Purpose:
Estimate abundance for as many species as possible.
SUPPLEMENTAL INFORMATION: Data correction 03/08/06
Humback whale was mistakenly linked to Balaenidae (180531). It is now linked to
Megaptera novaeangliae (180530). The survey was flown using line transect
methodology. There were three observers at all times, left bubble window, right
bubble window and one
... observer looking straight down in a belly window
position. Their were four observer positions, left, right, belly, and on break.
Observers rotated positions on the half hour unless the end of a trackline
would fall within 5-10 minutes of the half hour interval. A fifth person was
the designated recorder and remained at the recording station throughout the
flight. The observers reported sightings of all marine mammals, fish, and boats
encountered. The marine mammals were identified to species and their angle of
inclination (when perpendicular to the aircraft) was measured with an
electronic protractor. Angles above 60° were recorded with 10° intervals marked
on the bubble. The observers scanned from the horizon to the trackline,
concentrating their effort from 2 miles inward. The belly window observer was
limited to a 28° view on both sides of the trackline and these sightings were
recorded as the degrees right or left. Weather conditions were recorded at the
beginning of each transect and whenever conditions changed during the transect.
Conditions recorded include: cloud cover (% cover), Beaufort sea state
(recorded in tenths), observer glare (none, slight, moderate, severe), and
overall quality of sighting conditions (excellent, good, moderate, fair, poor).
Observer positions were recorded at each rotation. Surface water temperature
was recorded using an infra-red temperature sensor in the belly of the aircraft
and recorded with time every minute. The computers used for sightings data and
for the sea surface temperature were synchronized with the GPS for time. The
survey was flown at an altitude of 600 feet and at 110 knots over the water.
All animals seen within two miles of the trackline were identified to species
and counted (aircraft broke from survey effort in cases of uncertain identity).
Unidentified animals beyond two miles from the trackline were not examined for
species identification. The survey flew either east/west or north/south
tracklines with ten mile spacing. These tracklines were planned to cross lines
of bathymetry rather than follow them. Survey conditions required Beaufort sea
state 3 or less, some small sections of tracklines were conducted up to
Beaufort 4, however only if conditions were known to improve to survey
conditions on 80% or more of the entire days flight. Flights were planned to
center on 1200 hours (noon) to minimize glare for the observers, on some
occasions flights were begun earlier or later to minimize sea state, fog
conditions or wind. Flights were aborted when observer viewing quality dropped
below Fair for two or more observers. Flight duration depended on the aircraft
load conditions and transect lengths. On days when the flight would return to
the same airport and personal luggage was not transported additional fuel could
be carried and survey days of 6 hours were possible. On days when transiting to
a new location, flight duration was limited to approximately 5 hours. Some
flights were purposely shorter than the maximum when the transect lengths
prohibited another full line to be flown.The aerial survey was comprised of
eighteen flight days over the survey period, with nearly 11,000 nautical miles
of transect lines flown. Three days were aborted early due to weather and
observer quality issues and those lines repeated on following survey days.
Approximately 79% of the survey was flown in Beaufort 2.0 or less and only 5%
in Beaufort 3.1 - 4.0. There were thousands of recorded sightings over the
survey and from these there were a total of 4802 individuals of marine mammals,
comprising 17 species. Additionally we counted 315 turtles from three species
(Loggerhead, Leatherback and Kemps-Ridleys), and over five thousand fish, rays
and sharks from 9 species groups. Sightings of boats, fishing gear, and debris
have not been summarized here but are available in the database for interested
parties.
CURRENTNESS REFERENCE: ground condition
SPATIAL REFERENCE INFORMATION -
GEODETIC MODEL
Horizontal Datum Name: D_WGS_1984
Ellipsoid Name: WGS_1984
Semi-major Axis: 6378137.000000
Denominator of Flattening Ratio: 298.257224 
