Evaluating passive integrated transponder tags for tracking movements of round gobies

Abstract –  The round goby ( Neogobius melanostomus Pallas) is an invasive species in North America and Europe. We evaluated the efficacy of passive integrated transponder (PIT) tags for marking round gobies and tracking their movements with a portable underwater antenna in shallow areas (≤1 m) of a lake. Tagging did not markedly decrease growth of fish <105 mm; however, growth decreased unexpectedly for tagged fish ≥105 mm during the final sampling period. Nevertheless, tagging did not increase mortality regardless of size class, and tag retention was 100% for caged fish. Tagged round gobies in a 20 × 20-m² block net avoided detection by the portable underwater antenna, and a high proportion of fish probably escaped from the net, suggesting that round gobies may be more mobile than previously reported. In conclusion, PIT tags are a viable method for individually marking round gobies, but detecting tagged round gobies with a portable underwater antenna, given current technology, does not appear promising in shallow areas with low habitat complexity.     

Tagging effects on three non-native fish species in England (Lepomis gibbosus, Pseudorasbora parva, Sander lucioperca) and of native Salmo trutta

Abstract –  To address the dearth of information on tagging effects and long-term survivorship of tagged fish in native and introduced species, laboratory and field investigations were undertaken on three non-native fish species (pumpkinseed Lepomis gibbosus ; topmouth gudgeon Pseudorasbora parva ; pikeperch Sander lucioperca ) tagged with coded-wire (CW), passive integrated transponder (PIT), radio (RT) telemetry and/or acoustic tags (AT), with survivorship of native brown trout ( Salmo trutta ) examined in the field. Laboratory results revealed high survivorship following tag attachment/insertion and resumption of feeding within 24–48 h of tagging (all mortalities could be attributed to an unrelated outbreak of fungal infection), with retention rates being high in both pumpkinseed and pikeperch but low in topmouth gudgeon (excluded from field studies). In the field, short-term post-operation survival was high in pikeperch, pumpkinseed and brown trout. In pumpkinseed and trout, 100% of RT fish survived a 24–30 day tracking study, with 60% and 80%, respectively, recaptured alive at least 3 months post-tagging. Of PIT tagged pumpkinseed, 44% were recaptured (after 6–18 months), with small-sized, CW-tagged fish (0.38 g weight) captured up to 1 year after tagging. In pikeperch, all AT fish except one (the smallest specimen) survived their full expected tracking period (i.e. tag life) – the single lost specimen survived at least half of its expected tracking period (i.e. 6 month battery life). Overall, the tagging methods used were highly effective in pumpkinseed and pikeperch, showing good retention and survival, but PIT tagging of topmouth gudgeon was plagued by low survivorship and tag rejection.     

Effectiveness of four methods for tagging juveniles of farm-reared gilthead sea bream, Sparus aurata, L.

This study tested different tags for each size of farm-reared gilthead sea bream, Sparus aurata L. juveniles, used in enhancement programmes. The following tags were tested: dye mark, fingerling tag, opercular tag, anchor tag A (filament diameter of 1.20 mm) and anchor tag B (0.85 mm). Tag/mark retention, wounds produced by the tag, ease of application, ease of detection and cost were examined. Epidermal dye marks had poor retention and detection rates. Of the tags tested, retention was greater for the anchor tag A (80–100%) after 7 months; anchor tag B showed a retention rate of only 20% after 3 months. The fingerling tag had a retention rate of 27.5% after 12 months. The opercular tag had a retention rate of 44% after 20 days but fractured the opercular bone in many cases. Tag incisions and wounds persisted in some fish for the duration of the experiment.     

