A healthy, happy Fish should be seen swimming calmly through the water upright with all their fins spread out. A common problem pond keepers meet is their Fish at the surface “gasping” for air. This is a sign of the Fish struggling with breathing. Unlike other Animals, Fish do not possess lungs instead they rely on gills for respiration/breathing. Usually, the simple act of them breathing is not very noticeable however when they are struggling them will expand their gill plates in and out and open and close their mouth almost reflecting that of “gasping”. The cause for this can be several things, firstly a lack of oxygen in the water column. If the water surface is not agitated enough the vital gas exchange of CO2 exiting the pond and oxygen entering can be affected causing a low level of oxygen. A simple fix to this is to cause surface agitation in the form of an air pump, fountain, waterfall etc. Another cause of the “gasping” can be nitrite poisoning; this is easily tested for with a simple pond water test kit. If nitrite is present this will heavily affect the Fish’s ability to absorb oxygen through their gills. A quick fix would be to carry out a series of partial water changes to bring the nitrite levels down, also adding beneficial bacteria products to your filter can aid in breaking down the nitrites. Ultimately investigating why nitrite is present in the first place is vital to avoid a recurrence.
Another cause of “gasping” can be a symptom of underlying parasite such as Gill Flukes which in severe cases can be such a strong infestation that it physically affects the gill’s ability to absorb oxygen.
