Cormorants: convenient scapegoats for Ireland’s salmon crisis
The Great Cormorant (Phalacrocorax carbo) is a much misunderstood bird which has been persecuted for centuries - just because it eats fish. These stunning and vulnerable birds are currently subject to hate campaigns by fishing groups calling for culls. However, there is no scientific evidence that culls would solve conflicts or replenish fish stocks. We need to stop blaming natural predators and address the real problems facing our aquatic ecosystems.
Cormorants are native to Ireland, and their presence on rivers and lakes is entirely normal. It is a myth that they are a non-native invasive species that should not be here. The Irish names for cormorant are Broigheall or Cailleach dhubh. These birds have shared our rivers and lakes with salmon long before humans began managing them as fisheries. Both subspecies that occur in Ireland (P. c. carbo and P. c. sinensis) are native.
These protected birds are part of our coastal and freshwater ecosystems, with as much right to inhabit a river as the salmon swimming beneath them.
The idea that cormorants are seabirds that have invaded freshwater because the sea has run out of fish is also a myth. They naturally use both environments and are more accurately described as waterbirds. Cormorants were intensively persecuted in the past, while pesticide pollution further damaged their populations. Legal protection and reduced pesticide contamination allowed depleted populations to recover from the 1970s onwards. Recovery is a conservation success, not evidence that a native species has become an invader.
Cormorants do indeed eat fish, including young salmon. But seeing a bird swallow a fish does not establish that it is driving a population decline. Predation is a natural and ecologically important process alongside which salmon have evolved.
Native predators like cormorants are not a key factor in the decline of salmon populations. The major pressures on salmon include deteriorating water quality, habitat loss and degradation, dams and other barriers, salmon farming, and changing conditions in the North Atlantic. Overfishing has also contributed historically, and salmon bycatch in other fisheries remains a problem.
However, it is easier to blame cormorants than to address the real issues. They are conspicuous, their feeding is visible, and killing them offers a tangible action. Addressing sewage discharges, reducing agricultural runoff, removing dams, and confronting aquaculture interests are far more challenging. A dead bird can be presented as progress while the conditions responsible for declining fish populations remain unchanged.
Predation can matter locally, particularly where fish are concentrated, for example below a weir or dam. But this is a fish passage issue, and the solution should be restoring fish passage. When we channelise our rivers and remove all the riparian trees, then stock these rivers with hatchery-reared fish, we should expect problems from predators. The solution here is river restoration.
The hostility and prejudice against cormorants have deep roots, and they have been unfairly hated for centuries. Milton used the cormorant to symbolise ultimate deception and malice when Satan disguises himself as a cormorant to sneak into the Garden of Eden. Even today, some anglers still refer to them as the “black death” and the “devil bird” and consider them to be key cause of the decline of fish like salmon in our rivers. But these claims are not supported by science, and cormorants can actually bring ecological benefits including controlling non-native invasive fish species.
The fact that cormorants nearly went extinct in the mid-20th century should remind us how vulnerable they are. Their restricted breeding distribution makes them particularly vulnerable to persecution. Culling cormorants will not clean polluted water, restore damaged habitats, or remove the dams blocking salmon migration. Reducing cormorant numbers is not a practical or sustainable option, and it will not solve local conflicts or replenish fish stocks.
A river is an ecosystem, not simply a supply of fish for people to catch. Native predators are part of its food web, and their right to exist should not depend on whether anglers welcome them.
Protecting salmon means restoring the conditions that allow wild populations to thrive alongside their natural predators. Every debate that ends with blaming cormorants, while leaving those conditions unaddressed, lets the real causes of decline off the hook.