The importance of passive integrated transponder (PIT) tags

in population monitoring

Kelle Holmes

University of Exeter, Penryn Campus 630030391

Keywords: Chelonia mydas, Caretta caretta, tag-loss, PIT, monitoring Word count: abstract: 137, main: 4527 59 references, 3 figures, 2 tables

Supervisor: Annette Broderick

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Abstract

In the study of life history traits, it is important to be able to re-identify individuals. Long-term

individual-based monitoring of green and loggerhead turtles at Alagadi, northern Cyprus is

providing fundamental and applied insights into marine turtle life histories. For both species,

tag loss probability for plastic flipper, titanium flipper, and passive integrated transponder

(PIT) tags was calculated. For both green and loggerhead turtles, tag loss probabilities were

greater having accounted for the use of PIT tags to help identify a female. This would have

resulted in over-estimation of green turtle recruitment by 44% and loggerhead recruitment

by 25%. The present study highlights the importance of PIT tag use in long term population

monitoring to reduce population estimate bias resulting from tag loss. Proficiency of tagging

procedures, double tagging and potential tag loss causes are also discussed.

Introduction

A basic tool for understanding and conserving wildlife populations is population modelling

(Nicholes and Williams, 2006). Credible development of population models needs accurate

and reliable reproductive and survival estimates. Population assessments can be made

difficult when individuals may have large ranges and be difficult to sample and re-identify

(Baily, 1951, Sedinger et al, 2008). These problems are particularly profound for marine

animals as they can remain submerged for long periods of time and move across thousands

of kilometres (Rasmussen et al. 2007). Estimating populations can be made easier when the

study species exhibits predictable migrations or nesting aggregations (for example harbour

seals (Thompson et al., 2005), white sharks (Jorgensen et al. 2009) and marine turtles

(Broderick et al., 1996)).

Monitoring programmes heavily rely on the ability to identify individuals over-time

(Balazs, 1999). The re-identification of individual animals can be achieved in a number of ways:

natural markings (Katona and Whitehead, 1981 and Kelly, 2001), branding (McMahon et al.,

2006), bands (Dugger et al., 2006), identification microchips (Gibbons and Andres, 2004;

Harper and Batzli, 1996 and Buhlmann and Tuberville, 1998), rings (Lakhani, 1987 and

Kenward et al., 2000), ear and flipper tags (Morley, 2002). Recognising individual markings is

often the most challenging way to re-identify an individual (Stevick et al., 2001). Therefore,

many population monitoring programs mark individuals using tags. Animals are often marked

with two tags to maximise the chance that upon recapture the individual will have at least one

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tag still attached (rather than presumed dead and lost to the study). The inability to recognise

a tag either through illegibility, damage or physical loss (hereafter termed tag loss) can

become a major confounding variable for re-identification experiments (Arnason and Mills,

1981). Population estimates derived from tag returns can often be inaccurate, owing to tag

loss errors (Arnason and Mills, 1981 and Stobo and Horne, 1994). Failure to consider tag loss

in any monitoring program will lead to over estimations of population abundance,

underestimations of survival and subsequent bias in data and further analyses. The

development of photo identification techniques for re-identification are becoming more

common amongst marine turtle research groups (Reisser et al., 2008, Schofield et al., 2008).

However, the most established method for marine turtle re-identification is through the use

of metal or plastic flipper tagging techniques alongside Passive Integrated Transponder

(hereafter PIT) tags. During a study on green turtles at Ascension Island, Mortimer and Carr

(1987) reported 78% tag loss and upper retention estimates of just six years. Previous studies

have attributed marine turtle tag loss to a variety of reasons. These include: tag position, tag

application, tag type, tag material, species of turtle and subsequent lifestyle differences

including the environment that the turtle is in (Reisser et al., 2008; Limpus, 1992; Balazs,

1982).

Loggerhead turtles (Caretta caretta) and Green turtles (Chelonia mydas) in the

Mediterranean migrate from their North African feeding grounds to on the beaches of Cyprus,

Turkey and Greece. A turtle that is new to the population is termed a neophyte. Female green

and loggerhead turtles do not breed every single year. The interesting period (termed

remigration) is variable due to fluctuating environmental factors and individual body condition

(Solow et al., 2002; Broderick et al., 2003). Females will lay multiple clutches inter-annually

(Stokes et al 2014). Turtle populations are vulnerable to many anthropogenic disturbances

(Snape et al., 2016; Nada and Casale, 2011; Godley et al., 1998) which have subsequently led

to their decline and both species are currently of conservation concern (Casale and Tucker,

2015 and Seminoff, 2004).In order to quantify these threats, we need to understand more

about their life history traits, of which there is still a lot unknown. At Alagadi, northern Cyprus,

a saturated tagging programme is used to monitor green and loggerhead females during the

nesting season. This is part of an on-going effort to understand how variations in their life

history traits impact on population dynamics, survival, growth and behavioural strategies. The

findings are then used to put in place effective management interventions for conservation.

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After twenty years of monitoring, long-term data sets are being generated. However, if valid,

reliable studies based on tag return data are to proceed, then the issue of tag loss needs to

be addressed.

The first objective of this study was to estimate the tag loss probabilities for different

tag types using the method as described by Limpus (1992). The second objective was to

investigate the ramifications of tag loss assumptions and to determine how lack of detection

could have affected tag loss estimates. The effect of double tagging and potential causes of

tag loss are also discussed.

Methods

The study was conducted on Alagadi beach, in Northern Cyprus where both green and

loggerhead turtles are found nesting in considerable numbers (Broderick and Godley, 1996).

Throughout the nesting season the 2km beach is closed to the public between 2000 and 0800

hours (+3hGMT) in order to minimise anthropogenic disturbance.

