scholarly journals Depredating sperm whales in the Gulf of Alaska: local habitat use and long distance movements across putative population boundaries

2014 ◽  
Vol 24 (2) ◽  
pp. 125-135 ◽  
Author(s):  
JM Straley ◽  
GS Schorr ◽  
AM Thode ◽  
J Calambokidis ◽  
CR Lunsford ◽  
...  
Keyword(s):  
Habitat Use ◽  
Gulf Of Alaska ◽  
Sperm Whales ◽  
Long Distance ◽  
Local Habitat

scholarly journals Acoustic tracking of sperm whales in the Gulf of Alaska using a two-element vertical array and tags

2013 ◽  
Vol 134 (3) ◽  
pp. 2446-2461 ◽  
Author(s):  
Delphine Mathias ◽  
Aaron M. Thode ◽  
Jan Straley ◽  
Russel D. Andrews
Keyword(s):  
Gulf Of Alaska ◽  
Sperm Whales ◽  
Vertical Array ◽  
Acoustic Tracking

Environmental and individual effects on the behaviour and spawning movements of Lethrinus nebulosus on a coral reef

2017 ◽  
Vol 68 (8) ◽  
pp. 1422 ◽  
Author(s):  
R. C. Babcock ◽  
R. D. Pillans ◽  
W. A. Rochester
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Fork Length ◽  
Individual Variability ◽  
Long Distance ◽  
Individual Level ◽  
Use Patterns ◽  
Marine Park ◽  
Seasonal Factors ◽  
Lethrinus Nebulosus

Spatial management of fish populations can potentially be optimised by incorporating responses to environmental variables, such as diel, tidal, lunar and seasonal factors, but individual variability in habitat use and behaviour may complicate such efforts. Acoustic tagging and tracking of 84 Lethrinus nebulosus in the Ningaloo Marine Park indicated that sizes of individual habitat utilisation kernels were similar across diel and tidal cycles, but varied greatly among individuals. Clearly differentiated diel and tidal habitat use patterns were evident in significant proportions of individuals, particularly in relation to tidal phase. For the majority of residents, home-range sizes were reasonably stable over periods of 2–4 years, but in some cases core areas did shift over time. At seasonal time scales, peaks of seasonal activity and home range area were recorded during spawning season (October–December). Long-distance return migrations to spawning locations were observed that were among the longest observed for any reef fish (over 130km). Suspected spawning-related movements were recorded almost exclusively in fish >500-mm fork length, and were semilunar, following quarter moons in October–December. Significant individual-level variability in movement and habitat use patterns, evident across multiple temporal scales, has important implications for the management of L. nebulosus populations.

Acoustic and foraging behavior of tagged sperm whales under natural and depredation foraging conditions in the Gulf of Alaska

2013 ◽  
Vol 134 (5) ◽  
pp. 4008-4008
Author(s):  
Delphine Mathias ◽  
Lauren Wild ◽  
Aaron Thode ◽  
Jan Straley ◽  
John Calambokidis ◽  
...  
Keyword(s):  
Foraging Behavior ◽  
Gulf Of Alaska ◽  
Sperm Whales

From clicks to counts: Applying line-transect methods to passive acoustic monitoring of sperm whales in the Gulf of Alaska

2014 ◽  
Vol 136 (4) ◽  
pp. 2246-2246
Author(s):  
Tina M. Yack ◽  
Thomas F. Norris ◽  
Elizabeth Ferguson ◽  
Brenda K. Rone ◽  
Alexandre N. Zerbini
Keyword(s):  
Gulf Of Alaska ◽  
Acoustic Monitoring ◽  
Line Transect ◽  
Sperm Whales ◽  
Passive Acoustic Monitoring ◽  
Passive Acoustic

scholarly journals Cues, creaks, and decoys: using passive acoustic monitoring as a tool for studying sperm whale depredation

2015 ◽  
Vol 72 (5) ◽  
pp. 1621-1636 ◽  
Author(s):  
Aaron Thode ◽  
Delphine Mathias ◽  
Janice Straley ◽  
Victoria O'Connell ◽  
Linda Behnken ◽  
...  
Keyword(s):  
Low Frequency ◽  
Field Tests ◽  
Sperm Whale ◽  
Acoustic Monitoring ◽  
Sperm Whales ◽  
Passive Acoustic Monitoring ◽  
Long Distance ◽  
Fishing Activity ◽  
Fishing Vessels ◽  
Passive Acoustic

