Title: Squaretails, Biology and Management of Maine’s Brook Trout

Author: Forrest Bonney

Copyright Date: 2007

Price: $10 at http://www10.informe.org/webshop_ifw/index.php?p=1859&c=12&storeID=2

ISBN-13: 978-0-9794363-0-7

Maine anglers and those who travel to the Pine Tree State in pursuit of trout have long been aware of the value of the brook trout fishery it provides.  Not until recently, however, has the unique worth of Maine’s wild and native brook trout populations been widely exposed.

Forrest Bonney’s new book, Squaretails, Biology and Management of Maine’s Brook Trout, comes at the heels of the Eastern Brook Trout Joint Venture, a collaborative project evaluating brook trout populations throughout their native range in the United States.  Preliminary results from the Joint Venture are showing that Maine represents the last stronghold for native brook trout, containing more brookies in their historic range than any other state.  A heightened focus on brook trout in Maine sets a perfect stage for Squaretails, where Bonney attempts to provide a compilation of brook trout history, biology, and current status in the state from the perspective of both angler and fisheries manager.  

The history of fisheries management is rooted in the attempt to reverse declines in popular fisheries and maintain fishing quality over time.  While most people can easily relate to this concept, further understanding of the practice of fish management is often lacking.  Bonney attempts to bridge this gap in understanding between biologists and the public by describing in detail the research and data collection practices undergone in the fisheries field and why biologists do certain things.

In the book, Bonney, who has been a fisheries biologist for the Maine Department of Inland Fisheries and Wildlife for 34 years, illustrates perhaps the best case yet for responsible stewardship of Maine’s brook trout resources.  He describes the long history and current status of brook trout fishing in Maine, including historical accounts of trophy squaretails caught in the state, and changes in the fishery over time resulting from the decline of brook trout populations in many waters. 

Forrest Bonney not only thoroughly describes the biology of brook trout in Squaretails; he also documents a fairly complete history of research and management practices that relate to brook trout in the state of Maine.  He explains the current threats to brook trout populations, as well as the future research needs to allow for proper stewardship of this valuable resource well into the future. 

Mark McCollough provides captivating cover art and other illustrations, and Ethan Nadeau and others provide excellent photography and illustrations, adding a valuable artistic element to the book.    

Squaretails is the most complete resource on Maine brook trout currently available and is a must read for Maine anglers and brook trout enthusiasts everywhere.  This book, as well as a more technical version of the same content are published by the Maine Department of Inland Fisheries and Wildlife, and can be purchased at http://www10.informe.org/webshop_ifw/index.php?p=1859&c=12&storeID=2 . 

Results from a recent genetic study in the state of New Jersey appear to indicate that some populations of brook trout in the state still contain the genes of the native strains that existed long before humans occupied the area.  The results come from research conducted by fisheries biologist Pat Hamilton, in conjunction with East Stroudsburg University. 

For many anglers, this is great news.  The idea of catching a native strain of trout holds great value for some.  Others, on the other hand, just want to catch fish, and may be dismayed by the idea that having native strains of trout may cause more restrictive fishing regulations.

The release of these findings come on the heels of a proposal to change the minimum length limit for trout in New Jersey from 7″ to 9″, among other proposed changes.

Read more about the genetic study here

Ongoing research at Washington State University continues to focus on answering questions important to the fish culture and minimizing impacts on native fish populations.  Professor Gary Thorgaard’s Center for Reproductive Biology raises thousands of cloned juvenile rainbow trout.  Scientists at the center study disease resistance, stress response and growth rates, all of which may have important implications for the future of fisheries, particularly in the northwestern United States.

Read more about the research laboratory here

While they can be very popular sportfish in some parts of the world, and have a small following here in the U.S., carp are generally considered a serious nuisance to most anglers and water users in America.  This is particularly true in the Midwest, where carp have taken over a large percentage of lakes and ponds, mucking up the bottom and destroying plant life, making it hard for other fish to survive.  You can read more about carp in one of my previous blog posts, entitled Carp…Those Pesky Critters!

Although carp have destroyed many midwestern lake ecosystems, University of Minnesota researcher Peter Sorensen believes that it doesn’t have to be that way.  With support from a number of different user groups and agencies, Sorensen has begun research on potential methods to eliminate carp in lakes. 

Efforts to remove carp from lakes can be successful, but require huge amounts of time and labor, and sometimes aren’t cost effective.  Sorensen is working on ways to change this, like developing pheromones to lure carp to a central capture location, or create scenarios where other fish eat juvenile carp.  Time will tell whether or not such methods can prove to be effective, but if they are, they will benefit people with carp problems all around the world.

Read more about the potentially groundbreaking research here 

Scientists have discovered a fish that can live for months at a time out of the water!  Recent observations have identified that the mangrove killifish, which lives in swamps in areas like Florida and Belize, spends a good portion of its life living inside trees at the water’s edge.  When pools of water dry up, the fish apparently slithers into cracks and spaces in the logs of mangrove trees.  What a cool way to combat dry climate!

Read more about the mangrove killifish here 

Recent research from Oregon State University has raised a considerable amount of concern about the role of hatchery fish and their use in salmon recovery efforts.

