[MARMAM] Abstracts - latest issue of J Cet Res Mgmt (volume 14, 2014)

Dagmar Fertl dagmar_fertl at hotmail.com
Sun Aug 30 16:39:51 PDT 2015



The following are abstracts from the most recent issue (Volume 14,
issue 1, 2014) of the Journal of Cetacean
Research and Management. 

The International Whaling Commission (IWC) publishes The Journal of Cetacean Research and
Management thrice yearly (Spring, Autumn, and Winter), with at least one
supplement that will contain the full report of the IWC Scientific Committee.
The following is posted on behalf of the IWC and the journal editor. 

Further information can be found at: http://www.iwcoffice.org/publications/JCRM.htm. A guide for authors is included in the
first volume of each issue and on the IWC website: http://www.iwcoffice.org/publications/authorsguide.htm.  

All articles are available as open access at: https://archive.iwc.int/pages/themes.php?theme1=Journal+of+Cetacean+Research+and+Management 

Thank you for your continued interest in the journal and abstract
postings. Please do not queries about the journal or articles to me. 

With regards, 

Dagmar Fertl

*************

Hamilton LJ,
Lindsay K, 2014. Beaked whale strandings on the coast of Australia in
comparison to those of other cetaceans. Journal
of Cetacean Research and Management 14:1-14. 

Beaked whale (Ziphiidae) strandings on the coast of Australia are
examined in comparison to five other odontocete (toothed whale) species and two
mysticetes (baleen whales) representative of non-Ziphiids found stranded in
Australian waters. Ninety percent of reported beaked whale strandings involve a
single animal. Seven beaked whale stranding events of three or more individuals
have been recorded from 1871 to 2010, with a maximum in any event of 6. The
five non-Ziphiid odontocetes had maximum numbers in a stranding of 13, 51, 65,
200, and 250, and a combined total of 66 events with 10+ in a stranding. The
mysticetes had almost exclusively single strandings. Similar trends for the Ziphiids
and other cetaceans are generally observed worldwide, although larger numbers
of Ziphiids have stranded elsewhere. Continental scale geographical stranding
patterns are similar for the Ziphiids, the five non-Ziphiid odontocetes, and
the two mysticetes, although not for the same reasons. Reported strandings
predominantly occurred around the southern half of Australia south of 20°S. On
average around three times as many beaked whale stranding events per month
occurred for the period January to April than for July to December. The monthly
trend for beaked whale strandings follows the seasonal cycle of sea
temperatures, indicating a relation to oceanic phenomena, rather than to the
often invoked effect of increased observer effort in months with warmer air
temperatures. Some single and dual beaked whale strandings which include a
female may be related to use of shallow sheltered waters for calving and
subsequent resting.

************

Morita JG, George
JC, 2014. Age classification of bowhead whales using recursive partitioning. Journal of Cetacean Research and Management
14:15-21. 

An algorithm was derived for using morphometric data to classify bowhead
whales into three age brackets: over 90 years (‘very old’); 60–90 years
(‘old’); and under 60 (‘younger’). Recursive partitioning was applied to a
subset of the data from post mortem examinations. This subset consisted of
whales with higher quality data scores and with either estimated ages or
characteristics of very old animals such as: near-maximum body length and
baleen length; heavy scarring; and ancient weapons embedded in them.
Statistical analysis suggested that for males, body length and peduncle girth
provide the most useful information for this age classification. For females,
anterior flipper length and body length were the key variables for classifying
age. If anterior flipper length is not available for females, then body length,
baleen length and peduncle girth may be used to classify age.

**********

Read AJ, Barco S, Bell J, Borchers DL, Burt ML, Cummings EW, Dunn J,
Meagher Fougeres E, Hazen L, Williams Hodge LE, Laura AM, McAlarney RJ, Nilsson
P, Pabst DA, Paxton CGM, Schneider SZ, Urian KW, Waples DM, McLellan WA, 2014.
Occurrence, distribution and abundance of cetaceans in Onslow Bay, North Carolina,
USA. Journal of Cetacean Research and
Management 14:23-35.

