Modeling the foraging habitat of humpback whales
Knowing how species will respond to environmental variability and climate change requires understanding the factors that influence their distribution and movement patterns. I investigated the processes that drive individuals to concentrate in specific areas of their home range by modeling encounter...
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ftcanadathes:oai:collectionscanada.gc.ca:BVAU.2429/23486 2023-05-15T13:56:29+02:00 Modeling the foraging habitat of humpback whales Dalla Rosa, Luciano 2010-04-14T15:42:30Z http://hdl.handle.net/2429/23486 eng eng University of British Columbia http://hdl.handle.net/2429/23486 Electronic Thesis or Dissertation 2010 ftcanadathes 2014-03-30T00:45:37Z Knowing how species will respond to environmental variability and climate change requires understanding the factors that influence their distribution and movement patterns. I investigated the processes that drive individuals to concentrate in specific areas of their home range by modeling encounter rates of humpback whales (Megaptera novaeangliae) in relation to environmental variables using GIS tools, generalized additive models, and remote sensing and in situ data. I conducted this work at two foraging areas: the coastal waters of British Columbia, Canada, and the Bransfield and Gerlache Straits, Antarctica. Humpback whales in British Columbia were strongly associated with latitude and bathymetric features. The relationships with remotely sensed variables reflecting primary productivity were not consistent, but higher numbers of whales seemed to be associated with higher productivity. In fact, the highest concentrations of humpback whales appeared to reflect areas where concentration and retention processes lead to higher biological productivity, including south Dixon Entrance, middle and southwestern Hecate Strait and off Juan de Fuca Strait. Humpback whales in the Southern Ocean also preferred areas of enhanced biological productivity. In Gerlache Strait, humpback whales were associated with areas of higher chlorophyll-a concentration in the central and northern sections of the strait, which also corresponded to relatively higher temperatures and shallower mixed layer depths for the in situ data. In Bransfield Strait, humpback whales appeared to prefer the near-frontal zones and the deep basins, where surface waters are influenced by the Bransfield Current. Interannual variability in both humpback and minke whale encounter rates in Gerlache Strait was correlated with the Oceanic Niño Index, the oceanic component of ENSO. In addition to investigating species-habitat relationships with statistical models, I conducted the first study to describe the satellite-monitored movements of humpback whales on their feeding grounds along the Antarctic Peninsula. Results showed considerable individual variation in direction, speed and range of movements, and an overall pattern characterized by short- and long-distance movements between presumed foraging areas with relatively short residency times. All told, the results of my research show that humpback whale distribution within foraging habitat is influenced by physical and biological variables that enhance biological productivity. Thesis Antarc* Antarctic Antarctic Peninsula Antarctica Bransfield Strait Humpback Whale Megaptera novaeangliae minke whale Southern Ocean Theses Canada/Thèses Canada (Library and Archives Canada) Antarctic Southern Ocean The Antarctic Antarctic Peninsula Bransfield Strait Canada British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Gerlache ENVELOPE(99.033,99.033,-66.500,-66.500) Gerlache Strait ENVELOPE(-62.333,-62.333,-64.500,-64.500) Dixon Entrance ENVELOPE(-132.003,-132.003,54.416,54.416) Hecate Strait ENVELOPE(-131.170,-131.170,53.500,53.500) |
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Open Polar |
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Theses Canada/Thèses Canada (Library and Archives Canada) |
op_collection_id |
ftcanadathes |
language |
English |
description |
Knowing how species will respond to environmental variability and climate change requires understanding the factors that influence their distribution and movement patterns. I investigated the processes that drive individuals to concentrate in specific areas of their home range by modeling encounter rates of humpback whales (Megaptera novaeangliae) in relation to environmental variables using GIS tools, generalized additive models, and remote sensing and in situ data. I conducted this work at two foraging areas: the coastal waters of British Columbia, Canada, and the Bransfield and Gerlache Straits, Antarctica. Humpback whales in British Columbia were strongly associated with latitude and bathymetric features. The relationships with remotely sensed variables reflecting primary productivity were not consistent, but higher numbers of whales seemed to be associated with higher productivity. In fact, the highest concentrations of humpback whales appeared to reflect areas where concentration and retention processes lead to higher biological productivity, including south Dixon Entrance, middle and southwestern Hecate Strait and off Juan de Fuca Strait. Humpback whales in the Southern Ocean also preferred areas of enhanced biological productivity. In Gerlache Strait, humpback whales were associated with areas of higher chlorophyll-a concentration in the central and northern sections of the strait, which also corresponded to relatively higher temperatures and shallower mixed layer depths for the in situ data. In Bransfield Strait, humpback whales appeared to prefer the near-frontal zones and the deep basins, where surface waters are influenced by the Bransfield Current. Interannual variability in both humpback and minke whale encounter rates in Gerlache Strait was correlated with the Oceanic Niño Index, the oceanic component of ENSO. In addition to investigating species-habitat relationships with statistical models, I conducted the first study to describe the satellite-monitored movements of humpback whales on their feeding grounds along the Antarctic Peninsula. Results showed considerable individual variation in direction, speed and range of movements, and an overall pattern characterized by short- and long-distance movements between presumed foraging areas with relatively short residency times. All told, the results of my research show that humpback whale distribution within foraging habitat is influenced by physical and biological variables that enhance biological productivity. |
format |
Thesis |
author |
Dalla Rosa, Luciano |
spellingShingle |
Dalla Rosa, Luciano Modeling the foraging habitat of humpback whales |
author_facet |
Dalla Rosa, Luciano |
author_sort |
Dalla Rosa, Luciano |
title |
Modeling the foraging habitat of humpback whales |
title_short |
Modeling the foraging habitat of humpback whales |
title_full |
Modeling the foraging habitat of humpback whales |
title_fullStr |
Modeling the foraging habitat of humpback whales |
title_full_unstemmed |
Modeling the foraging habitat of humpback whales |
title_sort |
modeling the foraging habitat of humpback whales |
publisher |
University of British Columbia |
publishDate |
2010 |
url |
http://hdl.handle.net/2429/23486 |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) ENVELOPE(99.033,99.033,-66.500,-66.500) ENVELOPE(-62.333,-62.333,-64.500,-64.500) ENVELOPE(-132.003,-132.003,54.416,54.416) ENVELOPE(-131.170,-131.170,53.500,53.500) |
geographic |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Bransfield Strait Canada British Columbia Gerlache Gerlache Strait Dixon Entrance Hecate Strait |
geographic_facet |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Bransfield Strait Canada British Columbia Gerlache Gerlache Strait Dixon Entrance Hecate Strait |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Bransfield Strait Humpback Whale Megaptera novaeangliae minke whale Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Bransfield Strait Humpback Whale Megaptera novaeangliae minke whale Southern Ocean |
op_relation |
http://hdl.handle.net/2429/23486 |
_version_ |
1766263990411853824 |