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”

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.

Guest Blog: ciBioBase and Arctic charr habitat in Windermere, U.K.

By Dr. Ian J. Winfield and Joey van Rijn

The Arctic charr (Salvelinus alpinus) is well appreciated as an important fisheries species in many northern areas of the world.  In addition, it is equally important to evolutionary biologists because of this species’ frequent development of ‘morphs’ or ‘types’ and their bearing on our understanding of mechanisms of speciation (Figure 1).  In the U.K., this fascinating fish is also recognised as having great nature conservation value.

Figure 1.  A female (top) and male (bottom) Arctic charr from Windermere, U.K.  Photo courtesy of the Center for Ecology and Hydrology)

Windermere is England’s largest lake and has been at the forefront of several areas of Arctic charr research for many decades, with the notable exception of studies of their spawning grounds (Figure 2).  Despite their long appreciated significance for the coexistence of autumn- and spring-spawning Arctic charr types, local spawning grounds have not been studied in any detail since their original brief description in the 1960s.  At that time, laborious and spatially-limited direct observations by divers showed that spawning requires the availability of gravel or other hard bottom habitat.  New information on these critical areas is needed by ecologists and evolutionary biologists and, more urgently, by fisheries and conservation organisations responsible for the management of Windermere.

Figure 2.  Breathtaking view of Windermere’s north basin; home to several spawning populations of Arctic charr.  Photo courtesy of Dr. Ian Winfield.

We are currently using the newly developed bottom hardness capability of ciBioBase to survey and characterise the spawning grounds of Arctic charr in Windermere.  Limited underwater video is being used for ground-truthing, but the combination of a Lowrance HDS-5 sounder with ciBioBase is allowing us to investigate the known spawning grounds with unprecedented speed (Figure 3).  For the first time, we have been able to document in detail the bathymetry and bottom features of a long-monitored (for spawning fish) spawning ground just north of the island of North Thompson Holme in the lake’s north basin.  ciBioBase is also enabling us to examine other known spawning grounds in Windermere and to expand our coverage to other potential areas previously unstudied.

Figure 3. An example ciBioBase output of bottom composition on and around the Arctic charr spawning ground of North Thompson Holme in the north basin of Windermere

The rapidity of the field component of hydroacoustic surveys is well known.  ciBioBase now offers us a similarly fast method of hydroacoustic data analysis for key environmental characteristics in relation to the spawning of Arctic charr.  This new approach helps us to dramatically increase our return on investment and also allows us to review results within hours of coming off the water, leading in some cases to us adapting our field plans on the basis of initial results.

Dr. Ian J Winfield is a Freshwater Ecologist at the Centre for Ecology & Hydrology in Lancaster, U.K.  He has over 30 years of research experience in fish and fisheries ecology, hydroacoustics, and lake ecosystem assessment and management.  Dr. Winfield sits on several regional, national and international advisory boards and is the current President of the Fisheries Society of the British Isles (FSBI).

Joey van Rijn is an undergraduate student currently following a BSc. degree course in Applied Biology at the University of Applied sciences, HAS Den Bosch, in the Netherlands. He is experienced in ecological and particularly phenological research including work on temperature-induced differences between urban and rural areas in the timing of blossoming and leaf unfolding in shrubs.  He has also been involved with the development of fish ways for standing waters in the Netherlands. Joey is currently undertaking a research internship at the Centre for Ecology & Hydrology in Lancaster, U.K., where his research mainly focuses on using hydroacoustics to investigate Arctic charr spawning grounds in Windermere.