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Shiang‐Lin Huang Haiping Wu Xianyan Wang Chongwei Peng Chun‐Chieh Wang 《水产资源保护:海洋与淡水生态系统》2020,30(9):1775-1782
- Protecting critical habitats of the Indo‐Pacific humpback dolphin, Sousa chinensis, is a hot topic of discussion for marine biodiversity conservation in China and many Southeast Asian countries. In practice, sound habitat protection action (HPA) planning often suffers from information gaps in macroscopic habitat configurations and changes in the habitat conditions of humpback dolphins.
- Recent publications in the journal Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) have served to advance humpback dolphin conservation in Chinese waters by resolving such habitat configurations and indicating significant changes in distribution patterns and habitat characteristics under intense coastal anthropogenic activity.
- We highlight an integrative research framework to investigate habitat configuration and long‐term habitat changes when planning a holistic HPA programme for humpback dolphins. When constructing habitat configuration baselines, field surveys should be designed and conducted in a systematic manner to ensure survey efforts cover diverse environments equally, in either a spatially stratified or gridded pattern, to minimize potential spatial sampling biases. Long‐term habitat changes can be revealed by comparing satellite images from different decades. Changes in habitat preferences and habitat characteristics can be explored through questionnaire surveys on local ecological knowledge, associating historical occurrences with coastline features and projecting historical habitat configuration by species distribution modelling exercises.
- A lack of good communication and sharing of information between research and management sectors can still be an obstacle to the implementation of sound conservation practices, however, even though there is robust scientific evidence to fill knowledge gaps in distribution and habitat baselines. We have addressed the need to establish a mechanism to improve and streamline information sharing between research teams, management sectors, and stakeholder groups.
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Leandro Nole Eduardo Arnaud Bertrand Thierry Frdou Alex Souza Lira Rayssa Siqueira Lima Beatrice Padovani Ferreira Frdric Menard Flvia Lucena‐Frdou 《水产资源保护:海洋与淡水生态系统》2020,30(4):761-774
- Tetraodontiformes fishes play a critical role in benthic and demersal communities and are facing threats due to anthropogenic impacts and climate change. However, they are poorly studied worldwide. To improve knowledge on the socio‐ecological significance and conservation of Tetraodontiformes a review of literature addressing the diversity, ecology, use and trade, conservation, and main threats of Tetraodontiformes combined with a comprehensive in situ dataset from two broad‐range multidisciplinary oceanographic surveys performed along the Tropical Brazilian Continental Shelf was undertaken.
- Twenty‐nine species were identified, being primarily found on coral reefs and algal ecosystems. At these habitats, tetraodontids present highly diversified trophic categories and might play an important role by balancing the marine food web
- Coral reef ecosystems, especially those near to the shelf break, seem to be the most important areas of Tetraodontiformes fishes, concentrating the highest values of species richness, relative abundance and the uncommon and Near Threatened species.
- Ninety per cent of species are commonly caught as bycatch, being also used in the ornamental trade (69%) and as food (52%), serving as an important source of income for artisanal local fisheries.
- Tetraodontiformes are threatened by unregulated fisheries, overexploitation, bycatch, and habitat loss due to coral reef degradation and the potential effects of climate change. These factors are more broadly impacting global biodiversity, food security, and other related ecosystem functions upon which humans and many other organisms rely.
- We recommend the following steps that could improve the conservation of Tetraodontiformes along the tropical Brazilian Continental shelf and elsewhere: (i) data collection of the commercial, incidental, ornamental and recreational catches; (ii) improvement of the current legislation directed at the marine ornamental harvesting; (iii) increase efforts focused on the education and conservation awareness in coastal tourism and communities; and, most important, (iv) creation of marine reserves networks in priority areas of conservation, protecting either the species and key habitats for its survival.