Abstract Since 2003, a collaborative effort (SEASWAP) between fishers, scientists, and managers has researched how Alaskan sperm whales locate demersal longline fishing activity and then depredate sablefish from gear. Sperm whales constantly produce relatively low-frequency biosonar signals whenever foraging; therefore, over the past decade, passive acoustic monitoring (PAM) has become a basic tool, used for both measuring depredation activity and accelerating field tests of potential depredation countermeasures. This paper reviews and summarizes past published PAM research on SEASWAP, and then provides a detailed example of how PAM methods are currently being used to test countermeasures. The review covers two major research thrusts: (i) identifying acoustic outputs of fishing vessels that provide long-distance “cues” that attract whales to fishing activity; and (ii) validating whether distinctive “creak” sounds can be used to quantify and measure depredation rates, using both bioacoustic tags and statistical comparisons between visual and acoustic depredation estimates during federal sablefish surveys. The latter part of the paper then provides an example of how PAM is being used to study a particular potential countermeasure: an “acoustic decoy” which transmits fishing vessel acoustic cues to attract animals away from true fishing activity. The results of an initial 2011 field trial are presented to show how PAM was used to design the decoy signals and monitor the efficacy of the deployment. The ability of PAM to detect both whale presence and depredation behaviour has reduced the need to deploy researchers or other specialists on fishing cruises. Instead, volunteer fishers can deploy “user-friendly” acoustic recorders on their gear, greatly facilitating the testing of various deterrents, and providing the industry and regulators a convenient and unobtrusive tool for monitoring both the scale and long-term spread of this behaviour across the Alaskan fishery.

Habitat use and behaviour of Greater Snow Geese during movements from nesting to brood-rearing areas

2006 ◽  
Vol 84 (8) ◽  
pp. 1096-1103 ◽  
Author(s):  
J. Mainguy ◽  
G. Gauthier ◽  
J.-F. Giroux ◽  
I. Duclos
Keyword(s):  
Habitat Use ◽  
Long Distance ◽  
High Quality ◽  
Chen Caerulescens ◽  
Brood Rearing ◽  
Snow Geese ◽  
Greater Snow Goose ◽  
Chen Caerulescens Atlantica ◽  
Precocial Birds ◽  
Aerial Tracking

Many precocial birds make long-distance movements with their young after hatch to reach the best foraging sites. On Bylot Island, Nunavut, a large number of Greater Snow Goose ( Chen caerulescens atlantica L., 1758) families move 30 km from the main nesting colony (MNC) to reach the main brood-rearing area (MBR) soon after hatch. Geese moving from the MNC to the MBR generally rear lighter and smaller goslings than geese that avoid this movement by both nesting and rearing their brood at the MBR. In this study, we tested the hypotheses that use of low-quality habitats and an increase in the time spent walking at the expense of foraging during movements could explain the reduced growth of goslings in those families. We conducted visual observations to compare habitat use and selection as well as behaviour of geese during brood movements from the MNC to the MBR (i.e., at a transit area) with those of families that had already settled at the MBR. We also conducted aerial tracking to monitor habitat use of 16 radio-marked females during and after brood movements. Streams, wet polygons, and lakes, considered high-quality habitats in terms of feeding opportunities and predator refuges, were preferred, while upland, a low-quality habitat, was avoided at both the transit area and the MBR. However, broods were found in the upland habitat more often during movements than once settled on a rearing site. The behaviour of unmarked geese at the transit site did not differ from that of geese at the MBR. We suggest that reduced food intake in low-quality habitats during movements, but not the increase in time spent walking, may explain the reduction in growth observed at fledging in goslings moving from the MNC to the MBR.

