Mason Bryant - Academia.edu (original) (raw)

Papers by Mason Bryant

North American Journal of Fisheries Management, Jul 1, 1983

Debris removal is a frequently used management technique for small streams in logged watersheds, ... more Debris removal is a frequently used management technique for small streams in logged watersheds, but many stream-cleaning techniques overlook important habitat requirements of juvenile salmonids. Reviews of some past management practices show little systematic evaluation or monitoring of physical or biological effects. A review of several studies (most of them not associated with debris removal) shows the importance of woody debris as salmonid habitat. The role of organic debris in small stream systems is discussed and a set of criteria for debris removal is proposed.

Transactions of The American Fisheries Society, May 1, 2002

The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast ... more The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast Alaska watersheds is poorly understood. We observed movements of steelhead Oncorhynchus mykiss, coho salmon O. kisutch, and Dolly Varden Salvelinus malma between mainstem and tributary habitats at weirs located on tributaries in the Staney Creek watershed in southeast Alaska. We used seasonal relative abundance (catch per unit effort) in eight main-stem reaches and eight tributaries to corroborate observed movement in the two streams with weirs. We observed juvenile steelhead and coho salmon moving through the weirs into tributaries during the fall as flows increased and temperatures decreased. The relative abundance of steelhead was greater in main-stem sites than in tributaries during the summer, whereas during spring and fall relative abundance in the tributaries was similar to that in the main stem. Juvenile coho salmon were abundant in tributaries during all seasons. The relative abundance of Dolly Varden was greater in the tributaries than in the main-stem during all seasons. These results underscore the significance of links between main-stem habitats and small tributaries for production of juvenile salmonids.

Ecology of Freshwater Fish, Sep 1, 2007

The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead Pi... more The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead Piccolo JJ, Hughes NF, Bryant MD. The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead.

The Progressive fish culturist, Jul 1, 1987

... MASON D. BRYANT 1 US Forest Service, Pacific Northwest Forest and Range Experiment Station Fo... more ... MASON D. BRYANT 1 US Forest Service, Pacific Northwest Forest and Range Experiment Station Forestry Sciences Laboratory, Post Office Box ... A set of equations describes the relationship between temperature and centigrade units to 50% hatch and to 100% yolk absorption ...

Climatic Change, Jan 14, 2009

General circulation models predict increases in air temperatures from 1 • C to 5 • C as atmospher... more General circulation models predict increases in air temperatures from 1 • C to 5 • C as atmospheric CO 2 continues to rise during the next 100 years. Thermal regimes in freshwater ecosystems will change as air temperatures increase regionally. As air temperatures increase, the distribution and intensity of precipitation will change which will in turn alter freshwater hydrology. Low elevation floodplains and wetlands will flood as continental ice sheets melt, increasing sea-levels. Although anadromous salmonids exist over a wide range of climatic conditions along the Pacific coast, individual stocks have adapted life history strategies-time of emergence, run timing, and residence time in freshwater-that are often unique to regions and watersheds. The response of anadromous salmonids will differ among species depending on their life cycle in freshwater. For pink and chum salmon that migrate to the ocean shortly after they emerge from the gravel, higher temperatures during spawning and incubation may result in earlier entry into the ocean when food resources are low. Shifts in thermal regimes in lakes will change trophic conditions that will affect juvenile sockeye salmon growth and survival. Decreased summer stream flows and higher water temperatures will affect growth and survival of juvenile coho salmon. Rising sea-levels will inundate low elevation spawning areas for pink salmon and floodplain rearing habitats for juvenile coho salmon. Rapid changes in climatic conditions may not extirpate anadromous salmonids in the region, but they will impose greater stress on many stocks that are adapted to present climatic conditions. Survival of sustainable populations will depend on the existing genetic diversity within and among stocks, conservative harvest management, and habitat conservation.

North American Journal of Fisheries Management, May 1, 2000

The opening of a fish ladder in 1990 enabled migration of anadromous fishes into Margaret Lake, A... more The opening of a fish ladder in 1990 enabled migration of anadromous fishes into Margaret Lake, Alaska, dramatically changing the environment for its resident cutthroat trout Oncorhynchus clarki. Cutthroat trout summer growth was inferred from scales collected in the fall from 1989 to 1997 by measuring the distance between the scale edge and the last annuli. Bias in scale aging

Transactions of The American Fisheries Society, 2010

Lohr, Samuel C.; Bryant, Mason D. 1999. Biological characteristics and population status of steel... more Lohr, Samuel C.; Bryant, Mason D. 1999. Biological characteristics and population status of steelhead (Oncorhynchus mykiss) in southeast Alaska. Gen. Tech. Rep.

