{"id":146,"date":"2021-02-24T18:48:00","date_gmt":"2021-02-24T18:48:00","guid":{"rendered":"https:\/\/www.fisheriesmanagement.org.uk\/?page_id=146"},"modified":"2026-02-24T18:59:50","modified_gmt":"2026-02-24T18:59:50","slug":"water-quality","status":"publish","type":"page","link":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/water-quality\/","title":{"rendered":"WATER QUALITY"},"content":{"rendered":"

WATER QUALITY SEE ALSO ENVIRONMENTAL FACTORS<\/strong><\/p>\n

Appropriate\u00a0 water quality is essential\u00a0 for all life within water holding areas, but what are the important characteristics\u00a0 \u00a0of good water quality, and how do these\u00a0 characteristics\u00a0 vary for the optimum levels\u00a0 of the different fish species;\u00a0 equally importantly.\u00a0 how do the characteristics\u00a0 \u00a0vary for\u00a0 the levels of\u00a0 survival and levels of fish\u00a0 development into specimens for those\u00a0 different\u00a0 species\u00a0 Whilst oxygen is an obvious example of an\u00a0 essential\u00a0 characteristic\u00a0 particularly during extreme weather conditions (e. g. very cold periods when a heavily stocked fishery is covered by ice , and and oxygen is unable to reach the lower levels of\u00a0 the water holding area.), but what are \u00a0the other\u00a0 \u00a0important but less obvious\u00a0 characteristics .Some anglers also have\u00a0 aquariums or\u00a0 Koi ponds and have the view that the water quality in a fishery should be managed in the same way as\u00a0 that in their\u00a0 ponds, which can be tightly managed and controlled; open waterways, with their inflows and\u00a0 bank\u00a0 erosion\u00a0 \u00a0 continually bringing\u00a0 in elements (e.g. traces of iron, magnesium. calcium\u00a0 sodium, etc) and compounds (e.g. ammonia) which will inevitably have some effects on the water quality, some of which may be good and beneficial whilst\u00a0 others having an\u00a0 \u00a0adverse effect on the fishery\u00a0 Small unmanaged garden ponds can quickly become no more than water on a bed of sludge with a\u00a0 limited degree of water above the sludge. this may involve complete emptying of the pond.\u00a0 Some\u00a0 However, in reality\u00a0 the larger fishery may hold millions of gallons of water whilst an aquariums or koi ponds will have only a few hundred\u00a0 gallons of water and use systems of filtration which would\u00a0 on major fisheries would be expensive if not impossible\u00a0 to replicate\u00a0 in fisheries. Conversely however , it would take considerable\u00a0 amounts of any element or compound to pollute the fishery.\u00a0 fisheries which may have have millions of gallons of water\u00a0 Management of\u00a0 the water quality is major\u00a0 challenge\u00a0 as effective management\u00a0 involves not only recording the different characteristics\u00a0 but\u00a0 also taking appropriate action to offset any problems. In larger fisheries do what you can with the environment around the fisheries to stop the erosion of water quality (e.g. manage\u00a0 dying tree leaves entering the fishing and increasing the levels of salt caused by the build up of leaf silt at the bed of the fishery; introduce adequate plant life to filter and oxygenate the water and substrate. on larger waters, eg. fisheries silt problems can be a major challenge; mechanical silt removal can help but can also be very expensive, silt reduction compounds are available but can be expensive and unproven. The water can be either aerated only\u00a0 or aerated\u00a0 and also filtered, meaning that a degree of silt, etc. is removed from the water.<\/span><\/p>\n

I have always been interested to know why for a period of time a certain species in a particular venue\u00a0 reach\u00a0 significant sizes and why they either retain these sizes\u00a0 for many, many years, or<\/strong> alternatively significantly decrease after either short or extended periods, without any fish deaths being seen or reported. .\u00a0 Why for example does a\u00a0 small water of less than 1 or 2 acres support carp over 20lbs.\u00a0 in weight and why do other waters never attain anything like these weights; or similarly\u00a0 why do\u00a0 some waters hold many roach over 2 or 3 lbs. or perch over 3 or 4 lbs,\u00a0 whilst others do not achieve anything like these weights.\u00a0 Adding additional fish stocks to any species will\u00a0 is\u00a0 no doubt be\u00a0 a major factor in\u00a0 this conundrum but there must be many other factors which affect this situation.<\/p>\n

