During warmer months, algae can quickly build up on the various natural ponds around the Deer Centre, potentially suppressing the growth and maintenance of more valuable aquatic plans used by species as cover, for nesting materials, food or any other purpose. Animals and food items can be caught in thicker algae and dead plants which have lost out in competition with the algae for sunlight, oxygen and other essential requirements. Food caught up in algae can quickly spoil and may hinder water quality if not removed regularly. Excessive levels of algae do not lend well to enclosure aesthetics, which can lead to some visitors assuming poor enclosure upkeep and neglect. 

For these reasons, most of the algae and any dead vegetation build up on ponds is removed by keepers on a weekly basis during spring and summer.

In the video to the right, I am shown clearing weeds, dead reeds and algae from the otter pond in one of the first cleans of the year, on 21 April 2016. I can be seen throwing cleared algae and plants onto the bankings of the pond, where it is left for two days to allow aquatic invertebrates to return to the pond and provide foraging opportunities for the otters with live invertebrate prey - replicating a natural behaviour. 

I work on a free-contact basis with the otters, and they are not held in another section of the enclosure whilst cleaning such as this is ongoing. This has been approved through risk assessments compiled since the otters arrived in the collection in 2009.

Pond cleaning also proves to be a social enrichment activity for the otters, who interact both with me whilst the pond is being cleaned and with each other in play, due to the excitement the activity generates in them. 

To maintain the quality of drinking water, all enclosure water troughs are checked daily and cleaned either on a daily (otters, wildcats and lynx) or monthly (all other species) basis at the Deer Centre. The otters dip food in their water bowl at feed times, whilst the lynx and wildcats commonly defecate in their bowls - hence all three are cleaned and, in the case of the lynx and wildcat bowls, disinfected with small quantities of water-diluted Virkon S on a daily basis. 

All other troughs are larger, used only for drinking, and are cleaned monthly whenever possible. Cleaning the troughs of many of our deer species and also our fox and wolves has been seen to discourage them from drinking from them for periods of time, and therefore they are not cleaned any more frequently than monthly and only using small quantities of Virkon S, which also helps to guard against metals rusting and contaminating water. For deer species, troughs are not cleaned during calving or rutting seasons to avoid disrupting deer and for staff safety, however are cleaned as close to and following these periods as possible. 

In the photograph to the right, I am shown cleaning the Red Fox water trough on 22 April 2016 after releasing the previous water contents, before then refilling it. After a water trough has been cleaned, it is signed off on the record form shown below. Water troughs I have cleaned are initialled 'AD'. The otter, lynx and wildcat water bowls are omitted from this form as they expected to be cleaned daily rather than monthly.