 

In this paper the occurrence, distribution and abundance of cetaceans in
offshore waters of Onslow Bay, North Carolina, USA is described. Between June
2007 and June 2010 monthly aerial and shipboard line-transect surveys were
conducted along ten 74km transects placed perpendicular to the shelf break. In
total 42,676km of aerial trackline (218 sightings) and 5,209km of vessel
trackline (100 sightings) were observed. Seven species of cetaceans were
observed, but the fauna was dominated strongly by common bottlenose and
Atlantic spotted dolphins. Both species were present year-round in the study
area. Using photo identification techniques, five bottlenose dolphins and one
spotted dolphin were resighted during the three-year period. In general, the
abundance of cetaceans in Onslow Bay was low and too few sightings were made to
estimate monthly abundances for species other than bottlenose and spotted
dolphins. Maximum monthly abundances of bottlenose and spotted dolphins were
4,100 (95% CI: 1,300–9,400) in May 2010 and 6,000 (95% CI: 2,500–17,400) in
March 2009, respectively. Bottlenose dolphins were found throughout the study
area, although they were encountered most frequently just off the shelf break.
In contrast, spotted dolphins exhibited a strong preference for waters over the
continental shelf and were not encountered beyond the shelf break.

***********

Bouveroux T, Tyson
RB, Nowacek DP, 2014. Abundance and site fidelity of bottlenose dolphins in
coastal waters near Panama City, Florida. Journal
of Cetacean Research and Management 14:37-42. 

Dolphin watching
and swim-with programmes are popular tourist attractions in Panama City,
Florida, USA. Despite this, little is known about the population of dolphins
that utilise this area, specifically St. Andrew Bay. To learn more about this
population, photo-identification mark-recapture surveys were conducted between
March 2004 and July 2007. The main objectives were to estimate the abundance of
bottlenose dolphins inhabiting this region during this time period and to
examine their patterns of site fidelity. Robust design population models were
used to calculate seasonal abundance estimates, which ranged from 89 (CI 95% =
71–161) to 183 (CI 95% = 169–208) dolphins, even though 263 distinctive
dolphins were identified during the study. Only 7% of dolphins (n = 18)
observed were seen regularly in the study region. In addition, only 12% of
dolphins (n =30) observed had high site fidelity for the study region,
while 58% (n = 153) were considered to be transient to the area. This
study provides baseline information regarding dolphin abundance and site
fidelity in and around St. Andrew Bay that may be used for the conservation and
management of this dolphin population.

*********

Randage SM, Alling
A, Currier K, Heywood E, 2014. Review of the Sri Lanka blue whale (Balaenoptera
musculus) with observations on its distribution in the shipping lane. Journal of Cetacean Research and Management 14:43-49. 

A population of blue whales is resident off the southern coast of Sri
Lanka and has been observed year-round by the crew of a whalewatching vessel, Raja
& the Whales, a few miles south of Mirissa Harbour. Over the course of
three years (1 December 2009 to 30 November 2012), a total of 485 blue whale
sightings were reported with an average of 4.56 individuals observed per
sighting. This number does not represent the total number of individuals seen
because repeat sightings were highly probable. Calves were observed during the
northeast monsoon. Sightings were confined to an area of about 200 n. miles
that is bisected by a heavily trafficked shipping lane. Much of this area is
characterised by submarine canyons and sloping bathymetry, which contributes to
monsoonal seasons of high productivity and upwelling suitable for feeding
whales. While the numbers of injuries and fatalities due to ship strikes are
not known, four dead blue whales were observed along the southern coast over
the course of five months (1 January to 31 May 2014). It is of great urgency to
understand the identity and size of this population, reduce ship strikes and
address all issues threatening this population in order to arrive at possible
mitigation measures for its protection.

***********************

Boye TK, Simon M,
Witting L, 2014. How may an annual removal of humpback whales from
Godthaabsfjord, West Greenland, affect the within-fjord sighting rate? Journal of Cetacean Research and
Management 14:51-56. 

Photo-identifications of humpback whales in the Godthaabsfjord area were
collected from 2007 to 2012 and divided into individuals and number of
sightings per individual. Monte Carlo simulations were performed on the
sighting distributions of individual humpback whales to investigate the
potential impact that local removals (e.g. ship strikes, subsistence hunt)
could have on the sighting rate of humpback whales in Godthaabsfjord. Half of
the sightings were based on the same six individuals during the six year
period. Sighting rate was likely to drop regardless of when (spring, summer or
autumn) an individual was removed due to the large degree of site fidelity of
several humpback whales in Godthaabsfjord. Removals could affect the
whalewatching industry in Godthaabsfjord where humpback whales constitute a key
species. The least impact may be achieved by conducting the hunt outside the
fjord system or minimising summer or autumn hunts within the fjord, as spring
removals tend to have the least effect on summer sighting rates.

