89
devices can also incorporate high precision environmental
sensors, which are able to record valuable CTD (Conductivity,
Temperature, Depth) data. The collected temperature and
salinity profiles have a relatively good quality and accuracy,
compared to traditional oceanographic measurements, such
as floats and moorings (Boehme et al. 2009). This development meant that studying foraging behavior in relation to
actual environmental conditions, as experienced by the animals, became possible (Fig. 2d) (Biuw et al. 2007; McIntyre
et al. 2011; Lowther et al. 2013; Blanchet et al. 2015;
Labrousse et al. 2015).
Accelerometers and magnetometers can also be coupled
with Argos or GPS devices, providing even more powerful
tools to study animal behavior (Fig. 2e) (Wilson et al. 2008;
Bouten et al. 2013; Cox et al. 2017). These instruments are
able to give extremely detailed information about threedimensional movements and behaviors. More sophisticated
devices have also incorporated a hydrophone for sound recordings of diving predators, such as cetaceans, which enables
researchers to relate their movements to acoustic behavior as
well as to the surrounding soundscape (Fig. 2f) (Nowacek
et al. 2001; Johnson and Tyack 2003; Aguilar Soto et al. 2008;
Wisniewska et al. 2016). Such instruments usually have to be
recovered for data retrieval, but recently other systems have
been developed, which allow the remote downloading of concurrent GPS and accelerometer data at ground base stations
(Bouten et al. 2013). Another exciting and promising approach
is the recent launch of the ICARUS initiative (Icarus Initiative
2018). Specifically-designed ICARUS satellite tags will be
able to record GPS positions as well as tri-axial accelerometer
data and transmit the data to the ICARUS antenna on-board
the International Space Station. The data will then be made
available to the users in near real time via the database
Movebank (see Box 2 for an overview on databases for animal
movement data). These remotely-operating systems enable
the study of migration patterns and habitat use of migratory
species over large spatial and temporal scales in great detail
(Wikelski et al. 2007; Bouten et al. 2013; Stienen et al. 2016;
Wikelski and Tertitski 2016).
For animals that do not regularly come to the surface,
such as fish, pop-up archival transmitting tags (PATs) can be
used (Carlson et al. 2010; Jorgensen et al. 2010; Campana
et al. 2011; Hammerschlag et al. 2011). PATs usually constitute an archival logger and an Argos satellite transmitter, and,
in the case of sharks and other elasmobranchs, are anchored
in the dorsal fin or dorsal musculature (Hammerschlag et al.
2011). The logger records and stores temperature, depth, and
ambient light levels over several months to years. After a preprogrammed period, the tag detaches from the animal and
pops up to the ocean surface. While floating, it transmits the
recorded data to Argos satellites (Hammerschlag et al. 2011).
The animal’s horizontal movements are reconstructed from
the in situ measured sea surface temperature and light levels,
resulting in a daily estimate of latitude and longitude. Since
the location estimate is relatively imprecise, with mean
errors ranging between 60 and 180 km, only large-scale
movements and migrations patterns can be investigated
(Block et al. 2011; Campana et al. 2011; Hammerschlag
et al. 2011). A comparable technology is used to track largescale and often multi-year movements of pinnipeds and flying seabirds, however, this system is not linked to satellites.
Similar to PATs, light level geolocators record light levels
from which locations can be derived. They are relatively
inexpensive and the spatial resolution (ca. 100–200 km) is
often sufficient for wide-ranging species, such as petrels,
albatrosses, terns, or elephant seals (Afanasyev 2004;
Bradshaw et al. 2004; Phillips et al. 2004; Egevang et al.
2010; Weimerskirch et al. 2014).
Acoustic Telemetry
Tracking animals by means of acoustic telemetry was specifically developed for use in marine and freshwater ecosystems.
It is based on the idea that tagged animals, most often fish, are
registered by submerged receiving stations (Donaldson et al.
2014; Hussey et al. 2015). The tag is usually a transmitter,
which is either surgically implanted or attached externally to
the animal and emits signals with a given pulse rate. The
transmitters can be miniscule (<0.5 g in some cases), and can
even be used to tag small or juvenile fish (McMichael et al.
2010). The presence of the animal is recorded when the transBox 2: Links to Online Databases Hosting Marine Animal
Movement Data
Biodiversity.aq—Antarctic biodiversity data base:
http://www.biodiversity.aq
Lifewatch.be—A virtual laboratory for biodiversity
research: http://www.lifewatch.be/
OBIS-SEAMAP—Ocean Biogeographic Information
System
Spatial
Ecological
Analysis
of
Megavertebrate Populations: http://seamap.env.
duke.edu/
Ocean Tracking network: https://members.oceantrack.
org/projects
OCEARCH’s Global Shark Tracker: http://www.
ocearch.org
MEOP—Marine Mammals Exploring the Oceans
from Pole to Pole: http://www.meop.net
MMT—Marine Mammal Tracking: https://www.pangaea.de/?q=project%3Alabel%3AMMT
Movebank: A Database for Animal Tracking Data:
https://www.movebank.org
Bio-telemetry as an Essential Tool in Movement Ecology and Marine Conservation
devices can also incorporate high precision environmental
sensors, which are able to record valuable CTD (Conductivity,
Temperature, Depth) data. The collected temperature and
salinity profiles have a relatively good quality and accuracy,
compared to traditional oceanographic measurements, such
as floats and moorings (Boehme et al. 2009). This development meant that studying foraging behavior in relation to
actual environmental conditions, as experienced by the animals, became possible (Fig. 2d) (Biuw et al. 2007; McIntyre
et al. 2011; Lowther et al. 2013; Blanchet et al. 2015;
Labrousse et al. 2015).
