How Tides Affect Fish Feeding Behavior

Most avid saltwater fishermen are aware that all of the world’s oceans experience tides and that both rising and falling tides affect fish feeding behavior. In addition, most saltwater fishermen are aware that the tides are caused by the gravitational pull of the Moon as it rotates around the Earth. Consequently, while some locations around the Earth’s seemingly endless coastline experience only one equal high and equal low tide per day (aka Diurnal), other locations experience two uneven tides per day (aka Mixed Tide) and yet, other locations experience two low tides and two hides per day (aka Semi-Diurnal). However, both Diurnal, Mixed, and Semi-Diurnal Tides each progress approximately one hour per day such that if a high tide occurs at a given time at a given location one day, then will occur approximately one hour later in the same location the following day.

Then, there are also Spring Tides which occur in the period just after a new or full moon and which create the greatest difference between low tide and high tide and, Neap Tides which occur during the period just after the first or third quarters of the moon and which create the least difference between low and high tide. Therefore, because all of the world’s oceans have tides, they also have currents and, these currents act like conveyor belts which create a floating buffet menu composed of various species of baitfish and crustaceans drifting in the water column and thus, predator fish species can position themselves in or, adjacent to, these currents in order to more easily ambush their prey.

However, it should also be noted that while tides are a measure of the change in the vertical height of the water column caused by the gravitational pull of the Moon on the Earth's surface, current is defined as the horizontal flow of water and is caused by rising water levels on an incoming tide and by falling water levels on an outgoing tide. Therefore, while tides are of significant importance to inshore fisherman who commonly fish estuaries, flats, sounds and the surf, they are of less importance to offshore fisherman who fish for pelagic fish species. Of course, the reason for this is that coastal land features guide, restrict and, channel water as the tides rise and fall and thus, they also concentrate schools of baitfish and crustaceans who lack the physical strength to fight the current due to their size which makes them much easier for much larger and more powerful predator fish species to ambush.

However, both baitfish and crustaceans are well aware their vulnerability and thus, they often seek to remain as close to shore as possible because it is more difficult for larger fish species to attack them in shallow water than in deeper water. Thus, both baitfish and crustaceans will often seek shelter in tidal swamps, on tidal flats, in estuaries or, adjacent to the beach during high tides but, they are forced to move back out again as the water levels fall or risk becoming stranded in tidal pools where the dissolved oxygen supplies are very limited. Consequently, because predator fish species are well aware of this daily migration of their food source, they will often take up positions on the edges of cover such as jetties or points or, in transition zones from shallow to deep water or, in depressions positioned between the brake line and the shoreline on exposed beaches where they can ambush their chosen prey as it passes them in the current. Plus, certain species of forage feeders such as Bonefish and Permit often move onto sandy tidal flats to forage as the water level rises and then move back out to deeper water again as the water level falls.

Furthermore, it should be noted that currents are at their lowest at the beginning and the end of a change in tide and accelerate as the water levels rise or fall. Consequently, fishing is often least productive during the slack time between both high and low tides and often becomes more productive as the water levels rise or fall and the speed of the current increases. However, it should also be noted that different saltwater fish species tend to have different preferences for the speed of the current in which they feed. For instance, Cobia, Mackerel, Kingfish, Tripletail, and Sheepshead will often feed most avidly during a slow-moving current but, Spadefish seems to display a distinct preference for feeding during a slack tide. Therefore, the best time to fish inshore waters for ambush predator fish species is after the current flow reaches a speed sufficient to force the baitfish into or out of the shallows while the best time to fish for forage predators fish species such as Bonefish and Permit is generally once the tide has reached its peak.

Also, during the warmer months of the year, most inshore fish predator species inhabit the shorelines of sounds, beaches, and inlets and thus, you should search for such fish near the shallows of small islands as well as channels that drain salt marshes or swamps. In addition, you will also find them near bends in tidal creeks that flow past shell mounds and holding on points with shell covered or sandy bottoms where they can ambush their prey. Therefore, it should be noted that such locations are often produced during the first hour or two of the flood tide and during the last hour or two of the ebb tide. On the other hand, because the ambient water temperature is lower during the cooler months of the year, predator fish can often be found inhabiting the deeper waters of sounds and estuaries in addition to the lower ends of coastal rivers where they will often move into the deeper depressions and holes found in these locations.

So, in addition to climatic conditions such as ambient air temperature, barometric pressure and, wind speed and direction along with environmental conditions such as ambient water temperature, saltwater fishermen also need to be aware of the daily rise and fall of the tides in their locale because tides often create strong currents which can control the movement and distribution of bait fish and thus, the location of predator fish species.

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