Detection efficiency of multiplexed Passive Integrated Transponder antennas is influenced by environmental conditions and fish swimming behaviour

Abstract –  The efficiency of a Passive Integrated Transponder (PIT)-tag detection system was tested during a 23-day experiment using a permanent digital video to record the passage of fish through multiplexed antennas. Coupling video to the PIT system allowed the detection of error sources and the correction of erroneous data. The efficiency of the detection system and its variation were investigated according to fish swimming speed, direction of movement and individual fish behaviour. Influence of time and environmental conditions on detection results were also checked. The PIT tag system was 96.7% efficient in detecting fish. Upstream movements were better detected (99.8%) than downstream movements (93.7%). Moreover, results showed that efficiency rate was not stable over the experiment; it was reduced on stormy days. Several sources of errors were identified such as sub-optimal orientation of the PIT tag relative to the antenna plane, the influence of fish swimming speed, individual fish behaviour and influence of environmental conditions.     

Tagging: on the use of passive integrated transponder (PIT) tags for the identification of fish

To determine the efficacy of passive integrated transponder (PIT) tags for marking rohu Labeo rohita (Ham.) in the selective breeding programme, a series of experiments has been carried out at the Central Institute of Freshwater Aquaculture (CIFA) under the Indo–Norwegian project of ‘Selective breeding of rohu’. Six groups of rohu fingerlings with weight ranging from 2 g to 20 g were tagged with PIT tags to determine a suitable size range for tagging. Fingerlings weighing 8–15 g were found to be quite suitable for tagging with a PIT tag. Recovery of the PIT tag depends upon the survival of tagged fish under field conditions. Rejection of the PIT tag by rohu was observed to be only 0.05%. Through effective management practice, the survival of tagged fish increased up to 95%, and thus tag loss was minimized.     

Effects of radio-transmitter antenna length on swimming performance of juvenile rainbow trout

Abstract –  Technological advances have lead to the production of micro radio-transmitters capable of being implanted in fish as small as c . 5 g. Although the actual tags are small, transmitters are equipped with long antennas that can increase drag and tangle in debris. We examined the effects of radio-transmitter antenna length on the swimming performance of juvenile rainbow trout, Oncorhynchus mykiss , ( N  = 156, mean mass = 34 g, mean fork length = 148 mm). Although we tested a variety of different antenna lengths up to a maximum of 300 mm, only the longest antenna significantly impaired swimming performance relative to control fish ( P  < 0.001). There was no difference in swimming performance between the sham (surgery, but no transmitter) and the control fish (handled, but no surgery), suggesting that the surgical procedure itself did not negatively affect the fish. Regression analysis, however, indicated that there was a significant decrease in swimming performance associated with increased antenna length ( R ² = 0.11, P  < 0.001). In addition, when held in laboratory tanks, fish with the three longest antennas (150, 225 and 300 mm) frequently became entangled with the standpipe. We suggest that researchers, under the guidance of the tag manufacturer, trim antennas to the shortest possible length required to detect fish in their specific study area. Antenna length is clearly an important issue for small fish, especially for species that inhabit complex habitats where antennas may become entangled, and where fish must attain speeds near limits of their swimming capacity.     

The Effect of PIT Tagging on Survival,Tag Retention,and Weight Gain in Fingerling White Bass

We tagged fingerling white bass, Morone chrysops, with passive integrated transponders (PIT) at two body locations (peritoneal cavity and dorsal musculature) and six weight classes to evaluate survival, tag retention, and weight gain during a 28-day experimental period. The probability of survival (as calculated by logistic regression) was >95% for fingerlings >19 g for both PC and DM. Retention of PIT tags varied between PC and DM tagged white bass in 6 g and 14 g fingerlings. The probability of tag retention was 100% in all sizes of fingerlings tagged PC, and >95% for fish >19 g tagged DM.     

