US Long-Term Ecological Research Network

Sampling Schedule

Summer fieldwork was divided into two rounds of sampling. All 28 focus lakes were first sampled for water chemistry and coarse woody habitat (CWH). These sampling procedures were performed on the same day for each lake. This sampling ran from 1 June - 25 June. The second half of the summer was devoted to sampling macrophyte communities using point intercept (PI) surveys. PI surveys were conducted on the study lakes from 10 July - 11 August.

Lake Order

For chemistry and CWH sampling, lake order was determined using a stratified random sampling technique.  Focus lakes were divided into four categories (low conductivity, low development; low conductivity, high development; high conductivity, low development; high conductivity, high development). A lake was randomly selected from each category in turn until all 28 lakes had been placed in order.  Lake order for PI surveys was randomly selected.

Crew Logistics

In 2015 four full-time and two part-time technicians worked on the Regional Lake Survey.  During each day of sampling, workers divided into crews of 2-3 people so that two lakes could be sampled each day. Crews of three were most efficient, especially for the PI surveys. Crews were randomly shuffled each day to reduce bias.


Several days were devoted to training before each round of sampling. During the last week of May, training exercises were conducted on Sparkling lake. These exercises allowed the crew to practice chemistry and CWH sampling as well as basic trailering and boating techniques. This training was led by supervisors Noah Lottig and Tim Kratz and a crew member with previous experience with LTER's water chemistry sampling protocols.

To prepare for macrophyte sampling, all crew members attended an aquatic plant identification workshop led by Susan Knight. Additionally, during the first week of PI surveys, crews went to field with one of two plant experts, Susan Knight and Carol Warden. This field training was critically important in strengthening the crew's ability to identify macrophytes.

Cleaning Procedure

Throughout the summer members of the Regional Lakes Survey followed the WDNR's most current guidelines for watercraft and gear decontamination. Boats, oars, PI rakes, and anchors were cleaned using a pressure steam washer. Waders, ropes, floats, calipers and meter tapes were cleaned with bleach solution. Graduated cylinders and Wisconsin nets were washed with tap water while chemistry tubing was cleaned using deionized water.  Cleaning procedures were modified slightly for Stormy Lake, which contains spiny water fleas. A boat and Wisconsin net were borrowed from DNR scientist Carol Warden and extra care was taken in cleaning all gear after sampling.

Protocol Format
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