Wednesday, December 12, 2012

Recent publication on curly-leaf pondweed

Just a quick post to announce the recent publication of a paper authored by Contour Innovations Chief Aquatic Biologist Ray Valley documenting recent short-term declines of the invasive curly-leaf pondweed potentially due to heavy winter snowfall.  You can access the article here or email Ray at rayv@contourinnovations.com and ask for a pdf copy.

Abstract

Curlyleaf pondweed (Potamogeton crispus) is a long-established, nonnative aquatic plant common throughout southern and central Minnesota that is thought to be expanding northward. Curlyleaf pondweed typically grows abundantly in spring in productive lakes and then senesces in midsummer, often followed by algae blooms. We report observations of widespread, short-term declines in curlyleaf pondweed cover that appear linked to winter snow depth on frozen lakes. These findings suggest that climate change may greatly affect habitat suitability for curlyleaf pondweed. As Minnesota lakes warm with less snow cover limiting light penetration, curlyleaf pondweed growth will likely increase. These observations form the foundation for targeted follow up studies that more precisely describe conditions limiting the growth and expansion of curlyleaf pondweed in north-temperate, North American lakes.

 

Later this winter, Ray will post a blog that goes in more detail about this long-established invasive aquatic plant and the potential for its management to positively affect water quality by reducing internal nutrient loadingIn a nutshell, the jury is still out and more robust monitoring and research is needed if Minnesota is to efficiently and wisely invest tax payer dollars dedicated to clean water work in the state.

Wednesday, November 28, 2012

Aquatic Plant Species Domination - Collaborative Research Using BioBase

Contour Innovations is proud to announce a collaboration among aquatic industry leaders to better understand aquatic species domination and lake ecosystem changes over time.


FIGURE: Left map: sampling points where Eurasian watermilfoil was present (yellow) and absent (X) during a survey on Gibbs Lake, Rock Co. WI (77 acres) in summer 2012.  Points are overlain on a vegetation biovolume “heat” map from passively collected sonar data and processed by ciBioBase.  Red colors represent vegetation that is growing near the surface.  Right map: Eurasian watermilfoil “Dominance” map rendered from both species survey and biovolume data.  Areas that are yellow and red areas where Eurasian watermilfoil is dominating the plant community and growing near or at the surface.

For over a decade, point-intercept survey methodology for aquatic plants has become a standard tool for lake resource managers and researchers.  The standard methodology entails sampling a uniform grid of points on a lake noting presence absence of species at each point with a rake. It is a relatively rapid way of objectively sampling aquatic plant species communities in a repeatable fashion.  However, the methodology’s primary downfall as a standalone method is its insensitivity to abundance of plants (i.e., 1 sampled sprig gets the same weight as a large bed at any one point).  Using passive collection of aquatic plant abundance with acoustics while conducting point-intercept surveys and simple GIS overlay methodology, we are demonstrating how species presence/absence layers can be combined with complementary biovolume (% of water column occupied by vegetation) data to form a more complete survey of both species AND abundance.  Further, using both species and abundance layers, we developed a ‘dominance’ index for each species sampled and demonstrate how dominance of any or all species can be used as an aquatic plant management or lake habitat monitoring tool.  Examples from Eurasian watermilfoil and Hydrilla infested lakes are used, as well as lakes with no known invasive species.   Future applications could utilize other environmental datasets (e.g., climate, land cover & use, water quality, etc.) to model the potential and realized outcome of a host of environmental stressors on the probability that invasive species will come to dominate a water body.

Aquatic biologist Ray Valley commented, "We're excited about where this research can take us.  Collaboration among experts throughout the US allows us to draw on a wide knowledge base and study ecosystems from a broad geographic range.  As this historical centralized dataset grows over the coming years, continued collaboration will help us understand and forecast true patterns in dominance and ecosystem effects of invasive species introduction."

If you have interest in participating in this collaboration or have suggestions, please contact Ray Valley at RayV@ContourInnovations.com

Participating Groups Currently Include:

Contour Innovations LLC, Minneapolis MN
University of Florida Center for Aquatic and Invasive Plants, Gainesville, FL
Wisconsin Department of Natural Resources Bureau of Science Services, Madison, WI
Minnesota Department of Natural Resources Fisheries Research Unit
North Carolina State University, Department of Crop Science, Raleigh NC


We'll keep you updated along the way!  Centralization is powerful stuff when it comes to aquatic plant research!

Monday, November 19, 2012

Lake Bottom Depth Precision and Accuracy

In an addendum to an earlier post, we continue to evaluate the accuracy and precision of BioBase depth outputs.  Lowrance has been in the depth sounding business since 1957.  They have tight factory calibration standards whereby depth should never be more than 2% different than the actual depth.  Of course then we expect depths to be spot on on hard bottom surfaces where truth can be easily measured.  But what about in mucky bottoms which are common place in many lakes, ponds, backwaters throughout the US and abroad?  With this in mind, in late May of 2012, we traveled to Pool 8 of the Mississippi River near LaCrosse WI to do some testing in a mucky, moderately dense vegetated backwater (Figure 1).  At some point we have to step back and ask, "what is the bottom of a body of water?"

Figure 1.  Vegetation cover and biovolume (% of water column occupied with vegetation) in Pool 8 of the Mississippi R. in LaCrosse WI on 5/29/2012.  Average biovolume was 30% during the survey.
The most difficult aspect of this testing was to get an objective estimate of the true depth.  In other words, where exactly did the plants end and bottom start?  Typically, investigators use a survey rod like that seen in Figure 2 to estimate actual bottom based on where they feel resistance on the survey rod.  Piece of cake over sand.  Not so easy over flocculant silt and muck or vegetative areas.
Figure 2.  Measuring bottom with a survey rod in a mucky Minnesota Lake.  Typically, the survey rod will sink several inches into the bottom before the surveyor feels resistance and judges the depth to the bottom

Many experienced surveyors will tell you that the rod will sink into the muck some distance before you feel resistance.  There is a positive correlation in the distance it sinks and how mucky the bottom is.  So, we went into this investigation expecting deeper rod depths measured than ciBioBase outputs. 

Accurate and precise results in mucky, vegetated bottoms

After 30 points measured with the survey rod, we compared the results with the ciBioBase depths measured in the same location.  We were pleased to see very high precision with a Coefficient of Determination (R^2) of 0.94 and a systematic difference in depth of only 4.9" (Figure 3).  The depth of 4.9" was quite possibly the average depth where we first felt resistance of the survey rod.  The upshot here is that ciBioBase depth outputs are highly precise, consistent and accurate even in mucky vegetated bottoms.
Figure 3. Accuracy and precision of ciBioBase depths measured against depths collected with a survey rod in the mucky, vegetated backwaters of Pool 8 of the Mississippi River near LaCrosse, WI.