Local habitat use by botos (Amazon river dolphins,Inia geoffrensis) using passive acoustic methods

2015 ◽  
Vol 32 (1) ◽  
pp. 220-240 ◽  
Author(s):  
Yukiko Yamamoto ◽  
Tomonari Akamatsu ◽  
Vera M. F. da Silva ◽  
Shiro Kohshima
Keyword(s):  
Habitat Use ◽  
Amazon River ◽  
Acoustic Methods ◽  
Inia Geoffrensis ◽  
Passive Acoustic ◽  
Local Habitat

scholarly journals Southeast Alaska Sperm Whale Avoidance Project (SEASWAP): a successful collaboration among scientists and industry to study depredation in Alaskan waters

2015 ◽  
Vol 72 (5) ◽  
pp. 1598-1609 ◽  
Author(s):  
Janice Straley ◽  
Victoria O'Connell ◽  
Joe Liddle ◽  
Aaron Thode ◽  
Lauren Wild ◽  
...  
Keyword(s):  
Sperm Whale ◽  
Gulf Of Alaska ◽  
Global Studies ◽  
Sperm Whales ◽  
Catch Per Unit Effort ◽  
Southeast Alaska ◽  
Vessel Area ◽  
Stock Assessments ◽  
Presence And Absence ◽  
Successful Collaboration

Abstract In Alaskan waters, depredation on sablefish longline gear by sperm whales increases harvesting cost, negatively biases stock assessments, and presents a risk of entanglement for whales. The Southeast Alaska Sperm Whale Avoidance Project (SEASWAP), a collaborative effort involving industry, scientists, and managers, since 2003 has undertaken research to evaluate depredation with a goal of recommending measures to reduce interactions. Prior to 2003, little was known about sperm whale distribution and behaviour in the Gulf of Alaska (GOA). Although fishers were reporting increasing interactions, the level of depredation varied with no apparent predictor of occurrence across vessels. Between 2003 and 2007, fishers were provided with fishery logbooks and recorded information on whale behaviour, whale presence and absence, during the set, soak, and haul for 319 sets in the GOA. Data were evaluated for a vessel, area, and seasonal (month) effect in the presence and absence of sperm whales. Using catch per unit effort (cpue) as a metric, in kg/100 hooks, results indicated that depredation depended on both the vessel and the area. More whales associated with vessels from April to August. Sperm whales were also likely to be present when cpue was high, revealing that whales and fishers both knew the most productive fishing areas, but confounding the use of cpue as a metric for depredation. Using a Bayesian mark-recapture analysis and the sightings histories of photo-identified whales, an estimated Nˆ=135 (95% CI 124, 153) sperm whales were associating with vessels in 2014. A spatial model was fitted to 319 longline sets and quantified a 3% loss in cpue, comparable to other global studies on sperm whale depredation. Through all phases of SEASWAP, our understanding of depredation has gained significantly. This successful collaboration should be considered as a model to create partnerships and build collaborations between researchers and fisherpeople encountering marine mammal interactions with fishing gear.

scholarly journals Correcting Positional Errors in Shore-Based Theodolite Measurements of Animals at Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ophélie Sagnol ◽  
Femke Reitsma ◽  
Christoph Richter ◽  
Laurence H. Field
Keyword(s):  
New Zealand ◽  
Habitat Use ◽  
Marine Mammal ◽  
Positional Information ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Vertical Angle ◽  
Position Accuracy ◽  
Wide Range ◽  
The Difference

Determining the position of animals at sea can be particularly difficult and yet, accurate range and position of animals at sea are essential to answer a wide range of biological questions. Shore-based theodolite techniques have been used in a number of studies to examine marine mammal movement patterns and habitat use, offering reliable position measurements. In this study we explored the accuracy of theodolite measurements by comparing positional information of the same objects using two independent techniques: a shore-based theodolite station and an onboard GPS over a range of 25 km from the shore-based station. The technique was developed to study the habitat use of sperm whales (Physeter macrocephalus) off Kaikoura, New Zealand. We observed that the position accuracy fell rapidly with an increase in range from the shore-based station. Results showed that the horizontal angle was accurately determined, but this was not the case for the vertical angle. We calibrated the position of objects at sea with a regression-based correction to fit the difference in distance between simultaneously recorded theodolite fixes and GPS positions. This approach revealed the necessity to calibrate theodolite measurements with objects at sea of known position.

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