Seahorses are heavily overfished, as are so many other species globally.
Fishing is not necessarily problematic – there certainly are sustainable fisheries globally – but the current cumulative effects of fisheries on seahorses are certainly catastrophic, with wholesale depletion of wild populations. Part of the problem is the way that seahorses are caught. Most are extracted by bottom trawls and other non-selective gear. Such methods of fishing actively pursue fish and invertebrates with little room for escape. They are also captured by small-scale fishers, people who actively seek seahorses, generally using a variety of very simple gears. In both cases, the effects on wild populations are problematic.
Our biggest worry, by far, is the effects of bottom trawling on seahorses and other marine life. Trawling involves dragging a large and heavily weighted net along the ocean floor, catching all marine life in its path while wrecking habitats.
Hundreds of thousands of bottom trawls operate around the world, catching perhaps one-quarter of the biomass reported to the UN Food and Agriculture Organization. Seahorses, which grasp benthic holdfasts and swim very slowly, are extracted by the millions each year. Indeed, seahorses provide an index of trawl pressure. Even in countries where a vessel only catches one or two seahorses per night, the total catch of seahorses for that country can exceed five million in a year. Read more about bottom trawling.
Targeted fishing for seahorses is primarily practised by small-scale fishers, either impoverished people in developing countries or aquarium collectors in developed countries. Most of the fishers in developing countries are trying to catch anything they can, with seahorses as just one possible target. They commonly collect the seahorses by hand or use small dip nets and other low technology. Fishers either sell the live seahorses into the aquarium trade or, if that market just isn’t available, dry the seahorses for traditional medicine or curios. Read more about targeted seahorse fishing.