This project will improve aquatic habitat and water quality in the Sunrise River chain of Lakes in Anoka County including Typo, Martin and Linwood Lakes. The project was preceded by installation of carp barriers within the chain of lakes to limit seasonal migrations and recolonization. By working throughout this chain of lakes we will create a connected network of habitat yielding multiple benefits to fish, wildlife and water.
Carp strongly degrade aquatic habitat and water quality through their feeding behaviors, and they currently are dominating fish biomass in this chain of lakes. By digging in the bottom while foraging, carp uproot plants, disturb sediments and release nutrient rich excrement into the water. The result is a lack of vegetative habitat, high turbidity and poor habitat for fish and waterfowl (Haas et al. 2007, Bajer et al. 2009). Carp control will improve water clarity, increase plants, improve game fish community, and enhance desirable wildlife populations.
This is the third phase of carp control at these lakes. During phase one, in 2016 we completed installation of four strategic carp barriers, which were partially funded by a MN DNR Conservation Partners Legacy grant. The barriers separate spawning and overwintering areas to reduce carp reproduction. The barriers also prevent adult re-colonization after carp harvests, correcting a problem that had made benefits of previous harvests short-lived.
Phase two was carp removals in 2017-2019. A MN DNR Conservation Partners Legacy grant and other funding sources achieved removal of 6,873 carp from Typo Lake and 5,232 from Martin Lake. All carp were removed by box netting.
Phase two also included detailed analysis of the carp populations and development of a long-term management strategy at Typo, Martin and Linwood Lakes. This work was led by Dr. Przemek Bajer of Carp Solutions, LLC. Work included radio tracking, population analysis to set goals and track progress, age structure analysis of captured carp, and identification of nursery areas. Radio tags, which have a six-year life, have subsequently been used to guide management.
During the current phase three, we are working to remove approximately 11,000 additional carp. When achieved, the targeted lakes will be at or below the carp management goals. The goal is <89lbs/acre. Above this density carp significantly affect water quality and habitat.
Multiple aquatic habitats will benefit from this project. They include Martin, Typo, Island and Linwood Lakes, >1 mile streams between the lakes, >150 acres of adjacent wetland and downstream waters of the Sunrise and St. Croix Rivers. This project is a priority in local and regional natural resource plans.
Box netting - Box netting of carp has occurred at Typo Lake in 2017-2019 and Martin Lake in 2018-2019. These nets are baited with cracked corn "train" carp to come to the traps. Traps are sprung before daylight, when carp are feeding most. Box netting is continuing in 2020-2021.
Commercial seining – This technique was used only in spring 2020 at Linwood Lake. Additional attempts in the future are anticipated.
Electrofishing - Electrofishing surveys were conducted in 2017 to estimate carp populations at Martin, Typo and Linwood Lakes. This helps us know how many carp need to be removed to reach management goals. During electrofishing many carp are fin-clipped. Recaptures of fin clipped fish helps refine population estimates.
Radio tagging - 20 carp at each Martin, Typo and Linwood Lakes were implanted with radio transmitters and released. These “judas” fish will betray the habits and locations of entire schools for us in the future. Fish locations are tracked periodically. In the event that someone from the public catches one, we’d ask they return it to the water.
Trap netting juveniles - At Martin, Typo, Island and Linwood Lakes, and other waterbodies interconnected to them, trap netting for juvenile carp occurred in 2017 and 20108. This helps us understand how often carp are reproducing, and is also a snapshot of the rest of the fishery. No young carp were captured, a good indication that these carp have not been reproducing recently. That is far better from a management standpoint than a population that is churning out new young every year.
Aging analysis - Heads from >100 harvested carp at each Martin, Typo and Linwood Lakes were kept in 2017 or 2018. These fish were aged by examining growth rings on an internal balance organ in their head. The resulting age structure of the population helps us understand how often carp are successfully reproducing. We found few young fish, indicating that carp are not reproducing in most years. Most carp were between 20 and 30 years old. Linwood Lake has more young (<12 yrs old) carp than the other lakes. This indicates that carp removal can have lasting positive effects on these lakes.
Water quality monitoring – Water quality in these lakes was monitored before and during this project. Monitoring included phosphorus, chlorophyll-a (algae) and Secchi transparency. Lake water quality is improving and both lakes now have statistically significant trends of water quality improvement.
This work has been funded by grants from the State of Minnesota through the Clean Water, Land and Legacy Amendment along with many other local partners. Major funding for the current work is funded by a MN Board of Water and Soil Resources Clean Water Fund grant to the Anoka Conservation District.
This project has been funded through a MN DNR Conservation Partners Legacy grant from the Clean Water, Land and Legacy Amendment and a MN Board of Water and Soil Resources Clean Water Fund grant. Substantial funding also came from the Sunrise River Watershed Management Organization, Martin Lakers Association, Anoka County Aquatic Invasive Species Prevention grant and Anoka Conservation District.
Volunteers were a substantial part of this project’s success. Landowners at each lake hosted box nets that they baited daily. These landowners, other residents and elected officials further donated their time to assist with the carp harvests. In total, hundreds of volunteer hours have been donated!
August 25, 2017 box netting at Typo Lake slide show
September 1, 2017 radio tag implantation at Typo lake slide show