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Pablo del Monte-Luna Daniel Lluch-Belda Elisa Serviere-Zaragoza Roberto Carmona Héctor Reyes-Bonilla David Aurioles-Gamboa José Luis Castro-Aguirre Sergio A. Guzmán del Próo Oscar Trujillo-Millán & Barry W. Brook 《Fish and Fisheries》2007,8(2):107-122
In recent years, more than 130 extinctions have been estimated to have occurred in the marine realm. Here we review this body of evidence and show that this figure may actually be overestimated by as much as 50%. We argue that previous estimates have not fully taken into account critical uncertainties such as naturally variable geographical distributions, and have misinterpreted documentary evidence. However, current evidence indicates that some sharks, rays and reef‐associated species, although not necessarily geographically restricted, are particularly vulnerable to anthropogenic impacts and now occur in very low numbers. Overestimating extinctions is of concern because it could reduce confidence in the credibility of the ‘extinct’ category in threatened species lists and, ultimately, be used to question the integrity of conservation and management policies. We suggest that when integrating future checklists of marine extinct species, there needs to be a more rigorous use of the terminology of extinction, and participation by specialists in each of the particular taxonomic groups involved. 相似文献
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Julio L. Lancelotti Natalia L. Pessacg Ignacio C. Roesler Miguel A. Pascual 《水产资源保护:海洋与淡水生态系统》2020,30(3):554-564
- The population of the critically endangered hooded grebe (Podiceps gallardoi) has decreased drastically during recent decades. The effects of climate change on their reproductive area (Southern Patagonia) have been proposed as one of the potential causes of their critical situation. However, there is much uncertainty about climate variability and climate trends at local scales in Patagonia, and their effects on the hooded grebe habitat.
- Variability and trends in temperature, precipitation, and wind from 1960 to 2016 in one of the most important reproductive areas of hooded grebe – the Lake Strobel plateau – were analysed. A Landsat satellite image series (1973–2016) was used to evaluate changes in lake area in the region.
- Generalized linear models were used to analyse the relationship between the variation in lake area and climatic variables, including the Antarctic Oscillation Mode (AAO) index, which is the most important year to year pattern in climate variability at high latitudes of the Southern Hemisphere.
- High inter‐annual variability and increasing coefficients of variation in precipitation and wind were found, as well as a significant positive trend in temperature. Total lake area, as well as the area specifically used by hooded grebe to reproduce, decreased significantly over time, with high inter‐annual variability. Variation in lake area was significantly correlated with variation in precipitation, and with the AAO index.
- The loss of reproductive habitat may force the hooded grebe to use sub‐optimal environments, such as lakes with lower food supply, lower macrophyte cover, and less protection from wind – a potential major handicap for this declining species.
- Information on lake variation in response to climatic variability could be used to guide hooded grebe conservation strategies, directing more resources and special efforts to those reproductive lakes that are more resilient to the effects of climate fluctuations.
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Daniel S. Swadling Greg J. West Peter T. Gibson Roger J. Laird Tim M. Glasby 《水产资源保护:海洋与淡水生态系统》2023,33(1):56-69
- Although it is well established that human activities are linked to the loss of seagrasses worldwide, the influence of anthropogenic disturbances on the habitat fragmentation of seagrass meadows is less understood. This information is essential to identify how humans are modifying seascapes and what disturbances pose the greatest risk to seagrasses, which is pertinent given the rapid urbanization occurring in coastal areas.
- This study examined how the habitat fragmentation of an endangered seagrass Posidonia australis varied in relation to several anthropogenic disturbances (i.e. human population, marine infrastructure, terrestrial run-off and catchment land-usage) within 10 estuaries across 620 km of coastline in New South Wales, Australia.
- When comparing between estuaries, the fragmentation of P. australis meadows was significantly greater in estuaries adjacent to highly populated metropolitan centres – generally in the Greater Sydney region. At sites within estuaries, the density of boat moorings was the most important predictor of habitat fragmentation, but there was also evidence of higher fragmentation with increased numbers of jetties and oyster aquaculture leases.
- These results suggest that the fragmentation of seagrass meadows will become more pervasive as the human population continues to grow and estuarine development increases. Strategies to mitigate anthropogenic disturbances on seagrass meadow fragmentation could include prohibiting the construction of boat moorings and other artificial structures in areas where seagrasses are present or promoting environmentally friendly designs for marine infrastructure. This knowledge will support ongoing management actions attempting to balance coastal development and the conservation of seagrasses.
