Fish farms and stocked ponds lose more stock to birds than most owners realise — a single heron or cormorant can take dozens of fish a day, and a flock can strip a pond in a week. Aquaculture netting is the standard defence, but only if the mesh, GSM and installation match the birds you are stopping.
Different birds need different mesh. Herons are patient waders with a long beak — they need netting held clear of the water so the beak cannot reach through. Cormorants dive, so the net must sit above the surface or line the pond perimeter. Kingfishers and gulls take small fish and fry. Match the mesh and clearance to the species, not to a guess. See our bird netting mesh size guide for the bird-by-bird table.
For most fish ponds, a 25–50 mm mesh is the working range — large enough to let light and air through the water, small enough to stop a heron’s beak and body. For fry and fingerling ponds, drop to 15–25 mm to exclude kingfishers and gulls. The net must be held above the water surface (usually 30–60 cm), never laid on it, or a heron simply spears the fish through the net.
Aquaculture netting lives near water in full sun, so it needs more than the lightest crop grade. 40–80 gsm is standard for overhead pond nets; 80–100 gsm where the net spans a wide pond or takes wind load. Demand UV-stabilized HDPE — the net sits in sun and humidity for years, and a cheap unstabilized net degrades within a season. See how long HDPE netting lasts for the numbers.
| Method | How it works | Best for |
|---|---|---|
| Overhead net | Net suspended 30–60 cm above the water on posts and cables | Herons, cormorants, diving birds |
| Perimeter / side net | Net hung vertically around the pond edge | Wading birds, land predators |
| Fry cover | Fine mesh laid over nursery tanks or shallow areas | Kingfishers, gulls, fry protection |
The overhead net is the most effective for herons and cormorants because it blocks both the standing bird and the diving bird. Run it on posts and a perimeter cable, tensioned so it does not sag into the water, and leave the edges sealed to the ground so birds cannot walk underneath.
25–50 mm for most ponds, 15–25 mm for fry and fingerling ponds. The net must be held 30–60 cm above the water so a heron’s beak cannot reach through.
Barely, at the recommended mesh. The open mesh lets light and air through, which the fish and water plants need. Only very fine fry netting shades the water noticeably.
A UV-stabilized HDPE net lasts 5–8 seasons near water in full sun. The stabilizer is what matters — an unstabilized net degrades within one season.
Hold the net above the water surface (30–60 cm) on posts and a perimeter cable, and seal the edges to the ground. A net laid flat on the water lets a heron spear fish straight through it.
Hold the net above the water and match the mesh to the bird — a flat or loose net is a feeding platform, not a barrier. Tell us your application and we will spec the right net, GSM and size.