Sentinel Lakes Program: MPCA Update – WQ Sampling, Data Analysis & Reporting Steve Heiskary Prepared in conjunction with: Jesse Anderson Pam Anderson Lee Engel Matt Lindon Kelly O’Hara Lakes and Streams Monitoring Unit Water Monitoring Section Environmental Analysis and Outcomes Division

Outline  2008 sampling & data analysis overview;  Sentinel Lake Summary sheets – approach & schedule  Reporting Plan for ;  Collaboration with MDNR staff on LAP reporting;  Sampling 2009  Summary

WQ & related monitoring  Profiles – DO, temperature, conductivity & 1m intervals;  Standard water chemistry: nutrients, chlorophyll- a, TSS, color, alkalinity,  Special – cation, anion, TOC  Algal sample  Near-shore assessment (NLAP protocol) – 10 random sites at least once on each;  Monthly observations for exotics (curly-leaf) at many lakes;

2008 MPCA WQ sampling  ~monthly May- September (full suite: May, July & October) nutrients and chl-a remainder;  CLMP Secchi - ~18 lakes  Volunteer DO & temperature profiles ~18 lakes  Linked with existing TMDL or other monitoring where possible ( e.g. Peltier);

Summary of # of near-shore assessments (1 complete NLAP assessment) & exotics recon. conducted by staff # of lakes with volunteer assistance May be willing to continue but may be limited by # of DO meters available in 2009 and future years;

Using MPCA & volunteer profile data: St. Olaf Lake Temperature & DO Isopleths based on MPCA & volunteer measurements (created by Matt Lindon)

Sentinel Lake Summary sheets  Purpose – provide brief summary data & analysis for each lake (4 pages);  Focus on basic lake & watershed characteristics, summer-mean WQ, available trend data;  Summarize watershed, WQ, fisheries & plant management issues;  Audience – anyone interested in Sentinel Lakes program: volunteers, other researchers, legislators, etc.

Example of fish & plant survey summary: Madison Lake, Blue Earth County Note – MPCA near-shore assessments at 10 random sites in May & June found heavy infestation of curly-leaf (implies value of routine- random site observations)

Summer-mean 2008 as compared to typical range based on ecoregion reference lakes. Include additional year when available

Compare 2008 profile with that from an earlier survey Kelly & Jesse).

Compare profile series among years: Madison Lake: Variable stratification patterns among years

Stratification & stability of thermocline has a direct impact on DO & may impact WQ as well 2006 – anoxic hypolimnion from 6m to bottom July – late August

Well-mixed lake with curly-leaf: Portage Lake. Common pattern in shallow lakes Stratified lake – Cedar Lake, Morrison County

Figure 4. Portage Lake Summer-mean Secchi, TP & Chl-a 303(d) listed in 2006 TMDL start date – 2014 Sentinel report can provide information to be used in TMDL assessment & reporting

Lake Shaokatan, Lincoln County: Use of sediment cores & diatom reconstruction of TP

Sentinel Lakes: MPCA data & reporting summary Need to roll-out over several years to allow completion for all lakes; Begin with those with strongest databases; In 2008: Jesse – 2 Kelly – 1 Lee – 2 Matt – 1 Pam - 1

Summary   MPCA staff sampled all lakes in 2008 – in general on a monthly basis;   Citizen volunteer and park staff monitor included on many lakes – important to continue at least Secchi into the future;   MPCA staff have draft Sentinel Summary sheets for all lakes (edits welcome); will finalize, PDF and place on MPCA web site following this meeting (edits welcome, please forward within next week or so);   MPCA (Lakes & Streams Unit) proposes to continue to sample each lakes that is not fully assessed for 303(d) “TMDL” purposes in 2009;   Will need assistance from summer interns to continue our monitoring effort (this and lab budget can be a focus of future discussion);   We will write LAP-type reports that will provide a baseline for each of the lakes – (begin in 2008, complete by 2011);   These reports will provide a good baseline status and trend report for each lake; sound basis for deciding the frequency & intensity of future monitoring, and should serve to help shape future proposals for the Sentinel Lakes program.