Ling

Ling combine three separate problems and boat anglers meet all of them in the same thirty seconds.

THE MOUTH holds bands of small, sharp, backward-set teeth on the jaws and on the roof, which grip rather than cut. A hand withdrawn from a ling's mouth is rasped and held. They are not conger teeth and they are not harmless.

THE BODY IS ELONGATED AND EXTREMELY POWERFUL, and a large ling on a deck behaves much like a conger: it convulses, and it does so after a period of apparent stillness. A fish held across the middle can produce a whole-body movement that nobody expects from something that looked finished.

THE DEPTH IS THE THIRD. Ling are taken from deep rough ground and suffer severe barotrauma. Large fish arriving from depth are often not viable release candidates, and a fish released at the surface floating will not survive. Where fish must be returned, recompression is the only option with evidence behind it.

HANDLING SEQUENCE. Control the head first, using a gloved hand behind the gill covers or a purpose tool, keep the body contained or on a wet surface, and use long pliers. Do not attempt to hold a large ling across the body without head control; that is the arrangement that produces injuries.

AND THE PRACTICAL CONSEQUENCE. Ling from deep water are largely a retention fishery, and the useful decision is made when choosing the mark and the size of hook rather than when the fish is on the deck.

Ling are the clearest case in British sea angling of a species whose fishing is governed by boat handling rather than by biology, and separating those two is the useful thing this section can do.

THE FISH ARE THERE ALL YEAR. Ling are deep-water structure dwellers — wrecks, pinnacles, rough ground, generally in substantial depth — and they occupy that structure permanently. They move to deeper water to spawn in the warmer half of the year in the north-east Atlantic, and outside that they are essentially resident. There is no inshore–offshore migration of the kind that shapes the cod or sole year, and no season in which a wreck stops holding ling.

SO WHY DOES THE FISHERY HAVE A RHYTHM? Because a boat has to hold position over a specific wreck in deep water, and that is only possible when the tidal stream permits it. Too much flow and a bait cannot be got down to the structure, let alone kept on it; the boat is carried off the mark before the gear reaches bottom. The window is therefore around slack water, and it is wider on neap tides than on springs.

THAT IS A CONSTRAINT ON THE VESSEL, NOT ON THE FISH, and the distinction matters because it is almost universally reported the other way round — as though ling feed at slack water. They do not particularly; slack water is when a boat can present a bait to them.

THE FISH ITSELF IS AN AMBUSH PREDATOR THAT DOES NOT LEAVE ITS STRUCTURE. Ling hold in and against the wreckage and take what comes within reach, which is why the fishing is vertical, why baits and lures are worked hard on the bottom, and why a presentation drifting ten metres above the wreck catches nothing at all.

WHICH GIVES THE PRACTICAL SUMMARY: the calendar barely matters, the tide table and the spring–neap cycle matter enormously, and the depth at which the bait is fished matters most of all.

Ling habitat can be stated in one sentence and it is still worth expanding: deep, cold, hard, broken ground, and the deeper and rougher it is the better.

THE ANIMAL IS A CREVICE-DWELLING PREDATOR OF DEEP HARD BOTTOM. Ling occupy rocky reef, pinnacles, boulder ground and — very characteristically — wrecks, generally well down the shelf and onto the shelf edge. They are not a fish of open sand or of shallow inshore ground except as juveniles, and their vertical distribution is deep enough that most inshore angling never meets a large one.

WRECKS ARE THE CLEAREST CASE AND THEY EXPLAIN THE FISH. A wreck provides exactly what ling need: a large complex hard structure standing off a soft seabed, full of holes to lie in, in deep cold water, concentrating prey fish. Ling live *in* the structure rather than around it — inside the hull, under plating, in the internal spaces — and that is why the fishing for them is a vertical, tight-to-the-structure proposition and why tackle loss is part of the fishery. A wreck may hold a population of ling that a nearby open bottom of identical depth holds none of.

TEMPERATURE IS A HARD CONSTRAINT AND IT SETS THE SOUTHERN LIMIT. Ling are a cold-water species of the north-east Atlantic, and the shallower part of their range in southern waters is unsuitable — where the water is warm, the ling are deep. That is why the species is a northern and offshore fish through most of its British range and why it becomes progressively more accessible from the shore the further north the coast.

JUVENILE HABITAT IS SHALLOWER AND DIFFERENT. Young ling use inshore rough ground, kelp and shallow reef, and move progressively deeper as they grow. A small ling from a rock mark and a large one from a wreck sixty metres down are the same species doing different stages of the same life.

THE DIET FOLLOWS THE GROUND. Ling take fish, cephalopods and crustaceans from around and within the structure, and their abundance on a piece of ground tracks the prey the structure concentrates.

AND THE HABITAT EXPLAINS THE STOCK PROBLEM. A long-lived, slow-maturing, structure-bound predator that aggregates on known wrecks and pinnacles is trivially easy to locate and to fish out locally, and ling on individual marks are depleted far faster than the wider stock. Marks do not refill quickly, because the fish do not move much once settled.

Ling reproduction is straightforward in mechanism and consequential in structure, and the consequence is the part worth understanding.

SPAWNING IS A BROADCAST EVENT ON DEEP HARD GROUND. Ling gather on deep offshore banks, ridges and rough ground in spring, releasing very large numbers of buoyant eggs into the water column. The eggs and larvae then drift in the upper layers for an extended period before the young fish settle onto shallower inshore rough ground and work their way deeper as they grow.

FECUNDITY SCALES STEEPLY WITH FEMALE SIZE, AND THAT IS THE KEY FACT. A large old female ling produces disproportionately more eggs than several smaller ones of the same combined weight, and the eggs are frequently of better quality — larger, better provisioned, producing larvae with better survival prospects. So the reproductive output of a ling population is concentrated in its biggest, oldest females.

WHICH IS WHY SIZE-SELECTIVE FISHING HAS AN OUTSIZED EFFECT HERE. Removing the large fish removes the majority of the reproductive capacity while removing a minority of the individuals, and a stock can look reasonably numerous while having lost most of its ability to replace itself. This is the general 'big old fat fecund female' problem, and ling are one of the clearest cases of it in the north-east Atlantic.

MATURITY IS LATE AND GROWTH IS SLOW BY INSHORE STANDARDS, so a ling reaching the size at which it contributes most has taken many years to get there and is not quickly replaced.

AGGREGATION MAKES IT WORSE. Spawning ling concentrate on known ground, which is exactly the ground that is fished, and a fishery operating on a spawning aggregation of large females is operating on the most valuable fish in the stock at the least forgiving moment.

AND THE JUVENILE HABITAT IS SOMEWHERE ELSE ENTIRELY, on shallow inshore rough ground and kelp, which means recruitment depends on inshore habitat that adult-focused management may never consider.

WHAT MAY BE TAKEN, WHERE AND WHEN IS AN ASSESSED AND REGULATED MATTER that differs between areas and is revised. The competent authority is the only source, and nothing above indicates it.