Seminars

01 Nov 2017
Members of CREEM will present highlights from the Society of Marine Mammal Conference followed by a poster session

Members of CREEM (CREEM)
Seminar Room, The Observatory: 4:00 PM, 01 Nov 2017

Members of CREEM will present highlights from the Society of Marine Mammal Conference (approx 4-5pm) followed by a poster session (approx 5-6pm) with drinks and nibbles.

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08 Nov 2017
Abundance of cetaceans in the European Atlantic: results from SCANS-III aerial and ship surveys in 2016. - Phil Hammond, SMRU

Phil Hammond (SMRU)
Seminar Room, The Observatory: 1:00 PM, 08 Nov 2017

A series of large scale surveys for cetaceans in European Atlantic waters was initiated in 1994 in the North Sea and adjacent waters (project SCANS) and extended in 2005 to all shelf waters south of 62°N (SCANS-II) and in 2007 to offshore waters (project CODA). Objectives were to obtain robust estimates of abundance to place estimates of bycatch and other removals in a population context and to initiate a time series to assess changes in distribution and abundance at an appropriately large spatial scale.  In July/August 2016, the third survey in the series, SCANS-III, was conducted using seven aircraft and three ships, covering an area of approximately 1.8 million km^2 from the Strait of Gibraltar to Vestfjorden, Norway. Data were collected using the circle-back method for aerial and two-team tracker method for ship survey to correct for animals missed on the transect line.  In this talk, I will present design-based abundance estimates for a range of species from harbour porpoise to fin whale and very simple trend and power analysis for harbour porpoise, white-beaked dolphin and minke whale in the North Sea, for which there are three or more comparable estimates of regional abundance. These results have been used to inform assessment of Good Environmental Status (GES) for cetaceans in European Atlantic waters under OSPAR coordination for the EU’s Marine Strategy Framework Directive.

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22 Nov 2017
Mapping blue and fin whale density over large scales using acoustic data. Danielle Harris, CREEM

Danielle Harris (CREEM)
Seminar Room, The Observatory: 2:00 PM, 22 Nov 2017

Using data from passive acoustic monitoring (PAM) to estimate animal density can provide a cost-effective alternative to traditional visual surveys.  One option when designing a PAM survey is to deploy sensors evenly over a large area of interest, thereby maximizing spatial coverage. However, a consequence of this design is that each vocalization cannot be heard across multiple sensors, restricting the choice of density estimation methods.  Density estimation approaches for sparsely distributed sensors have been developed, but may only apply to small ocean areas, and/or require unrealistic assumptions about local animal distribution.  Here, data from the Comprehensive Nuclear Test Ban Treaty Organization International Monitoring System (CTBTO IMS) have been utilized to develop and implement a new method for estimating blue and fin whale density that is effective over large spatial scales and is designed to cope with spatial variation in animal density.  The method requires estimated bearings to calls and a signal to noise ratio (SNR) for each detected call.  Data about sound propagation, call source levels and ambient noise levels, and a detector characterization analysis that estimates the probability of detecting a call as a function of SNR are also required.  Combining this information with spatial modeling, results in an estimated density map around each sensor.  Results from a case study using fin whale detections on CTBTO IMS hydrophones at Wake Island in the Pacific Ocean will be presented. Using data from passive acoustic monitoring (PAM) to estimate animal density can provide a cost-effective alternative to traditional visual surveys.  One option when designing a PAM survey is to deploy sensors evenly over a large area of interest, thereby maximizing spatial coverage. However, a consequence of this design is that each vocalization cannot be heard across multiple sensors, restricting the choice of density estimation methods.  Density estimation approaches for sparsely distributed sensors have been developed, but may only apply to small ocean areas, and/or require unrealistic assumptions about local animal distribution.  Here, data from the Comprehensive Nuclear Test Ban Treaty Organization International Monitoring System (CTBTO IMS) have been utilized to develop and implement a new method for estimating blue and fin whale density that is effective over large spatial scales and is designed to cope with spatial variation in animal density.  The method requires estimated bearings to calls and a signal to noise ratio (SNR) for each detected call.  Data about sound propagation, call source levels and ambient noise levels, and a detector characterization analysis that estimates the probability of detecting a call as a function of SNR are also required.  Combining this information with spatial modeling, results in an estimated density map around each sensor.  Results from a case study using fin whale detections on CTBTO IMS hydrophones at Wake Island in the Pacific Ocean will be presented. 

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23 Nov 2017
Vocal repertoires of two matrilineal social whale species Long-finned Pilot whales (Globicephala melas) & Killer whales (Orcinus orca) in northern Norway

Dr Heike Vester (Ocean Sounds)
LTD, Bute: 1:00 PM, 23 Nov 2017

A vocal repertoire subset from seven groups of pilot whales and 11 groups of killer whales recorded in the Vestfjord in northern Norway during the time period 2004 until 2011 will be presented.

Using observer-based acoustic analysis 129 call types and 25 subtypes for long-finned pilot whales, and 60 call types and 25 subtypes for killer whales were classified. Per group, pilot whales used an average of 36 call types and killer whales 25. The general structure of call types was similar, with most call types consisting of one segment and two elements with different structures. The main element structure in pilot whale and killer whale calls was an ascending frequency band. The amount of two-voiced calls was 29% for pilot whales and 47% for killer whales. In addition, there were different call type combinations and repetitions and ultrasonic whistles, already known in killer whales, but newly described for pilot whales in this study.

The main difference between vocal repertoires of the two species appeared at the call type sharing between the groups. Pilot whales only shared 28% of their call types and 37% of their total calls with at least one other group, whereas killer whales shared 59% of their call types and 90% of their total calls. In 2011 a new foraging method for salmon by killer whales in Norway was discovered and for the first time it was possible to observe the same two groups of killer whales for three and six months and describe a full repertoire with 59 call types and 25 subtypes. It was not possible to completely separate the calling of the two groups, but nevertheless it shows that the vocal repertoire is larger than earlier described. In addition, context-specific vocalisations were detected during salmon feeding and non-feeding contexts, and compared to herring feeding and a food association call from the Icelandic killer whale population. Specifically, certain call type combinations contained the same beginning part in all feeding contexts, but the combinations differed for salmon and herring feeding and between groups. These differences will be discussed in the light of possible referential and/or arousal calling in association with food in killer whales.

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07 Dec 2017
Demographic consequences of individual variation in foraging and migration in seabirds

Francis Daunt (CEH Edinburgh)
LTD, BSRC: 1:00 PM, 07 Dec 2017
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see also: Past Seminars

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