There are two ways to net a koi or goldfish: the wrong way and the right way.
If you put the net in and start chasing your fish you're doing one thing and that’s causing your fish to suffer undue stress, thus the fish is primed to escape the threat and it will actively thrash about trying to find its way back into the pond and have been known to jump clear over your shoulder (it happened to me once).
This is dangerous and is most likely when netting damage can and often does occur, usually because the fish owner has employed the wrong sized net to catch the fish in question.
It can cause severe stress and scales can be damaged (in some cases knocked off the sides of the fish completely).
So let's look into safe netting procedures:
1) Ensure you have the correct sized nets for the job.
2) Koi are wary of the net and learn to avoid it like the plague (leave the net in the pond overnight).
3) Depending if you wish to bowl your fish or bag it you'll need the large 22" pancake net and the bowl for the other option you'll need a sock net.
Please note, if bagging your fish always fast them before transporting. We normally stop feeding 6 days prior to any move.
3a) Bowling a fish is quite a simple procedure, you need the 22" pancake net to simply guide the fish towards the bowl which has been floating on the ponds surface. Dip the edge of the bowl under the net and simply guide the fish in.
3b) First fill the plastic bag to the required depth normally enough to cover the fish but no more.
3c) Using the 22" pancake net guide the fish towards the surface again without the net touching it until the net is just below the surface of the pond.
3d) Using the sock net (pre-wet prior to using), net the fish head first and grasping the other end of the net lift the fish clear of the 22" pancake net and place the end of the net over the plastic bags (always double bag koi) and allow the fish to slide slowly head first into the plastic bag.
4) Disinfect both nets and leave to dry ready for use.
5) If you're taking the fish to a show in which the fish are placed into a vat, catching them becomes harder at the end of the day so it’s always a good idea to take along an extra net.
6) If catching a fish from a vat make sure you and a friend are coordinated so that the stress of the day doesn’t get worse by being chased around a show vat.
7) Slowly but surely guide the fish in question till it is stationed over the 22" pancake net, then with the pancake net guide your fish to just below the surface, then as before scoop your fish into the sock net and directly into the plastic bags used for transporting your fish.
After adding Oxygen from a bottle and sealing the bag, it's an idea to add a black bin liner to help with any further stress of transportation.
We also use a product called Elbagin as a de-stressor at the start of any journey with our fish bagged again. All thoughts given to the fish and its rate of stress and by adding Elbagin we actively strive to lessen it that much further. You can buy it from any good koi outlet and it has many other uses.
If using this product for the first time just sprinkle a pinch of the crystals do not go over the top it has been known to cause mortalities if you do.
We hope this goes a long way in teaching people the correct method of catching fish over that of the wrong method.