(LISPIP) : Feb 2010 - Cornwall Seal Group

Transcription

(LISPIP) : Feb 2010 - Cornwall Seal Group
Identifying and monitoring Looe seals
Looe Island Seal Photo Identification Project 2008/9 (LISPIP) : Feb 2010
LISPIP is a collaborative project between the Looe VMCA Marine Volunteers, Cornwall Wildlife Trust and
Cornwall Seal Group, which aims to discover the following information:• The sites used by seals in the sea and on land
• The seasonality of any seal sites
• The number of seals visiting the sites
• Information about the seals’ ages, sex as well as information about their nutritional and health status
• Links to other seal sites in Cornwall made by individual seals, using photo identification techniques.
This information will provide a more informed basis upon which conservation decisions can be made.
February 2010 : Method
On 17th February 2009, 13 surveyors (Abby, Alan, Cheryl, Chris, Christine, Derek, Emma, Kate, Katie, Kym,
Matt, Nicola and Sue) were ferried over to St George’s Island on the CWT boat by Tim, leaving Looe
harbour around 9.30am and returning just before 5pm. The following activities were carried out:• A planning meeting to organise the day’s activities
• A walk around the island to:o Orientate surveyors
o To identify survey sites
o Familiarise new observers with the recording protocol (new surveyors paired with experienced ones)
o Carry out a bird count
• A 21/2 hour survey period from approximately 1 hour before low tide to 1 hour and 30 mins after low tide
• A data collection discussion and analysis
Seal survey sites
• Site 1 : Main Beach
• Site 2 : Jetty Beach
• Site 3 : Little Island East*
• Site 4 : Inner Ranneys Bay
• Site 5 : Outer Ranneys
• Site 6 : Lower Bench
• Site 7 : White Rock
*(Only accessible outside the bird breeding season)
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As a result of the pilot survey and our first familiarisation walk around the island, the following decisions
were made about the LISPIP Survey Protocol:• To conduct monthly seal surveys during 2009, weather and sea conditions permitting
• Surveys to be undertaken within a window of 2 hours either side of low tide
• Surveyors to work in paired teams or trios (mixing new and experienced observers where appropriate)
• One surveyor to remain at sites 3, 4 and 5 to take digiscoped images of seals present, to maximise
photo ID potential
• Survey teams to rotate clockwise around the survey sites
• Survey teams to begin walking to the next site at agreed half hour intervals
• During each survey period, the following data to be recorded:o The maximum number of seals to be counted in and out of the water
o Seals to be classified as adult male, adult female, juvenile male or female (up to 4 years old),
weaner (under 1 year old), white coat pup (under 3 weeks) or unknown
o Seal behaviour using a detailed ethogram
o Evidence of net entanglement, marine debris and disturbance
o Environment conditions
• Human/seal interaction is noted, including feeding, marine litter, net entanglement & disturbance
• Disturbance to be minimised by:o Land based surveyors remaining quiet and still when being looked at by seals and keeping below
the horizon if close to seals on land.
o A quiet & slow boat approach. At the first signs of disturbance, a still silence to be maintained by
surveyors and the boat to back away if signs of seal stress continue.
• Side view photos of the seals necks/bodies to be taken using digital cameras with optical zoom lenses
with optical image stabilisers or by digiscoping. CSG has loaned the Looe VMCA volunteers a digital
camera to take shots of seals seen between surveys.
• Contemporaneous collation of sightings data in a time/location chart and discussion of likely overlap in
sightings using mapped location, sex/age and behaviour data.
• Anecdontal seal sightings outside of seal survey to be recorded, as appropriate.
• Seal sightings by Wardens Claire and Jon to be recorded between surveys using separate form.
• A count of the birds present will be recorded during a single, complete circumnavigation of the island.
February 2010 : Results
7 seal sites were surveyed from 5 different locations by survey teams of 2 or 3 people, whilst Sue remained
at site 5 to take digital digiscoped images of the seals on the Ranneys. At sites 3, 4 & 5, where possible,
the survey team separated, with one person surveying nearer to Little Island, survey site 3 & the other
person standing on cliffs west of Little Island.
Initial survey teams for each site were:• Site 1 : Main Beach : Katie, Matt & Nicola
• Site 2 : Jetty Beach : Christine & Derek
• Site 3 : Little Island East : Kate, Kym & Sue
• Site 4 : Inner Ranneys Bay : Kate, Kym & Sue
• Site 5 : Outer Ranneys : Kate, Kym & Sue
• Site 6 : Lower Bench : Alan & Chris
• Site 7 : White Rock : Abby, Cheryl & Emma
Date
17/02/10
Survey start
12.30pm
Survey end
15.00pm
Time of low water
13.30
Wind direction
S
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Number of seals observed and environmental conditions (*Thought to be the same seal moving between sites)
Site
12.00 to 12.30
12.30 to 13.00
13.00 to 13.30
13.30 to 14.00
Site Max
Behaviours
1
0
0
0
0
0
2
0
0
0
0
0
Wind force
Weather
Debris
ST
BR/W
1
Plastic cups
Red cloth
Net
Rubber disk
2
Plastic containers
Cans
3
0
0
0
0
0
4
0
0
0
0
0
5
2
1
1
1
1
6
0
0
0
0
0
7
0
0
0
0
0
W
BR
0
2
Green trawl net
and fishing floats
Total
2
1
1
1
1
WB, WDR, WDR, WDR,
WDR, WDR
W/BR/W
Overcast, sunny spells / Drizzle / Rain
1
Wood
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Two seals were seen during the first recording session by observers at sites 3, 4 and 5 and from site 6.