To learn more and to assess the levels of consistency on our respective water measurement of important water quality factors were taken on a fortnightly basis for a period of 12 months<\/p>\n

There was close similarity on most measurements (e.g. temperature, oxygen levels, very small traces of ammonia and nitrites).<\/p>\n

There was, \u00a0however, \u00a0 an outlier Fir Tree Flash, which had high levels \u00a0of salinity, conductivity,\u00a0 suspended solids. The \u00a0Fir Tree Flash had been used as a site for official tipping \u00a0many years ago.though it \u00a0continued to produce tench between 3 and 4 lbs, with the odd\u00a0 larger fish, we were unsure as to whether the resident fish had built up resistance to the\u00a0 \u00a0high salt levels and \u00a0suspended salts and\u00a0 unsure as to how newly introduced fish would react to these high levels. No significant stocking took place in this water, although limited \u00a0smaller fish stocking has been used to test the water’s suitability to maintain and improve fish stocks.\u00a0 In the longer term the higher levels do not\u00a0 appear to show any adverse effects on the fishery. The Fir Tree Flash has very good water. \u00a0The clarity of the water may be important to the angler but it is not always a measure of salinity or conductivity; all the\u00a0 above fisheries vary in clarity at different times of the year or even different times of the month. \u00a0 The quality of Fisheries will never compete with the small ponds used for the development of koi carp and other expensive fish using filtration systems to maintain high levels being tightly controlled. This type of\u00a0 filtration\u00a0 system is replaced by the natural ecological\u00a0 processes in the fisheries,\u00a0 and the water quality will inevitably be of a much lower standard. Aeration is becoming increasingly used in commercial type fisheries to increase oxygen levels and generally improve water quality.<\/p>\n

Water is an excellent solvent, it is not surprising, therefore,\u00a0 that water qualities will be very different on different waters. If for example the water is sourced from inflows passing over limestone, then \u00a0it will probably be much harder\u00a0 and more\u00a0 acidic than\u00a0 inflows from a primarily agricultural setting.\u00a0 If there are no major inflows and outflows the water quality can be influenced\/improved\u00a0 by the addition of nutrients which can affect the softness or hardness of the water (e.g. crushed limestone to influence degree of hardness), Care is needed, however, in ensuring the correct levels of nutrients are introduced into any fishery at the right times.\u00a0 Regular checks on the water quality are an essential part of\u00a0 good fishery management. Water quality is particularly important if fish are transferred from one fishery (e.g. fish farm to a fishery). Although approval may be gained for\u00a0 the transfer,\u00a0 the difference between the water quality of the holding area and the fishery to which the fish stocks are being transferred can be critical particularly , if there are major difference in the levels of dissolved oxygen and ammonia. Ideally both waters should be checked for consistency before the transfer. Consider the comparison before transfer.\u00a0 We had one occasion on our waters where a transfer resulted in the loss of a significant number of fish probably as a result of\u00a0 our fishery having significantly\u00a0 lower levels of oxygen and higher levels of ammonia from the farm from which they were transferred<\/p>\n

Hardness and softness is measure, if there\u00a0 on a very simple scale of levels of calcium and magnesium\u00a0 mg\/l (I.e. mill.igrams per litre) in the water\/fishery\u00a0 and is primarily the levels of\u00a0 calcium and magnesium within\u00a0 the water structure.\u00a0 \u00a0There are no exact\u00a0 value requirements as to how\u00a0 soft or how hard\u00a0 a water body should be in the perfect fishery,\u00a0<\/strong>\u00a0 \u00a0but if the levels of calcium and magnesium are sometimes divided into the following ranges. The\u00a0 guide\u00a0 gives some indication of its value of its softness or hardness.\u00a0 The levels will\u00a0 affect the ability of the water to support life.<\/p>\n

0 – 75\u00a0 \u00a0 mg\/l\u00a0 \u00a0 \u00a0SOFT<\/p>\n

75-150\u00a0\u00a0 mg\/l\u00a0 \u00a0MODERATELY HARD<\/p>\n

150-300\u00a0 mg\/l\u00a0 \u00a0 HARD<\/p>\n

300+\u00a0 \u00a0 \u00a0 \u00a0 mg\/l\u00a0 \u00a0 \u00a0VERY HARD<\/p>\n

Comparisons of the softness\/hardness on your waters together with their respective fishery results can be helpful in managing your respective fisheries.<\/p>\n

