Spatial and temporal distribution of cetaceans in the mid-Atlantic waters around the Azores
Silva, Monica A.
Seabra, Maria I.
Baumgartner, Mark F.
Santos, Ricardo S.
MetadataShow full item record
Cetaceans living in offshore waters are under increasing pressure from anthropogenic activities. Yet, due to the lack of survey effort, relatively little is known about the demography or ecology of these populations. Spatial and temporal distribution of cetaceans in mid-Atlantic waters were investigated using a long term dataset collected from boat surveys and land-based observations around the Azores. From 1999 to 2009, 7307 cetacean schools were sighted during 271717 km of survey effort. In 4944 h of land-based observations, 2968 cetacean groups were detected. Twenty-four species were recorded: seven baleen whales, six beaked whales, eight dolphin species, Physeter macrocephalus, Kogia breviceps and K. sima. Overall, Delphinus delphis was the most frequently sighted species but its encounter rate decreased in June- November, coinciding with presence of Stenella frontalis in the region. Tursiops truncatus, P. macrocephalus and Grampus griseus were frequently encountered yearround, whereas large baleen whales showed a distinct peak in encounter rates in March-May. Mesoplodonts were fairly common and appear to be present throughout the year. These findings fill-in a significant gap in the knowledge of cetaceans occurring in a poorly studied region of the North Atlantic, providing much needed data to inform management initiatives.
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Marine Biology Research 10 (2014): 123-137, doi:10.1080/17451000.2013.793814.
Showing items related by title, author, creator and subject.
Spatial and temporal variations in crustal production at the Mid-Atlantic Ridge, 25°N–27°30′N and 0–27 Ma Wang, Tingting; Tucholke, Brian E.; Lin, Jian (John Wiley & Sons, 2015-04-21)We use high-resolution multibeam bathymetry, shipboard gravity, side-scan sonar images, and magnetic anomaly data collected on conjugate flanks of the Mid-Atlantic Ridge at 25°N–27°30′N and out to ~27 Ma crust to investigate ...
Temporal changes in euphausiid distribution and abundance in North Atlantic cold-core rings in relation to the surrounding waters Endo, Yoshinari; Wiebe, Peter H. (2006-10-31)The species composition of euphausiids was investigated in relationship to the hydrographic conditions in the North Atlantic cold-core rings (CCR) and adjacent waters to elucidate species succession in evolving water masses. ...
Kettle, A. James (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-06)A field experiment demonstrated the presence of a diurnal cycle in the concentration of carbon monoxide ([CO]) in the upper ocean at the BATS site. A series of laboratory experiments and numerical simulations were carried ...