Elevated Incidences of Antimicrobial Resistance and Multidrug Resistance in the Maumee River (Ohio, USA), a Major Tributary of Lake Erie

Maumee River, the major tributary in the western basin of Lake Erie, serves as one of major sources of freshwater in the area, supplying potable, recreational, and industrial water. In this study we collected water samples from four sites in the Maumee River Bay between 2016–2017 and E. coli was isolated, enumerated, and analyzed for antimicrobial resistance (AMR) and multidrug resistance (MDR). Strikingly, 95% of the total isolates were found to be resistant to at least one antibiotic. A very high resistance to the drugs cephalothin (95.3%), ampicillin (38.3%), tetracycline (8.8%), gentamicin (8.2%), ciprofloxacin (4.2%), cefoperazone (4%), and sulfamethoxazole (1.5%) was observed within isolates from all four sampling sites. Percentages of AMR and MDR was consistently very high in the summer and fall months, whereas it was observed to be lowest in the winter. A remarkably high number of the isolates were detected to be MDR—95% resistant to ≥1 antibiotic, 43% resistant to ≥2 antibiotics, 15% resistant to ≥3 antibiotics, 4.9% resistant to ≥4 antibiotic and 1.2% resistant to ≥5 antibiotics. This data will serve in better understanding the environmental occurrence and dissemination of AMR/MDR in the area and assist in improving and establishing control measures.

What happens in the darkness? Seasonal variations in tropical benthic fish assemblages

Studies of fish assemblages have demonstrated that the main channels of rivers contain ichthyofauna adapted to this environment. However, information regarding the effects of temporal and spatial variations on this ichthyofauna is scarce. Using data from benthic fish assemblages in a major tributary of the Amazon basin collected during two consecutive receding and two rising water seasons, we tested the hypothesis that there are marked variations in community composition between the receding and rising water seasons. An asymmetry in predictability was detected among samples from the receding and rising seasons. Predictability in terms of species composition was higher for receding than rising seasons. The continual disassembly and reassembly cycles (due to dispersal) of local communities across a spatially heterogeneous landscape could explain this difference. Depth and dissolved oxygen affected the distribution of some benthic fish species during the rising seasons. This study highlights the important contribution of marginal wetlands to the benthic ichthyofauna inhabiting the main channel of the Purus River, as well as other major Amazonian rivers.

Loaches of Homatula (Teleostei: Nemacheilidae) from the upper Salween River in Yunnan, China with description of three new species

Seven loaches of Homatula are distributed in a narrow geographical area between the upper Black River (or Song Da in Vietnam, that is a major tributary of the Red River, including the tributaries Lixian-jiang and Tengtiao-jiang in Yunnan, China) and the upper Salween River drainage (including tributaries of the Nu-jiang and Nanding-he, the latter is a major tributary of the Salween River in Yunnan, China). These seven species are distinguished from other Homatula by the combination of having the body densely-scaled, the lateral line complete, and a short adipose crest along the dorsal midline of the caudal peduncle that does not reach the posterior end of anal-fin base or does not extend beyond the middle of the anal-fin base. Based on a comparison with the described species of the densely-scaled group of Homatula, we can confirm that the specimens collected from the Nu-jiang drainage in western Yunnan are different from known species and are described herein as Homatula anteridorsalis sp. nov., Homatula cryptoclathrata sp. nov., and Homatula nigra sp. nov.

Limnological effects of a large Amazonian run-of-river dam on the main river and drowned tributary valleys

Run-of-river dams are often considered to have lower environmental impacts than storage dams due to their smaller reservoirs and low potential for flow alteration. However, this has been questioned for projects recently built on large rivers around the world. Two of the world’s largest run-of-river dams—Santo Antônio and Jirau—were recently constructed on the Madeira River, a major tributary to the Amazon River in Brazil. Here we evaluate the effects of the creation of the Santo Antônio dam on the water chemistry and thermal structure of the Madeira River mainstem and back-flooded valleys of tributaries within the reservoir inundated area. In contrast to the mainstem river, some back-flooded tributaries periodically developed thermal stratification, which is associated with higher water residence times. Additionally, biochemical oxygen demand, partial pressure of CO2, and organic carbon all increased in the tributary valleys inundated by the reservoir, possibly due to increased input of allochthonous organic matter and its subsequent mineralization upon back-flooding—a common feature of newly flooded impoundments. The mainstem did not show detectable dam-related changes in water chemistry and thermal structure. Although the majority of the reservoir area maintained riverine conditions, the lateral valleys formed upon back-flooding—corresponding to ~30% of the Santo Antônio reservoir area—developed lake-like conditions akin to a typical reservoir of a storage dam.

River Vishav Contribution to 2014 Devastating Floods of Kashmir (India)

Floods cannot be absolutely controlled but can be managed to reduce the losses. The changing climate is a major cause of the increasing trends in the erratic and heavy rainfall events causing floods. The rains those lashed out during the first week of Septemeber-2014 in Kashmir Valley resulting in a devastating flood is one of the examples of such hazards. Many attempts have been made by different agencies and the people to ascertain the cause of this devastating flood. Most of these studies focus on the River Jhelum’s main course and do not pay much attention to the role of its tributaries in the said event. The present study is an attempt to analyse the role of the most hazardous tributary of the River Jhelum, known as Vishav River in the horrible catastrophe. River Vishav is a major tributary of the river Jhelum and contributes to nearly one-fifth of its discharge. On basis of the information collected and the survey conducted after the floods, it is believed that this tributary of river Jhelum played a major role in the 2014- devastating floods. The present study highlights the present status of the river Vishav, its behaviour, its role in 2014 floods and flood mitigation measures in the Vishav basin.

Managing Centrarchid Fisheries in Rivers and Streams

<em>Abstract.</em>—The Choctaw Bass <em> Micropterus cf. punctulatus </em>is an undescribed black bass found in coastal river systems of northwest Florida and southern Alabama. The Choctaw Bass is morphologically similar to the Spotted Bass <em> M. punctulatus</em>. Prior to this study, there was no published life history information specific to this black bass. The need to address these information gaps was further influenced by the popularity of black bass fishing and potential statewide black bass regulation changes in Florida. Our research examined relative abundance, age, mortality, growth, and diet of Choctaw Bass collected from the Choctawhatchee River, Florida and Holmes Creek, a major tributary of the Choctawhatchee River in fall 2012 and 2013. Choctaw Bass were compared to sympatric Largemouth Bass <em> M. salmoides </em>× Florida Bass <em> M. floridanus </em>intergrades. Relative abundance was lower for Choctaw Bass than Largemouth Bass in both the Choctawhatchee River and Holmes Creek. The oldest Choctaw Bass from the Choctawhatchee River was age-5 and the oldest Choctaw Bass from Holmes Creek was age-11. Total instantaneous mortality of Choctaw Bass was statistically similar between the study areas. Total instantaneous mortality for Choctaw Bass from Holmes Creek was also similar to sympatric Largemouth Bass. Growth differed for Choctawhatchee River and Holmes Creek Choctaw Bass. Diets of Choctaw Bass collected from the Choctawhatchee River consisted primarily of fish while diets of Choctaw Bass and Largemouth Bass collected from Holmes Creek consisted primarily of crayfish. The observed restricted distribution, limited abundance relative to Largemouth Bass, limited number of Choctaw Bass collected greater than 406 mm TL, and the lack of Choctaw Bass older than age-5 in the Choctawhatchee River led to the recommendation that Choctaw Bass be managed separately from Largemouth Bass.