Emptying the Oceans: A Summary of Industrial Whaling Catches in the 20th Century

Rocha, Robert C; Clapham, Phillip J.; Ivashchenko, Yulia V.

doi:10.7755/mfr.76.4.3

Cited by 126 publications

(101 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3a). Whaling harvest counts decreased 75% for fin, humpback, and blue whales in the Northern Hemisphere during this period 26 . This period of dwindling harvest counts coincided with the lowest baseline-corrected cortisol concentrations measured from whale earplugs over the 20th century (27% above the baseline value; Fig.…”

Section: Resultsmentioning

confidence: 88%

“…The association between total whaling counts during the 20th century 26 and baseline-corrected cortisol concentrations (Fig. 3a) was evaluated collectively for all three whale species (years 1900–1999 n = 942 laminae; Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Commercial whaling increased in scope and became increasingly more efficient during the 20th century, resulting in a 45% increase in fin whale harvests and a 70% increase in humpback harvests when compared to the 19th century 26 . This efficacy was maintained during the decade of the 1930s, where ∼50,000 fin, humpback, and blue whales were harvested from Northern Hemisphere waters 26 . During this period, between world wars, maximum baseline-corrected cortisol levels were achieved (53% above baseline) in earplugs, mirroring maximum harvest take of whales (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…N = 1084 lamina; 1870s, n = 17; 1880s, n = 20; 1890s, n = 20; 1900s, n = 35; 1910s, n = 32; 1920s, n = 71; 1930s, n = 144; 1940s, n = 225; 1950s, n = 212; 1960s, n = 89; 1970s, n = 60; 1980s, n = 60; 1990s, n = 60; 2000s, n = 27; 2010s, n = 12). Whaling counts (total deaths) and ±SE calculated from Rocha et al 26 . b Relationship between 5-year mean baseline-corrected cortisol (± SE) and 5-year mean whaling counts (± SE) for the 20th century ( r 2 value = 0.78).…”

Section: Resultsmentioning

confidence: 99%

“…Once post-war whaling resumed in the 1950s, the number of whales harvested drastically increased and peaked in the early 1960s, with nearly 150,000 animals harvested 26 . During the early 1960s, baseline-corrected cortisol peaked to a maximum 68%, denoting the highest mean baseline-corrected stress values over the 20th century (Fig.…”

Section: Resultsmentioning

confidence: 99%

See 4 more Smart Citations

Baleen whale cortisol levels reveal a physiological response to 20th century whaling

Trumble

Norman²,

Crain

et al. 2018

Nat Commun

View full text Add to dashboard Cite

One of the most important challenges researchers and managers confront in conservation ecology is predicting a population’s response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970–2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.

show abstract

Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Baleen whale cortisol levels reveal a physiological response to 20th century whaling

Trumble

Norman²,

Crain

et al. 2018

Nat Commun

View full text Add to dashboard Cite

show abstract

Boom to bust? Implications for the continued rapid growth of the eastern Australian humpback whale population despite recovery

2019

View full text Add to dashboard Cite

Despite heavy overexploitation and near extirpation, some populations of large whales are recovering. Monitoring their recovery has important implications for conservation, management and our understanding of population dynamics and recovery in large mammals. The eastern Australian population of humpback whales was hunted to near‐extirpation by the early 1960s. Despite this, the population started to recover, and structured surveys were initiated in the 1980s. These surveys comprise one of the longest and most consistent series of surveys of a population of whales in the world. Collectively, they have demonstrated a rapid recovery of the population with a long‐term average rate of increase of 10.9% per annum. Here, we present the results of the last three surveys, conducted in 2007, 2010 and 2015. The 2015 survey shows that the population is essentially recovered, with abundance estimated at 24,545 whales (95% confidence interval 21,631–27,851), and yet continues to grow at a rapid rate. Modeling the rate of growth and abundance suggests that either the whales are heading for a higher than expected abundance of at least 40,000 whales or that an irruption may occur with models suggesting a peak in whale abundance in 2021–2026. Understanding the possible future scenarios of this population is critical to its management. This situation also presents a rare opportunity to study in detail the growth of a well‐defined population of large mammal as it recovers from severe depletion.

show abstract

From land and sea, long‐term data reveal persistent humpback whale (Megaptera novaeangliae) breeding habitat in New Caledonia

Derville

Torres

Dodémont³

et al. 2019

Aquatic Conservation

View full text Add to dashboard Cite

Long‐term monitoring is a prerequisite to understanding and protecting long‐lived species such as cetaceans. In New Caledonia, South Pacific, an endangered sub‐population of humpback whales (Megaptera novaeangliae) seasonally congregates for mating and nursing during the austral winter. For more than two decades, dedicated surveys have been conducted at sea and from land to monitor humpback whale presence in a coastal breeding site, the South Lagoon. Methods were developed to investigate space use patterns and their temporal variations over the long term using a joint dataset of boat‐based and land‐based observations (1995–2017). A total of 2651 humpback whale groups were observed, including 1167 from land and 1484 at sea (of which 30% were initially detected by the land‐based observers). Humpback whales displayed a persistent space use pattern over this 23 year period, consistent social composition over the years, and an increase in the group encounter rates from land and at sea. The core area of use by humpback whales was characterized in the austral winter by stable and relatively low sea surface temperature (22°C). Whales consistently occupied nearshore waters from 10 to 200 m deep and open to the ocean. Waters surrounded by dense coral reefs were avoided. Although humpback whale distribution patterns were persistent and occurrence was found to increase over two decades, a mismatch between humpback whale critical habitat and marine protected areas was revealed. In the context of growing anthropogenic pressure from tourism and industrial development, these findings should be incorporated into local management efforts to protect the endangered Oceania humpback whale in one of its main breeding sites.

show abstract

Emptying the Oceans: A Summary of Industrial Whaling Catches in the 20th Century

Abstract: ABSTRACT-Late 19th century technological advances for capturing whales, when combined with the expansion of processing capabilities in the early

Cited by 126 publications

References 12 publications

Baleen whale cortisol levels reveal a physiological response to 20th century whaling

Baleen whale cortisol levels reveal a physiological response to 20th century whaling

Boom to bust? Implications for the continued rapid growth of the eastern Australian humpback whale population despite recovery

From land and sea, long‐term data reveal persistent humpback whale (Megaptera novaeangliae) breeding habitat in New Caledonia

Contact Info

Product

Resources

About