Short answer: yes, but far less often than the bait shop would suggest. When Massachusetts biologists sorted the stomachs of striped bass caught from June through September, 1997 to 2000, American eel turned up in one region of three, Nantucket Sound, where it made up half of one percent of the diet by weight. On the North Shore and in Cape Cod Bay they recorded none.
That sits oddly beside the live eel's reputation as the big-fish bait. Both can be true, and the gap between them is the useful part.
What the stomachs held
Nelson, Chase and Stockwell collected 3,006 striped bass of about 11 to 46 inches and found food in 1,720 of them. By share of total prey weight:
| Prey | North Shore | Cape Cod Bay | Nantucket Sound |
|---|---|---|---|
| American eel | none | none | 0.5% |
| Menhaden | 22.6% | 17.2% | 5.5% |
| Sand eels (sand lance) | 1.3% | 15.8% | 13.9% |
| All fish | 50.4% | 57.9% | 40.3% |
In Nantucket Sound, where 220 stomachs held food, eel was 0.3 percent of prey items by count and turned up in fewer than 1 in 100 of those stomachs.
A second, newer look found none at all. Murphy, Nelson and Grabowski caught 158 bass of 16 to 44 inches on rod and reel around Salem Sound from 2012 to 2016. Their stomach table runs from sand lance to mackerel to lobster, and it has no eel in it.
One clarification, since the table has two kinds of "eel" in it. Sand eels are not eels. They are sand lance, a different family of fish, and in Cape Cod Bay and Nantucket Sound they carried roughly 30 times the weight American eel did anywhere. If a Massachusetts striper's summer diet has an eel-shaped staple, it is the sand eel.
Why the eel might be missing
Three things about how those fish were collected work against seeing eels.
They are summer fish. Sampling ran June through September. The eel movement anglers tie to big bass is the run of adult eels downriver toward the sea, and most of that, where it has been tracked, happens in fall (below). The surveys stop just as it would be starting.
They are morning fish. Between 77 and 90 percent of the bass, depending on region, were caught between 6 a.m. and noon. Eels move in the dark. A stomach opened at mid-morning holds what that fish ate recently, and nobody in this study was sampling the night.
Big fish were often empty. Among bass over about 27 inches, only 17 to 38 percent of stomachs held anything, against 39 to 53 percent of smaller fish. The fish most anglers mean when they say "eel fish" are the ones the stomach record sees least.
One more wrinkle: the authors threw out anything they identified as their own sampling bait, and the paper does not say which baits were used.
When eels actually move
We could find no published count of when adult eels leave Massachusetts rivers. The best-measured American eel runs we found are farther away.
On the Shenandoah River in Virginia and West Virginia, Sheila Eyler radio-tagged 145 large eels and tracked them from 2007 to 2010; 96 moved downstream past at least one dam. Nine in ten of their downstream moves came between sunset and sunrise. Two-thirds came between September 15 and December 15, and there was a second peak in spring. What explained the timing was river flow, rises in flow, and water temperature. Moon phase did not.
On North Carolina's Roanoke River, a study of tagged eels in a reservoir from October 2019 to March 2023 found departures tied to time of day, rainfall, and changes in lake level from the dam's power operations.
Closest to us in setting, Carr and Whoriskey tracked silver eels from the Magaguadavic River in New Brunswick out through the coastal zone to the Bay of Fundy and linked their coastal movements to tides and light levels. The summary we read does not say which tides or how dark.
Put together: a migration that runs mostly in fall and mostly at night, tied to rising water in the rivers, that the Massachusetts stomach studies were never positioned to see. Whether big bass key on it here is a fair question. We found no published October or November stomachs for big Massachusetts bass, so the fall eel-and-striper link is an inference from timing, not a measurement.
Why the eel catches anyway
A bait's track record measures which fish bite it, not what fish eat. The fish that takes your offering is a filtered sample: the one willing to eat right then, in front of you, on that presentation (more in the fish you catch is the hungry one).
Several things about an eel have nothing to do with the menu. It stays alive on a hook for a long time. It swims on its own, so the angler does not have to supply the action. And it is mostly fished at night, by people who are after big fish, in places they chose because big fish have come from them before. Each of those can raise the catch without saying anything about what striped bass had been eating.
That is our reading, not a measurement. Nobody has put eel catches and stomach contents from the same Massachusetts fish side by side.
What to do with it
Inference from the studies above, not a tested rule:
- Fish eels for what they do on a hook. In the summer water that has been measured, Massachusetts bass were eating menhaden, sand eels and crabs (see do striped bass eat crabs). An eel works without being on that list.
- If you want to fish an eel run, think darkness and rising rivers. In the best-tracked American eel run, flow and temperature explained the timing and moon phase did not. River mouths on fall nights after rain are where that points, though no one has timed a run here.
- Do not read a good eel night as a diet report. It tells you the bait and the bite were right. It does not tell you bass were full of eels.
How StripedLines uses this
StripedLines is built for striped bass. The app can suggest eel as the bait to match at night in estuaries, back bays, harbors and rivers in the warmer months. It does not try to time the fall eel run: the dark, rainy fall nights are yours to call.