As well as waters changing their characteristics (e.g. hardness\/softness, salts\u00a0 oxygen levels, etc.);\u00a0 changing\u00a0 with the qualities of the inflows\u00a0 that flow into them,\u00a0 \u00a0the water quality, particularly\u00a0 the levels of oxygen, carbon dioxide, will also be affected by air flows.\u00a0 which are constantly passing from the atmosphere into the fishery. The transfer of oxygen into the water is dictated by the air pressure and temperature, and to a lesser \u00a0extent by the levels \u00a0salts within the water. Almost all life aquatic life needs oxygen to survive, only certain bacteria, which use hydrogen and nitrogen as part of what is known as the nitrogen cycle can survive without oxygen. The nitrogen cycle is very important to life within the fisheries. As fish and plant deaths occur, and as uneaten bait and fish faeces build up then so too does the level of ammonia. Ammonia is toxic to fish, even at very small levels. Certain bacteria (Nitrosomanas and Nirobacter), break down the ammonia to nitrites and eventually to nitrates, which are non toxic to fish. There is, however, a limit as to how quickly the bacteria\u2019s can handle the ammonia, so measurement of the levels of ammonia is an important part of fishery management, particularly \u00a0in heavily stocked fisheries and at times when fish deaths become obvious (e.g. ice covered fisheries)<\/p>\n

As mentioned in the section on Environmental Factors the levels of oxygen are critical to all aquatic life, including fish life. The levels of oxygen being dictated being dictated by many many factors (I.e.inflows outflows, air temperature, air pressure, demand from all aquatic life,\u00a0 salt levels, etc..). Plant life is also a factor in the oxygen supply;\u00a0 aquatic plants creating more oxygen during the day by photosynthesis but using oxygen during the night ; this can cause problems early morning in the\u00a0 summer months.<\/p>\n

Many clubs and Associations are moving towards the use of aeration to add oxygen to the fishery; some use solar power others electric power. The movement of water\u00a0 does increase the oxygen level, but measure also the effects on conductivity and salt levels to ascertain if they are increased,<\/p>\n

Although water depth and aquatic plant life are not directly measurements of the water quality they are major factors in how fisheries can be\u00a0 maintained and developed.\u00a0 Having the right depth to sustain the respective species (e.g. deeper water for bream, shallower areas for spawning of all species) is part of a fishery management plan. The management of weed growth is another important issue that needs constant monitoring; (e.g. having the right balance between protection of the species from bird predation and the needs of the angler is not always easy to achieve). More detail of this type of information is included on the page on Environmental Issues.<\/p>\n

Silt\u00a0 levels build up over the years\u00a0 In some cases the silt levels may become a problem; reducing the depth of the fishery and reducing the quality of the fishery.\u00a0 Products are available to reduce silt levels but usually the earlier they applied the better. Monitor the effects of the application on a smaller water or reduced area to assess its effectiveness. Silt levels can be managed either manually, (e.g traps, manual , removal, sluices, etc)\u00a0 though this is a difficult\u00a0 task\u00a0 by the use of\u00a0 chalk, lime, specially supplied chemical agents.<\/p>\n

As Water Quality<\/strong> is the\u00a0 major factor in fish health; having the right equipment to measure the quality is essential. Some equipment can be very expensive, others may be no more than test strips (e.g. ammonia, nitrites, nitrates) but may give some indications of problems. Take measurements regularly and record them accurately to identify any problems and trends.\u00a0 See the page on environmental factors as the water environment and water quality are very closely related.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

WATER QUALITY SEE ALSO ENVIRONMENTAL FACTORS Appropriate\u00a0 water quality is essential\u00a0 for all life within water holding areas, but what are the important characteristics\u00a0 \u00a0of good water quality, and how do these\u00a0 characteristics\u00a0 vary for the optimum levels\u00a0 of the different fish species;\u00a0 equally importantly.\u00a0 how do the characteristics\u00a0 \u00a0vary for\u00a0 the levels of\u00a0 survival… Continue reading WATER QUALITY<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-146","page","type-page","status-publish","hentry","entry"],"_links":{"self":[{"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/pages\/146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/comments?post=146"}],"version-history":[{"count":47,"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/pages\/146\/revisions"}],"predecessor-version":[{"id":681,"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/pages\/146\/revisions\/681"}],"wp:attachment":[{"href":"https:\/\/www.fisheriesmanagement.org.uk\/index.php\/wp-json\/wp\/v2\/media?parent=146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}