A few years ago I reported on a project that had great potential for fulfilling an important goal of the Maine Department of Inland Fisheries and Wildlife, namely "to provide anglers with the most opportunities for the types of fishing they want, while ensuring that these same fish resources are going to be here for those who come after us." That project is progressing.

A tributary to Pitcher Pond crosses Route 52 in the town of Lincolnville at the eastern edge of Region B in central Maine. In the fall of 2003, the Maine Department of Transportation replaced a failing culvert at that stream crossing. A perched culvert has a drop in elevation at its downstream mouth. If the drop is sufficiently high, fish are unable to pass through the culvert to upstream habitat. The new culvert was installed with an embedded outlet, without a drop in elevation at its mouth.

Nevertheless, the elevation difference from the upstream to downstream ends required a slope in the culvert about halfway through so that streambed movement could be avoided. I was skeptical of the ability of brook trout to negotiate the slope, but told the DOT environmental reviewer the site would be a good place to evaluate fish passage with a brook trout fry stocking.

Townline Brook, the name I gave the stream at the time in order to satisfy stocking records, is really Rollins Brook, according to Peg Miller, a longtime resident who owns land abutting the stream. She indicated that the stream dries up in some years.

The brook is designated as an intermittent stream on the area's topographical map. According to the map, the total length of the stream is about 4,000 feet. Miller said that in a 1954 hurricane, a flood removed a stone-cribbed crossing and the perched culvert, and the culvert replaced by MDOT last year was the result. She couldn't recall any angling in the brook in her lifetime. Since 1954, the stream was most likely waterless in many summers, eliminating any fish populations above the perched culvert.

The vertical barrier formed by the perched culvert prevented re-colonization of the brook from downstream of the culvert. Prior to 1954, we do not know if a barrier was present at the crossing, but there is free access from Pitcher Pond to the present crossing. Pitcher Pond has a warm-water fishery but has a known natural brook trout fishery in another tributary at Sucker Brook that could allow some occasional migration of trout to nearby Rollins Brook.

In June of 2004 we were able to stock 1,000 Maine Hatchery-strain brook trout that were about 3 to 31/2 inches in length. Days later, I went back to the stream to ascertain the presence of brook trout above the culvert. I did document that the fry made it up through the culvert within a week and, although numbers were not high, it did indicate that the brookies could negotiate the incline in the culvert.

Late that September, I returned to Rollins Brook to document what had occurred. The first brook trout was found immediately above the culvert, and I encountered other brook trout at likely pools for approximately 2,000 feet above the culvert. Were they the unmarked brookies stocked in June or migrants from the pond? By all indications they were the survivors of the fry spring stocking of brook trout in the previously fishless brook. The brook trout ranged from 41/2 inches to 61/2 inches and exhibited robustness. No other fish species were found.

In April of 2005 I returned to Rollins Brook to evaluate over-winter survival of the brook trout. We captured six 5- to 7-inch brook trout from just above the culvert to about 400 feet upstream.

Although 2004 was unusual with respect to cool temperatures and higher than normal water flows, there are some things we can gain from our observations. For instance, Maine Hatchery-strain brook trout (which can survive to 5 years of age, as noted in Little Pond in Damariscotta) can survive in small brooks and are capable of migrating in some unusual conditions. During the September 2004 evaluation, when in my judgment it was pretty certain that I would not find fish above what I thought was a barrier, I found another trout in the next good-looking pool. Further upstream I finally encountered a barrier where the brook disappeared underground.

In 2005 and 2006 our investigations and angler reports indicated that brook trout are now using this small watershed. In other work around the region our brook trout stream monitoring efforts have indicated that these types of small watersheds experience a rebound in brook trout populations when water flows are naturally increased, thus allowing native fish to re-colonize barren streams that periodically experience water deprivation.

The most important finding from our observations is that in small streams that are otherwise suitable for brook trout, but where we have barriers to upstream fish passage, the removal of any man-made barrier can greatly facilitate restoration of brook trout populations whether through natural re-colonization or through stocking. In many towns throughout Maine, culverts have been installed that prevent fish passage. Some of these were placed many years ago and the natural condition of the stream has passed out of local memory.

Ultimately, this often results in locals accepting that the stream is devoid of brook trout. Since Maine has numerous miles of small streams, all of us need to be vigilant in pointing out to town and state officials that if a culvert is perched and preventing fish passage, this is an unacceptable installation and should be remedied.

--Bill Woodward, Assistant Regional Fishery Biologist