Assessment of residency and movement of the endangered bullhead (Cottus gobio) in two Flemish rivers

Abstract –  Residency and movement of bullheads ( Cottus gobio ) were assessed by mark-recapture from November 2001 to June 2002 in two Flemish rivers [Steenputbeek (SPB), Laarse Beek (LB)]. Although the majority of the recaptured bullheads (SPB: 66%; LB: 55%) was found in their initial tagging site before the spawning season, some fish had covered distances between 10–100 m (mean: 17 ± 2 m) and 10–70 m (mean: 18 ± 7 m), respectively. During the spawning season, the proportion of fish that moved (SPB: 58%; LB: 75%) and the distances travelled (SPB: between 10 and 90 m, mean 26 ± 3 m; LB: between 30 and 260 m, mean 133 ± 3 m) were significantly larger. In addition, analysis of individual movement behaviour of multiple recaptured bullheads showed that some fish were either always resident or mobile, while others switched between both behaviours. In general, our results suggest that not all bullheads exhibit sedentary behaviour but that the populations under study consist of both stationary and mobile individuals.     

Laboratory experiment on survival,growth and tag retention following PIT injection into the body cavity of juvenile brown trout (Salmo trutta)

A laboratory study was conducted to assess the effect of PIT tagging on survival and growth of young-of-the-year brown trout (Salmo trutta) and evaluate PIT tag loss as a function of body size at tagging. Transponders (11.5 mm long and 2.1 mm in diameter) were injected into the peritoneal cavity of fish ranging from 41 to 70 mm fork length (FL) using hypodermic needles. A total of 145 tagged fish and 136 control fish of similar size were reared over 4 weeks. Logistic regressions show that survival rate reached 95% for fish ≥52 mm FL at tagging (with a tag retention rate >70%), and 99% for fish ≥57 mm FL (tag retention rate >80%). No significant effect of tagging on growth (fork length and weight) was detected at the end of the experiment. The specific growth rate varied markedly among PIT-tagged fish regardless of fork length, weight or tag-to-body-weight ratio at tagging. Results suggest that juvenile brown trout larger than 57 mm FL (tag-to-body weight ratio in water <3.4%) can be marked by injection of 11.5 mm PIT into the peritoneal cavity with negligible effects on survival and growth, but this leads to a relatively high tag rejection rate (up to 20%).     

Evaluation of two anaesthetic agents and the passive integrated transponder tagging system in Octopus vulgaris (Cuvier 1797)

Octopus vulgaris is a species of demand in the market with the potential to diversify European aquaculture. However, this species develops complex social interactions under culture conditions, which may have negative effects on its growth, survival and profitability. In order to understand its behaviour under such conditions, individual tagging systems allow a careful evaluation of biological parameters, such as growth and longevity. The present work describes a combined protocol (anaesthetic and tagging) for implanting subcutaneous passive integrated transponder tags (PIT). The effect of two anaesthetic agents in facilitating octopus handling is assessed: clove oil at 20–40–100 mg L^?1 and ethanol (96%) at 1–1.5–2%. The most suitable body location of PIT tags, its effect on growth and mortality, the addition of a stitch and the PIT retention rate after 2 months in floating cages were evaluated. It was concluded that immersion in seawater with 1.5% of ethanol at 22.3±0.5 °C is a suitable anaesthetic for this species. The results showed that the best‐selected PIT body location was the upper left arm III. No effect of the PIT tagging system was found on growth and survival when tagged and untagged octopuses were compared. It was observed after 2 months that the stitch did not induce an increase in the retention rate and 81–100% tag retention regardless of the dietary treatment.     

Comparison of pelvic fin rays, scales and otoliths for estimating age and growth of bull trout, Salvelinus confluentus

