Category: Costal and marine | Freshwater | Management

Aquapollution and its impact on aquatic environment

Aqua Pollution is said to be the oldest issue for the world but the whole world somehow manage to talk about it again and again. Sometimes there come some suggestions but it’s the ultimate truth that aqua pollution didn’t, doesn’t and will not stop because of the continuous movement of human civilization. Several literatures has already set light on the identified point and non-point sources that cause aqua pollution. But some sources of aqua pollution raise the question that is it possible to cause pollution in such a way?

Radioactivity of nuclear sources come to this category. The nuclear fuel reprocessing plants proves that how frustrating the impact of radioactivity on aquatic environment was. Even the normal operation of nuclear power and thorium and the use of radioactive in industrial, medical, and scientific processes are marked out sources. Mining is enhancing this process. Rainwater leaches sulphur acid mine drainage and hit action of rainwater on piles of mining waste transfer pollution to freshwater supplies. In the case of gold mining, cyanide is intentionally poured on piles of mined rock. Some of the cyanide ultimately finds its way into nearby water. Huge pools of mining waste slurry are often stored behind containment dams. If a dam leaks or bursts, water pollution is guaranteed. Both the nuclear pollution and mining cause another secondary impact is called “thermal pollution”. Volcanic eruption and global warming are some other factors that control thermal pollution. Because of thermal pollution the warmer water also causes them to increase their respiration rates and consume oxygen faster. Pollutants which are dump in water of come with water during food intake increase the biological oxygen demand(BOD). Modification of the brachial cells, histological changes of the gills are caused by the pollutants.

Radio active waste cause genetically defects in fish species. Scientists explained that increasing sea-surface temperatures are associated with the spread of molluscan pathogen in the ocean. Industrial thermal pollution is a problem for our waterways—fish and other organisms adapted to a particular temperature range can be killed from thermal shock, and the extra heat may disrupt spawning or kill young fish.
There are effects of mining on cell membrane of algae, leading to a penetration of mining pollutants to cell and to the cellular fluid. The effect of toxins generated to next algae after every reproduction. Mercury is a pollutant absorbed directly in a food cycle of aquatic organisms where as a tertiary consumer, fish get mercury toxicity from producer or primary consumers or secondary consumers. Zooplankton eat the toxic algae and begin passing the toxins up the food chain, affecting edibles like clams, and way up to seabirds, marine mammals, and humans. The result can be illness and sometimes death. This decrease the quality of fish as human food. Sheal, Sea-cow, dolphins and other aquatic mammals stores toxins permanently in their body fat, which is disastrous for other aquatic animals. Bleaching agents use in metal purging have hormone-disrupting character on fish such as egg-growing male fish. More generally, the effects of hormone-disrupting chemicals include interrupted sexual development; thyroid system disorders; inability to breed; reduced immune response; and abnormal mating and parenting behavior. Deformed fish and other aquatic life occurs because of discharging dioxins. Fluoride poisoning affects the “skeletal fluorosis”. Benzene causes redness, burns and blisters on skin.

Nutrient pollution caused by forest destruction is a matter to be thought. When forests are clear cut the rot systems that previously held soil in place die and sediment is free to run of into nearby streams, rivers, and lakes. It increases the level of “nitrates and phosphate” mainly and moves towards nutrient type of pollution. Overgrowths of toxic algae result in “harmful algal blooms,” which are referred to as “red tides” or “brown tides.” Nutrient pollution can trigger unusual outbreaks of fish diseases and millions of marine fish can be killed from this out break.

Volcanic eruption and explosure during mining also cause “Sound pollution” which is also disastrous to aquatic organisms as well as human. Frequent or chronic exposure to both high- and low-intensity sounds may cause stress on all higher forms of marine life, potentially affecting growth, reproduction, and ability to resist disease. Powerful sonar systems operating at certain frequencies have been implicated in whale beaching and may cause damage to aquatic mammals'(dolphin, porpoises, seal) sound-sensitive internal structures, causing internal bleeding and even death.

It is true that when you have to fight against something you should know who your enemy is. The discussed sources of aqua pollution is not like you never heard. But the problem is only few of us just pay slight attention to them. I don’t know if it will be possible to make effective suggestion against these causes, but to do anything, first of all, we have to know about the unusual sources and their effect on aquatic environment.

References:

  • American Public Health Association. 1938. Standard methods for the examination of water and sewage. Amer. Pub. Health Assoc. New York. pp. 309.
  • Barbour,M.T.J. Gerritsen, B.D. Snyder, and J.b. Stribiling, 1999. “Rapid bio-assessment Protocols for Use in Streams and Wadeasble Rivers: Periphyton, Benthic Macro invertebrates and Fish Second Edition. EPA 841-B-99-002
  • Bliss, Chester I. 1935. The calculation of the dosage mortality curve. Ann. App. Biology, pp 134-167.
  • Chessman, A.B. and Bruce. 2003. A Scoring System for Macro- invertebrate (Ater Bugs) in Australian rivers. Monitoring River Health Initiative Technical Report no. 31, Commonwealth of Australia, department of the environment Heritage, Canberra. ISBN. 0642548978
  • Copeland, C. 1998 “Storm water Permits: Status of EPA’s Regulatory Program.” United States congressional Research Service, Washington, DC. CRS Report No. 97-290 ENR.
  • ESCAP,1988. Coastal Environment Management Plan for Bangladesh. Vol. 2. Bangkok, Thailand. p.149.
  • IUCN, 1999. Towards Sustainable Development: Fisheries Resources of Bangladesh. A background paper prepared for nation conservation strategy of Bangladesh (NCS), Bangladesh Agricultural Research Council (BRAC), Dhaka, p. 96
  • Nuruzzaman, A.K.M. 1990. Effect of Environmental Modification on Riverine Fisheries in Bangladesh, BRAC, Dhaka, p. 12.
  • Rounsefell, G.A and W. H. Everhart. 1953. Fishery Science its methods and application. John Willy and Sons. New York. pp. 211-225.

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Research Student, Department of Fisheries, University of Rajshahi, Rajshahi-6205, Bangladesh. More...

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