An estuary is any semi-enclosed body of water which opens into the sea and is also connected to a river. This means that a wide range of fishing marks can be classed as estuaries including the vast Thames and the Severn estuaries, and the Tyne estuary which is formed by two massive man-made stone piers. While these are technically estuaries, the large scale and variety of marks contained within mean that standard sea fishing equipment and methods are needed to fish them. When anglers talk of estuaries in a sea fishing context they usually refer to fishing in the mouth of a large tidal river, such as the River Nith Estuary, pictured below.

The rest of this article will concentrate on fishing in this type of estuary, and does not cover fishing from larger types of estuaries.

Features of an Estuary

As the semi-enclosed environment of the estuary protects it from the weather conditions of the open sea, estuaries offer calm and sheltered fishing. Most estuaries contain sandbanks and sandbars which are revealed as the tide goes out, and boat moorings, harbours and other man-made structures can often be present in this part of larger estuaries, as well as smaller creeks which branch away from the estuary. Estuaries also contain brackish water (water with a salinity of 0.5 – 3 per cent salinity compared to sea water which has a salinity level of 3 – 5 per cent) with the salinity of the water obviously dropping as the distance from the mouth of the river increases. The mix of saltwater and freshwater conditions can produce an interesting combination of species and some productive fishing. Moving further up the river may be grassy riverbanks which look more like a freshwater fishing environment, although certain saltwater species can be caught surprisingly far inland in many parts of the country, meaning that the dividing line between sea fishing stopping and freshwater fishing beginning is often blurred.

Fish Species

As stated the outer area of large estuaries can be very similar to a normal sea fishing environment, meaning that the usual sea fish species can be caught here, such as cod, whiting, rays and so on. However, moving further upriver into the inner estuary will see the salinity of the water drop, meaning that many of the more common sea fish species will be much less numerous here. There are four species which are commonly found in estuaries as they can live in water with low salinity levels and appear able to thrive in an estuary environment. These species are: smaller bass, flounder, silver eels and mullet.

Bass – Bass can often be found in estuaries, with smaller school bass preferring the sheltered conditions which estuaries offers. Many immature bass will stay in and around estuaries for the early part of their lives, only moving away into deeper water when they are nearing fully grown size. Larger bass can also enter estuaries if a food source is present, such as peeling crabs in the spring or large numbers of small prey fish in the summer.

Flounder – The humble flounder is able to adapt to extremely low levels of salinity and can be found so far up rivers in some parts of the country that they are living in an almost entirely freshwater environment fifty or sixty miles inland. This, combined with the fact that flounder are often found feeding in very shallow water (sometimes just inches deep) mean that flounder is a very common species in estuaries.

Silver eels – The silver eel has an extremely complicated life cycle (see more on the full article on silver eels here) and spends its early life in the sea, before migrating up rivers and then, in the later part of its life heading back down rivers and to the sea to migrate. Because of this catadromous life-cycle silver eels are often present in estuaries and are a target of many estuary anglers.

Mullet – The three species of true mullet found in UK waters can often be found in estuaries as they prefer sheltered and calm waters. Mullet will often be found in the creeks and inlets which branch off from an estuary, and if an estuary has a sheltered harbour or marina mullet may also be present in these areas. While mullet are difficult to locate, and even harder to catch, estuaries are often favoured by anglers looking to target this species.

Rods and Reels

The sheltered nature of estuaries means that the tackle used by anglers can be scaled down, as it is rarely necessary to cast long distances or and the lack of strong tides means that heavy weights are unlikely to be needed. For the vast majority of estuary fishing, a bass rod of 11 or 11½ft which is rated to cast 2 – 4oz is ideal, with most anglers pairing this rod with a size 5000 or 6000 size fixed spool reel, although small multipliers are also used. These type of rods are more than strong enough to handle the conditions within estuaries and also offer better bite detection due to their balance and lightness. Additionally, bass rods are not as heavy as full-sized beachcasters, meaning that they are easier to transport from place to place if anglers are on the move around an estuary during a fishing session. A number of manufacturers also offer specialist flatfish rods which are also light and sensitive, making them ideal for estuary fishing.

Tactics

Due to the different nature of estuaries, it is impossible to come up with definitive information about the best way to fish an estuary, although there are some general points which can be made. As with all sea fishing it is a mixture of obtaining local knowledge and trial and error which leads to anglers working out how to get the best results when fishing an estuary.

The diagram below gives general advice on fishing the type of estuary which is typically found around the British Isles.

1. Anglers fishing on the outer estuary into the open sea will encounter conditions similar to normal sea fishing and may need to use standard sea fishing tackle, such as 12ft beachcasters which are capable of casting 6oz weights. Usual sea fish species will be caught here.
2. Sandbanks and sandbars are typical features of estuaries and will become visible as the tide goes out.
3. Fishing inside of the estuary at low tide will allow anglers to benefit from the calmer conditions and move along the exposed sand to fish into the river. Certain species such as flatfish (especially flounder), mullet, bass and silver eels will be more likely to be caught here, whereas sea fish which are usually found in deeper water (such as cod, pollock and whiting) may be less common.
4. Gullies and other food-holding underwater features become revealed at low tide, allowing anglers to note their location.
5. Fishing from the land at high tide will allow anglers to target the gullies which were located when the tide was out. This can prove some of the most productive estuary fishing.
6. Moving inland along the river will see brackish water encountered. Only certain species which can tolerate low salinity conditions such as flounder, silver eels and mullet will be found here. Conditions will also be extremely calm allowing light gear to be used.

