Yellowtail kingfish

Yellowtail kingfish spawn in the warmer months in offshore and shelf waters, and their early life is spent somewhere completely different from their adult habitat.

SPAWNING IS IN SPRING AND SUMMER, in warm shelf and offshore water, triggered by rising temperature. It is batch spawning over an extended period with high fecundity, and eggs and larvae are pelagic.

JUVENILES ASSOCIATE WITH FLOATING OBJECTS. Young kingfish live under drifting weed rafts, debris and floating structure in open water, which shelters them and concentrates the small prey they need. That drifting phase determines the year class and is invisible to any survey of the reefs and pinnacles adults occupy.

THEY RECRUIT TO STRUCTURE AS THEY GROW, moving to reefs, pinnacles, islands and wrecks.

MATURITY COMES AT A FEW YEARS and growth is fast, but the species is long-lived and reaches large sizes, so the biggest fish are considerably older than maturity.

POPULATIONS ARE REGIONALLY STRUCTURED, with movement studies showing both resident fish and individuals travelling very long distances, so a local population is not necessarily a closed one.

AND THE AQUACULTURE CONNECTION IS WORTH NOTING: the species is farmed in several countries, and escapes and interactions between farmed and wild fish are a recognised management consideration in those regions.

Yellowtail kingfish seasonality is a temperature-driven coastal movement, and at the cool end of the range it produces a sharply defined season.

WARMING WATER BRINGS THEM. Kingfish move poleward and inshore as surface temperature rises, arriving on temperate coasts in the warm months and thinning as water cools. At the cool margins this is a genuine presence-and-absence season; in warmer parts of the range fish are available year-round.

SO THE SEASON MOVES WITH THE WATER. Warm-water intrusions — an eddy, a current pushing further along a coast than usual — can bring kingfish early, late or to places they are not normally caught, and the fishery follows sea surface temperature rather than the calendar.

BAIT CONCENTRATIONS SET THE LOCAL PEAKS. Kingfish follow schooling baitfish and squid, and a headland, pinnacle or island fishes when the bait is holding there.

CURRENT IS THE DAILY VARIABLE. Kingfish hold on the up-current side of structure and feed on what the flow delivers, so a mark works on a tide and dies at slack.

SPAWNING IN THE WARM MONTHS overlaps the peak fishing season, which is a biological fact rather than a suggestion.

AND THE SOUTHERN HEMISPHERE TIMING IS THE USUAL TRAP: the warm season straddles the turn of the calendar year, so northern month references are six months wrong.

Yellowtail kingfish handling is dominated by the sheer intensity of the fight and by where the fishing happens.

THE FISH DOES NOT QUIT. Kingfish run hard, repeatedly, and continue to the point of physiological collapse. A fish landed on light tackle after a long fight is severely lactate-loaded and will frequently die after release even if it swims off. The single most effective welfare measure in this fishery is heavier tackle and a shorter fight, which is precisely the opposite of the sporting instinct.

THE FISH IS NOT DANGEROUS to hold — no cutting teeth, a rasping pad in a strong jaw. The caudal scutes are sharp and the gill covers are hard-edged. It is a heavy, muscular animal and it thrashes powerfully, so support it properly and expect to be beaten about the legs.

RELEASE IT IN THE WATER. Unhook boat-side, or in the shallows, and revive by holding the fish upright and moving it forward until it drives away. Expect it to take time.

AND THE ROCK-FISHING CONTEXT IS THE REAL DANGER. A very large proportion of land-based kingfish fishing happens from exposed rock platforms on coasts taking ocean swell, and the combination of a fish that pulls extremely hard, an angler braced at the edge, and a sea that does not warn is the mechanism behind fatalities in this fishery. No fish justifies the position that makes it landable. Being prepared to lose a fish is part of the handling procedure here, and it is the part that matters most.

Yellowtail kingfish are a pelagic predator that behaves like a structure fish, and reconciling those two things is the whole of their habitat description.

