Standard Methods for Sampling North American Freshwater Fishes, second edition

Chapter 3: Warmwater Fish in Large Standing Waters

L. E. (Steve) Miranda, Kimberly I. Bonvechio, Jeff Koch, and Rodrigo Moncayo-Estrada

doi: https://doi.org/10.47886/9781934874769.ch3

With three new coauthors and other important additions, we build upon the foundation of this chapter’s first edition. Recommendations are now provided for a wider geographic range to include large temperate to tropical warm waters throughout North America, from Mexico to Canada. For boat electrofishing, aiming to simplify power metering, we now redefine power targets based on amperage goals. Low-frequency electrofishing has been added as a standard procedure for monitoring select catfish species. Lastly, we provide clarification about the throat design of fyke nets.

Water temperature is a major determinant of fish assemblages in large (>200 ha) standing waters in North America (Matthews 1998). Warm waters are defined as those with average daily summer temperatures >20°C (Winger 1981). From a thermal perspective, fish assemblages are broadly classified as coldwater (e.g., trouts, salmons), coolwater (e.g., percids, pikes), and warmwater (e.g., sunfishes, catfishes). These broad thermal fish assemblage guilds follow latitudinal and altitudinal gradients and associated shifts from coldwater to warmwater assemblages. Shifts are gradual, and many standing waters host assemblages with a mixture of coldwater, coolwater, and warmwater guilds. Warmwater lakes in North America occur mostly in temperate latitudes of southern Canada, temperate and subtropical latitudes of the United States, and subtropical and tropical latitudes of Mexico. These lakes are represented principally by artificial reservoirs, fluvial lakes, tecto-volcanic lakes, and lakes made by surface dissolution of bedrock (e.g., sinkholes) and include largely warmwater and coolwater fish assemblages that have optimal temperatures >15-20°C (Magnuson et al. 1979).