Blue shark are usually caught at or near the surface. Float fishing with the aid of 'rubby dubby' is the traditional method, though a version of fly fishing has been tried with some success. Fishing is generally done on the drift but the system works reasonably well at anchor too if the current is not too strong. Though an oceanic species, blues run quite close to shore around some parts of Ireland and can often be caught within two or three miles of the coast. They will take any kind of fish bait. They are by nature carrion-feeders so there is no need for it to look like a live fish.
Apart from the trace and a float (usually a balloon), blue shark fishing does not call for any special tackle. Ordinary 50 lb or 30 lb class equipment, with enough line on the reel to cope with a shark's initial run, is perfectly adequate. Traces need to be long and wire throughout. Small blues, especially, have a tendency to roll up in the trace, often getting it in their mouth in the process. They have cutter-like teeth that can sever light wire with ease and make short work of heavy nylon monofilament.
However, trace wire should not be excessively heavy. If the line breaks and the fish escapes it has little chance of ridding itself of the trace. Moreover, many hooks sold as 'shark hooks' are far too large. They cause unnecessary damage to the fish and difficulty in unhooking them. Medium-sized hooks with the barb crushed down or filed away are much better and just as effective. Circle hooks are good too, though it is even more important in their case to remove the barb.
Blues are not the most endangered species of shark but they are nonetheless vulnerable, especially to the shark fin trade. Anglers in Ireland have long since appreciated the need to return their catches safely to the sea. By tagging sharks they have also made a significant contribution to scientific research. Sharks tagged in Ireland have been recaptured all over the North Atlantic, nearly to (but never across) the Equator.
However, some angling practices are not conducive to a shark's welfare. For example, the use of ultra-light tackle. For a shark to survive capture and release it must not be played for too long. Otherwise the build-up of lactic acid in its muscles may prove fatal, even days after it is released. Tackle needs to be up to the task. Moreover, light tackle inevitably brings an increased risk of line breakage. That may be acceptable to the angler but it is a more serious matter for the shark which swims away with a long wire trace trailing from its jaws.
Shark fishing has a special fascination for many anglers. Because they are abundant and relatively easy to catch, blue shark are the backbone of the sport in Ireland. Blues (especially males) can be a lively enough proposition on rod and line, but sooner or later an angler fishing for blues in Irish waters will encounter a porbeagle or maybe even a mako shark. When they do they find themselves up against an even more feisty opponent.