THE ASSOCIATION IS WITH HARD STRUCTURE STANDING IN MOVING WATER. Kingfish occupy temperate and subtropical coastal and offshore waters and concentrate on pinnacles, reefs, drop-offs, islands, headlands, wrecks, buoys, pontoons, aquaculture structures and current lines. What each of those has in common is that it disrupts flow and concentrates bait. A featureless piece of open ocean at the same depth and temperature holds nothing; the pinnacle a hundred metres away holds a school.

CURRENT IS THE ACTIVATING VARIABLE. Kingfish sit on the up-current or down-current side of structure depending on conditions and feed on what the flow delivers. A mark that fishes well on a running tide is dead on slack water, and that is a habitat statement rather than a mood: the animal's feeding strategy depends on hydraulics, so the habitat only exists when the water is moving.

TEMPERATURE SETS THE SEASONAL AND LATITUDINAL DISTRIBUTION. Kingfish are a warm-temperate species that moves poleward and inshore as water warms and retreats as it cools, so at the cool edge of the range the fish are a summer proposition and at the warm end they are resident. Currents that carry warm water along a coast extend the habitat as a moving feature rather than a fixed one.

DEPTH USE IS BROAD AND SIZE-SORTED. Small kingfish school heavily in shallow inshore water, around harbours, moorings and shallow reef; large fish are more often deep, solitary or in small groups on offshore pinnacles and wrecks. So the same species provides a light-tackle inshore fishery and a heavy deep-jigging fishery, and the ground is different for each.

AQUACULTURE AND ARTIFICIAL STRUCTURE ARE GENUINE HABITAT for this fish, not an anomaly. Kingfish aggregate around sea cages, moorings and offshore installations for the same reason they aggregate on a pinnacle, and in several regions the artificial structure supports a substantial part of the accessible fishery.

AND JUVENILES USE FLOATING OBJECTS, which is a different habitat again — young kingfish associate with drifting weed and flotsam in open water, a nursery strategy that puts them somewhere entirely unlike the adult ground.

Yellowtail kingfish methods all rest on one condition, and without it none of them work: there has to be current running over the structure.

THE FISH FEEDS ON WHAT THE FLOW DELIVERS PAST A PINNACLE, REEF OR WRECK. The record's habitat section explains this — kingfish hold on hard structure in moving water and take what is disoriented past it. A mark that produces on a running tide is dead on slack water, and anglers who fish the slack conclude the fish have gone.

MECHANICAL AND SLOW-PITCH JIGGING ARE THE DEEP-WATER METHODS. A metal jig worked vertically over structure reaches fish holding deep on pinnacles and wrecks, and it is efficient, physically demanding and extremely effective. Slow-pitch technique — letting the jig flutter on the drop rather than driving it — takes fish that will not chase a fast retrieve, and is the more productive of the two in cooler water.

STICKBAITING AND POPPING WORK WHEN FISH ARE HIGH IN THE WATER, over shallow reef, around islands and on bait schools, and produce the surface takes the species is known for.

LIVE BAIT IS THE MOST RELIABLE METHOD FOR LARGE FISH and is honest to say so. A live squid, yellowtail scad or slimy mackerel fished near structure in current takes bigger kingfish more consistently than any lure, which is why the serious fisheries invest so much effort in catching bait first.

BERLEY AND BAIT PRESENTATION BRING FISH UP in some fisheries, particularly around moorings, cages and shallow reef, converting a deep structure fishery into a surface one.

THE FISH RUNS FOR THE STRUCTURE IMMEDIATELY AND THAT DECIDES THE TACKLE, exactly as it does for pollack and giant trevally: the first seconds are the fight, and heavy drag and lifting power are what land fish rather than what tires them.

AND SIZE AND BAG LIMITS APPLY IN THE RELEVANT JURISDICTIONS and differ; kingfish are also a species where large individuals are frequently released, and a short fight in warm water is what makes that release worth anything.