Fisheries Scientist Jim Lyons from the UK’s Environment Agency has been in action over the last few months introducing Yorkshire Fisheries Officers to the benefits of the BioBase system. Following two days of survey work on a couple of gravel pit fisheries in the area the team received a report less than a week later. Mike Lee from the local team and the angling clubs who manage the waters, were very impressed with the technique and the report generated. They have come away with a host of ideas about how to further use Lowrance Fish Finders and the Biobase System across their catchment in both river and Stillwater fisheries.
Further Mr. Lyons, recently presented to aquatic plant specialists from the Environment Agency, Natural England and Natural Resources Wales at Preston Montford Field Studies centre as part of the relaunch of the aquatic plant specialist’s network.
Area specialist are responsible for the technical lead for aquatic plant survey delivery within their Area, ensuring that all aquatic plant surveyors are suitably trained and have the relevant support to deliver their surveys. The specialists also play a key role in underpinning the delivery of the quality assurance programme.
Mr. Lyons talked about ‘Using acoustics and cloud-based technology to monitor aquatic weed.’He shared with the group the benefits of using BioBase to inform weed management programmes. Enthusiastic feedback from the group has provided a number of potential new applications for this technology from across the Department of Environment, Food, and Rural Affairs (DEFRA) family organisations present.
We are grateful to the aquatic research community who continue to verify and validate Consumer Sonar Technologies (Lowrance) and BioBase automated mapping platform to produce scientifically valid outputs that benefit aquatic conservation. We are excited to see the recent publication of research out of the University of New Brunswick that evaluated the accuracy and precision of Lowrance and BioBase’s EcoSound depth and vegetation outputs. The research is published in the open access journal Diversity and can be downloaded here. Below is the abstract
The development of consumer hydroacoustic systems continues to advance, enabling the use of low-cost methods for professional mapping purposes. Information describing habitat characteristics produced with a combination of low-cost commercial echosounder (Lowrance HDS) and a cloud-based automated data processing tool (BioBase EcoSound) was tested. The combination frequently underestimated water depth, with a mean absolute error of 0.17 ± 0.13 m (avg ± 1SD). The average EcoSound bottom hardness value was high (0.37–0.5) for all the substrate types found in the study area and could not be used to differentiate between the substrate size classes that varied from silt to bedrock. Overall, the bottom hardness value is not informative in an alluvial river bed setting where the majority of the substrate is composed of hard sands, gravels, and stones. EcoSound separated vegetation presence/absence with 85–100% accuracy and assigned vegetation height (EcoSound biovolume) correctly in 55% of instances but often overestimated it in other instances. It was most accurate when the vegetation canopy was ≤25% or >75% of the water column. Overall, as a low-cost, easy-to-use application EcoSound offers rapid data collection and allows users with no specialized skill requirements to make more detailed bathymetry and vegetation maps than those typically available for many rivers, lakes, and estuaries.
The centralized nature of BioBase (biobasemaps.com) cloud technologies coupled with sophisticated, yet low-cost consumer electronics like Lowrance or Simrad depth sounders/chartplotters have created fertile grounds for developing, testing, and verifying algorithms for typing aquatic environments. The more users upload from a greater range of systems, the more refined algorithms can become addressing a wider range of conditions and use cases!
Early in 2014, we released a revision to our EcoSound bottom composition (hardness) algorithm that is more sensitive and robust in a greater range of depths and bottom conditions. Many outside researchers were involved with collecting important “ground truth” information while they logged their BioBase data. This blog not only serves to describe the new Bottom Composition algorithm, but also publish the results and acknowledge the scientists that helped with this effort.
I frequently get inquiries from current and prospective BioBase users about the accuracy of consumer-grade Lowrance GPS and whether survey-grade 3rd party receivers capable of differential correction (DGPS) or receiving positions from multiple satellite constellations (Global Navigation Satellite System – GNSS) could be used with Lowrance and processed with BioBase.
The first question about accuracy prompted a test in March of 2013 with a Lowrance HDS tested side-by-side with a Trimble GeoXH. I was pleased to find less than 1m deviation on average from post-processed Trimble DGPS positions. One meter accuracy and precision is typically sufficient for most boat-based mapping applications. Still, prerequisites for some projects require DGPS, and there are a number of BioBase users who have and still would prefer to have DGPS generated positions to use when logging trips. Thus, I was interested in exploring the capabilities of networking positions from a third-party receiver into a Lowrance HDS.