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Abstract – We investigated the variations of population of two cyprinids, Varicorhinus alticorpus and Varicorhinus barbatulus , using long-term survey data (1995–2004) in the subtropical island of Taiwan. Fish abundance data showed that at the mainstem stations, V. barbatulus which used to dominate in the higher altitude had declined significantly, while V. alticorpus that used to occupy only the lower altitude had spread upward. However, at the tributaries, trend of the populations of V. barbatulus were not significantly different over time, while populations of V. alticorpus were absent at higher altitude but began to increase at lower altitude. Environmental parameters revealed that sporadic high turbidity was observed at the mainstem stations, but not at the tributaries. Images taken before and after typhoon also showed habitat destruction by debris flow at the mainstem stations. As some models predicted that suitable fish habitats will shrink because of increasing water temperature due to global warming, we showed that fish distribution may be affected by habitat disturbance due to intensified storms sooner than the actual increase of water temperature. 相似文献
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Edward E. DeMartini 《Fish and Fisheries》2019,20(6):1246-1259
Surprisingly little published information exists on the pros and cons of managing extracted resources that are pooled as compound taxa such as species complexes. Current fisheries management includes many species complexes; in Hawaii, this includes two taxa of species pooled at subfamily and higher levels. These include seven species of parrotfishes (Scarinae, Labridae) and a seven‐species ‘bottomfish’ complex (the ‘Deep‐7’: comprising six species of snappers [Etelinae, Lutjanidae] and a single species of grouper [Epinephelidae]). Recent research on key vital rates (growth, reproduction) for major species in both taxa indicates that these complexes consist of species with disparate life histories. Species in the parrotfish taxon exhibit fast to very fast growth and short to moderate longevities, whilst Deep‐7 bottomfishes exhibit moderate to very slow growth and long to very long lifespans. These data clearly indicate that, although pooling species is a tempting default option in data‐poor situations, it is at best a necessary evil to be avoided when sufficient data on the demographics of component species become available. Pooling species is especially problematic when the ecosystem effects of extracting functionally dominant species should be an important management consideration in addition to that of species demographics. Assessments that recognize and quantify the ecosystem importance of habitat engineers and other ecological dominants could substantively improve management of species complexes. Ultimately, complexes of resource species need to be evaluated and managed based on many, sometimes conflicting and sometimes reinforcing, but always careful considerations such as those contrasted herein between the parrotfishes and bottomfishes of Hawaii. 相似文献
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1. The effect of habitat fragmentation was investigated in two adjacent, yet separate, intertidal Zostera marina beds in the Salcombe Estuary, Devon, UK. The seagrass bed on the west bank comprised a continuous meadow of ca. 2.3 ha, whilst the bed on the east bank of the estuary was fragmented into patches of 6–9 m2. 2. Three 10 cm diameter core samples for infaunal macroinvertebrates were taken from three stations within each bed. No significant difference was found in univariate community parameters between beds, or in measured seagrass parameters. However, multivariate analysis revealed a significant difference in community composition, due mainly to small changes in species abundance rather than differences in the species present. 3. The species contributing most to the dissimilarity between the two communities were polychaetes generally associated with unvegetated habitats (e.g. Magelona mirabilis) and found to be more common in the fragmented bed. 4. A significant difference in median grain size and sorting coefficient was recorded between the two beds, and median grain size was found to be the variable best explaining multivariate community patterns. 