260 research outputs found
A Target Fish Community to Guide River Restoration
No full textA method is proposed and demonstrated to specify a fish community to serve as a target for planning river restoration projects and as an endpoint for evaluating programme progress. Our target fish community is appropriate for small rivers in southern New England with basins characterized by dispersed human activities. Our study was part of a multi-agency improvement effort of the Quinebaug River in southern Massachusetts and northeast Connecticut, USA. We identify fish species expected to be found in streams, lakes, and river reaches of the Quinebaug River basin. An expected rank order of abundance was computed using fish surveys from rivers identified by restoration programme managers as being in a desirable condition for a human-dominated landscape. The rank order of species was converted to expected community proportions following a theoretical log–log relation between species abundances and occurrences in complex communities. Criteria from a committee of agency and water use representatives were influential in specifying a target community; so the overall method blends policy, objective zoogeography analyses, and theory-based parameters of community structure. We believe the use of a target community can be an important element in the design and evaluation of river restoration where the aim cannot be to copy pristine, natural ecosystem properties.Peer reviewe
Predicting ecological outcomes of stream creation using fish community attributes
No full textWe demonstrated an approach for predicting a new stream environment and the fishes it can support in terms of species composition, population density, and biomass. The challenge was to depict the future of a flowing stream in a setting where no present stream existed. The habitat of the Peconic River was field–surveyed and digitally mapped for three water–level conditions: run, glide and pool. Biomass estimates, in g/m2, were calculated for species historically found in the river, and species percent biomass was used to determine the number of each species likely to occur in each habitat type. The total biomass for all sites in each habitat type was averaged to predict biomass per unit area by habitat type. Biomass was then linked to habitat type to enable an estimate of where each fish species would be located and in what proportions. Biomass was predicted to increase with the amount of water in the Peconic River system. Pools are expected to exist with greater frequency at low and mid water and runs are expected to be more prevalent at high water. Glides are only expected when water levels are low. The total predicted biomass for the Peconic River study section in low water is expected to be 7 kg for glides, 13 kg for runs and 11 kg for pools. In mid water, 34 kg of biomass is expected for runs and 88 kg for pools. In high water, 370 kg of biomass is expected for runs and 62 kg for pools. Chain pickerel (Esox niger) is expected to comprise the highest biomass in all habitat types at all water levels. The results from this study are important to decision makers seeking a solution to an environmental problem through creation of a waterway in a heavily populated and altered environmental setting.Peer reviewe
Modeling Aquatic Macroinvertebrate Richness Using Landscape Attributes
No full textWe used a rapid, repeatable, and inexpensive geographic information system (GIS) approach to predict aquatic macroinvertebrate family richness using the landscape attributes stream gradient, riparian forest cover, and water quality. Stream segments in the Allegheny River basin were classified into eight habitat classes using these three landscape attributes. Biological databases linking macroinvertebrate families with habitat classes were developed using life habits, feeding guilds, and water quality preferences and tolerances for each family. The biological databases provided a link between fauna and habitat enabling estimation of family composition in each habitat class and hence richness predictions for each stream segment. No difference was detected between field collected and modeled predictions of macroinvertebrate families in a paired t-test. Further, predicted stream gradient, riparian forest cover, and total phosphorus, total nitrogen, and suspended sediment classifications matched observed classifications much more often than by chance alone. High gradient streams with forested riparian zones and good water quality were predicted to have the greatest macroinvertebrate family richness and changes in water quality were predicted to have the greatest impact on richness. Our findings indicate that our model can provide meaningful landscape scale macroinvertebrate family richness predictions from widely available data for use in focusing conservation planning efforts.Peer reviewe
A Water Quality Model for Regional Stream Assessment and Conservation Strategy Development
No full textNonpoint-source (NPS) pollution remains the primary source of stream impairment in the United States. Many problems such as eutrophication, sedimentation, and hypoxia are linked with NPS pollution and reduced water quality for aquatic and terrestrial organisms. Increasingly, NPS pollution models have been used for landscape scale pollution assessment and conservation strategy development. Our modeling approach functions at a scale between simple landscape level assessments and complex, data intensive modeling by providing a rapid, landscape scale geographic information system (GIS) model with minimal data requirements and widespread applicability. Our model relies on curve numbers, literature-derived pollution concentrations, and land status to evaluate total phosphorus (TP), total nitrogen (TN) and suspended solids (SS) at the reach scale. Model testing in the Chesapeake Bay watershed indicated that predicted distributions of water quality classes were realistic at the reach scale but precise estimates of pollution concentrations at the local scale can have errors. Application of our model in the tributary watersheds along Lake Ontario suggested that it is useful to managers in watershed planning by rapidly providing important information about NPS pollution conditions in areas where large data gaps exist, comparisons among stream reaches across numerous watersheds are required, or regional assessments are sought.Peer reviewe
