Category: Species domination

Recently Published: Aquatic Plant Dominance and BioBase

We are happy to report the first BioBase-focused paper finally published in the peer-reviewed literature:  “Combining hydroacoustic and point-intercept survey methods to assess aquatic plant species abundance patterns and community dominance.” The paper is co-authored by Navico staff and researchers from Minnesota (Donna Dustin), Florida (Dean Jones), and North Carolina (Justin Nawrocki) and published in the January 2015 issue of the Journal of Aquatic Plant Management.  The paper describes a simple technique for combining aquatic plant species presence/absence information with detailed aquatic plant abundance metrics processed by BioBase [EcoSound] from Lowrance sonar logs to generate detailed information on what aquatic plant species are dominating a mapped lake.  The technique has the potential to greatly advance our understanding of the conditions that cause invasive aquatic plants to “take-over” (a colloquial term for dominate) lakes and provide an objective benchmark from which to evaluate aquatic plant management interventions.

Below is the abstract.  Please contact corresponding author Ray Valley (ray.valley@navico.com) if you are interested in a copy of the paper.

Many ecosystem goods and services are derived from aquatic plant–dominated environments and the abundance and composition of aquatic plant communities affects habitat, recreation, angling, aesthetics, and commerce. We describe standardized hydroacoustic methodology that complements species composition surveys and generates comprehensive aquatic plant abundance data with little additional assessment or analysis effort than is already put forth for species surveys. Using data from 22 lakes across the United States, collected by biologists with varying levels of expertise, we compare hydroacoustically derived biovolume with two other semiquantitative measures of whole-lake abundance (frequency of occurrence and ‘‘rake fullness’’). Although we documented some significant correlations between hydroacoustically derived biovolume and frequency and rake fullness, frequency or rake fullness was difficult to interpret biologically on a lakewide scale. We also describe a dominance index that incorporates both species composition and vegetation biovolume to evaluate the degree that a species dominates a local assemblage. We found that the extent of aquatic plant growth and invasive dominance was related to lake productivity with highest biovolume and dominance occurring in mesotrophic to eutrophic study lakes. Using both empirical and simulated data, we also found no significant differences between dominance calculated from a simple metric that gives equal weight to all species at a survey site and a metric that incorporated rake fullness for each species.

An Unfair War with Aquatic Invasive Species

The Importance of Aquatic Vegetation Abundance Mapping and Long Term Monitoring from a Layman’s Perspective

 

From a layman’s point of view it can be very difficult to understand the importance of lake weeds as they relate to aquatic invasive species (AIS).  I should know . . . I’m a layman.  I started asking questions, and it turns out it’s a bit more complex than I thought.  Sure, I want the Minnesota Lakes I love to be clear with tons of fish, but do we really need these weeds?  Of course we need some “weeds” (“aquatic plants”), and, if you get rid of too many you can throw the entire lake ecology out of balance for years.  When I asked how much is a good amount and how it is being tracked in Minnesota I was disappointed with the answer.  During my time working for the software company Contour Innovations, focusing on automated lake mapping, I’ve had the pleasure of working with some of the most talented aquatic biologists in the Country, both in-house and through our customer base.  I’ve spent the last few years learning the language and attempting to catch on from a neutral, outsider’s perspective.  Slowly, I realized that the complicated topic could be effectively communicated to anyone that cares about and has an interest in water quality . . . which should technically be everyone.

Let’s face it, the DNR has done a great job demonizing invasive species for good reason and with some positive results.  There’s more awareness now and budgets in place to attempt to manage the spread and introduction.  But, eradicating AIS once introduced into a lake is only half the story.  . .
I’ve learned a lot over the last few years but I still had some questions:  Why should our customers really care about the total habitat when Eurasian Water Milfoil has already invaded their lake?  Don’t they just want to know where the Milfoil is so they can get rid of it?  If a monitoring program can’t distinguish between species does it still have a use in aquatic research or management?  I originally thought that identifying where the Milfoil is located is key, but I actually found the opposite to be true.  If we live by the idea that “AIS are bad and should be eliminated at all costs,” wouldn’t the results be easier to obtain? 
The concepts of ecosystem balance are extremely complex but vital.  After early discussions with our biologists it become clear to me that abundance is one of the most important metrics to consider when monitoring water quality and lake health.  This remains true if an invasive species has already been introduced or it’s just knocking on the doorstep.  We need to focus our analysis on total abundance and the overall aquatic habitat instead of speciation as a sole predictor of lake health.  What really matters is knowing if your lake is at risk of the negative impacts from invasive species and if your lake ecology is within certain “healthy” parameters.  A lake’s resilience to invasive species and current water quality regime is going to be a major indicator of lake health and prospects for the future.  It’s also important to quantify your management interventions and determine if they are having their desired effect.  These were difficult questions to answer in the past. 

Invasive species are coming.   We can try to stop it but more likely we’re just delaying it.  The reason these species are thriving is because they’re designed to thrive.  With the right conditions they can easily steal the resources required to grow from other plants, effectively eliminating competition from the lake.  They’re opportunistic and the microscopic amount required for infestation is astonishing.  We should accept this fact and be realistic about what we’re dealing with.  It doesn’t mean we roll over and stop the cleaning stations or citations for failing to drain your bilge, but a proactive management and monitoring plan is a good idea.   

