What Lake Erie predators actually eat

Most Steelhead Alley anglers know steelhead eat baitfish. Walleye eat shiners. Smallmouth eat crayfish. That's not wrong, but it's not specific enough to actually shape what you tie on. This briefing pulls the real numbers out of state-agency and multi-agency studies and tells you what's known, what's been changing, and what nobody's measured yet.

The headline: steelhead really do eat emerald shiners

The Great Lakes Fishery Commission's Coldwater Task Group published an analysis of 349 Lake Erie steelhead stomachs collected across the major basins. Two hundred and fifty of those stomachs -- 72 percent -- contained at least one food item.

Rainbow smelt comes in second at 19.75% of West Central biomass overall (about 24% in August). Round goby and juvenile yellow perch also show up in stomachs, but not at the shiner-group volumes.

What this means in practice: a white-silver shiner imitation isn't a "maybe they'll hit it" pattern. It's matching the single largest component of Lake Erie steelhead diet over a five-month window in the most-studied basin. Woolly buggers, Clousers, Zonkers, and dedicated emerald-shiner-pattern streamers all key on this evidence.

Source: GLFC Coldwater Task Group, "An Analysis of the Diet of Steelhead Trout in Lake Erie" (~2004 final report)

The caveat: emerald shiner abundance is at decade lows

Here's where the "match the hatch" instinct gets complicated. The Great Lakes Fishery Commission's March 2026 Forage Task Group report documents that emerald shiner abundance has remained low for a decade. Multi-agency trawl surveys show shiner densities well below historical baselines.

What that means for anglers: the diet study tells you what steelhead key on. The abundance reports tell you that those forage schools are scarcer than they used to be. Don't assume a shiner-imitation streamer will outperform other patterns just because the diet evidence is strong -- if the river you're fishing doesn't have shiner schools at the moment, the fish aren't eating what they aren't seeing. Treat shiner patterns as one option in the streamer rotation, not as a default search pattern.

This is also why local intelligence (current river reports, recent bait observations, tributary-mouth scouting) still matters more than any general-purpose recommendation.

Sources:
GLFC, "Report of the Lake Erie Forage Task Group, March 2026"

The seasonal window for nearshore shiner-feeding

The New York State Department of Environmental Conservation's Lake Erie smallmouth bass fishing guidance documents a specific window. During April and May, emerald shiners move into tributaries and harbor areas because water temperatures rise faster than the open lake. Smallmouth bass actively feed on these shiner schools in nearshore zones during this period.

NYSDEC explicitly recommends "woolly buggers and minnow patterns, especially emerald shiner patterns" for fly anglers targeting smallmouth on Lake Erie. This is one of the few angling-relevant fly-pattern recommendations that lives in a state-agency document rather than just angler literature.

The implication for steelhead anglers is narrower: the April-May nearshore/tributary shiner movement overlaps the tail end of the spring steelhead run in many Lake Erie tributaries, so lower-river or tributary-mouth shiner patterns are a defensible translation. That is an angling inference from NYSDEC's smallmouth guidance plus the GLFC steelhead diet study, not a separate steelhead stomach-sampling result for April-May tributary mouths.

Source: NYSDEC, "Smallmouth Bass Fishing On Lake Erie"

Size matters: what the shiner-imitation hook range should actually be

Atkinson, Desrosiers, Townsend, and Simon published a length-weight study of 400 emerald shiners from the Western Basin of Lake Erie in the Ohio Journal of Science in 2015. Their age-class breakdowns:

• Age 0 (young-of-year): males 15-33 mm total length; females 18-30 mm. Roughly 0.6-1.3 inches.
• Age I: males 39-78 mm; females 42-78 mm. Roughly 1.5-3.1 inches.
• Age II+ (adults): males 78-111 mm; females 81-108 mm. Combined Age II+ range 78-111 mm; approximately 3.1-4.4 inches.

Maximum recorded length in the broader literature: 13 cm (about 5.1 inches) per the USGS Nonindigenous Aquatic Species species profile.

For fly tying and lure selection, the 2.0 to 4.0 inch band is a practical imitation range that covers much of Age I and Age II+ together. The upper end (3.5 to 4.4 inch patterns) matches the documented Western Basin adult size class. Hook sizes 2 through 6 fit this translation range, but exact predator size-class selectivity still needs a separate diet study.

Sources:
Atkinson et al. 2015, Ohio Journal of Science 114(2)
USGS NAS, Notropis atherinoides species profile

The crayfish story: why a 50% diet component became 8%

This one's an evolving story with a Tier 1 number behind it.

The New York State Department of Environmental Conservation's 2024 Lake Erie Smallmouth Bass and Yellow Perch Diet Analysis sampled 25 smallmouth bass stomachs from the eastern basin in September 2023.