Tagging and Recapture of Turtles

Data were collected throughout the nesting seasons of 1992-2015. Patrols ran along the beach

from 21:00 to 06:00 hours (local time) each night between late May and mid-August with

monitoring ceasing after five days of no nesting activity (Broderick and Godley, 1996). Once a

female was observed laying, she was examined for existing tags. If the female had no tag, lost

one tag or a tag had become unreadable, then a new tag was attached. Females were tagged

whilst in the covering phase, immediately after completion of oviposition. Both green and

loggerhead females were tagged on the trailing edge of the fore-flippers in the thin skin

between the proximal second and third scales. PIT tags were injected under the skin in the

shoulder. Where possible females were given flipper tags on both fore-flippers and

occasionally in both shoulders to avoid the loss of the turtle ID (Björnsson et al., 2011). Flipper

tags used were self-piercing with self-locking ‘through the hole’ mechanism. They were

attached using the respective specific tag applicators as supplied by the tag manufacturer. No

local anaesthetic was used as the piercing procedure is instantaneous. From 1992 to 1999

green and loggerhead females were tagged with plastic flipper tags (Dalton Jumbotags® used

1992-1994, Dalton Supertag® used 1994-1999; Dalton Tags, UK). From 1999-2015 titanium

Stockbrands® (Australia) flipper tags were used - with the exception of 2014 where Inconel

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681/C tags where used (National Band & Tag Company, Kentucky, USA). PIT tags have been

used in addition to double-flipper tags since 1997. This ‘triple tagging’ method ensures

greater chance of identification from recaptures. Although in some cases females have

reacted to tagging by withdrawing their limbs or inhaling sharply, Broderick and Godley (1999)

have shown there to be no significant effects of tagging on the speed of descent, duration of

nesting behaviours or hatching success of clutches.

Estimation of Tag Loss

Tag loss was estimated and analysed separately for both green and loggerhead females. Tag

loss was estimated with respect to turtle species, tag age and tag type. Each tag was

considered independently and, for each tag, years since application (to the nearest whole

year), and presence or absence was recorded. Tag loss probability was calculated as per the

following Limpus (1992) equation: 𝑃𝑖 = 𝑏𝑖/(𝑎𝑖 + 𝑏𝑖) where, 𝑖 = number of years since tag

was applied (ie. tag age); 𝑎𝑖 = number of tags still attached to the recaptured turtle in year 𝑖

with a readable number; 𝑏𝑖 = number of tags lost/unreadable from recaptured turtles in year

𝑖; 𝑃𝑖 = the probability of a tag being lost or unreadable after 𝑖 years.

Results

For both species there were insufficient tag recoveries of Monel tags used in 2014 due to

remigration intervals and so these were excluded from all analysis. Estimates of tag loss

probabilities from recaptures up to an including 2015 for green and loggerhead are

summarised in Table 1.

Green Turtles (Chelonia mydas)

A total of 302 individually identifiable nesting green female turtles have been tagged at

Alagadi since 1992 and were included in this study. 38.74% (n=43) of neophytes nesting

between 1997 and 2010 did not re-migrate to this site in subsequent breeding seasons (2011-

2015 are not included here as these turtles may still return). Over eighteen years, there were

failed readings of the PIT tags of 31.85% (n=50) green turtles, of which 20.0% (n=10)

subsequently received an additional PIT tag. Of 307 titanium tags included in this study, 65%

(n=200) were lost before the turtle made its next migration to Alagadi. Of these tags, 93%

(n=186) were lost within six years, and 54% (n=107) were lost within three years.

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Table 1. Frequency distribution of tag loss for tags applied to Chelonia mydas and Caretta caretta in Alagadi, northern Cyprus, 1992-2015.

𝑎𝑖, number of tags still attached to recaptured turtle in year 𝑖 with a readable number; 𝑏𝑖, number of tags lost/unreadable from recaptured turtles in year 𝑖; CL, confidence limits

Chelonia mydas Caretta caretta

Tag Type Tag age (year 𝑖)

Tag Count Probability of loss ± 95% CL

Tag Count Probability of loss ± 95% CL 𝒂𝒊 𝒃𝒊 total 𝒂𝒊 𝒃𝒊 total

PIT 1 2 0 2 0∙000 ± 0∙000 12 1 13 0∙077 ± 0∙000 2 42 4 46 0∙087 ± 0∙058 41 5 46 0∙108 ± 0∙000 3 66 8 74 0∙108 ± 0∙051 36 4 40 0∙100 ± 0∙000 4 86 6 92 0∙065 ± 0∙036 23 5 28 0∙179 ± 0∙000 5 27 2 29 0∙068 ± 0∙065 29 4 33 0∙121 ± 0∙000 6 44 1 45 0∙022 ± 0∙031 17 1 18 0∙056 ± 0∙000 7 23 0 23 0∙000 ± 0∙000 10 0 10 0∙000 ± 0∙000 8 21 1 22 0∙045 ± 0∙062 6 0 6 0∙000 ± 0∙000 9 21 0 21 0∙000 ± 0∙000 13 0 13 0∙000 ± 0∙000 10 12 0 12 0∙000 ± 0∙000 5 0 5 0∙000 ± 0∙000 11 7 0 7 0∙000 ± 0∙000 4 0 4 0∙000 ± 0∙000 12 20 0 20 0∙000 ± 0∙000 9 0 9 0∙000 ± 0∙000 13 14 0 14 0∙000 ± 0∙000 1 0 1 0∙000 ± 0∙000 14 7 0 7 0∙000 ± 0∙000 2 0 2 0∙000 ± 0∙000 15 9 0 9 0∙000 ± 0∙000 16 16 0 16 0∙000 ± 0∙000 1 0 1 0∙000 ± 0∙000 17 5 1 5 0∙167 ± 0∙213 5 0 5 0∙000 ± 0∙000 18 2 0 2 0∙000 ± 0∙000

Plastic 1 5 1 6 0∙167 ± 0∙213 2 25 4 29 0∙138 ± 0∙008 21 7 28 0∙250 ± 0∙000 3 27 15 42 0∙357 ± 0∙011 13 3 16 0∙188 ± 0∙000 4 9 10 19 0∙526 ± 0∙026 11 4 15 0∙267 ± 0∙000 5 18 13 31 0∙419 ± 0∙015 10 8 18 0∙444 ± 0∙000 6 7 10 17 0∙588 ± 0∙028 6 3 9 0∙333 ± 0∙000 7 1 15 16 0∙938 ± 0∙007 2 1 3 0∙333 ± 0∙000 8 8 6 14 1∙400 ± 0∙034 0 2 2 1∙000 ± 0∙000 9 0 3 3 1∙000 ± 0∙000 0 5 5 1∙000 ± 0∙000 10 3 2 5 1∙000 ± 0∙094 2 3 5 0∙600 ± 0∙000 11 0 1 1 1∙000 ± 0∙000 12 0 6 6 1∙000 ± 0∙000 1 0 1 0∙000 ± 0∙000 13 0 3 3 1∙000 ± 0∙000 0 1 1 1∙000 ± 0∙000 14 0 2 2 1∙000 ± 0∙000 15 16 17 0 1 1 1∙000 ± 0∙000 18 0 1 1 1∙000 ± 0∙000