5. The results of the study provide evidence for the effects of habitat fragmentation on the communities associated with seagrass beds, habitats which are of high conservation importance. As the infaunal community is perhaps intuitively the component least likely to be affected by fragmentation at the scale observed, the significant difference in community composition recorded has consequences for more sensitive and high‐profile parts of the biota (e.g. fish), and thus for the conservation of seagrass habitats and their associated communities. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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鸟类对生态系统变化较为敏感,是衡量生态环境质量变化的一种重要指示生物;气候变化已成为栖息地丧失的重要原因之一,对鸟类的迁徙、繁殖有一定的影响。为了探究未来气候变化条件下鸟类栖息地适宜性分布,以洞庭湖流域为研究区域,结合收集到的382个鸟类出现点数据、遥感影像数据、气候变化数据等,基于Maxent模型方法,综合分析驱动洞庭湖流域鸟类分布的气候因素,并预测2050年气候不同情景下鸟类栖息地适宜性分布特征。结果显示,历史情景下洞庭湖流域鸟类的适宜性栖息地为多个集中分布区组成的带状区域,而在未来情景下栖息地由以前的带状分布逐渐演变为团状分布。在2050年RCP2.6、RCP4.5排放情景下,适宜栖息地面积有所下降,占研究区域总面积的比例从历史情景的9.43%分别降至9.26%、8.91%;而在RCP8.5排放情景下面积有所增加,占研究区域总面积的比例增加至10.22%。从适宜性分布来看,栖息地变得更加集中,未来情景下鸟类栖息地适宜性在3种排放情景下略高于历史情景,适宜性RCP8.5情景(33.12%)>RCP2.6情景(32.87%)>RCP4.5情景(32.74%)>历史情... 相似文献
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Miranda C. Jones Stephen R. Dye John k. Pinnegar Rachel Warren William W.L. Cheung 《水产资源保护:海洋与淡水生态系统》2013,23(5):710-722
- The inherent complexity of the environment is such that attempts to model it must operate under simplifications and assumptions. Considering predictions from alternative models, with a range of assumptions and data requirements, therefore provides a more robust approach.
- The intractability and uncertainty resulting from a suite of predictions may hinder the application of science in policy, where a single prediction with little ambiguity or uncertainty would be most desirable. Few studies modelling species' distributions attempt to present multi‐model outputs in a format most useful to the non‐modelling community, and none of these have done so for the marine environment.
- The problem of uncertainty is particularly prevalent in predicting the distribution of invasive alien species under climate change. As invasive alien species are one of the main drivers of biodiversity loss and may incur significant economic costs, the benefit of applying predictions to highlight areas of possible establishment and inform policy and management may be large.
- An ensemble prediction is used to assess the distribution of suitable habitat for the Pacific oyster, Crassostrea gigas, in UK waters both currently and in the future. The ensemble incorporates predictions from three species distribution models, using data from two global climate models. A method is developed highlighting the agreement of the ensemble, further applying threshold values to retain information from constituent predictions in the final map of agreement.
- Ensemble predictions made here suggest that Pacific oyster will experience an opening of suitable habitat in northern UK waters, reaching the Faroe Islands and the eastern Norwegian Sea by 2050. Habitat suitability will increase with warming temperatures in the English Channel and Central North Sea for this species. The approaches applied here can be incorporated into risk assessment frameworks for invasive species, as stipulated in the Convention on Biological Diversity.
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- Intertidal habitat maps are needed at both fine and coarse scales to monitor change and inform conservation and management, but current methods of field survey and expert interpretation of aerial imagery can be time‐consuming and subjective. Object‐based image analysis (OBIA) of remote sensing data is increasingly employed for producing habitat or land cover maps. Users create automated workflows to segment imagery, creating ecologically meaningful objects, which are then classified based on their spectral or geometric properties, relationships to other objects and contextual data.
- This study evaluates the change‐detection capability of OBIA in the intertidal environment by developing and comparing two OBIA methods for quantifying change in extent and distribution of habitats from freely available multi‐temporal aerial imagery and LiDAR data. Despite considerable variability in the data, pre‐ and post‐classification change detection methods had sufficient accuracy (mean overall accuracy from 70.5 to 82.6%) to monitor deviation from a background level of natural environmental fluctuation.
- This insight into spatial and temporal patterns of natural cyclical change and their detectability by OBIA could inform use of remote sensing for regular, rapid coastal assessment, providing an alert system to direct survey resources to areas of ecologically relevant change.