Post-invasion historical samples shifted hard toward round goby, with 73.3% occurrence. A separate Steinhart, Stein, and Marschall study of first-year smallmouth bass in New York Lake Erie waters found that 75% of the fish they consumed were round gobies during 1999-2001. Those are related but distinct measurements: 73.3% is the historical post-invasion occurrence figure in the NYSDEC summary, while 75% is the first-year-smallmouth fish-prey figure from Steinhart et al.

What this means for the crayfish-pattern fly box:

• Crayfish patterns still produce on Lake Erie smallmouth. The 8% / 6.8% numbers are non-zero and the historical 50% diet share didn't vanish overnight in the food web.
• Round goby is now the better-supported primary forage story for Lake Erie smallmouth in the sourced Eastern Basin late-summer evidence. A goby-imitation streamer (sculpin-style profile, mottled olive-brown coloring, weighted to swim near bottom) is probably the higher-percentage pattern for many Lake Erie smallmouth situations in summer.
• The two patterns complement each other -- crayfish in cobble/log-jam cover and along bottom transitions, goby imitation through structure edges and current breaks.

For Steelhead Alley tributary fishing, this also reframes the smallmouth-targeting moments during summer warmwater windows: the crayfish pattern that used to be the default is now a specialist piece, and the goby imitation should probably be in the box too.

Source: NYSDEC, "Lake Erie Smallmouth Bass and Yellow Perch Diet Analysis" (March 2024)

The Lake Erie crayfish species you might actually be imitating

When you tie on a crayfish pattern in Pennsylvania's Lake Erie watershed, the actual species you're imitating is most likely one of three native Cambaridae per a 2019 peer-reviewed reassessment by Allison, Khan, Lieb, and Loughman (Proceedings of the West Virginia Academy of Science). Their 54-site stream sampling found these most abundant:

• Cambarus robustus (Big Water Crayfish)
• Faxonius propinquus (Northern Clearwater Crayfish)
• Cambarus carinirostris (Rock Crayfish)

Additional native species documented in the basin: Faxonius obscurus (Allegheny Crayfish, found in one Elk Creek tributary and one Lake Erie tributary), Faxonius immunis (Calico), Creaserinus fodiens (Digger).

Invasive species collected: Procambarus acutus (White River Crayfish). The aggressive displacer Faxonius rusticus (rusty crayfish) is documented as cryptogenic in Lake Erie per USGS Nonindigenous Aquatic Species, meaning its origin/native status is uncertain and it has been observed to displace native crayfish where established.

For the angler, this matters in two ways:

1. Color and size: olive-brown 1.5 to 3 inch crayfish patterns in hook 4-8 are the angler-translation band we use for imitating this forage class. That is a practical fly-sizing convention, not a species-by-species body-length claim for every native PA Lake Erie crayfish.
2. Live-bait regulations: anglers using live crayfish bait should check the current state-specific rules before transporting or releasing any crayfish. Regulations and invasive-species lists change.

Sources:
Allison et al. 2019, Proceedings of the West Virginia Academy of Science
USGS NAS, Faxonius rusticus species profile
PFBC Aquatic Invasive Species program

Sucker spawn: when biology and angler practice are both right

White sucker (Catostomus commersonii) spawning is the biology behind one of the most consistently-fished egg patterns in Lake Erie steelhead fly fishing. The Ohio Department of Natural Resources' Life History Notes documents:

• Spawning April through early May.
• Spawning runs upstream at night on gravel substrate.
• 20,000 to 50,000 eggs per female.
• Young hatch and remain in gravel one to two weeks before migrating downstream at night.

What you can take from this as a steelhead angler:

• The 50 deg F water temperature is your Pennsylvania-sourced biological cue. When tributary water approaches that threshold in spring, sucker spawn becomes the most defensible egg-pattern moment of the year. Treat it as an approximate cue, not a precise switch that applies equally to every tributary.
• The Ohio April-early-May window and the PA early-May-early-June window are slightly different. This matters if you're fishing tributaries in both states across a single spring -- the egg-availability window staggers by latitude and watershed.
• Egg morphology: PFBC documents the eggs as tiny and slightly adhesive, with up to 50,000 per female and behavior that includes either adhering to substrate or drifting in the current. Cream, yellow, and peach pattern colors are the angler-tradition match; the cited PFBC text doesn't name a specific egg color, so the color choice is a translation heuristic, not a sourced biological claim.

An important honesty about steelhead-specific diet evidence: the GLFC 2004 steelhead diet study sampled stomachs primarily in July and August (East Basin samples ran August-September). That sampling window is after the April-early-June sucker spawning period. The study's absence of sucker spawn in steelhead stomachs is not evidence that steelhead don't eat sucker spawn -- it's evidence that nobody timed a study to capture the spring window in Lake Erie tributaries. The Sucker Spawn fly pattern's effectiveness for steelhead is well-attested in angler practice, but it doesn't yet have a Tier 1 or peer-reviewed diet study behind it the way the emerald shiner / steelhead connection does.

