Structure is important when it comes to fishing. In fact, it's everything. Structure is to fishing, what temperature is to baking. It is the measuring stick that fishermen and biologists use to discuss everything from fish behavior to fish survival as it applies to its natural environment. You will also hear some people refer to this as “cover”.
The reason for this is that structure is vital for fish life. Without structure, there are no fish. Structure can be anything including trees in the water, rocks, old cars or boat docks. It's from these locations that fish find protection from predators, strong currents and are able to ambush other creatures in order to feed themselves. It is also the home of the smaller aquatic life that fish depend upon for food. No cover, no food.
Fishermen's interest in structure is almost always as it relates to catching fish. In fact, if you climb in a boat and fish a lake for the very first time, chances are good that you will start your day by throwing lures at whatever cover is visible to you. Boat docks and piles of rocks would be good examples but so are weed beds.
There is good reasoning for this. Fish absolutely require structure and it's usually not a question of whether or not they are stationed around a piece of it but more of a question of how far from its cover is a fish willing to chase a lure? Since fish do not have eyelids it is common knowledge that on a sunny day, they will hug structure very closely and are unwilling to swim very far to catch up to your crankbait. On a cloudy day, however, the opposite is true. On a sunny day with wind-ripples on top of the water, you might discover that fish will chase your bait, just not as far as they would on an overcast day.
Knowing the importance of structure, and the role that it plays, it should not be a surprise that fish management professionals and biologists have been trying to augment a fish's habitat with additional structures wherever they see that the need exists. These manmade or man supplied structures can consist of anything from sunken Christmas Trees to factory manufactured items that are made specifically to increase the survival and propagation of fish species.
There is a lake located near my residence that frequently sinks Christmas trees and tree logs into the lake to act as supplemental fish habitats in areas where those habitats are lacking. This type of habitat, while certainly 'man-imposed' is not 'man-made'. Usually, when we refer to a man-made habitat, we are not only talking about something made from materials that you would not find existing naturally in the fish world, but also natural materials.
A company called Pond King, for example, makes not only a fish habitat that is designed for existing fish but also artificial spawning beds that are designed to provide a place for spawning fish to lay their eggs. Making their devices from polyethylene ensures that the habitat will not degrade or rot, such as a sunken tree might. However, you’ll see later on in this article that, they do not always work as well as the natural materials that fish are most likely to see in their non-fabricated world.
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Should You Create Your Own Fish Structure?
There are many youtube videos available that will show you how to create your own, homemade habitat, but this is something that you will want to use care with. There is a fine line between dumping garbage in a body of water and creating a beneficial structure.
Any item that contains toxic ingredients, such as car tires, should never be used. Besides, unless you happen to own the pond or lake that you are installing the habitat in, you should probably refrain from doing so. The state Department of Natural Resources may take offense to your interference as they manage and monitor most public bodies of water.
Also keep in mind that, in public water, professional fish biologists know precisely where the added habitat is needed in each body only after careful study. As a rule, they do not just randomly sink Christmas trees in an impoundment and hope for the best outcome. There are specific bodies of water and specific locations inside those bodies that are more susceptible to the natural cover being stripped away by strong currents.
Most fishermen love the idea of inserting manmade habitats in water because they believe that this creates a "hot spot" of fishing that only they know about. I suppose if it is a large enough structure another fisherman might spot it on his boat sonar but it's questionable whether or not this is an effective means of predicting where the fish will be. It would certainly be difficult to predict which species of fish may be using the habitat for cover. While studies have shown that a pre-planned habitat does, in fact, attract fish, it may not hold as many as you think if there are plenty of other natural forms of cover to choose from.
With the invasion of the different species of carp, it may be more vital than ever that we provide our native fish species with a place of safety in order to ensure their existence. Carp are especially invasive, not only in their quick breeding habits but also in their diet. They can raid a lot of native species' nests and eat eggs before they even hatch. Nearly the only freshwater fish that can penetrate their scaly armor in order to fend them off (or outright eat them) are Muskies. It is for this reason that many lakes are in danger of containing nothing except those two species.
Success in Saltwater
There has been a tremendous amount of success in creating man-made habitats or artificial reefs in saltwater. Not only has such proactive approaches assisted in reducing beach erosion and helped to add to the protection of natural reefs but it has also given additional cover and structure for the propagation of aquatic animals.
Likewise, there have been many achievements made in freshwater though freshwater requires more consideration than simply sinking something to the bottom. Rocks work well, provided that they are placed in the appropriate spot, in the correct configuration and the comprised of the correct amount. Logs also work well assuming that they too are given the proper consideration before being placed.
The few studies that have been conducted on the benefits of freshwater, man-made habitats, show that vertical cover works best.
Fish Habitat Natural Materials vs Manmade Materials
When it comes to comparing natural materials with manmade materials, one study suggests that fish prefer the natural habitats. In the examination of data collected, fish were more plentiful around placed brush piles (78%) as opposed to polypropylene (17%). While this is just one study and it's unlikely that there have been very many done in this field, it is something to consider if planning the placement of such a habitat in your own pond. It might also be worth keeping in mind before spending a large part of your fishing day looking for these “hot spots”.
While fish seem to prefer natural cover, such as submerged evergreen trees, at least one study has shown that as the natural habitat begins to degrade, so does the number of fish that are attracted to it. This would suggest that this type of man-placed structure needs to be renewed often if the goal is creating a long-term haven for fish. The key to attracting fish to either type of habitat seems to be ensuring that the habitat being used is a vertical structure as opposed to a horizontal one. Fish prefer using structures that allow them to change depth levels and still maintain cover.
I have personally fished in lakes that will either mark their sunken structures on a map or on a web page in the hopes of aiding fishermen to locate them but unless it is a fabricated, man-made habitat, this is not exactly evergreen information. If they fail to keep their information up to date or at least sink newer structures in the same place, it is likely that the information will be useless once the structure decomposes.
As a fisherman, it's great to know that we have come a long way not only in better water qualities but also in learning and understanding what our wildlife needs to survive and renew itself for generations to come. Hopefully, all states are taking such measures to protect our great outdoor resources and ensure that not only ourselves but our children and grandchildren will be able to continue our passions for many years to come.
The greatest inheritance we can leave future generations is the great outdoors.