ArticlePDF Available

Characterization of the trade in manta and devil ray gill plates in China and South-east Asia through trader surveys: The Manta and Devil Ray Gill Plate Trade

Authors:

Abstract and Figures

Dried gill plates from manta and devil rays, some of the world's most biologically vulnerable fishes, have become a valued commodity in Asian dried-seafood and traditional Chinese medicine markets. This trade is a primary driver of fisheries, which have led to declines in many mobulid populations. With no reliable trade statistics and scarce data on mobulid fisheries, this study estimates the number and species of mobulids required to supply this trade, and investigates the consumers and suppliers involved and drivers of demand. Following preliminary market research, 525 trader surveys were conducted in Hong Kong, Singapore, Macau, Taiwan, and southern China. Guangzhou, China was identified as the centre of the trade accounting for 99% of total estimated market volume of 60.5 tons of dried gill plates in 2011, increasing to 120.5 tons by 2013. The estimated number of mobulids converted from tons of gill plates more than doubled over the period to 130 000, comprising 96% devil rays, Mobula japanica, Mobula thurstoni, and Mobula tarapacana, and 4% Manta spp. By 2015 the Guangzhou market had declined sharply, reportedly due to conservation campaigns and government policies. However Hong Kong's gill plate sales increased dramatically between 2011 and 2015. China, Indonesia, Vietnam, Sri Lanka, and India were reported most frequently as gill plate sources. Vendors recommend gill plates (trade name pengyusai) for ailments ranging from acne to cancer and as a general health tonic. While pengyusai is a new addition to traditional Chinese medicine literature and is rarely prescribed by traditional medicine practitioners, it is readily available over the counter and aggressively marketed by vendors. Working in concert with consumer demand reduction efforts, increased measures to restrict mobulid fisheries and trade are recommended to prevent further population declines of these highly vulnerable species. Copyright
Content may be subject to copyright.
Characterization of the trade in manta and devil ray gill plates in
China and South-east Asia through trader surveys
MARY P. OMALLEY
a,b,
*, KATHY A. TOWNSEND
c
, PAUL HILTON
a,b
, SHAWN HEINRICHS
a,b
and
JOSHUA D. STEWART
b,d
a
WildAid, San Francisco, CA, USA
b
Manta Trust, UK
c
School of Biological Sciences, Moreton Bay Research Station, The University of Queensland
d
Scripps Institution of Oceanography, CA, USA
ABSTRACT
1. Dried gill plates from manta and devil rays, some of the worlds most biologically vulnerable shes, have
become a valued commodity in Asian dried-seafood and traditional Chinese medicine markets. This trade is a
primary driver of sheries, which have led to declines in many mobulid populations.
2. With no reliable trade statistics and scarce data on mobulid sheries, this study estimates the number and
species of mobulids required to supply this trade, and investigates the consumers and suppliers involved and
drivers of demand. Following preliminary market research, 525 trader surveys were conducted in Hong Kong,
Singapore, Macau, Taiwan, and southern China.
3. Guangzhou, China was identied as the centre of the trade accounting for 99% of total estimated market
volume of 60.5 tons of dried gill plates in 2011, increasing to 120.5 tons by 2013. The estimated number of
mobulids converted from tons of gill plates more than doubled over the period to 130 000, comprising 96%
devil rays, Mobula japanica,Mobula thurstoni, and Mobula tarapacana, and 4% Manta spp.By 2015 the
Guangzhou market had declined sharply, reportedly due to conservation campaigns and government policies.
However Hong Kongs gill plate sales increased dramatically between 2011 and 2015.
4. China, Indonesia, Vietnam, Sri Lanka, and India were reported most frequently as gill plate sources.
5. Vendors recommend gill plates (trade name pengyusai) for ailments ranging from acne to cancer and as a
general health tonic. While pengyusai is a new addition to traditional Chinese medicine literature and is rarely
prescribed by traditional medicine practitioners, it is readily available over the counter and aggressively
marketed by vendors.
6. Working in concert with consumer demand reduction efforts, increased measures to restrict mobulid sheries
and trade are recommended to prevent further population declines of these highly vulnerable species.
Copyright #2016 John Wiley & Sons, Ltd.
Received 02 March 2015; Revised 22 March 2016; Accepted 26 March 2016
KEY WORDS: endangered species; sustainability; sh; shing; ocean
*Correspondence Author: Mary OMalley, WildAid, 744 Montgomery Street, Suite 300, San Francisco, CA 94111, USA. Email: maryomalley@mac.
com
The copyright line was changed on 04 July 2016 since rst publication.
#2016 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons, Ltd.
AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Published online in Wiley Online Library
(wileyonlinelibrary.com). DOI: 10.1002/aqc.2670
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and
distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modications or adaptations are made.
INTRODUCTION
Manta and devil rays (collectively mobulids) have
been increasingly targeted over the past two
decades to supply a growing market for their gills,
which are sold in traditional Chinese medicine
(TCM) and Asian dried-seafood markets (White
et al., 2006b; Camhi et al., 2009; Couturier et al.,
2012). These planktivorous elasmobranchs possess
gill plates, also referred to commonly as gill
rakers, which are rigid sieving pads used to lter
zooplankton from sea water (Cortes et al., 2008;
Paig-Tran et al., 2013). While mobulid meat is
generally not highly valued for human
consumption, the dried gill plates from these
species have recently become a valued commodity
in Chinese and South-east Asian markets (White
et al., 2006b; Rajapackiam et al., 2007; Anderson
et al., 2010; Heinrichs et al., 2011). Similar to the
trades in shark n, rhino horn, and saiga antelope
horn, these specic body parts are worth
substantially more than the rest of the animal
(Cheung, 1995; Milner-Gulland et al., 2003;
Clarke et al., 2007). The gill plates are marketed
under the trade name pengyusai, a remedy
purported to treat a variety of health issues
ranging from acne to cancer (Heinrichs et al., 2011).
Manta and devil rays belong to the Mobulidae
family, which comprises the two species of the genus
Manta and nine species of the genus Mobula
(Couturier et al., 2012). Behavioural characteristics,
such as surface-feeding and aggregating in large
numbers (Bizarro et al., 2006, Valenti and Kyne,
2009; Marshall et al., 2011a, b; Couturier et al.,
2012), combined with overlap of mobulidshabitat
and migratory paths with artisanal and large-scale
commercial sheries (Ward-Paige et al., 2013;
Germanov and Marshall, 2014; Thorrold et al.,
2014; Croll et al., 2015), make these species easily
accessible to shers. These characteristics, in addition
to extremely low reproductive rates (Couturier et al.,
2012), leave mobulid populations exceptionally
vulnerable to mortality from directed sheries and
bycatch with limited capacity to recover from
overshing (Couturier et al., 2012; Dulvy et al.,
2014). Fisheries supplying the Asian dried gill plate
market have been documented in India, Sri Lanka,
Indonesia, Malaysia, the Philippines, Mozambique,
Palestine, and China, and have heavily impacted
many mobulid subpopulations (Alava et al., 2002;
Rajapackiam et al., 2007; Fernando and Stevens,
2011; Heinrichs et al., 2011; Abudaya et al., 2014;
Dent and Clarke, 2015; Lewis et al., 2015). This
escalating threat has led to IUCN Red List
classication of Manta alfredi and Manta birostris as
globally vulnerable to extinction (Marshall et al.,
2011a, b), and Mobula tarapacana,Mobula japanica,
and Mobula thurstoni as vulnerable in South-east
Asia (Clark et al.,2006a,b;Whiteet al., 2006a).
With growing concerns about the stability of
many regional mobulid subpopulations from
increased targeted shing, combined with scarce
reporting of sheries data and no tracking of trade
data (FAO, 2015), there is a need for better
information about the market for gill plates to aid
in conservation and management efforts. This
study is the rst assessment of the mobulid gill
plate trade in southern China and South-east Asia,
and estimates the scale of the trade, determines
market trends and factors driving demand, and
explores the potential implications of current levels
of trade on the conservation of mobulid species.
METHODS
Data collection
Data collection to assess the pengyusai markets
distribution, volume, species composition, and
trends comprised eld research in dried seafood
and TCM markets over four survey periods in
20092010, 2011, 2013, and 2015 and research of
web-based traders in 2014 and 2016. In addition, a
TCM literature review via Internet search and the
Hong Kong University library and interviews with
TCM practitioners in Guangzhou, China,
Singapore, Hong Kong, and Macau were
conducted with assistance from native Mandarin
and Cantonese speakers.
Determination of areas to investigate was made
based on reports and observations from prior
investigations of the shark n trade in China and
South-east Asia, review of previously conducted
wildlife TCM market studies (Vincent, 1997;
Cheung and Dudgeon, 2006; Li et al., 2007), an
Indonesian mobulid shery study (White et al.,
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
2006b), and interviews with traders at mobulid
shery landing sites in Sri Lanka and Indonesia.
In 20092010, prior to initiating the rst market
investigations, a preliminary assessment was
conducted in southern China to identify the key
cities and market districts in which to focus more
extensive surveys. This assessment entailed eight
eld visits to dried seafood and TCM market
areas in Guangdong (primary market centres in
Guangzhou and Shenzhen and secondary markets
including the border area between Guangdong and
Fujian), Hunan, and Hainan Provinces.
