Striped bass are by far the most sought-after and studied game fish on the East Coast—but that doesn’t mean we know everything about them. On the island of Martha’s Vineyard, the Wampanoag Tribe of Gay Head Aquinnah, in cooperation with the Marine Biological Laboratory of Woods Hole, have initiated a tagging project to monitor a population of adult stripers that have been spending the winter in Squibnocket and Menemsha Ponds. Squibnocket serves as the spawning and nursery grounds for a run of river herring managed by the Aquinnah Tribe, who want to know if the so-called holdover bass are impacting the herring population by preying on both the returning fish and the young-of-the-year juveniles.

In most parts of the striper’s range, the bass typically arrive after the herring have entered their natal rivers. However, the Squibocket fish are already lying in wait for the returning herring—and they are hungry!

Several times in the fall of 2023, a team led by Bret Stearns, Director of the Aquinnah tribe’s Natural Resources Department, gathered at the Squibocket herring run to corral and capture some of the resident stripers and implant them with special acoustic transmitters that would allow researchers to monitor their movements in the ponds. Helping the cause were staff from the Marine Biological Laboratory, which already has experience in implanting the rather bulky transmitters inside striped bass. The process involves sedating the fish in a cooler then transferring it to a special table while saltwater is passed over its gills to keep it alive. An incision is made in the fish’s belly, into which the transmitter is inserted. Finally, the incision is sewn shut and the bass carefully revived in the creek.

Over the span of about a month, the researchers implanted 20 stripers with transmitters. All of them survived the operation, and data showed that 19 of the 20 stripers remained in the area through the winter.

How many stripers spend the winter in the ponds? Last year, at least 125 fish were counted on underwater video cameras, prior to the arrival of any migratory bass, but it’s suspected that the actual number of holdovers could be as high as 300.

It’s important to note that stripers have probably overwintered in the salt ponds since the ice age, so it’s not fair to blame them for the decline in the local herring population. It’s more likely that commercial fishing pressure in the form of midwater trawling, as well as the vagaries of climate change, are having a much larger impact.

So, what’s next for the tagging study? Both the Aquinnah and Woods Hole researchers will continue to tag fish and monitor their movements using a greater number of receivers. Ultimately, they will try to learn why the bass are overwintering in the ponds, at what depth they are holding, and if they might be spawning there in the spring. Stay tuned!