Accelerometers and magnetometers can also be coupled
with Argos or GPS devices, providing even more powerful
tools to study animal behavior (Fig. 2e) (Wilson et al. 2008;
Bouten et al. 2013; Cox et al. 2017). These instruments are
able to give extremely detailed information about threedimensional movements and behaviors. More sophisticated
devices have also incorporated a hydrophone for sound recordings of diving predators, such as cetaceans, which enables
researchers to relate their movements to acoustic behavior as
well as to the surrounding soundscape (Fig. 2f) (Nowacek
et al. 2001; Johnson and Tyack 2003; Aguilar Soto et al. 2008;
Wisniewska et al. 2016). Such instruments usually have to be
recovered for data retrieval, but recently other systems have
been developed, which allow the remote downloading of concurrent GPS and accelerometer data at ground base stations
(Bouten et al. 2013). Another exciting and promising approach
is the recent launch of the ICARUS initiative (Icarus Initiative
2018). Specifically-designed ICARUS satellite tags will be
able to record GPS positions as well as tri-axial accelerometer
data and transmit the data to the ICARUS antenna on-board
the International Space Station. The data will then be made
available to the users in near real time via the database
Movebank (see Box 2 for an overview on databases for animal
movement data). These remotely-operating systems enable
the study of migration patterns and habitat use of migratory
species over large spatial and temporal scales in great detail
(Wikelski et al. 2007; Bouten et al. 2013; Stienen et al. 2016;
Wikelski and Tertitski 2016).
For animals that do not regularly come to the surface,
such as fish, pop-up archival transmitting tags (PATs) can be
used (Carlson et al. 2010; Jorgensen et al. 2010; Campana
et al. 2011; Hammerschlag et al. 2011). PATs usually constitute an archival logger and an Argos satellite transmitter, and,
in the case of sharks and other elasmobranchs, are anchored
in the dorsal fin or dorsal musculature (Hammerschlag et al.
2011). The logger records and stores temperature, depth, and
ambient light levels over several months to years. After a preprogrammed period, the tag detaches from the animal and
pops up to the ocean surface. While floating, it transmits the
recorded data to Argos satellites (Hammerschlag et al. 2011).
The animal’s horizontal movements are reconstructed from
the in situ measured sea surface temperature and light levels,
resulting in a daily estimate of latitude and longitude. Since
the location estimate is relatively imprecise, with mean
errors ranging between 60 and 180 km, only large-scale
movements and migrations patterns can be investigated
(Block et al. 2011; Campana et al. 2011; Hammerschlag
et al. 2011). A comparable technology is used to track largescale and often multi-year movements of pinnipeds and flying seabirds, however, this system is not linked to satellites.
Similar to PATs, light level geolocators record light levels
from which locations can be derived. They are relatively
inexpensive and the spatial resolution (ca. 100–200 km) is
often sufficient for wide-ranging species, such as petrels,
albatrosses, terns, or elephant seals (Afanasyev 2004;
Bradshaw et al. 2004; Phillips et al. 2004; Egevang et al.
2010; Weimerskirch et al. 2014).
Acoustic Telemetry
Tracking animals by means of acoustic telemetry was specifically developed for use in marine and freshwater ecosystems.
It is based on the idea that tagged animals, most often fish, are
registered by submerged receiving stations (Donaldson et al.
2014; Hussey et al. 2015). The tag is usually a transmitter,
which is either surgically implanted or attached externally to
the animal and emits signals with a given pulse rate. The
transmitters can be miniscule (<0.5 g in some cases), and can
even be used to tag small or juvenile fish (McMichael et al.
2010). The presence of the animal is recorded when the transBox 2: Links to Online Databases Hosting Marine Animal
Movement Data
Biodiversity.aq—Antarctic biodiversity data base:
http://www.biodiversity.aq
Lifewatch.be—A virtual laboratory for biodiversity
research: http://www.lifewatch.be/
OBIS-SEAMAP—Ocean Biogeographic Information
System
Spatial
Ecological
Analysis
of
Megavertebrate Populations: http://seamap.env.
duke.edu/
Ocean Tracking network: https://members.oceantrack.
org/projects
OCEARCH’s Global Shark Tracker: http://www.
ocearch.org
MEOP—Marine Mammals Exploring the Oceans
from Pole to Pole: http://www.meop.net
MMT—Marine Mammal Tracking: https://www.pangaea.de/?q=project%3Alabel%3AMMT
Movebank: A Database for Animal Tracking Data:
https://www.movebank.org
Bio-telemetry as an Essential Tool in Movement Ecology and Marine Conservation