River channel thalwegs (the line of lowest elevation within a valley or watercourse) are often dynamic, and sometimes hidden features of large river systems. Especially low slope or impounded systems. The thalweg is a critical geomorphological feature of river and reservoir systems and affects everything from sediment transport, to fisheries habitat, to algae or invasive plant control.
Thus a good bathymetric contour map is a necessary pre-requisite for effective river and reservoir management. Here, we walk you through how to use new real time technologies (C-MAP’s Genesis Live) to produce smooth, precise, and accurate maps of hidden river thalwegs all within one trip to the site and with automated post-processing with BioBase’s EcoSound. We’ll use an annotated image gallery to take you through this process.
North Carolina State University; Dept. Crop and Soil Sciences
Why do we want to sample submersed vegetation biomass using sonar?
Invasive aquatic plants, such as non-native hydrilla (Hydrilla verticillata), negatively impact waterway systems in the southeastern United States and on a global scale. Often, these aquatic weed species impede recreational activities, power generation, and disrupt native ecological systems. Costs associated with aquatic weed management include expenses accompanied with monitoring, mapping, and implementing control measures. Prompt detection and accurate mapping of submersed aquatic vegetation (SAV) are critical components when formulating management decisions and practices. Therefore, SAV management protocols are often reliant upon the perceived extent of invasion. Traditional biomass sampling techniques have been widely utilized, but often require significant labor inputs, which limits repeatability, the scale of sampling, and the rapidness of processing. Advances in consumer available hydroacoustic technology (sonar) and data post-processing offer the opportunity to estimate SAV biomass at scale with reduced labor and economic requirements.
The objectives of this research were to document the use of an off-the-shelf consumer sonar/gps chartplotter to: 1) describe and characterize a relationship between hydroacoustic biovolume signature to measured hydrilla biomass; 2) develop algorithm for on-the-fly assessment of hydrilla biomass from interpolated biovolume records; 3) define seasonal hydrilla growth patterns at two NC piedmont reservoirs; and 4) create a visual representation of SAV development over time. From these objectives, the expected outcome was to describe a protocol for passive data collection while reducing the economic inputs associated with labor efforts involved in biomass sampling and post-processing evaluations. In our research, a Lowrance HDS-7 Gen2 was utilized to correlate biomass from monospecific stands of hydrilla within two different North Carolina piedmont reservoirs using BioBase 5.2 (now marketed as EcoSound – http://www.biobasemaps.com), cloud-based algorithm to aid in post-processing.
BioBase’s EcoSound bottom composition (hardness) algorithm has become quite popular for researchers and lake/pond managers to determine where sedimentation from the watershed may be occurring. However, interpreting sonar returns in shallow environments (e.g., less than 7 ft or 2 m) with off-the-shelf sonar is challenging, especially if aquatic vegetation is present. Each situation is different and the objective of this blog is to inform you of how to interpret your EcoSound map in situations when you encounter counter intuitive bottom hardness results.
Thanks to advances in physical, chemical and biological technologies and funding that are focused on reducing sedimentation or muck depth in waterways, many water resource practitioners are eager to determine how much sediment is in a waterway of interest and how much could be removed. As such, we frequently are asked: “Will BioBase tell you how deep the sediment is?”
Although BioBase EcoSound was originally developed for aquatic vegetation mapping in inland lakes, users along both US Coasts have helped us diversify its toolbox to now be a powerful coastal habitat mapping tool as well!
One of the biggest challenges of mapping coastal habitats is their tidal influence with depths changing harmonically based on the moon phase and other factors. Fortunately, however, widespread tide stations and large public databases of tide predictions allow for accurate and precise offsets to georeferenced and time-stamped sonar logs from Lowrance HDS or Elite units uploaded to BioBase EcoSound. BioBase EcoSound immediately queries the nearest tide station to your upload (up to 75 km) and adjusts your depth and seagrass or kelp biovolume to the Mean Lower Low Water (MLLW) datum every 5 minutes. Tidal statistics (Avg., start, stop, high, low,) are archived in your account for each trip.
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.