Abstract  The suitability of three anatomical structures to determine age and growth of bull trout, Salvelinus confluentus (Suckley), was assessed. Scales and pelvic fin rays collected from recaptured bull trout 96–265 mm TL were used to validate annulus formation and assess the accuracy and precision of back calculation. Ageing precision and agreement of assigned ages were compared among scales, fin rays and otoliths from bull trout 52–711 mm TL. Annulus formation was validated for 88% (14 of 16 fish) of recaptured bull trout using pelvic fin rays and 68% using scales (15 of 22 fish). Annulus formation in fin rays occurred between late April to early June, and the hyaline (non-growth) band began forming in late August. Back-calculated length was not significantly different from measured length at initial capture either for fin rays or scales ( P  ≥   0.19), and absolute percent error was 7.2 ± 1.2 (mean ± SE; n  =   14) for fin rays and 8.7 ± 1.9 ( n  =   15) for scales. Consistency of back-calculated lengths at age between tag and recapture samples for individual fish was similar for fin rays (mean absolute difference = 8.2% ± 0.9; n  =   33) and scales (9.4% ± 1.4; n  =   40). However, fin rays (87% precision) and otoliths (90%) provided notably higher ageing precision than scales (68%) and closer agreement of assigned ages, particularly for fish older than age 4. Pelvic fin rays appear to offer more accurate and precise age and growth determinations than scales and a non-lethal alternative to otoliths, but further work is needed to validate the accuracy and precision of ageing large, migratory bull trout.     

Effects of tagging on migration behaviour,survival and growth of hatchery‐reared Atlantic salmon smolts

The effects of four different tagging methods (PIT, anchor T‐tag, Carlin tag and dummy radio transmitter) on survival, behaviour and growth of Atlantic salmon smolts during their downstream migration were examined in semi‐natural circular channels during a natural migration period in spring. Survival of smolts was high and tagging wounds healed well in all tagging groups. Tag loss rates were generally low, being the highest (2.5%) in the dummy radio transmitter group. Total length and body mass of the tagged and untagged smolts did not differ at the end of the experiment. Migration activity of smolts generally showed similar patterns among the treatments. However, Carlin‐tagged smolts started their migration slightly later than the PIT‐tagged fish, and smolts tagged with Carlin tag or dummy radio transmitter showed less overall migration activity than fish with PIT tag.     

Ontogeny of anti-predator behavior in hatchery-reared jack mackerel Trachurus japonicus larvae and juveniles: patchiness formation, swimming capability, and interaction with jellyfish

ABSTRACT:   Laboratory rearing and behavioral observations of larval and juvenile jack mackerel Trachurus japonicus were conducted to elucidate their life-history traits with emphasis on the interaction with the moon jellyfish Aurelia aurita . Jack mackerel were raised from naturally spawned fertilized eggs and they attained 10.3 ± 0.7 (mean ± standard deviation) mm in body length (BL) by 30 days post hatching (dph) and 26.6 ± 1.8 mm BL at 48 dph raised at 19.3–25.0°C. Patchiness (dense aggregation) was confirmed from 5–16 dph (2.9–5.9 mm BL) during the day and from 9–48 dph (4.0–27 mm BL) at night. Cruise and burst swimming speeds were 1.5–1.9 BL/s and 16–24 BL/s, respectively, during larval and juvenile stages, in experimental tanks. Although escape performance from jellyfish was not different between the larvae of jack mackerel and chub mackerel Scomber japonicus , both species showed better survival compared to red sea bream Pagrus major larvae of a similar size. Although jack mackerel were slow in growth, their slow cruise swimming may reduce the chance of encountering predators and fast burst swimming may help escape from gelatinous predators.     

Tagging juvenile European whitefish (Coregonus lavaretus (L.)) with passive integrated transponders—Impact of fish size on growth performance and tag retention

The study examined the effect of PIT tagging and size on the growth, survival, food conversion, tag retention and wound healing in juvenile European whitefish. Three size classes of juvenile whitefish (class S—body weight (b.w.) approx. 4.0 g; class M—b.w. approx. 8.0 g; class L—b.w. approx. 13.6 g) were tagged with PIT implanted intraperitoneally (TROVAN^®, United Kingdom). These groups formed S‐P, M‐P and L‐P respectively. Fish from the control groups (groups S‐C, M‐C and L‐C) were not tagged. Whitefish from the tagged and control groups were reared for 28 days in recirculating aquaculture systems. Only in the fish from the smallest group (group S‐P) was tagging confirmed to have a negative impact on growth rate and survival, which, after 28 days, was 70% in comparison with 94.4% in group S‐C. The rate of wound healing in all whitefish groups was similar. After 28 days following PIT implantation, all wounds were healed. Short‐term PIT retention (28 days) for all the groups was > 90%, and no differences were noted among groups. In summary, it is recommended that whitefish be PIT‐tagged using the intraperitoneal method after they have attained a body weight > 8 g. Tagging smaller specimens of this species leads to higher mortality.     