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Table 1. continued

Titanium 1 1 2 3 0∙667 ± 0∙145 5 1 6 0∙167 ± 0∙213 2 19 39 58 0∙672 ± 0∙007 21 7 28 0∙250 ± 0∙115 3 44 63 107 0∙589 ± 0∙004 13 3 16 0∙188 ± 0∙137 4 31 81 112 0∙723 ± 0∙004 11 4 15 0∙267 ± 0∙160 5 11 12 23 0∙522 ± 0∙021 10 8 18 0∙444 ± 0∙164 6 15 8 23 0∙348 ± 0∙019 6 3 9 0∙333 ± 0∙220 7 7 5 12 0∙417 ± 0∙040 2 1 3 0∙333 ± 0∙381 8 6 10 16 0∙625 ± 0∙029 0 2 2 1∙000 ± 0∙000 9 5 9 14 0∙643 ± 0∙032 0 5 5 1∙000 ± 0∙000 10 3 2 5 0∙400 ± 0∙094 2 3 5 0∙600 ± 0∙307 11 12 2 4 6 0∙667 ± 0∙073 1 0 1 0∙000 ± 0∙000 13 1 0 1 0∙000 ± 0∙000 1 0 1 0∙000 ± 0∙000 14 1 1 2 0∙500 ± 0∙245 1 1 2 0∙500 ± 0∙000

Without the use of PIT tags Plastic 1 5 1 6 0∙167 ± 0∙213 2 25 3 28 0∙107 ± 0∙082 20 4 24 0∙167 ± 0∙107 3 27 6 33 0∙182 ± 0∙094 13 2 15 0∙133 ± 0∙123 4 9 2 11 0∙182 ± 0∙163 11 4 15 0∙267 ± 0∙160 5 18 7 25 0∙280 ± 0∙126 10 6 16 0∙375 ± 0∙170 6 6 4 10 0∙400 ± 0∙617 6 1 7 0∙143 ± 0∙185 7 1 8 9 0∙889 ± 0∙147 2 1 3 0∙333 ± 0∙381 8 8 1 9 0∙111 ± 0∙147 0 1 1 1∙000 ± 0∙000 9 0 2 2 1∙000 ± 0∙000 0 3 3 1∙000 ± 0∙000 10 3 0 3 0∙000 ± 0∙000 2 3 5 0∙600 ± 0∙307 11 12 0 4 4 1∙000 ± 0∙000 1 0 1 0∙000 ± 0∙000 13 0 1 1 1∙000 ± 0∙000 Titanium 1 1 0 1 0∙000 ± 0∙000 9 1 10 0∙100 ± 0∙133 2 16 12 28 0∙429 ± 0∙131 26 9 35 0∙011 ± 0∙103 3 39 16 55 0∙291 ± 0∙086 23 10 33 0∙013 ± 0∙112 4 29 20 49 0∙408 ± 0∙098 16 4 20 0∙016 ± 0∙250 5 11 3 14 0∙214 ± 0∙154 7 5 12 0∙040 ± 0∙199 6 14 6 20 0∙300 ± 0∙143 3 2 5 0∙094 ± 0∙307 7 7 1 8 0∙125 ± 0∙164 6 1 7 0∙034 ± 0∙185 8 5 0 5 0∙000 ± 0∙000 3 1 4 0∙092 ± 0∙303 9 5 2 7 0∙286 ± 0∙240 2 0 2 0∙000 ± 0∙000 10 3 1 4 0∙250 ± 0∙303 1 0 1 0∙000 ± 0∙000 11 2 0 2 0∙000 ± 0∙000 12 2 2 4 0∙500 ± 0∙350 1 0 1 0∙000 ± 0∙000 13 1 0 1 0∙000 ± 0∙000 14 1 0 1 0∙000 ± 0∙000 1 1 2 0∙245 ± 0∙495

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PIT tag loss was considerably less than that of both flipper tag types (mean annual

probability of loss = 0.0313, and for combined flipper tags = 0.609). The greatest flipper tag

loss was associated with plastic flipper tags (mean annual probability of loss = 0.720, titanium

tag mean annual probability of loss = 0.521). All flipper tag loss probability estimates for green

were greater having accounted for the use of PIT tags to help identify a female without flipper

tags (Figure 1). Without accounting for the use of PIT tags to help identify a female, mean

annual probability of plastic tag loss was 0.415, for titanium tags 0.216 and for both flipper

tag types combined 0.244.

(a) PIT

(b) Flipper

(c) Plastic

(d) Titanium

Figure 1: Probability of tag loss for Chelonia mydas in Alagadi, Northern Cyprus. a) PIT tags b) Flipper tags (plastic and titanium combined) c) Plastic tags d) Titanium tags. Solid circles represent tag loss estimates having accounted for the use of PIT tags to help identify a female. Open circles represent tag loss estimates without accounting for the use of PIT tags

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The results for the number of returning green turtles that lost both flipper tags and were

identified by PIT tag only are summarised in Table 2 and Figure 2a (1997-2008 are not included

here to ensure that all potential returning turtles would had been given a PIT tag). On average

44.16% of green turtles were identified by PIT tag alone as a result of having lost both of their

flipper tags. Therefore, without the use of PIT tags, flipper tag loss would result in a 44.16%

over-estimation of green turtle neophytes.

Loggerhead Turtles (Caretta caretta)

A total of 342 individually identifiable nesting female loggerhead have been tagged at Alagadi

since 1992 and were included in this study. 72.69% (n=157) of neophytes nesting between

1997 and 2010 did not re-migrate to this site in subsequent breeding seasons (2011-2015 are

not included here as these neophytes may still return). Over eighteen years, there were failed

readings of the PIT tags of 30.56% (n=44) loggerhead turtles, 31.82% (n=14) of which

subsequently received an additional PIT tag. Of 134 titanium tags included in this study, 50%

(n=68) were lost before the turtle made its next migration to Alagadi. Of these tags, 99%

(n=67) were lost within six years, and 74% (n=50) were lost within three years.

PIT tag loss was considerably less than that of both flipper tag types (mean annual

probability of loss = 0.040 and for combined flipper tags = 0.433). The greatest flipper tag loss

was associated with plastic flipper tags (mean annual probability of loss = 0.466, titanium tag

Table 2. Number of returning Chelonia mydas and Caretta caretta that have lost both flipper tags and were identified by PIT tag only

x, number of turtles identified by PIT tag only (i.e. had no flipper tags); r, total number of turtles identified as ‘returns’ by flipper tags and/or PIT tags; n, number of turtles

identified as neophytes due to the absence of both PIT and flipper tags; %, percent of returning turtles hat would have been incorrectly identified as neophytes if not for the

use of PIT tags.

