http://www.animalbiotelemetry.com The latest research articles published by Animal Biotelemetry 2013-05-06T00:00:00Z Background: Information on European silver eel Anguilla anguilla anatomy was collected to gain information on limitations on size and placement of electronic tags.FindingsTo reduce the eel’s ability to bite its own sutures, it may be an advantage to make surgical incisions close to the head, but this increases the risk of cutting the liver. Recommended placement of an incision was slightly further from the head than one-fourth of the fish’s body length (L T) to avoid damaging the liver. Long, flexible tags comprising various components can be adjusted to the narrow body cavity and undulating movements of eels. There was space for surgically implanting a 100 mm long tag (11 mm in diameter) in the body cavity of eels with L T ≥380 mm. During gastric tagging, tag length is limited by stomach length. Silver eels with L T 380 to 998 mm had stomach lengths of 47 to 185 mm, indicating that there was space for short gastric tags in the smallest eels, but that there was space for relatively long tags in larger eels. The distance from the snout to the start of the stomach constituted 15 to 23% of L T, indicating how far the transmitter should be inserted during tagging. Conclusion: This information aids the development of tags and tagging methods that consider the unique morphological and behavioral features of eels. http://www.animalbiotelemetry.com/content/1/1/6 Finn Økland Eva Thorstad Animal Biotelemetry 2013, null:6 2013-05-06T00:00:00Z doi:10.1186/2050-3385-1-6 /content/figures/2050-3385-1-6-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 6 2013-05-06T00:00:00Z XML Considerable technical developments over the past half century have enabled widespread application of electronic tags to the study of animals in the wild, including in freshwater environments. We review the constraints associated with freshwater telemetry and biologging and the technical developments relevant to their use. Technical constraints for tracking animals are often influenced by the characteristics of the animals being studied and the environment they inhabit. Collectively, they influence which and how technologies can be used and their relative effectiveness. Although radio telemetry has historically been the most commonly used technology in freshwater, passive integrated transponder (PIT) technology, acoustic telemetry and biologgers are becoming more popular. Most telemetry studies have focused on fish, although an increasing number have focused on other taxa, such as turtles, crustaceans and molluscs. Key technical developments for freshwater systems include: miniaturization of tags for tracking small-size life stages and species, fixed stations and coded tags for tracking large samples of animals over long distances and large temporal scales, inexpensive PIT systems that enable mass tagging to yield population- and community-level relevant sample sizes, incorporation of sensors into electronic tags, validation of tag attachment procedures with a focus on maintaining animal welfare, incorporation of different techniques (for example, genetics, stable isotopes) and peripheral technologies (for example, geographic information systems, hydroacoustics), development of novel analytical techniques, and extensive international collaboration. Innovations are still needed in tag miniaturization, data analysis and visualization, and in tracking animals over larger spatial scales (for example, pelagic areas of lakes) and in challenging environments (for example, large dynamic floodplain systems, under ice). There seems to be a particular need for adapting various global positioning system and satellite tagging approaches to freshwater. Electronic tagging provides a mechanism to collect detailed information from imperilled animals and species that have no direct economic value. Current and future advances will continue to improve our knowledge of the natural history of aquatic animals and ecological processes in freshwater ecosystems while facilitating evidence-based resource management and conservation. http://www.animalbiotelemetry.com/content/1/1/5 Steven Cooke Jonathan Midwood Jason Thiem Peter Klimley Martyn Lucas Eva Thorstad John Eiler Chris Holbrook Brendan Ebner Animal Biotelemetry 2013, null:5 2013-05-01T00:00:00Z doi:10.1186/2050-3385-1-5 /content/figures/2050-3385-1-5-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 5 2013-05-01T00:00:00Z XML Background: Transmitters used in telemetry studies are typically surgically implanted into the coelom of fish. When large numbers of fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools (such as scalpels, forceps, needle holders and sutures) to be sterilized or, at minimum, disinfected between each use to minimize the transfer of pathogens. Chemicals are commonly used for disinfection but they can potentially harm fish and surgeons. UV radiation could provide a safe and more effective means for disinfection. The efficacy of UV radiation was determined for disinfecting surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. The organisms include Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, the causative agents of ulcer disease, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively. Results: In the first experiment, forceps were exposed to three species of bacteria at three varying concentrations. After exposure, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then radiated for three different time periods – 2, 5 or 15 minutes. UV radiation exposures at all durations were effective at killing all three species of bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 minutes was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate-method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations. Conclusions: Collectively, this study shows that UV radiation appears to be an effective disinfection method for some surgical tools. However, we do not recommend using this method for tools that have overlapping parts, such as needle holders, or other structures that cannot be exposed directly to UV radiation. http://www.animalbiotelemetry.com/content/1/1/4 Ricardo Walker Meng Markillie Alison Colotelo David Geist Marybeth Gay Christa Woodley Brad Eppard Richard Brown Animal Biotelemetry 2013, null:4 2013-04-04T00:00:00Z doi:10.1186/2050-3385-1-4 Effective disinfection in fish surgery <p>Evidence suggests that ultraviolet radiation is an efficient form of disinfection for the tools used in surgically implanting transmitters in fish. This method could provide a safer and more effective means of sterilization of surgical tools than the chemicals used currently, which can be harmful to fish. </p> /content/figures/2050-3385-1-4-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 