Gurshin C.W.D.,Normandeau Associates Inc. |
Howell W.H.,University of New Hampshire |
Jech J.M.,National Oceanic and Atmospheric Administration
Fisheries Research | Year: 2013
Repeated acoustic and trawl surveys were performed in the Gulf of Maine cod spawning protection area (GOMCSPA) to: (a) describe the spatial and temporal distribution of spring-spawning Atlantic cod (Gadus orhua); (b) estimate their abundance and biomass; and (c) evaluate precision of the survey methods. A fishing vessel equipped with 38- and 120-kHz split-beam echo sounders surveyed once monthly from dusk to dawn along ten parallel transects that covered a 80.8km2 area during April-July 2011. During each survey, two bottom trawl vessels (one with a small mesh net and one with a large mesh net) each made ten tows in parallel behind the acoustic survey vessel. Cod abundance and biomass was derived from acoustic backscatter by a combination of methods: (1) species apportionment based on trawl catch vs. echo classification; (2) in situ vs. predicted target strength; (3) size of elementary distance sampling unit (EDSU) and statistical approach; and (4) with and without dead zone correction. The mean cod density based on echo classification and a 100-m EDSU resulted in a substantially lower coefficient of variation when the variance was estimated by geostatistics compared to any other method used. Based on echo classification, semivariogram modeling revealed that 67-77% of the variance in cod biomass density was explained by a spatial structural component at a range (correlation length) of 2.0-2.4km. Density maps, produced by ordinary kriging, showed cod were relatively widespread in the survey area in May, but congregated at higher densities in areas adjacent to two elevated bathymetric features. Most cod converged to a single location in June, and were at a higher concentration compared to the highest densities observed in May. This congregation decreased in size and density in July. The survey estimates of cod biomass were 184-494 mt in May, 138-617 mt in June, and 39-135 mt in July. Based on echo classification, the biomass for the GOMCSPA, extrapolated from these survey estimates, were 260-466 mt in May, 196-513 mt in June, and 91-198 mt in July. These results provide some evidence that adult Atlantic cod in spawning condition congregated within the GOMCSPA during the seasonal fishing closure, and that the biomass being protected by the closure may have represented 4-5% of the GOM cod spawning stock biomass at the time of the study. © 2012 Elsevier B.V.
Adams A.M.,Ben - Gurion University of the Negev |
McGuire L.P.,Texas Tech University |
Hooton L.A.,Normandeau Associates Inc |
Brock Fenton M.,University of Western Ontario
Canadian Journal of Zoology | Year: 2015
Passive acoustic monitoring is a common tool used for monitoring bat activity levels. Identifying periods and locations of peak levels provides insight into bat ecology and has important management implications. One limitation of passive acoustic monitoring is the relative nature of the data, often relying on subjective interpretation of descriptive terminology such as “higher” or “lower”. We propose the use of percentile thresholds (PTs) for objectively identifying peak activity. By compiling a reference data set, it is possible to define percentiles of the observed activity levels and these percentiles can provide objective thresholds for comparing activity levels. We used acoustic recordings from sites in Canada and calculated PTs based on the distribution of the number of calls per hour across all nights and sites for three species of bat. Given species ecologies (e.g., hibernating, migrating), we were able to use PTs to objectively identify peak activity levels on a species-specific basis. Percentile thresholds are also a replicable method of describing within-night activity by evaluating species-specific activity patterns and important times of night. Our analyses and examples represent a proof of concept. The next step is to move towards a standardized distribution to generate PTs. Creating a public repository of acoustic data sets to evaluate activity of a species in the context of its entire range would allow us to standardize terms such as “high” activity in an objective manner. © 2015, National Research Council of Canada.All rights reserved.
Stonedahl S.H.,Northwestern University |
Stonedahl S.H.,Davenport University |
Harvey J.W.,U.S. Geological Survey |
Detty J.,U.S. Geological Survey |
And 3 more authors.
Water Resources Research | Year: 2012
Improved predictions of hyporheic exchange based on easily measured physical variables are needed to improve assessment of solute transport and reaction processes in watersheds. Here we compare physically based model predictions for an Indiana stream with stream tracer results interpreted using the Transient Storage Model (TSM). We parameterized the physically based, Multiscale Model (MSM) of stream-groundwater interactions with measured stream planform and discharge, stream velocity, streambed hydraulic conductivity and porosity, and topography of the streambed at distinct spatial scales (i.e., ripple, bar, and reach scales). We predicted hyporheic exchange fluxes and hyporheic residence times using the MSM. A Continuous Time Random Walk (CTRW) model was used to convert the MSM output into predictions of in stream solute transport, which we compared with field observations and TSM parameters obtained by fitting solute transport data. MSM simulations indicated that surface-subsurface exchange through smaller topographic features such as ripples was much faster than exchange through larger topographic features such as bars. However, hyporheic exchange varies nonlinearly with groundwater discharge owing to interactions between flows induced at different topographic scales. MSM simulations showed that groundwater discharge significantly decreased both the volume of water entering the subsurface and the time it spent in the subsurface. The MSM also characterized longer timescales of exchange than were observed by the tracer-injection approach. The tracer data, and corresponding TSM fits, were limited by tracer measurement sensitivity and uncertainty in estimates of background tracer concentrations. Our results indicate that rates and patterns of hyporheic exchange are strongly influenced by a continuum of surface-subsurface hydrologic interactions over a wide range of spatial and temporal scales rather than discrete processes. © 2012. American Geophysical Union. All Rights Reserved.