North American Journal of Fisheries Management, Nov 1, 2000

Passive capture methods, such as minnow traps, are commonly used to capture fish for mark-recaptu... more Passive capture methods, such as minnow traps, are commonly used to capture fish for mark-recapture population estimates; however, they have not been used for removal methods. Minnow traps set for 90-min periods during three or four sequential capture occasions during the summer of 1996 were used to capture coho salmon Oncorhynchus kisutch fry and parr, Dolly Varden Salvelinus malma, cutthroat trout O. clarki, and juvenile steelhead O. mykiss to estimate population size with the Zippin or generalized removal method. More than 45% of the total catch was obtained during the first capture occasion, and in most cases, the catch during the fourth occasion was less than 15% of the total catch. In most pools, the probability of capture was greater than 0.4 but was lower for coho salmon fry than for coho salmon parr and other species. Mean population estimates for coho salmon parr made with concurrent mark-recapture and removal methods differed significantly in small streams. Estimates from mark-recapture and removal methods were not significantly different for coho salmon fry and Dolly Varden, but mark-recapture estimates were higher than removal estimates in most cases. My results show that removal estimates can be obtained with minnow traps if sampling procedures conform to the assumptions required for the method.

Canadian Journal of Fisheries and Aquatic Sciences, Feb 1, 2008

North American Journal of Fisheries Management, Nov 1, 2004

Stream habitat surveys and watershed assessments have been developed and used as monitoring tools... more Stream habitat surveys and watershed assessments have been developed and used as monitoring tools for decades. Most rely on type I error as the primary criterion, with minor consideration of statistical power and effect size. We test for statistical differences in fish habitat condition between harvested and nonharvested watersheds from habitat survey data collected in southeast Alaska. We apply statistical power analysis to judge whether nonsignificant results can be interpreted with confidence. None of the fish habitat variables we examined were significant at ␣ ϭ 0.05; however, several P-values were less than 0.10 and consistent differences between harvested and nonharvested reaches were observed among channel types. Statistical power is low and the probability of not detecting differences is high when the effect size, scaled to the standard deviation of the measurement, is small to medium. For large effect sizes, the ability to detect differences was greater but did not exceed 85% for any measurement. Statistical power, effect size, and biological significance of the outcome are important considerations when the results are interpreted and can lend additional information to managers making decisions with data that are less than perfect.

Environmental Biology of Fishes, Jan 26, 2008

Fisheries, Nov 1, 1995

Abstract Long-term habitat degradation has increased public recognition of the need for watershed... more Abstract Long-term habitat degradation has increased public recognition of the need for watershed and stream habitat restoration. With such recognition is the demand for accountability, but the effects of restoration and recovery of watersheds are complex and long-term. A monitoring program that provides sufficient information to evaluate the effectiveness of these efforts will be expensive. A pulsed monitoring strategy that consists of a series of short-term (3–5 years), high-intensity studies separated by longer periods (10–15 years) of low-density data collection can provide an effective means of implementing a long-term monitoring program with a reasonable degree of success and cost.

North American Journal of Fisheries Management, Jul 1, 1983

Debris removal is a frequently used management technique for small streams in logged watersheds, ... more Debris removal is a frequently used management technique for small streams in logged watersheds, but many stream-cleaning techniques overlook important habitat requirements of juvenile salmonids. Reviews of some past management practices show little systematic evaluation or monitoring of physical or biological effects. A review of several studies (most of them not associated with debris removal) shows the importance of woody debris as salmonid habitat. The role of organic debris in small stream systems is discussed and a set of criteria for debris removal is proposed.

Transactions of The American Fisheries Society, May 1, 2002

The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast ... more The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast Alaska watersheds is poorly understood. We observed movements of steelhead Oncorhynchus mykiss, coho salmon O. kisutch, and Dolly Varden Salvelinus malma between mainstem and tributary habitats at weirs located on tributaries in the Staney Creek watershed in southeast Alaska. We used seasonal relative abundance (catch per unit effort) in eight main-stem reaches and eight tributaries to corroborate observed movement in the two streams with weirs. We observed juvenile steelhead and coho salmon moving through the weirs into tributaries during the fall as flows increased and temperatures decreased. The relative abundance of steelhead was greater in main-stem sites than in tributaries during the summer, whereas during spring and fall relative abundance in the tributaries was similar to that in the main stem. Juvenile coho salmon were abundant in tributaries during all seasons. The relative abundance of Dolly Varden was greater in the tributaries than in the main-stem during all seasons. These results underscore the significance of links between main-stem habitats and small tributaries for production of juvenile salmonids.

Ecology of Freshwater Fish, Sep 1, 2007

The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead Pi... more The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead Piccolo JJ, Hughes NF, Bryant MD. The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead.

The Progressive fish culturist, Jul 1, 1987

... MASON D. BRYANT 1 US Forest Service, Pacific Northwest Forest and Range Experiment Station Fo... more ... MASON D. BRYANT 1 US Forest Service, Pacific Northwest Forest and Range Experiment Station Forestry Sciences Laboratory, Post Office Box ... A set of equations describes the relationship between temperature and centigrade units to 50% hatch and to 100% yolk absorption ...

