How BioBase is Helping Fish Conservation

BioBase EcoSound is helping State Fisheries Departments and Research Institutions across the US and UK to better manage Fisheries by providing important information about fish habitat.  See below for a short description of these ongoing investigations.Precision bathymetric mapping to estimate concentrations of a fish toxin (rotenone) to kill invasive fish in a Nebraska backwater lake. … Continue reading “How BioBase is Helping Fish Conservation”

BioBase EcoSound is helping State Fisheries Departments and Research Institutions across the US and UK to better manage Fisheries by providing important information about fish habitat.  See below for a short description of these ongoing investigations.

Continue reading “How BioBase is Helping Fish Conservation”

ECU Research on Lowrance/BioBase Effectiveness for Seagrass Mapping

Read about exciting new research by Dr. Joe Luczkovich’s lab at East Carolina University demonstrating rapid, precise and cost-effective acoustic techniques for mapping seagrass habitats in North Carolina USA’s Coastal Estuaries.  Dr. Luczkovich and undergraduate research assistant Audrey Pleva talk about the very high accuracy of Lowrance HDS and BioBase for seagrass in shallow areas of Jarrett Bay, Blount’s Bay, and Currituck Sound compared with underwater videography

Below is the abstract from: Audrey Pleva and Joseph Luczkovich.  2013. Effects of salinity on submerged aquatic vegetation’s growth and abundance in North Carolina and assessment of a SONAR’s accuracy to measure vegetation. Unpublished report, Department of Biology,  Institute for Coastal Science and Policy, East Carolina University, Greenville, NC 27858.  Contact Dr. Luczkovich if you have questions or would like a copy of the report.  Contact Navico to get updated (cheaper) pricing from what is cited in the report and to get you started assessing seagrass habitats with Lowrance/Simrad and BioBase!

ABSTRACT

 Submerged aquatic vegetation (SAV) is one of the most important estuarine habitats supporting commercially and recreationally important fishes and invertebrates, providing species food and shelter from predation. Salinity levels, an important factor in SAV growth and survival, are rising in North Carolina due to sea level rise bringing salty water from the Atlantic Ocean into NC, posing a threat to freshwater species. SAV species adapted to a certain salinity level are stressed by long and short term changes in salinity, resulting in patchy or smaller beds. In this project, a recently developed survey technique based on a combined video and echosounder system was used to measure the SAV % cover at three sites, each with different long-term and short-term salinity levels. Our hypothesis was that large short-term changes in salinity would be a stressor for SAV, and that as the range in salinity and the average long-term salinity increased, SAV % cover would decrease. We measured changes in water quality including salinity, temperature, and dissolved oxygen, and SAV cover using boat-based SONAR techniques at Jarrett Bay (JBS), Blount’s Bay (BLB), and Currituck Sound (CTS) in North Carolina during the beginning of the growth season where salinity is a very important growth factor. SONAR data were collected along 30 transects at 10-m intervals across the study area at JBS and BLB, but 60 transects at 25-m intervals at CTS. The accuracy of the SONAR technique was assessed using underwater video at 100 randomly selected points along transects at each site. Accuracy was very high (87.8 %) and relatively equal between all three sites. The salinities and % cover were highly variable among sites, in both the short- and long-term measurements, allowing for an analysis of the relationship between SAV and salinity. Overall mean long-term salinity was negatively correlated (r = -0.7) with SAV percent cover. Short-term salinity increases may cause declines in SAV cover, as freshwater species are displaced by salinity-tolerant SAV species.
Example image of seagrass abundance (% of water column with vegetation) in Currituck Sound, North Carolina.  200 khz Sonar image from Lowrance HDS (right) is coupled and synced with kriging interpolated map of vegetation abundance (left).  Areas of red are where vegetation is growing to or near the surface.  Areas of blue are bare.  Green and yellow is lower lying vegetation.  Datasets are summarized in BioBase with several analytic tools, but spatial data can also be exported for analysis in any third party GIS or statistical analysis platform.

See an online pdf of a presentation recently given by Dr. Luczkovich describing some of these results.

Platypus Offers New Opportunites in Pond Mapping

Researchers Paul and John Scerri and their team at Carnegie Mellon University have developed an autonomous vehicle called Platypus that can be used for a wide variety of aquatic applications.  One application we see customers struggle with is mapping small ponds.