Landscape scale assessment of stream channel and riparian habitat restoration needs
No full textHuman modifications of streams and rivers have caused extensive stream channel and riparian degradation. Cost-effective, rapid assessment tools can be used to better manage such areas by identifying the status of habitats for restoration planning and protection. We used a spatially explicit, reach-scale geographic information system modeling strategy to examine stream channel and riparian condition and prioritize restoration actions. The stream channel condition index uses information on land use, road and railroad density, and sinuosity. The riparian condition index uses calculations of percent forest, patch density, and convexity based on land cover in the floodplain. Reaches were classified into restoration categories based on stream channel and riparian condition model results, land ownership, slope, position in the subwatershed, and adjacency to high-quality habitat. We compared modeled restoration priority rankings with those in the management plan for the East Credit subwatershed in Ontario, Canada. Predicted stream channel restoration priority rankings matched field-based classifications for 86% of the reaches in the East Credit subwatershed. Predicted riparian restoration priority rankings matched field-based classifications for 81% of the reaches. Our methods replicate with fairly good accuracy the results obtained using intensive field surveys and stakeholder input. Managers can use these cost-effective strategy development tools to identify candidate reaches for further study and prioritize stream channel and riparian restoration actions over large regions.Peer reviewe
A GIS Framework for Fish Habitat Prediction at the River Basin Scale
No full textWe present a geographic information system (GIS) framework to classify stream habitats and provide fish distribution predictions comprehensively at the landscape scale. Stream segments were classified into one of eighteen habitat types using three landscape attributes: stream size (three categories), stream quality (three categories), and water quality (two categories). An extensive literature search was undertaken to classify fish species into the same eighteen habitat types based on preferences for the three landscape attributes. We tested our framework in 39 sites throughout the upper Allegheny River basin in western New York. No difference was detected between observed and predicted numbers of fish species among stream habitats. Further, field collected bankfull width measurements, stream quality ratings, and water quality sampling results were largely consistent with predicted values. The habitat type expected to have the greatest fish species richness was large streams or small rivers with intact stream quality and suitable water quality. Our framework is rapidly applied, comprehensive, inexpensive, and built on widely available data thereby offering an efficient alternative to traditional field-based efforts for regional habitat classification and fish distribution prediction
Aquatic gap analysis: tool for watershed scale assessment of fluvial habitat and biodiversity
No full textMethods for the conservation of stream habitat and biodiversity at the watershed scale have not been developed. Watersheds span large land areas, encompass a connected range of stream sizes, and integrate natural and altered properties of a drainage area. Methods are needed to identify the locations of high biodiversity in watersheds, compare aquatic biodiversity distributions among regions, and provide watershed-scale information useful for targeting conservation measures. The National Biological Service (USA) in cooperation with other Federal and State agencies developed geographic information system (GIS) methodology called Gap Analysis to identify the distribution of biodiversity over large spatial areas. To date, it has been used to address only terrestrial conservation needs. We are developing an aquatic version of the Gap Analysis in the Allegheny River drainage in western New York State to define the methodology and evaluate the feasibility of predicting biodiversity distribution at the watershed scale.
Our standardized stream reach accounting system is based on the U.S. Environmental Protection Agency Reach File 3 System. Each stream reach is classified into one of 18 habitat types for fish faunal predictions and one of 8 habitat types for invertebrate faunal predictions. Habitat types were defined using the following sets of physicochemical attributes: stream size (headwaters, large streams/small rivers, large rivers), physical habitat (dominated by natural geomorphological processes, moderately altered, and dominated by human structures and controls), water quality (suitable for life support, biologically stressful), gradient (steep, low slope) and riparian forest cover (closed canopy over channel, open channel). Stream size was determined from drainage area using the GIS. Physical habitat, reach gradient, and riparian forest cover were classified from topographic and land use maps. Physicochemical data from the U.S. Environmental Protection Agency STORET database provides a means to classify water quality. Using our habitat typing system, we predict that the highest fish diversity will be found in medium size streams with natural fluvial channels and good water quality, whereas the most reduced fish faunas will be found in large rivers with highly modified channels and poor water quality. For invertebrates, we predict that the greatest diversity (in terms of ecological function groups) will be in small and medium size streams with primarily a closed canopy, steep gradient, and good water quality.
