Weekly Fishing Tip: Understanding the thermocline
Most lakes, sometime during the summer, will develop a thermocline. Understanding how the thermocline works and what it means for your fishing tactics, is important to having a successful day on the water.
Here are a few simple things to keep in mind in relation to the thermocline and its parallel layers.
Epilimnion Layer
This layer is at the top and thus receives the most sunlight. You’ll typically find bluegill and bass (and other warmwater and bait species) here as it’s the warmest.
Thermocline Layer
This is the middle layer. You’ll often find crappie and walleye congregate here.
Hypolimnion Layer
This is the bottom layer and also the coldest and densest. Species you’ll find here include lake trout, whitefish and northern pike.
Keep in mind the thermocline can change day to day and in the fall it will mix with the other layers to create an entirely different dynamic of the lake.
This tip was adapted from Michigan Outdoor News.
Great Lakes Temperature Map
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Southeast Lower Peninsula
Southwest Lower Peninsula
Northeast Lower Peninsula
Northwest Lower Peninsula
Upper Peninsula
Windy conditions are not making it easy for those fishing on the Great Lakes and the large inland lakes. Fish were scattered throughout the water column. Those fishing the smaller inland lakes and rivers are catching bass, bluegills, pike, walleye and a good number of catfish.
SOUTHEAST LOWER PENINSULA
Lake Erie: Had a significant decline in walleye numbers over the last week. A few anglers managed to find fish in Brest Bay, off Stony Point, the Fermi Stacks, and near the Dumping Grounds when trolling crawler harnesses, crank baits or body baits. Yellow perch numbers were good for those still-fishing in 20 to 25 feet in Brest Bay, off Stony Point and around Turtle Island. They are using spreaders with minnows. Emerald shiners worked best. Anglers should note that Bolles Harbor is closed until sometime around Labor Day because of road construction at the entrance into the harbor.
Lenawee County: Devils Lake is producing bluegills in 25 to 30 feet. Use crickets or wax worms near the bottom. Some are getting limit catches. Those trolling for pike have done well in the deep weed lines and points. On Lake Hudson, overall catch rates were down except for bass caught on top-water lures in the early morning or evening.
Detroit River: Most of the fishing activity was taking place early to mid-day but not much has changed. The better walleye fishing on the Canadian side continues to be near the casino, whiskey plant, salt mines and the Canadian side of Belle Isle. Fishing was poor around Mud Island and near the Wyandotte Golf Course but a little better on the east side of Grosse Ile and down near Lake Erie. Most anglers reported zero to two fish. Try 15 to 35 feet when bottom bouncing with crawler harnesses or hand-lining with spoons and stick baits. Boat anglers are targeting walleye, bass, muskie and channel cats but have also caught a few pike, rock bass, white bass and freshwater drum. Catch rates for muskie were slow. Anglers did manage to catch a few large and smallmouth bass. Water temperatures were near 70 degrees.
Lake St. Clair: Bass reports are good with larger fish coming from deeper waters. No reports on walleye or muskie. The mayfly hatch has really dropped off so perch fishing should improve. Try the bulrush beds in Goose Bay and Muscamoot Bay.
St. Clair River: Bass anglers should try all three channels as the fish are looking for cooler water. Target the deeper waters with spinners, plastics or crank baits.
Lexington & Port Sanilac: Those trolling for salmon and lake trout were heading way out to waters 110 to 160 feet deep off Lexington. That is about 25 miles out. Anglers were catching steelhead, lake trout and the occasional Chinook or coho on spoons about 50 feet down. Hot colors were green, blue and silver. Perch fishing was slow at both ports.
Harbor Beach: Those trolling for walleye were heading north towards Port Hope and doing well in 20 to 40 feet. Try hot-n-tots and worm burners with crawlers and spoons. The wind and the cooler water temperatures had the fish scattered. A couple steelhead were taken in the top 20 to 80 feet out near the scum line with clean spoons off downriggers and 5, 7, and 10 color lines with offshore boards. Try straight out and north for lake trout in 85 to 140 feet with spoons and dodgers with spin-glo’s or spin doctors with flies off the bottom. Hot colors were blue, green with a red head or anything that glows.