Platypus getting fitted with a Lowrance HDS and transducer

Recently, the Platypus development group teamed up with Tim Wood at Aquatic Edge Consulting and Contour Innovations to test the use of a Platypus for sonar data collection and bathymetric and vegetation mapping of a pond.  They rigged up the autonomous vehicle with a small Lowrance HDS 5 and sent it into the waterbody.

Getting the data collection process going and testing while on the water

 

A close-up view of Platypus

They quickly acquired the data set recorded to their SD card, uploaded the .SL2 files to their account at www.BioBase.com and within minutes all of their files were done processing and could be merged into a full map.  The pond map output looks great!

You can check out a video of the operation here: Platypus in action

Platypus gathering sonar data for BioBase

Customers were happy, no one got wet, and the results speak for themselves.  Great job guys!

If you have an innovative way of collecting data for processing with BioBase, let us know and we’d  be happy to help!

New Survey Findings: Use of Geographic Information Systems by Fisheries Management Agencies

Recently Brandon Eder from the Nebraska Game and Parks Commission and Ben Neely from the Kansas Department of Wildlife, Parks, and Tourism published some interesting findings in Fisheries pages 491-495 regarding the use of GIS in fisheries management agencies in the US and Canada (see abstract below).  Technology is opening horizons and aquatic resource practitioners now have a variety of intuitive tools at their disposal to characterize and describe the complex spatial environments they are charged with managing.

Better characterization and description of aquatic environments leads to better management decisions and public welfare.  How can we promote more academic training and utilization of GIS tools for aquatic resource practitioners?  Eder and Neely have some advice that is worth a read.

ABSTRACT: Use of geographic information systems (GIS) in fisheries science has increased in prevalence since its introduction in the late 1980s, but use among and within fisheries management agencies has not been quantified. We surveyed 89 administrators of fisheries management agencies in the United States and Canada to determine the current status of GIS in fisheries management and received 54 responses (61% return rate). Survey respondents indicated that GIS was used to help manage fish populations, and 63% of respondents believed that GIS was either “very useful” or “extremely useful” for meeting agency objectives. However, most GIS work conducted by fisheries management agencies was executed by few individuals within the agency or by contracted service. Barriers preventing more widespread use by managers within agencies included lack of knowledge or training and limited time to use GIS in job duties. Our results suggest that GIS is an important tool for fisheries management. Further, GIS use within an agency might be increased by focusing on increased biologist participation in training exercises, integration with existing job duties, and recognizing diversity among GIS software.

Optimal Percent SAV Biovolume? 50% is a Good Start

At Contour Innovations we’ve long argued the importance of objectively assessing submersed aquatic vegetation (SAV) abundance to better inform management decisions.  Our last blog post discussing a recent controversy over the role of herbicides in indirectly affecting fisheries declines in Wisconsin reinforces why this is so important.  When we talk abundance per se, we need a metric that is quantitative, yet is intuitive.   The percent of the water column taken up by vegetation growth (i.e., percent “biovolume”) represents such a metric and is the primary variable that is mapped in ciBioBase.  Zero means no growth (blue).  100% represents growth all the way to the surface (red; Figure 1).

SAV, Aquatic Vegetation map, Lowrance HDS, Surface growing vegetation
Figure 1. SAV Biovolume map (left), boat tracks (red lines), boat location (red dot), and sonar chart of vegetation growing to the lake surface on Orchard Lake, MN.

Zero is undesirable in lake environments where vegetation growth is natural or where an artificial lake is managed for vegetation-dependent fisheries (e.g., largemouth bass or northern pike).  No vegetation growth can also cause and be an effect of water quality impairments as discussed here).  In contrast, 100% is undesirable from an aquatic recreation standpoint because props get tangled up and it’s difficult to navigate your boat through surface mats of vegetation (Figure 2).

Figure 2. Aquatic Vegetation (100% Biovolume) growing all the way to the water surface on Orchard Lake, MN and impediments to motorized recreation. 

