Dear Marmam and ECS-listserve subscribers,
Apologies to those of you who will receive duplicate emails due to
cross-posting. 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.
Please do not contact me or the listserve editors for pdfs. Email addresses are
provided for the corresponding authors.
With regards,
Dagmar Fertl
Ziphius EcoServices
http://www.ziphiusecoservices.com
***************************************
Punt, A.E. 2008. A note on the modelling of MSY-related parameters when
population dynamics are stochastic. Journal of Cetacean Research and Management
10(3):183-189.
Contact email: aep...@u.washington.edu
A method is outlined for calculating the values for the parameters which
determine MSYR and MSYL in the types of population dynamics models on which
Implementation Simulation Trials and Evaluation Trials are based in the face of
environmental variability in fecundity (birth rate) and survival. The method is
illustrated using a minke whale-like biology in which MSYR is defined in terms
of
harvesting of the mature female component of the population. Results are shown
for various levels of environmental variation in survival and fecundity.
******************************************************************
Aldrin, M., R. Bang Huseby, and T. Schweder. 2008. A note on tuning the Catch
Limit Algorithm for commercial baleen whaling. Journal of Cetacean Research and
Management 10(3):191-194.
Contact email: magne.ald...@nr.no
The Catch Limit Algorithm for commercial baleen whaling developed by the
International Whaling Commission converges slowly to a steady depletion
(proportion of carrying capacity), and consequently 300 years of management is
proposed as horizon for tuning and computer simulation. Long-term depletion is
rather insensitive to the parameter currently used for tuning, and an
alternative control parameter is suggested for this purpose.
***************************
Rugh, D.J.*, W.R. Koski, J.C. George, and J.E. Zeh. 2008. Interyear
re-identifications of bowhead whales during their spring migration past Point
Barrow, Alaska, 1984-1994. Journal of Cetacean Research and Management
10(3):195–200.
*contact email: dave.r...@noaa.gov
As a part of a review of bowhead whale (Balaena mysticetus) stocks, a study was
conducted to evaluate how much mixing occurs in the whales’ spring migration, a
period which immediately follows the mating season. This study has used aerial
photography of bowhead whales during their spring migration near Point Barrow,
which has resulted in 5,800 images, primarily from 1984 through 1994. These
photographs included 40 different whales seen in at least two years, and of
these, two were seen in three different years, making for a pair-wise sample
size of 42 matches between years. Differences between dates of initial
sightings and subsequent sightings (i.e. resightings) ranged from -31 to +23
days comparing month and day only, irrespective of year. These resightings were
well dispersed across most of the bowhead spring migration; 98% of the
photographs were taken across 45 days from 19 April through 2 June. Models for
predicting resighting date from initial sighting date, whale length, presence
of a calf, year of initial sighting and year of subsequent sightings were
considered, and the best model was chosen using Akaike’s Information Criterion
(AIC). The best model included most predictors but did not include initial
sighting date. Thus, all of the available evidence indicates that individual
mature bowheads do not have a consistent migration timing past Barrow; instead,
in subsequent years they may appear on almost any date within the normal
migratory period. This wide mixing and near-random distribution of resighting
dates throughout the spring migration is indicative of a single stock of whales
that have a somewhat plastic schedule.
**********
Lowry, L.F., K.J. Frost, A. Zerbini, D. DeMaster, and R.R. Reeves. 2008. Trend
in aerial counts of beluga or white whales (Delphinapterus leucas) in Bristol
Bay, Alaska, 1993-2005. Journal of Cetacean Research and Management
10(3):201-207.
Contact email: llo...@hawaii.rr.com
Thirty-eight aerial surveys of beluga or white whales (Delphinapterus leucas)
were conducted in Bristol Bay, Alaska, during six different years between 1993
and 2005. Belugas were sighted mainly close to shore in the upper parts of
Nushagak and Kvichak bays, as well as along the coast between these bays and in
the lower parts of major rivers. Data from 28 complete counts made in good or
excellent survey conditions were analysed for trend. Counts ranged from 264 to
1,067. The estimated rate of increase over the 12-year period was 4.8%/year
(95% CI = 2.1%-7.5%). Such a rate of increase suggests that either the
population was below the environmental carrying capacity in the early 1990s or,
alternatively, that factors that had been limiting population increase were
alleviated after that time. A review of possible changes in human-caused
mortality, predation and prey availability did not reveal a single likely cause
of the increase. Among the factors that could have played a role are recovery
from research kills in the 1960s, a modest decline in subsistence removals and
a delayed response to increases in Pacific salmon (Oncorhynchus spp.) abundance
in the 1980s. The positive growth rate for this population shows that in recent
years there has been no substantial negative impact of human or natural
factors, acting either alone or in combination, and there is no need for
changes to the current management regime.
