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ABSTRACT Determining the genetic structure and population dynamics of harvested species are key aspects of effective fisheries management. New Zealand scampi (Metanephrops challengeri) is a species of nethropid lobster that supports a commercial fishery on the continental shelf and slope around New Zealand. To determine the genetic structure and historical population demography of New Zealand scampi, we sequenced a 623 base-pair fragment of the mitochondrial gene cytochrome c oxidase subunit one (CO1) from 321 individuals across six widely separated sites off the coast of mainland New Zealand and the subantarctic Auckland Islands, representing much of the species’ distribution. The Auckland Islands population was found to be genetically distinct from all other sampled populations, potentially resulting from an absence of continuous suitable habitat between the central-eastern South Island and the Auckland Islands. An isolation-by-distance pattern of genetic structure was also detected. With the exception of the Mercury Islands, all sampled populations showed signs of recent population expansion, potentially linked to changes in habitat availability during the glacial-interglacial cycles of the Pleistocene. We recommend that the current NZ scampi management areas and harvesting rates for each remain unchanged. 相似文献
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Climate Dynamics - High-resolution simulations with a regional atmospheric model coupled to an intermediate-level mixed layer ocean model along with multiple atmospheric and oceanic reanalyses are... 相似文献
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Sydney T. Bacchus Douglas D. Archibald George A. Brook Kerry O. Britton Bruce L. Haines Stephen L. Rathbun Marguerite Madden 《水文研究》2003,17(9):1785-1809
Pond‐cypress (Taxodium ascendens Brong.) is a dominant canopy species in depressional wetlands of the south‐eastern Coastal Plain. Unsustainable withdrawals from the karst Floridan aquifer system have caused premature decline and death of pond‐cypress trees, presumably owing to altered hydroperiods (which alter the flow of water and nutrients in trees). There has been no scientifically based means to determine sustainable yield from this regional aquifer system or to detect early stages of physical/ecological damage associated with groundwater mining and aquifer storage and recovery (ASR, which also can alter natural hydroperiods). In this study, the relationship between visual symptoms (indicators) of stress or premature decline, and spectral reflectance was evaluated using dried, milled branch tips collected from natural stands of mature pond‐cypress. Depressional systems evaluated represented four of the six aquifer system subregions where subsurface perturbations from groundwater mining: (i) were presumed not to be occurring (reference wetlands); (ii) may be occurring but are not documented; and (iii) have been confirmed. Sampled trees were assigned to one of three stress classes (1, no/minimal; 2, moderate; 3, severe) based on the visual indicators. Partial least squares–linear discriminant analysis of second derivative spectral transformations in the visible/shortwave near‐infrared (NIR) region (400–1100 nm) and the NIR region (1100–2500 nm) was used to evaluate the samples in assigned classes. Class 1 samples were discriminated from combined class 2 and 3 samples in the NIR region with 100% and 97% accuracy for consecutive winter sample periods (before bud‐break). The percentage of correctly classified samples in this spectral region was lower (85%) for summer samples (full leaf‐out). Second‐derivative models for the NIR region developed from the winter data sets predicted assigned classes for alternate winter's samples with an accuracy of 97% and 100%. High correlation between spectral reflectance of dried, milled branch tips collected from mature pond‐cypress in winter and visual indicators of premature decline suggests in situ pond‐cypress are hydroecological indicators of anthropogenic subsurface hydroperiod perturbations. This approach provides objective means for early detection of unsustainable aquifer yield and adverse impacts from ASR activities in the south‐eastern Coastal Plain. Used in conjunction with hydrological monitoring and modelling, the hydroecological indicators should provide the means with which sustainable yield in the south‐eastern Coastal Plain can be achieved and maintained. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Massachusetts Institute of Technology general circulation model is used for the analysis of larval dispersal over Anton Dohrn Seamount (ADS), North Atlantic. The model output validated against the in situ data collected during the 136th cruise of the RRS ‘James Cook’ in May–June 2016 allowed reconstruction of the details of the baroclinic tidal dynamics over ADS. The obtained velocities were used as input data for a Lagrangian-type passive particle tracking model to reproduce the larval dispersal of generic deep-sea water invertebrate species. It was found that the residual tidal flow over ADS has a form of a pair of dipoles and cyclonic and anti-cyclonic eddies located at the seamount periphery. In the vertical direction, tides form upward motions above the seamount summit. These currents control local larval dispersal and their escape from ADS. The model experiment with a large number of particles (7500) evenly seeded on the ADS surface has shown that the trajectory of every individual particle is sensitive to the initial position and the tidal phase where and when it is released. The vast majority of the particles released above 1000 m depth remain seated in the same depth band where they were initially released. Only 8% of passive larvae were able to remain in suspension until competent to settle (maximise dispersal capability) and settle (make contact with the bottom) within the specified limits for this model. It was found that every tenth larval particle could leave the seamount and had a chance to be advected to any other remotely located seamount. 相似文献
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