Climatic Change, Jan 14, 2009

General circulation models predict increases in air temperatures from 1 • C to 5 • C as atmospher... more General circulation models predict increases in air temperatures from 1 • C to 5 • C as atmospheric CO 2 continues to rise during the next 100 years. Thermal regimes in freshwater ecosystems will change as air temperatures increase regionally. As air temperatures increase, the distribution and intensity of precipitation will change which will in turn alter freshwater hydrology. Low elevation floodplains and wetlands will flood as continental ice sheets melt, increasing sea-levels. Although anadromous salmonids exist over a wide range of climatic conditions along the Pacific coast, individual stocks have adapted life history strategies-time of emergence, run timing, and residence time in freshwater-that are often unique to regions and watersheds. The response of anadromous salmonids will differ among species depending on their life cycle in freshwater. For pink and chum salmon that migrate to the ocean shortly after they emerge from the gravel, higher temperatures during spawning and incubation may result in earlier entry into the ocean when food resources are low. Shifts in thermal regimes in lakes will change trophic conditions that will affect juvenile sockeye salmon growth and survival. Decreased summer stream flows and higher water temperatures will affect growth and survival of juvenile coho salmon. Rising sea-levels will inundate low elevation spawning areas for pink salmon and floodplain rearing habitats for juvenile coho salmon. Rapid changes in climatic conditions may not extirpate anadromous salmonids in the region, but they will impose greater stress on many stocks that are adapted to present climatic conditions. Survival of sustainable populations will depend on the existing genetic diversity within and among stocks, conservative harvest management, and habitat conservation.

North American Journal of Fisheries Management, May 1, 2000

The opening of a fish ladder in 1990 enabled migration of anadromous fishes into Margaret Lake, A... more The opening of a fish ladder in 1990 enabled migration of anadromous fishes into Margaret Lake, Alaska, dramatically changing the environment for its resident cutthroat trout Oncorhynchus clarki. Cutthroat trout summer growth was inferred from scales collected in the fall from 1989 to 1997 by measuring the distance between the scale edge and the last annuli. Bias in scale aging

Transactions of The American Fisheries Society, 2010

Lohr, Samuel C.; Bryant, Mason D. 1999. Biological characteristics and population status of steel... more Lohr, Samuel C.; Bryant, Mason D. 1999. Biological characteristics and population status of steelhead (Oncorhynchus mykiss) in southeast Alaska. Gen. Tech. Rep.

North American Journal of Fisheries Management, Nov 1, 2000

Passive capture methods, such as minnow traps, are commonly used to capture fish for mark-recaptu... more Passive capture methods, such as minnow traps, are commonly used to capture fish for mark-recapture population estimates; however, they have not been used for removal methods. Minnow traps set for 90-min periods during three or four sequential capture occasions during the summer of 1996 were used to capture coho salmon Oncorhynchus kisutch fry and parr, Dolly Varden Salvelinus malma, cutthroat trout O. clarki, and juvenile steelhead O. mykiss to estimate population size with the Zippin or generalized removal method. More than 45% of the total catch was obtained during the first capture occasion, and in most cases, the catch during the fourth occasion was less than 15% of the total catch. In most pools, the probability of capture was greater than 0.4 but was lower for coho salmon fry than for coho salmon parr and other species. Mean population estimates for coho salmon parr made with concurrent mark-recapture and removal methods differed significantly in small streams. Estimates from mark-recapture and removal methods were not significantly different for coho salmon fry and Dolly Varden, but mark-recapture estimates were higher than removal estimates in most cases. My results show that removal estimates can be obtained with minnow traps if sampling procedures conform to the assumptions required for the method.

Canadian Journal of Fisheries and Aquatic Sciences, Feb 1, 2008

North American Journal of Fisheries Management, Nov 1, 2004

Stream habitat surveys and watershed assessments have been developed and used as monitoring tools... more Stream habitat surveys and watershed assessments have been developed and used as monitoring tools for decades. Most rely on type I error as the primary criterion, with minor consideration of statistical power and effect size. We test for statistical differences in fish habitat condition between harvested and nonharvested watersheds from habitat survey data collected in southeast Alaska. We apply statistical power analysis to judge whether nonsignificant results can be interpreted with confidence. None of the fish habitat variables we examined were significant at ␣ ϭ 0.05; however, several P-values were less than 0.10 and consistent differences between harvested and nonharvested reaches were observed among channel types. Statistical power is low and the probability of not detecting differences is high when the effect size, scaled to the standard deviation of the measurement, is small to medium. For large effect sizes, the ability to detect differences was greater but did not exceed 85% for any measurement. Statistical power, effect size, and biological significance of the outcome are important considerations when the results are interpreted and can lend additional information to managers making decisions with data that are less than perfect.

Environmental Biology of Fishes, Jan 26, 2008

Fisheries, Nov 1, 1995

Abstract Long-term habitat degradation has increased public recognition of the need for watershed... more Abstract Long-term habitat degradation has increased public recognition of the need for watershed and stream habitat restoration. With such recognition is the demand for accountability, but the effects of restoration and recovery of watersheds are complex and long-term. A monitoring program that provides sufficient information to evaluate the effectiveness of these efforts will be expensive. A pulsed monitoring strategy that consists of a series of short-term (3–5 years), high-intensity studies separated by longer periods (10–15 years) of low-density data collection can provide an effective means of implementing a long-term monitoring program with a reasonable degree of success and cost.