Dear colleagues,
We are pleased to announce the recent publication of the following
paper on blubber thickness of free-swimming right whales.
The paper is available online and Open Access from:
http://www.int-res.com/articles/meps_oa/m438p267.pdf
Carolyn A. Miller, Desray Reeb, Peter B. Best, Amy R. Knowlton,
Moira W. Brown, Michael J. Moore
Blubber thickness in right whales Eubalaena glacialis and Eubalaena
australis related with reproduction, life history status and
prey abundance
Marine Ecology Progress Series 438:267-283
The high variability in reproductive performance of North
Atlantic right whales Eubalaena glacialis compared to
southern right whales Eubalaena australis may reflect
differences in lipid reserves. Amplitude-mode ultrasound was used
to measure the thickness of right whale integument (epidermis and
blubber, herein referred to as blubber thickness) in E.
glacialis in the Bay of Fundy, Canada for 5 summer seasons
and in E. australis off the South African coast for 2
austral winter seasons. E. glacialis had significantly
thinner blubber layers (mean ±1 SD = 12.23 ± 2.16 cm, n = 172)
than E. australis (16.13 ± 3.88 cm, n = 117), suggesting
differing levels of nutrition between the 2 species. Blubber was
thickest in females measured 3 to 6 mo prior to the start of
pregnancy (E. glacialis), thinner during lactation (E.
glacialis, E. australis) and then thicker with time after
weaning (E. glacialis). These results suggest that lipids
in blubber are used as energetic support for reproduction in
female right whales. Blubber thickness increased in calves during
suckling (E. glacialis, E. australis) but subsequently
decreased after weaning (E. glacialis). Juvenile and adult
male E. glacialis blubber thicknesses were compared
between years of differing prey Calanus finmarchicus
abundances (data from Pershing et al. 2005; ICES J Mar Sci
62:1511–1523); during a year of low prey abundance whales had
significantly thinner blubber than during years of greater prey
abundance. Taken together, these results suggest that blubber
thickness is indicative of right whale energy balance and that the
marked fluctuations in North Atlantic right whale reproduction
have a nutritional component.
Kind regards,
Carolyn A. Miller