Many estuaries will have sandbanks and sandbars which are exposed at high tide as well as gullies and channels running between the sandbanks. Anglers visit an estuary when the tide is out on the lowest of spring tides and make a note of the features which are present. As the tidal flow will push food sources such as marine worms, dislodged shellfish and dead and injured fish into gullies casting into a gully can prove very productive. In some estuaries, it may be possible to walk or wade out onto sandbanks exposed by the low tide and cast a bait into a gully, while other gullies and fish-holding areas may be cast into from the banks of the estuary. As estuaries are often sandy/muddy and snag-free it can be effective to use plain weights and allow the weight to roll and move around, and eventually find its way into a channel or gully.

Lure fishing can often prove effective in estuaries which offer access to deeper water. While the outer area of large estuaries can produce mackerel and other sea species lure fishing in an inner estuary can often prove an effective way of catching bass, although they may often be smaller school bass. High tide, when there is deeper water is usually the best time to lure fish in an estuary, with the flooding tide often bringing small sprats and sandeels into the estuary, and the predatory bass following. Spinners can be effective, as can jelly eels and other forms of artificial soft lures.

When bait fishing for species such as flounder many anglers have success by adding a spoon or other form of attractor blade to the hooklength. This additional form of attraction can often catch the attention of a flatfish, while turning the reel handle several times every couple of minutes, or even constantly reeling in very slowly can cause the attractor blade to spin and kick up sand and dirt from the seabed which is also known to attract inquisitive flatfish species.

Spring can be a productive time in estuaries, as the crabs begin to peel fish will come into the estuary to hunt for this source of food. Similarly, it can be a good idea to use ragworm or lugworm as bait if these worms are naturally present in the beaches near an estuary, especially after a period of stormy weather when many of these worms will have been dislodged from their homes and become an easy food source for the fish which are present.

Rigs and Bait

The choice of rig depends on the species which is being targeted. As estuary fish are generally smaller than fish that may be caught from other areas it makes sense to keep hook sizes relatively small. Due to the sheltered conditions and likely snag-free nature of estuaries it is not usually necessary to use weak links or other anti-snag terminal tackle such as Gemini Breakers or Breakaway Escape Links.

Three hook flapping rigs with small hooks (generally size 2 – 4, and potentially as small as size 6) can be very effective when targeting flatfish such as flounder in estuaries, and the small size of hooks means that other species such as Dover sole and dabs can also be caught if they are present. Estuaries can prove one of the best places to add beads and other attractors to the hooklengths, and some anglers also use attractors such as flounder spoons to their rigs when fishing in estuaries. The three hooks of this rig mean that a good scent trail can be built up, and of course anglers can experiment with three different baits. Lugworm and ragworm are good baits when targeting flatfish in estuaries,  although mackerel or bluey strip and peeler crabs can also be effective when estuary fishing for flatfish.

If bass are the species which is being sought then a simple single hook rig can be a good choice, with a size 1/0 or 2/0 hook in a strong pattern. Many anglers choose to clip down their bait behind an impact shield as this will improve the presentation of the bait and being clipped down prevents larger baits from flailing around and tangling during the cast. The top bait when estuary fishing for bass is peeler crab, although sandeel, strips of bluey and a single large ragworm can all get results.

A good balance between these two rigs can be a two hook flapping rig (pictured left) fitted with size 1 or 1/0 hooks. This type of rig covers all bases as a different bait can be used on each hook and the hooks are small enough for most flatfish species (with the possible exception of Dover sole) to get into their mouths, but strong enough the handle any larger species such as bass, big silver eels or any unexpected species such as cod or rays which may come along.

When fishing for the three species of true mullet in estuaries specialised tackle and tactics are needed, due to the incredibly shy nature of this species and their specific feeding habits. Full details on the methods and techniques needed to catch mullet can be found by clicking here.

Hazards

Despite the sheltered environment and generally calm conditions, it would be wrong to think that estuaries are completely free of danger. Anglers walking or wading out onto sandbanks that have been revealed by the tide should be aware of the tide coming back in behind them and ensure that they are not cut off – this can be a particular problem in large estuaries. Furthermore, the riverbanks in some areas be unstable and potentially and give way underfoot, so anglers should always make sure that they are not too close to the edge and are fishing from a secure and stable platform. Finally, some estuaries are made up of mudflats which anglers can easy get stuck in if they try to cross – a serious problem if the tide is racing in to cover that area. As with all aspects of sea fishing anglers research a new fishing mark in advance, use common sense and avoid areas that may contain any of the dangers described above.