Thursday, November 1, 2012

Mapping is Easier with Passive Collection

I remember the days when you had to schedule an hour out of your field day to “set up” and “take down” your mapping set-up.  Wires, an echosounder, a transducer, a GPS, a PC to run everything all had to be set up and configured (Figure 1).  Most importantly, equipment had to be secured by creatively fashioned brackets, booms, and working platforms so you didn’t lose a $4,000 part.  Many horror stories over the years have been told by colleagues who forgot “Righty” was “Tighty” and as a result dropped an expensive piece of fish structure in the drink!

Figure 1.  Elaborate set up of wires, brackets, and working platforms needed to operate the  hydroacoustic systems of yesterday
Needless to say, life during this period was about dedication.  A dedicated survey boat.  Dedicated surveys.  Dedicated staff to run the equipment.  Dedicated staff to analyze the data.  Dedicated staff to oversee that “Righty” made “Tighty” (ok, maybe not that bad).  But still, the expense and logistics of such dedication kept hydroacoustic mapping out of the reach of most water and fisheries resource entities.

With advances in consumer sonar technology, GIS and cloud-computing, now anyone can create high quality bathymetry, vegetation, and bottom hardness maps and datasets with a $700 Lowrance Depth finder, a canoe, and access to the internet with a subscription to ciBioBase (Figure 2).

Figure 2. A 3.6-acre storm water retention pond mapped in 30-min (upload processing time = 10-min) using a canoe and a portable Lowrance HDS-5.  Red lines are the actual traveled track along which data were collected and uploaded to ciBioBase for the generation of the bathymetric map.
Who needs dedication anyway?

No needs for a dedicated boat. The unit can be made portable with no larger than a 12” by 8” footprint (Figure 3).  The transducer(s) and optional GPS can be mounted on a bracket available from Cabelas (Figure 4).  This set up can then be put on a range of vessels from a canoe to a large cabin cruiser.  It can be checked out and passed around by lake association subscribers taking turns mapping the lake on which they live if they don’t already have an HDS.

Figure 3.  Lowrance HDS units can be made portable a variety of different ways to fit your budget and  sampling needs.
Figure 4. Example portable mounts for transducers 
No needs for dedicated surveys. Whether you are a lake association member drinking cocktails (while staying under the legal limit of course) on pleasure cruise on your pontoon or a biologist going point-to-point sampling species of plants, passively recording sonar data requires no work outside of hitting “record,” inspecting the screen for signal quality (i.e., a clear picture), and uploading the data when you return from the field.  ciBioBase algorithms rigorously evaluate the quality of each signal and filter poor outputs (Figure 5).  Back in the day, the staff hydroacoustician had to do this.  Computers do this now.

Figure 5.  Example of automated data quality filtering by ciBioBase.  In the top example, bass tournament anglers were rapidly hopping from spot to spot.  Vegetation detection becomes unreliable at speeds greater than 12 mph.  Consequently, outputs are not generated at speeds that exceed this threshold.  In the bottom example, depths were shallower than 2.4 feet and thus not mapped because of detection errors in depths shallower than this threshold.  However, manual waypoints can be added in these locations within users' ciBioBase account.
No need for dedicated staff trained in hydroacoustics and GIS.  Although ciBioBase offers much for the Hydroacoustic and GIS aficionados via data exporting and importing into their favorite data analysis software, training in hydroacoustics and GIS is not a prerequisite for creating good outputs and datasets.  Hydroacoustics and Geostatistics are not new or “soft” sciences that are so variable and complex that they can’t be automated (i.e., ecology).   The basic physics of sound traveling through water and reflecting off of various objects has been well understood for decades.  Concepts and applications of kriging (originally developed in the gold mining industry) are almost as old and well understood.  Accordingly, ciBioBase automates the interpretation of acoustic signals, creation of a GIS map layers, and standard summary reports.

Dedication in almost every aspect of life is an admirable virtue for which we all should strive.  However, when it comes to mapping lakes, rivers, or ponds, ciBioBase lowers the prestige of this virtue.  Indeed, there will always be a well-placed need for dedicated mapping.  However, we feel opportunities for understanding the dynamic nature of aquatic habitats will be missed if data are not logged while engaging in other activities on the water.  This is non-dedication at its finest!

Monday, October 1, 2012

Point-Intercept on Steroids

Who would’ve known that an obscure technical report describing a sampling methodology would become a classic in the world of Aquatic Plant Management and be adopted as a standard by lake service providers and government agencies?  Although it was old hat in the world of terrestrial Botany and Forest Ecology, Dr. John Madsen appeared to be the first to make point-intercept a standard tool for aquatic ecologists and lake managers with his Army Corps of Engineers Technical Note No MI-02 published in 1999 entitled “Point Intercept and Line Intercept Methods for Aquatic Plant Management.”

Briefly summarized, point-intercept methodology entails creating a grid of GPS points on a waterbody and traveling to those points and sampling the aquatic plants in those areas typically by throwing a double-headed rake and pulling up whatever it catches (Figure 1).

Figure 1. Contour Innovations Aquatic Biologists Jesse Amo (back) and Ray Valley (front) conduct a point-intercept vegetation survey while logging acoustic data on Orchard Lake, Dakota Co. MN.

The simplest and most objective application of the method is to simply record the presence of each species on the rake.  This does not lend much insight into how abundant each species is at each point and a mat of surface-growing vegetation gets the same weight as a lonely sprig (Figure 2).  To address this short-coming, several adaptations to the method have been made by various practitioners including ranking the abundance of different species on the rake.  Although some may argue it’s a "better than nothing” measure of relative abundance, I would argue, not much.  There is no straightforward way to objectively rank the abundance of 5 different species in a gob of plant matter on a rake like seen in Figure 1.  As a consequence, results are not repeatable and four different investigators could produce four different results for the same sample.  Further a relative ranking lends little biological information about the architectural structure or canopy height of aquatic plants.
Figure 2. Conceptual figure of a point-intercept sampling point in two contrasting environments.  In the pure application of the method, if the rake intercepts the diminutive sprig in panel B, it would be given the same weight as the thick mat in panel A.
Biological processes, water quality, physical habitat and recreational conditions all hinge on the state of aquatic plant ABUNDANCE in a waterbody.  As I have described above, point-intercept or any subjective adaptation is not well suited to address aquatic plant abundance concerns.  Nevertheless, point-intercept has many strengths and one shouldn't throw the “baby out with the bath water.”  Rather, ciBioBase offers a powerful and efficient way of getting more out of your point-intercept species sampling.

To add biovolume to your point-intercept surveys all you need is a Lowrance HDS depth finder, a $10 SD card from your favorite electronic retailer, and a subscription to ciBioBase (single lake and unlimited pricing are available).  No additional set up is necessary.  No technical mapping experience needed.  Just hit record, and jump from point to point like you've done in the past.  The HDS unit will passively record the GPS signal and acoustics the entire time.

