deep-water cod, rarely seen at the surface

Size
Length: 40–60 cm, Weight: 0.5–1.5 kg
Lifespan
15–25 years
Diet
Small fish, squid and crustaceans. Hunts in deep water using a streamlined body. Uses its large mouth to capture prey. Feeds near the seafloor at night.
Habitat
Deep continental slopes and seamounts between 300 and 1,000 metres depth. Prefers cold, oxygen-rich waters with rocky or muddy bottoms.
Range
Deep waters around New Zealand from Northland to the Campbell Plateau. Most common on the Chatham Rise and off the west coast of the South Island.
Endemism
Native
Main Threats
Bycatch in deep-sea trawl and longline fisheries. Habitat damage from bottom trawling on seamounts. Slow reproduction makes populations vulnerable to any fishing pressure.
Population
Population trends are poorly understood due to the deep-water habitat. Caught as bycatch in hoki, orange roughy and oreo fisheries. Quota management limits total bycatch.
Conservation Status
Not Threatened
Down in the cold, dark water, where sunlight never reaches and the pressure would crush a human like a grape, Johnson's cod goes about its business with quiet efficiency. It is a slender, silvery fish of the deep continental slope. It belongs to the morid cod family rather than the true cods of the North Atlantic. The distinction matters if you care about fish taxonomy. Most people do not. But they might care that its flesh is firm and white, similar to other deep-water cods. Yet it rarely appears in fish shops. That is because nobody targets it. Johnson's cod arrives on deck only as bycatch. It is an accidental traveller in nets aimed at hoki, orange roughy and oreo. The capture is incidental. The value is low. The presence is unnoticed. You have probably never heard of Johnson's cod. That is fine. It does not seek fame. It spends its days between 300 and 1,000 metres down. It hovers near seamounts and submarine canyons where cold, oxygen-rich water flows over rocky or muddy bottoms. It eats small fish, squid and crustaceans. Hunting involves a large mouth and a slow, steady swimming motion. At night it rises closer to the seafloor to feed. Then it sinks back into the darkness. The cycle is repetitive. The environment is stable. The life is obscure. The depth provides isolation. Several related deep-water cods live in New Zealand waters. Johnson's cod is the one with the widest global range. It turns up in the North Atlantic and the Southern Ocean as well as around New Zealand. But wide range does not mean well understood. Population trends for this species remain unclear. It reproduces slowly, which makes any population vulnerable to sustained pressure. The deep sea is not a place for quick comebacks. The recovery is glacial. The risk is cumulative. The management is reactive. New Zealand's quota management system caps the bycatch that can be taken. But better species-specific data is needed to know whether those caps are set at the right level. Until then, Johnson's cod swims on. It is largely ignored. Largely unknown. Perfectly at home in the dark. The ignorance is systemic. The survival is accidental. The future is uncertain. No one told it otherwise.