Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Puerto Rico ◽  
Freshwater Fish ◽  
Water Use ◽  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Physical Habitat ◽  
Resource Exploitation ◽  
Ecological Processes ◽  
Tropical Island

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Generalized Additive Models ◽  
Sampling Site ◽  
Monitoring Program ◽  
Additive Models ◽  
Species Lists ◽  
Freshwater Habitats ◽  
Eastern Mosquitofish

<i>Abstract.</i>—We document a simple electrofishing-only monitoring program for assessing fish assemblages across large spatial extents. First, we demonstrate the justification for using only electrofishing for the monitoring. Second, we demonstrate the usefulness of having a well-designed surveillance-monitoring program in place to demonstrate the effect of landscape disturbances. Implementing electrofishing alone means that multiple sites can be sampled in a single day and there is no need to return to clear nets or traps within a sampling site. Whereas electrofishing alone does not return full species lists within sampled sites, we demonstrate that when data are aggregated up to the watershed or catchment extent, more than 90% of species are included. Analyses that do not require a census of species, such as bioassessment of river health can be readily carried out using electrofishing data. The Murray–Darling basin, Australia, was sampled with the recommended large-extent electrofishing program between 2004 and 2012, a period that saw the region subjected to large-scale variations in river flow levels spatially and temporally. We fit generalized additive models to the electrofishing data in conjunction with river flow data to document large-extent relationships between fish species occurrence and relative flow levels for the previous 3 d, 3 months, or 3 years. We found that several small-bodied species, Eastern Mosquitofish <i>Gambusia holbrooki</i>, Flathead Gudgeon <i>Philypnodon grandiceps</i>, and Australian Smelt <i>Retropinna semoni</i>, were more likely to be collected when conditions were drier in the past 3 d to 3 months, whereas common medium and large-bodied species were less likely to be collected when flow was lower over the previous 3 months to 3 years.

Estimated water use in Puerto Rico, 1980

1983 ◽  
Author(s):  
Fernando Gómez-Gómez ◽  
Rafael Dacosta ◽  
Miguel Orona
Keyword(s):  
Puerto Rico ◽  
Water Use

Performance of a pool-and-weir fish pass for small bottom-dwelling freshwater fish species in a regulated lowland river

2007 ◽  
Vol 57 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Evelien Maerten ◽  
Marcel Eens ◽  
Guy Knaepkens
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Fish Assemblages ◽  
Regulated River ◽  
Lowland River ◽  
Stone Loach ◽  
Spined Loach ◽  
Freshwater Fish Species ◽  
Cottus Gobio ◽  
Fish Pass

AbstractAlthough small benthic freshwater fish species are an important biological component of fish assemblages and free instream movement is indispensable for their survival, they are often neglected in fish pass performance studies. In this study, a capture-mark-recapture approach was used to assess whether small bottom-dwelling species, including gudgeon (Gobio gobio), stone loach (Barbatula barbatula), spined loach (Cobitis taenia) and bullhead (Cottus gobio), were able to cross a pool-and-weir fish pass in a regulated lowland river. Some tagged individuals of stone loach (18%), gudgeon (7%) and spined loach (2%) managed to successfully ascend the fish pass under study, despite the fact that water velocity levels in the different overflows of the facility (between 0.55-1.22 m/s) exceeded the critical swimming speed of all three species. Although this suggests that a pool-and-weir fish pass is a able to facilitate upstream movement of some small benthic species in a regulated river, more detailed research incorporating advanced tagging and retrieving techniques is necessary.

scholarly journals MEDICAL AND ENVIRONMENTAL ASPECTS OF THE DEGRADATION OF THE PERMAFROST ZONE: PROBLEM OF PALEOVIRAL CONTAMINATION

2019 ◽  
Vol 96 (8) ◽  
pp. 706-711
Author(s):  
Leonid I. Elpiner ◽  
A. V. Dzyuba
Keyword(s):  
Surface Water ◽  
Groundwater Contamination ◽  
Water Use ◽  
Large Scale ◽  
Permafrost Zone ◽  
Environmental Aspects ◽  
Drinking Purposes

We present the concept of a possible global viral infestation associated with the processes of permafrost melting and probability of groundwater contamination with paleoviruses. The most realistic mechanism of the development of this process is considered, as well as possible ways of forming of a new epidemic situation, depending on characteristics of groundwater and surface water use for drinking purposes by the population of the permafrost zone (permafrost). The necessity of in-depth development of large-scale multi-disciplinary researches in order to clarify the pathogenetic significance of paleoviruses in the permafrost zone and assess the need of the development of the composition and the nature of the complex environmental and anti-epidemic measures is substantiated.