Port Austin: To Grindstone City was the walleye hot spot with lots of fish including limit catches taken in 20 to 40 feet. Both crawler harnesses and spoons were taking fish. South of Grindstone, the area off the mouth of the New River was also very good. Pier anglers caught a couple smallmouth and the odd walleye at night.
Saginaw Bay: As a general rule, for walleye, lake trout, or whatever, the fish are out deep. They’re still getting some walleye over the weed beds along the inner bay in the early morning, but otherwise go deep. Walleye were caught by those trolling crawler harnesses over the weed beds off the Bay City State Park, the Kawkawlin River and over the Callahan Reef in the early morning. As the sun rises, the fish move out to about 25 feet on the east side of the Shipping Channel. This would put them between the Red Spark Plug (Buoys 11&12) and the Green Spark Plug (Buoys 1&2). Fishing in the Slot was slow with only a few fish picked up along the east side. At Caseville, walleye were caught northeast of the Charity Islands, off Oak Point, Oak Beach and off the Hat Reef. Some perch were caught straight out from Quanicassee in 10 feet.
Saginaw River: Shore anglers fishing the lower river were catching a few smallmouth bass, rock bass, channel cats and freshwater drum.
Sanford Lake: Was still producing good numbers of bluegill and crappie for those fishing the deep edge of the weed beds with small pink or white jigs with twister tails or perch rigs with wax worms over the side of the boat. Good areas were off the Sanford Marina or south of the campground along the flats.
SOUTHWEST LOWER PENINSULA
St. Joseph: Salmon fishing was good but then slowed. The most productive water was about 100 feet deep. Pier fishing is slow for all species. Perch fishing was good with a decent number of fish caught north and south of the piers in 30 feet.
St. Joseph River: Had few trout but good numbers of catfish have been caught.
South Haven: Salmon fishing was good in 110 feet. Anglers are using meat rigs and flasher/fly combos. Pier fishing was slow for all species. Good perch fishing was reported south of the piers in 35 feet.
Kalamazoo River: Those fishing below the Allegan Dam caught the occasional steelhead. A few walleye were also caught. Those targeting catfish have done very well with crawlers, shrimp, chicken liver or bluegills.
Grand Haven: Has not changed. Boat anglers have caught salmon and trout 40 to 100 feet down in 70 to 140 feet with meat rigs and flies. Pier anglers are catching freshwater drum when casting spoons.
Grand River at Grand Rapids: Just one summer steelhead was caught recently but the catfish action continues to be good. Channel and flathead have been caught on crawlers, live or cut bluegills fished off the wall or below the dam. Smallmouth bass were hitting on jigs and live bait in the same area. Some keeper size walleye were caught below the dam. Try artificial baits or live minnows. Bluegills were hitting on crawlers fished off the wall.
Grand River at Lansing: Water levels were higher after the recent storms. Smallmouth bass fishing will improve when the water levels come back down. Those fishing below the dams are catching catfish.
Lake Lansing: Is producing some panfish along with the occasional pike.
Morrison Lake: Was producing a few walleye early morning or late evening. For bluegills, try leaf worms or crickets.
Muskegon: Anglers are finding salmon and trout 45 to 90 feet down in 80 to 150 feet with green meat rigs and flies. Glow spoons are working well in low light conditions.
Whitehall: Fishing slowed but anglers were still bringing in a mix of steelhead, lake trout and salmon including some coho that have started to show up. While it was a little harder to find fish, once anglers did the fish were hitting on almost everything including flies, spoons, meat rigs and copper fished about 55 to 60 feet down in 100 to 150 feet. Blue and green were the hot colors. There was no pier fishing.
NORTHEAST LOWER PENINSULA
Rogers City: Water temperatures have been changing constantly. The good news is a few salmon have been trickling in but the fish are scattered. The better fishing was 35 to 60 feet down in 40 to 90 feet depending on the thermocline. Spoons worked best and the hot colors were blue and silver, green, blue, black and white or anything that glows early and late. Steelhead were taken on orange spoons in the top 30 feet of waters 145 to 225 feet deep. The tribal nets around Forty Mile Point were removed.