After you return from the field, upload the data to ciBioBase, get a cup of coffee and catch up on some email.  Approximately 30-min to an hour later, one of the new emails in your inbox will be an alert from ciBioBase informing you that your plant abundance and bathymetric map is processed and ready for viewing.

Not only does passively logging sonar data while conducting species surveys require no additional work, but you sample important interim areas between points and get understanding of the TRUE coverage of plants (not just the frequency of plants sampled with your rake).

Unleashing the power of Point-intercept by using ciBioBase

Although ciBioBase comes with many analytical tools, its full potential to inform aquatic plant management is realized when the data is exported out of ciBioBase and into GIS for analysis with other data layers (Figure 3).
Figure 3. ciBioBase users have the option to export processed point data along their GPS track (Point) or  the uniform grid created by kriging interpolation (Grid).  Users can then import these files into GIS for further analysis with their point-intercept data layers.

By converting the ciBioBase grid text file into a Raster grid and using a “point on raster” analysis utility available both in ESRI’s ArcGIS and Quantum GIS (an open source GIS program), users can grab the biovolume value for a point-intercept sampling point (Figure 4).

Figure 4. Example of biovolume data (grid of blues, purples, and reds with increasing density or biovolume getting a "hotter" color) imported into GIS and overlain with point-intercept species data (yellow points are northern watermilfoil - a native stand-in for its unwelcome foreign cousin Eurasian watermilfoil).  The Point Sampling Tool in Quantum will extract grid values from one raster layer and attach them to a different point-layer.

In the hypothetical example in Figure 4, anywhere where milfoil is present we can see how dense the vegetation growth was at the sampled point and around it.  By using the Point Sampling Tool in Quantum that captures the biovolume grid cell value for each surveyed point, we found that for all milfoil points, average biovolume was 65% (with many points at 100% or surface growing).  For all other vegetated points, biovolume was only 45% with many less 100% values.

How can information on species abundance lead to better management decisions than presence alone?  It is generally unrealistic to eradicate most invasive species, and often a more realistic objective is to manage the abundance to an acceptable level.   Perhaps the surface growing tendency of milfoil (i.e., biovolume = 100%) is the primary management concern and that reducing “biovolume” to say, 45% with much less surface growth like other native plant species, would be a desirable result.   Presence/absence data from point-intercept surveys alone will not inform whether plant abundance is being managed within desirable levels.

Case Study: Whole-Lake Treatments of Fluridone with Both PI and Biovolume data

Valley et al. (2006) describe results of whole-lake applications of the herbicide fluridone to a nutrient-rich Minnesota Lake (Schutz Lake, Carver Co. MN).  As part of the evaluation, hydroacoustic surveys of vegetation biovolume were conducted before and after the treatments in addition to point-intercept species surveys.

The treatments reduced Eurasian watermilfoil below detection levels, but also directly or indirectly played a role in reducing the other dominant native species in the lake, coontail.  In fact, almost all submersed vegetation disappeared 1-2 years following the treatment; however, one would never get that indication by solely looking at the point-intercept statistics (Figure 5).  

Figure 5. Mean whole-lake percent vegetation biovolume from hydroacoustic surveys (bars) in Schutz Lake, Carver Co. MN from Valley et al. 2006.  Percent frequency of occurrence of all vegetation from point-intercept surveys conducted at the same time (numbers above bars).
What had occurred was a situation that went from Figure 1A to Figure 1B.  To a rake, these environments are the same, to a lake manager and concerned citizen, they are strikingly different.  Evaluating results with Point-intercept frequency sampling alone can mask unintended harm to water quality and lake resilience.

In the 2000’s, point-intercept methods gave resource managers an objective and rapid species assessment tool.  Now, ciBioBase adds a critical third dimension to these surveys with no additional effort or training. By implementing ciBioBase as a part of standard aquatic plant assessments, resource managers and citizens will be better informed about the true state of vegetation growth in a lake and how it’s changing as a result of environmental change and our management responses.


References
Madsen, J. D. 1999. Point Intercept and Line Intercept Methods for Aquatic Plant Management. APCRP Technical Notes Collection ERDC/TN APCRP-MI-02.

Valley, R. D., W. Crowell, C. H. Welling, and N. Proulx. 2006. Effects of a low-dose fluridone treatment on submersed aquatic vegetation in a eutrophic Minnesota lake dominated by Eurasian watermilfoil and coontail. Journal of Aquatic Plant Management 44:19–25.




Wednesday, September 26, 2012

Paradise Lake Improvement Board (MI)

Contour Innovations has recently adapted the ciBioBase platform and pricing options to support the mapping initiatives of local government units, home owner associations, and improvement boards.  One of the most recent additions to this project has been the Paradise Improvement Board in Carp Lake, MI (Lower Peninsula) and we're excited about it!*

The Paradise Lake Improvement Board (paradiselakeimprovementboard.com), through crowd sourcing and citizen science concepts, can now quickly determine the location and abundance of aquatic vegetation for management interventions and quantitative evaluation of the effectiveness of those techniques.   

There’s no technical expertise required!  Our biologists walked the volunteers of the PLIB through a demo account to demonstrate the key features for success with ciBioBase and discuss the recommended settings and collection techniques.    

 
 It's this simple

Led by board member Catherine Freebairn, the PLIB purchased 2 Lowrance™ HDS units that will be set up as portable units for the lake group and an unlimited upload subscription to ciBioBase.com.  These units will be used to map Paradise Lake during dedicated mapping time as well as during pleasure cruises with passive collection.  With each minute on the water, the PLIB volunteers will be collecting vital statistics on aquatic vegetation, bathymetry, water temps, water volumes, and water clarity, all by hitting "log sonar" on their new HDS sonar units.  All of this data will be stored in their private online account. 

Aquatic biologist Ray Valley commented, "Protecting our lakes demands understanding of what lies beneath the surface and how its changing as a result of environmental changes and our responses to them."

Using the innovative ciBioBase System, the PLIB has started building a historical database of their aquatic environment to monitor vegetation abundance and other important water quality characteristics over time.   They can now quickly determine the location and abundance of submerged aquatic vegetation for management interventions and quantitative evaluations of effectiveness of those techniques.  This database is the catalyst for efficient management today and in the future.  By gathering  this data each time someone is on the lake, the Board can crowd source the mapping effort and share information with their service providers for collaborative and objective decision making.  

“The PLIB has always shown a substantial passion for their lake and we feel that their early adoption of our powerful technology will be rewarded on many fronts,” said Contour Innovations’ CEO Matt Johnson.  “It’s very easy to work with groups like the PLIB who see the big picture in lake management and monitoring and want to see results.  They develop close relationships with their service providers and home owners to work hand-in-hand in understanding the best opportunities to reach their goals.  This is the first time that groups like this can use acoustics for accurate vegetation mapping and ciBioBase fits perfectly within their strategy,” he added.  

