Exploit the Spoils

Ecosystems generally exist in a somewhat tenuous state, so even subtle changes to aspects of their designs can carry consequences. Wildlife populations usually suffer when human beings alter natural landscapes. In the marine world, human alteration of ecosystems often involves people digging channels or erecting structures like jetties and dikes.

On the Texas coast, the development of residential neighborhoods along the edges of our bay systems has certainly created problems for marine organisms. For instance, digging canals on the inland sides of barrier islands has changed the designs of some of our bays, eventually by diminishing the amount of seagrass and sandbars which "protect" the interior of coves from the destructive effects of strong north winds. Over time, this can nearly eliminate coves and back-lakes as features, to the detriment of the creatures who thrive in these kinds of places.

Currently, state authorities implement plans intended to reverse the negative effects of developing canal-based sub-divisions on our barrier islands. This type of cycle has repeated itself many times over recent decades, because people regularly make changes to ecosystems without fully understanding the consequences of their actions. However, these truths don't always apply. Sometimes, human alteration of a natural system provides benefits to local wildlife populations.

As a case in point, we might consider the benefits provided by two major man-made features of our inland waterways. In order for modern industries to flourish, boats and barges need to move around in our marine waters as freely and safely as possible. This necessitates the dredging and maintenance of deep ditches in the bays. Various kinds of corporate entities use two main types of ditches to efficiently transport goods by boat from place to place.

Deep channels connecting the Gulf to facilities lying alongshore in the uppermost parts of our bays allow ships to bring gigantic loads of goods into our ports from all over the globe. The intracoastal waterway generally facilitates moving materials on barges from state to state and across the border into Mexico. In addition to serving different industrial purposes, ship channels and the ICW vary in another significant way―ship channels are significantly deeper than the intracoastal waterway.

In order to create and maintain both these types of channels, the Corps of Engineers regularly completes dredging operations. During these events, machinery digs material out of the bottom of the ditch and pipes it away from the depths, where it's dumped back into the water, or onto an existing island. Over time, this process generates what we know as spoil islands, or spoil banks. Some spoils always have parts protruding from the water, while others always have some water covering their entire expanse.

The material comprising spoil banks varies from place to place. On the Upper Coast of Texas, where our bays generally have lower salinity levels than on the Lower Coast, spoils often start off as muddy humps, but they can become covered with live oysters over time. In the Coastal Bend and in both Laguna Madres, spoil banks often start off as sand bars, sometimes a mix of rocks and sand, and they generally become adorned with grass beds as time passes after their creation.

These evolving structural features provide at least two things which can prove beneficial to birds, fish and other creatures. Structural elements with shallow water and cover elements on the bottom in close proximity to water of greater depths offer feeding stations near places where fish can seek safety and comfort during extremely hot or cold weather. The grass beds and reefs associated with spoil banks attract all kinds of marine life, including numerous species of small critters, on which predators like speckled trout, redfish, flounder and other gamefish feed. Spoil banks protruding from the water attract birds, some of which use them as roosting sites, when they're breeding.

Conservation groups currently construct platforms which wading birds can use as nesting sites on some spoil islands. Aided by the absence of predators, other species of birds, including the threatened Black Skimmers, successfully nest right on the ground on these little oases. Some of these breeding birds won't return to their nesting sites if spooked off them by intruders. In deference to the birds who depend on spoils for their survival, people should avoid beaching boats and walking around on the islands to throw cast nets for bait or to access wading spots. Many of the spoils recognized as most important to avian wildlife have signs surrounding them warning anglers to stay away.

Most of the time, walking around on the exposed parts of spoil banks proves counterproductive for anglers anyway. Spoils, like all other structural elements, generate sweet spots, or micro-spots, where fish often show up to feed and where anglers can expect to catch fish at a higher rate than in other places. In order to optimally target fish using these micro-spots, wading anglers usually benefit from staying off the shallowest portions of the spoils and casting toward them from the depths. This same truth obviously applies to boating anglers; the best plan for targeting fish on spoils from a boat involves using an anchor or trolling motor to keep the boat well away from the structure and casting toward it.

Different types of spoils dictate different types of strategies, for those attempting to maximize their catch-rates. On the Upper Coast, spoils crusted with oysters often have subtle trenches in them, which funnel tidal currents and create enticing ripples in which predators actively feed. Anglers throwing lures upcurrent toward the cracks in the reefs and retrieving them down-current or at least cross-current normally succeed in getting more bites than folks who fish with less precise methods. Predatory fish often prowl around directly over the shell on spoils like these when tides reach high levels, while they retreat to the muddy edges of crunchy spoils when the tide drops out.

This same kind of scenario plays out on spoils in deep South Texas, ones comprised of a mix of sand, rocks and grass. On these kinds of spoils, especially in summer, trout and reds often pressure mullet into rafts over the shallowest crowns of the structures late at night, feasting on them actively soon after the sun rises. Later in the day, with the sun straight overhead, those same fish will move toward the edges of the spoils, where they loaf and feed less actively. Spoils in areas with minimal tidal movements, such as in the Upper Laguna Madre, still have micro-spots on them, usually related to the details of their design features and the way grass beds grow to adorn them. Many of these micro-spots lie on the side of the spoil most often exposed to the effects of the prevailing winds during the warm period, meaning on their eastern and southern sides.

This generalization relates to a broader one related to wind direction and structural elements. Most of the time, the windward side of a structure has better potential than the leeward side. Winds above about twenty knots can render this truth obsolete, but it holds true more often than not. On spoils with wide, grassy crowns, working the upwind side by walking in deeper water and making long casts toward the shallows often produces the best results. This pattern regularly plays out in spring and fall, with water temperatures at moderate levels and lots of trout and redfish feeding in depths of two feet or less.

Of course, anglers have no way to fish some of the spoil banks in the Lone Star State by wading. The spoil banks lying adjacent to the Galveston Ship Channel, for instance, vary in depths on their shallowest parts from about four feet to about nine or ten feet. In these places, anglers fishing out of boats do well targeting trout either with live croakers, or less often, by throwing soft plastics on heavy jigheads and working the lower parts of the water column. On some occasions, the trout in these locations pressure mullet to the surface in herds and become available to anglers tossing topwaters.

As a general rule, spoil banks lying close to ship channels produce better results in the summer, while those lying next to the ICW produce best in spring and fall. Spoils made of sand, rocks and grass tend to produce better in warmer weather, while those comprised of mud and shell produce better in cooler conditions. Across the board, the biggest trout caught around spoil banks often come from portions of them covered by the shallowest water, regardless of the type of material comprising them or the depths of the water in the ditch close to them, and assuming the prevailing conditions favor the trout using shallow water to feed.

Most accomplished trophy trout anglers target fish in shallower water than others, whether they're fishing spoils or not. Many of the state's top trout hunters do recognize spoil banks as structural elements with tremendous potential to attract and hold big trout, from the LLM all the way to Sabine Lake. Undoubtedly, these man-made features prove advantageous not only to the people of Texas, but also to our fish, birds and other forms of wildlife.