WDNR Yahara Lakes Fisheries: Fish Lengths and Weights 1987-1998
These data were collected by the Wisconsin Department of Natural Resources (WDNR) from 1987-1998. Most of these data (1987-1993) precede 1995, the year that the University of Wisconsin NTL-LTER program took over sampling of the Yahara Lakes. However, WDNR data collected from 1997-1998 (unrelated to LTER sampling) is also included. In 1987 a joint project by the WDNR and the University of Wisconsin-Madison, Center for Limnology (CFL) was initiated on Lake Mendota. The project involved biomanipulation of fish communities within the lake, which was acheived by stocking game fish species (northern pike and walleye). The goal was to induce a trophic cascade that would improve the water clarity of Lake Mendota. See Lathrop et al. 2002. Stocking piscivores to improve fishing and water clarity: a synthesis of the Lake Mendota biomanipulation project. Freshwater Biology 47, 2410-2424. In collecting these data, the objective was to gather population data and monitor populations to track the progress of the biomanipulation. The data is dominated by an assesssment of the game fishery in Lake Mendota, however other Yahara Lakes and non-game fish species are also represented. A combination of gear types was used to gather the population data including boom shocking, fyke netting, mini-fyke netting, seining, and gill netting. Not every sampling year includes length and weight data from all gear types. The WDNR also carried out randomized, access-point creel surveys to estimate fishing pressure, catch rates, harvest, and exploitation rates. Five data files each include length-weight data, and are organized by the type of gear or method which was used to collect the data: 1) fyke, mini-fyke, and seine netting 2) boom shocking 3) gill netting (1993 only) 4)walleye age as determined by scale and spine analysis (1987 only), and 5) creel survey. The final data file contains creel survey information: number of anglers fishing the shoreline, and number of anglers that started and completed trips from public and private access points.
The WDNR completed random access point creel surveys from 1989-1996. During the open water season (March-December) they surveyed at boat launches and popular fishing sites. At each of these sites an instantaneous count of shore anglers was made upon arrival at the site. In addition, they also made continuous counts of anglers starting and completing trips at public and private access points. During the ice fishing season (January-February) a clerk counted the number of anglers starting and completing trips during the scheduled stop at each access point.
This material is based upon work supported by the National Science Foundation under Cooperative Agreement #DEB-1440297, NTL LTER. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.