Long‐term Effects of Passive Integrated Transponder Tagging on the Growth of Olive Flounder,Paralichthys olivaceus

The effects of passive integrated transponder (PIT) tagging on the growth and survival of olive flounder, Paralichthys olivaceus (initial average mass ± SD: 502 g ± 14.3), were examined for 8 mo. Tag readability in relation to implant position (eyed‐side muscle, blind‐side muscle, and peritoneal cavity) was also documented. The overall weight gain of fish tagged in the eyed‐side muscle (444 g) was significantly less than control and tagged fish in the blind‐side muscle and peritoneal cavity, which showed 470–488 g of weight gain (KW, P < 0.001, N= 78, df = 3). Specific growth rates (%/d) did not differ significantly (P > 0.05) among control, blind‐side muscle, and peritoneal cavity groups. No significant (P > 0.05) difference in survival rate was found between treatment and control. The readability of PIT tags in all implanted positions was 100%. The average time spent tagging at each position was less than 30 sec. These results show that PIT tagging of olive flounder weighing approximately 500 g in the blind‐side muscle and peritoneal cavity is feasible and reliable with fewer negative effects on growth than observed on the eyed‐side muscle site trial.     

Development of external and neutrally buoyant acoustic transmitters for juvenile salmon turbine passage evaluation

Fish can sustain injury or mortality when they pass through hydroelectric facilities. To develop a method to monitor the passage and survival of juvenile salmonids without bias through turbines within the Federal Columbia River Power System, we developed and fabricated two designs of neutrally buoyant transmitters: Type A (sutured to the dorsal musculature of the fish anterior to the dorsal fin) and Type B (two-part design attached with wire pushed through the dorsal musculature, ventral to the dorsal fin). To determine the efficacy of the two designs under non-turbine passage-related conditions, fish had one of the tags attached and were held for 14 days to determine any potential effects of the tags on growth, survival and tissue damage. We also evaluated the attachment method by monitoring tag retention. These two neutrally buoyant tag designs were compared to nontagged individuals and those surgically implanted with current Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters and passive integrated responder (PIT) tags. In addition, two suture materials (Monocryl and Vicryl Rapide) were tested for attachment of Type A tags. When compared with non-tagged individuals, fish tagged with Type A tags did not differ significantly with respect to growth or mortality over a 14-d holding period. However, fish tagged with Type B transmitters had lower growth rates than the nontagged controls or other tag treatments. The efficacy of two designs was also compared to nontagged individuals under shear exposure. Fish were exposed to a submerged, 6.35-cm-diameter water jet at velocities ranging from 3.0 to 12.2 m/s in a water flume to simulate turbine conditions within the Columbia River basin. Throughout the shear exposure study, no mortalities or tag loss were observed. There was also no significant difference in the rates of shear injury between untagged fish and fish tagged with Type A or Type B tags. When tissue damage was assessed for tagged individuals exposed to shear forces, those tagged with Type A tags showed lower rates and severity of injury when compared to Type B-tagged fish. Overall, Type A tags may be a viable tag design for juvenile Chinook salmon passing through hydropower facilities.     