*********

Baines ME, Reichelt
M, 2014. Upwellings, canyons and whales: An important winter habitat for
balaenopterid whales off Mauritania, northwest Africa. Journal of Cetacean Research and Management 14:57-67. 

The aim of this study was to identify critical habitats for baleen
whales in the Mauritanian upwelling zone using data collected from a platform
of opportunity: a 60 day geophysical survey approximately 100km southwest of
Cap Blanc, Mauritania in winter (2012/13). The bathymetry of the 5,500km2 study
area was complex, including parts of the Cap Timiris Canyon system. Large
whales, including sei and blue whales, accounted for 70% of the 238 cetacean
sightings. Species identification was often problematic, especially in the case
of balaenopterid whales, so data for all whales of this genus were pooled for
the estimation of abundance and distribution. Spatial modelling was applied to
estimate abundance and to plot a predicted density map of balaenopterid whales.
Depth and the chlorophyll-a concentration when at its peak (in the
previous September) were significant predictors of whale density. Point
abundance in the study area was estimated at 272 whales (95% CI 265–279) and
density was highest in the depth range 500–2,250m near to the canyon system
(6.18 whales/100km2, 95% CI 6.03–6.51). Steep seabed topography created by
canyons running off the shelf edge, together with the strong upwelling system,
probably create optimal habitats for the euphausiid prey of sei and blue
whales. Sei whales were observed skim-feeding at dawn or dusk on seven
occasions; in one sighting an aggregation of 18 skim-feeding sei whales were
observed. The high density of these baleen whale species in such a highly
productive area and direct observation of feeding behaviour in sei whales,
provides evidence of feeding during the winter breeding season, when they have
previously been presumed to feed less. This study demonstrates the potential
value of collecting further data on seismic survey vessels and would improve
understanding of cetacean ecology in remote and under-explored regions.

 

*****************

Greenman JT, McFee WE, 2014. A characterisation of common bottlenose
dolphin (Tursiops truncatus) interactions with the commercial shrimp
trawl fishery of South Carolina, USA. Journal
of Cetacean Research and Management 14:69-79.

 

In the United States, interactions between the shrimp trawl fishery and
bottlenose dolphins are known to exist; however, the level of mortality is
largely unknown, and has not been studied in South Carolina, USA. The current
study attempted to determine if interactions between bottlenose dolphins and
the South Carolina commercial shrimp trawl fishery pose a significant threat to
dolphin populations and if fishery related mortality is underreported. Onboard
observations were made during a 25 day (August–December 2010) field study. No
dolphin takes occurred during the observational period. These observations
focused on direct physical interactions with the gear and depredation
behaviours. Additionally, a subsample of the shrimp fishery in South Carolina
was asked to participate in a mailed survey. The survey included questions
related to gear, dolphin observations, and the status of the shrimp  database for signs of shrimp fishery
interactions. A three-tiered flow diagram was developed to characterise each
stranding case according to the likelihood that mortality resulted from trawler
interaction. Field results point to significant dolphin presence around
commercial trawlers (x2 = 23.406, p < 0.001). Survey results showed
12 unreported incidents of shrimp trawl fishery mortality of dolphins. Finally,
stranding records revealed several more cases with signs of possible trawler
interaction. The current US National Marine Fisheries Service (NOAA)
designation of the fishery as a Category II fishery is correct. Increased
observer coverage and improved communication with the fishery on the importance
of reporting takes is warranted.

 

********************

Punt, AE, 2014. A summary
history of the application of statistical catch-at-age analysis (SCAA) to
Antarctic minke whales. Journal of Cetacean Research and Management 14: 81-92.

 

Various forms of SCAA methods have been applied to data for
Antarctic minke whales since this method was first presented to the Scientific Committee
of the International Whaling Commission by Punt and Polacheck (2005). A brief
overview is provided of the historical use of methods which use catch-at-age
data to draw inferences regarding trends in abundance for Antarctic minke
whales. The original version of the SCAA and how this method has been modified
over time to more adequately mimic the available data on length, conditional
age-at-length and indices of abundance from IDCR/SOWER and JARPA/JARPAII is
described. The paper also lists the specifications for the reference case
analyses in each paper presented to the Scientific Committee. The focus is on
methodology, with only limited comment on the results from each subsequent
analysis.