The PLIB will be working with their service providers (who will also have access to uploads and maps) to make important management decisions, monitor changes, and objectively evaluate if management interventions are having their desired effects.  With the support of all involved, including Contour Innovations’ own aquatic biologists, the future looks bright for Paradise Lake and anyone that enjoys all it has to offer!
 An Example of a Lake Mapped with ciBioBase
 Aquatic Vegetation Displayed in % BV (water column occupied by plants)

If you're interested in finding out more about ciBioBase and how it can help your association or improvement district, please contact us and we'd be happy to set up a person demo for you with one of our biologists.  Please contact Jesse Amo for additional details:  JesseA@ContuourInnovations.com

For more information on the Paradise Lake Improvement Board please check out their website at paradiselakeimprovementboard.com.

*Contour Innovations does not release personal information about our customers.  We obtained permission from the PLIB before this media release.

Friday, September 21, 2012

Precision Management-Time to Quantify

Lake Harriet Monitoring Before and After Harvester. . .

A multitude of factors impact the health of aquatic systems creating a need to monitor lakes’ “vital signs”.  In the same way it is expected that a medical doctor will do more than glance at a patient and say: “you look fine” the same is needed for our lakes.  A number of different vital signs are necessary to give a precise assessment of human health and our aquatic systems are no different, they are complex biological systems.  ciBioBase provides many “unchecked” parameters that have not been assessed until now in an automated processing system.  Two trips on a small section of Lake Harriet in Minneapolis collecting “vital signs data” have already told a story about big changes in the aquatic community.  What more can we learn about this complex ecosystem by simply monitoring with ciBioBase on an ongoing basis?

A data collection trip with ciBioBase in late June on Lake Harriet revealed what you might expect from an unseasonably warm spring in a lake infested with Eurasian watermilfoil (EWM).  Aquatic plant growth was several weeks ahead of schedule with EWM dominating the sample area on north shore and already being matted on the surface.  The majority of near-shore areas sampled exhibited near 100 % EWM biovolume (% water column occupied).  In fact, in the far east and west reaches of the sample area our survey-boat was skirting matted EWM too dense to navigate through.  Wherever vegetation occurred (percent area coverage) on the June 18th survey the biovolume average was very high, due to it being composed primarily of EWM (average of 54.4%).  

BEFORE:

 

In late August a comparison trip was completed, navigating the same transect line from the June trip using ciBioBase following the Lowrance HDS track overlay on the unit.  A striking feature noticed shortly after getting on the water was…..Where was all the topped-out vegetation?  The transect sampled on June 18th skirted topped-out EWM, but on August 22nd no topped-out vegetation occurred in the same sampling area.  This excerpt from the Star Tribune written by Bill McAuliffe on June 10th explains: “The Minneapolis Park Board's milfoil harvest began with a single mower.  . The harvesting each year generally requires at least two passes through each lake. Cedar Lake was scheduled for mowing Friday. After that, Lake Harriet is on the schedule.” (View the article by clicking here).  That would explain the drop in average biovolume in vegetated areas from 54.4% to 16% and overall average biovolume for the entire sampled area from 28.3 to 5.1%.


AFTER:

*Automated Reports Generated for Each Trip Uploaded to ciBioBase

ciBioBase not only displays that the average biovolume in vegetated areas for this study site dropped from 54.4% to 16% and overall average biovolume for the entire sampled area from 28.3 to 5.1%, but it also outlines vegetation distribution.  Spatial characteristics such as the shift from about 30% of the sampled area having a biovolume of  >80% to 0.34% of the sampled area having a biovolume >80% after the EWM harvest are also a part of the ciBioBase data output.

ciBioBase has enabled users to precisely compare changes in biovolume and spatial distribution of vegetation; pinpointing changes and quantifying their outputs.  This means precision monitoring and management using quantifiable target goals while leveraging objective “before and after” monitoring data that is easily collected, processed, and viewed with the ciBioBase system.

Knowing precisely “where and how much” are critical components to knowing if management plans are effective.  Another excerpt from Bill McAuliffe’s Star Tribune article states: “The Lake Minnetonka Conservation District launched its two mowers Thursday, about on schedule because it uses school teachers to run them, said Judd Harper, who manages the district's milfoil removal. But weed growth on the lake is "a lot worse than it was last year," Harper said.”  ciBioBase provides numbers behind “a lot worse”.

Using the ciBioBase system and historical database comparison, it is now possible to quantitatively identify year to year and other temporal trends.  Managers can now implement corresponding management based on sound scientific data and quantitative metrics.  ciBioBase is the key to precision management!

TRIP COMPARE FEATURE IN CIBIOBASE

* %BV (% of the water column filled with plants)

ANOTHER SHOT OF BAIT FISH PICKED UP BY STRUCTURE SCAN

 
ABOUT CIBIOBASE:

ciBioBase removes the time and labor required to create aquatic maps! The System was engineered to provide automated cloud based bathymetric and aquatic vegetation mapping and historical trend tools for aquatic habitat analysis. ciBioBase leverages log file formats recorded to SD cards using today’s Lowrance™ brand depth finders and chart plotters. Data you collect while on the water is uploaded to an online account where it is processed by our servers automatically! We rely on automation to make vegetation mapping cost effective by reducing the technical skills, staff, and hours to produce vegetation abundance maps from raw sonar collection. With the human element gone, you get accurate and objective mapping at lightening speeds! The result is a uniform and objective output all over the world!


Monday, September 17, 2012

What's this Kriging Business?!

Thanks to advances in Geographic Information Systems (GIS) computing technology, evaluating changes to lake bottoms over time has gotten much easier!  Prior to GIS, biologists and surveyors would go through great pains to ensure that repeated data collection in study areas of interest would precisely fall on the same area or transect.  If this condition was not met, data would have to be thrown out because biologists could never be sure that the difference seen between two time periods was real, an artifact of sampling a different area, or a product of sampling in a different way.  Consequently, efforts from multiple groups collecting similar data in the same system but in a slightly different way could not be leveraged.  This is an unfortunate missed opportunity that ciBioBase uniquely handles.

First, ciBioBase uniformly interprets acoustic signals and the output is the same regardless of the skill level of the individual collecting the data.  Second, ciBioBase employs kriging to create a statistically robust uniform map output that figuratively turns Survey 1 by Bob Smith from an orange into an apple and Survey 2 by Amy Johnson in the same area from a grapefruit into an apple.  This is unique to kriging which is a geostatistical procedure.  All other standard interpolation methods are simply 3D representations of the input data and each map will look different depending on the precise location of your survey points.  Only kriging turns different fruits into apples.