Let’s understand our lake’s resilience and identify if it’s at risk.  Let’s get our resource managers identifying which lakes need close attention and devote our stretched budgets to the ones that need it.  The chips are already stacked against us and without good quantitative data, they’re stacked even further.   With mismanaged resources it becomes a war we can’t win.

At a certain level of productivity, an invasive species will win the war against a diverse ecological aquatic habitat and turn into a lake of a single species.  This isn’t a good thing for any lake ecosystem or water quality.  It’s all about balance and a healthy lake habitat can help keep an infestation in check.  It’s also possible that certain management techniques could push a lake towards a higher risk scenario if decisions were made without quality abundance data.  Understanding the risks of this happening are key in designing a management plan to be proactive instead of reactive.  Identifying hot spots in abundance and potential causes could be more important than identifying where the invasive species exist.  The best thing is that it’s never too early or late to start. 

The entire ecosystem is tied together.   The cumulative effect of lake stressors can lead to the low resilience required for an invasive species to thrive.  Identifying the stressors and dealing with them could prove more valuable than eliminating an invasive species.  Much like a healthy body can deal with the flu virus better than an unhealthy one, a lake with good shorelines, healthy fish communities, and healthy diversity of plant abundance can keep an infestation in check.  In certain conditions, taking plants out of the lake might be a bad decision that could have a negative effect on lake ecology depending on the lake regime and characteristics of the lake.  
In fact, there are ideal targets and optimal or idea habitat levels and conditions.  Our own Ray Valley, a 10 year veteran of the Minnesota DNR, has devoted a majority of his career to habitat monitoring and interactions between plant abundance, fish, lake resilience and relationships to water quality.  His research on ecosystem balance, namely lake resilience, is instrumental in understanding what’s really happening in a lake and when lakes are at risk.  Much of this is actually tied to plant abundance and changes over time.
Through a long term monitoring program it’s possible to identify the red flags.  Plant abundance growing at deeper depths from year to year could show an increase in water clarity allowing more light penetration.  This might be caused by a recent zebra mussel infestation or a shift in the lakes ecology.  Regardless, something as simple as the depth aquatic plants grow tells us a ton about the direction the lake is going.  In another example, unusual increases in plant abundance in specific areas could indicate, among other things, a home with a leaking septic tank on the lake, a change in the landscape, changes in sedimentation, a run-off issue or a bigger problem upstream.  All of these, left unchecked, could cause more problems for the lakes balance and resilience leading to higher risk of negative impacts of an invasive species introduction.   These changes don’t show up in a visual reconnaissance, presence/absence surveys with a rake, or a single map.   But getting these items resolved could be the management technique that keeps an invasive species from dominating a lake habitat in the future and early detection of these problems could prevent an unfair fight against AIS in the future.
Complete dominance of an invasive species is another story but it’s also the exception.  I’ve seen a number of groups continue to dump massive amounts of money into management without quantitative goals or the ability to effectively quantify the whether they are meeting their management expectations.  Maybe we’re not asking the right types of questions or maybe the technology didn’t exist to get the information we need.  No one is at fault yet.  Once the dialog shifts away from hysterical talking points and towards pragmatic management approaches, we’ll start making real strides in getting ahead of AIS and start achieving improvements in our precious lakes.

So where do we start?  With crowd-sourced solutions like ciBioBase.com we can all start getting the volume of data we really need to have this realistic and proactive discussion.  With cloud computing we’ve broadened the base of individuals that can participate allowing passionate home owner groups to take matters into their own hands instead of waiting for an understaffed DNR.   Aquatic plant abundance maps that took a highly trained hydrographer a week or more and to complete can be done by anyone with a boat, a depth finder and GPS, and 20 minutes for computers do the work of processing the collected data.  This is the future of monitoring and lake management.  There are no longer barriers to getting the kind of data we need for identifying the red flags, eliminating stressors and improving lakes across Minnesota and the globe.
So, let’s understand the lakes heartbeat first.  Let’s get a clear picture of the lakes resilience and its current status for optimal health.  Then we move forward to a future with cleaner lakes.

This article represents and aggregation of my thoughts as I’ve journeyed through this industry and tried to learn the ropes.   This is merely an appeal to think differently about our lakes, expectations, and what the future holds.  The future of our most important resource is brightest if we take a step back, think about what we’re doing and where we need to go.
 
Let’s have those realistic and proactive discussions with real data . . .
                                                         -Matt Johnson, CEO, Contour Innovations, LLC

 

CONTOUR INNOVATIONS AND CIBIOBASE

ciBioBase (ciBioBase.com) removes the time and labor required to create aquatic maps! 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!
I’m proud to be a part of this step in the right direction of a positive future for lake management and overall quality of our most precious resource.  We’re shaking things up and this is a time when everyone benefits.  We work as a huge team to define the best uses and features of one of our products, BioBase, to change the lake management industry.  We’re using expert opinions and powerful cloud computing to create amazing contour and vegetation maps and gain important quantitative metrics of lake health.

Our Company has a culture that considers its social responsibility and contribution.  Our sales team is motivated by how they are changing the future of lakes and resources management.  I was most intrigued by what we might be contributing to the future of a resource that means so much to me.  I’m still intrigued!

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!

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