If no plant growth is bad (0%), but plant growth all the way to the surface (100%) is bad, then good MUST be somewhere in between.  Indeed!  From a Fisheries standpoint, 40-60% average biovolume is good because there is habitat for vegetation-dependent species like largemouth bass, bluegill, northern pike, and indicator species like blackchin shiners that are sensitive to vegetation loss (Figure 3).

Figure 3.  Probability of sampling blackchin shiners as a function of increasing SAV % biovolume  in Square Lake, MN (Adapted from Valley et al. 2010 Hydrobiologia 644:385-399)

From a water quality standpoint, 40-60% biovolume is sufficient to anchor sediments and will promoting better water clarity than if nothing was growing.  Finally, 40-60% biovolume means that most growth is below the depth of your outboard prop and thus you generally won’t encounter the situation as seen in Figure 1.

A case study in MN, WI, NC, and FL lakes

CI is currently involved in a collaborative research project where acoustic data with Lowrance HDS was passively collected while conducting point-intercept surveys.  Acoustic data (.sl2 files) were uploaded to ciBioBase and the Biovolume value for each species survey point was extracted from the exported raster grid (“Extract Value From Point” in the Spatial Analyst Toolbox in ArcGIS or see our Point-Intercept on Steroids blog).  Figure 4 displays a wealth of information about the status of plant growth and management in the surveyed lakes.  With on-the-fly data entry for the plant species surveys and uploading of the .sl2 file to ciBioBase, a similar graph could be produced within hours of finishing a survey, and thus facilitating informed and rapid decision making.

Figure 4.  Biovolume at invasive species sample points and native sample points free of invasive species.  Non-vegetated sites are not included in the analysis.  Lakes range from intermediate nutrient levels, Mesotrophic (M), to high nutient levels, eutrophic (E).  Berry, Gibbs, Swan, Wingra, and Round are in WI; Gray’s, Gideon’s, and St. Alban’s Bays are bays of Lake Minnetonka, MN; Waccamaw is NC; Tracy, Kissimmee, Istokpoga are FL lakes.  All MN and WI lakes are infested with Eurasian watermilfoil.  All NC and FL lakes are infested with Hydrilla.  Waccamaw is bog stained and the hydrilla is a recent infestation

Specifically this graph tells us the following:

  1. Invasives grow closer to the surface of lakes than natives and growth seems to be highest in lakes of intermediate productivity (meso-eutrophic)
  2. Natives appear to grow at the 40-60% biovolume level regardless of productivity.
  3. Native growth can be an objective benchmark from which to judge the success of invasive management in non-eradication management regimes.
  4. Aquatic Plant management was successful at bringing down invasive growth to the level of natives in Gray’s Bay of Lake Minnetonka, Kissimmee, and Istokpoga
Something as simple as what is displayed in Figure 4 can bring an objective point of reference to the table when discussing the often controversial nature of aquatic plant management.  With data such as these, discussions by various user and management groups can center on the acceptable level of growth to meet Fisheries, Water Quality, and Invasive Species management goals (which we argue can occur at some intermediate level of plant growth).  Without both species AND abundance data, various factions will continue to take up positions with anecdotal evidence that support their prejudices and the discourse will never get to where it needs to be to tackle these important water resource issues.

Legacy applications of commercial sonar

At Contour Innovations we stand on the shoulders of giants who proved commercial depthfinders are precise scientific instruments for the measurement of aquatic plant abundance and distribution in lakes.   As early as 1980, researchers saw the potential for fathometers/chart recorders/depth finders/sonar/echosounders – whatever you want to call them – to substantially reduce time, effort, and cost in assessing aquatic plant communities in lakes (Maceina and Shireman 1980).

The commercial sounders of the 1980’s had only a fraction of the power and resolution of what Lowrance manufactures today (not to mention integration with GPS) and investigators still boasted of the quality and cost-effectiveness of the data acquired.  Here are some excerpts:

Maceina and Shireman (1980): “The principle advantage of utilizing a recording fathometer for vegetation surveys is that savings in time and manpower can be accomplished.  In Lake Baldwin, 14 transects covering a total distance of 11.3 km were completed in three hours.” p 38.

