Matthew S. Recsetar

Bio: Matthew S. Recsetar is an academic researcher from University of Arizona. The author has contributed to research in topics: Trout & Catfish. The author has an hindex of 6, co-authored 8 publications receiving 116 citations.

Relationship between fish size and upper thermal tolerance

Abstract: Using critical thermal maximum (CTMax) tests, we examined the relationship between upper temperature tolerances and fish size (fry–adult or subadult lengths) of rainbow trout Oncorhynchus mykiss (41–200-mm TL), Apache trout O. gilae apache (40–220-mm TL), largemouth bass Micropterus salmoides (72–266-mm TL), Nile tilapia Oreochromis niloticus (35–206-mm TL), channel catfish Ictalurus punctatus (62–264 mm-TL), and Rio Grande cutthroat trout O. clarkii virginalis (36–181-mm TL). Rainbow trout and Apache trout were acclimated at 18°C, Rio Grande cutthroat trout were acclimated at 14°C, and Nile tilapia, largemouth bass, and channel catfish were acclimated at 25°C, all for 14 d. Critical thermal maximum temperatures were estimated and data were analyzed using simple linear regression. There was no significant relationship (P > 0.05) between thermal tolerance and length for Nile tilapia (P = 0.33), channel catfish (P = 0.55), rainbow trout (P = 0.76), or largemouth bass (P = 0.93) for the length range...

Upper Thermal Tolerances of Rio Grande Cutthroat Trout under Constant and Fluctuating Temperatures

Abstract: The Rio Grande Cutthroat Trout Oncorhynchus clarkii virginalis is the southernmost subspecies of Cutthroat Trout, and as with the other subspecies, stream temperature regulates growth, reproductive success, distribution, and survival. An understanding of the upper thermal tolerance of Rio Grande Cutthroat Trout is important for developing water temperature standards and for assessing suitable habitat for reintroduction and management. Hatch success of Rio Grande Cutthroat Trout eggs was determined under static temperatures. The thermal requirements of fry and juveniles were also assessed under static and fluctuating temperature regimes using the acclimated chronic exposure method. Egg hatch success was 46–70% from 6°C to 16°C but declined significantly at 18°C and 20°C. Maximum growth of fry that were fed to satiation occurred at 15.3°C. The 30-d ultimate upper incipient lethal temperature (UUILT) was 22.6°C for fry and 21.7°C for juveniles. Survival during fluctuating temperature experiments was...

Survival of Apache Trout Eggs and Alevins under Static and Fluctuating Temperature Regimes

Abstract: Increased stream temperatures due to global climate change, livestock grazing, removal of riparian cover, reduction of stream flow, and urbanization will have important implications for fishes worldwide. Information exists that describes the effects of elevated water temperatures on fish eggs, but less information is available on the effects of fluctuating water temperatures on egg survival, especially those of threatened and endangered species. We tested the posthatch survival of eyed eggs and alevins of Apache Trout Oncorhynchus gilae apache, a threatened salmonid, in static temperatures of 15, 18, 21, 24, and 27°C, and also in treatments with diel fluctuations of ±3°C around those temperatures. The LT50 for posthatch survival of Apache Trout eyed eggs and alevins was 17.1°C for static temperatures treatments and 17.9°C for the midpoints of ±3°C fluctuating temperature treatments. There was no significant difference in survival between static temperatures and fluctuating temperatures that share...

Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change [includes Supporting Information]

Abstract: Broad-scale studies of climate change effects on freshwater species have focused mainly on temperature, ignoring critical drivers such as flow regime and biotic interactions. We use downscaled outputs from general circulation models coupled with a hydrologic model to forecast the effects of altered flows and increased temperatures on four interacting species of trout across the interior western United States (1.01 million km2), based on empirical statistical models built from fish surveys at 9,890 sites. Projections under the 2080s A1B emissions scenario forecast a mean 47% decline in total suitable habitat for all trout, a group of fishes of major socioeconomic and ecological significance. We project that native cutthroat trout Oncorhynchus clarkii, already excluded from much of its potential range by nonnative species, will lose a further 58% of habitat due to an increase in temperatures beyond the species' physiological optima and continued negative biotic interactions. Habitat for nonnative brook trout Salvelinus fontinalis and brown trout Salmo trutta is predicted to decline by 77% and 48%, respectively, driven by increases in temperature and winter flood frequency caused by warmer, rainier winters. Habitat for rainbow trout, Oncorhynchus mykiss, is projected to decline the least (35%) because negative temperature effects are partly offset by flow regime shifts that benefit the species. These results illustrate how drivers other than temperature influence species response to climate change. Despite some uncertainty, large declines in trout habitat are likely, but our findings point to opportunities for strategic targeting of mitigation efforts to appropriate stressors and locations.

Climate Change Effects on North American Inland Fish Populations and Assemblages

Abstract: Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate.

Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges

Abstract: Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives Improved environmental and economic sustainability based on increased efficiency of production continues to be realized As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs

Selection for upper thermal tolerance in rainbow trout (Oncorhynchus mykiss Walbaum)

Abstract: Rainbow trout ( Oncorhynchus mykiss Walbaum) in southern Western Australia have undergone passive selection for over 19 generations to survive high water temperatures. Based on the conceptual model of ‘oxygen- and capacity-limited thermal tolerance’, we measured critical thermal maximum (CT max ), maximum heart rate ( f H,max ) and aerobic scope to test the hypothesis that these rainbow trout can maintain aerobic scope at high temperatures through a robust cardiac performance supporting oxygen delivery. Across five family groups CT max averaged 29.0±0.02°C. Aerobic scope was maximized at 15.8±0.3°C ( T opt ), while the upper pejus temperature ( T pej , set at 90% of maximum aerobic scope) was 19.9±0.3°C. Although aerobic scope decreased at temperatures above T opt , the value at 25°C remained well over 40% of the maximum. Furthermore, pharmacologically stimulated f H,max increased with temperature, reaching a peak value between 23.5±0.4 and 24.0±0.4°C ( T max ) for three family groups. The Arrhenius breakpoint temperature ( T AB ) for f H,max was 20.3±0.3 to 20.7±0.4°C, while the average Q 10 breakpoint temperature ( T QB , when the incremental Q 10 f H,max was 21.6±0.2 to 22.0±0.4°C. Collectively, f H,max progressively became less temperature dependent beyond 20°C ( T AB and T QB ), which coincides with the upper T pej for aerobic scope. Although upper thermal performance indices for both aerobic scope and f H,max were compared among family groups in this population, appreciable differences were not evident. Compared with other populations of rainbow trout, the present assessment is consistent with the prediction that this strain has undergone selection and shows the ability to tolerate higher water temperatures.

Climate Change Impacts on Freshwater Fishes: A Canadian Perspective

Abstract: Current and projected patterns of global climate change are a major concern to freshwater fisheries in Canada. The magnitude of the impacts of climate change vary among species and ecoregions. The ...