Environmental and Aquatic Resource Consulting

By: Milne Technologies  09-12-2011
Keywords: Fish, modeling, Hydroacoustics

Hydroacoustics

Stock Assessment and Resource Monitoring
Hydroacoustic technology has been proven an effective method for estimating fish abundance and biomass in lakes, rivers, and oceans. Using hydroacoustic technology, large volumes of water can be sampled within a relatively short period of time. This technology, when integrated with other fish sampling methods, provides a size and/or species specific estimate of fish abundance with high confidence and precision.

Survey Design and Methodology
Careful consideration and planning of survey design and methodology is crucial when providing meaningful information about the population abundance, behaviour, or spatial distribution of aquatic organisms. When designing hydroacoustic surveys, the user should consider a number of questions: What frequency should I use?  Should I complete a daytime or nighttime survey?  Where do I place my transect lines?  How long should my transects be?  These are just a few of the questions we can help you answer before you get on the water to ensure that the data you collect is meaningful and accurate.  These are just a few of the questions that Milne Technologies can help you answer before you get on the water, thus ensuring that the data you collect is meaningful and accurate. To help you effectively design your survey, important considerations include the geographic extent and spatial distribution of the population, the horizontal and vertical movements of the focal species, behavioral characteristics such as schooling and spawning, and available vessel time and budget.

Habitat, Bathymetric, and Submerged Macrophyte Mapping

Behavioural Ecology
Hydroacoustics can be used to study the in situ behaviour of fish and zooplankton. This can provide a rare glimpse into predator-prey spatial dynamics and behavioural responses, foraging and social interactions, and the collective behaviour of individuals in fish schools. In addition, hydroacoustics can provide data on the movement of individuals and schools in three dimensions, vertical and horizontal swimming speed, gear avoidance, school size and shape characteristics, and encounter rates of predators with their prey.

Multivariate Statistical Analyses of Fisheries Data
Fish, invertebrate, and aquatic plant populations are influenced by a variety of environmental factors in a suite of complex ways. Multivariate statistics are needed to analyze data of this nature and reveal patterns of association between, for example, fish abundance and habitat characteristics.

Other Services Provided Incude:

  • stock assessment modeling
  • fish aging and growth methodology
  • fish and invertebrate population sampling
  • water chemistry and physical limnology
  • statistical analyses of time series data
  • evolutionary modeling
  • multi-species food web modeling using Ecopath with Ecosim
  • scientific writing of journal articles for publication
  • side-scan habitat mapping
  • GIS analysis

Keywords: Fish, Hydroacoustics, modeling, stock assessment,