Duarte (1987): “Direct harvesting is an expensive and time-consuming procedure (see Downing and Anderson 1985).  Two SCUBA divers require 20 min on average to harvest the biomass of six replicate quadrats at a single depth.  In contrast, six replicate echosounder transects require only 8-35 min to obtain biomass estimates for all depths, with the actual time required dependent on the littoral slope and the depth to which the plants grow.  Additional advantages of the echosounder method are (1) a continuous record of the vegetation, rather than at discrete depths only, with the latter resulting in inaccuracies when the mean biomass values are estimated, (2) nondestructive sampling, which allows monitoring of the growth of stands over time and (3) simultaneous recording of other variables such as percent cover (Stant and Hanley 1985), volume occupied by the submerged vegetation, and littoral slope (Duarte and Kalff 1986), which influences macrophyte biomass.” p. 734

In fact, Duarte (1987) publishes biomass prediction equation from acoustic estimates of plant height (a ciBioBase output) for 22 aquatic plant species.

Thomas et al. (1990): “Fortunately, shallow range (0-7 m) chart recorders are standard on many low cost (less than $400) commercial echosounders, so the data acquisition equipment costs are relatively low with respect to fisheries acoustic assessments, which makes this procedure relatively nontechnical and very cost effective” p. 810

The concept of using commercial acoustics for mapping lake bottoms is established and proven.  Contour Innovations has refined, streamlined, and automated the methodology with ciBioBase and delivers an intuitive visualization of the complex underwater world we call littoral zones.

A Raytheon DE-719 “fathometer” relic when plant biovolume was measured on paper charts with the use of planimeters.  Photo from www.euronet.nl.
Paper chart from a Raytheon DE-719 displaying dense hydrilla canopies and bottom in a central Florida lake.  Reproduced from Maceina and Shireman 1980; J. Aquat. Plant Manage.

Classic Literature
Duarte, C.M. 1987. Use of echosounder tracings to estimate the aboveground biomass of submerged plants in lakes. Canadian Journal of Fisheries and Aquatic Sciences 44: 732-735

Maceina, M and Shireman, J. 1980. The use of a recording fathometer for determination of distribution and biomass of Hydrilla. Journal of Aquatic Plant Management 18:34-39.

Maceina, M.J., Shireman, J.V., K.A. Langland, and D.E. Canfield Jr. 1984. Prediction of submerged plant biomass by use of a recording fathometer.  Journal of Aquatic PlantManagement 22: 35-38.

Stent, C.J. and Hanley, S. 1985. A recording echosounder for assessing submerged aquatic plant populations in shallow lakes. Aquatic Botany 21: 377-394

Thomas, G.L., Thiesfeld, S.L., Bonar, S.A., Crittenden, R.N., and Pauley, G.B. 1990. Estimation of submergent plant bed biovolume using acoustic range information. Canadian Journal of Fisheries and Aquatic Sciences 47: 805-812.

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.

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!

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.


Analysis of Alternative Mapping Methods

Budgets are tight, time is short, labor resources and technical know-how are scarce.  These truths are the motivating force behind the ciBioBase system.  Recently, we ran an analysis that demonstrates the cost-effectiveness of ciBioBase.  We selected 3 peer-reviewed studies that demonstrated three alternative methods for whole lake assessments of vegetation abundance and compared the costs of producing a vegetation biovolume map with ciBioBase.  The first two studies Valley and Drake (2007) and Sabol et al. (2009) used a scientific-grade echosounder, associated software, and required expertise in hydroacoustics and Geographic Information Systems (GIS).  Hardware and software costs were adjusted to 2012 dollars which actually brought costs down to a total of $18,400.  These costs were amortized over 5 years at 5% interest and scaled to daily costs assuming use in a season would not typically exceed 45 days.  For both methods, hardware and software costs amounted to approximately $84 a day.  We did not factor in time on the water for any of these analyses, or the cost of training in hydroacoustics, geostatistics, and GIS.

Labor costs were relatively large in the Valley and Drake (2007) study because the authors were working in environments that exceeded the capability of the vegetation-detecting algorithm they were using.  Specifically, noisy signals generated in surface-growing vegetation canopies were thrown out and thus biasing biovolume (i.e., percent of the water column occupied by vegetation) downward.  Consequently,  Valley and Drake did ping-by-ping verification and reclassification where signals were obscured by surface-growing vegetation.  Summing the modest hardware and high labor costs to manually verify thousands of pings, the cost of producing a vegetation map in a 500-acre lake using methods described in Valley and Drake (2007) was approximately $1,288.

