Sand Eel: Rare Underwater Footage Reveals Striped Bass, Bluefish, and Dogfish Hunting Cape Cod’s Most Important Baitfish

The smell hit me first.

Standing on my boat the morning of June 26th, 2023 at Stellwagen Bank, I could actually smell the whales' breath—that distinctive fishy, musty odor that tells you humpbacks are surfacing way too close for comfort. Thick fog had already forced me to abandon my plans to film giant bluefin tuna, and now these massive mammals were breaching and feeding way too close to my boat. When you can smell a whale's breath, it's time to leave.

I turned around and headed to Provincetown instead.

That decision led to some of the most revealing underwater footage I've ever captured off Cape Cod. Setting up a drift off Provincetown's coastline in late June, I dropped my GoPro camera to the bottom and let it film.

What I found when I reviewed the footage was so cool: striped bass, bluefish, and dogfish swimming together amongst sand eels in just 20 to 35 feet of crystal clear water.

Two years ago, I published that footage on My Fishing Cape Cod with minimal context. The video got tremendous engagement, but I never told the full story.

With the boats put away for winter and the vast majority of stripers long gone south, now feels like the perfect time to share what I learned about sand eels, why Provincetown's underwater geography makes it a sand eel and striper hotspot, and what this footage reveals about how gamefish hunt one of the most critical baitfish in our waters.

What is a Sand Eel?

Sand eels aren't actually eels at all—according to some quick research I did on Wikipedia, they're slender fish from the Ammodytidae family, most commonly from the genus Ammodytes here on Cape Cod. They're also called sand lance, and the terms are used interchangeably in the fishing community.

These fish are typically 4 to 7 inches long on Cape Cod, though they can grow up to 10 inches. They have a distinctive pencil-thin profile with a pointed snout, silver sides, and an olive to tan back. Their most unique characteristic is their defensive behavior: when threatened, sand eels burrow headfirst into sandy bottoms, disappearing completely within seconds.

Sand eels feed primarily on plankton and tiny crustaceans, filtering them from the water column. They school in massive numbers, sometimes creating clouds of baitfish that stretch for hundreds of yards.

These schools are the foundation of the Cape Cod food web. Striped bass, bluefish, bluefin tuna, cod, summer flounder, and virtually every gamefish that swims in our waters feeds heavily on sand eels during peak season.

Why Provincetown Is Sand Eel Central

Here's what makes Provincetown special for sand eels: the underwater geography.

Centuries of powerful currents have carved a dramatic drop-off along the Provincetown coastline. The shallow shelf extends from the beach before plunging to over 100 feet deep. This unique topography creates a very unique set of conditions for sand eels, mackerel, stripers and countless other fish and marine mammals.

On the shallow shelf—where I filmed the following footage in 20 to 35 feet of water—the sandy bottom provides ideal habitat for sand eels to burrow and feed. The strong currents moving across this shelf create the gravelly sand substrate that sand eels prefer. I would imagine that these same currents likely concentrate plankton along the shelf, stacking up food in predictable areas where sand eels may congregate.

What the Underwater Footage Reveals

When I reviewed the footage, I saw something unexpected: all three species in the same place at the same time.

Striped bass, bluefish, and dogfish were all cruising through the same sand eel school. I'm used to seeing stripers and blues together in my underwater footage—that's common enough. But seeing dogfish mixed in with them? That was a cool surprise.

What struck me most was how relaxed it all seemed. These weren't frenzied attacks or coordinated hunting strategies. The predators were just there, moving through the massive concentration of sand eels. Stripers would occasionally charge and scatter the school. The bluefish cruised and the dogfish patrolled the bottom

Multiple predators recognizing the same opportunity and taking advantage of it. The sand eel concentration was so thick that there was plenty to go around. Each species could hunt in its own style without getting in the way of the others.

What you can also see in the footage is the sand eels' defensive behavior breaking down. They start in a tight school, a silver mass moving as one. When an attack occurs, individual sand eels peel off, trying to reach the bottom. Some make it and burrow. Others don't. The ones that succeed may still get dug out of the sand by stripers seconds later.

This is the reality of being a sand eel: you're one of the most hunted fish in the ocean. Your survival depends on numbers—overwhelming predators with sheer abundance so most of the school survives even if individuals don't.

The Technical Challenge

Sometimes I wonder why I keep dropping cameras to the bottom when the success rate is so low. The answer: those few seconds of usable footage can teach us more about fish behavior than hours of conventional fishing ever could.

My filming technique on this day was straightforward but requires patience. I used a GoPro camera in waterproof housing, in a Troll Pro case, weighted to sink to the bottom, and tied to my Penn 80 giant tuna reel and rod.