Entanglement is a costly life-history stage in large whales
MetadataShow full item record
KeywordBioenergetics; Blubber; Capital breeder; Cetacean; Emergency life-history stage; Energy storage; Eubalaena glacialis; Marine mammal
Individuals store energy to balance deficits in natural cycles; however, unnatural events can also lead to unbalanced energy budgets. Entanglement in fishing gear is one example of an unnatural but relatively common circumstance that imposes energetic demands of a similar order of magnitude and duration of life-history events such as migration and pregnancy in large whales. We present two complementary bioenergetic approaches to estimate the energy associated with entanglement in North Atlantic right whales, and compare these estimates to the natural energetic life history of individual whales. Differences in measured blubber thicknesses and estimated blubber volumes between normal and entangled, emaciated whales indicate between 7.4 × 1010 J and 1.2 × 1011 J of energy are consumed during the course to death of a lethal entanglement. Increased thrust power requirements to overcome drag forces suggest that when entangled, whales require 3.95 × 109 to 4.08 × 1010 J more energy to swim. Individuals who died from their entanglements performed significantly more work (energy expenditure × time) than those that survived; entanglement duration is therefore critical in determining whales’ survival. Significant sublethal energetic impacts also occur, especially in reproductive females. Drag from fishing gear contributes up to 8% of the 4-year female reproductive energy budget, delaying time of energetic equilibrium (to restore energy lost by a particular entanglement) for reproduction by months to years. In certain populations, chronic entanglement in fishing gear can be viewed as a costly unnatural life-history stage, rather than a rare or short-term incident.
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecology and Evolution 7 (2017): 92–106, doi:10.1002/ece3.2615.
Suggested CitationEcology and Evolution 7 (2017): 92–106
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Cornioley, Tina; Jenouvrier, Stephanie; Borger, Luca; Weimerskirch, Henri; Ozgul, Arpat (The Royal Society, 2017-05-03)One of the predicted consequences of climate change is a shift in body mass distributions within animal populations. Yet body mass, an important component of the physiological state of an organism, can affect key life-history ...
Extreme climate events and individual heterogeneity shape life-history traits and population dynamics Jenouvrier, Stephanie; Peron, Clara; Weimerskirch, Henri (Ecological Society of America, 2015-11)Extreme climatic conditions and their ecological impacts are currently emerging as critical features of climate change. We studied extreme sea ice condition (ESIC) and found it impacts both life-history traits and population ...
Herrera, Marcela; Nanninga, Gerrit; Planes, Serge; Jones, Geoffrey P.; Thorrold, Simon R.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L. (The Royal Society, 2016-08-09)The persistence and resilience of many coral reef species are dependent on rates of connectivity among sub-populations. However, despite increasing research efforts, the spatial scale of larval dispersal remains unpredictable ...