Chelonia mydas Caretta caretta Year x r n total % x r n total %

2009 10 18 22 41 55∙56 2 11 21 34 15∙38 2010 1 12 15 27 08∙33 0 3 16 19 00∙00 2011 7 20 32 54 35∙00 4 5 13 22 44∙44 2012 10 14 9 23 71∙43 0 5 14 20 00∙00 2013 7 26 61 86 26∙92 2 6 35 41 25∙00 2014 19 28 31 59 67∙86 1 4 28 35 20∙00 2015 11 25 36 61 44∙00 4 2 20 26 66∙67

Average % (mean) 44∙16 24∙50

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mean annual probability of loss = 0.331). All flipper tag loss probability estimates for

loggerheads were greater having accounted for the use of PIT tags to help identify a female

without flipper tags (Figure 3). Without accounting for the use of PIT tags to help identify a

female, mean annual probability of plastic tag loss was 0.432, for titanium tags 0.198 and for

both flipper tag types combined 0.333.

The results for the number of returning loggerhead turtles that lost both flipper tags and

were identified by PIT tag only are summarised in Table 2 and Figure 2b (1997-2008 are not

included here to ensure that all potential returning turtles had been given a PIT tag). On

average 24.50% of loggerhead turtles were identified by PIT tag alone as a result of having lost

both of their flipper tags. Therefore, without the use of PIT tags, flipper tag loss would result

in a 24.50% over-estimation of loggerhead turtle neophytes.

For plastic tags, species did not significantly contribute to tag loss (R2=0.09, P>0.05). For

titanium tags species contributed significantly to tag loss (R2=0.28, P<0.01) with loggerhead

having lower tag loss estimates than green. Species contributed significantly to PIT tag loss

(R2=0.22, P<0.05) with green having much lower tag loss estimates than loggerhead.

(a) Chelonia mydas (b) Caretta caretta

Figure 2: The number of returning a) green and b) loggerhead turtles identified using PIT tags only having lost both flipper tags. turtles identified as a neophyte due to the absence of flipper tags a PIT tags, turtles identified using PIT tags and flipper tags, turtles identified using PIT tag only

0

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2009 2010 2011 2012 2013 2014 2015

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2009 2010 2011 2012 2013 2014 2015

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(a) PIT

(b) Flipper

(c) Plastic

(d) Titanium

Figure 3: Probability of tag loss for Caretta caretta in Alagadi, Northern Cyprus. a) PIT tags b) Flipper tags (plastic and titanium combined) c) Plastic tags d) Titanium tags. Solid circles represent tag loss estimates having accounted for the use of PIT tags to help identify a female. Open circles represent tag loss estimates without accounting for the use of PIT tags

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Discussion

Variation between Tag Types

Results from the present study are evidence of strong differences in the effect of tag type on

the probability of tag loss (Figure 1 and Figure 3).

For both species, the greatest tag loss was associated with plastic flipper tags. Plastic

tags do not suffer from corrosion and, due to their locking mechanisms do not often fall out.

The most common reason for plastic flipper tag loss is that after five to six years, the tags are

deemed illegible. This means the turtle is no longer identifiable by this tag and would need

to be removed and replaced. For green turtles, the average duration of an attached, legible

plastic tag was six years and for loggerhead turtles five years. As remigration intervals are up

to six years for both green and loggerhead turtles (Stokes et al., 2014), it is unlikely that a

female would be recaptured on its next migration with both tags still legible. This will

drastically reduce the chance of successful re-identification in a long-term study. For

population trends to be detected, a minimum of three data points are required. Parmenter

(2003) reported plastic tag failures in flatback turtles (Natator depressus) of up to 80% within

the first three years of application. Due to the remigration intervals, a marine turtle tagging

programme would need to run for ten to fifteen years before it is possible to detect trends in

abundance which means plastic tag use would be inappropriate. Plastic tags have the

advantage of colour coding. By using a different colour for each tagging site, it is possible to

identify the origin on the individual without it having to be captured. This is particularly useful

when projects are working with fishermen to determine by-catch risk, or to gain re-sightings

of the tags by the public or other projects that do not have a PIT tag scanner. However, it has

been documented that plastic tags may increase the probability of a turtle becoming

entangled in fishing nets (Nichols et al., 1998). This has been supported by interviews with

local fishermen and an aquarium study that showed only tagged individuals were unable to

escape from entanglement in a net (Nichols et al., 1998). In sea turtle research, the use of

plastic tags should be limited to short-term studies on resident marine turtle populations and

are not necessarily fit for use in long-term tag return studies.

Titanium flipper tags had lower tag loss estimates than plastic flipper tags (Table 1).

Difference in species contributed to the variation in titanium tag loss rates between

loggerhead and green. For green, there was a significant decrease in titanium tag loss with

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increasing tag age. This reflects results by Rivalan et al. (2005) which showed metal tag loss

probabilities for leatherbacks were initially high for the first few years after tagging, followed

by increasing retention rates over time. For loggerhead, there was no significant trend

between increasing tag age and probability of loss. This may have been affected by the lack of

remigrations by new breeders to the population resulting in a lower number of loggerhead

recaptures than green (Tucker, 2010). Titanium flipper tags are highly resistant to corrosion -

at least seven years with no corrosive damage (Limpus, 1992), and there have been few

observations at Alagadi of tags being damaged or lost as a result of corrosion. The non-toxic

properties of titanium tags can mean that barnacles form on the tags. This increases the

overall size and weight of the tag resulting in an increased probability of loss. In some cases,

barnacles cannot be easily removed and may deem the tag unreadable for a considerable

length of time. The main cause for titanium tag loss is likely to come from the tags self-locking

‘through the hole’ mechanism. Due to the lack of proficiency of inexperienced volunteers, or

those with a limited amount of strength, the piercing point is not always fully bent into the

lock of the tag. Greater titanium tag loss has previously been associated with loggerhead and

green at nesting beaches over feeding grounds (Limpus, 1992). Due to the vigorous digging

actions of females whilst nesting and multiple nesting attempts, it is most likely that

improperly attached tags will be lost within the first few years revealing initially high rates of

tag loss (Figure 1c and Figure 3c). This issue can be avoided by ensuring, for all tags, that the

piercing point has locked fully into place with the respective specific tag applicators. If the tag

is still not in fully locked, then pliers should be used to complete the procedure (Balazs, 1982).