Kriging takes irregularly spaced data points and creates a smooth GIS map (also called a raster grid) based on the geostatistical properties of the input data.  Generally, points close together are more related than points farther away but the precise relationship can vary from location to location.  Kriging uses the actual statistical relationship of neighboring data points to make predictions in unsampled locations.  Other popular methods such as Inverse-Distance-Weighted (IDW) interpolation make simple assumptions of relatedness and does not use actual data to influence predictions in unsampled locations.

Through its use of kriging, ciBioBase removes the concern of precisely following the same path from survey to survey; which is very difficult to do on moving water even for the most seasoned surveyor.  Further this process can leverage passive data collection while doing other survey work, fishing, or simply enjoying a pleasure cruise and turn it into useful information for water resource management and protection (Figures 1-4).


Figure 1. Fisheries biologists can collect fish habitat data passively while conducting electrofishing fish surveys.
Figure 2. Passively collect depth and vegetation abundance data while enjoying a pleasure cruise with the kids or fishing.
Figure 3. Result of merged ciBioBase trip path data from passive data collection (above) resulting in a uniform vegetation map (below).
Figure 4. Zoomed in area of Figure 4 showing merged trip paths (above) and the uniform map output (below).  The heat map represents density of aquatic vegetation.  Blue is no vegetation growth and red represents vegetation growth that is all the way to the water surface.

Revised ciBioBase automated summary reports 
At 15 pings per second coming out of Lowrance HDS depth finders, data quickly add up and without any help, users can be drowning in data and be worse off than when they started.  This issue was the topic of a previous blog post (What to do with all this data?). ciBioBase handles the data deluge by using kriging and creating automated summary reports.  Our recently revised summary reports now include statistics based on coordinate point data (i.e., your trip path) and data from the bathymetric and vegetation grids created by kriging (Figure 5).  When survey data collection is structured with straight transects of a uniform speed (as in the case with Figure 5), the differences between the point and grid summaries is small.

Figure 5. ciBioBase automated summary report excerpt showing both coordinate point and kriging grid summaries
In circumstances where lake managers are primarily interested in monitoring vegetation along standard transects, the point summaries may suit them best since the points are often uniformly spaced a part and along a straight path (Figure 6).
Figure 6. Example automated summary report showing results from a standard transect survey.  Because data lie along straight paths and are mostly uniformly spaced, point data summaries should be used.

However, if you idle for long periods time collecting samples on the lake or trying to entice finicky fish to bite, many data points amass in one location (Figure 6) and can bias the statistics from the point data (Figure 7).

Figure 7.  Vegetation point data along trip path (blue) exported from ciBioBase and displayed in GIS at two zoom levels overlayed on uniform kriging grid data (blue-red).  Notice the accumulation of data points over areas where the boat is only slightly moving.  Kriging creates a uniform grid of points no matter how the data are collected.
In the situation above, the differences between the point and grid data are larger and the grid data becomes more important to use for formal statistical summaries and reports (Figure 8).  The upshot is when in doubt, use the grid statistics for your data summaries.


Figure 8. Differences between point and grid statistical summaries when data along trip path are not uniform. In these situations, use the statistics from the uniform grid for report summaries and lake management decision making.

A better use of your time
By automating the complexities of creating maps, ciBioBase users do not need to spend precious time and money dealing with manual data collection with survey rods and hand held GPS’s, entering data with a pencil onto a datasheet, and then figuring out how to display the data in GIS and run Geostatistics models to get a map.  Before BioBase’s launch in 2011, bottom and vegetation mapping was a costly endeavor and often just wasn’t done.  ciBioBase is changing the game and is empowering all citizens regardless of technical expertise with the ability to see what is below the water’s surface, how it’s changing over time, and how to best manage that change.

Friday, September 7, 2012

v2.0 Reports Are Live!

Despite the amazing mapping and visualization tools of BioBase and the questions they spark and help answer, the numbers and old fashioned summary data reports are often tough to beat.  Indeed, many of our users have found our automated summary v1.0 Report of BioBase outputs very helpful for objectively evaluating their aquatic plant management activities.  However, the focus of the version 1 Report was to produce a simple and uniform summary of data collected along users’ trip paths, which often occurred in the form of linear transects.  Sometimes the v1.0 Reports didn't support an apples to apples comparison.


As our user base expands into system mapping and crowd-sourcing efforts, where trip paths often resemble a bowl of spaghetti, leveraging the power of kriging interpolation becomes even more important.  As such, we've just released new automated summary Reporting (v2.0) that will publish both point (i.e., for classic transects) and grid (passive mapping or crowd-sourcing) summary statistics.  The version 2 Reports also output biovolume details in the vegetated areas only as well as within the complete survey zone.   Further, you will find statistics grouped by areas of interest and not only a summary of all data within the merged trips but a uniform summary of each transect that make up the merge!   They're pretty slick!

Our team has used their previous work experience and interaction with our users to develop reports that are relevant to a wide range of users including lake associations, lake service providers, agency biologists, or university researchers.  We hope you find these reports useful for your work.  Please let us know if you have any questions about how these Reports and data can be used.

You can view the full interactive report with collapsible sections and zoom by clicking here: REPORT SAMPLE   Each report gets a unique URL that can be emailed to customers,  or collaborators.

  Get the v2.0 Reports For Your Past Trips!

This is another great example of how a new feature can be associated to each of your previous uploads.  To get the new v2.0 Report for your previously uploaded trips, click on the Trip Reprocessing tab of the interactive viewer and select "Report" before clicking reprocess.   Try a merged trip first and let us know what you think!  Not a ciBioBase customer yet and don't have any trips to reprocess?? Why not?  Give us a call and you can join the revolution!

Friday, August 31, 2012

Contour Innovations' New Office

We recently came to the realization that we had outgrown our original office so it was time for an upgrade! Many of you that have been following our progress have seen that Contour Innovations has been hiring and growing as ciBioBase continues to expand its subscriber base across the world.  We're sad to leave the birth place of Contour Innovations but we've move into a great creative space in NE Minneapolis.  This move is an exciting event for CI!

    
Our new address:
Contour Innovations, LLC
1229 Tyler St. NE, #120   
Minneapolis, MN 55413

This is not a ping pong table, it's a morale booster . . . okay, it's a ping pong table:


If you have plans to be in the Minneapolis area, be sure to drop in and check out the new digs . . . and challenge us to a game!

About Contour Innovations, LLC:

Contour Innovations, LLC was founded in 2009 to develop a SaaS Platform for automated processing, interpreting, and centralizing a warehouse of industry specific GIS/spatial data.  We leverage this Platform to launch unique Systems that provide relevant information technology tools to different industries. Our initial systems are focused on acoustic processing of user collected sonar data.  Our first System launch with ciBioBase is already changing the world of aquatic habitat research!

