Search results for “Fishes”

The Adverse Effects of Underwater Sound upon Fishes and Invertebrates

Underwater sound is very important to most fishes and invertebrates. Underwater sounds from both natural and human sources can have adverse effects upon aquatic animals, and especially fishes, and invertebrates. It is important to examine the effects of sound upon them, and especially the effects of sounds derived from human sources (anthropogenic sounds). It may be possible to introduce protective regulations to reduce their effects. Fishes and invertebrates can detect underwater sounds, and they use sound to obtain key information about the environment around them. They can also make sounds themselves, especially during their spawning. Sounds travel rapidly over great distances in water and can provide detailed information to these animals on the presence of prey, predators, and related species, while the overall acoustic scene provides them with key information about their environment. Anthropogenic sounds can be very harmful, and it is therefore important to deal with them. A succession of reports and scientific papers have emphasised the risks to these animals from exposure to man-made sounds or noise and will be mentioned in this paper, which also deals with the Criteria and Metrics for assessing the effects of underwater sound on fishes and invertebrates.

RETRACTED: The Impact of Underwater Sound on Aquatic Animals – And Especially Fishes

This article has been retracted on 30 May 2023. VIEW THE RETRACTION NOTICE (https://doi.org/10.14302/issn.2643-0282.imsj-25-5851) Underwater sounds from human sources can have detrimental effects upon aquatic animals, including fishes, and currently such sounds are very common. It is important to examine such anthropogenic sounds and their effects upon aquatic animals, so that it is possible to introduce protective regulations. Fishes and other aquatic animals can detect underwater sounds and use them to obtain key information about the environment around them. Sounds travel rapidly over great distances in water and can provide detailed information on the presence of prey, predators, and related fishes, while the overall acoustic scene provides the fishes with key information about their environment. Although some of the background noise is generated by natural sources, including the precipitation of rain and snow, and wind and waves, many underwater sounds now come from anthropogenic sources, often termed “noise”. Some of these human-made sounds can kill or injure fishes and other aquatic animals, also impairing their hearing, and altering their behavior. There is a need for more work on the impact of human-made underwater noise upon the fitness of aquatic animals. This paper considers the gaps in information that must be resolved. The effects that need to be considered include death and injuries, physiological effects, and changes in behavior.

Retraction Note: The Impact of Underwater Sound on Aquatic Animals – And Especially Fishes

Diversity and Similarity of Flatfishes (Order- Pleuronectiformes) in Mon State, Myanmar

The samples of flatfishes were collected along the Mon State from July to December 2017 including Mawlamyine, Kyaikkhami, Setse, Zee-Phyu-Thaung Belugyun island, Paung and Thaton. The total 21 species of flatfishes were recorded in Mon State. Moreover, the relative abundance, diversity and similarity were conducted using Simpson Index, Shannon index and Jacquard’s index etc. According to the present study, the Cynoglossidae was the most dominant family and the most dominant species was Cynoglossusarelfor the present study. The relative abundance of Mawlamyine and November was relatively the highest. Furthermore, Mawlamyine was the highest diversity and Thaton was the lowest diversity. The JI value between Mawlamyine and Paung is the highest while it is the lowest between Setse and Thaton. Likewise, the JI value between August and September and the value between September and November are the same as well as the highest while it is the lowest for the comparison between July and August. The present study also expects to become a basic informational providing data for further observing (in Academic) on Order Pleuronectiformes (flatfishes) along the Mon State.

Adopting a Wider Approach for Fisheries Management

Many marine and freshwater fisheries are now in a very poor state, and many fish stocks are close to collapse. There is a need to manage fisheries more carefully, especially since fishing can affect other aspects of the environment. It is also important to reduce the adverse effects of climate changes upon the marine and freshwater environments, fishes, and other animals, and the need to manage other human activities taking place in the sea, to improve the marine environment and protect the wildlife and the fishing activities. Marine pollution, includes human waste materials, chemicals and plastics, and there is also noise and substrate vibration, from industrial and other activities that may affect both the abundance and quality of fishes and other marine animals. This paper deals with fisheries management, and environmental protection, and concludes that fishermen, fisheries scientists, fisheries managers and environmental interests must work closely together, if fishes are to be adequately protected, and fisheries are to be better managed. It describes current systems of management. It especially draws attention to the importance of moving towards an ecosystem-based approach to fisheries management. Such an approach aims to manage all those human activities that have an impact upon the marine environment and its life forms.

Prevalence and Factors Associated with Under Nutrition among Children Aged 6 to 59 Months in Ngoma District, Rwanda

In Rwanda, 38% children aged 6-59 months are stunted. In Ngoma District, stunting rate is estimated at 41% among the children aged below 5 years. The study objective was to evaluate the prevalence and factors contributing to under nutrition among children aged 6- 59 months in Ngoma District. Cluster sampling was used to determine the study participants for each sector within 14 sectors by considering the sample size of 442. The WHO Anthro software version 3.2.2 was used to determine the nutritional status of the children. SPSS version 24 was used for analysis. Of 442 children participated in the study 50.9% of them were females, 24.4% were aged 15-23 months and the majority of children (89.8%) born with normal birth weight. Study findings revealed that the prevalence of under nutrition was 33.7% for stunting, 3.6% for wasting and 6.6% underweighted. Poor sanitation facility (AOR: 4.1, 95%CI: 1.83-9.3, p=0.001), poor diet (AOR: 1.9, 95%CI: 1.18-3, p=0.008) were significantly associated with stunting. Factors such as lack of hand-washing facilities (AOR: 2.5, 95% CI: 1.013-6.3, p=0.047), not eat vegetables (AOR: 4.4, 95%CI: 1.7-10.96, p=0.001), and not eat fishes (AOR: 4.1, 95%CI: 1.6-10.6, p=0.003) were associated with wasting. Short breastfeeding duration (AOR: 4.5, 95%CI: 2.9-7.2, p=0.001), not eat vegetables (AOR: 1.9; 95%CI: 1.1-3.05, p=0.008), and not eat eggs (AOR: 2, 95%CI: 1.3-2.9, p=0.001) were associated with underweight. Poor families with under-five children need continuous support that will assist them to improve nutritional status of their children.

Behavioral Response and Acute Toxicity of Fingerlings of African Cat Fish, Clarias Gariepinus Exposed to Paraquat Dichloride

This study evaluated the behavioural response and toxicity of paraquat dichloride to fingerlings of Clariasgariepinus. The fishes were acclimatized for 14 days and exposed to sublethal concentration of 0.00 ppm, 16.56 ppm, 22.08 ppm, 27.60 ppm, 33.12 ppm and 38.64 ppm. A 24 hours’ renewal bioassay was adopted in this study. Results showed that the fishes exhibited change in swimming, opercular movement, body pigmentation, surfacing and air gulping. Mortality rate increased significantly at p<0.05 as the concentration of the toxicant increased as well as the exposure period. LC50 values at 24, 48, 72 and 96 were 59.95, 47.59, 38.12 and 26.18ppm, respectively. Based on the results, Paraquat dichloride users need to discard the remains of empty cans properly to avoid contamination. Also there is need to exercise caution when using paraquat dichloride based herbicides in agricultural fields close to surface water resources.