As expected, for both species PIT tags had the highest retention rates of all tag types

and results show that we are far off reaching their maximum lifespan limits (Figure 1a, Figure

3a). As PIT tags are internal, they are not at risk to abrasion or corrosion. As with plastic dart

tags used in many other marine species (Kirkwood, 1981), PIT tags can become so firmly

imbedded and over grown by tissue, that as time passes the probability of loss becomes closer

to zero (Rivalan et al., 2005). One of the drawbacks for only using PIT tags to monitor turtle

populations is that fishermen are unable to detect and observe PIT tags on turtles they catch

– that is unless they have been provided with a universal PIT tag scanner. As PIT tags are known

to be permanent marking tags (Gibbons and Andres, 2004), it would be reasonable to

attribute low levels of PIT tag loss to faulty application rather than physical loss. PIT tag loss

could also be associated with failure to detect the tag – be this from failure of the tag itself

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(Wyneken et al. 2010) or by inexperienced volunteers on patrol failing to detect the PIT tag

and replacing with a new tag. For 32% of green turtles and 31% of loggerhead turtles there

was a failure to read their PIT tag. Some of these failures resulted in the turtle being given a

new PIT tag (20% of greens and 32% of loggerheads). One female loggerhead was given four

new PIT tags over the course of the study as the previous PIT tags were not detected or had

failed to have been read. In recent years, all five PIT tags have been detected and read for this

individual showing that all the tags are still in full working order. In a study on hawksbill turtles,

van Dam and Diez (1999) found a 15% failure rate in the ability to detect PIT tags over 5years

showing that the results from this study are not negligible. The variation between the PIT

tagging proficiency of volunteers suggests that further efforts need to be made to standardise

training and tagging procedures (Shaughnessy, 1994).

PIT Tag Use

Tag loss estimates have been enhanced over the years by the use of permanent tagging

methods. In the present study, without the use of PIT tags, calculated estimates for flipper tag

loss for both green and loggerhead would be considerably lower (Table 1, Figure 1(b-d) and

Figure 3(b-d)). This was most apparent in green turtles (Figure 1) which suggests that almost

50% of all green turtle recaptures would result in incorrect neophyte identification (rather

than a returning turtle who has lost both her flipper tags).

Estimates of tag loss rates using permanent tagging methods are essential to reducing

bias in parameter estimates from population models. The use of PIT tags in Alagadi reduces

the uncertainty of incorrect neophyte identification (McDonald & Dutton, 1996). Without the

use of PIT tags, green neophyte numbers (2009-2015) would have been over estimate by

44.16% for green turtles and 24.50% for loggerhead turtles. Rising numbers of neophytes

within the population is indicative of population growth (Richardson et al. 2006). Results from

this study outline a vital question that all recapture projects must consider; if tag loss is being

underestimated, how much is recruitment and population size being overestimated? This

means that an over-estimation of neophytes number would result in an over-estimation of

population number (Stobo and Horne, 1994) leading to false assumptions regarding

population growth of loggerhead and green turtles at Alagadi. Survival estimates could

therefore also be biased as among capture-mark recapture models because an individual that

has lost its tags is no longer recognisable and so is indistinguishable from dead individuals. If

14

such bias is not detected and corrected for, any data collect for population monitoring will be

unreliable and invalid and we would see much larger recruitment estimates and

underestimation of survival for many populations. For example, the estimated annual flipper

tag loss rate calculated during a study on Californian Sea Otters (Enhydra lutris), led to

inaccurate and underestimated survival rates when data was derived from observations of

tagged individuals (Siniff and Ralls, 1991). Conservation efforts derived from such data may

not be relevant, or, at the very least, not as effective as they could be. For other marine turtle

projects, earlier estimates based solely on flipper tag returns should, where possible, be

revisited using permanent tagging methods in order to assess the accuracy of their tag loss

estimates. This will allow them to correct for any bias in their population monitoring data.

Double Tagging

Double tagging began as a way for monitoring projects to increase the chance that at least

one tag would remain on the turtle (Henwood, 1986). Tag loss is most often quantified using

double-tagging experiments that consist of releasing and monitoring groups of double tagged

animals and observing the proportion of animals that are recaptured with one or both tags

present (González-Vicente, 2012; Henry and Jarne, 2007; Dicken, 2006). This usually assumes

that the probability of losing one tag is independent of losing the other and so tag loss can be

estimated using animals that have lost one tag. There is a continuing body of evidence

showing that the assumption of independent tag loss is flawed (Schwarz et al., 2012; Rotella

and Hines, 2005; Rivalan et al., 2005). Using permanent markers, researchers are able to

determine the rate of loss for the second tag, whilst still being able to identify the individual.

A study on black bears using tattoos as a permanent marker found that the probability of a

male losing a second ear tag was greater if the first ear tag had already been lost (Diefenbach

and Alt, 1998). This had resulted in 6% bias for previously calculated annual survival estimates.

A more recent study on elephant seals found that there was 28% greater likelihood of an

individual losing its second flipper tag after the first tag had been lost (McMahon and White,

2009). In other words, if an animal is given two tags of the same nature (e.g. two flipper tags,

or two ear tags), it is more likely to lose both of its tags than it is to lose just one. At this point,

the extent to which this has affected the estimates for tag loss calculated in this study is

unknown, but should and will be addressed in future studies at Alagadi.

15

Between Species Variation

Sea turtles display obligate skipped breeding behaviour and lay a variable number of clutches

every few years. During inter-breeding periods they accumulate energy needed for

reproductive migrations and may only breed when their body condition and environmental

conditions reach a threshold value (Solow et al., 2002). Following tagging, 72.69% of

loggerhead and 38.74% of green turtles did not re-migrate to Alagadi in subsequent breeding

seasons. This suggests that green turtles are more faithful to their nesting beaches than

loggerheads (Phillips et al., 2014; Mortimer and Portier, 1989). A satellite telemetry study in

Florida showed that re-migrant loggerheads had higher site fidelity, compared to new

breeders (Tucker, 2010). This would suggest that the likelihood of recapturing a green turtle

after tagging is higher than the likelihood of recapturing a loggerhead turtle after tagging. This

could reflect some of the differences seen in the tag loss probability estimates for this study.

For example, there was a 0.244 difference in the mean probability of flipper tag loss with and

without the use of PIT tags for Green. For Loggerhead, this difference was much lower (0.100).

It would not be unreasonable to suggest that if more loggerhead neophytes did return, then

we would see even more accurate estimations for tag loss probabilities.

Other Tag Loss Concerns

Tag loss can result from a diverse range of causes. Flipper tags can be bitten by attendant

males biting at the flippers of mounted males during courtship (Limpus, 1992; Balazs, 1982).

If the tag is bent or squeezed against the flipper, this could lead to tissue degeneration

contributing to an increased probability of loss. In order to reduce the probability of tags being

lost for this reason, studies should use the smallest tags practical.