East and West Twin Lakes: Fishing has been slow on East Twin for all species. A few perch over eight inches were caught on natural bait. A few bass were caught in four to six feet. The walleye fishing on West Twin was moderate for those trolling natural baits in 10 to 14 feet. Rock bass and perch were found along the weed beds in four to six feet. Smallmouth were caught around Eagle Point and the weed beds near the canal.
Alpena: Offshore winds have prevented boat anglers from heading out too far. When they can, they found a mix of lake trout, steelhead and even a few salmon at the “Humps”, around Thunder Bay Island and out towards the Nordmere Wreck. Spoons seem to work best. Look for walleye in the usual places this time of year like North Shore, Thunder Bay Island, Rockport or south towards Sulphur Island.
Thunder Bay River: Water temperatures are still very warm and not much has been caught. Anglers may find smallmouth bass, rock bass or freshwater drum.
Harrisville: Walleye fishing has been good to the north from Sturgeon Point to the Black River in 12 to 25 feet of water. Anglers are using crawler harnesses or small spoons and body baits in the late evening or early morning before the sun rises. Lake trout were spread throughout in 120 to 160 feet so run your lines from top to bottom. Spoons, spin-glo’s, wobble glo’s and cut bait were producing fish.
Oscoda: Lake trout are scattered throughout in 70 to 170 feet. Anglers reported a good number of walleye south towards Au Sable Point. Late evening was the best time to fish with crawler harnesses, body baits or small spoons. Pier fishing slowed with only a few channel cats and the odd smallmouth caught.
Au Sable River: Had good smallmouth action further upstream. Not only were the fish bigger but a good number were caught.
Higgins Lake: Perch are being caught near the Sunken Island and along the drop-off in 40 feet. Those trolling caught lake trout on gold spoons or body baits. Some brown trout and rainbow trout were also caught up high in the water column. Rock bass can be found throughout the lake.
Tawas: Fishing of all sorts was pretty slow in the bay but the one bright spot was several boats picked up walleye out in 60 feet. Those trolling were marking lots of fish but the bite was not there. Pier fishing was slow with only a couple smallmouth, rock bass or small pike taken.
Au Gres: Catch rates were spotty. A lot of boats were crossing over to fish north of the Charity Islands and around the Steeples but some are also fishing between Point Au Gres and Point Lookout. Either way, success rates were mixed.
Au Gres River: Shore anglers were catching a few pike, freshwater drum and a lot really big channel cats.
NORTHWEST LOWER PENINSULA
Harbor Springs: Most boats are still fishing at Harbor Point or up at 5-Mile Point. They are looking for salmon but catching mainly lake trout which were as shallow as 30 feet down or as deep as 90 feet down in 150 feet.
Petoskey: Had a thermocline about 50 feet down. Anglers are searching for salmon but only catching lake trout. Boats heading towards Bay Harbor and East Park caught lake trout on spoons and J-plugs 70 to 85 feet down. The “Bobber Hole” is still pretty slow. A few smallmouth, rock bass, and bullhead were caught on worms and soft plastics off the D Pier. Smallmouth were caught off the breakwall when using worms, jigs and soft plastics.
Bear River: Water levels were still pretty low. A few small steelhead and rock bass were caught on flies and worms. Smallmouth bass fishing was decent below the power dam for those using minnows or leeches but many were sub-legal.
Charlevoix: Most boats are coming in with lake trout and very few salmon. The lake trout were about 50 feet down in waters over 100 feet deep. Many are fishing North Point, around the can at the Cement Plant or towards Fisherman’s Island with spoons, flies and spin-glo’s. Some reported a few salmon caught north and south of the channel. Boats fishing the channel caught lots of sub-legal smallmouth bass but a few more nice ones were starting to show up. Freshwater drum were also caught. A couple rock bass and smaller perch were taken near the lighthouse when using crawlers, leeches or soft plastics on the bottom.