Sources:
ODNR, Life History Notes: White Sucker
PFBC, "PA Fishes" Chapter 12 Suckers (Family Catostomidae)

What's missing from the public science

This briefing is built on the best available Tier 1 state-agency and Tier 3 peer-reviewed sources we could locate. Several things you might want to know are not in the public record at search depth, and we won't fabricate them:

• Tributary-specific shiner-mouth aggregation timing. Nobody has published a study that says "the Chagrin mouth holds shiner schools in late October." Local guides and shop intelligence are still the source for that.
• Brown trout diet selectivity. The GLFC study covers steelhead specifically. Brown trout in Lake Erie tributaries presumably eat similar baitfish but the species-specific diet study isn't there.
• Current adult Lake Erie walleye diet. USGS has historical walleye diet studies from the 1959-1960 year-classes that document emerald shiner use; a contemporary adult-walleye diet study would close this gap.
• Steelhead crayfish-diet specifics. The GLFC steelhead diet tables don't appear to document crayfish at the level extracted in this briefing; a dedicated study would help.
• Tributary-specific steelhead sucker-spawn diet study. As noted above, sampling timing mismatch leaves this open.
• Wind-driven nearshore concentration patterns for shiners. Anglers know wind concentrates shiner schools to specific shore zones; the quantitative agency study to anchor that claim hasn't surfaced.
• Lake Ontario tributary applicability. This briefing focuses on Lake Erie because that's where the sourced studies are. Lake Ontario steelhead diet, sucker spawn, and crayfish dynamics likely differ and require separate citations.

If you have access to studies that close any of these gaps, send them to us.

Practical takeaways for the box

Reading the evidence above, the box assembly logic for Steelhead Alley becomes:

For Lake Erie steelhead in tributaries:

• White/silver shiner imitations (Zonker, Clouser, Sparkle Minnow, dedicated emerald-shiner streamers) in hook 2-6 -- matching the strongest sourced diet item, with 47.7% / 57.71% Tier 1 backing.
• Sucker spawn patterns when water approaches 50 deg F in the Ohio/PA spring window -- matching a known biological egg-availability cue even though steelhead-specific diet selectivity hasn't been peer-reviewed yet.
• Egg patterns generally (sucker spawn variants, Glo Bugs, Estaz eggs) for the spring window.

For Lake Erie smallmouth bass:

• Goby-imitation streamers (sculpin-profile, mottled olive-brown) -- matching the post-invasion dominant forage story, with round goby at 64.0% occurrence and 60.8% volume in the September 2023 NYSDEC sample, 73.3% occurrence in post-invasion historical samples, and 75% of first-year-smallmouth fish prey in the separate Steinhart et al. study.
• Crayfish patterns (Whitlock Near-Nuff, Clouser Crayfish, weighted Woolly Bugger in olive/brown) for cover edges and rocky substrate -- matching the still-present 8% diet share.
• Woolly buggers and minnow patterns (NYSDEC-recommended) during the April-May nearshore window -- matching the spring shiner-feeding behavior.

For Lake Erie walleye:

• Shiner-pattern streamers (white/silver) are historically supported by USGS Lake Erie diet research for young-of-the-year and 1959-1960 year-class walleyes. This is not a fresh current-adult or tributary-specific walleye diet claim.

For warmwater conditions (water 68-70 deg F or above):

• Shift away from steelhead/trout. Smallmouth bass, freshwater drum, and channel catfish become the ethical and productive targets per state-agency thermal guidance.

Why we're publishing this

SHA is building toward being the authoritative source for Steelhead Alley entomology and biology. That requires telling the truth about what's known and what isn't. Most fishing content makes confident claims about hatches and diets without citing the underlying research. This briefing cites real studies, distinguishes overall metrics from monthly peaks, distinguishes Lake Erie from Lake Ontario, distinguishes one basin from another, and explicitly marks the gaps where Tier 1 evidence does not yet exist.

If you fish Steelhead Alley, this is the evidence we'd want you to have before tying on. If you guide, this is the source list we'd want behind you.

Full source list

Continue learning

• The Steelhead Alley Seasonal Calendar -- the month-by-month rhythm tying forage visibility to the annual cycle.
• Inland Trout Near Steelhead Alley -- the inland-trout vertical opener for the summer window when steelhead are not in the tribs.
• Lake Erie Goby Takeover -- the round goby diet-flip narrative anchoring the lake-side forage picture.
• Steelhead Life Cycle -- the flagship steelhead biology pillar.