There have been many studies documenting the effects of tags on drag and

hydrodynamic efficiency in marine vertebrates (Serafy et al., 1995; Hazekamp et al., 2009). In

a study on penguins, the effect on drag caused by flipper bands resulted in higher energy

expenditure whilst individuals were in the water (Le Maho et al., 2011). This led to lower

foraging efficiency resulting in longer foraging trips and, ultimately, lower survival and

breeding success (Le Maho et al., 2011). No studies on the flipper tags used in this study have

found such effects on the hydrodynamics of green or loggerhead sea turtles. However,

biofouling, barnacles, debris and anthropogenic waste is known to sometimes attach to the

flipper tags of turtles, particularly when they have not been attached correctly. This increases

16

the weight and overall size of the tag and will contribute to an increase in drag. This will also

have serious effects on the turtle’s risk of entrapment and entanglement.

Marine turtle monitoring programmes must be cost effective in order to sustain data

collection over long periods of time. This will ensure they have enough data to draw accurate

estimations of populations and draw meaningful conclusions from studies. Variable funding

makes it difficult to ensure stability for these projects and so they should be based upon a set

of robust, inexpensive measurements that can be consistent long term (Lovett et al., 2007).

The cost of tags should be considered. Titanium flipper tags cost substantially less than PIT

tags (approximately US$2.20 per tag and $8.00 respectively). It is therefore important that

monitoring programmes consider the value of tags types based on the data that will be

obtained as well as the actual cost (Morely, 2002).

To conclude, tag loss can have profound effects within a population monitoring program. If

not appropriately assessed, tag loss errors will lead to over-estimation of population levels

and underestimation of survival rates. The use of permanent marking methods (such as PIT

tags) are invaluable in producing accurate estimations of tag loss. It is recommended that all

population monitoring programs undertake an assessment of tag loss alongside other data

collection to reduce any bias that may occur. A continued effort to develop and refine tag

types and tagging techniques across all species is important in reducing tag loss thus reducing

cost and increasing the quality of data collected.

Acknowledgements

Many thanks to my supervisor Annette Broderick. I would also like to thank the Marine Turtle Conservation Project field teams 1992-2015.

17

References

Arnason, A.N., and Mills, K.H. (1981). Bias and Loss of Precision Due to Tag

Loss in Jolly–Seber Estimates for Mark–Recapture Experiments. Can. J. Fish. Aquat..

Sci., 38, 1077–1095.

Balazs, G. (1999). Factors to consider in the tagging of sea turtles. Research and

management Techniques for the Conservation of Sea Turtles. IUCN/SSC Mar. Turtle

Spec. Group Publ., 4, 101–114.

Balazs, G.H. (1982). Factors Affecting the Retention of Metal Tags on Sea turtles. Marine

Turtle News., 20, 11–14.

Björnsson, B., Karlsson, H., Thorsteinsson, V., and Solmundsson, J. (2011). Should all fish in

mark–recapture experiments be double-tagged? Lessons learned from tagging

coastal cod (Gadus morhua). ICES J. Mar. Sci.,

Broderick, A.C., and Godley, B.J. (1996). Population and nesting ecology of the Green Turtle,

Chelonia mydas, and the Loggerhead Turtle, Caretta caretta, in northern Cyprus.

Zool. Mid. East., 13, 27–46.

Broderick, A.C., and Godley, B.J. (1999). Effect of tagging marine turtles on nesting

behaviour and reproductive success. Anim. Behav., 58, 587–591.

Broderick, A.C., Glen, F., Godley, B.J., and Hays, G.C. (2003). Variation in reproductive output

of marine turtles. J. Mar. Biol. Ecol., 288, 95–109.

Buhlmann, K., and Tuberville, T. (1998). Use of passive integrated transponder (PIT) tags for

marking small freshwater turtles. Chelonian Conserv. Biol., 3, 102–104.

Casale, P. and Tucker, A.D. (2015). Caretta caretta. The IUCN Red List of Threatened Species

2015

van Dam, R.P., and Diez, C.E. (1999). Differential tag retention in Caribbean hawksbill turtles.

Chelonian Conserv Biol., 3, 225–229.

Dicken, M.L., Booth, A.J., and Smale, M.J. (2006). Preliminary observations of tag shedding,

tag reporting, tag wounds, and tag biofouling for raggedtooth sharks (Carcharias

taurus) tagged off the east coast of South Africa. ICES J. Mar. Sci., 63, 1640–1648.

Diefenbach, D.R., and Alt, G.L. (1998). Modelling and Evaluation of Ear Tag Loss in Black

Bears. J. Wildlife Manage., 62, 1292–1300.

Dugger, K.M., Ballard, G., Ainley, D.G., and Barton, K.J. (2006). Effects of flipper bands on

foraging behavior and survival of adélie penguins (Pygoscelis adeliae). The Auk, 123,

858–869.

Gibbons, W.J., and Andrews, K.M. (2004). PIT Tagging: Simple Technology at Its Best.

BioScience 54, 447–454.

Godley, B.J., Gücü, A.C., Broderick, A.C., Furness, R.W., and Solomon, S.E. (1998). Interaction

between marine turtles and artisanal fisheries in the eastern Mediterranean: a

probable cause for concern? Zool. Mid. East., 16, 49–64.

González-Vicente, L., Díaz, D., Mallol, S., and Goñi, R. (2012). Tag loss in the lobster Palinurus

elephas (Fabricius, 1787) and implications for population assessment with capture-

mark-recapture methods. Fish. Res., 129–130, 1–7.

Harper, S.J., and Batzli, G.O. (1996). Monitoring Use of Runways by Voles with Passive

18

Integrated Transponders. J. Mammal., 77, 364–369.

Hazekamp, A.H., Mayer, R., and Osinga, N. (2009). Flow simulation along a seal: the

impact of an external device. European J. Wildlife Res., 56, 131–140.

Henry, P.Y., and Jarne, P. (2007). Marking hard-shelled gastropods: tag loss, impact on life-

history traits, and perspectives in biology. Inver. Biol., 126, 138–153.

Henwood, T.A. (1986). Losses of Monel Flipper Tags from Loggerhead Sea Turtles, Caretta

caretta. J. Herpetol., 20, 276–279.

Jorgensen, S.J., Reeb, C.A., Chapple, T.K., Anderson, S., Perle, C., Van Sommeran, S.R., Fritz-

Cope, C., Brown, A.C., Klimley, A.P., and Block, B.A. (2009). Philopatry and migration

of Pacific white sharks. P. Roy. Soc.Lond. B: Biol. Sci.