The study has shown that domesticating salmon in the hatchery environment can significantly reduce their reproductive potential, so that individuals do not contribute to future generations nearly as much as wild fish do. 

While the study calls to question the role of hatchery fish in recovery, I think that hatchery salmon still play a significant role in providing a sport fishery, and buffering the impacts of angling on wild salmon.

Concerns about the genetic (and other) consequences of mixing hatchery and wild salmon may become even more considerable as a result of this work.  But I think the real question is whether or not we can even recover wild salmon without the help of hatcheries, especially considering the incredibly high percentage of hatchery fish making up many of our salmon runs on both coasts.

Full story from Science Daily

Just when you thought you’d heard it all…..

Japanese scientists have found a way to successfully cause one species of fish to produce the offspring of a totally separate species, through the injection of the other species’ hormones at the early developmental level.  In other words, scientists can cause salmon to produce trout!!!  Genetic testing has apparently proven this method to be extremely effective, and experts hope to use it to help recover populations of rare and endangered fish species through what they call “surrogate broodstocking”. 

The technique was first tested in Japan, and Idaho researchers plan to look into using it to help recover populations of sockeye salmon.

See the full story here

The Missouri Department of Conservation is funding a 3 year research project investigating the spawning habits and movement patterns of catfish in the Missouri River and its tributaries.  While adequate data exists for other game species, little is known about catfish spawning ecology.  This research could provide fisheries managers with essential information needed to make recommendations about season, length and bag limits, which would likely result in more and bigger catfish for Missouri anglers.  The DOC is considering a number of regulation options to provide a better fishery, but plans to wait on research results before making regulation decisions.

Read more about the catfish research going on, and the options the DOC is pursuing here. 

Some results from a study investigating the performance of rainbow trout in southern Maine are posted below, courtesy of the Maine Department of Inland Fisheries and Wildlife, and Sebago Region Assistant Regional Fisheries Biologist Jim Pellerin.  These results were also posted in another network blog, Daily Bag Limit.

In the fall of 1997, the Fishery Division established a committee comprised of biologists and hatchery staff to revisit the prospect of a rainbow trout stocking program. After deliberation of the pros and cons, the committee concluded to move forward with a limited, experimental program to evaluate the relative performance of rainbow trout, brown trout, and brook trout. While some people contend rainbows would provide angling diversity, our intentions were to determine if rainbows could provide fishery managers with an additional tool to improve fishing opportunities for Maine anglers. The study was conducted over a 5-6 year period in a variety of Maine waters and included three parts: (1) hatchery performance comparisons among all three species, (2) field performance comparisons of browns and rainbows, and (3) field performance comparisons of brookies and rainbows. A federal hatchery in Tennessee provided Eagle Lake Strain rainbow eggs used during the study.

The study is finally winding down, a draft report for part one and two has been completed. The results of the brown trout/rainbow trout field comparison were highlighted in last winter in a similar article. A draft report for the brook trout/rainbow trout comparisons is currently being reviewed, and a final report is expected to be out by this summer. Highlights from the 3rd and final report are presented in the remainder of this article.

This portion of the study evaluated the relative field performance of Eagle Lake strain rainbow trout and Maine Hatchery strain brook trout in four small, trout ponds including: Jaybird Pond (Hiram), Lily Pond (New Gloucester), Long Pond (Denmark), and Overset Pond (Greenwood). Study objectives were: (1) to compare angler catch/harvest rates and examine whether the two trout species differ in their seasonal availability to the angler; (2) to evaluate relative size and growth, (3) to assess survival and carry-over potential; (4) to compare their utilization of the food chain, and (5) to examine trout performance in waters with marginal summer water quality under different levels of competitions/predation.

Catch and Harvest Rates… Across all waters, legal-sized rainbow trout were caught and harvested at rates 2.5 and 3.8 times greater than brook trout, respectively. These results are not at all that surprising, rainbows were slightly larger than the brookies, and a higher proportion of rainbows were of legal-size rainbows at the time of stocking. A comparison of the combined catch of all legal and sublegal fish (all trout/hour) allows for a more standardized comparison, and addresses the size differential issue. Catch rates (all trout/hr) for individual study waters were higher for rainbow trout on three out of the four waters; however, the overall difference across all four waters was relatively small (1.2 times higher). The data suggest that full season catch rates are fairly similar between the two species.

On the other hand, a review of catch rates by early, mid and late season shows that brook trout typically provided slightly better early season angling opportunities, whereas rainbow trout yielded about 2 ½ times higher catch rates during mid and late season period.

Size Quality and Growth… Brook trout produced fisheries of lower size quality than rainbow trout. Brook trout averaged 11.2 inches long and weighed 0.62 pounds, where as rainbows averaged 14.6 inches long and weighed 1.1 pounds across all study waters. This data demonstrates that rainbow trout typically provided better fisheries in terms of size quality. However, the above data does not clarify whether or not the longer lengths and higher weights for rainbow trout are due to better growth, because the mean size differences may simply be a function of the rainbows being stocked at slightly larger sizes and demonstrating better survival.