Trested D.G.,Normandeau Associates Inc |
Chan M.D.,Parsons Brinckerhoff |
Bridges W.C.,Clemson University |
Jeffery Isely J.,U.S. Geological Survey |
Jeffery Isely J.,National Oceanic and Atmospheric Administration
Transactions of the American Fisheries Society | Year: 2011
Long-term restoration efforts for lake sturgeon Acipenser fulvescens populations will benefit from better understanding of this species' movements and habitat use in riverine systems. Radio transmitters were implanted in both juvenile and adult lake sturgeon in the Grasse River, New York, and individuals were relocated over a 2-year period. Adult lake sturgeon demonstrated greater minimum daily distance moved, absolute distance moved, and mean home range size than juvenile lake sturgeon during the spring. During the course of the study, both adult and juvenile lake sturgeon exhibited movements upstream and downstream through a breached low-head weir, and individuals did not necessarily remain resident on an annual basis in the Grasse River. Mesohabitat and substrate use patterns were determined based on comparisons of frequency distributions for relocated lake sturgeon and quantified mesohabitat and substrate over a 15-km river reach. Lake sturgeon used pool mesohabitat and limited their use of runmesohabitat under both low- and mid-flow conditions. During most of the year, adult and juvenile lake sturgeon were detected over silt substrate. This study illustrates behavioral differences and similarities between the movements and habitat use of adult and juvenile lake sturgeon in a riverine system. © American Fisheries Society 2011.
Trested D.G.,Normandeau Associates Inc. |
Isely J.J.,Clemson University
Journal of Applied Ichthyology | Year: 2011
An increased understanding of lake sturgeon (Acipenser fulvescens) population dynamics is a key requirement for successful management efforts. Little is known regarding the Grasse River population of lake sturgeon except that it is one of a few populations in New York State where spawning has been documented. Thus our purpose was to assess the current status of lake sturgeon in the Grasse River system, including age, growth, mortality, and abundance. Age was determined for 196 of 211 lake sturgeon by examination of sectioned pectoral fin rays. Ages ranged from 0 to 32years and the annual mortality rate for fish between ages 7 and 14 was 16.8%. The weight (W, g) to total length (TL, mm) relationship was W=1.281×10-6TL3.202. The von Bertalanffy growth equation was TL=1913(1-e-0.0294(t+9.5691)). While the range of observed ages was similar to that of nearby St. Lawrence River populations, mean weight at age for an individual at 1000mm TL was lower than that observed for lake sturgeon within Lake St. Francis of the St. Lawrence River. Predicted growth based on von Bertalanffy parameters was similar to that observed for the nearby Lake St. Francis. An open population estimator using the POPAN sub-module in the Program MARK produced an abundance estimate of 793 lake sturgeon (95% CI=337-1249). © 2010 Blackwell Verlag, Berlin.
Robinson Willmott J.,Normandeau Associates Inc. |
Forcey G.M.,Normandeau Associates Inc. |
Hooton L.A.,Normandeau Associates Inc.
Ambio | Year: 2015
A scarcity of baseline data is a significant barrier to understanding and mitigating potential impacts of offshore development on birds and bats. Difficult and sometimes unpredictable conditions coupled with high expense make gathering such data a challenge. The Acoustic and Thermographic Offshore Monitoring (ATOM) system combines thermal imaging with acoustic and ultrasound sensors to continuously monitor bird and bat abundance, flight height, direction, and speed. ATOM’s development and potential capabilities are discussed, and illustrated using onshore and offshore test data obtained over 16 months in the eastern USA. Offshore deployment demonstrated birds tending to fly into winds and activity declining sharply in winds >10 km h−1. Passerines showed distinct seasonal changes in flight bearing and flew higher than non-passerines. ATOM data could be used to automatically shut down wind turbines to minimize collision mortality while simultaneously providing information for modeling activity in relation to weather and season. © 2015, The Author(s).
Normandeau Associates Inc. | Date: 2011-10-18
Apparatus for wireless transmission of acoustic information. Consulting in the field of acoustics, sound, noise, and vibration for scientific purposes.
Normandeau Associates Inc. | Date: 2012-07-31
The present invention relates to a system and method for detecting bats from a remote location. In one aspect the invention provides a bat detection system comprising an upper detection unit connected to a base computer unit. The upper detection unit can be positioned on a vertical structure, and a second lower detection unit, or additional detection units, can also be positioned on the vertical structure. Each detection unit comprises a housing which is connected to, and contains, an audio detector. The base computer unit is enclosed by a housing and comprises a data processor, a data storage device, and a remote communication interface device. The data processor is operatively connected to the data storage device, remote communication interface device, and the audio detectors of any detection units positioned on the vertical structure. The base computer unit communicates with a remote computer transferring information regarding the bat sounds detected by the detection units.
PubMed | Normandeau Associates Inc.
Type: | Journal: Ambio | Year: 2015
A scarcity of baseline data is a significant barrier to understanding and mitigating potential impacts of offshore development on birds and bats. Difficult and sometimes unpredictable conditions coupled with high expense make gathering such data a challenge. The Acoustic and Thermographic Offshore Monitoring (ATOM) system combines thermal imaging with acoustic and ultrasound sensors to continuously monitor bird and bat abundance, flight height, direction, and speed. ATOMs development and potential capabilities are discussed, and illustrated using onshore and offshore test data obtained over 16 months in the eastern USA. Offshore deployment demonstrated birds tending to fly into winds and activity declining sharply in winds >10 km h(-1). Passerines showed distinct seasonal changes in flight bearing and flew higher than non-passerines. ATOM data could be used to automatically shut down wind turbines to minimize collision mortality while simultaneously providing information for modeling activity in relation to weather and season.
Normandeau Associates Inc. | Date: 2011-05-06
Mounting Devices for Bat Acoustic Monitoring Equipment.