Katona, S.K., and Whitehead, H.P. (1981). Identifying Humpback Whales using their natural

markings. Polar Rec. 20, 439–444.

Kelly, M.J. (2001). Computer-aided photograph matching in studies using individual

identification: an example from serengeti cheetahs. J. Mammal., 82, 440–449.

Kenward, R.E., Walls, S.S., Hodder, K.H., Pahkala, M., Freeman, S.N., and Simpson, V.R.

(2000). The prevalence of non-breeders in raptor populations: evidence from rings,

radio-tags and transect surveys. Oikos, 91, 271–279.

Kirkwood, G.P. (1981). Generalized models for the estimation of rates of tag shedding by

southern bluefin tuna (Thunnus maccoyii). J. Conseil., 39, 256–260.

Lakhani, K.H. (1987). Efficient Estimation of Age-Specific Survival Rates from Ring Recovery

Data of Birds Ringed as Young, Augmented by Field Information. J. Anim. Ecol. 56,

969–987.

Le Maho, Y., Saraux, C., Durant, J.M., Viblanc, V.A., Gauthier-Clerc, M., Yoccoz, N.G., et al.

(2011). An ethical issue in biodiversity science: The monitoring of penguins with

flipper bands. CR. Biol., 334, 378–384.

Limpus, C.J. (1992). Estimation of Tag Loss in Turtle Research. Wildl. Res. 19, 457–469.

Lovett, G.M., Burns, D.A., Driscoll, C.T., Jenkins, J.C., Mitchell, M.J., Rustad, L., et al. (2007).

Who needs environmental monitoring? Front. Ecol. Environ., 5, 253–260.

McDonald, D., and Dutton, P. (1996). Use of PIT Tags and Photoidentification to Revise

Remigration Estimates of Leatherback Turtles (Dermochelys coriacea) Nesting in St.

roix, U.S. Virgin Islands, 1979-1995. Chelonian Conserv. Biol. 2, 148–152.

McMahon, C.R., and White, G.C. (2009). Tag loss probabilities are not independent:

Assessing and quantifying the assumption of independent tag transition probabilities

from direct observations. J. Exp. Mar. Biol. Ecol., 372, 36–42.

Mcmahon, C.R., Burton, H.R., Hoff, J.V.D., Woods, R., and Bradshaw, C.J.A. (2006). Assessing

Hot-Iron and Cryo-Branding for Permanently Marking Southern Elephant Seals. J.

Wildlife Man., 70, 1484–1489.

Morley, C.G. (2002). Evaluating the performance of PIT tags and ear tags in a capture-

recapture experiment. New Zeal. J. Zool., 29, 143–148.

Mortimer, J.A., and Carr, A. (1987). Reproduction and Migrations of the Ascension Island

Green Turtle (Chelonia mydas). Copeia, 1987, 103–113.

Mortimer, J.A., and Portier, K.M. (1989). Reproductive Homing and Internesting Behavior of

19

the Green Turtle (Chelonia mydas) at Ascension Island, South Atlantic Ocean.

Copeia, 1989, 962–977.

Nada, M., and Casale, P. (2011). Sea turtle bycatch and consumption in Egypt threatens

Mediterranean turtle populations. Oryx 45, 143–149.

Nichols, J.D., and Williams, B.K. (2006). Monitoring for conservation. Trends Ecol. Evol., 21,

68–673.

Nichols, W.J., Seminoff, J.., and Resindiz, A. (1998). Plastic “Roto-tags” may be linked to sea

turtle bycatch. Mar. Turtle News. 79, 20–21.

Parmenter, C.J. (2003). Plastic flipper tags are inadequate for long-term identification of the

flatback sea turtle (Natator depressus). Wildl. Res. 30, 519–521.

Phillips, K.F., Mansfield, K.L., Die, D.J., and Addison, D.S. (2014). Survival and remigration

probabilities for loggerhead turtles (Caretta caretta) nesting in the eastern Gulf of

Mexico. Mar. Biol., 161, 863–870.

Rasmussen, K., Palacios, D.M., Calambokidis, J., Saborío, M.T., Dalla Rosa, L., et al. (2007).

Southern Hemisphere humpback whales wintering off Central America: insights from

water temperature into the longest mammalian migration. Biol. Lett., 3, 302–305.

Reisser, J., Proietti, M., and Kinas, P. (2008). Photographic identification of sea turtles:

method description and validation, with an estimation of tag loss. Endang Species

Res., 5, 73–82.

Richardson, J.I., Hall, D.B., Mason, P.A., Andrews, K.M., Bjorkland, R., Cai, Y., et al. (2006).

Eighteen years of saturation tagging data reveal a significant increase in nesting

hawksbill sea turtles (Eretmochelys imbricata) on Long Island, Antigua. Anim.

Conserv., 9, 302–307.

Rivalan, P., Godfrey, M.H., Prévot-Julliard, A.-C., Girondot, M., and Lubow (2005). Maximum

Likelihood Estimates Of Tag Loss In Leatherback Sea Turtles. J. Wildlife Manage., 69,

540–548.

Schofield, G., Katselidis, K.A., Dimopoulos, P., and Pantis, J.D. (2008). Investigating the

viability of photo-identification as an objective tool to study endangered sea turtle

populations. J. Exp. Mar. Biol. Ecol., 360, 103–108.

Schwarz, L.K., Hindell, M.A., McMahon, C.R., and Costa, D.P. (2012). The implications of

assuming independent tag loss in southern elephant seals. Ecosphere, 3, 1–11.

Sedinger, J.S., Chelgren, N.D., Ward, D.H., and Lindberg, M.S. (2008). Fidelity and breeding

probability related to population density and individual quality in black brent geese

(Branta bernicla nigricans). J. Anim. Ecol., 77, 702–712.

Seminoff, J.A. (Southwest Fisheries Science Center, U.S.). (2004). Chelonia mydas. The IUCN

Red List of Threatened Species 2004

Serafy, J.E., Lutz, S.J., Capo, T.R., Ortner, P.B., and Lutz, P.L. (1995). Anchor tags affect

swimming performance and growth of juvenile red drum (Sciaenops ocellatus). Mar.

Freshwater Behav. Physiol., 27, 29–35.

Shaughnessy, P.D. (1994). Tag-shedding from South African fur seals (Arctocephalus pusillus

pusillus). S. Afr. J. Mar. Sci., 14, 89–94.

Siniff, D.B., and Ralls, K. (1991). Reproduction, survival and tag loss in california sea otters.

Mar. Mammal Sci., 7, 211–299.

