Publication Date:
2022-05-25
Description:
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.
Description:
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.
Description:
This work
was supported by FEDER funds, through the Competitiveness Factors Operational
Programme – COMPETE, by national funds, through FCT – Foundation for Science
and Technology, under projects CETAMARH (POCTI/BSE/38991/01) and TRACE
(PTDC/MAR/74071/2006), and by regional funds, through DRCT/SRCTE, under
project MAPCET (M2.1.2/F/012/2011). We thank the Azorean Regional Government
for funding POPA, the Shipowners Proprietors and the Association of the Tuna
Canning Industries for their support to the programme. MAS was supported by an
FCT postdoctoral grant (SFRH/BPD/29841/2006), and IC and RP were supported by
doctoral grants SFRH/BD/41192/2007 and SFRH/BD/32520/2006. IMAR-DOP/UAç
is the R&D Unit #531 and part of the Associated Laboratory #9 (ISR) funded through
the pluri-annual and programmatic funding schemes of FCT-MCTES and DRCTAzores.
Keywords:
Cetaceans
;
Spatial and temporal distribution
;
Mid-Atlantic waters
;
Sighting surveys
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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