Time Lapse Video Monitoringof
Manta Ray Bay
Great Barrier Reef Marine ParkAustralia
Thorne Abbott
CoastalZone.com
Concerns & Conflicts
• Concerns over coral damage from– anchors
– diver fins
– contact by snorkelers
• Fish feeding• Trash & refuse• Water quality
• Number of Moorings– Commercial: more
– Residents: less
• Boat tethering• Dinghy access to beach• Overcrowding during
water activities
Challenge . . .
Design a self-contained monitoring system that could be used at remote locations
in the Great Barrier Reef Marine Park
to enhance sustainable use decision-making
Objectives
Determine appropriate sampling strategies for video
monitoring
Analyze the resolution or clarity of the imagery produced
Calibrate the validity of the data generated
Determine if the results obtained can enhance decision
making
Monitor Equipment
• Camera• wide angle lens
• polarizer
• zoom facility
• Processor• Battery Re-charger• Solar Panel• Battery's
• Monitor Housing• prospecs lens
• telescoping stand
• tripod head
• camera housing
• padlocks, security
• Laptop Computer• Software
• Battery
Monitoring Performance0
1020
30
Nu
mb
er o
f D
ays
To
tal
Da
ys
Mo
nit
ore
d
Fa
ile
d
Op
era
tio
na
l
Gro
un
d-
tru
the
d
• The monitor worked 43% of the time
• 83% of the video samples were ground-truthed by physical observation
• When operational, activity was observed 41% of the time
Video Footage
Vessels172 samples 20 seconds each
Visitors52 samples originally 20 seconds each
Master Tape High Resolution S-VHS Format
12 Data TapesHigh Resolution Hi - 8 Format
Video Camera Monitoring
Results of Sampling StrategyTable 1 : Vessel Excursion Information
RecordingTime
Numberof
Vessels
Number ofExcursions
Numberof
Samples
SamplingPeriod
Commercial Vessels 20:55 6 15 34 %Private Vessels 10:40 18 12 17 %Dinghy’s 6 6Vessel Activity 25:40* 24 33 120 41 %*Visitor Activity 52Total Activity 25:40* 172 41%*No Activity 59%NB .: *Some samples included multiple vessel types at the same time.
Vessel Samples
Number of Visitors"expected"
Size Time
Type Day
Mooring Date
Vessels172 samples 20 seconds each
Vessel Sizes at Moorings
187710N =
Ve s se l S ize s a t M oo rings
all Vessels
MOORING
QueuingNot MooredCBA
SIZ
E in
met
ers
1614121086420
Vessel Patterns Vessels ranged from 3 m to 15 m long
Moored vessels averaged 10 m long
Most private vessels exceeded 10 m
Private vessels visit the bay as often as commercial vessels
Commercial vessels use the bay for twice as long Dinghy’s were often used in the bay
Mooring Times
187710N =
M oo ring Ince ptio n T im e o f D a y
all Vessels
6 = 6:00 AM18 = 6:00 PM
MOORING
QueuingNot MooredCBA
TIM
E o
f Day
18
12
6
.
Length of Stay
576114N =
D ura tio n o f A nc ho rage
by Vessel type
Private YachtPriv. Motor Boat
DinghyDaily Tour Oper.
Comm. Charter
DU
RA
TIO
N in
min
utes
300
200
100
0 .
Mooring Patterns Vessels moored between 10 AM and 4 PM Vessels arriving between 2 PM and 3 PM often
queued or did not use a mooring Average stay was two hours, three hours maximum* Two vessels moored overnight* Vessels that moored, did so within 20 minutes Mooring “C” was used last, least, and for less than
one hour
SCUBA DivingNum be r o f S c uba D ive rs
by Time of Day
TIME
5:003:30
3:002:45
1:551:45
1:201:00
12:4012:20
12:0011:40
11:0510:40
10:20
Num
ber o
f Dive
rs
8
6
4
2
0
Snorkeling
by Time of Day
TIME of Day
5:003:30
3:203:00
2:301:55
1:401:00
12:4012:20
11:4011:05
10:20
Num
ber o
f SNO
RKEL
LER'
s
16
14
12
10
8
6
4
2
0
N u m b e r o f S n o r k e l l e r s
Visitor Patterns
Most activity takes place between 10 AM and 4 PM
Scuba divers visit morning to mid-daySnorkelers visit in the afternoonSubstantially more snorkelers than divers
Visitor Samples
Low Resolution VHS std FormatVisitor Counts by 3 Observers
High Resolution S-VHS FormatVisitor Counts by 4 Observers
19 @ 20 seconds19 @ 10 seconds19 @ 5 seconds19 @ 1 second
19 original samples4 sub-samples per original
14 @ 20 seconds14 @ 10 seconds14 @ 5 seconds14 @ 1 second
30 original samples1, 2, or 3 sub-samples per original
Randomness
Visitors52 samples originally 20 seconds each
Effect of Resolution& Sample Length
P e r c e n t a g e O b s e r v e d t o E x p e c te d
L e n g t h o f S a m p le ( T IM E )
2 0 se conds1 0 se conds5 se conds1 se cond
Pe
rce
nta
ge
Ob
se
rve
d
T a p e F o rm a t
V HS std.
S -V HS
1.0.9.8.7.6.5.4.3.2.1.
Comparison o f Visitor Counts
VHS std. to S-VHS Tape Formats
Accuracy of Observers Estimatesof Visitor Activity
0
20
40
60
80
100
1 5 10 20Length of Recorded Sample
(seconds)
Per
cen
tag
e A
ccu
racy
VHS standard resolution S-VHS high resolution
Methodology
The Method of Monitoring can be» consistent (Chi^2 : p>.05)» accurate (>70%)» using HIGH resolution tape format» and samples 10 seconds or longer
Recommendations• Install a shared commercial mooring
• Update signage in the bay
• Pre-program the micro-processor for sampling
• Upgrade to a 12 volt auto battery power source
• Sampling strategy:
– 15 minute intervals
– from 9 AM to 5 PM
– recordings 10 to 15 seconds in length
Recent Applications
• Time-lapse video monitoring of boat traffic in Missionary Bay and Hinchinbrook Channel, World Heritage Area
• Establish Dugong movement patterns and their interactions with boat traffic.
• 2500 samples collected to date
Opportunities Underway• Web-based remotely controlled panoramic views of
coral reefs and fish for educational purposes
• Monitoring of diseases in coral assemblages
• Monitoring changes in size, volume, and coverage over time at specific sampling locations
• Coral coverage based on video transects
• Measuring the effect of fragmentation on meta population sustainability
• Assessing reef health and viability at various scales
Conclusion
Time lapse video monitoring
provides valuable data
on visitor and vessel patterns of use
assisting managers in designing
sustainable management options
Acknowledgements Great Barrier Reef Marine Park
Authority
Ray Berkelmans
Graeme Inglis
The Coastal Society
CRC Reef Research Centre
Queensland Dept. of Environment & Heritage
James Cook University Dept. of Tropical Environmental Studies & Geography
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