Short answer: yes, but to a striper "herring" means two different fish on two different calendars. Atlantic herring were an early-summer meal for young bass north of Boston. In one Massachusetts reconstruction they were nearly a third of what 3-year-old bass ate in June and July, and they were missing from the August and September diet of bass aged 3 to 7. River herring (alewife and blueback) were about 1 percent of the summer diet coast-wide, but in the river during the spring run they were a regular meal for big fish.
Two herring
Atlantic herring is a sea fish. Alewife and blueback herring, the river herring, are anadromous: they live at sea and run up rivers and streams to spawn in spring. Biologists keep them apart, and the stomach studies below do too.
What the stomachs held
Nelson, Chase and Stockwell of the Massachusetts Division of Marine Fisheries collected 3,006 striped bass stomachs from June to September, 1997 to 2000, and 1,720 of them held food. Their summary table, by share of diet weight:
| North Shore | Cape Cod Bay | Nantucket Sound | |
|---|---|---|---|
| Atlantic herring | 5.8% | 0.1% | none recorded |
| River herring | 0.7% | 1.3% | none recorded |
| Herring-family fish not identified | 2.4% | 2.1% | none recorded |
| Menhaden, for scale | 22.6% | 17.2% | 5.5% |
| Stomachs with food | 886 | 614 | 220 |
Atlantic herring turned up in 3.4 percent of North Shore stomachs with food. The unidentified row could be any member of the family, menhaden included. South of the Cape, no herring of either kind made the table.
Early summer, not late
The summary hides the season. Nelson's team also grouped North Shore stomachs by months, habitat and fish size. In three of the four groups that included June and July, Atlantic herring was 6 to 8 percent of the diet; in the fourth it was 0.6 percent. In both August–September groups it was absent, and menhaden took over.
A follow-up by the same team (Nelson 2006) rebuilt the North Shore diet by age from those stomachs:
- 3-year-old bass, June–July: 30.8 percent Atlantic herring. August–September: none. Those fish averaged about 2 pounds (946 g), and 70 of their stomachs held food.
- Ages 3 through 7: no Atlantic herring in August and September at all. Age 8 went from 14.5 percent to 0.6.
- Size: the herring eaten by 3- and 4-year-olds averaged about 5 grams, under a fifth of an ounce, so young herring. Ages 6 to 8 averaged 106 grams, about 3.7 ounces.
The authors call their herring estimates low in precision, and the age-8 group rests on 31 stomachs with food. Their explanation for the pattern: young Atlantic herring are abundant near shore in the Gulf of Maine in spring and early summer, then move to deeper water offshore in summer and fall.
Two other studies point the same way. In 1999, Ferry and Mather fly-caught 797 bass in 13 Massachusetts estuaries, most of them 15 to 19 inches, and pumped their stomachs before release. In spring (May–June), estuary bass on the North Shore and the Boston–South Shore ate mostly herring-family fish, which the authors describe as mostly juvenile Atlantic herring (from vertebra counts in two of the estuaries). Less than 5 percent of that herring-family share was river herring. By autumn (September–October) the same estuaries' bass were eating mostly young menhaden.
Around Salem Sound from 2012 to 2016, Murphy, Nelson and Grabowski found Atlantic herring at 4.2 percent of the diet by weight in 158 rod-caught bass: 14 herring in 6 stomachs. They found no river herring. Mackerel led that diet at 42.8 percent.
River herring: small on the coast, big at the run
Coast-wide, alewife and blueback were 0.7 and 1.3 percent of the summer diet. But Nelson's June–July groups tell a different story. Bass of about 17 to 25 inches on North Shore rocky shore (239 stomachs) carried 6.3 percent river herring, and a mostly June–July estuary group in Cape Cod Bay (159 stomachs) carried 5.3 percent. For 3-year-olds on the North Shore in June and July it was 10.3 percent.
In the river itself, the number gets large. Davis, Schultz and Vokoun studied the Connecticut River above the head of tide during the spring runs of 2005 to 2008. In 642 stomach samples taken in May and June, blueback herring turned up in 19 percent of bass from 25 to 39 inches, and smaller bass of about 16 to 22 inches ate them only now and then. The authors estimate those river bass ate about 395,000 blueback in a spring, with a 90 percent range of about 178,000 to 791,000.
When the run happens is a water-temperature question, not a date. We covered that in the herring run is not a date.
The fall herring gap
The fall sea-herring story, big bass on adult herring in October and November, is a different question, and the stomachs above cannot speak to it. Nelson's sampling stopped at the end of September, and 77 to 90 percent of those bass were caught between 6 a.m. and noon. Ferry's autumn sample ran into October, but it was 15- to 19-inch fish in estuaries. We found no Massachusetts stomach study of big bass on the open coast in October or November.
That is an evidence gap, not a debunking. Nobody has measured it here.
What to do with it
Inference from the diet studies, not a tested rule:
- June on the North Shore, think small herring. The Atlantic herring young bass ate averaged under a fifth of an ounce.
- By August, switch. Atlantic herring dropped out of the late-summer North Shore stomachs, and menhaden carried the diet. See menhaden are an autumn bait.
- In spring, the run is the place. River herring were a small share of the coast-wide diet and a regular meal for bigger bass in the river.
- In Nantucket Sound, no herring of either kind made Nelson's table.
- For fall sea herring, your own log is the best record there is. Note what the fish cough up.
How StripedLines uses this
StripedLines is built for striped bass. The app treats the spring river-herring run and fall sea herring as different things. In spring, river mouths near mapped herring runs can rate higher as the coastal water warms. In October and November it can name sea herring as the likely bait in cold, deeper ocean water; no Massachusetts stomach study covers big bass on the open coast in those months, so that label comes from the calendar, not measured diets.