Our GIS modeling effort succeeded in predicting the expected distribution of fish and invertebrate diversity at the watershed scale. Adequate biological and physicochemical data appear available and compatible with watershed-scale GIS programs. We also have extensive biological survey data that provides an independent means to testing the validity of our biodiversity predictions
Predicting barrier passage and habitat suitability for migratory fish species
No full textFish migrate to spawn, feed, seek refuge from predators, and escape harmful environmental conditions. The success of upstream migration is limited by the presence of barriers that can impede the passage of fish. We used a spatially explicit modeling strategy to examine the effects of barriers on passage for 21 native and non-native migratory fish species and the amount of suitable habitat blocked for each species. Spatially derived physical parameter estimates and literature based fish capabilities and tolerances were used to predict fish passage success and habitat suitability. Both the fish passage and habitat suitability models accurately predicted fish presence above barriers for most common, non-stocked species. The fish passage model predicted that barriers greater than or equal to 6 m block all migratory species. Chinook salmon (Oncorhynchus tshawytscha) was expected to be blocked the least. The habitat suitability model predicted that a shift from intact to highly degraded habitat has a greater impact on suitability for fish than a shift in gradient. Additionally, low gradient streams are likely to have higher diversity than high gradient streams. The fish passage and habitat suitability models were intended to be Fish migrate to spawn, feed, seek refuge from predators, and escape harmful environmental conditions. The success of upstream migration is limited by the presence of barriers that can impede the passage of fish. We used a spatially explicit modeling strategy to examine the effects of barriers on passage for 21 native and non-native migratory fish species and the amount of suitable habitat blocked for each species. Spatially derived physical parameter estimates and literature based fish capabilities and tolerances were used to predict fish passage success and habitat suitability. Both the fish passage and habitat suitability models accurately predicted fish presence above barriers for most common, non-stocked species. The fish passage model predicted that barriers greater than or equal to 6 m block all migratory species. Chinook salmon (Oncorhynchus tshawytscha) was expected to be blocked the least. The habitat suitability model predicted that a shift from intact to highly degraded habitat has a greater impact on suitability for fish than a shift in gradient. Additionally, low gradient streams are likely to have higher diversity than high gradient streams. The fish passage and habitat suitability models were intended to bePeer reviewe
Fish Community Support in Wetlands within Protected Embayments of Lake Ontario
No full textFish community data were collected to investigate the role of wetlands in supporting fish communities of protected embayments in Lake Ontario. Wetland and deeper, more open, littoral sites were sampled in five protected embayments using gill nets, fyke nets, minnow traps, and electrofishing gear during the summers of 2001 and 2002. Pooled gear data were used to analyze community composition, size frequency, and species richness. We found that even within protected embayments where community composition of both habitats is similar, wetlands support a community of fish different in species dominance and size structure than littoral embayment habitats. The abundance of young-of-year fish suggests that wetlands support fish populations by providing important nursery habitat. The similarity in fish community composition between wetland and littoral habitats indicates that wetlands remain important in supporting a subset of the embayment fish community. These results demonstrate that both wetlands and littoral areas in embayments are valuable and intensively utilized fish habitats that should receive special consideration in ecosystem management plans for the Great Lakes
PEER REVIEWER
No full text-PEER REVIEWER\ud
Deteksi Gen Phytoene Sinthase 1 (PSY1) dan Karoten Plasma Nutfah Jagung Lokal Sulawesi Selatan Untuk Seleksi Jagung Khusus Provitamin A\ud
(Juhriah, Baharuddin, Yunus Musa, Marcia B. Pabendon, dan Masniawati).\ud
J. Agrivigor 11(2):152-160, Januari ??? April 2012; ISSN 1412-2286
- …
