Potential impacts of low‐frequency anthropogenic noise on the hearing of subarctic beluga whales in the Saint Lawrence estuary

1997 ◽  
Vol 101 (5) ◽  
pp. 3164-3164
Author(s):  
Peter M. Scheifele
2016 ◽  
Vol 74 (4) ◽  
pp. 1230-1236 ◽  
Author(s):  
Danielle A. Poulton ◽  
Cosima S. Porteus ◽  
Stephen D. Simpson

Ocean acidification (OA) and anthropogenic noise are both known to cause stress and induce physiological and behavioural changes in fish, with consequences for fitness. OA is also predicted to reduce the ocean's capacity to absorb low-frequency sounds produced by human activity. Consequently, anthropogenic noise could propagate further under an increasingly acidic ocean. For the first time, this study investigated the independent and combined impacts of elevated carbon dioxide (CO2) and anthropogenic noise on the behaviour of a marine fish, the European sea bass (Dicentrarchus labrax). In a fully factorial experiment crossing two CO2 levels (current day and elevated) with two noise conditions (ambient and pile driving), D. labrax were exposed to four CO2/noise treatment combinations: 400 µatm/ambient, 1000 µatm/ambient, 400 µatm/pile-driving, and 1000 µatm/pile-driving. Pile-driving noise increased ventilation rate (indicating stress) compared with ambient noise conditions. Elevated CO2 did not alter the ventilation rate response to noise. Furthermore, there was no interaction effect between elevated CO2 and pile-driving noise, suggesting that OA is unlikely to influence startle or ventilatory responses of fish to anthropogenic noise. However, effective management of anthropogenic noise could reduce fish stress, which may improve resilience to future stressors.


1979 ◽  
Vol 36 (11) ◽  
pp. 1325-1335 ◽  
Author(s):  
L. Fortier ◽  
L. Legendre

Hourly series of summer phytoplankton biomass (ATP and chlorophyll a) and photosynthetic capacity (14C assimilation and ATP increase in saturating light) were sampled in the lower St. Lawrence Estuary during the summer of 1977. Vertical stability of the water column was estimated by the Richardson number. From the results it is concluded that the mean level of biomass is an inverse function of critical depth, likely linked to the neap-spring tidal cycle (Mf). On the other hand, the fine fluctuations of biomass and photosynthetic activity were related to vertical stability, which varies according to the semi-diurnal tidal cycle (M2). A simple model was developed on the basis of Sverdrup's critical depth, combining the M2 fluctuations in stability (degree of vertical mixing) to Mf variations in critical depth. Net biomass increases, observed in a nonturbid stabilized water column, cannot be explained by the growth rates computed from 14C assimilation, but they are consistent with the measured rates of ATP production. Spectral analyses of time series of temperature and Richardson number suggest that low frequency water column stability variations amplify the spatial heterogeneity of a reacting parameter such as phytoplankton. On the other hand, a passive scalar such as temperature does not respond to these low frequency variations of stability. It follows that the study of stability spectra may give some insight into the low frequency control of phytoplankton dynamics. Key words: phytoplankton, St. Lawrence Estuary, variability, vertical stability, critical depth, Richardson number, Kendall's cross correlation, spectral analysis


1994 ◽  
Vol 31 (4) ◽  
pp. 444-449 ◽  
Author(s):  
S. De Guise ◽  
A. Lagacé ◽  
P. Béland

A population of 450–500 belugas ( Delphinapterus leucas) resides in the polluted estuary of the St. Lawrence River. Stranded carcasses of this endangered population were recovered and necropsied. High concentrations of organochlorines, heavy metals, and benzo-a-pyrene exposure were demonstrated in tissues of these whales. Between 1988 and 1990, 21 tumors were found in 12 out of 24 carcasses. Among these tumors, six were malignant and 15 were benign. The animals were between 1.5 and >29 years of age, and the ages of animals with and without tumors did not differ when two juvenile animals (1.5 and 3.5 years of age) were excluded. Seven other neoplasms had been reported previously in six out of 21 well-preserved carcasses examined in the same laboratory between 1982 and 1987. Overall, 28 of the 75 confirmed tumors reported so far in cetaceans (37%) were from this small population of beluga whales in the St. Lawrence Estuary. Such a high prevalence of tumors would suggest an influence of contaminants through a direct carcinogenic effect and/or a decreased resistance to the development of tumors in this population.


1988 ◽  
Vol 98 (3) ◽  
pp. 287-310 ◽  
Author(s):  
D. Martineau ◽  
A. Lagacé ◽  
P. Béland ◽  
R. Higgins ◽  
D. Armstrong ◽  
...  

2018 ◽  
Vol 285 (1888) ◽  
pp. 20181356 ◽  
Author(s):  
Dana Lynn Moseley ◽  
Graham Earnest Derryberry ◽  
Jennifer Nicole Phillips ◽  
Julie Elizabeth Danner ◽  
Raymond Michael Danner ◽  
...  

Anthropogenic noise imposes novel selection pressures, especially on species that communicate acoustically. Many animals—including insects, frogs, whales and birds—produce sounds at higher frequencies in areas with low-frequency noise pollution. Although there is support for animals changing their vocalizations in real time in response to noise (i.e. immediate flexibility), other evolutionary mechanisms for animals that learn their vocalizations remain largely unexplored. We hypothesize that cultural selection for signal structures less masked by noise is a mechanism of acoustic adaptation to anthropogenic noise. We test this hypothesis by presenting nestling white-crowned sparrows (Zonotrichia leucophyrs) with less-masked (higher-frequency) and more-masked (lower-frequency) tutor songs either during playback of anthropogenic noise (noise-tutored treatment) or at a different time from noise playback (control treatment). As predicted, we find that noise-tutored males learn less-masked songs significantly more often, whereas control males show no copying preference, providing strong experimental support for cultural selection in response to anthropogenic noise. Further, noise-tutored males reproduce songs at higher frequencies than their tutor, indicating a distinct mechanism to increase signal transmission in a noisy environment. Notably, noise-tutored males achieve lower performance songs than their tutors, suggesting potential costs in a sexual selection framework.


Author(s):  
Richard St-Louis ◽  
Stephen de Mora ◽  
�milien Pelletier ◽  
Bill Doidge ◽  
Daniel Leclair ◽  
...  

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