**************************************************************************************
Afsal, V.V., K.S.S.M. Yousuf, B. Anoop, A.K. Anoop, P. Kannan, M. Rajagopalan,
and E. Vivekanandan. 2008. A note on cetacean distribution in the Indian EEZ
and contiguous seas during 2003-07. Journal of Cetacean Research and Management
10(3):209-215.
Contact email: vaf...@gmail.com
Relatively little is known about the distribution of cetaceans in Indian seas
due to lack of systematic surveys. For collecting data on species distribution,
35 opportunistic surveys were conducted onboard FORV Sagar Sampada between
October 2003 and February 2007 in the Indian EEZ and contiguous seas. In 5,254
hours of sighting effort, a total of 473 cetacean records were made with 5,865
individuals. The
occurrence of 10 species from three cetacean families was confirmed. The
Indo-Pacific bottlenose dolphin was the most frequently sighted species,
whereas the spinner dolphin was dominant in terms of abundance. Long-beaked
common dolphins, Indo-Pacific hump-backed dolphin and sperm whales were also
recorded at frequent intervals. Cetaceans were found to have a wide
geographical distribution in the Indian EEZ and contiguous seas. High abundance
and species richness were recorded in the Southeastern Arabian Sea and southern
Sri Lankan waters. From the information collected during the present study, the
platform of opportunity has proved to be a useful means for cetacean survey.
***************************************************
Palka, D.L.*, M.C. Rossman, A.S. VanAtten, and C.D. Orphanides. 2008. Effect of
pingers on harbour porpoise (Phocoena phocoena) bycatch in the US Northeast
gillnet fishery. Journal of Cetacean Research and Management 10(3):217–226.
Contact email: debra.pa...@noaa.gov
Harbour porpoise (Phocoena phocoena) bycatch in the US Northeast gillnet
fishery is managed under the Harbour Porpoise Take Reduction Plan (HPTRP),
which was implemented on 1 January 1999. The HPTRP divides this fishery into
management areas that are either completely closed to all gillnets or closed
only to gillnets that do not use pingers. Questions about pingers that have
arisen include: (1) would pingers be as effective in an operational fishery as
in controlled scientific experiments; (2) would the fishery comply with these
regulations; and (3) would harbour porpoises habituate to pingers? To
investigate these questions, data from over 25,000 gillnet hauls observed by
the Northeast Fisheries Observer Program after the implementation of the HPTRP,
1999-2007, were examined. In a 1994 controlled scientific experiment conducted
in part of this fishery that used 15cm mesh gillnets, the bycatch rate in
pingered nets was 92% less than that in nets without pingers. In contrast, in
the operational fishery, the bycatch reduction in pingered nets was 50-70%,
depending on the time, area and mesh size. In particular, there was no observed
bycatch in pingered nets that used the same mesh size as used in the
experiment. Thus, it seem that the apparent decrease in pinger effectiveness in
the operational fishery was partially due to the type of gillnet used and lack
of compliance. Pinger usage started out high in 1999 (the first year required),
dropped substantially during 2003-05 and perhaps due to outreach activities
increased beginning in 2006. During years of high pinger usage, 87% of the
tested pingers were functional, while only 36% of the tested pingers were
functional during years of low pinger usage. In general, as expected, observed
bycatch rates in hauls without pingers were greater than bycatch rates in hauls
with the required number of pingers. Unexpectedly, bycatch rates of observed
hauls with an incomplete set of pingers were higher that in observed hauls
without pingers. Confounding factors that could partially explain this
apparently contrary result are discussed. There was no evidence for temporal
trends in the bycatch rates, suggesting that harbour porpoises had not
habituated to the pingers. In conclusion, in the US Northeast gillnet fishery,
harbour porpoises do not appear to have habituated to pingers, and pingers
appear to have reduced the bycatch rate, particularly when the required number
of pingers were used and in nets using mesh sizes of 15cm or less.
**************************************************************************************
Berrow, S., R. Cosgrove, R.H. Leeney, J. O’Brien, D. McGrath, J. Dalgard, and
Y. Le Gall. 2008. Effect of acoustic deterrents on the behaviour of common
dolphins (Delphinus delphis). Journal of Cetacean Research and Management
10(3):227–233.
Contact email: simon.ber...@shannondolphins.ie
Not all delphinids are similarly affected by acoustic deterrent devices
(pingers). At-sea trials were carried out to assess a range of acoustic signals
and deterrents on the behaviour of common dolphins. In initial tests two
acoustic deterrent devices, which previously produced an evasive response by
bottlenose dolphins, failed to elicit any similar behaviour in common dolphins.