About ciBioBase:

ciBioBase removes the time and labor required to create aquatic maps!  The System was engineered to provide automated cloud based bathymetric and aquatic vegetation mapping and historical trend tools for aquatic habitat analysis.  ciBioBase leverages log file formats recorded to SD cards using today’s Lowrance™ brand depth finders and chart plotters.  Data you collect while on the water is uploaded to an online account where it is processed by our servers automatically!   We rely on automation to make vegetation mapping cost effective by reducing the technical skills, staff, and hours to produce vegetation abundance maps from raw sonar collection.  With the human element gone, you get accurate and objective mapping at lightening speeds!   The result is a uniform and objective output all over the world!

Contact us for details about testing the System or checking us out in a demo account.  We also sell Lowrance HDS units to outfit your data collection boat!

Friday, July 20, 2012

Bathymetry Mapping with ciBioBase!

At Contour Innovations, we often preach the importance of aquatic plant mapping and monitoring, but of equal importance and capability is ciBioBase bathymetric mapping features.  ciBioBase comes with many features that automate the tedious, mundane, yet highly technical GIS processes associated with creating a bathymetric map.  Water resource and lake managers and researchers should be spending their time and talents focusing on thorny management problems, not compiling and managing volumes of data and trying to map them in GIS.  The science of acoustic bottom detection and GIS mapping has been extensively tested, verified, and proven with standard methods.  We automate this.

Because ciBioBase maps only areas you cover up to a 25-m buffer outside of your track, you are assured that maps do not include extrapolated data.  40-m spacing of transects with a criss-cross design assures you that you will get complete coverage and smooth contours (Figure 1). 
Figure 1. Transect coverage showing a "criss-cross" design to assure a high quality bathymetric map.

The Trip Replay feature in ciBioBase further allows you to see disruptions in the contours (Figure 2).  As in the case with Figure 2, there was a temporary disruption in the transducer signal, thus giving an erroneous depth (Figure 2 and 3).  In ciBioBase, these erroneous depths can be edited out; thus creating a smoother, more accurate bathymetric map and associated statistics.
Figure 2. Desktop verification of bathymetric outputs with ciBioBase's Trip Replay feature.
Figure 3. Areas of disrupted signal can be deleted and the trip reprocessed for a more accurate and smooth bathymetric map.
Other times, these little “donuts” occur because depths temporarily enter a different contour level (e.g., 3ft contours with series depths = 5.99, 6.0, 5.99, 5.98, etc).  Although the 6.0 depth is likely legit, it may be more aesthetically pleasing to remove the 6.0 depth to prevent the creation of a 6ft donut hole.

Once you are happy with the output with individual trips, you can merge them in ciBioBase to create a uniform output (Figure 4).
Figure 4.  Merging function in ciBioBase that allows users to merge individual files or trips into a single, uniform map.
Tying Bathymetry to a Benchmark Elevation
When mapping bathymetry, it may be important to tie the water level to a benchmark water level elevation.  In our Minnesota Lake example, we went to the Minnesota Department of Natural Resource’s Lakefinder website and found important water level information (Figure 5).  On 6/5/2012, we surveyed McCarron’s Lake in Ramsey County, MN.  On 6/7/2012, the elevation-corrected water level reported by citizen volunteers was  840.84 ft above sea level.  The Ordinary High Water Level  (OHW) benchmark for McCarron’s is 842.21 ft (Figure 5).  Using the Data Offset feature in ciBioBase (Figure 6), we can simply add 1.37 ft (elevation correction) plus 1 ft (transducer correction) to get a bathymetric map that is corrected to the OHW (Figure 7).  This eliminates water level as a confounding variable with repeated bathymetric surveys on the same waterbody.  The final products are high resolution, blue-scale imagery as seen in Figure 7 (up to 1-ft contours) or the actual point and grid data that can be imported into any third party GIS or statistical software (Figure 8).
Figure 5. Water level information for McCarron's Lake in Ramsey County, Minnesota USA.
Figure 6. Data Offset feature in ciBioBase that allows users to correct their bathymetric data to a benchmark water level and transducer depth.
Figure 7. Bathymetric imagery with resolution (both bottom and pixel) that can be controlled by the user.
Figure 8. Export point data along your traveled path or the kriging interpolated grid for use in third party GIS or statistical software.

Life is good in the cloud...

Because of the centralized, cloud-based platform of ciBioBase, we see trip uploads into the system from all types of lakes, ponds, and reservoirs throughout the country and even abroad; so our acoustic and geostatistic algorithms have seen it all!

See for yourself in our demo account at ciBioBase.com.  In the login page, enter demo@cibiobase.com and “demo” for the password.  Operators are standing by to answer any questions you may have!

Monday, July 9, 2012

Lake Mapping and 800 kHz DownScan

ciBioBase Now Offering 800 kHz DownScan in its dynamic Trip Replay feature.



Trip Replay is taking a leap forward with the new option to view your data using the 800 kHz DownScan option when recording with the StructureScan™ add-on.  Anyone that has been uploading data gathered with StructureScan™, by logging all channels, can now view past and future trips with this new feature.

You may have seen our earlier posts about the ciBioBase Trip Relay feature.  Your raw data collection is automatically processed by our powerful cloud servers and fully mapped with krigging algorithms and other geo-statistical considerations. Once processed, you can then replay the entire trip, watch your boat travel along your transects, and ground truth the % BV heat map with the water column cross section (on the right side of the image above).   This feature allows our customers to verify every trip output for accuracy and provide objective evidence for anyone that questions your aquatic vegetation maps!

The power and accuracy of the Lowrance™ HDS StructureScan™ allows us to offer a new and amazing cross-section view (DownScan) of the water column for each trip in the Trip Replay feature.  As you can see from the images below, this feature provides amazing views of bottom and vegetation.  It is even possible to notice changes in vegetation types or habitat cover type under your boat.  With our waypoint feature, you can identify vegetation transition zones and areas of interest for typing and delineation.



Please let us know if you would like to add StructureScan™ to your current data collection hardware.  Although not mandatory for using ciBioBase, this option can be added to any HDS™ system at any time for great views underwater.  For details on using or recording StrucutreScan™ please request a copy of our Standard Operating Procedures.


Another great feature added to the powerful ciBioBase System.

ABOUT ciBIOBASE

ciBioBase was engineered to provide automated cloud based GIS, aquatic vegetation mapping and historical trend tools for aquatic habitat analysis.  CI BioBase leverages log file formats recorded to SD cards using today’s Lowrance™ brand depth finders and chart plotters.  Data you collect while on the water is uploaded to an online account where it is processed by our servers automatically.   We rely on automation to make vegetation mapping cost effective by reducing the technical skills, staff, and hours to produce vegetation abundance maps from raw sonar collection. With the human element gone, you get accurate and objective mapping at lightening speeds!

