By Richard Ziert
Strip Pits, or quarries are fun in their sense of local wilderness, they are often uncrowded, and can give up some giant fish to the daring soul. Yes intrepid to say the least, because many are unregulated and off the beaten path. Common strip pit species include, largemouth bass, smallmouth bass, striped bass, white bass, other sunfish family friends, channel catfish, walleye, sauger and musky.
Strip Pits are the result of abandoned mining operations; where the pit fills in with water from one source or another. These pits can be both deep to 100 or more feet, and of various surface acres. To avoid winter or other die offs, pits should be at least 8-15 feet deep with at least some additional source of dissolved oxygen. At a half acre or so, averaging to about 250 acres, or as large as the monster, and controversial “Pebble Mine Project” brewing in Alaska of 10 square miles, no two are exactly alike.
Pits along mining roads receive the greatest fishing pressure. Others, a little further off the track, are visited by car toppers and belly boats. Nowhere in all of “fishingdom” does knowledge of the environment pay off more than with Strip Pits. Part of that familiarity starts with the digging/removal process, type of mineral extracted, and processing.
Whether it be coal, iron, copper, gold, limestone, or granite rock and gravel, etc. one thing in common is how the materials are extracted. For our purpose the best pits are “Contoured Stripped”, where the top soil, or overburden above the mineral seam, is removed along the natural contours of the land. Followed by auger mining into hillsides, this method leaves behind terraces; irregular stair step ledges similar to some hillside rice patty agricultural layouts you may have seen.
Some minerals leave behind toxic waste not only in their contact with subsequent water fill, but in their necessary processing with various chemicals. pH content, dissolved oxygen content, and terrace layout of and in the water, play key roles in whether or not a particular pit will be “high percentage fish productive”.
A simple and inexpensive pH Meter sold at aquarium/pet stores will tell us all about this end of water quality. Neutral pH is a 7 on the meter. Below 7 the water is acid, above 7, the water is alkaline. With a little leeway the water quality we want is from 6 to 8 on the meter. Too low, or too high a reading produces poor aquatic reproduction, growth and survival. A word of caution is necessary here in that only one pH reading may not represent all the water of larger pits.
Smaller, more protected pits, will have less likelihood of a good wind driven dissolved oxygen mix. Unless it can be determined that the source of incoming water is something more than run off or rain, these smaller pits may not have sufficient oxygen content. These “other” sources can be stream inlets, outlets, underwater springs, or in some cases water input or drawdown from regulated sources or dams.
Fish spawning and equally critical insect reproduction usually occurs in water less than 15 feet. If we were to view our chosen pit as a whole, we would ideally need 10 to 20% of the surface area as spawning grounds of one form or another. Water level and depth/width of the first shoreline terrace is critical. In addition however, artificially planted/sunken habitat - lay downs – brush piles - can act in place of what occurs naturally as well as create sustaining cover throughout the year. Couple this with planting along known paths of wind, surface, or underwater current, next to deeper water will produce the best set up imaginable. Spot planting of cover is ill advised. It is much better to plant several structures within a few yards of each other, and over many yards of bottom contours. Some pits have naturally occurring shoreline trees and brush. Lay downs, aquatic vegetation (if any), overhanging shade producers, along with strategically planted cover, can produce an ideal ecological community unto itself.
The message is then don’t be fooled by water clarity, or any one part of the surroundings alone. If for no other reason, take the necessary readings, make credible observations, do the extra work, to add measurably to your confidence level, and success.
Personal experience of author.
The Mining Industry.
Various state DNR Agencies.
Missouri Department of Conservation/ Managing Strip Pits as Fisheries – 06/2000
The Trout Underground – Pebble Mine Project, Tom Chandler, 9/1/2007
Very Interesting post found at:http://www.bigindianabass.com/big_indiana_bass/