You will be surprised to know that there are significant categories of aquatic microbes that positively thrive in completely anoxic waters; indeed, they become inactive if any oxygen is present. These so-called ‘obligate anaerobes’ are thought to be descendants of some of the earliest life forms on our planet, and they play crucial roles in the cycling of carbon, sulphur and nitrogen in natural waters. For about a century now, certain strains of these microbes have been deliberately harnessed for the purposes of anaerobic wastewater treatment (see Chapter 8 ), which has recently come of age also as a source of low-carbon energy
Rivers and streams
The open water column is but one component of the stream habitat. Just as important are the bed sediments, or benthos, in which the majority of freshwater invertebrates live. These invertebrates are the principal food of many fish, and also of specialized birds such as dippers. Their abundance, diversity and condition are excellent indicators of the overall health of a river or stream. Just like most fish, invertebrates are highly sensitive to shortages of oxygen and to toxic effects of various pollutants.
The benthos is also important for offering a relatively safe haven in which fertilized fish eggs can be incubated until they hatch. Most noteworthy are the pods of eggs known as ‘redds’ which salmon and trout construct in gravelly areas of river bed, mainly in upland tributaries where flow is fast and the open structure of the gravels ensures lively exchange of oxygen-rich water with the overlying water column. The seasonal patterns of spawning, hatching and early development of young fish, or fry, are highly attuned to the annual changes in rainfall and runoff. Salmon which spawn in rivers spend most of their adult lives at sea, only returning to their native rivers to breed. By processes which are as yet poorly understood, salmon have an uncanny ability to identify not only the very river in which they were born, but also the very reach in which they emerged from a redd. It has long been assumed that some signals from water quality must guide the returning fish, though statistical analysis of the chemistry of adjoining rivers often reveals no demonstrable difference between them, so quite how such discernment works remains a mystery.
Lakes and wetlands
Interconnected as they are with rivers, it is no surprise to learn that much of the aquatic ecology of lakes resembles that of rivers. However, because they tend to be rather deeper than rivers, lakes offer important refuges for fish during the winter, when some rivers can freeze almost to the bed. Whereas, wetland is a body of water (perennial or seasonal) in which water depth is insufficient to preclude the growth of aquatic plants rooted in the benthos.
Knowledge is good and reading about rivers and streams, lakes and wetlakes is certainly better; however, in midst of all this information, you don’t have to forget about your regular water supply. There could be numerous reasons that you could need the help of your water supplier and to get these issues sorted out, feel free to reach them at Northumbrian Water Contact Number.