Traverse City: Lake trout were scattered in the East Bay. Fish were marked anywhere from 60 to 110 feet. Salmon were reported 50 to 80 feet down in 90 to 200 feet but very few were caught. In the West Bay, lake trout were near the bottom in 80 to 100 feet. Salmon fishing was slow but a few were reported along the White Walls.
Boardman River: Brown trout fishing up near Sabin Dam was hit-or-miss for those using flies. Further upstream, those using worms and flies caught brook and brown trout between the “Forks” and Brown Bridge. Some are looking for summer steelhead but few have been caught.
Frankfort: Anglers were heading north and trolling anywhere from 80 to 140 feet down in 150 to 250 feet. They were using spoons and meat rigs in the top 80 feet. The numbers are low but the Chinook are there and the average size was 15 to 17 pounds. Good numbers of lake trout are hitting just off the bottom near Betsie Point.
Onekama: Those trolling the west side of the “Barrel” are landing good numbers of lake trout when using cowbells and spin-glo’s off the bottom. Chinook were hitting meat rigs and spoons 90 to 120 feet down in 180 to 250 feet in the early morning. Boats were heading straight out and north of the port.
Portage Lake: Bass anglers are picking up largemouth along the edge of the weed beds and the deeper drop-offs throughout the day. Panfish including perch were hitting on worms off the piers and docks and also in 18 to 22 feet.
Manistee: Boats are everywhere but the common fishing was 60 to 130 feet down in 80 to 200 feet. The average was between one and three fish for a few hours on the lake.
Ludington: Had no thermocline so boat anglers were traveling all over to find fish. A few charters came in with Chinook and steelhead. Most were fishing 60 to 80 feet down in 120 feet about six miles south to the “Project” or 60 to 120 feet down in 80 to 200 feet up near Big Sable Point. Some caught fish straight out from the pier in 100 feet. Cut bait seemed to be working better than spoons or plugs.
Pentwater: Was somewhat slow as the fish were scattered. Once those trolling found fish they did manage to catch trout and some salmon. They are using spoons, flies, copper and meat rigs and the hot colors were green and blue. Orange was a good color for steelhead. Try 50 to 60 feet down in 100 to 150 feet.
UPPER PENINSULA
Keweenaw Bay: Anglers are picking up a mixed bag in the early morning from 5 a.m. to 9 a.m. when trolling 25 to 35 feet down in 35 to 50 feet between the Baraga Marina and the Head of the Bay. They caught Chinook, coho, splake, lake trout and browns. Those fishing in the evening between 7 p.m. and 10:30 p.m. caught Chinook, coho and lake trout from the red can south of Sand Point and north towards Old Mission 30 to 50 feet down in 40 to 70 feet. Anglers are also seeing baitfish. Lake trout and coho were caught by those trolling or jigging from Hermits Cove south to 7-Mile Reef and off Big Louie’s Point. Those trolling 1.8 to 2.5 mph caught coho and lake trout. Those jigging were out in 180 to 260 feet off Big Louie’s. Lake trout were caught near the South Portage Entry as well as between the lighthouse and the Mud Banks in 60 to 90 feet.
Little Bay De Noc: Walleye anglers reported fair catches in the northern Bay with the Second and Third Reefs producing fish in 10 to 20 feet with crawler harnesses or stick baits at night. Excellent catches were reported south of the Ford River near No-See-Um Creek when using crank baits or stick baits in 16 to 20 feet. Most of the walleye here were bigger ranging four to eight pounds. Good catches of perch were reported between First and Second Reefs with minnows in 13 feet, off the Escanaba River in 20 to 25 feet and south to Portage Point fishing 10 to 18 feet down along the break with minnows or crawlers. Walleye anglers were also catching a lot of pike. Salmon anglers reported spotty catches out by the Ford River Buoy and just northeast of it when trolling spoons 30 to 60 feet down in 70 to 110 feet. The best smallmouth fishing was just south of the Ford River near Round Island when casting plastics in 12 feet.
