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151.
Michael Stat Jeffrey John Joseph D. DiBattista Stephen J. Newman Michael Bunce Euan S. Harvey 《Conservation biology》2019,33(1):196-205
Monitoring communities of fish is important for the management and sustainability of fisheries and marine ecosystems. Baited remote underwater video systems (BRUVs) are among the most effective nondestructive techniques for sampling bony fishes and elasmobranchs (sharks, rays, and skates). However, BRUVs sample visually conspicuous biota; hence, some taxa are undersampled or not recorded at all. We compared the diversity of fishes characterized using BRUVs with diversity detected via environmental DNA (eDNA) metabarcoding. We sampled seawater and captured BRUVs imagery at 48 locales that included reef and seagrass beds inside and outside a marine reserve (Jurien Bay in Western Australia). Eighty-two fish genera from 13 orders were detected, and the community of fishes described using eDNA and BRUVs combined yielded >30% more generic richness than when either method was used alone. Rather than detecting a homogenous genetic signature, the eDNA assemblages mirrored the BRUVs’ spatial explicitness; differentiation of taxa between seagrass and reef was clear despite the relatively small geographical scale of the study site (∼35 km2). Taxa that were not sampled by one approach, due to limitations and biases intrinsic to the method, were often detected with the other. Therefore, using BRUVs and eDNA in concert provides a more holistic view of vertebrate marine communities across habitats. Both methods are noninvasive, which enhances their potential for widespread implementation in the surveillance of marine ecosystems. 相似文献
152.
Tesfaye Fitsum Liu Xiaoyu Zheng Jufeng Cheng Kun Bian Rongjun Zhang Xuhui Li Lianqing Drosos Marios Joseph Stephen Pan Genxing 《Environmental science and pollution research international》2021,28(26):34108-34120
Environmental Science and Pollution Research - As one of the most important nutrients for plant growth, phosphorus was often poorly available in soil. While biochar addition induced improvement of... 相似文献
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156.
Extinction and Spatial Structure in Simulation Models 总被引:1,自引:0,他引:1
157.
Recovery of gray wolf ( Canis lupus ) populations in North America depends on minimizing human-caused mortality and enhancing migration from stable source populations to suitable habitat unoccupied by wolves. We used a combination of field observation and DNA microsatellite genotyping to examine natural wolf colonization of Glacier National Park, Montana, and surrounding lands. We found high genetic variation in the colonizing population, showing that these packs were founded by multiple, unrelated wolves from Canada. High dispersal rates, long dispersal distances, and lack of a founding population bottleneck indicate that wolves in the United States and Canada should be viewed and managed as a single population. Restoration in the United States by artificial transplants from Alberta to Yellowstone National Park and central Idaho began in 1995. The transplanted wolves will likely aid demographic recovery, but permanently retaining the high genetic variation of wolves in the United States will require assuring gene flow throughout the central Rocky Mountains. 相似文献
158.
Sardine (Sardina pilchardus) spawning seasonality in European waters of the northeast Atlantic 总被引:3,自引:0,他引:3
Yorgos Stratoudakis Stephen Coombs Ana Lago de Lanzós Nicholas Halliday Gersom Costas Bruno Caneco Concha Franco David Conway M. Begoña Santos Alexandra Silva Miguel Bernal 《Marine Biology》2007,152(1):201-212
Egg data from ichthyoplankton monitoring sites in the western English Channel (1988–2003) and northern Spain (1990–2000) and
macroscopic maturity data from biological samples of purse seine landings in western and southern Iberia (1980–2004) are used
to describe the spawning seasonality of sardine (Sardina pilchardus) in European waters of the northeast Atlantic using generalised additive models. The fitted models reveal a double peak in
spawning activity during early summer and autumn in the western Channel, a wider spring peak off northern Spain and a broad
winter season in the western and southern Iberian Peninsula. At all sites, a high probability of spawning activity was observed
over at least 3 months of the year, with the duration of the season increasing with both decreasing latitude and increasing
fish size. Off western and southern Iberia there are indications that the spawning season has been of longer duration in recent
years for all size classes (reaching in some cases 8 months of the year for large fish). These patterns are in general agreement
with existing literature and theoretical expectations of sardine spawning being driven locally by the seasonal cycle of water
temperature, assuming preferences for spawning at 14 –15°C and avoidance for temperatures below 12°C and above 16°C. Regional
quotient plots indicated that spawning tolerance to higher temperatures increases progressively with decreasing latitude.
Despite the weak evidence for geographical differences in temperature tolerance that may have some genetic origin, the degree
of spatio-temporal overlap in sardine-spawning activity within Atlantic European waters is unlikely to promote any reproductive
isolation in that area. 相似文献
159.
Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands. Annual occupancy and colonization for each species was estimated using recently developed models that incorporate detection probabilities to provide unbiased parameter estimates. We did not find negative effects of the fire on the occupancy or colonization rates of the long-toed salamander (Ambystoma macrodactylum). Instead, its occupancy was higher across the study area after the fire, possibly in response to a large snowpack that may have facilitated colonization of unoccupied wetlands. Naive data (uncorrected for detection probability) for the Columbia spotted frog (Rana luteiventris) initially led to the conclusion of increased occupancy and colonization in wetlands that burned. After accounting for temporal and spatial variation in detection probabilities, however, it was evident that these parameters were relatively stable in both areas before and after the fire. We found a similar discrepancy between naive and estimated occupancy of A. macrodactylum that resulted from different detection probabilities in burned and control wetlands. The boreal toad (Bufo boreas) was not found breeding in the area prior to the fire but colonized several wetlands the year after they burned. Occupancy by B. boreas then declined during years 2 and 3 following the fire. Our study suggests that the amphibian populations we studied are resistant to wildfire and that B. boreas may experience short-term benefits from wildfire. Our data also illustrate how naive presence-non-detection data can provide misleading results. 相似文献
160.
Humans visiting natural areas often disturb wildlife, possibly displacing animals from desirable habitat. To hold ecotourism at acceptable levels refuge managers need to know which species are likely to be affected and which response occurs at different levels of disturbance. Displacement of waterbirds at J. N. "Ding" Darling National Wildlife Refuge, Florida (U.S.A.), by specific human activities was demonstrated experimentally by Klein in 1993. We assessed the extent of this effect of ecotourism on the distribution of 38 species of waterbirds by surveying birds in plots of known distance from a dike along which wildlife tours occurred. Most resident species were less sensitive to disturbance than were migrants. Migrant ducks were most sensitive when they first arrived, mid-October to mid-December, usually remaining more than 80 m from the drive, even at low levels of human visitation. Herons, egrets. Brown Pelicans ( Pelecanus occidentalis ), and Anhingas ( Anhinga anhinga ) were most likely to remain close to areas of high human activity. Shorebirds were displaced at intermediate distance and visitation levels. Mottled Ducks ( Anas fulvigula ) and several of the ardeids seemed to include two groups differing in behavior, one habituated to humans and one sensitive to disturbance. Public education and changes in management practices are needed to reduce disturbance. Guided tours and low-disturbance zones where people stay in their cars could reduce the negative effects of tourists, especially in the fall when migrants arrive. The number of human visitors may have to be reduced or the wildlife drive closed on certain days during the tourist season. 相似文献