20

Snape, R.T.E., Broderick, A.C., Çiçek, B.A., Fuller, W.J., Glen, F., Stokes, K., et al. (2016). Shelf

life: neritic habitat use of a turtle population highly threatened by fisheries. Diversity

Distrib.,

Solow, A.R., Bjorndal, K.A., and Bolten, A.B. (2002). Annual variation in nesting numbers of

marine turtles: the effect of sea surface temperature on re-migration intervals. Ecol.

Lett., 5, 742–746.

Stevick, P.T., Palsbøll, P.J., Smith, T.D., Bravington, M.V., and Hammond, P.S. (2001). Errors

in identification using natural markings: rates, sources, and effects on capture-

recapture estimates of abundance. Can. J. Fish. Aquat. Sci., 58, 1861–1870.

Stobo, W.T., and Horne, J.K. (1994). Tag loss in grey seals (Halichoerus grypus) and potential

effects on population estimates. Can. J. Zool., 72, 555–561.

Stokes, K.L., Fuller, W.J., Glen, F., Godley, B.J., Hodgson, D.J., Rhodes, K.A., et al. (2014).

Detecting green shoots of recovery: the importance of long-term individual-based

monitoring of marine turtles. Anim. Conserv., 17, 593–602.

Thompson, D., Lonergan, M., and Duck, C. (2005). Population dynamics of harbour seals

Phoca vitulina in England: monitoring growth and catastrophic declines. J. Appl.

Ecol., 42, 638–648.

Tucker, A.D. (2010). Nest site fidelity and clutch frequency of loggerhead turtles are better

elucidated by satellite telemetry than by nocturnal tagging efforts: Implications for

stock estimation. J. Exp. Mar. Biol. Ecol., 383, 48–55.

Wyneken, J., Epperly, S.P., Higgins, B., McMichael, E., Merigo, C., and Flanagan, J.P. (2010).

PIT tag migration in seaturtle flippers. Herpetol. Rev., 41, 448.

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Appendices Appendix 1: ethical approval

Appendix 2: risk assessment

DSE User Self-Assessment Form

Name of DSE User Kelle Holmes College / Service / Dept Date of Assessment 10/09/2015 CLES - Biosciences

DSE Component NO

YES Action Required /

Comments Desk

Is there enough space on your desk top for the flow of work?

1 Y

Have you got enough leg room? 2 Y Is the desk deep enough for you to have the monitor set between 450mm and 650mm from your eyes, when you are seated in the correct position?

2*

Y

Is there enough room for a space between your keyboard and you for your wrists to rest on the desk (4-6 inches / 10-14cm recommended) between typing

2*

Y

Is your desk surface free from reflection? 1 Y Chair

Is your chair at a height where the bottom of your elbows are at the same height as the keyboard when using the keyboard?

2 Y

Does the back rest support the small of your back in an upright posture?

1 Y

22

DSE Component NO

YES Action Required /

Comments Can you sit back into the chair seat fully without any pressure behind the knees?

2 Y

If fitted, are armrests set up correctly i.e not preventing adequate movement of the chair?

1 N/A

Can you get close to the desk to type with the elbows vertically under the shoulders?

2 Y

Is the chair comfortable? 1 Y Is the chair stable and all adjustment levers working? 2 With seat height adjusted correctly for the elbows, can you place your feet firmly on the floor without compressing the underside of your thighs?

2 Y

If a footrest is required, have you got access to one? 2 N/A Footrest not needed Monitor

Is the monitor / screen between 450mm-650mm away from your eyes (arms length)

2 Y

Is the monitor directly in front of you? 2 Y Are your eyes level with the top of the screen? 1 Y Is the screen free from glare / reflections? 2 Y Close curtains, alter angel

of lighting Is the information on the screen well defined and easy to read?

1 Y Use font size 11 or higher

The image is flicker free? 2 Y Do you clean the screen regularly? 1 Y Is the monitor tilted between 5 and 15% off the vertical? 1 Y Can you adjust the brightness and contrast easily? 1 Y

Keyboard Is the keyboard at the correct angle to prevent any up or down bending of the wrist?

2 Y

Is your keyboard far enough away from you to ensure your elbows are directly under your shoulders when typing?

2 Y

Do you always move your keyboard out of the way when you are using only the mouse?

1 Y

Is the keyboard clean? 1 Y Are the digits clear and not faded? 1 Y

Mouse Is the mouse close enough to avoid extending the arm at the elbow?

2 Y

If you have a roller ball mouse (laser mice do not need a mouse mat), do you have a mouse mat?

1 N/A Laser mouse being used

Does the mouse run freely on the mat and work accurately?

1 Y

Do you regularly clean your mouse and internal mouse ball?

1 Y

Do you reduce the time using your mouse to the lowest period possible by using keyboard short cuts?

2 Y

Document Holder Do you have a document holder (if required)? 1 N/A Not required Can you refer to documents and papers without having to move your head?

1 Y

23

DSE Component NO

YES Action Required /

Comments Other Equipment

Is all equipment and items around you necessary? (or can it be removed to give you more desk space?)

1 Y

Is all other equipment (phone etc) in a position to ensure that you can maintain your posture when using them?

1 Y

Space and environment Can you move in and out of your workstation easily? 2 Y Is there adequate space to manoeuvre your chair?

2* Y

Is the area free from trailing cables which pose a trip hazard?

2 Y

Is lighting adequate? 2 Y Do windows have blinds to prevent glare and reflection? 1 Y Do you find the work station quiet enough? 1 Y Is the temperature comfortable for most of the time? 1 Y

Are you free from any upper body pain/soreness or any soreness in your hands or wrists

2*

Y

About You Have you had an eye test in the last 2 years? Please follow this link to eye test information

2 Y Summer 2014

Do you organise your work to ensure you take a 5 minute break for every hour you are using the DSE?

2 Y Regular breaks away from DSE

Is your workstation set up to ensure that you have a flow of work (you don’t have to keep getting up or twisting for things)?

1

Y

Do you feel you understand and can effectively use all of the computer programmes you have to use as part of your job?

2 Y

Do you have an existing medical issue that you feel is being aggravated by your workstation?

N Y* score

2

None

Do you suffer from dry or sore eyes when using your DSE? N Y* score

2

None

Do you feel you require extra DSE information or training? N Y* score

2

none

Total Score 2

Action Plan

Actions Required Responsible Person

Date for Completion

Copy of the DSE assessment must be sent to Line Manager. Place in personal file.

DSE USER IMMEDIATE

Date set for next assessment (annual re-assessment required) N/A