Labor costs were significantly lower in the Sabol et al. (2009) investigation because we assume vegetation did not grow to the surface in the Wisconsin study lake during the investigation and thus the vegetation algorithm processed individual files relatively quickly.  Taking the labor costs (10 hrs @ $25/hr) in Sabol et al. (2009) and adding in adjusted amortized hardware and annual maintenance costs, the costs of producing a map on a 500-acre lake was a much lower $357 compared with Valley and Drake (2007).
The third study evaluated the LAKEWATCH volunteer lake monitoring program administered by the University of Florida.  LAKEWATCH utilizes commercial-grade Lowrance sonar units to log data on bathymetry and vegetation height/biovolume (otherwise known as percent volume inhabited; Hoyer 2009).  Entry-level technicians analyze 100 random points from pooled transect files and record depth and estimate plant height to get a lake-wide estimate of percent area covered by vegetation and percent volume inhabited with aquatic plants.  Although the objective of LAKEWATCH is not to create high resolution vegetation maps, in order to make apples-to-apples comparisons, we had to scale-up the Hoyer (2009) method to reflect the same survey resolution (16,383 points) of the previous two methods.  This resulted in an incredibly high cost of $6,884 to produce the same type of vegetation map as described with the previous two methods.
ciBioBase 
Because we automate the analysis and mapping of vegetation, there is very little labor outside of conducting the survey, save for a recommended hour of reviewing the data after a trip and verifying the output.  Also, the hardware and software costs are minimal because we analyze data from Lowrance HDS-line sonar systems that are coupled with differentially corrected GPS systems and retail for $700-$2200.  Running the same calculations as the other methods, we estimated the per survey day cost of mapping a 500-acre lake was a very low $125; 2.8 times cheaper than the next lowest described by Sabol et al. (2009).

Daily Costs
Method Amortized Hardware Maint-enance Labor Subscription Cost Total      Cost
Valley and Drake (2007) $84 $23 $1,181  NA  $1,288
Sabol et al. (2009) $84 $23 $250  NA  $357
Hoyer (2009)* $3 $0 $6,881  NA  $6,884
ciBioBase $3 $0 $25 $97 $125
*High resolution vegetationmapping was not an objective of Hoyer (2009) and thus the following scaled-up cost estimates should be viewed as a hypothetical scenario for an equal comparison to other methods

The low rate of ciBioBase doesn’t consider any of the value-added features of ciBioBase such as:

·       Automation: No training needed in hydroacoustics, geostatistics, or GIS.  Our cloud-based software analyzes patterns in the acoustic signal and uses standard geostatistical techniques to produce accurate maps.
·       Centralization: As data from more systems is uploaded, algorithm performance is continually verified and enhanced.  These enhancements are constantly refined in the cloud and are pushed universally to all users, free of charge.

·       Crowd-sourcing: Multiple subscribers from an organization can contribute their data to an optional shared repository.  Organization members can leverage each other’s efforts and data to produce a single output.

·       Speed: Lowrance sonar units occupy little space on board (and actually are portable!) and come with a skimmer transducer that allows data collection of up to speeds of 10 mph.  As such a 500-acre lake may take half the time to traverse 25 mi of transect compared with methods 1 and 2.

·       Efficiency: Because there’s no “set-up and break down” with our method, hitting “record” is the extent of the effort you need to do to start logging data.  While doing so, you can be collecting other important fisheries, aquatic plant, or water quality data on the lake.
·       Data Visualization and Verification: We offer visual, geospatial tools to replay your trip and verify the automated output.

Log in and see for yourself! Go here and type demo@cibiobase.com for the login email and for the password enter “demo.”  You’ll first need Microsoft Silverlight, click here to check to see if you already have it installed on your PC or Mac or need to download it.
Literature Cited
Hoyer, M.V. 2009. Calculations for successful planning. Lakeline Spring 2009: 39-42.

Sabol, B.M., Kannenberg, J., and Skogerboe, J.G. 2009. Integrating acoustic mapping into
              operational aquatic plant management : a case study in Wisconsin. Journal of Aquatic Plant
              Management 44-52.

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.