Water Clarity and Temperature FYI

[West Basin]

Addition to the FYI - A few fish finding tips when water thermoclines and clarity are in play, now through mid-to-late June:

When the winds blow hard and/or lots of muddy river water flows in, the shallow areas near shore are probably at or near the same temperature and clarity, top to bottom. You will usually see the big muddy areas in these locations on the satellite photos. The colder, denser waters out in the deeper areas don’t mix easily with this warmer water. The warmer water will sometimes ride up over the colder water when currents push them together. They also begin to mix, bringing the water temperature closer together. Similar to slowly pouring warm water into a glass half filled with cold water; the middle of the glass mixes but the bottom stays pretty much cold.

All this current pushing and mixing causes the various areas of water to move and change. Sunlight also warms the water and drives temperature change.

Look for the clarity transitions, especially in areas near shallow to deep water transitions. Currents along these depth transitions can cause several different water clarities and temperatures down the water column. It is these areas that will usually provide the clarity and temperature the walleye prefer at the time. You have to trial and error to find that area and depth. Few fisherman do this anymore, but rig up a thermometer line. Weight at the bottom, then a (waterproof) thermometer tied off from a foot above the bottom every 5 feet up to a foot below the surface. When you pick your first fishing location, drop the line over adjusted for the depth and start fishing. Five minutes later pull up the line and quickly read the thermometer temperatures and write them down. If you see a significant temperature difference between two thermometers (say 55 degrees at 15 feet and 50 degrees at 20), try keeping your lure just above the cooler temperature, or just under the warmer one, and target that layer of water in the water column. You can also use one thermometer, just start at the bottom and read it every 3 minutes, dropping it back down 5 feet shallower each time (one thermometer takes longer but gives you the option to check any depth). If you have multiple temperature differences, try each layer in turn until you find the depth the walleye are at.

If you do this at several locations, you can start to build an area water column temperature map, which can give you an idea of where to move next if no locations so far are producing walleye.

Another thing to keep in mind is a walleye can swim a long way in a short time. A school of walleye can cover well over half the Western Basin (15 miles) in half a day. It doesn’t take that school long to find conditions they prefer at the moment. You may not be marking or catching any at spot A at 8am, but if the conditions change at that location by 3-4pm, it may now be holding walleye. If the fish stay in the water they prefer they will travel within it, moving with the current or circling/swimming around. If you catch them at spot A on Friday memorize the surface clarity and the temperature/depth at which you caught them. On Saturday (same time) look for the same surface clarity, or close, with the same depth temperature you caught them at on Friday. Start there, even if it’s miles away from the Friday spot. It usually takes walleye a few days to transition from one water preference to another when thermoclines are involved, so good water is usually good for multiple days.