scholarly journals Thermodynamics, maximum power, and the dynamics of preferential river flow structures on continents

2012 ◽  
Vol 9 (6) ◽  
pp. 7317-7378 ◽  
Author(s):  
A. Kleidon ◽  
E. Zehe ◽  
U. Ehret ◽  
U. Scherer
Keyword(s):  
Free Energy ◽  
Large Scale ◽  
Scaling Laws ◽  
Preferential Flow ◽  
River Flow ◽  
Thermodynamic Description ◽  
Minimum Energy ◽  
Flow Structures ◽  
Drainage Basins ◽  
Drainage Systems

Abstract. The organization of drainage basins shows some reproducible phenomena, as exemplified by self-similar fractal river network structures and typical scaling laws, and these have been related to energetic optimization principles, such as minimization of stream power, minimum energy expenditure or maximum "access". Here we describe the organization and dynamics of drainage systems using thermodynamics, focusing on the generation, dissipation and transfer of free energy associated with river flow and sediment transport. We argue that the organization of drainage basins reflects the fundamental tendency of natural systems to deplete driving gradients as fast as possible through the maximization of free energy generation, thereby accelerating the dynamics of the system. This effectively results in the maximization of sediment export to deplete topographic gradients as fast as possible and potentially involves large-scale feedbacks to continental uplift. We illustrate this thermodynamic description with a set of three highly simplified models related to water and sediment flow and describe the mechanisms and feedbacks involved in the evolution and dynamics of the associated structures. We close by discussing how this thermodynamic perspective is consistent with previous approaches and the implications that such a thermodynamic description has for the understanding and prediction of sub-grid scale organization of drainage systems and preferential flow structures in general.

scholarly journals Testing hypotheses of diversification in Panamanian frogs and freshwater fishes using hierarchical approximate Bayesian computation with model averaging

2018 ◽  
Author(s):  
Justin C Bagley ◽  
Michael J Hickerson ◽  
Jerald B Johnson
Keyword(s):  
Freshwater Fish ◽  
Dna Sequences ◽  
Approximate Bayesian Computation ◽  
Bayes Factor ◽  
Fish Assemblages ◽  
Model Averaging ◽  
External Information ◽  
Bayesian Computation ◽  
Genetic Structuring ◽  
Approximate Bayesian

Most Neotropical frog and freshwater fish species sampled to date show phylogeographic breaks along the Pacific coast of the Isthmus of Panama, with lineages in Costa Rica and western Panama isolated from central Panama. We examine temporal patterns of diversification of taxa across this ‘western Panama isthmus’ (WPI) break to test hypotheses about the origin of species geographical distributions and genetic structuring in this region. We tested for synchronous diversification of four codistributed frog taxon-pairs and three fish taxon-pairs sharing the WPI break using hierarchical approximate Bayesian computation with model averaging based on mitochondrial DNA sequences. We also estimated lineage divergence times using full-Bayesian models. Several of our results supported synchronous divergences within the frog and freshwater fish assemblages; however, Bayes factor support was equivocal for or against synchronous or asynchronous diversification. Nevertheless, we infer that frog populations were likely isolated by one or multiple Pliocene–Pleistocene events more recently than predicted by previous models, while fish genetic diversity was structured by Pleistocene events. By integrating our results with external information from geology and elevational sea level modeling, we discuss the implications of our findings for understanding the biogeographical scenario of the diversification of Panamanian frogs and fishes. Consistent with the ‘Bermingham/Martin model’ (Mol. Ecol. 1998, 7: 499-517), we conclude that the regional fish assemblage was fractured by processes shaping isthmian landscapes during the Pleistocene glaciations, including drainage basin isolation during lowered sea levels.

scholarly journals Water Use by Flooded Rice in Puerto Rico

1969 ◽  
Vol 66 (3) ◽  
pp. 181-187
Author(s):  
Servando Silva ◽  
José Vicente-Chandler
Keyword(s):  
Puerto Rico ◽  
Water Use ◽  
Climatic Changes ◽  
Pan Evaporation ◽  
Flooded Rice ◽  
Evaporation Losses ◽  
The Relationship

Evapotranspiration with flooded, well-established rice averaged 0.61 cm/day, with a range from 0.31 to 0.84 cm/day. These variations resulted largely from climatic changes since they were closely related to evaporation losses from an open pan. The equation Y = 0.2691 + 0.4696 X (r = 0.97**) describes the relationship between evapotranspiration with rice and open pan evaporation, which averaged 0.55 cm/day during the experiment. Percolation losses in Toa soil (Mollisol) averaged only 0.20 mm/day after the first 2 weeks of flooding.

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