Both these seals were in the sea at site 5. One seal remained in the same location for the whole survey.
Behaviour recordings : (Please see the end of this section for behaviour code descriptions.)
WT
WD
WP
WF
WS
WE
WDA
WDR
WB
WL
WIB
HA
HR
HM
HTr
HTh
HF
WH
HW
0
0
0
0
0
0
0
5
1
0
0
0
0
0
0
0
0
0
0
The seals displayed 2 different behaviours during the seal survey. The most observed seal behaviour was
Water diving rest. This behaviour was displayed repeatedly by LF1 Snowdrop in the small bay on the NW
side of the Outer Ranneys.
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February 2010 : Discussion
Seals were only observed at one of the sites during the survey period – site 5, the outer Ranneys. Here
there were 2 adult seals in the sea – an adult female – LF1 Snowdrop and a seal of unknown age/sex.
Seal identification
One of the seals at site 5 was identified in the field using the new photo ID cards. The female’s pattern was
clearly identified from both sides as being LF1 Snowdrop, who has now been identified 6 times.
On the 15th February, Claire took photos of another adult female seal at site 4, who was identified from both
sides before the survey as LF3 Duchess, who has been identified a total of 5 times. Excellent photos of an
unknown adult male were taken by Claire on 06/02/10, which could have been Barry, but the identification
cannot be confirmed.
LF1 Snowdrop
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LF3 Duchess
15/02/10 : Site 4
15/02/10 : Site 4
ID file photo
ID file photo
15/02/10 : Site 4
ID file photo
Unknown male photographed by Claire on 06/02/10
LM 4 Barry : ID shot
Unidentified adult male
Possibly Barry?
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Identification summary:LF1 is LF2
LF3
LM4
LMF6
LF8
LM9
LMF10
LM11
LF12
LMF13
LF15
LM16
L17
Snowdrop
Duchess
Barry
Paw print
Lucille
Sunrise
Wotsit
Gus
Lightning
Nemo
Dame Etna
Arrow
Juvie
30/05/08
15/03/09
29/08/08
26/05/09
26/05/09
21/08/09
21/08/09
21/08/09
21/08/09
21/08/09
07/09/09
07/09/09
07/09/09
14/02/09
26/05/09
10/06/09
24/08/09
24/08/09
26/05/09
24/08/09
14/06/09
07/09/09
26/07/09
01/10/09
26/07/09
08/10/09
21/08/09
15/02/10
24/08/09
17/02/10
07/09/09
12/10/09
Seal disturbance
Whilst up to 3 war ships could be seen on the horizon to the south of the Ranneys, no other boats were
observed and no seals were disturbed before, during or after the survey.
Age and sex of observed seals
The maximum number of seals observed at all the sites around the island during a single half hour survey
period at all sites was 2 (recorded during 1 out of the 5 survey periods) Of these 2 seals seen, 1 was an
adult female and the other was of unknown age/sex.
Interaction with boats and feeding of seals by humans: No boats were present.
Marine debris : Marine debris was recorded at sites 1, 2, 5 and 7 including net, a rubber disk 0.5m in
diameter, red cloth, plastic cups, cans, wood and a long line of green trawl netting. A large pile of marine
debris has already been cleared up by Claire and Jon and awaits collection on the ramp at site 1.
Net entanglement :No net entangled seals were observed.
Seasonal distribution of seals observed : The maximum number of seals observed during this survey
appears to have stabilised at a lower level for the winter. This is only the second repeat survey month –
both December and February demonstrating a degree of inter annual variation, particularly in February, as
6 seals were seen at this time last year.
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Warden’s sightings : The seasonal wardens have recently returned to St George’s Island and begun their
seal recordings for 2010, of which a total of 11 records exist.
Most seals observed by Claire were seen at site 5, the Outer Ranneys, although seals were additionally
seen at sites 2 and 4 (the most noteable of which was LF3 Duchess!)
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The most frequently observed number of seals seen by Claire was 1.
Many thanks to everyone who took part in this seal survey. Surveyors volunteer their time and paid a £5
contribution each to the cost of the boat crossing with the remaining cost being met by Cornwall Wildlife
Trust. Thanks too to Claire, whose records taken between LISPIP surveys greatly adds to our
understanding of seal activity at this location. Thanks to Abby Crosby for organising this seal survey. In
future, it was agreed that Katie, Matt and Nicola will organise the surveys in collaboration with Claire.
Sue Sayer
Cornwall Seal Group
sue@cornwallsealgroup.co.uk : www.cornwallsealgroup.co.uk
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