2012 Assessment Period - Manta alfredi
Species Information
1. TAXONOMY
Provide detail on the species' taxonomy, including whether or not it is conventionally accepted.
Kingdom: ANIMALIA
Phylum: CHORDATA
Class: CHONDRICHTHYES
Order: RAJIFORMES
Family: MOBULIDAE
Scientific Name:
Manta alfredi
Common Name/s: English – Reef Manta Ray, Coastal Manta Ray, Inshore Manta Ray, Prince
Alfred's Ray, Resident Manta Ray (Marshall et al. 2009).
Indigenous Name/s: No known Indigenous Names.
Manta alfredi has recently been described (Marshall et al 2009). Prior to this publication, the
genus Manta was considered to be monospecific, with M. birostris having a worldwide
distribution. This recent taxonomic revision recognised at least two distinct species, M. birostris
and M. alfredi, and a putative third species, M. cf. birostris (Marshall et al. 2009). M birostris is also
found in Australian waters (reported semi regularly in Western Australia), but in much lower
population numbers relative to M. alfredi (XXXX XXXX, unpubl. data; XXXX XXXX, unpubl. data).
2. DESCRIPTION
Describe the species, including size and/or weight, social structure and dispersion (e.g. solitary/
clumped/ flocks), and give a brief description of its ecological role (e.g. is it a ‘keystone’ or
‘foundation’ species, or does it play a role in ecological processes such as seed dispersal or
pollination).
Species Description:
M. alfredi is a large filter-feeding elasmobranch reaching up to 5000mm disc width (DW) and is
circumglobally distributed in tropical and subtropical waters (Figure 1) (Couturier et al., 2012). DW
at maturity for the species is estimated to be 2700 – 3000mm for males and 3700-3900mm for
females (Clark, 2010; Deakos, 2010; Marshall & Bennett, 2010). Manta rays have two cephalic
lobes on the front of their heads that are used to help the water flow into their mouth. Their broad
mouth is located at the distal end of the head with a single band of minute teeth within the upper
jaw. Their eyes and spiracle valves are located on the side of their heads. They have a single small
dorsal fin near the tail, and are lacking a stinging spine. They have five gill openings ventrally
located. Their gills are modified into complex sieving plates through which they extract oxygen but
also filter their planktonic food from the water. Manta alfredi is an ectothermic species, however,
studies have shown that Manta species have a counter current – heat exchanger system, allowing
regulation of their internal brain temperature (Alexander 1996).
Social Structure and Dispersion:
M. alfredi predictably aggregates at particular locations. These aggregations are associated with
seasonal availability of food, the circulation patterns of currents, sea water temperatures, mating
behaviour and cleaning station visitation. Reef mantas are regularly present at cleaning stations in
shallow reefs and costal feeding grounds during daylight hours and move to deeper, offshore
waters during the night (Anderson et al., 2011; Clark, 2010b; Couturier et al., 2011; ). Maximum
movement recorded for Manta alfredi individuals is currently slightly over 500 km (Couturier et al.,
2011) .
Ecological role:
M. alfredi is a planktivorous species, feeding low down on the food chain (Couturier et al 2012,
Jaine et al 2012). Manta rays are an important indicator species in regards to impacts caused by
loss of climatic habitat caused by anthropogenic emissions of greenhouse gases, as their planktonic
food source is highly sensitive to environmental changes. Climate change influences the
abundance, distribution and phylogeny of the plankton (Hays et al. 2005; Richardson, 2008), which
most likely directly impact manta ray distribution and behaviour.
M. alfredi provide important mid water habitat for many species of fish, including several
commercially important species of trevally, black king fish, plus remoras and pilot fish (XXXX XXXX,
unpubl. data). Finally they provide a food source for a large range of species – from the cleaner
wrasse, moon wrasse and butterfly fish that consume parasites and dead flesh removed from
individual manta rays, through to medium to large sharks and orcas which have been observed
consuming large bites of flesh through to consuming the entire animal (Fertl et al., 1996; Homma
et al., 1999; Ebert, 2003; Visser and Bonoccorso, 2003; Marshall and Bennett 2010; Deakos et al.,
2011, Couturier et al., 2012)
3. BIOLOGY
Provide information on the species' biology, including its life cycle, generation length, reproductive
and feeding characteristics and behaviours.
The information available on the biology of M. alfredi is currently limited. Here we present all
known and recorded biological data. Detailed information can be found in Couturier et al. 2012.
Life Cycle:
M. alfredi has longevity greater than 31 years (Clark, 2010). The species is aplacental viviparous,
with embryos developing within the uterus. Embryos initially feed on yolk and are later nourished
by uterine milk (Wourms, 1977). The gestation period is between 12 and 13 months, with an
occasional resting period of two of more years between pregnancies (Marshall and Bennett
2010a). Males reach sexual maturity between the ages of three to six years (Clark 2010). Female
sexual maturity ages are unknown. Females usually give birth to only a single pup, though cases
where two pups have been birthed have been infrequently recorded (Clark, 2010; Marshall &
Bennett, 2010). Limited data is available regarding generation lengths but is suspected as being 25
years (Marshall et al. 2011a).
Natural Mortality:
Natural predation rate on adult M. alfredi is believed to be low. Sharks are suspected as the most
common predators, though many attacks are non-fatal (Marshall and Bennett, 2010b; Deakos et
al. 2011).
Reproduction:
Critical knowledge gaps still exist for M. alfredi reproduction. Manta rays employ internal
fertilization to reproduce (Wourms, 1977) and the mating process consists of a complex ritualised
sequence that involves chasing, biting, copulating, post-copulation holding and separation;
requiring many kilometres of space to perform these behaviours (Marshall and Bennett 2010a).
Feeding:
Manta rays are planktivorous and their modified gills are used to sieve plankton out of the water
(Bigalow and Schroeder, 1953; Cortes et al., 2008). The species feed by swimming with an open
mouth allowing a water flow through a gill-raker apparatus; a behaviour called ram filter feeding
(Sanderson and Wassersug, 1990; 1993, Cortes et al., 2008). Other observed behaviours include
chain feeding, where aggregates of individuals follow each other in a circular movement creating
cyclonic motions (Law, 2010).
Diet:
Based on one stomach content analysis, M. alfredi was confirmed to feed on zooplankton (Whitley,
1936). Seasonal aggregations of other mobulid rays have been recorded as coinciding with the
peak abundance of animal prey species ( Whitley 1936; Notarbartolo di Sciara, 1988). 'Loss of
climatic habitat caused by anthropogenic emissions of greenhouse gases' is a listed key
threatening process that could impact their seasonal diet (Couturier et al 2012). As oceanic
temperatures are expected to warm by 2–3 °C by 2070 (IPCC, 2007), the zooplankton community is
likely to respond in terms of changes in abundance, timing and productivity both globally and
locally (Edwards & Richardson, 2004; Richardson & Schoeman, 2004). As such, both the feeding
grounds and diet of M. alfredi are likely to be affected by loss of climatic habitat caused by
anthropogenic emissions of greenhouse gases.
Movement:
Although the knowledge on the movement patterns of M. alfredi is still in its infancy, the species is
known to migrate relatively long distances, moving between productive areas and aggregating at
specific sites (Couturier et al., 2011). Individuals can travel up to 70km in a single day (van
Duinkerken, 2010). Photographic Identification studies have shown that seasonal migrations of at
least 500km occur between known aggregation sites (Couturier et al., 2011).
4. HABITAT
Describe the species’ habitats and what role they play in the species' life cycle. Include whether or
not the species is associated with, or if it relies on, a listed threatened ecological community or
listed threatened species?
M. alfredi is commonly sighted inshore, around coral reefs and rocky reefs in coastal areas. Longterm sighting records suggest that this species is mostly resident to tropical and subtropical waters
(Marshall et al 2009; Marshall et al., 2011a). The species has been recorded as being sympatric in
some locations and allopatric, with the Giant Manta Ray M. birostris, in others (Kashiwagi et al.,
2011).
