FN Archimer Export Format
PT J
TI Declining reproductive success in the Gulf of St. Lawrence’s humpback whales (Megaptera novaeangliae) reflects ecosystem shifts on their feeding grounds
BT 
AF Kershaw, Joanna L.
   Ramp, Christian A.
   Sears, Richard
   Plourde, Stéphane
   Brosset, Pablo
   Miller, Patrick J. O.
   Hall, Ailsa J.
AS 1:1,2;2:1,2;3:2;4:3;5:3,4,5;6:1;7:1;
FF 1:;2:;3:;4:;5:;6:;7:;
C1 Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews, UK
   Mingan Island Cetacean Study Saint Lambert QC ,Canada
   Department of Fisheries and Oceans Canada Maurice Lamontagne Institute Mont‐Joli QC ,Canada
   Laboratoire de Biologie Halieutique Ifremer Plouzané ,France
   Laboratoire des Sciences de l'Environnement Marin ‐ IUEM Université de Brest ‐ UMR 6539 CNRS/UBO/IRD/Ifremer Plouzané,France
C2 UNIV ST ANDREWS, UK
   MINGAN ISLAND CETACEAN STUDY, CANADA
   MPO INST MAURICE LAMONTAGNE, CANADA
   IFREMER, FRANCE
   UBO, FRANCE
SI BREST
SE PDG-RBE-STH-LBH
UM LEMAR
IN WOS Ifremer UPR
   WOS Cotutelle UMR
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
IF 13.212
TC 26
UR https://archimer.ifremer.fr/doc/00665/77758/93563.pdf
LA English
DT Article
DE ;biopsy;calving rates;endocrine profiling;environmental change;marine mammals;photo-identification;pregnancy rates
AB Climate change has resulted in physical and biological changes in the world's oceans. How the effects of these changes are buffered by top predator populations, and therefore how much plasticity lies at the highest trophic levels, are largely unknown. Here endocrine profiling, longitudinal observations of known individuals over 15 years between 2004 and 2018, and environmental data are combined to examine how the reproductive success of a top marine predator is being affected by ecosystem change. The Gulf of St. Lawrence, Canada, is a major summer feeding ground for humpback whales (Megaptera novaeangliae) in the North Atlantic. Blubber biopsy samples (n = 185) of female humpback whales were used to investigate variation in pregnancy rates through the quantification of progesterone. Annual pregnancy rates showed considerable variability, with no overall change detected over the study. However, a total of 457 photo‐identified adult female sightings records with/without calves were collated, and showed that annual calving rates declined significantly. The probability of observing cow–calf pairs was related to favourable environmental conditions in the previous year; measured by herring spawning stock biomass, Calanus spp. abundance, overall copepod abundance and phytoplankton bloom magnitude. Approximately 39% of identified pregnancies were unsuccessful over the 15 years, and the average annual pregnancy rate was higher than the average annual calving rate at ~37% and ~23% respectively. Together, these data suggest that the declines in reproductive success could be, at least in part, the result of females being unable to accumulate the energy reserves necessary to maintain pregnancy and/or meet the energetic demands of lactation in years of poorer prey availability rather than solely an inability to become pregnant. The decline in calving rates over a period of major environmental variability may suggest that this population has limited resilience to such ecosystem change. 
PY 2021
PD MAR
SO Global Change Biology
SN 1354-1013
PU Wiley
VL 27
IS 5
UT 000601403400001
BP 1027
EP 1041
DI 10.1111/gcb.15466
ID 77758
ER

EF