaminantes del Agua/química , Acceso a la Información , Concienciación , Europa (Continente) , Humanos , Medios de Comunicación de Masas , Salud Pública , Ciencia , Encuestas y Cuestionarios
8.
J Anim Ecol ; 82(6): 1276-87, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23855822

RESUMEN

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.


Asunto(s)
Braquiuros/fisiología , Conservación de los Recursos Naturales , Explotaciones Pesqueras , Perciformes/parasitología , Erizos de Mar/parasitología , Caracoles/parasitología , Trematodos/fisiología , Animales , Chile , Branquias/parasitología , Interacciones Huésped-Parásitos , Densidad de Población
9.
Proc Natl Acad Sci U S A ; 107(43): 18528-32, 2010 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-20937867

RESUMEN

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.


Asunto(s)
Ecosistema , Biología Marina , Animales , Chile , Invertebrados/crecimiento & desarrollo , Modelos Biológicos , Dinámica Poblacional , Procesos Estocásticos , Thoracica/crecimiento & desarrollo
10.
Ambio ; 42(8): 975-84, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24213996

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales/economía , Océanos y Mares , Chile , Comportamiento del Consumidor/economía , Política Ambiental , Humanos , Modelos Logísticos , Naturaleza , Viaje
11.
Conserv Biol ; 26(6): 1005-15, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22971114

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras/legislación & jurisprudencia , Peces/fisiología , Invertebrados/fisiología , Animales , Biodiversidad , Biomasa , Chile , Ecosistema , Kelp , Análisis Multivariante , Densidad de Población
12.
Proc Natl Acad Sci U S A ; 106(38): 16298-303, 2009 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-19805296

RESUMEN

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.


Asunto(s)
Adaptación Fisiológica/fisiología , Pigmentación/fisiología , Caracoles/fisiología , Animales , Bivalvos/fisiología , Percepción de Color/fisiología , Ecosistema , Modelos Logísticos , Metamorfosis Biológica , Conducta Predatoria/fisiología , Caracoles/anatomía & histología , Caracoles/crecimiento & desarrollo
13.
Ecol Appl ; 20(6): 1504-11, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20945755

RESUMEN

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.


Asunto(s)
Ecosistema , Explotaciones Pesqueras , Peces/fisiología , Animales , Antozoos , Chile , Conservación de los Recursos Naturales , Océanos y Mares
14.
Proc Natl Acad Sci U S A ; 104(46): 18120-2, 2007 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-17984045

RESUMEN

Here we report a mechanism that reduces dispersal of early developing stages and larvae in a free-spawning intertidal and shallow subtidal tunicate, Pyura praeputialis (Heller 1878), in the Bay of Antofagasta, Chile. The spawning of gametes by the tunicate into the naturally turbulent aerated seawater decreases their surface tension and induces the formation of a bio-foam. Water collected from foamy intertidal pools and tide channels showed a high concentration of P. praeputialis early developing stages and tadpole larvae in the foam. Because gametes are synchronically spawned for external fertilization and larvae settle near adults, our results suggest that this bio-foam increases fertilization success and effective settlement of their short-lived larvae in the vicinity of the adults spawning the gametes. This mechanism reinforces published evidence suggesting that local retention of intertidal and inshore marine invertebrate larvae may be more common than previously thought, offering, for instance, new perspectives for the design and networking of marine protected and management areas.


Asunto(s)
Larva/fisiología , Reproducción , Urocordados/fisiología , Animales , Fertilización , Urocordados/genética
15.
Ecol Appl ; 18(1): 273-81, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18372572

RESUMEN

To combine the rational use of marine benthic resources and economic development of small-scale fishers, Chile passed legislation in 1991 establishing a comanagement policy that grants exclusive territorial user rights for fisheries (TURFs) to artisanal fisher organizations in well-defined inshore coastal areas, known as Management and Exploitation Areas for Benthic Resources (MEABRs). In general the policy has been proclaimed a management and economic success because benthic resource abundances have increased inside MEABRs in comparison with open-access areas. However, there is a lack of studies assessing the impact of this management policy on nontargeted subtidal species and community assemblages and the policy's implications for biodiversity and conservation. This study starts to fill this gap and links the allocation of TURFs for benthic resources with add-on conservation benefits for species that are not directly linked with the fishery policy. Comparative subtidal surveys inside vs. outside MEABRs were used to assess the effects of three MEABRs on managed targeted benthic species, biodiversity (species richness), and community assemblages in central Chile. Surveys focused exclusively on subtidal kelp forest habitats dominated by Lessonia trabeculata, spanning 4-12 m in depth and with similar levels of habitat complexity. The study comprised: (1) quantification of kelp forest complexity, (2) understory survey of sessile species, (3) quantification of conspicuous benthic macroinvertebrates, including those under management, and (4) quantification of reef-fish species inside the kelp habitat. Results showed population enhancement of target-managed invertebrates inside MEABRs. Moreover, reef-fish species were significantly more diverse and abundant inside MEABRs, and community assemblages of nontarget benthic invertebrates and reef fish were significantly different inside vs. outside MEABRs. The comanagement of inshore benthic resources in Chile, through MEABRs aims for the sustainability of invertebrate and algae stocks. However, our study shows that this management tool, which in practice restricts access to the entire management area, provides important conservation add-on effects for species that are not the focus of the management policies. Therefore, in Chile, the hundreds of already established MEABRs could represent an important ancillary network, which complements the biodiversity objectives of fully protected areas such as no-take marine protected areas or others.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Biología Marina , Chile
16.
Ambio ; 46(6): 706-716, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28247340

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Animales , Chile , Ecología , Ecosistema , Peces
17.
Ambio ; 46(2): 184-189, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27530553

RESUMEN

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.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales/legislación & jurisprudencia
18.
Cuad Bioet ; 27(91): 403-414, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28092716

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales , Ecología/ética , Ecosistema , Salud Ambiental/ética , Cambio Climático , Humanos
20.
Am Nat ; 154(3): 341-357, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10506549

RESUMEN

Intertidal mussels usually form complex multilayered matrices with density-dependent effects on survival and growth, and self-thinning scaling between biomass (B) and density (N) is expected. This article develops a tridimensional model of space-driven self-thinning that in addition to B-N explicitly includes the degree of packing of the mussels, measured as the number of layers (L). The structure of our model (B-N-L) encompasses previous bidimensional models (B-N) of self-thinning as special cases and enables comparisons between mono- and multilayered populations. We contrast the predictions of the bi- and tridimensional models using data obtained from Perumytilus purpuratus mussel beds on the rocky shores of central Chile monitored during a 28-mo period. The tridimensional model suggests that density dependence is much more frequent than hitherto indicated by bidimensional models. We propose that our space-driven tridimensional model may be applied not only to mussels but also to other species where spatial overlapping configurations occur.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA