Field Trip: Electroshocking Native Brook Trout

When most people think of fishing on Cape Cod, they conjour up images striped bass and bluefish, open beaches and blue water. But Cape Cod also has several river systems that harbor wild brook trout, and state biologists are keeping a keen eye on them.
I recently had the opportunity to tag along with Steve Hurley on an electroshocking survey on the Coonamessett River, and I was delighted to find that its native brookies are thriving. Steve is the Southeast District Fisheries Manager for MDFW, and he has gained a wealth of knowledge on these majestic fish.


We entered the river, and Steve fired up “the shocker.” The device reminded me of the backpacks they wore in Ghostbusters.


Steve’s crew followed along behind him, towing a homemade, makeshift barge that carried their gear. Once a fish is succesfully shocked and netted, it is placed in the appropriate holding cooler on the barge.


When is fish is shocked, it is temporarirly stunned and rises to the surface. They recover quickly, though, so the team had to work fast to net the fish. The scene reminded me of my childhood, where one of my favorite pastimes was mucking about, catching critters with a dip net.


When they captured a larger specimen, they would quickly check it with a handheld scanner to see if it had been previously tagged. If it had, it went into a specific holding cooler. From left to right: Intern Mike Clark and MDFW technicians John Garofoli and Steve Wright.


Brook trout weren’t the only fish to show up in the survey. Alewives, a small chain pickerel, American eels, and several tesselated darters were also captured. All of the fish were released alive and in in good condition.


Several hundred feet up stream I saw a large fish hit the surface, and Steve began frantically yelling “Big net, big net, GET THE BIG NET!” His crew worked fast, and came up with our largest specimen of the trip.


After about 20 minutes, the crew set up camp on the river bank, and recorded data on the native trout they had captured.


A makeshift lab was set up. Any fish that had been previously tagged was carefully measured, which gives them a good overview of how fast they are growing. Steve noted that the growth rates in the Coonamessett River are quite impressive, and are close to those seen in the state hatcheries. This means the trout are feeding well, and the river offers suitable habitat for their survival. Eleven of the fish they caught that morning had been previously tagged.


This was our largest fish of the morning, it measured 15 inches. I was truly impressed to see a trout this size in the small river. This fine specimen was a native wild brook trout transplanted from the Mashpee River (it was 13.5 inches when it was transplanted on June 6, 2014 and grew 1.5 inches in just under a year). This trout was probably at least 4 years old which is a ripe old age for a wild brook trout.


Most of the trout captured were quite small, like this little guy, and measured under 3 inches. This is a good sign and means the fish are reproducing naturally.


Any fish larger than 3.5 inches was implanted with a miniscule chip. It’s length and chip number were carefully recorded, and they were then released.


Before getting rained out, Steve’s crew captured 41 trout, including 11 recaptures. They tagged 14 untagged trout and measured 16 young-of-year. I was amazed to see so many healthy fish in the river. I had always known they existed there, but never imagined there were so many.

It has the potential to be a true success story, mainly do to the hard work and vigorous efforts of Steve and his fellow biologists. Perhaps some day native brook trout will regain their foothold in Cape Cod’s freshwater rivers.

14 on “Field Trip: Electroshocking Native Brook Trout

  1. Warren Winders

    The best thing that we can do for native brook trout is restore their streams. Most of the Cooni has been reduced to an irrigation ditch designed to serve cranberry bogs. The bogs are no longer being used, and it is time to turn the Coonamessett back into the wild brook trout stream that it was before the bogs were put in along its banks. Where former bog streams have been restored, places like Red Brook and the Quashnet River, hundreds of wild brook trout are captured and tagged when Steve and his crew survey those streams. We know that the Coonamessett can be restored and we know how to make that happen. What is needed is for the town to commit itself to a proper restoration (rewilding) of the stream and its riparian lands.

  2. Geoffrey Day

    If you want to learn more about sea-run brook trout restoration work, years ago TU volunteers set up a new organization to further help Steve Hurley with PIT tagging and other support and to extend lessons learned on Red Brook and the Quashnet River on to other brooks and streams through out New England.

    Check out the Sea Run Brook Trout Coalition for more info.

  3. John Burns

    These little hidden gems are the seedbanks of genetic diversity for our native brook trout. It is so important to not only restore them, but to understand how the fish “use” them. Now my concern would be those who keep the fish they catch will all be going to Cooni to catch that 13″ fish and keep it. In some ways it would be nice to leave these secrets hidden, but how would fishers evolve to know that they need to leave the natives and keep only the stocked fish? Fishers, please be aware of this.

    1. Geoffrey Day

      John, some of these streams are catch and release, single hook only to project these native fish – however this type of protection is something that takes considerable political pressure to bring about, stream by stream, and the same goes for the controversial idea of eliminating stocking. Yet hatcheries and the fish they produce can also keep higher populations of fishermen away from these delicate streams, so ultimately we will always have to depend on hatchery fish in certain easy-access, high traffic areas.

      I’m not sure what the status is on the Coonamesset and I’ll see if I can find out.

      Turns out the stocked fish seem to get picked off easily by herons, cormorants, ospreys and other predators where the natives seem to be able to evade most of this type of predation. Studies show that once a healthy stream is no longer stocked, the natives have a much better time growing and thriving in a system – so maybe people can also help out by advocating areas where stocking does not occur.

  4. Geoffrey Day

    Here’s a few ways to get involved:

    Volunteer with TU’s SE MA or Cape Cod Chapter or any of the local Watershed Associations. They can always use the help and it is a great way to be on-the-ground with these efforts. They have regular work days, planning meetings, fundraisers, and much of the ground breaking work was accomplished by TU volunteers and various partners that joined with them through questions that turned up during work projects.

    Or of course you could support sea-run brook trout by becoming a member of SRBTC, joining the mailing list, joining the Facebook page, purchasing a print, becoming a donor, getting involved at the board level, etc.

    SRBTC’s resources go to funding scientific research and habitat restoration from Connecticut to Maine.

    SRBTC has been a key supporter in financing Steve Hurley’s work. Recently SRBTC assisted with paying for temperature monitoring systems, solar panels, batteries and other support equipment to power the fish tracking equipment.

    Other projects include video tracking, microchemical analysis, and understanding what factors contribute to brook trout running to the sea.

    Check out the site for more information.

  5. joe

    Great article and great work! Im pretty sure that was a grass pickerel though

  6. Tucker Simonsen

    Very cool! I recently posted a story about fishing for wild brookies in tiny streams on Cape Cod on my blog,!

  7. Dave Vosgien

    I saw brookies in the Pamet River years back and wonder if a survey was done there recently.

    1. peter

      Has anyone considered checking the Pamet river. Back in the early 70’s I caught some big (2 to 3.5 lb) brookies there. I have not fished the Pamet since the early 80’s but there were still some natives there. I caught some as small as 4inches and as big as 15 inches.

  8. Geoffrey Day

    Hi — Steve Hurley has been stocking the Pamet for years with brook trout. There may be some small reproduction – but if Steve is consistently stocking – there is a reason.

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