Advances in acoustic, archival, and satellite tagging of tunas

Movements of Marine Fish and Decapod Crustaceans: Process, Theory and Application

“…The continuous monitoring of environmental variables, such as depth, light, salinity and temperature make it possible to reconstruct the tracks of animals, estimating the time, place and directionality of movements (Friere and González-Gurriarán, 1998). Welch and Eveson (1999) reviewed the techniques used for geopositioning based on variations in light and Gunn and Block (2001) discuss the limitations with regard to geolocating free-ranging fish.…”

“…Traditionally, this has limited the use of Argos to air-breathing marine animals such as mammals and turtles (Marsh and Rathbun, 1990;Priede and French, 1991;Plotkin, 1998;Gillespie, 2001) and some surface-dwelling fish (Priede, 1984). However, the necessity for understanding the movements of fast swimming and deep diving (> 1000 m) pelagic fish that are being exploited by fisheries has resulted in the invention of 'pop-off' transmitter tags that are programmed to detach from the animal and float to the surface to transmit position and archived data (Priede and French, 1991;Gunn and Block, 2001). Together with implanted DSTs these have been used successfully for studies of bluefin tuna (Thunnus thynnus) (Block et al, 1998) and swordfish (Xiphias gladius) (Sedberry and Loefer, 2001).…”

Performance of pop-up satellite archival tags

“…Current-generation PSATs record data on ambient light-level irradiance from which geolocations can be calculated (Musyl et al 2001), along with depth (pressure) and temperature. PSATs are increasingly used in marine fisheries research (Arnold & Dewar 2001, Brill & Lutcavage 2001, Gunn & Block 2001, Thorsteinsson 2002, Bolle et al 2005 to chronicle horizontal and vertical movements (e.g. Lutcavage et al 1999, Domeier et al 2005, Wilson et al 2005, residence times (Domeier 2006, Domeier & Nasby-Lucas 2008, and post-release mortality (Do meier et al 2003, Moyes et al 2006, Swimmer et al 2006) of teleost, elasmobranch, and sea turtle species.…”

“…Microwave Telemetry (MT) and Wildlife Computers (WC) have taken different approaches to implement 'fail-safe' recovery features in PSATs. And in this regard, PSAT function has changed significantly since the reviews of Arnold & Dewar (2001) and Gunn & Block (2001). Contemporary PSATs are programmed to initiate data transmission to the Argos system under 3 conditions: (1) the PSAT remains attached until its programmed pop-up date, at which time an electrolytic breakaway pin in the nosecone corrodes, releasing the PSAT from its tether.…”

“…Despite the widespread adoption of PSATs in marine fisheries research, concerns remain about their reliability and overall performance (Arnold & Dewar 2001, Gunn & Block 2001, Holland & Braun 2003. The vast majority of PSATs (~80%) are shed before their programmed pop-up date (Arnold & Dewar 2001, Gunn & Block 2001), but factors influencing PSAT reporting rates and intermittent data transmission to Argos, and the time PSATs remain attached, are not well understood.…”