A non‐invasive method to assess the impact of electronic tag insertion on stress levels in fishes

Abstract

The present study investigated, for the first time, a non-invasive technique for monitoring cortisol levels in fishes that had been implanted with electronic transmitters. This technique involved the measurement of cortisol released into the water by individual fish. Carp Cyprinus carpio and roach Rutilus rutilus that had been tagged with miniature dummy acoustic transmitters responded to the surgical implantation of the tags with an immediate (1 to 4 h) increase in cortisol concentrations in the water. These amounts of cortisol were higher than in 'handled only' and 'handled and anaesthetized' groups. Estimated cortisol release rates for both species correlated well with the direct measurements in the water. In both species, water cortisol concentration and cortisol release rates returned to pre-stress levels within 12 h of tag-insertion, and remained low for the remainder of the experiment. The calculation of cortisol release rates highlighted a difference of a factor of about four between peak release rates in carp and roach. There was no evident long-term cortisol stress response to the presence of a tag in the body cavity in either species. # 2005 The Fisheries Society of the British Isles

Long-term effects of surgically implanted telemetry tags on the nutritional physiology and condition of wild freshwater fish

“…This research has revealed an immediate stress response to surgery, handling, and anaesthesia, but after approximately 8 to 10 h, the stress levels tend to return to normal (Jepsen et al 2001, Close et al 2003, Lower et al 2005, Feldhaus et al 2008. Furthermore, laboratory studies have examined the consequences of transmitter implantation on growth, swimming performance, and survival of intervals ranging from days to weeks (e.g.…”

“…Levels of glucose, chloride, sodium, and potassium are indicative of stress from handling or anaesthesia, and have been used in many short-term studies of the effects of transmitter devices on fish (Jepsen et al 2001, Close et al 2003, Lower et al 2005, Feldhaus et al 2008. Since there was no significant difference between the telemetered and non-telemetered fish in any of these indicators, it is clear that there was no latent stress response from surgery, handling, and anaesthesia (Wendelaar-Bonga 1997 after 8 to 10 h in laboratory environments (see Wendelaar-Bonga 1997), suggesting that there is no residual or increased stress for fish associated with carrying a telemetry device for several years.…”

Non-invasive measurement of steroids in fish-holding water: important considerations when applying the procedure to behaviour studies

“…The speed of response is probably also dependent on temperature and, in the case of the sex steroids, on the stage of maturation of the gonads, i.e., how much they are 'primed' to respond. It is also important to note that in a flow-through system, there will be a lag between the time that a steroid reaches its maximum release rate and the time that it reaches its maximum concentration in the water (Ellis et al, 2004;Lower et al, 2005).…”

Tag attachment success can be temperature dependent: a case study of the chub mackerel Scomber japonicus

“…Previous studies have shown that physiological stress levels return to normal within few days after tagging [20,21], suggesting that these negative effects have a short duration. Although they are later compensated for, ameliorating these effects is one of the most important challenges for field tagging researchers [22].…”