Stripers Push the Merrimack as the Herring Run Peaks

What's Biting

What's Next

The full moon peaking tonight through Sunday sets up prime low-light feeding windows for stripers along the Merrimack. Big fish, including the 40-inch class reported by Surfland Bait and Tackle via The Fisherman — South Shore MA to ME, tend to feed more aggressively and push into shallower lies under a full moon, especially during the dark hours surrounding high tide and on the outgoing flow that follows. If the herring run stays strong through early June as expected, the striper bite should remain productive on the river for at least another week to ten days. River herring are the engine driving this bite; once those schools begin to thin, the larger bass will scatter and become more target-specific.

At 540 cfs (USGS gauge 01073500), the Merrimack is running at a moderate, fishable level. Flows favor wading anglers who can work seams below riffle drops, around bridge abutments, and along current edges where herring stack. If rain enters the region mid-week and the gauge rises meaningfully, fish will temporarily pull off structure, but a subsequent drop back toward current levels should concentrate them again at familiar holding spots.

On Lake Winnipesaukee, no source reported specific conditions this week. Seasonal logic points toward smallmouth bass entering the post-spawn transition. Fish that were locked on gravel and rocky shallows in 3 to 8 feet of water through mid-May will begin scattering toward mid-depth points, humps, and rock piles in the 10- to 20-foot range over the next one to two weeks. Tactical Bassin's post-spawn breakdown recommends targeting isolated offshore structure and using the wind to drift open flats, a proven approach for lake smallmouth as they recover from the spawn. Finesse presentations (dropshot, neko rig) and moderate-reaction baits like chatterbaits are worth rotating through when fish are not locked on a single depth.

Lake trout at Winnipesaukee are approaching the point where surface warming pushes them deep reliably. This weekend may be one of the last good windows for shallower jigging before a downrigger becomes necessary for consistent contact.

Context

Late May on the Merrimack River has historically marked the heart of the anadromous run, with striped bass pushing upriver on the heels of river herring. The timing described by Surfland Bait and Tackle in The Fisherman — South Shore MA to ME, herring 'very much on' and stripers to 40 inches in the river, is right on schedule for this time of year. In most seasons the herring peak falls between mid-May and mid-June, and the striper action follows it closely as fish locate bait concentrations below dams and at natural pinch points in the river.

At 540 cfs, the Merrimack is running on the lower side of typical late-May flows, which in wet years can push well above 1,000 cfs from snowmelt and spring rain. Below-average flow is generally favorable for anglers: fish concentrate in predictable runs and pools rather than spreading across flooded banks, structure becomes more defined, and wading access opens up considerably.

For Lake Winnipesaukee, no source in this reporting cycle provided direct comparative data. Historically the lake's smallmouth fishery is near its seasonal peak right now, with fish transitioning out of spawn and into post-spawn patterns around Memorial Day weekend. The full moon at the end of May often coincides with the tail end of the spawn push for Winnipesaukee smallmouth, making this a transitional week where some fish are still shallow and others have already moved. Lake trout historically retreat to deeper, cooler water by early June, so this window represents a meaningful seasonal marker. Anglers who have been finding lakers on structure shallower than 40 feet should begin extending their range downward. No source this cycle corroborated specific Winnipesaukee laker depth, so treat that guidance as seasonal context rather than confirmed live intel.