Big Bay De Noc: Had fair to good walleye catches with those fishing well into the night reporting the best fishing. Most are trolling stick baits in 10 to 22 feet between Stoney Point and Kates Bay. Smallmouth anglers reported good catches around St. Vitals Island in 10 to 14 feet, Kates Bay in 12 feet or around Ansell’s Point in 14 to 18 feet when casting plastics and spinners or jigging with crawlers. Salmon anglers off Fairport did best at dusk. Those fishing during the day caught mostly lake trout. Many have traveled south to St. Martins Island where good catches of Chinook were reported 40 to 60 feet down in 80 to 120 feet.
Marquette: The Upper Harbor at Presque Isle Marina remains closed for renovation so the Lower Harbor is the main public launch at this time. Most are targeting lake trout with some using high-lines for a possible salmon. Success has varied with some managing to get a limit of lake trout while others caught nothing or only a few. Many are heading north and east and fishing the “white rocks”, Little Presque Isle, Partridge Island, the “Sand Hole” east of Marquette or the “Humps” out near Granite Island. Fish were caught flies and spoons tipped with cut bait in 140 to 180 feet. A few coho were caught off the Lower Harbor area. Those jigging in 50 to 80 feet near the reef out by Stannard Rock had good success.
Big Shag Lake: The boating access site located off Marquette County Road 557, along Knudsen Road will be closed beginning Monday, August 17 through Friday, August 21 for installation of a new concrete ramp. There is no alternate boat launch in the area.
Au Train Lake: Fishing improved slightly with several large smallmouth bass up to 20 inches and 4 pounds caught and released. A few more legal pike were also caught. Bass and pike anglers are casting spinners and small crank baits. Those targeting perch are using worms or small spinner rigs but most of the fish were less than 8 inches. Walleye fishing improved with a couple more legal size fish caught when trolling crawler harnesses and crank baits. Schools of minnows and small perch were seen near shore. The weed beds are dense. Surface water temperatures were right around 70 degrees.
South Manistique Lake: Water levels are down and lake temperatures are warm. Continue to fish deeper than usual for walleye and perch. The walleye were scattered but north of Norton Island continues to be the hot spot. On windy days, try drifting crawler harnesses with bottom bouncers along the deeper parts. On the calm days, use the same setup with pink blades and purple beads for monster perch. Pike fishing remains hot.
DeTour: Was producing a few more steelhead, Chinook and Atlantic salmon in the five to eight pound class. Anglers are trolling upstream of the lighthouse with 5 color lead core and three inch spoons for Atlantic and steelhead. Blue, white and chrome colored spoons worked best. Lake trout fishing was excellent for those trolling from the green buoy west of the lighthouse and back to the red buoy on the east side. Use chrome spoons 35 to 40 feet down in waters over 80 feet deep.
Drummond Island: Walleye fishing slowed in Scott Bay. Those trolling early morning and late afternoon caught a few along the west side of Rutland Island in 12 to 14 feet. In Maxton Bay, anglers are drifting and jigging crawlers in eight to 10 feet from Bay Island east to the old Drummond Island Sportsmen’s Club. Northern pike fishing was fair on the southeast side of Grape Island when trolling or casting chrome spoons with red eyes in six to eight feet along the weed beds. Those fishing the mouth of Harbor Island caught sunfish and rock bass in three to five feet.
Cedarville and Hessel: Pike fishing is good all throughout the Les Cheneaux Islands. Those casting in Moscoe Channel did best but fish were still caught by those trolling or still-fishing with chubs in all other locations. Perch fishing was excellent in Moscoe Channel and Hessel Bay. A few Chinook and lake trout were caught out of Hessel.
The Weekly Fishing Report is intended to give anglers an ”idea” of what is going on around the state. Updates for the report come from our DNR Fisheries Creel Clerks (seasonal staff) and field staff as well as DNR Conservation Officers working in in the field. General information when available can be found in the first paragraph for each section of the report. For those looking for specific information on a certain body of water or port, it is safe to say if a certain species is being caught in some waters in the area, more than likely they are being caught in all waters in that section of the state that have that species.
While we would love to include all waters and ports of the state that simply is not possible, especially with more than 11,000 inland lakes, the Great Lakes and thousands of miles of rivers and streams.