Check out more anytime at ciBioBase.com and on our ciBioBase BLOG

Wednesday, June 27, 2012

Crowd Sourcing Lake Mapping


Natural Resource Managers and Climatologists have long recognized the critical importance of observer networks and volunteer citizen monitoring.   With citizen monitoring networks, Managers and Scientists acquire useful data for making more informed predictions and management decisions, while involved citizens gain an ownership stake in building the knowledgebase about the condition of ecosystems and the climate.

Citizen protocols for water quality (e.g., Secchi clarity) and meteorology (e.g., rainfall) data collection are largely objective and are becoming increasingly standardized throughout the nation.  As a result, comprehensive datasets are being merged at large geographic scales to assess the current status and trajectory of water resource and climate conditions.  Despite well-intentioned citizen programs to map and monitor aquatic plants in several US states, most are subjective and non-standardized.  Consequently, results will differ across surveyors, systems, and geographic regions.  This strongly limits the power and usefulness of data collected from these programs.   This is unfortunate because of the importance of aquatic plants for fish habitat and water clarity, and the vulnerability of lakes to invasive aquatic plants.

Contour Innovations has addressed this issue with ciBioBase and is poised to revolutionize citizen aquatic plant monitoring.

Objective data collection and analysis

Few others cover more water than citizens living on lakes.  Why not capture information about bottom conditions while on a pleasure cruise or fishing?  With only a modicum of planning, the lake could be divvied up among users to ensure consistent and uniform coverage.  By loading in a $10 SD card into the slot on a Lowrance HDS unit and hitting record while driving over areas of interest, lake citizens are well on their way to collecting important information on aquatic plant growth.  After a trip, citizens upload the recorded files to ciBioBase’s cloud-based servers which will trigger algorithms to automatically analyze bottom and plant signals, map the output and match it up with your sonar viewer (Figure 1).  Pretty maps? Absolutely! But also, objective statistical reports that summarize the plant growth conditions (e.g., percent cover, biovolume; Figure 2).  By sampling the same area over time, citizens can objectively monitor change as environmental conditions change.  Further, these efforts will provide objective benchmarks by which to evaluate watershed, shoreline, and in-lake management efforts. 

Figure 1. Automated mapping of bottom and vegetation signals matched up a high resolution DownScan sonar trip replay. 
Figure 2. Excerpt from ciBioBase automated statistical summary report.

Data that most closely corresponds to water quality, fish habitat, and nuisance conditions

Prior to ciBioBase, lake citizens, service providers, and natural resource agencies had little choice but to express plant growth in the lake as “abundant” or “sparse” with sophistication ranging up to digitally drawn maps around the outside of plant beds that they could see from looking over the side of the boat or from an aerial photo.  Anything that could not be seen with the naked eye or from an aerial photograph was ignored.  Quantification was limited to what could be pulled up with a rake and expressed as a presence/absence  metric of frequency of occurrence.

From a water quality and fish habitat perspective, these methods have left the fishery and water resource manager, lakeshore owner, and angler wanting.  Traditional plant assessment methods as described would give the same value to the strikingly contrasting environments depicted in Figure 3).  In the panel on the left, plants only occupy approximately 60% of the water column.  There are adequate hiding places for prey and room for predators to swim around in search of prey.  Plants are adequate to anchor sediments and prevent stirring of sediments that can make the lake murky.  Last but not least, a boat can easily pass through without disturbing the habitat.  Contrast this with the panel on the right.  Although the visual delineation or rake throw prescribed by traditionalists would give the same information on density as the panel on the left, fish habitat and water recreation conditions are strikingly different between the two environments.  In this simulated invasive aquatic plant community (e.g., Eurasian watermilfoil or Hydrilla) without any edge, predatory fish have difficulty finding prey, boat propellers are stopped in their tracks and outboard impellers imperiled!  Essentially, the differences described between the environments in Figure 3 can be summarized in the ciBioBase biovolume maps and statistical outputs.  Ask your service provider or local water resource manager how they measure aquatic plant growth conditions in your favorite lake and evaluate whether they stack up to what ciBioBase provides.

Figure 3.  Contrasting aquatic plant environments that are often represented equally in traditional assessment methods.  On the left is growth that typifies a diverse, native aquatic plant community as opposed to topped-out growth that typifies invasive plant communities.  By mapping biovolume (percent of water column occupied by vegetaton), ciBioBase distinguishes the differences between these plant communities.
Centralized database – Apples to Apples

All data uploaded to ciBioBase are processed uniformly in a centralized database and made available to subscribers in a private organizational account.  Data from Lake Minnetonka in Minnesota can be compared with data from East Lake Tohopekaliga in Florida or data from Esthwaite Water in the UK and comparisons will be apples to apples.  The centralization feature of ciBioBase comes with these tangible benefits as well as intangible ones like fostering greater collaboration between groups interested in aquatic resource conservation.

Merged uniform outputs from multiple surveyors

A new buzzword has been entering the vernacular of natural resource managers called “precision conservation” brought on by advances in aerial photography, lasers (LiDAR), automated sensors, and greater computing power.  We can now identify miniscule areas on the landscape that are sources of runoff and pollution and strategically target those areas to install “Best Management Practices” or BMP’s like rain gardens or grit chambers.  However, thus far the dialog surrounding precision conservation has largely been terrestrial.  ciBioBase is bringing precision conservation to lakes through its merge trips function (Figure 4).

As ciBioBase account managers our users can compile trips from subscribers within their  organization to create a highly precise map of bottom and vegetation (Figure 4).  This division of labor describes the essence of this blog’s title whereby the collective efforts or intelligence of the many are more powerful than any one individual.  No one person is willing or able to track how the lake is changing from day to day as runoff from an increasingly common 4-in rain comes streaming (literally) in, but a dozen active citizens might.  The result is a near real-time data feed on changes in lake conditions that will greatly inform how the lake responds to environmental change, where to target conservation efforts, and whether implemented management policies are producing their desired effects.
Figure 4. Multiple citizens in the same organization can work together by merging trips, thereby creating the most accurate bottom and plant map on the face of the planet!

Wednesday, June 6, 2012

Aquatic Plant Abundance Mapping and Resilience!

Merriam-Webster Defines resilience as an ability to recover from or adjust easily to misfortune or change.  Eminent University of Wisconsin-Madison Ecologist Dr. Steve Carpenter further adds that resilience is the ability for a system to withstand a “shock” without losing its basic functions, http://www.youtube.com/watch?v=msiIV5NdLVs

Resilience is a relatively easy concept to understand, but it can be difficult to measure in lakes without monitoring subtle changes over time.  This stresses the importance of long-term monitoring and being on guard for new changes to water quality, aquatic plants, and fish.  Volunteer networks and agencies across the country are making great strides in monitoring water quality by dropping a disk in the water and scooping up some water and sending it to a lab for analysis.  In essence, taking the lake's "blood" sample.  Indeed, water quality samples can be very telling.  But what is happening to the rest of the lake "body"?  How is it changing in relation to its liquid diet of runoff or medication to treat invasive species?  Unfortunately, until now, natural resource agencies, lake managers, and volunteers have not had the capabilities to objectively and efficiently assess these changes without time-intensive, coarse surveys of vegetation cover.

