Crucians a ideal wildlife pond fish
Now when most ask if they can stock fish into wildlife ponds they often get the answer 'No they will eat everything!' when really its not quite that simple. Fish are part of our heritage and deserve just as most protection as any other species so it just requires a bit of common sense when putting them into a wildlife pond whether its in your garden or a nature reserve.
Which fish can go into ponds?
Its all a matter of pond size, species and habitat. Crucians are nationally scarce and similar to scottish wild cats are being bred out by a similar species in this case the goldfish (ironically crucians are actually gold while goldfish are orange)
They don't grow to huge sizes and mostly eat plant matter and small invertebrates so shouldn't upset my ponds ecosystem.
I wouldn't stock fish into a pond smaller then a bathtub as a rule of thumb as they need space to move around. plenty of weed cover is good so the fish can evade predators themselves and the invertebrate life has a place to hide away. its perfectly healthy to have some predators in a pond to control numbers of species that would normally grow out of control.
Other fish species that can do well in wildlife ponds are 9 spined sticklebacks which our smallest freshwater fish and often end up on the menu for many pond inverts like dragonfly larvae and diving beetles. like the crucian they are nationally scarce. For larger ponds tench, minnows and gudgeon can be great additions.
9 Spined Stickleback
Fish to avoid!
despite there size 3 spined sticklebacks are incredibly aggressive little fish and will bite the fins off other fish in small spaces and quickly eat any small tadpoles or insect life (9 spines are much more placid hence better for wildlife ponds)
Any predatory fish like pike, perch or trout are best avoid for small ponds and even species like rudd, roach and carp will quickly eat small species.
3 Spined Stickleback
Where to get the fish from?
I wouldn't recommend taking fish from the wild as you could be introducing alien species into your pond and damaging wild stocks however there are plenty of fish farms and even garden centres now that sell native British fish for garden ponds.
I'd recommend DC Freshwater Fish Suppliers
Fish Farm Tench
Anything I should do to the pond?
Ponds don't need to be especially deep mine is about 1ft 1/2 at most and good for fish to dig into in the winter months and has lots of weed cover. I don't feed my fish but if wanted to top up there natural diet every now and then any pond fish food will be fine.
I've had common frogs, toads and newts in my pond with the fish and the numbers have stayed the same.
My Wildlife Pond
So why have fish in my pond?
Firstly its a different species to have that would never get into your naturally and if the water is clear enough great to watch swimming around. If your pond is on the larger size and has a good stock of fish you could attract birds like kingfishers which are unlikely to visit if the pond has no fish. Fish are fantastic in there own right and if you can help nationally rare species like 9 spines and crucians by stocking them then its got to be a good thing.
BBC Wildlife Local Patch Reporter
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