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An assessment of climate change impacts on the habitat suitability of fish species is an important tool to improve the understanding and decision‐making needed to reduce potential climate change effects based on the observed relationships of biological responses and environmental conditions. In this study, we use historical (2010–2015) environmental sea surface temperature (SST), upwelling index (UI), chlorophyll‐a (Chl‐a) and biological (i.e., anchovy adults acoustic presence) data (i.e., Maxent) to determine anchovy habitat suitability in the coastal areas off central‐northern (25°S–32°S) Chile. Using geographic information systems (GIS), the model was forced by changes in regionalized SST, UI and Chl‐a as projected by IPCC models under the RPC (i.e., RCP2.6, RCP4.5, RCP6.0 and RCP8.5) emissions scenarios for the simulation period 2015–2050. The model simulates, for all RCP scenarios, negative responses in anchovy presence, reflecting the predicted changes in environmental variables, dominated by a future positive (warming) change in SST and UI, and a decrease in chlorophyll‐a (i.e., phytoplankton biomass). The model predicts negative changes in habitat suitability in coastal areas from north of Taltal (25°S) to south of Caldera (27°45′S) and in Coquimbo littoral zone (29°–30°12′S). The habitat suitability models and climate change predictions identified in this study may provide a scientific basis for the development of management measures for anchovy fisheries in the coastal areas of the South American coast and other parts of the world. 相似文献
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River systems throughout arid regions worldwide have been heavily impacted by human activities, resulting in long‐term ecological consequences. The lower Pecos River in the Trans‐Pecos region of Texas is no exception, having undergone anthropogenic changes that include decreased flow, elevated salinity, species loss and species invasion. We compared historical and contemporary fish assemblage attributes from the Pecos River at local (site‐specific) and regional (Trans‐Pecos region) scales across a 24‐year time period. Fish assemblage data were collected in October 1987 and 2011, by seining at 15 sites spanning 430 km of the river in Texas. Additionally, we examined contemporary environmental conditions to determine species–environment relationships. We found that fish assemblages were significantly different between time periods, likely due to increased salinisation in the upper half of the study region. Decreased species richness, species replacement and increases in euryhaline species were documented in the upstream sites. Freshwater springs lower the salinity and maintain flows in the downstream reach, allowing for maintenance of the native fish fauna. Careful management of regional aquifers, irrigation practices and petroleum waste water will be necessary for protecting biodiversity and environmental flows in the lower Pecos River. 相似文献
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- 1. Projected sea‐level rise (SLR) is expected to cause shoreline erosion, saline intrusion into the water table and inundation and flooding of beaches and coastal areas. Areas most vulnerable to these physical impacts include small, tropical low‐lying islands, which are often key habitat for threatened and endemic species, such as sea turtles.
- 2. Successful conservation of threatened species relies upon the ability of managers to understand current threats and to quantify and mitigate future threats to these species. This study investigated how sea‐level rise might affect key rookeries (nesting grounds) (n=8) for the northern Great Barrier Reef (nGBR) green turtle population, the largest green turtle population in the world.
- 3. 3‐D elevation models were developed and applied to three SLR scenarios projected by the IPCC 2007 and an additional scenario that incorporates ice melting. Results indicate that up to 38% of available nesting area across all the rookeries may be inundated as a result of SLR.
- 4. Flooding, as a result of higher wave run‐up during storms, will increase egg mortality at these rookeries affecting the overall reproductive success of the nGBR green turtle population. Information provided will aid managers to prioritize conservation efforts and to use realistic measures to mitigate potential SLR threats to the nGBR green turtle population. Copyright © 2009 John Wiley & Sons, Ltd.
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Anthea L. Mitchell Richard M. Lucas Brian E. Donnelly Kirrilly Pfitzner Anthony K. Milne Max Finlayson 《水产资源保护:海洋与淡水生态系统》2007,17(5):446-467
- 1. Using colour aerial photography, a set of fine (～1 m) spatial resolution orthomosaics and accompanying Digital Elevation Models (DEMs) were generated for the majority of mangroves in Kakadu National Park, Northern Australia, from which their extent and canopy height have been mapped.