********************

Punt, AE, Hakamada T, Bando T,
Kitakado T. 2014. Assessment of Antarctic minke whales using statistical
catch-at-age analysis
(SCAA). Journal of Cetacean Research and Management 14: 93-116.

 

Statistical catch-at-age analysis (SCAA) is applied to data
for Antarctic minke whales. The SCAA model is spatially-structured, can model
multiple stocks of minke whales, and can utilise several data types for
parameter estimation. The application to Antarctic minke whales considers two
stocks (I and P) in five areas which cover Antarctic Areas III–E to VI–W. The
parameters of the model (annual deviations about the stock-recruitment relationship,
changes over time in carrying capacity, density-dependence parameters related
to productivity and carrying capacity, and the parameters which determine
growth by stock, age-specific natural mortality by stock, and vulnerability by
area and ‘fleet’) are estimated by fitting the model to data on catches,
catch-at-length, conditional age-at length, and estimates of absolute and
relative abundance. A reference case analysis is selected, and sensitivity
explored using retrospective analyses and by varying the assumptions on which
the reference case analysis is based. The reference case analysis is able to
mimic all of the data sources adequately. Most of the analyses (reference and
sensitivity) indicates that Antarctic minke whales in the assessed area
increased from 1930 until the mid-1970s and have declined thereafter, with the
extent of the decline greater for minke whales in Antarctic Areas III–E to V–W
than for those further east. Natural mortality is consistently estimated to be
higher for younger and older individuals than for individuals of intermediate
age. Estimates of MSYR1+ (the exploitation rate on animals 1 and older at which
sustainable yield is maximised) are presented, but are unreliable owing to the
lack of contrast.

********************

Hampton JO, Mawson
PR, Coughran DK, Vital SD, 2014. Validation of the use of firearms for
euthanising stranded cetaceans. Journal
of Cetacean Research and Management 14:117-123. 

Efforts to euthanise stranded cetaceans remain highly variable in their
outcomes, with few field tested operational procedures available. This study
sought to validate the efficacy of using modern firearms technology to
euthanise small (<6m length) stranded cetaceans. Post-mortem evidence was
gathered from the standardised shooting of cetacean cadavers (n = 10),
representing six species, using .30 caliber (7.62mm) firearms and blunt solid
copper-alloy non-deforming projectiles, in southwestern Australia. The six
species studied were Risso’s dolphin, common dolphin, bottlenosed dolphin,
pygmy sperm whale, Cuvier’s beaked whale, and humpback whale. Post-mortem data
revealed that 100% of bullet wound tracts fully penetrated the skulls of shot
animals, with associated indirect skull fracturing, secondary bone missiles and
brain parenchyma laceration. The results suggest that appropriate firearms
technology is fully capable of inducing instantaneous fatal pathology to the
central nervous system of these species. In comparison to alternative methods
for the euthanasia of stranded cetaceans, the use of firearms is associated
with superior animal welfare outcomes, public safety levels and accessibility.
This paper provides a template for the safe, humane and repeatable use of this
technique to euthanize <6m length stranded cetaceans.

**********

 
Van Der Zee JP,
Punt AE, 2014. Evaluating critical dispersal rates for whale management under
the IWCs Revised Management Procedure: An application for North Atlantic common
minke whales. Journal of Cetacean
Research and Management 14:125-132.



A key consideration for any Revised Management Procedure (RMP) and
Aboriginal Whaling Management Procedure (AMWP) Implementation is the
choice of stock structure hypotheses, and the weighting of alternative stock
structure hypotheses using available data. The RMP/AWMP-lite framework is
applied to the North Atlantic common minke whales for three stock structure
hypotheses and two RMP ‘variants’. The stock structure hypotheses differ in
terms of how many stocks are found in the North Atlantic and how they mix on
the feeding grounds. Focusing on the eastern North Atlantic, simulations are
undertaken to assess when management performance for two RMP variants is
inadequate and how much effective dispersal between adjacent stocks is needed
so that the performance of these variants becomes adequate.