M. alfredi predictably aggregates to particular locations such as Lady Elliot Island, North
Stradbroke Island and Byron Bay in eastern Australia, for which they display a high degree of site
fidelity (i.e. visit the same site over time) and residency (Couturier et al. 2011; XXXX XXXX, unpubl
data)). Species residency is also recorded along the Western Australian coast line, with populations
recorded in Ningaloo Marine Park (Figure 4) (XXXX XXXX, unpubl. data,). Aggregation sites for M.
alfredi in Australia have been identified as feeding areas, cleaning stations, reproductive sites and
potential migratory landmarks (Couturier et al. 2011). As such, aggregation sites are strongly
believed to represent critical habitats for this species.
Long term site fidelity has been recorded for M. alfredi in other parts of the world, such as
Indonesia (Dewar et al. 2008), Mozambique (Marshall 2009), the Maldives (Kitchen-Wheeler 2012),
Hawaii (Deakos et al. 2011) and eastern Australia (XXXX XXXX, unpubl. data).
The migratory nature of M. alfredi is thought to be influenced by local oceanographic conditions
(e.g. current dynamics) and related to seasonal productivity (Anderson et al., 2011; Couturier et
al., 2011, XXXX XXXX unpubl. data).
Population Size
5.
a.
b.
NUMBERS
What is the total number of mature individuals? How was this figure derived?
Identify important populations necessary for the species’ long-term survival and recovery.
a. Estimates of total population size for M. alfredi are very difficult to assess due to the
migratory nature and global distribution of the species (Couturier et al., 2012). Regional
population size estimates using sight-resight data in Mozambique and Hawaii showed that
regional populations are small (less than 900 individuals) (Deakos et al., 2011; Marshall et
al. 2011b). In contrast, population estimates of M. alfredi at key aggregation sites in the
Maldives archipelagos ranges between 181 and 562 individuals, while the population for
the entire Maldives, where several protection and conservation acts were enacted to
protect the species, was estimated between 9,677 individuals (Kitchen-Wheeler et al. 2011)
and 5000 (XXXX XXXX, unpubl data). Minimum numbers of M. alfredi individuals identified
are provided in Kashiwagi et al. (2011) for other locations. Apart for the Maldivian
population (n=1835; Kitchen-Wheeler et al. 2011), all minimum numbers of individuals are
less than 700 individuals per location. To date, no interaction between regional populations
has been found and dispersion of individuals is likely to be restricted by bathymetric
features and/or regional ocean circulation patterns, isolating the different sub-populations
(e.g. Hawaii, Deakos et al 2011).
In eastern Australia, the minimum number of M. alfredi identified between Osprey Reef
and South Solitary Island is 620 (XXXX XXXX, unplubl. Data, data collected between 20082012).
In Western Australia the metapopulation of M. alfredi is thought to be between 1200 –
1500 individuals, with 560 individuals identified within Ningaloo Marine Park (XXXX XXXX
unpubl. data).
b. As the Australian populations are currently unaffected by directed fisheries, we argue that
their protection contributes significantly to maintaining the global population. Experts
consulted on this application agree that the Australian population, based on current
evidence, is currently one of the world’s healthiest and concur that the conservation of this
population is not only important for Australia, but globally. However, the authors of this
application acknowledge that this is currently speculation, as proper population size
estimates over several years are required to support this statement. Important populations
that contribute to the species’ long-term survival and recovery include the Queensland (e.g.
Lady Elliot reef, Musgrave Reef, North Stradbroke Island, Osprey Reef), Western Australia
(Ningaloo Reef, Coral Bay) and New South Wales (Solitary Islands, Byron Bay) populations.
6.
POPULATION TREND
a.
What is the population trend (PAST to CURRENT) for the entire species? Is the population
trended increasing or decreasing, or is the population static? Provide relevant data sources.
b.
Is this trend likely to continue, or are there any data which indicate FUTURE changes in
population size? Provide relevant data sources.
c.
Does the species undergo extreme fluctuations in the number of mature individuals?
a) Manta rays are targeted by fisheries in some parts of the world. A such, population reduction
appears to be very high in several regions; up to as much as 80% over the last three generations
(approximately 75 years), and globally the species is believed to have declined by >30%. In some
region, manta ray populations have collapsed due to directed fisheries (e.g. Anon 1997; Alava et al.
2002). The population trend for M. alfredi is stated as ‘decreasing’ by the IUCN Red List. (Marshall
et al., 2011a).
b) Manta ray gill rakers are of high value on the international market. The rising demand by Asian
market in these manta ray products has led to a considerable rise in unregulated fisheries targeting
M. alfredi in several parts of the world (see Couturier et al. 2012). In some regions, over 1500
manta rays can be caught per year, a number that is considered unsustainable due to the
conservative life history of the species. Particularly threatening to M. alfredi is the fact that some
fisheries harvest individual manta rays in large numbers at critical habitats or aggregation sites
(Anon 1997; Marshall et al. 2011a; Couturier et al. 2012). The species is also caught in artisanal
fisheries for food, as by catch in large-scale fisheries, shark control programs and bather protection
nets (Marshall et al. 2011; Couturier et al. 2012).
c) This species is not recorded as undergoing natural extreme population fluctuations as it is a
long-lived, slow-growing, k-selected species (Marshall et al. 2011a).
7. PROBABILITY OF EXTINCTION IN THE WILD
Identify and explain any quantitative measures or models that address the probability of the
species’ extinction in the wild over a particular timeframe.
Sustained pressure from directed fishing and by-catch is likely to cause rapid decline in subpopulation abundances and due to the low fecundity and long life span of M. alfredi, subpopulations do not have the capacity to recover from a depleted state (Alava et al., 2002;
Mohanraj et al., 2009; Marshall et al. 2011a). The isolation, low immigration rates and
reproduction rates of manta rays impend on the population’s capacity to recover from the
depleted state imposed by these fisheries (Marshall et al. 2011a; Couturier et al., 2012) . Of
particular concern is the fact that fisheries harvest individual manta rays in large numbers at
critical habitats or aggregation sites (Anon 1997; Marshall et al. 2011a; Couturier et al. 2012).
Although global extension risk of the species cannot be assessed at this stage, M. alfredi is highly
vulnerable to regional extinction in areas where the species is fished. A study of an Indigenous
community in Indonesia showed numbers of animals caught went from up to 360 per annum,
down to zero; essentially a local extinction (Barnes, 2005).
Geographic Distribution
8. GLOBAL DISTRIBUTION
Describe the species' known or estimated current and past global distribution (include a map if
available). Does the species exist in an EPBC Act listed ecological community?
M. alfredi occurs along the coastal area of the following countries (Figure 2):
Australia (West Australian, Northern Territory, New South Wales and Queensland coastal zones);
British Indian Ocean Territory (Chagos Archipelago); Cape Verde; Christmas Island; Cocos (Keeling)
Islands; Cook Islands (Cook Is.); Djibouti; Egypt (Egypt (African part), Sinai); Fiji; French Polynesia
(Society Is., Tuamotu); Guam; India (Andaman Is.); Indonesia (Bali, Irian Jaya, Jawa, Sulawesi);
Japan (Nansei-shoto); Madagascar; Malaysia; Maldives; Marshall Islands; Micronesia, Federated
States of; Mozambique; New Caledonia; Northern Mariana Islands; Oman; Palau; Papua New
Guinea (Bismarck Archipelago, North Solomons, Papua New Guinea (main island group);
Philippines; Saudi Arabia; Senegal; Seychelles (Seychelles (main island group); South Africa
(KwaZulu-Natal); Spain (Canary Is.); Sudan; Thailand; United States (Hawaiian Is.) and Yemen
(Kashiwagi et al. 2011; Marshall et al. 2011a; Couturier et al., 2012).
9. EXTENT OF OCCURRENCE within Australia
NOTE: The distribution of the species within Australia is assessed in two ways, the EXTENT OF
OCCURRENCE and the AREA OF OCCUPANCY. The two concepts are closely related, and often
confused. Therefore, before you answer this question, please see the definitions and explanatory
material in Attachment A.
a.
What is the CURRENT extent of occurrence (in km2)? Explain how it was calculated and
provide relevant data sources.
b.
Has the extent of occurrence changed over time (PAST to CURRENT)? If so, provide evidence.
c.
Is the extent of occurrence expected to decline in FUTURE? If so, provide evidence.
d.
Does the species undergo extreme fluctuations in the extent of occurrence? If so, provide
evidence.
a. The current extent of occurrence in Australia is calculated as 6,780,364 km2 (Figure 3). They can
be found as far south as Albany in Western Australia up and around to Sydney Harbour in New
South Wales, from coastal zones stretching through to the continental shelf.
This was calculated by using the CSIRO software “image J”, in which the scaled Google Earth image
was defined as the “area contained within the shortest continuous imaginary boundary which can
be drawn to encompass all the known, inferred or projected sites of present occurrence of a
species, excluding cases of vagrancy used as a guide to estimate the area in which the manta rays
inhabit”. The known locations were connected in a dot to dot fashion with the outer edge being
defined as the shelf edge (the 200m depth bar).
b. There is currently no evidence for change within Australian waters as population numbers are
only just being calculated. Without this baseline data, there is no ability to detect changes in
extent of occupancy. However, there is genuine concern in Western Australia, as many of the
individuals there appear to migrate across international boundaries and into targeted fishing
grounds to the north (XXXX XXXX unpubl. data).
c. In the case where the manta rays are protected from commercial fisheries and other human
impacts then it is predicted to remain stable. However, the current extent of occurrence in eastern
Australia is suggested to be linked with the circulation pattern of the East Australian Current. With
climate change predicted to impact on the ocean circulation, the future extent of occurrence of
manta rays is likely to be impacted and changed, however, it is not possible to determine to what
end.
d. In eastern Australia, M. alfredi mostly occurs within southern aggregation sites (i.e. south of
Lady Elliot Island) from spring to early autumn, while the species is seen in high numbers at Lady
Elliot Island during late autumn-winter months (Couturier et al. 2011). The seasonal fluctuations in
the extent of occurrence is part of the seasonal migration of the species that is likely to be
influenced by the East Australian Current circulation patterns (Couturier et al. 2011).
10. AREA OF OCCUPANCY
NOTE: The distribution of the species within Australia is assessed in two ways, the EXTENT OF
OCCURRENCE and the AREA OF OCCUPANCY. The two concepts are closely related, and often
confused. Therefore, before you answer this question, please see the definitions and explanatory
material in Attachment A.
a.
What is the CURRENT area of occupancy (in km2)? Explain how it was calculated and provide
relevant data sources.
b.
Has the area of occupancy changed over time (PAST to CURRENT)? If so, provide evidence.
c.
Is the area of occupancy expected to decline in FUTURE? If so, provide evidence.
d.
Does the species undergo extreme fluctuations in its area of occupancy? If so, provide
evidence.
a. The current area of occupancy is calculated at approx 29,458 km2 in eastern Australia
(Figure 4) and 76,012 km2 in Western Australia (Figure 5). These figures were calculated
using techniques described above using Image J – however this time drawing an elliptical
area around known manta aggregation spots including - Torres Strait Is, Osprey Reef,
Capricorn Bunker group (with Heron Is at the centre), Lady Elliot Reef, Wolf Rock, North
Stradbroke Island, Byron Bay (around Julian rock), Solitary Islands Marine Park and Sydney
Harbour in eastern Australia (Figure 4) plus an additional 16 identified locations in Western
Australia (Scott reef, Rowley shoals, Port Headland, Pt Sampson, Dampier Archipelago,
Montebellos, Exmouth Gulf, Ningaloo, Monkey Mia, Dirk Hartog, Geraldton, Abrolhous,
Cervantes, Jurien Bay, Perth and Albany) (Figure 5). This is based on both publications and
unpublished data from acknowledged experts in the field (Couturier et al 2011, XXXX XXXX
unpub data, XXXX XXXX unpub data).
b. As mentioned in section 22, baseline surveys have only recently begun for this species, so it
is not possible at this stage to provide evidence for change in population over historical
time.
c. While several of the recognised manta ray aggregation sites are currently protected within
marine park areas, a large portion are not, or are zoned in such a way that little to no
protection is credited to the species. Examples of this include Torres Strait Island, North
Stradbroke Island and Solitary Islands (in NSW).
d. Yes, the numbers of species fluctuate widely depending on season. For example, very few,
to no manta rays are found south of the Capricorn Bunker Group of the GBR during the
Australian late-autumn and winter (May to mid Oct). Conversely, numbers of manta rays
sighted at Lady Elliot Reef during that same time considerably increases (Couturier et al
2011, Jaine et al in press).
11. PRECARIOUSNESS
a.
Is the species' geographic distribution severely fragmented, or known to exist at a limited
number of locations?
b.
Is the area, extent and/or quality of the species' habitat in continuing decline (observed /
inferred / projected)?
c.
Is the number of locations or subpopulations in continuing decline (observed / inferred /
projected)?
d.
Are there extreme fluctuations in the number of locations or subpopulations of this species?
a. It has been identified that regional populations of manta rays are likely to be isolated from each
other due to bathymetric features and oceanic circulation patterns. It is probable that the manta
population from east Australia and west Australia are distinct from each other with little
connectivity. While oceanic species such as M. alfredi are not subject to the same degree of
fragmentation as terrestrial species, the species has site preferences where they can aggregate in
numbers (Couturier et al, 2011).
b. Manta ray habitats are in a continuing state of degradation. Coral reefs are well documented as
being impacted by loss of climatic habitat caused by anthropogenic emissions of greenhouse gases,
bleaching, crown of thorn outbreaks, fresh water run off carrying pollutants, anchor damage from
boating and ocean acidification (Hoegh-Guldberg, 1999; Hoegh-Guldberg et al., 2007; Hughes et
al., 2003; Selkoe et al., 2009). These issues effect not only corals, but also impact most trophic
webs, such as the planktonic food source of M. alfredi (Hays et al., 2005; Richardson & Schoeman,
2004).
Unmanaged tourism is also identified as a factor for manta ray habitats’ decline (e.g. Anderson et
al 2010). For example in the Maldives, a large number of tourists and boats are impacting critical
habitat of manta rays and can be the cause of high stress to the local population. As the diving
industry is flourishing, with more and more divers wishing to encounter this species (see Australia
Government 2008), aggregation sites and critical habitats of manta ray could quickly be impacted
by the influx of boats and divers to these locations if access to these sites is not regulated for
recreational activities.
c. The rate of population reduction appears to be high in several regions, up to as much as 80%
over the last three generations (approximately 75 years), and globally a decline of >30% is strongly
suspected (Marshall et al a). No information is currently available on the population trend of
manta rays in Australia.
The M. alfredi population in Australia is probably one of the healthiest worldwide as there are no
direct fishing pressures in this area (XXXX XXXX, pers. comm.). However, it is possible that part of
the Australian populations migrates to targeted fishing areas and thus be impacted by these
activities (XXXX XXXX, unpub. data).
d. Unless a directed-fishery for M. alfredi within Australian waters is created, the species is not
likely to undergo extreme population changes (Couturier et al., 2012).
12. PROTECTED AREAS
Is the species protected within the reserve system (e.g. national parks, Indigenous Protected Areas,
or other conservation estates, private land covenants, etc.)? If so, which populations? Which
reserves are actively managed for this species? Give details.
Western Australia: Only M. birostris is explicitly protected from any fishing and disturbance or
harassment and then, only within marine parks (The Government of Western Australia, 1994). As
the species classifications are out of date, the Fish Resources Management Act 1994 does not
recognise the two distinct manta ray species, as such M. alfredi is not protected (The Government
of Western Australia, 1995). Marine parks in WA cover only a small percentage (<10%) of total
known manta ray habitats.
Queensland: M. alfredi occurs with the Great Barrier Reef Marine Park and thus parts of its habitat
are covered under the GBR Marine Park Act and the EPBC section on World Heritage areas,
although there is no active management for the species.
Threats
13. KNOWN THREATS
Identify any KNOWN threats to the species, and state clearly whether these are past, current or
future threats.
If climate change is an important threat to the nominated species it is important that you provide
referenced information on exactly how climate change might significantly increase the nominated
species’ vulnerability to extinction. For guidance refer to the Guidelines for assessing climate
change as a threat to native species (Attachment B; Part B2).
Directed fishing
M. alfredi is targeted by fisheries around the world. The increase in demand for manta ray product
by the Asian Market (mostly for gill raker) has led to the creation of new and highly specialised
fisheries. Manta gill rakers are particularly sought for and valued; the trade for this manta product
has become more lucrative than the shark-fin trade (Heinrichs et al., 2011; Marshall et al. 2011;
Couturier et al. 2012). Individuals are captured and killed by various fishing methods, such as
harpooning, netting and trawling (Couturier et al., 2012). Some fisheries target manta rays at
aggregation sites using gillnets and can therefore harvest a large number of individuals with
relatively small effort (Anon 1997). In artisanal fisheries the species is captured using traditional
techniques such as harpoons, hand spears and hooks and lines (Alava et al., 2002).
Direct fisheries have significantly reduced the population abundance of several regions. In
Indonesia, over 1500 manta rays are captured each year (Dewar et al. 2002, White et al., 2006). In
several fished regions, manta ray populations have fully collapsed, demonstrated by dramatic
reductions in catch (Alava et al. 2002; Barnes 2005). In eastern Indonesia, the number of animals
caught by local indigenous villagers decreased significantly, dropping from up to 360 per annum,
down to zero (Barnes, 2005). The villagers reported that the dramatic decrease in manta catch was
due to the appearance of commercial fishing boats in the area (Barnes 2005). The fishing effort for
mobulid rays has increased internationally, but the annual landing in many areas is declining
(Dewar, 2002; Nair, 2003; White et al., 2006; Couturier et al., 2012). Major fisheries impacting the
species were also identified in Indian waters where over 70000 t of elasmobranchs are caught each
year (Banerjee et al., 2008). Mobulid rays can represent over 11% of the daily catch in some
regions (Zacharia & Kandan 2010). It is important to note that most manta ray fisheries around the
world remain unreported and illegal capture of these rays occurs even in protected areas.
It is highly probable that local and regional extinctions will occur in heavily fished areas.
Although no data is currently available, the manta population in WA is likely to swim across
international boundaries into the highly pressured Indonesian region and be exposed to local
directed fisheries. Figure 6 shows how known aggregation areas in WA and Indonesia are ~500Kms
apart. Given the ability of the species to migrate at least 500Kms it is likely that the Australian
populations migrate into Indonesian waters. The M. alfredi population in Australia is probably one
of the healthiest populations worldwide as there are no direct fishing pressures in this area.
However, it is possible that part of the Australian populations migrates to targeted fishing areas
and thus is impacted by these activities, as proposed by Couturier et al (2011).
Incidental capture as by-catch
Manta rays and other mobulids are regularly caught as by-catch in purse seine, trawl and net
fisheries throughout their distribution (Couturier et al., 2012). Tuna purse seine fisheries are a
major contributor to by-catch, with mobulid species caught in relatively large numbers in most
oceans (Romanov, 2002; Couturier et al., 2012). Long line fisheries in the Atlantic Ocean are also
regularly land mobulid species (Beerkircher et al., 2002; Beerkircher et al., 2008; Rey & MuñozChápuli, 1992).
M. alfredi individuals are regularly caught in shark control nets off Australian and South African
coasts (Sumpton et al., 2011; Young, 2001). In Queensland, 93 mobulid rays were caught in shark
control nets between 1992 and 2008 with a mortality rate of 41% for manta rays (Sumpton et al.,
2011).
Other Threats
Other threats such as entanglement in marine debris, boat strikes, water pollution, habitat
degradation, and irresponsible tourism practises impact this species ( Marshall et al. 2011a;
Couturier et al., 2012 ).
Manta rays become entangled in marine debris such as mooring lines and lost fishing lines (Deakos
et al., 2011; Marshall & Bennett, 2010), including in Australian waters (XXXX XXXX unpub. data). In
Maui, Hawaii 10% of the M. alfredi population have amputated or non-functioning cephalic fins
likely caused by monofilament fishing line entanglement (Deakos et al. 2011). These injuries are
likely to impend on the overall fitness and survival.
This issue directly relates to the Key Threatening Process within the Environmental Protection and
Biodiversity Conservation (EPBC) Act: “Injury and fatality to vertebrate marine life caused by
ingestion of, or entanglement in, harmful marine debris” (Commonwealth of Australia, 1999).
High concentrations of heavy metals such as platinum, mercury and arsenic are present in manta
ray tissues (Essumang, 2009; Essumang, 2010). The effects of the heavy metals on the health of the
species remain unknown (Couturier et al., 2012).
While tourism can be beneficial for sustainable use of M. alfredi, rapid and unmanaged growth can
be detrimental to the health and behaviour of individuals (Anderson et al., 2011; Deakos et al.,
2011; Marshall et al.2011). The presence of a large number of divers in the water can have a
negative effect on individual’s behaviour (Anderson et al., 2011), and fitness (i.e. collision with
divers, touching by divers, disruption of normal feeding and cleaning behaviours). In addition, the
potential for boat strikes is more frequent when numerous boats, needed to carry divers and
snorkelers, are occurring in the same area. Manta rays in the Maldives have been observed
carrying injuries resulting from boat interaction, although the number of fatalities remains
unknown (Anderson et al., 2011; XXXX XXXX Pers. comm).
14. POTENTIAL THREATS
Identify any POTENTIAL threats to the species.
The ingestion of plastic debris by marine species has been well documented as causing fatalities,
ulcerations, intestinal blockages, malnutrition and internal perforation (Boerger et al., 2010;
Mascarenhas et al., 2004). Micro-plastic debris is of particular concern as it is of a similar size to
the zooplankton, and can weigh up to six times more (Moore et al., 2001). Manta rays are filterfeeders and are most likely unable to discriminate between marine debris and zooplankton before
ingestion. The effect of ingested micro-plastic on manta rays remains unknown. This threat is
related to the listed key threatening process within the Environmental Protection and Biodiversity
Conservation (EPBC) Act: “Injury and fatality to vertebrate marine life caused by ingestion of, or
entanglement in, harmful marine debris” (Commonwealth of Australia, 1999).
Climate Change:
M. alfredi are likely to be significantly impacted by loss of climatic habitat caused by anthropogenic
emissions of greenhouse gases, due to the predicted impact this phenomenon will have on the
manta ray food source, the zooplankton (Hays et al., 2005). As oceanic temperatures are expected
to warm by 2–3 °C by 2070 (IPCC, 2007; Poloczanska et al., 2007), the zooplankton community is
likely to respond both globally and locally in terms of changes in abundance, timing and
productivity. The migration paths and timing of the species is likely to change as the seasonal
hotspots of zooplankton are altered (Couturier et al., 2012). Searching for new feeding ground is
likely to impact on the fitness of manta rays as individuals may have to swim larger distances, or in
random movement to find new productive areas.
15. THREAT ABATEMENT
Give an overview of recovery and threat abatement/mitigation actions that are underway and/or
proposed.
Potential threat abatement:
Heinrichs et al. (2011) suggest the following actions could be taken in order to provide threat
abatement for Manta spp. including M. alfredi:
1. Trade Moratoriums – Fisheries are notoriously difficult to regulate and enforce regulations
on (Akiba, 1997; Uozumi, 2003). Research suggests that the most effective, single measure
to reduce pressure on mobulids would be an international moratorium on the import and
sale of gill rakers (Heinrichs et al., 2011). The majority of trade takes place within the
Guangzhou region of China and has an estimated economic value of USD$11 Million per
annum (Hilton, 2011). It is also suggested that other governments considering legislation to
protect sharks, including shark fin trade bans, should include manta and mobula rays in
these bills.
2. Consumer Education – Consumer education campaigns could support the call for a
moratorium. Campaigns could inform consumers “of the unproven nature of gill raker tonic
claims, the extreme vulnerability of these animals, and the long-term sustainable value of
keeping them alive” (Heinrichs et al., 2011).
3. International Protections – It is suggested that all range state countries of Mobulids (M.
alfredi included), should propose their listing under either appendices of Convention on
International Trade in Endangered Species of Wild Fauna and Flora (CITES) (Heinrichs et al.,
2011). A CITES listing would be a highly effective conservation measure. This was
considered in 2010 by the US CITES delegation, but wasn’t enacted due to a lack of data on
fisheries and trade.
Additionally, it is suggested that all Regional Fishery Management Organizations (RFMO’s)
enact “no retention” policies for all mobulids taken as bycatch (Heinrichs et al., 2011).
Currently no RFMOs utilise policies that protect manta and mobula rays.
4. Range State Protections – Range state regulations prohibiting the killing and trade of
mobulids must be pursued (Heinrichs et al., 2011). Protection initiatives should be initially
focuses on the largest fisheries where mobulids occur, including Indonesia, Sri Lanka, India
and Peru, as well as Mozambique and other African countries. Protection of critical habitats
is suggested, along with regulations based on seasonal aggregations.
5. Eco-Tourism and Other Economic Alternatives – Vital to conservation initiatives is poverty
alleviation and economic alternatives (Adams et al., 2004). There is a great potential for
long-term sustainable income, for areas where mobulids are hunted, in managed and
responsible eco-tourism (Brightsmith et al., 2008). These initiatives can provide local
community links to species conservation and protection.
6. Enforcement – It is important that enforcement strategies for conservation activities are
enacted and that they are developed with local stakeholders in order to mitigate against
illegal poaching activities (Hilborn et al., 2006).
Existing Conservation Efforts:
Some nations and nation states (table 1.) have passed laws that prohibit the harvest of mobulids
(including M. alfredi). At the last Convention on the Conservation of Migratory Species of Wild
Animals (CMS), M. birostris was added to the treaty, requiring all party states where the species
occurs to provide immediate protection. This addition to the treaty points out the burgeoning
international recognition of the threats to mobulid species and is the first international agreement
to protect any manta ray species (CMS, 2012; Heinrichs et al., 2011).
United States: In 2009, the Governor of Hawaii signed House Bill 366 creating Act 092(09)
establishing criminal penalties and administrative fines for knowingly killing or capturing manta
rays within State waters (Heinrichs et al., 2011; State of Hawaii, 2009).
Pacific Island States: The sale, trade and distribution of ray parts are prohibited by legislation
enacted in Guam in 2011 (Heinrichs et al., 2011; The Federated States of Micronesia, 2011). This
legislation applies to the Federated States of Micronesia, Palau, the Republic of the Marshall
Islands, Guam and the Commonwealth of the Northern Marianas Islands an area of over 4.5 million
square kilometres.
Republic of Maldives: There has been an export ban on all ray species and their parts since 1995
in the Republic of Maldives (International Union for Conservation of Nature, 2012b). Additionally
the Maldivian Government created two Marine Protected Areas (MPA) for the specific protection
of critical Manta Ray habitat of both species in 2009.
Philippines: Due to focused fishing in the Philippines, Manta Rays have become a rare species
(Marshall et al., 2011a). Due to this the Philippines Government banned the fishing of Manta Rays
in 2003.
Yap: A ~13,000 square kilometre MPA was created in Yap in 2008, specifically for the protection of
Manta Rays (Heinrichs et al., 2011; International Union for Conservation of Nature, 2012b).
Western Australia: Only M. birostris is explicitly protected from any fishing and disturbance or
harassment and then, only within marine parks (The Government of Western Australia, 1994). As
the species classifications are out of date, the Fish Resources Management Act 1994 does not
recognise the two distinct manta ray species, as such M. alfredi are not protected (The
Government of Western Australia, 1995).
Surveys and Monitoring
16. DISTINCTIVENESS
Give details of the distinctiveness of the species.
Is this species taxonomically distinct? Taxonomic distinctiveness is a measure of how unique a
species is relative to other species.
How distinct is this species in its appearance from other species? How likely is it to be
misidentified?
Until recently, the genus Manta was described as monspecific. The genus has now been redescribed with two distinct species the Reef Manta Ray (M. alfredi) and the Giant Manta Ray (M.
birostris) (Marshall et al. 2009), this was further confirmed by genetic evidence (Kashiwagi et al., in
press). Both species occur worldwide, with some regional populations being sympatric and other
allopatric (Kashiwagi et al., 2011).
Due to the taxonomic confusion prior to 2009, historical data can lead to misidentification of the
species referred to where adequate descriptions and photographs are absent (Marshall et al.,
2009). Given this, care should be taken when using historical data to ensure that records are not
referring to M. birostris. Two colour morphs occur in both species; melanistic (black) and leucistic
(white) (Marshall et al., 2009). This can contribute to further difficulty in differentiating between
the species where close examination is not possible and may continue to be a source of error in
future studies and surveys (Marshall et al., 2009).
Additionally, manta rays can often be confused with Mobula species (commonly called devil rays)
due to close morphological resemblance and similar life history aspects, such as planktonic
feeding, reproduction rate and mode, size and circumglobal habitation (White et al., 2006). Figure
6 shows the similarities between the distinct species. Care must be taken to ensure that reports
and surveys are of the correct genus and professional advice should be sought when identifying
individuals (Marshall et al., 2011a).
17. DETECTABILITY
Give details of the detectability of the species.
Provide information on how easy the species is to detect and the ease in which it has/can be
surveyed.
 If relevant, provide information on when and how surveys should be conducted, for example:
o Recommended methods
o Season, time of day, weather conditions
o Length, intensity and pattern of search effort
o Limitations and whether or not the method is accepted by experts
o Survey-effort guide
o Methods for detecting the species.
Manta rays have a great eco-tourism potential, due to their charismatic nature. This is especially
relevant in coastal and developing countries where their presence can be used to generate
substantial economic gains (Anderson et al., 2010). As the species tend to aggregate with
predictability, they can be easy to find and approach by tourists and tourism operators. The
popularity of these species has contributed to an increase in field research at aggregation sites. An
important feature of the species, an individual pigmentation pattern on their ventral surface,
allows for photographic identification of individuals. This method of identification has provided
high quality information regarding the species ecology and biology (Kashiwagi et al., 2010, 2011;
Marshall & Bennett, 2010a, b; Couturier et al., 2011; Deakos et al., 2011; Marshall et al., 2011c).
Methods of detection (Couturier et al., 2012):
Photographic-Identification and citizen science:
Continuous effort by the diving community and research project currently exist to survey and
monitor the populations of manta ray around Australia. Professional and recreational divers are
able to submit their photos and sighting records of manta rays to the current manta ray research
project and contribute to the data collection. This method is recognised by the scientific
community and has been used by other manta research programs around the world and provided
key information on manta ray biology and ecology (Kashiwagi et al., 2010, 2011; Marshall &
Bennett, 2010a, b; Couturier et al., 2011; Deakos et al., 2011; Marshall et al., 2011c). Photographic
evidence is analysed after being gathered by divers, including professionals, amateurs and tourists.
The online global manta ray data base ECOCEAN MantaMatcher allows for sighting reports of
manta rays with photographic evidence around the world (ECOCEAN Manta Matcher, 2012).
Limitations: Most photo-ID databases are limited to a particular aggregation area, and thus only
have a limited capacity to answer questions associated with the large-scale movements of manta
rays (Couturier et al., 2012).
Acoustic telemetry (Couturier et al., 2012):
This technique allows us to understand the habitat use of a particular site by manta rays. In
eastern Australia arrays of receivers are placed all along the coast by several research projects (e.g.
AATAMS), allowing the monitoring of tagged manta ray movements along the coast.
Limitation: only a small number of individuals (i.e. number of individual equipped with acoustic
tags) can be monitored. The tag attachments generally only last up to 1 year, thus, regular tagging
campaigns must be undertaken to maintain the flow of data on the population.
This method is widely used by experts within the field of animal tracking with numerous
publications are available (e.g. Heupel et al. 2006). Two studies using this technique on M. alfredi
are available in the scientific literature (Dewar et al., 2008; van Dukiken 2010).
Satellite telemetry (Couturier et al., 2012):
Satellite tags are attached to manta rays for about 3 months before they automatically detach.
Data collected by these tags includes: swimming depth, light intensity, surrounding temperature
and geo-location.
This technique provides information on the depth at which the species is likely to occur during the
day and at night. What temperature the animal has been exposed to and what route the individual
has been swimming to go from one point to another. Several studies of M. alfredi movement
ecology using this technique are underway (XXXX XXXX unpubl. data).
Limitations: Only a limited number of tags can be deployed (limited by cost of the tag and number
of individual available during tagging campaign). The tag is only deployed for a short period of time
on the animal.
18. SURVEYS
Provide information on survey effort to date, and any ongoing/proposed monitoring programs.
In eastern Australia: Surveys of the manta ray population in this area involved both researchers
and the diving-community since 2007 (Couturier et al. 2011; XXXX XXXX unpub.data). This effort
will continue in the future and increase with the rise of public awareness on manta ray research
through documentaries, public talks and researcher- directly engaging with the community.
In Western Australia: surveys of the manta population at this location have existed since 2004.
Both researchers and the public are involved in the data collection.
Global Surveys: Table 2 lists studies that have occurred both nationally and internationally, from
Kashiwagi et al. 2011.
While M. alfredi has a circumglobal distribution, recorded surveys of the species are not common
(Couturier et al., 2011). Table 2 lists studies that have occurred both nationally and internationally.
Note that many of these study started prior to the species split in 2009 (Marshall and Bennett,
2009) and it is now recognised that they are monitoring either M. alfredi, M. birostris or in some
locations, both species.
Indigenous Values
19. INDIGENOUS CULTURAL SIGNIFICANCE
Is the species known to have cultural significance for Indigenous groups within Australia? If so, to
which groups? Provide information on the nature of this significance if publicly available.
There is little information available about the cultural significance of manta rays to Indigenous
Australians. However it is known that Aboriginal and Torres Strait Islanders do harvest the species
for consumption and use biological indicators to select which individuals are fit for consumption
(reefED, 2012).
20. FURTHER INFORMATION
Identify relevant studies or management documentation that might relate to the species (e.g.
research projects, national park management plans, recovery plans, conservation plans, threat
abatement plans, etc.).
Research projects within Australian waters:
Mike Bennett et al – ARC Linkage project: LP1110712: “An integrated examination of the drivers of
movements of large filter-feeding organisms of high ecotourism value: a case study” – The
University of Queensland
Kathy Townsend et al – Earthwatch research project; “Project Manta” – The University of
Queensland
Lydie Couturier_ PhD thesis due by end 2012: “Population ecology and biology of Manta alfredi in
eastern Australia” – The University of Queensland
Fabrice Jaine – PhD Project due by end 2012: “Movements of planktivorous marine megafauna and
ocean dynamics: A case study of east Australian manta rays” – The University of Queensland
Nathalie Verlinden – Honours project – “Seasonal variation of zooplankton nutritional quality in
manta ray (Manta alfredi) aggregation areas” – The University of Queensland
Frazer McGregor – PhD Thesis: “Ecology and movements of manta rays of Western Australia” Murdoch University
Richard Fitzpatrick – research project – “Caitlin Seaview Survey - The Mega-Fauna Survey team” –
The University of Queensland
21. REFERENCE LIST
Please list key references/documentation you have referred to in your nomination.
Adams, WM, Aveling, R, Brockington, D, Dickson, B, Elliott, J, Hutton, J, Roe, D, Vira, B & Wolmer,
W 2004, 'Biodiversity conservation and the eradication of poverty' Science, vol. 306, no.
5699, pp. 1146.
Akiba, O 1997, 'Policy issues, and challenges in Canadian management of the Atlantic fisheries'
Environmental Conservation, vol. 24, no. 02, pp. 159-167.
Alava, MNR, Dolumbaló, ERZ, Yaptinchay, AA & Trono, RB 2002 Fishery and trade of whale sharks
and manta rays in the Bohol Sea, Philippines. In Elasmobranch Biodiversity, Conservation
and Management: Proceedings of the International Seminar and Workshop. Sabah,
Malaysia, International Union for Conservation of Nature.
Alexander, R. L. 1996. Evidence of brain-warming in the mobulid rays, Mobula tarapacana and
Manta birostris (Chondrichthyes: Elasmobranchii: Batoidea: Myliobatiformes). Zoological
Journal of the Linnean Society 118, 151-164.
Anderson, RC, Adam, MS & Goes, JI 2011, 'From monsoons to mantas: seasonal distribution of
Manta alfredi in the Maldives' Fisheries Oceanography, vol. 20, no. 2, pp. 104-113.
Australian Government (2009). The direct value of sharks to the marine tourism industry. Available
at http://www.rrrc.org.au/publications/downloads/value_of_sharks.pdf [Accessed 22
March 2012].
Banerjee, K, Ghosh, R, Chowdhury, M, Ghosh, S, Homechaudhuri, S & Mitra, A 2008, 'Spatial and
temporal variation of elasmobranchs in and around Indian sundarbans' Zoological Research
in Human Welfare, vol. na, no. na, pp. 117-125.
Barnes, RH 2005, 'Indigenous use and management of whales and other marine resources in east
flores and lembata, Indonesia' Senri Ethnological Studies, vol. 67, no. na, pp. 77-85.
Beerkircher, LR, Cortes, E & Shivji, M 2002, 'Characteristics of shark bycatch observed on pelagic
longlines off the Southeastern United States, 1992-2000' Marine Fisheries Review, vol. 64,
no. 4, pp. 40-49.
Beerkircher, LR, Cortés, E & Shivji, MS 2008, 'Case study: Elasmobranch bycatch in the pelagic
longline fishery off the southeastern United States, 1992–1997' Sharks of the Open Ocean,
vol. na, no. na, pp. 242-246.
Boerger, CM, Lattin, GL, Moore, SL & Moore, CJ 2010, 'Plastic ingestion by planktivorous fishes in
the North Pacific Central Gyre' Marine pollution bulletin, vol. 60, no. 12, pp. 2275-2278.
Brightsmith, DJ, Stronza, A & Holle, K 2008, 'Ecotourism, conservation biology, and volunteer
tourism: A mutually beneficial triumvirate' Biological Conservation, vol. 141, no. 11, pp.
2832-2842.
Clark, TB 2010a, Abundance, home range, and movement patterns of manta rays (Manta alfredi,
M. birostris) in Hawai'i, University of Hawai'i, Mãnoa.
Cliff, G, Dudley, SFJ, Ryan, PG & Singleton, N 2002, 'Large sharks and plastic debris in KwaZuluNatal, South Africa' Marine and Freshwater Research, vol. 53, no. 2, pp. 575-581.
CMS 2012, Convention on Migratory Species, viewed 29 February, 2012, http://www.cms.int/.
Commonwealth of Australia 1999, Environment Protection and Biodiversity Conservation Act 1999,
Commonwealth of Australia,
Couturier, LIE, Jaine, FRA, Townsend, KA, Weeks, SJ, Richardson, AJ & Bennett, MB 2011,
'Distribution, site affinity and regional movements of the manta ray, Manta alfredi (Krefft,
1868), along the east coast of Australia' Marine and Freshwater Research, vol. 62, no. 6, pp.
628-637.
De Rosemont, M 2008 Observation and sighting description of the Manta birostris, in BoraBora
Island (French Polynesia – South Pacific). IN Donnelly, M (Ed.) Joint Meeting of
Ichthyologists and Herpetologists. Montreal, Canada.
Deakos, M. H. 2010a. Paired-laser photogrammetry as a simple and accurate system for measuring
the body size of free-ranging manta rays Manta alfredi. Aquatic Biology 10, 1–10.
Deakos, MH, Baker, JD & Bejder, L 2011, 'Characteristics of a manta ray Manta alfredi population
off Maui, Hawaii, and implications for management' Marine Ecology-Progress Series, vol.
429, no. pp. 245-260.
Dewar, H 2002, Preliminary report: Manta harvest in Lamakera, Pfleger Institue of Environmental
Research and the Nature Conservancy, Oceanside.
Dewar, H, Mous, P, Domeier, M, Muljadi, A, Pet, J & Whitty, J 2008, 'Movements and site fidelity of
the giant manta ray, Manta birostris, in the Komodo Marine Park, Indonesia' Marine
Biology, vol. 155, no. 2, pp. 121-133.
Ebert, D. A. (2003). Sharks, Rays and Chimaeras of California. Berkeley, CA: University of
California Press.ECOCEAN Manta Matcher 2012, Overview, viewed 7 March, 2012,
http://www.mantamatcher.org/.
Edwards, M & Richardson, AJ 2004, 'Impact of climate change on marine pelagic phenology and
trophic mismatch' Nature, vol. 430, no. 7002, pp. 881-4.
Essumang, DK 2009, 'Analysis and Human Health Risk Assessment of Arsenic, Cadmium, and
Mercury in Manta Birostris (Manta Ray) Caught Along the Ghanaian Coastline' Human and
Ecological Risk Assessment, vol. 15, no. 5, pp. 985-998.
Essumang, DK 2010, 'First Determination of the Levels of Platinum Group Metals in Manta birostris
(Manta Ray) Caught Along the Ghanaian Coastline' Bulletin of environmental contamination
and toxicology, vol. 84, no. 6, pp. 720-725.Fertl, D., Acevedo-Gutierrez, A. & Darby, F. L.
(1996). A report of killer whales (Orcinus orca) feeding on a carcharhinid shark in Costa
Rica. Marine Mammal Science 12, 606–611.
Graham, R, Hickerson, E, Castellanos, D & Nuttall, M. 2008 Site fidelity and movements of juvenile
manta rays in the Gulf of Mexico. IN Donnelly, M (Ed.) Joint Meeting of Ichthyologists and
Herpetologists. Montreal, Canada.
Hays, GC, Richardson, AJ & Robinson, C 2005, 'Climate change and marine plankton' Trends in
Ecology & Evolution, vol. 20, no. 6, pp. 337-344.
Heinrichs, S, O’Malley, M, Medd, H & Hilton, P 2011, The Global threat to Manta and Mobula Rays,
New York.
Hilborn, R, Arcese, P, Borner, M, Hando, J, Hopcraft, G, Loibooki, M, Mduma, S & Sinclair, ARE
2006, 'Effective Enforcement in a Conservation Area' Science, vol. 314, no. 5803, pp. 1266.
Hilton, P 2011, East Asia Market Investigation - Manta Ray of Hope,
Hoegh-Guldberg, O 1999, 'Climate change, coral bleaching and the future of the world's coral
reefs' Marine and Freshwater Research, vol. 50, no. 8, pp. 839-866.
Hoegh-Guldberg, O, Mumby, PJ, Hooten, AJ, Steneck, RS, Greenfield, P, Gomez, E, Harvell, CD, Sale,
PF, Edwards, AJ & Caldeira, K 2007, 'Coral reefs under rapid climate change and ocean
acidification' Science, vol. 318, no. 5857, pp. 1737.
Homma, K, Maruyama, T, Itoh, T, Ishihara, H & Uchida, S 1997 Biology of the manta ray, Manta
birostris Walbaum, in the Indo-Pacific. 5th Indo-Pacific Fish Conference. Noumea, France:
Ichthyological Society of France.
Hughes, TP, Baird, AH, Bellwood, DR, Card, M, Connolly, SR, Folke, C, Grosberg, R, Hoegh-Guldberg,
O, Jackson, JBC & Kleypas, J 2003, 'Climate change, human impacts, and the resilience of
coral reefs' Science, vol. 301, no. 5635, pp. 929.
International Union for Conservation of Nature 2012a, IUCN Red List of Threatened Species, viewed
February 23, 2012, http://www.iucnredlist.org/.
International Union for Conservation of Nature 2012b, Manta alfredi, viewed February 23, 2012,
http://www.iucnredlist.org/.
IPCC 2007, Fourth Assessment Report of the Intergovernmental Panel on Climate Change,
Intergovernmental Panel on Climate Change, Geneva.
Ishihara, H & Homma, K 1995, 'Manta rays in the Yaeyama Islands' Shark News, vol. 5, no. 3, pp.
Kashiwagi, T, Marshall, A & Bennett, M 2008, DNA evidence for cryptic species boundaries within
Manta birostris?, Montreal.
Kashiwagi, T., Ito, T., Ovenden, J., Bennett, M., 2008. Population characteristics of Manta birostris
observed in Yaeyama, Okinawa, Japan, 1987 - 2006. . Abstracts of Joint Meeting of
Ichthyologists and Herpetologists, Montreal, Quebec, 2008 235-236.
Kashiwagi, T., Ito, T., Sato, F., 2010. Occurences of reef manta ray, Manta alfredi, and giant manta
ray, M. birostris, in Japan, examined by photographic records. Report of Japanese Society
for Elasmobranch Studies 46, 20-27.
Kashiwagi, T, Marshall, AD, Bennett, MB & Ovenden, JR 2011, 'Habitat segregation and mosaic
sympatry of the two species of manta ray in the Indian and Pacific Oceans, Manta alfredi
and M. birostris.' Marine Biodiversity Records, vol. 4, no. pp. e53.
Kazunari, Y, Fumihiko, S & Tomoko, T 1999, 'Observations of mating behavior of the manta
ray,Manta birostris,at the Ogasawara Islands,Japan' Ichthyological research, vol. 46, no. 3,
pp. 289-296.
Kitchen-Wheeler, AM 2010, 'Visual identification of individual manta ray (Manta alfredi) in the
Maldives Islands, Western Indian Ocean' Marine Biology Research, vol. 6, no. 4, pp. 351363.
Law, M 2010 The twister of mantas. Ocean Geographic. Ocean Geographic Society.
Luiz, OJ, Balboni, AP, Kodja, G, Andrade, M & Marum, H 2009, 'Seasonal occurrences of Manta
birostris (Chondrichthyes: Mobulidae) in southeastern Brazil' Ichthyological research, vol.
56, no. 1, pp. 96-99.
Manta ID Palau, 2012, Biology and Behavior, viewed 21 March, 2012,
http://www.mantaidpalau.org/biology-behavior.html.
Marshall, A., Kashiwagi, T., Bennett, M. B., Deakos, M. H., Stevens, G., McGregor, F., Clark, T.,
Ishihara, H. & Sato, K. 2011a. Manta alfredi. In IUCN Red List of Threatened Species.
Version 2011. 1. Available at www.iucnlist.org (accessed 3 February 2011).
Marshall, A, Dudgeon, C & Bennett, M 2011b, 'Size and structure of a photographically identified
population of manta rays Manta alfredi in southern Mozambique' Marine Biology, vol. 158,
no. 5, pp. 1111-1124.
Marshall, AD & Bennett, MB 2010a, " Reproductive ecology of the reef manta ray Manta alfredi in
southern Mozambique". Journal of Fish Biology 77, 169–190.
Marshall, AD & Bennett, MB 2010b, 'The frequency and effect of shark-inflicted bite injuries to the
reef manta ray Manta alfredi' African Journal of Marine Science, vol. 32, no. 3, pp. 573-580.
Marshall, AD, Compagno, LJV & Bennett, MB 2009, 'Redescription of the genus Manta with
resurrection of Manta alfredi (Krefft, 1868)(Chondrichthyes; Myliobatoidei; Mobulidae)'
Zootaxa, vol. 2301, pp. 1-28.
Mascarenhas, R, Santos, R & Zeppelini, D 2004, 'Plastic debris ingestion by sea turtle in Paraiba,
Brazil' Marine pollution bulletin, vol. 49, no. 4, pp. 354-355.
McGregor, F 2012 Known manta sighting areas along WA coast. IN Althor, G (Ed.).
McGregor, F, Van Keulen, M, Waite, A & Meekan, M 2008 Foraging Ecology and Population
Dynamics of the Manta Ray, Manta birostris in Lagoonal Waters of Ningaloo Reef, Western
Australia. Joint Meeting of Ichthyologists and Herpetologists, Montreal, Canada.
Mohanraj, G, Rajapackiam, S, Mohan, S, Batcha, H & Gomathy, S 2009, 'Status of elasmobranchs
fishery in Chennai, India' Asian Fisheries Science, vol. 22, no. 2, pp. 607-615.
Moore, CJ, Moore, SL, Leecaster, MK & Weisberg, SB 2001, 'A comparison of plastic and plankton
in the North Pacific central gyre' Marine pollution bulletin, vol. 42, no. 12, pp. 1297-1300.
Murphy, G 1995 Yap's magnificent mantas!: Up close and personal. Skin Diver. Los Angeles, United
States, Los Angeles, Petersen Publishing Company.
Nair, RJ 2003, 'Targeted shark fishery in Kerala' Marine Fisheries Information Service Technical and
Extension Series, vol. 176, no. na, pp. 8-9.
Notarbartolo di Sciara, G 1988, 'Natural history of the rays of the genus Mobula in the Gulf of
California' U S Fish and Wildlife Service Fishery Bulletin, vol. 86, no. na, pp. 45-66.
Poloczanska, ES, Babcock, RC, Butler, A., Hobday, AJ, Hoegh-Guldberg, O, Kunz, TJ, Matear, R,
Milton, D, Okey, TA & Richardson, AJ 2007, 'Climate change and Australian marine life'
Oceanography and Marine Biology, vol. 45, no. pp. 407.
ReefED, 2012, Cultural Connections, viewed 21 March, 2012,
http://www.reefed.edu.au/home/students/web_quest/save_our_sharks/cultural_connecti
ons.
Rey, JC & Muñoz-Chápuli, R 1992, 'Intra and interspecific association of large pelagic fishes inferred
from catch data of surface longline' Environmental biology of fishes, vol. 35, no. 1, pp. 95103.
Richardson, AJ & Schoeman, DS 2004, 'Climate Impact on Plankton Ecosystems in the Northeast
Atlantic' Science, vol. 305, no. 5690, pp. 1609-1612.
Romanov, EV 2002, 'By-catch in the tuna purse-seine fisheries of the western Indian Ocean.'
Fishery Bulletin, vol. 100, no. na, pp. 90-105.
Selkoe, KA, Halpern, BS, Ebert, CM, Franklin, EC, Selig, ER, Casey, KS, Bruno, J & Toonen, RJ 2009, 'A
map of human impacts to a “pristine” coral reef ecosystem, the Papahānaumokuākea
Marine National Monument' Coral Reefs, vol. 28, no. 3, pp. 635-650.
State of Hawaii 2009 Act 092. IN Representatives, Ho (Ed.) A bill for an Act. Hawaii, State of Hawaii.
Sumpton, WD, Taylor, SM, Gribble, NA, McPherson, G. & Ham, T. 2011, 'Gear selectivity of largemesh nets and drumlines used to catch sharks in the Queensland Shark Control Program'
African Journal of Marine Science, vol. 33, no. 1, pp. 37-43.
The Federated States of Micronesia 2011, A resolution on the 15th Micronesian Executive Cheifs
Summit, The Federated States of Micronesia, Palikir.
The Government of Western Australia 1994, Fish Resources Management Act 1994, The
Government of Western Australia.
The Government of Wester Australia 1995, Fish Resources Management Regulations 1995, The
Government of Western Australia.
Uozumi, Y 2003, 'Historical perspective of global billfish stock assessment' Marine and Freshwater
Research, vol. 54, no. 4, pp. 555-565.
van Duinkerken, D. I. (2010). Movements and site fidelity of the reef manta ray, Manta alfredi,
along the coast of southern Mozambique. Master Thesis, Utrecht University, Utrecht,
Netherlands.
Visser, I 2003, 'New observations and a review of killer whales (Orcinus orca) sightings in Papua
New Guinea waters' Aquatic Mammals, vol. 29, no. 1, pp 150-172.
Webster, C 2009, 'J.E.P. Cyrino, D.P. Bureau, B.G. Kapour (eds): Feeding and digestive functions of
fishes' Reviews in Fish Biology and Fisheries, vol. 19, no. 2, pp. 261-263.
White, WT, Clark, TB, Smith, WD & Bizzarro, JJ 2006. Mobula japanica. In IUCN Red List of
Threatened Species. Version 2011.2. Available at www.iucnlist.org (accessed 21 March
2011).
White, WT, Giles, J, Dharmadi, Potter IC 2006, 'Data on the bycatch fishery and reproductive
biology of mobulid rays (Myliobatiformes) in Indonesia' Fisheries Research, vol. 82, no. 1-3,
pp. 65-73.
Whitley, GP 1936. The Australian devil ray, Daemomanta alfredi (Krefft), with remarks on the
Superfamily Mobuloidae (Order Batoidei). Australian Zoologist 8, 164-188.
Wourms, JP 1977, 'Reproduction and Development in Chondrichthyan Fishes' American Zoologist,
vol. 17, no. 2, pp. 379-410.
Yano, K, Sato, F & Takahashi, T 1999, 'Observations of mating behavior of the manta ray, Manta
birostris, at the Ogasawara Islands, Japan' Ichthyological research, vol. 46, no. 3, pp. 289296.
Young, N 2001 An analysis of the trends in by-catch of turtle species, angelsharks and batoid
species in the protective gillnets off KwaZulu-Natal, South Africa. Reading, University of
Reading.
Zeeberg, JJ, Corten, AHM & de Graaf, E 2006, 'By-catch and release of pelagic megafauna in
industrial fisheries off Northwest Africa' Fisheries Research, vol. 78, no. na, pp. 185-196.
22. APPENDIX
Please place here any figures, tables or maps that you have referred to within your nomination.
Alternatively, you can provide them as an attachment.
Figure deleted due to copyright
Figure 1 – M. alfredi is a large conspicuous, elasmobranch fish (Couturier et al., 2011).
Figure deleted due to copyright
Figure 2 –Known distributions of both Manta species. M.alfredi (in orange), Manta birostris (in blue) and both species (in green)
(Couturier et al., 2012).
Figure deleted due to copyright
Figure 3 –Map of known extent of occurrence for Manta alfredi within Australian waters stretching from Albany in WA, around
to Sydney Harbour in NSW. A total of 6,780,364 km2. Paie blue line indicates areas of occurrence based on current information.
Figure deleted due to copyright
Figure 4 –Area of occupancy pf Manta alfredi along the East Australian coastline and the locations used to calculate the
estimated area of Manta alfredi distribution using measuring CSIRO software “ImageJ” (adapted from: Couturier et al., 2011)
Figure deleted due to copyright
Figure 5 –Manta ray sightings and population estimates along the Western Australian coastline and the locations used to
calculate the estimated area of Manta alfredi distribution using measuring CSIRO software “ImageJ”. Green markings are
sightings of M. birostris and blue markings are M. alfredi (McGregor, 2012).
Figure deleted due to copyright
Figure 6 – The known aggregation sites for M. alfredi in WA and Indonesia are similar to known migration distances of the
species. It is likely that the species migrates into Indonesian waters where they are threatened by directed fishing activities. Red
line = 500km, the current known distance migrated for this species (Couturier et al 2011)
Figure deleted due to copyright
Figure 7 – Manta rays share similar morphologies and life histories with Devil Rays. As such, professional advice should be sought
when making an identification of an individual (Adapted from Manta ID Palau, 2012)
Tables
Table 1 - International Manta Ray Conservation Measures (adapted from: Heinrichs et al., 2011)
LOCATION
Australia (Western)
Ecuador
Guam, USA
Territory
Honduras
Indonesia – Raja
Ampat
Maldives
Mexico
Philippines
Revillagigedo
Islands
USA – Florida
USA - Flower
Garden Banks
USA – Hawaii
Yaeyama Islands,
Japan
SPECIES
Mantas
Mantas
/Mobulas
Mantas
LEGISLATION / CONSERVATION MEASURE
Fishing; harassment prohibited in marine parks
Ecuador Official Policy 093, 2010
All
elasmobranche
s
Mantas
/Mobulas
Mantas
Manta/mobula
spp.
Mantas
Full ban on fishing elasmobranches 2010
Bill 44-31 prohibiting sale/trade in ray parts 2011
Regency Bupati Decree October 2010
Mantas
Exports of all ray products banned 1995
NOM-029-PESC-2006 Prohibits harvest and
sale
FAO 193 1998 Whale Shark and Manta Ray
Ban
Marine Protected Area
Mantas
Mantas
FL Admin Code 68B-44.008 – no harvest
US Dept of Commerce 2010
Mantas
Mantas
H.B. 366 2009 – no harvest or trade
Marine Protected Area
Yap (FSM)
Mantas
Manta Ray Sanctuary and Protection Act 2008
Table 2 – Recorded surveys of Manta Rays locally and globally (adapted from Kashiwagi et al., 2011).
LOCATION
East Australian Coast
West Australian Coast
Hawaii
Japan
Tahiti
Mozambique
the Maldives
Indonesia
Mexico
Brazil
ASSOCIATED LITERATURE
(Couturier et al., 2011)
(McGregor et al., 2008)
(Clark, 2010a; Deakos et al., 2011)
(Homma et al., 1997; Ishihara & Homma, 1995;
Yano et al., 1999; Kashiwagi et al., 2010)
(De Rosemont, 2008)
(Marshall et al., 2011)
(Kitchen-Wheeler, 2010)
(Dewar et al., 2008)
(Graham et al., 2008)
(Luiz et al., 2009)