To answer this question, the increase in growth since stocking (incremental growth) was examined, eliminating the initial size advantage at time of stocking. In addition, incremental growth data was further broken down by month to develop a monthly grow rate. The use of monthly growth rates allows fish that were sampled at different times during the study to be compared. Rainbow trout exhibited better monthly growth rates than brook trout, both in terms of length and weight. Monthly growth for rainbows was approximately 50% greater than for brook trout for both length and weight.

Holdover and Survival….Rainbow trout survival (holdover potential) exceeded brook trout on three out of the four study ponds. The annual survival estimate for rainbow trout was 2.7 times greater that brook trout (14 and 38%). Across all waters, brook trout older than 1+ comprised only 10.0% of our sample compared to 55.1% for rainbow trout. These results indicate rainbow trout are more likely to provide quality and trophy sized trout fishing opportunities than brook trout.

Diets….Fall diets of brook trout and rainbow trout were very similar, and surprisingly Eagle Lake strain rainbow trout did not appear to utilize larger, non-insect type food items (i.e. fish, mollusks, crayfish) anymore than brook trout. On the other hand, rainbow trout exhibited fewer empty stomachs and a higher volume of food/kilogram of trout. This may suggest that rainbow trout are more aggressive feeders, which could account for the higher growth rate observations.

Water Quality and Competition….Although our sample size was limited to only four ponds, collected survival and growth information suggests rainbow trout were more tolerant of competition and/or predation pressures than brook trout. For example, Lily Pond produced good numbers of holdover rainbow trout in the 14-18 inch range, despite heavy competition from largemouth bass, chain pickerel, black crappie, pumpkinseed sunfish, and several other fish species. On the other hand, we observed only a total of three brook trout during the four sampling events conducted between 2001 and 2006. Interestingly, rainbows demonstrated poorer survival to older ages in two ponds with limited water quality (Long and Jaybird Ponds), despite lower level levels of competition than Lily P. This suggests poor to marginal summer water quality conditions may be more limiting to rainbow trout performance than heavy competition.

In conclusion, our initial and most important reason for investigating rainbow trout performance was to explore their potential for improving angling opportunities for coldwater fish, particularly in marginal trout ponds and “put-and-take” stocking programs. Performance results from this study indicate rainbow trout have the potential to produce longer season fishing opportunities, better size quality fisheries, and a limited number of trophy-sized (≥ 18 inches) trout without sacrificing overall catch rates. However, as a trout, they still have their limitations and will only produce longer season “put-and-take” fisheries of slightly larger size quality in waters with extremely marginal water quality. In such cases, a brook trout stocking program may yield the same returns, except over a shorter period of time. On certain marginal waters currently managed for brook trout, the replacement of “put-and-take” brook trout stocking programs with rainbow trout could improve angling opportunities for coldwater sportfish in Maine.

Before the Department adopts a rainbow trout stocking program, all of the associated hatchery and management implications of such a program need to be considered. For example, if a brood stock were developed, additional equipment would be required to manipulate rainbow trout spawning times if a fall spawning strain is preferred. Fishery managers may need to protect spring spawning rainbow trout due to their vulnerability to anglers and poachers. If rainbow trout do not replace existing program, then the largest obstacle to overcome will probably be associated with space constraints in our existing hatchery system.

Perhaps, the most important consideration in initiating a rainbow trout stocking program is their potential to negatively impact native salmonids like brook trout and landlocked salmon. While I agree with Scott and Crossman’s statement in Fishes of Canada, “The rainbow has been one of the more successful, more appreciated, and less potential dangerous of the many attempts to introduce fish to areas beyond its natural range;” it would be irresponsible of the Department to not seriously consider the risks associated with the introduction of a non-native trout species into Maine waters. An important component of this risk assessment is the development of a sound rainbow trout stocking policy to provide assurances that important native fisheries will not be jeopardized by rainbow introductions. In addition, existing Department policies require all new stockings receive Division-wide peer review. This formal process ensures that new stocking proposals are justified. Additionally, existing policies also have an outreach component, which includes a requirement that public input be sought in response to proposed new stockings. Typical venues for this input include this newsletter, weekly fishing reports posted on the Department’s web site and in some local newspapers, sportsmen’s forums, and appearances at fish and game clubs and other groups.

-Jim Pellerin, Sebago Region Assistant Regional Fisheries Biologist, Department of Inland Fisheries and Wildlife

I just returned from a 3 day stream sampling trip in northeast Utah’s Uinta Mountains.  We used backpack electroshockers to collect fish from 10 randomly located reaches in tributary streams to the Bear River. 

We blocked off 100 meter sections of stream with nets and used a three-pass depletion method similar to the one used in our Logan River canoe electrofishing surveys, but at a much smaller scale.

We captured a number of Bonneville cutthroat trout and brook trout, as well as nongame fishes like mountain suckers, leatherside chubs and speckled dace.  We tagged all of the trout with individually numbered external floy tags and internal PIT tags for future ID and growth/survival estimates.  Part of the project is also investigating trout movement, so we used unique tag colors for each site sampled. 

We pulled some beautiful trout out of some of these tiny mountain streams.