Relationships between trout habitat use and woody debris in two southern New England streams

Abstract – In-stream habitat was measured and trout density was estimated in Merrick Brook (105 habitat units) and the Tankerhoosen River (135 habitat units), Connecticut to determine relationships between habitat use of brook trout Salvelinus fontinalis and brown trout Salmo trutta and woody debris. In each habitat unit, woody debris was inventoried, and length, width, depth, area, width : depth ratio and undercut bank area were estimated. Trout abundance was estimated by snorkeling. Multiple regression was used to test relationships between trout density and principal components describing habitat unit variables. In Merrick Brook, habitat unit size and shape explained most of the variability in density of brook trout (<130 and ≥130 mm) and brown trout (<150 mm) among habitat units, although principle components describing large woody debris or fine woody debris contributed significantly to variations in density of brook trout (≥130 mm) and brown trout (<150 and ≥150 mm). In the Tankerhoosen River, fine woody debris explained most of the variability in density of brook trout (<130 and ≥130 mm), followed by habitat unit size and shape. Both large woody debris and fine woody debris contributed significantly to variations in density of brown trout (≥150 mm). These results suggest that woody debris is an important component of wild trout habitat above that provided by habitat unit shape and size alone.     

Effect of intraperitoneal passive implantable transponder (PIT) tags on the growth and survival of juvenile snapper, Pagrus auratus (Bloch and Schneider)

Abstract. This study examined whether passive implantable transponder (PIT) tags could be used to mark individually juvenile snapper, Pagrus auratus (Bloch and Schneider), without affecting their growth. Fifty juvenile snapper (25 tagged and 25 untagged controls) were placed in each of four 2000–1 tanks. At the start of the experiment the snapper had a mean weight of 59 ± 18g (SD). After 70 days, the mean weight of all fish was 115 ± 31 g (SD) and there was no significant difference between the growth of tagged and untagged fish. Apparent tag loss ranged from 4 to 8%.     

Size-related changes in habitat selection by larval grayling (Thymallus thymallus L.)

Abstract  – In a medium-sized river in northern Finland, larval grayling shifted with growth from shallow habitats with slow velocities, fine substrata and abundant vegetation cover to deeper sites with swifter velocities, coarse substrata and sparse vegetation cover within 3 weeks. Small (17–21 mm) larvae preferred water depths 10–30 cm, substrata dominated by mud or sand (<2 mm), 10–70% vegetation cover and water velocities <10 cm · s⁻¹. Middle-sized (22–25 mm) larvae preferred 30–90 cm depths, sandy substrata, <40% vegetation cover and velocities <10 cm · s⁻¹. Large (26–31 mm) larvae preferred >50 cm depths, substrata dominated by sand or boulders, <20% vegetation cover and 10–50 cm · s⁻¹ velocities. The strict habitat requirements of the smallest larval group suggest that these habitats, in particular, are important to the early survival of grayling.     

Diet shift of larval and juvenile landlocked Ryukyu-ayu <Emphasis Type="Italic">Plecoglossus altivelis ryukyuensis</Emphasis> in the Fukuji Reservoir,Okinawa Island,Japan

ABSTRACT:   The diet shift of larval and juvenile Ryukyu-ayu Plecoglossus altivelis ryukyuensis was investigated for the landlocked population stocked in the Fukuji Reservoir, Okinawa Island. Gut contents of 274 specimens (5.1–31.4 mm in body length) including 31 yolk-sac larvae (5.7–8.0 mm) were examined. The diet of larval and juvenile landlocked P. a. ryukyuensis was mainly composed of zooplankton such as dinoflagellates, rotifers, copepods, and cladocerans. Feeding incidence was 48% in total and it gradually increased with growth. Diet analysis clearly demonstrated a diet shift during the larval and juvenile periods. For yolk-sac larvae and 5.0–19.9 mm fish, the diet was dominated by dinoflagellates Gymnodinium sp., and Peridinium sp., both numerically and by frequency, followed by rotifers that mainly consisted of Polyarthra spp. Diet breadth (Levin's standardized index B_A) diversified with growth, and feeding on copepods and cladocerans gradually increased in 10.0–14.9 mm fish. Diet overlap (Morisita's index: C) showed that diet drastically changed in 20.0–24.9 mm fish with a specialization on cladocerans Bosminopsis deitersi and Diaphanosoma brachyurum . This diet shift probably corresponded with an increase of feeding ability resulting from an enlargement of the mouth, increased swimming ability, and the development of sense organs.