A new signal output device, which permitted a range of signals to be tested at
various source levels and characteristics was subsequently developed but again
no significant effects on the behaviour of common dolphins were observed. Two
commercially available acoustic deterrents, which had deterred common dolphins
in previous studies, produced an occasional mild evasive response. Significant
modification of the signal type or source level may be more effective, but our
results suggest that pingers, at their current state of development, may not
provide a consistently effective deterrent signal for common dolphins.
***************************************************************
Trippel, E.A.*, N.L. Holy and T.D. Shepherd. 2008. Barium sulphate modified
fishing gear as a mitigative measure for cetacean incidental mortalities.
Journal of Cetacean Research and Management 10(3):235-246.
Contact email: edward.trip...@dfo-mpo.gc.ca
Incidental mortality from entanglements in fishing gear in threatening cetacean
populations worldwide. In eastern Canadian waters, entanglement deaths of the
critically endangered transboundary North Atlantic right whale (Eubalaena
glacialis) are a key conservation concern and incidental mortalities of harbour
porpoise (Phocoena phocoena) in gillnets are a major source of mortality. Since
the 1990s, a number of mitigation techniques to reduce mortalities in both
species have been tested and the use of some in the US commercial fishery have
been legislated. Despite this, the North Atlantic right whale population
remains in a precarious state and entanglement deaths of harbour porpoise have
been increasing in recent years. Further, mitigation devices, such as acoustic
alarms, carry with them concerns about habituation, noise pollution,
maintenance requirements and cost. The modifying of the physical
characteristics of commercial fishing gear has shown some promise at reducing
entanglement mortalities in initial testing while avoiding many of the
drawbacks of other mitigation methods. In this study the current state of
development and effectiveness of mitigation techniques through the addition of
barium sulphate to fishing gear rope and twine was investigated. The
development of neutrally buoyant groundline, through the addition of barium
sulphate, was undertaken in order to reduce the probability of large whale
entanglement in lobster pot gear. The resulting product maintained a much lower
profile in the water column relative to traditional polypropylene groundline,
however, it was found unsuitable for hard-bottom areas as it was susceptible to
chaffing and breaking. In order to reduce mortalities once large whales are
entangled, a weak rope was developed again with the addition of barium
sulphate. The breaking strength of this product was found to be 1,065 lb, which
meets the US legislated limits (1,100 lb), as opposed to traditional
polypropylene rope which had a breaking strength of over 2,400 lb. To meet the
challenge of harbour porpoise entanglements, a gillnet twine was developed to
have an increased acoustic profile and a more stiff form through the addition
of barium sulphate. In field testing trials, the barium sulphate modified
gillnets reduced harbour porpoise bycatch and the minimal effects on targeted
groundfishes. Although they are in an early state of development, barium
sulphate modified fishing gear shows promise at reducing entanglement deaths of
cetaceans.
***************************************************************
Reeves, R.R.*, T.D. Smith, and E.A. Josephson. 2008. Observations of western
gray whales by ship-based whalers in the 19th century. Journal of Cetacean
Research and Management 10(3):247-256.
Contact email: rrree...@okapis.ca
Animals belonging to the small, endangered population of western gray whales
(Eschrichtius robustus) are observed today primarily during the summer
open-water season in feeding areas off the northeastern coast of Sakhalin
Island, Russia. The migration route(s) and wintering area(s) used by this
population are largely unknown. Gray whales once had a fairly extensive
distribution in the Sea of Okhotsk but little detailed information has been
published on when and where they occurred. Open-boat, ship-based whalers from
the United States and a few other countries conducted an intensive hunt for
bowhead whales (Balaena mysticetus) and North Pacific right whales (Eubalaena
japonica) in the Sea of Okhotsk from the 1840s to 1970s. According to entries
in voyage logbooks, the American whalers regularly encountered (and sometimes
hunted) gray whales in the far northeastern corner of the Okhotsk Sea
(Shelikhov Bay, Gizhiginskaya Bay and Penzhinskaya Gulf) between early May-late
August. They also observed gray whales in summer along the northern coast of
the sea (especially Tauskaya Bay), around the Shantar Islands, in Sakhalin Bay,
off Cape Elizabeth at the northern tip of Sakhalin Island and along the west
coast of the Kamchatka Peninsula. No evidence was found in the logbooks studied
of gray whales (and indeed of whaling effort) off northeastern Sakhalin Island
where most observations of gray whales occur in the present day.
_________________________________________________________________
Windows Live™ SkyDrive™: Store, access, and share your photos. See how.
http://windowslive.com/Online/SkyDrive?ocid=TXT_TAGLM_WL_CS_SD_photos_072009
_______________________________________________
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam
