Manta Project Fiji Impact Report 2023

the Yasawa
islands
The Manta
Channel
Key Partner
Barefoot Manta
Island Resort
Barefoot Manta Island Resort has been an integral
partner of Manta Project Fiji since 2012. As our
initial partner in country Barefoot Manta Island
Resort has contributed significantly to the research
efforts within the Yasawa Islands, leading the way
towards sustainable manta ray encounters at the
Manta Channel.
The main reef manta aggregation site is just off the
island, where strong currents funnel zooplankton
into the shallow channel between Drawaqa and
the largest island in the Yasawas, Naviti. Barefoot
Manta staff and MPF researchers collect daily data
on the manta rays sighted, building an invaluable
data set which will allow effective management
strategies to be developed.
Project Overview
The Yasawa Islands are made up of 11 main volcanic islands running 90 km
to the North-East of Fiji’s main island, Viti Levu. These islands are one of Fiji’s
busiest tourist destinations and attract almost 90,000 visitors every year. The
Manta Channel is located towards the southern end of the island chain between
Drawaqa Island and the largest island in the chain, Naviti Island. This small
channel is approximately 250m long, 300m wide and 7m deep at high tide in the
deepest section. The channel is dominated by hard coral and is subject to high
currents during the daily tidal fluctuations.
During the cooler drier months from April through to October reef manta rays
(Mobula alfredi) aggregate at the Manta Channel to forage on dense zooplankton.
Since 2012 we have collected photo identification data on the manta population
along with environmental and anthropogenic data. This data allows us
to monitor the population dynamics and demographics over time as well as allowing
us to gain an insight into population 2022-2023
connectivity and movement ecology.
Environmental and anthropogenic data allows us to monitor the environmental
conditions that create favourable foraging conditions and importantly allow us
to monitor the interactions between the tourism industry and manta ray
sightings.
No. of
Days
200
150
141
100
50
0
Annual Survey
Days
205
162 170 153
215 224 230 201 190
2013 2014 2015 2016 2018 2019 2020 2021 2022 2023
Percentage
100
90
80
70
60
50
40
30
20
10
0
79% 82% 68%
Reef Manta Ray
(Mobula alfredi)
78%
54%
58% 63% 60%
Percentage of Survey
Days Manta Rays
Sighted
70%
Average Number of Snorkelers
58%
2013 2014 2015 2016 2018 2019 2020 2021 2022 2023
As the busiest tourist destination for manta ray watching in Fiji, the Manta Channel is subject to
heavy anthropogenic pressures, such as snorkelling and boat traffic. A correlation does not
necessarily indicate causation however there is a clear negative correlation between the average
number of snorkelers visting the site per day vs the number of manta rays sighted. During 2023
we recorded 213 manta ray sightings of 27 different manta rays, with an average of 41 snorkelers
in the Manta Channel.
55
2013
2014
2015
2016
2018
2019
2020
2021
48
2022
2023 43
41
COrrelation = causation?
Numbers display average
number of snorkelers with
manta rays
36 36
Average number of snorkelers
VS
45
42
Annual Manta Ray Sightings
0
0 Number of Manta Ray Sightings
600
2023 in review
Surveys were conducted on 190 days between April - October
Manta rays were sighted on 58% of survey days
199 drone flights were conducted
2013 - 2019 and 2023
display much higher
average numbers of
snorkelers with a much lower
number of manta ray
sightings
We recorded 213 manta ray sightings. This is one of the lowest annual
sighting totals on record, a 64% reduction when compared to 2022.
27 different manta rays were recorded, a 50% reduction when
compared to 2022
The top five sighted manta rays made up 72% of all sightings in 2023
There were an average of 41 snorkelers in the water when manta rays
were present, one of the highest on record
169 (79%) sightings were of female manta rays and only 44 (21%) of
male manta rays
3
18
2020 - 2022 display much
lower numbers of
snorkelers with a much
higher number of manta ray
sightings
4