The river Moy drainage system is not noted for sea trout fishing. A few are taken in Loughs Conn and Cullin every season, and night fishing on the Moy, with the fly, during August does produce some decent fish from the Foxford waters. Salmon anglers occasionally take the odd specimen when fishing fly, but this is rare enough. It may be surprising to some that the estuarine waters of the Moy, from Ballina down to the sandbanks at the mouth of the river, are always full of fine sea trout. Study suggests that these fish are not native to the system, but almost certainly come from waters to the north of County Mayo. In a sense, the Moy estuary can be regarded as a 'Pit Stop' for sea trout feeding down the coastal waters, and the probable attraction is the amount of natural food available. There are vast shoals of sand-eels, large numbers of Herring and Pollack fry and innumerable Shrimps. Indeed, the food density can be so high, that the sea trout are over-fed, which occasionally makes them difficult to catch.

Angling books which deal with the topic of catching estuarine sea trout invariably base their approach on the concept that these are fish native to a specific river and behave in a particular manner. This bears little relationship to the behavioural patterns of these 'visiting' fish. For instance, separate shoals of sea trout which arrive independently of each other, tend to maintain their separate identities without intermingling, and there is a marked tendency for them to adopt clearly defined territories. Fish in the individual shoals are usually of like size, to that it is not unusual to locate a shoal in which the average size is, say, two pounds, and be able to relocate that same shoal in more or less the same area, for up to a week or more. Similarly, one can also locate a shoal of rather small fish in an area, and the wisest thing to do is move elsewhere in search of more sizeable opponents.

Towards the mouth of the estuary, it is likely that the main food item will be the sand-eel, but the closer to Ballina that one fishes, the higher the probability that herring or pollack fry will be the prime food supply. Most anglers carry frozen sand-eels for use as bait, plus a supply of salted mackerel fillets from which narrow strips are cut in imitation of small fish. The tackle is simple; a lightweight spinning rod, small spinning reel loaded with light monofilament line with a swivel attached to the business end and any necessary weight added immediately above the swivel. The hook link may be up to 6 feet in length, armed with a twin hook rig for sand-eel, or a single hook for mackerel strip. Hook sizes are Nos 8, 10, 12 according to bait size. It is essential that the reel line is no more than 4lb or 5lb breaking strain, with the hook link preferably 1lb less than that. Use of thicker line reduces the catch rate unacceptably. Clearly, with this fine tackle, plus the ability of the hard-fighting sea trout to use the current flow to it's advantage, the rod must be very sensitive and not the poker-stiff weapon in common usage.

Much of the fishing is undertaken from largish boats, capable of allowing four or five anglers to fish in comfort and it is perhaps because of this that very little attention has been paid to fly fishing in the salt or brackish water. Indeed, in the breezy conditions that often prevail, it could be extremely dangerous to attempt casting a fly in the company of three or four other anglers. However, it is possible to fish from a smaller, open boat of the nature of the boats used for lough fishing and although more research needs to be completed into suitable patterns of fly, it is already clear that great sport is to be enjoyed.

The lure patterns which are used so successfully for rainbow trout, particularly the fly imitating varieties, seem to offer the best prospects and in addition, there is a range of sandeel imitating varieties salt water flies which, if copied in smaller sizes, should provide positive results. This refers specifically to fishing in the salt or brackish waters of the estuary, but also further upstream, where the water is generally fresh, considerable success has been achieved by anglers wading the river over the period of about two hours before low tide, to two hours after. No clear favourite patterns have emerged, with any of the standard trout wet fly patterns producing fish, but some anglers believe that black and silver patterns, such as Black Pennell, are likely to prove most efficacious. There is always the chance of hooking a salmon too, in the fresh water, so it is advisable to ensure that the fly reel is provided with at least seventy yards of backing line.

It is also possible to fish from the sandy beaches near the estuary mouth, and the angler has a variety of options ranging from free-lined sand-eel or mackerel strip, fly fishing with fry-imitating pattern, or
spinning with small lures. The latter technique is usually the least effective, but just occasionally produces red letter days.

Local advice is always available regarding the estuary sea trout fishing, both in terms of the quality of fishing at any given time, the tackle and baits (or flies) that are most likely to produce results, and the general size of fish that may be expected to be caught. Bookings can normally be arranged, either for individual anglers, or for small parties. However, it should be remembered that the estuary is fairly exposed and in strong winds it is unlikely that boats will venture forth. This should be no deterrent to the bank angler.

One thing must be borne in mind. In order to fish for sea trout, the angler must be in possession of a current salmon fishing licence, and regular checks are undertaken by Fishery Board Bailiffs to ensure
that current licences have been purchased.