Your body’s immune system is the engine of resilience.  When your immune system becomes compromised, you become vulnerable to a wide range of ailments that may not be a threat to someone with a healthy immune system.  The same goes for lakes.  In the glaciated region of the Upper Midwestern US and Canada, healthy lakes are those that have intact watersheds where the hydrologic cycle is in balance.  Without going into great depth, keeping water where it falls (or at least slowing it down), goes a long way in keeping the hydrologic cycle in balance.  Healthy glacial lakes also have clear water, a diverse assemblage of native aquatic plants, and balanced fish communities.  When humans or the environment alter any one of these components, the lake must adjust in order to compensate for those alterations and remain in a healthy state.  The ability of the lake to do so is this concept of resilience (Figure 1).

Figure 1.  Conceptual diagram of a resilient system.  The height of the slope and the deepness of the valley are the compensatory mechanisms that bring a lake back to some resilient baseline condition after a short-term "shock" like a flood or a temporary septic failure.  Lakes with forested watersheds, clear water, native aquatic plants, and balanced fish communities are typically in this condition.

Slowly, as more curb and gutter goes in, green lawns replace native grasses, personal swimming beaches replace marshes, fish are overharvested or overstocked, or invasive species are introduced, the lake slowly loses its ability to compensate (Figure 2).  All of a sudden you hear “I’ve never seen that before” become more common when people describe a phenomenon on the lake that well, they’ve never seen before.   You may start to observe more algae blooms, more attached algae on rocks and plants, plants growing where they’ve never grown before, invasive species taking hold and thriving.  This is an example of the lake losing resilience and succumbing to the vagaries of the environment.  Under these circumstances, the lake can’t compensate anymore and you never know what you will see from year to year.  With no baseline, objective assessment of aquatic plant abundance and no monitoring of change in abundance and cover from year to year, it makes it even harder to know how much the lake has actually changed and what you need to try to get back to with implemented best management practices .

Figure 2.  An example of the consequences of the cumulative impacts of environmental and human stressors on lake resilience.  As lakes become more impacted by various watershed and in lake practices and invasive species, resilience is slowly worn away.  The valley becomes more shallow and a new "domain" enters the picture.  Lake conditions slosh around from one state to the next depending on the vagaries of weather and other disturbances.  Not knowing to expect from one year to the next becomes the norm.

A demonstration of the difference between a resilient lake and one that is losing resilience can be found in a paper published by Valley and Drake in Aquatic Botany in 2007 entitled “What does resilience of a clear-water state in lakes mean for the spatial heterogeneity of submersed macrophyte biovolume?”  Valley and Drake found very consistent patterns of vegetation growth from one sampling period to the next over three years in a clear lake (Square Lake, Washington Co. MN USA; Figure 3).  Each survey in Figure 3 took two days to survey and another week to make these plots.  Not including time on the water, ciBioBase produces these same plots in an hour.
 
Figure 3.  Submerged aquatic plant biovolume (% of water column inhabited by plants) as a function of depth in Square Lake, Washington Co., MN USA.  Notice the consistency of the pattern of vegetation growth from one time period to the next (study took place for 3 years from 2002-2004; Valley and Drake 2007).  Water clarity in Square Lake is high with diverse aquatic plants.
In contrast, patterns of vegetation growth were quite variable in a moderately turbid lake with abundant Eurasian watermilfoil; West Auburn Lake, Carver Co. MN USA; Figure 4).  For example, in summer 2003, a bloom of attached algae formed on Eurasian watermilfoil stems and effectively weighed down the stems and prevented them from reaching the surface.  This bloom was unique to 2003 and was not observed at any other time during the study.

Figure 4.  Plant growth as a function of depth in a moderately turbid Minnesota Lake with abundant Eurasian watermilfoil (West Auburn Lake, Carver Co. MN USA; Valley and Drake 2007).  Plants grew shallower and more variable in this more disturbed lake. 

If stressors continue unabated, then the lake can “tip” into a new, highly resilient domain of poor health (Figure 5).  The feedback mechanisms that used to keep the lake in a healthy state have now switched to new feedback mechanisms that are keeping it in an unhealthy state.  Algae begets more algae, carp beget more carp, stunted bluegill beget more stunted bluegill, if invasive plants are lucky enough to grow, they beget more invasive plants.  Getting the lake back to the original state is nearly impossible at this point.  It’s like Sisyphus rolling the rock uphill only to have it roll right back down again!  Although controversial, at some point, citizens, regulators, and lake managers need to start rethinking expectations and adapting management approaches in highly degraded systems.  Rather than trying to restore a lake to a Pre-European settlement condition through expensive, risky, and Draconian measures, it may be more reasonable to ask: “How can we have good enough water quality to support naturally reproducing stocks of game fish?”  “Can we manage invasive plants in a way that maintains fish habitat AND recreational opportunities?”  After the wailing and gnashing of teeth subsides and some agreement is reached on objectives and management strategies, then it becomes essential to determine whether implemented management practices are having their desired effect.  It doesn't take two weeks and $10's of thousands of dollars to do a vegetation survey.  Volunteers can do it, lake consultants can do it, state agencies can do it and they'll all do it the same objective way with ciBioBase and they can all work together!


Figure 5.  Example of a lake that has flipped into a degraded regime regulated by new feedback mechanisms that keep it in the degraded state. 

The Upshot

Resilience is an easy concept to understand on a basic level, but hard to measure in lakes and changes slowly over time.  This stresses the importance of long-term monitoring and being on guard for those things “you’ve never seen before.”  Uploading data to ciBioBase every time you are on the water gives an objective and quantitative snapshot of the current conditions in your lake of interest.  Be watchful for anomalies in monitored areas.  Vegetation growth should follow a relatively predictable pattern from year to year and if it doesn’t, that may be the first indication that the lake is losing resilience and precautionary conservation measures should be taken.  Conservation measures may include better onsite storm water infiltration (e.g., rain gardens, nearshore vegetation buffers), maintaining a modest amount of aquatic plant growth in the lake, maintaining a balanced fish community in terms of species, size, and abundance.  These efforts will go a long way in protecting the long-term integrity of our beloved lakes!

Suggested Readings:

Carpenter, S.R., 2003. Regime shifts in lake ecosystems: pattern and variation. In: Excellence in Ecology, vol. 15, Ecology Institute Oldendorf/Luhe, Germany.

Scheffer, M., 1998. Ecology of Shallow Lakes. Chapman and Hall, London.

Valley, R.D. and M.T. Drake 2007.  What does resilience of a clear-water state in lakes mean for the spatial heterogeneity of submersed macrophyte biovolume? Aquatic Botany 87: 307-319.