**********

Franklin W,
Franklin T, Gibbs N, Childerhouse S, Garrigue C, Constantine R, Brooks L, Burns
D, Paton D, Poole M, Hauser N, Donoghue M, Russell K, Mattila DK, Robbins J,
Anderson M, Olavarria C, Jackson J, Noad M, Harrison P, Baverstock P, Leaper R,
Baker S, Clapham P, 2014. Photo-identification confirms that humpback whales (Megaptera
novaeangliae) from eastern Australia migrate past New Zealand but indicates
low levels of interchange with breeding grounds of Oceania. Journal of Cetacean Research and Management 14:133-140. 

Recent photo-identification and genetic studies have identified at least
five discrete breeding populations in Australia and Oceania: western Australia
(D), eastern Australia (E (i)), New Caledonia (E (ii)), Tonga (E (iii)), French
Polynesia and the Cook Islands (F). Also evident are low levels of
intermingling among breeding populations consistent with the degree of genetic
differentiation. Photo-identification has confirmed linkages between Area V
feeding areas and eastern Australia breeding grounds and one genotype match has
been reported between Area V feeding areas and Oceania breeding grounds. Recent
abundance estimates show strong increases in the eastern Australian population,
and some recovery in the New Caledonia and Tonga populations, but with little
evidence of recovery at other known Oceania breeding grounds or New Zealand.
Studies to date have provided no conclusive evidence of the migratory
destination of humpback whales passing through New Zealand waters en route between
Antarctic feeding areas and tropical breeding grounds. Photo-identification
comparisons were undertaken between humpback whale fluke catalogues from
eastern Australia (EA, 1315), Oceania east (OE, 513), Oceania west (OW, 166)
and New Zealand (NZ, 13). Five matches were found between OE/OW, four matches
between OW/EA and three matches between NZ/EA. The data are used to investigate
and discuss the migratory destination and breeding ground migratory interchange
of humpback whales travelling through New Zealand waters. The data confirm that
humpback whales with site fidelity to eastern Australia migrate past New
Zealand including through the Cook Strait and Foveaux Strait.

********

Schmitt NT, Double MC, Baker S, Gales N, Childerhouse S, Polanowski AM,
Steel D, Albertson R, Olavarria C, Garrigue C, Poole M, Hauser N, Constantine
R, Paton D, Jenner CS, Jarman SN, Peakall R, 2014. Mixed-stock analysis of
humpback whales (Megaptera novaeangliae) on Antarctic feeding grounds. Journal of Cetacean Research and Management
14:141-157.

 

In understanding the impact of commercial whaling, it is important to
estimate the mixing of low latitude breeding populations on Antarctic feeding
grounds, particularly the endangered humpback whale populations of Oceania.
This paper estimates the degree of genetic differentiation among the putative
populations of Oceania (New Caledonia, Tonga, the Cook Islands and French
Polynesia) and Australia (western Australia and eastern Australia) using ten
microsatellite loci and mtDNA, assesses the power of the data for a mixed-stock
analysis, determines ways to improve statistical power for future studies and
estimates the population composition of Antarctic samples collected in 2010
south of New Zealand and eastern Australia. A large proportion of individuals
could not be assigned to a population of origin (> 52%) using a posterior
probability threshold of > 0.90. The mixed-stock analysis simulations
however, produced accurate results with humpback whales reapportioned to their
population of origin above the 90% threshold for western Australia, New
Caledonia and Oceania grouped using a combined mtDNA and microsatellite
dataset. Removing the Cook Islands, considered a transient region for humpback
whales, from the simulation analysis increased the ability to reapportion Tonga
from 86% to 89% and French Polynesia from 89% to 92%. Breeding ground sample
size was found to be a factor influencing the accuracy of population reapportionment
whereas increasing the mixture or feeding ground sample size improved the
precision of results. The mixed-stock analysis of our Antarctic samples
revealed substantial contributions from both eastern Australia (53.2%, 6.8% SE)
and New Caledonia (43.7%, 5.5% SE) [with Oceania contributing 46.8% (5.9% SE)]
but not western Australia. Despite the need for more samples to improve
estimates of population allocation, our study strengthens the emerging genetic
and non-genetic evidence that Antarctic waters south of New Zealand and eastern
Australia are used by humpback whales from both eastern Australia and the more
vulnerable breeding population of New Caledonia, representing Oceania.



 		 	   		  
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