- 2. The orthomosaics and DEMs, which were based on 68 stereo pairs acquired in 1991, cover an area of approximately 742 km2 and a coastal distance of 86 km. The DEMs have a height resolution of approximately ± 1 m.
- 3. The entire mosaic represents a key historical baseline data set of the extent and height of mangroves within the Park against which to observe and quantify changes in response to, for example, sea‐level rise.
- 4. The data sets will be available to assist management of the coastal environment and also to provide a unique insight into the distribution, dynamics and condition of mangroves. The techniques used are applicable to mangroves and other forested wetlands in other regions of Australia and elsewhere.
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《水产资源保护:海洋与淡水生态系统》2018,28(1):55-67
- DNA‐based studies have uncovered cryptic species and lineages within almost all freshwater fishes studied thus far from the Cape Fold Ecoregion (CFE) of South Africa. These studies have changed the way the CFE is viewed, as almost all stream fishes that were previously considered to be of low conservation priority, because they were perceived to have broad geographical ranges, contain multiple historically isolated lineages, many of which are narrow‐range endemics.
- As stream fishes of the CFE are of conservation concern owing to threats mainly posed by habitat degradation, invasion by alien species and hydrological modification, re‐evaluation of the distribution and conservation status of newly identified unique lineages is required to inform the development and implementation of effective conservation and management strategies.
- The present study conducted an IUCN Red List conservation assessment of a newly identified lineage of the Galaxias zebratus species complex (hereafter referred to as Galaxias sp. ‘Joubertina’) to identify key threats and provide recommendations to conservation authorities on appropriate measures to reduce extinction risk.
- The lineage met the qualifying threshold for the Endangered category because of its very restricted geographic range, few remaining secure populations, small known population sizes and the intensity of threats to most of the populations. Only six populations remain, one of which could be an ‘extralimital’ population potentially established through an inter‐basin water transfer scheme.
- Galaxias sp. ‘Joubertina’ is threatened by invasive piscivores, habitat degradation and excessive water abstraction. These impacts have fragmented remnant populations, raising concerns about potential long‐term adverse impacts on genetic diversity and evolutionary potential of this lineage.
- Immediate conservation measures should protect remnant populations from further impacts, while long‐term measures should aim to restore historical connectivity to reduce the potential deleterious effects of inbreeding in the small isolated populations.
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Potential impact of climate warming on recreational fishing opportunities for Atlantic salmon, Salmo salar L., in Newfoundland, Canada 总被引：1，自引：1，他引：1
Potential impacts of climate warming on recreational fishing opportunities were addressed by assessing the frequency and extent that Atlantic salmon, Salmo salar L., rivers in Newfoundland have been closed over a 25-year period (1975 to 1999) because of warm water temperatures and low water levels. On average, approximately 28% of all salmon rivers were temporarily closed annually, with over 70% affected in some years. This has resulted in a loss of 35–65% of the potential fishing days available in some salmon fishing areas with the collective 1995 to 1999 period being impacted the most over the past two decades. Geographically, west and south-west coastal rivers were affected less from environmental closures than east and some south coast fishing areas. A trend for increased closures of rivers related to environmental reasons could reduce the economic importance of the recreational salmon fishery and also make it more difficult to assess the status of Atlantic salmon stocks, which is a requirement for conservation of the resource. 相似文献
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- Northern elephant seals (Mirounga angustirostris) historically experienced a significant population decrease to the brink of extinction owing to human exploitation, but have since recovered and recolonized former breeding/haul‐out sites. Point Reyes Peninsula, California, is one location where population increase has resulted in colony expansion.
- Initial models identified suitable breeding haul‐outs and suggested that human disturbance, geomorphology, mean wave height, and slope were important explanatory variables. Three sea‐level rise (SLR) scenarios were run, which indicated that most current and potential haul‐out sites would largely be inundated by 2050. Because the Point Reyes coast has limited suitable habitat for the seals to colonize, conservation measures may guide management responses to SLR.
- The resulting analyses can be used to better understand local‐scale seal responses to SLR and contribute to effective management of pinnipeds within Point Reyes National Seashore and elsewhere. Copyright © 2012 John Wiley & Sons, Ltd.