Central Maine Fishing Report: September 4, 2008
A few years ago I reported on a project that had great potential for fulfilling an important goal of our Department, 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 there for those who come after us.” I’d like to take this opportunity to bring you up to date on the status of that project.
A tributary to Pitcher Pond crosses Route 52 in the town of Lincolnville. In the fall of 2003, the Maine Department of Transportation replaced a failing “perched culvert” at that stream crossing. A perched culvert, you may recall, has a drop in elevation at its outlet. 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; that is, alleviating the drop. Nevertheless, the elevation difference from the upstream to downstream ends required a slope in the culvert 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 stocking of brook trout fry.
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 long time resident that 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 4000 feet.
Mrs. Miller told me that in a 1954 hurricane, a flood washed out the former stone-cribbed crossing. The culvert replaced by MDOT in 2003, 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. 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 Sucker Brook, a tributary to the pond, has a natural brook trout fishery that could allow some migration of trout into nearby Rollins Brook.
On June 7, 2004, the Department stocked 1,000 Maine Hatchery strain brook trout in Rollins Brook ranging from 3 to 3.5 inches long. On June 9, I went back to the stream to ascertain the presence of brook trout above the culvert. I observed that the fry made it up through the culvert. Although numbers were not high, it did indicate that the brookies could negotiate the incline in the culvert.
On Sept. 22, I returned to Rollins Brook to further document fish movements. 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 on June 7 or migrants from the pond? By all indications, such as deformed pectorals and shortened opercula’s (a commonly observed phenomena in hatchery fish), they were the survivors of the spring stocking of brook trout fry. The fish ranged from 4.5 inches to 6.5 inches and exhibited robustness. No other fish species were found.
On April 22, 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 five years of age, as noted in Little Pond, Damariscotta) can survive in small brooks and are capable of migrating in some unusual conditions. In 2005, 2006, and 2007 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 naturally improve.
The most important finding from our observations is that in small streams that are otherwise suitable for brook trout but have barriers to upstream fish passage, the removal of any man-made barrier can greatly facilitate restoration of brook trout populations.
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 many 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.