Heavy metal contamination in two commercial fish species of a trans-Himalayan freshwater ecosystem.

Toxic metals have disturbed the quality of freshwater ecosystems worldwide. The concentration of heavy metals was investigated in liver, gills and muscle tissues of Schizothorax niger and Cyprinus carpio captured from river Jhelum of Kashmir Himalaya. The heavy metals displayed a wide range of disparity in studied tissues, seasons, sites and species. Cu2+ exhibited the highest concentration (279.6 µg/kg) in the liver tissues of S. niger in autumn at site 2 and the lowest (53.1 µg/kg) in the gill tissues in winter at site 1. In C. carpio, the Cu2+ was recorded highest (309.4 µg/kg) in the liver tissues in autumn at site 2. The concentration of Zn2+ was found highest (575.7 µg/kg) in the liver tissues at site 2 and the lowest (65.8 µg/kg) was recorded in the muscle tissues in autumn at site 1. Zn2+ was recorded highest (416.6 µg/kg) in the liver tissues in autumn at site 3 and lowest (51.5 µg/kg) in the gills of C. carpio during winter at site 1 (control). The concentration of Pb2+ (14.42 µg/kg) and Fe2+ (323.9 µg/kg) was observed in the liver tissue and gills of S. niger at site 3. Similar levels of Pb2+ and Fe2+ were recorded in the tissues of C. carpio at different sites. Four-way ANOVA (four way) indicated a statistically significant variation (p ≤ 0.05) in heavy metals with the sites, seasons, species and organs. The study emphasises the utmost need to monitor the level of heavy metals in S. niger on a regular basis as this native fish species is showing a continuous decline in the freshwater ecosystems of Kashmir Valley.

First record of protozoan parasites in cyprinid fish, Schizothorax niger Heckel, 1838 from Dal lake in Kashmir Himalayas with study on their pathogenesis.

Trichodina heterodentata Duncan, 1977 and Ichthyophthirius multifiliis Fouquet, 1876 obtained from gills during a parasitological survey conducted for the protozoan parasitic fauna of Schizothorax niger a snow trout in Dal Lake, Kashmir, India during the period October 2013 and March 2015. Thirty out of 180 fish were found infected with protozoan parasites. During the study of their pathogenecity the most common deteriorating signs observed in gill tissue were necrosis, hypertrophy, hyperplasia and fusion of secondary lamellae. Prevalence of infection was found to be 16.66%. This is the first record of the protozoan fauna of the schizothoracines from Kashmir valley, India.

Ceratophyllum demersum-An accretion biotool for heavy metal remediation.

Freshwater habitats are under serious threat due to the diverse pressures of development and restoration of these ecosystems is an important challenge in the present era. With a number of scientifically advanced methods available for restoration of these systems, phytoremediation finds its unique space as an ecologically sustainable technique. In this paper, a case study of Certophyllum demersum as a tool of heavy metal remediation in Dal lake, a natural freshwater system in Kashmir, India is presented. At all concentrations (2 ppm, 4 ppm, 6 ppm) the metal accumulation efficiency of C. demersum is of the order of Co2+ > Cd2+ > Mn2+ followed by other metals. The carbohydrate- protein plot reveals positive correlation (0.696) with the heavy metal uptake while the lipid-protein plot overall shows a weak correlation (0.296) and the carbohydrate-lipid plot shows an insignificant correlation (0.019). The results of the present study revealed attenuation of protein levels at low doses which lowered with increased heavy metal concentrations. Further, the overall lipid and carbohydrate content of the cultured C. demersum displayed a general decline with a rise in the concentration of heavy metals The overall study indicates the efficiency of C. demersum to adapt in polluted conditions and its potential to remove heavy metals for sustainable restoration of the degraded aquatic systems.

Vulnerability of municipal solid waste: An emerging threat to aquatic ecosystems.

Dumping waste materials into aquatic ecosystems leads to pollution, which directly and indirectly poses a danger to all life forms. Currently, huge quantities of wastes are generated at a global scale with varying constituents, including organic fractions, emerging contaminants and toxic metals. These wastes release concentrated contaminants (leachates), which are lethal for all ecosystems around the globe because they contain varying concentrations of chemical constituents with BOD5 and COD in the order of 2 × 104-2.7 × 104 mg/L, and 3.4 × 104-3.8 × 104 mg/L, respectively. Herein, in-depth knowledge of municipal solid waste dumping into the aquatic ecosystems, changes in physicochemical characteristics, availability of in-/organic contaminants, and long-term unhealthy effects are presented. Moreover, an attempt has been made here to summarize the facts related to identifying the deadly impacts of waste on different ecosystem components. The unresolved challenges of municipal waste management are emphasized, which will help employ suitable waste management techniques and technologies to conserve the everlasting freshwater resources on earth.

A report on the incidence of Trichodina heterodentata from fishes of Jammu, J&K India.

The present study was aimed at screening for the presence of protozoan's among Cyprinid fishes collected from various fish ponds and farms in Jammu division of Jammu and Kashmir (J and K) state. Out of 75 fishes collected from local water bodies of Jammu division, only 35, (49.6 %) were infested with Trichodina. Trichodina infestations were studied in the period from November to February. In light infestation Trichodina was usually present on gills, fins and skin of apparently healthy fish. Clinical signs of Trichodiniasis appeared on fish with heavy infections and in presence of one or more stress factors including, rough handling during transportation from ponds, over crowdedness, malnutrition, high concentration of free ammonia and low oxygen concentration. Clinical signs of Trichodiniasis in fish such as sluggish movement, loss of appetite, black colouration, necrosis and ulcer on different parts of the body, detached scales and excessive accumulation of mucous in gill pouches were also observed.