Instrumentation & Measurement Magazine 24-3 - 63

Table 2 - Common instrumentation technologies for NARW detection and monitoring
Instrument/
Technology

Description

Advantages

Aerial
surveillance

Aircrafts fly in a pre-defined
pattern over the area of interest.
Highly trained observers in the
planes watch the area of interest
in seeking of whales blows. Highresolution cameras can be used to
take photographs.

Potential to cover large areas in a
short time

High cost, risk and noise.
Moreover, missions have a
limited duration time and are
subject to weather conditions.

Drones

Used in boat-based missions.
Drones can be equipped with
different sensors and controlled
to fly closer to and collect data
from detected right whales.

Low cost and can fly closer to the
monitored whale

Low independency and
autonomy. Boat-based missions
are needed to have the drone
operator in the proximity to
control it.

Disadvantages

Hydrophones

Underwater microphones used
to detect and record underwater
noise.

Cost effective as compared to
other underwater monitoring
technologies

Just record sound and pressure
differences, do not distinguish
the entity producing the received
sound. Records differ in terms
of signal amplitude and ambient
noise, given the used acoustic
equipment, deployment
characteristics, and area where
hydrophones are deployed,
which pose critical challenges
for used algorithms aimed at
identifying NARW upcalls.

Gliders

Mobile device equipped with
many instruments provide
spatiotemporal measurements of
variables of interest in a near realtime manner.

Provide spatiotemporal data and
from diverse water columns

Might have limited mission
lifetime as compared to stationary
hydrophones.

Infrared
cameras

Identify whales while at the
sea surface by comparing the
temperature different of the
animal and its surrounding water
and air.

Work independently of daylight,
i.e., it can identify whales even
in the darkness. Moreover,
it shows good performance
even in distinct environmental
conditions.

They might misclassify boats
and birds as marine mammals.
Specialized software tools are
necessary to process image and
distinguish those entities.

Aerial Surveillance
Aerial surveillance is one of the traditional approaches for detecting NARWs. In this approach, survey planes commonly fly
in a grid-like pattern over the area to be covered. In the plane,
marine mammal observers attentively watch over the area to
seek the V-shaped blows of right whales and record important pieces of information when whales are sighted, such as
the number of whales, their position, dive times and evidence
of entanglements and injuries. Observers may also take pictures to identify the detected whales. Moreover, planes might
be equipped with high-power magnification cameras used to
take photographs to determine if the animals are right whales
and identify spotted individuals. NARWs can be identified by
their unique callosities on their bodies.
May 2021

The main advantage of aerial surveillance is the possibility
of covering large areas in such a short amount of time. In fact,
DFO and Transport Canada rely on aerial surveillance missions in the Gulf of St. Lawrence, Bay of Fundy, Scotian Shelf
and the southern coast of Newfoundland, with planes flying
at levels between 1,500 and 800 feet, as one of the approaches
for detecting the presence of right whales in shipping lanes.
When right whales are spotted in these areas, interim slowdown measures are implemented to reduce the likelihood of
fatal strikes and encourage vessels to take routes where right
whales are not present [11]. Detecting right whales through
aerial surveillance is a difficult task. Thus, past data is used
to improve the likelihood of encountering NARWs. The past
data might come from hydrophones mounted on buoys used

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