4 2013-04-04T00:00:00Z XML Background: Four methods for attaching pop-up satellite transmitters to European eel were tested in the laboratory by recording long-term tag retention, growth and survival; short-term behavioral responses; and physical damage from attachments. Results: All eels survived until they lost their tag, or until end of the six-month study. Specific growth rate did not differ between tagged fish and controls. Tag retention varied from 0% to 100% among attachment methods. A tagging method that uses the strength of the eel skin by attaching the tag to the skin at three points is recommended for ocean migration studies based on a long tag retention time, minimal behavioral reactions, negligible damage to the swimming muscle, and minimal physical damage both for fish retaining and losing the tag. Although tag retention was 50% over six months, those losing their tags still retained them for 114 to 134 days. Another method had higher tag retention (100%), but required the use of steel wires that moved upwards through the muscle over time. This method was regarded as less suitable because of a strong behavioral reaction in the first two days after tagging and damage to the swimming muscle. Results from 275 silver eels released on European coasts equipped with pop-up satellite transmitters or similarly sized pop-up data storage tags to study the ocean spawning migration indicated a large premature tag release. This was partly related to mechanical tag loss, but probably mainly to a high predation rate (>20% confirmed predations of eels with pop-up satellite transmitters). Mean time to premature tag release was 14 to 21 days (maximum nine months). Conclusions: Laboratory and field data showed that pop-up satellite transmitters attached to eels can remain attached for six to nine months, but that tag retention is a challenge. Hiding behavior in a structured habitat increased the risk of entanglement and tag loss. In ocean migration studies, consideration should be given to transportation and release off shore instead of in shallower areas where they are more likely to seek the seabed and hide in structured habitats. Behavioral reactions indicate that data recorded during the first two to three days after tagging may not reflect natural behavior. http://www.animalbiotelemetry.com/content/1/1/3 Finn Økland Eva Thorstad Håkan Westerberg Kim Aarestrup Julian Metcalfe Animal Biotelemetry 2013, null:3 2013-04-04T00:00:00Z doi:10.1186/2050-3385-1-3 How to attach satellite transmitters to European eel <p>The best method of fitting tags into the peritoneum of long and slender European eels has been investigated according to a number of criteria. Researchers considered long-term tag retention, growth and survival, short term behavioural responses, and physical damage from attachments.</p> /content/figures/2050-3385-1-3-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 3 2013-04-04T00:00:00Z XML Background: Satellite tagging programs have provided detailed information about the migratory patterns of northeastern Pacific white sharks, revealing a seasonal migration between a vast offshore region and coastal aggregation sites. Although adult males undergo annual round-trip migrations, photo-identification programs have noted that sexually mature females may only visit coastal aggregation sites once every 2 years, a behavior that is presumably linked to an estimated 18-month gestation period. The whereabouts of females during their full 2-year migration were previously unknown, because of the limited battery capacity of satellite pop-up tags. Results: Through the use of satellite-linked radio-telemetry tags with multi-year tracking capability, we describe the 2-year migratory pattern for four mature female white sharks tagged at Guadalupe Island, Mexico. The 2-year migration comprised four phases: 1) an Offshore Gestation Phase (which had an average duration of 15.5 months; 2) a Pupping Phase, which occurred along the Mexican coast between the months of April and August; 3) a Pre-Aggregation Phase (when the females were in transition between the Pupping Phase and Guadalupe Island; and 4) the Guadalupe Island Aggregation Phase, which began when the mature females arrived at Guadalupe Island between late September and early October. Conclusions: Long-term satellite tracking of mature female white sharks highlighted the connectivity between a single presumed mating site at Guadalupe Island, and two widely separated pupping sites along the Mexican coast. The Offshore Gestation Phase provided evidence that the females remained offshore for up to 16 months during their 2-year migration cycle. The Pupping Phase along the Mexican coast coincided with the seasonal presence of young-of-the-year white sharks along the coast of North America, and with a presumed gestation period of 18 months, this placed mating between October and January, during the period when white sharks are known to be at Guadalupe Island. Tracking data during the time sharks were offshore showed that mature males and females are spatially segregated, except for their concurrent seasonal presence at Guadalupe Island. These discoveries provide important new details about the complete life history of northeastern Pacific white sharks while identifying crucial regions in which young-of-the-year, juveniles and adult females are most vulnerable. http://www.animalbiotelemetry.com/content/1/1/2 Michael Domeier Nicole Nasby-Lucas Animal Biotelemetry 2013, null:2 2013-04-04T00:00:00Z doi:10.1186/2050-3385-1-2 The 2 year migration of female great white sharks <p>Recent advances in tagging technology have enabled the widely separated migratory paths of white sharks to be shown for successive years based on the positioning of a tag fitted on the dorsal fin that transmits when the shark rises to the sea surface and the ARGOS satellite is overhead. Their two year migration pattern has been tracked, revealing important sites for conservation, associated with pupping along the mexican coast.</p> <p>&nbsp;Areas of conservation concern are identified where both adult and juvenile sharks are most vulnerable and should be protected.</p> /content/figures/2050-3385-1-2-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 2 2013-04-04T00:00:00Z XML Not applicable http://www.animalbiotelemetry.com/content/1/1/1 A. Peter Klimley Animal Biotelemetry 2013, null:1 2013-04-04T00:00:00Z doi:10.1186/2050-3385-1-1 Why publish Animal Biotelemetry? <p>In this introductory editorial from the Editor-in-Chief, Pete Klimley, the aims and purpose of Animal Biotelemetry are discussed in the context along with a brief account of telemetry research and recent advances in this field.</p> /content/figures/2050-3385-1-1-toc.gif Animal Biotelemetry 2050-3385 ${item.volume} 1 2013-04-04T00:00:00Z XML