In April/May 2011, 283 dried seafood and TCM
businesses were surveyed across Hong Kong,
Singapore, Macau, Taiwan, and Guangzhou,
China. Authors (PH, SH), accompanied by
residents uent in the local dialect and familiar
with the markets in each area, spent several days
surveying the dried seafood and TCM business
districts within each of these locations. The
Guangzhou survey focused on the two key market
areas identied the Qingping Market in the
north of Shamian Island, Liwan District and the
Yide Dry Seafood Market in the Yuexiu District.
Sixty-ve stores were selected in these two areas,
including 32 sellers that were previously observed
or reported to be large specialist pengyusai sellers
or dried seafood/TCM sellers with large quantities
of gills on hand. As the bulk of the remaining
stores in the key market areas appeared to either
not have gills available or were small retail shops
displaying only small quantities, a random sample
of 33 additional stores was chosen to survey in the
areas (buildings/street market sections) with the
highest concentration of pengyusai sellers. In
Singapore and Hong Kong a similar methodology
was applied to select vendors to survey, while the
Macau and Taiwan interviews were conducted
randomly in the districts where dried seafood and
TCM products are sold.
Based on the results of the 2011 surveys, a second
survey was conducted in December 2013 (PH)
solely focused on key market districts in
Guangzhou. In December 2015 follow-up surveys
were conducted in Guangzhou (MO) and Hong
Kong (PH). In 2013 and 2015, following market-
wide visual surveys of key districts for
presence/absence of pengyusai, the vendors
previously identied as major sellers from earlier
surveys were revisited in addition to vendors
observed to be displaying large quantities of gills
during visual surveys, and random samples of
smaller sellers (Table 1).
Research of Internet-based sellers was conducted
via Google searches using the Chinese characters
for pengyusai (). Details including species
offered for sale, prices, reported stock quantities,
business location, reported source region(s), and
recommended uses advertised by each seller were
recorded. In December 2014 a native Mandarin
speaker then contacted the major pengyusai traders,
with majordened as those reporting a physical
store or warehouse location and/or direct
importation of gill plates and advertising available
stock of 25 kg or more.
In all surveys, each business was asked a series of
questions, including: Do you carry pengyusai?,
Can we see it?,How much supply do you have?,
How much does it cost,How much do you sell
per year?,Where do you source it?,What do
your customers purchase pengyusai for?,What
trends are you seeing in supply and demand, and
Can we take a photo?. During the 2014 phone
interviews, additional questions were asked to
sellers reporting China as a source location in
order to gather information on potential mobulid
landing sites in China. As reliability of vendor-
supplied data was a primary concern, researchers
posed as potential buyers to improve
responsiveness (Li et al., 2007; Chow et al., 2014).
To account for potential exaggeration of available
stock, estimates included only visual counts or
quantities that vendors reported to be able to
supply immediately (Li et al., 2007). Interview
responses and observations of visible dried gill
plate stock, including quantities, species, and
prices were recorded.
Data on dried gill plate yields per animal were
obtained from interviews with the manager of a
shark and mobulid processing plant in Puqi,
Zhejiang Province, the city known as the shark
processing centre of southern China (Li et al.,
2012b), investigation of a directed mobulid shery
in Lamakera, East Flores, Indonesia (Lewis et al.,
2015), and review of the Fernando and Stevens
(2011) report on Sri Lankas mobulid sheries and
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
trade. Consultation with these researchers provided
further conrmation of average dried gill plate
yields. Lamakera shermen reported typical dried
gill plate yields of 5 kg per M. birostris (and up to
7 kg from very large mantas) and 2 to 3 kg for M.
tarapacana (Lewis et al., 2015). The Puqi plant
manager reported yields of 2.5 kg dried gills per
500 kg of whole animals. As the Puqi manager
reported dried gill plate yields for M. japanica by
weight rather than number of animals, typical
total weight (TW) per M. japanica was estimated
using the Notarbartolo di Sciara (1988) DW (disc
width) to TW conversion formula as follows: M.
japanica (TW = 4.29 × 10
10
(DW)
3.4
), with typical
DW approximated at 2188 mm, the average of
male and female sizes at maturity for this species
(Notarbartolo di Sciara, 1987). Dried gill plate
yield estimates were then used to convert the
annual sales of dried gill plates in kg for each
species to the estimated total number of animals
required to supply the dried gill plate trade
annually.
Data analysis
Using vendor survey responses and visual stock
counts, low, medium, and high estimates were
calculated for the total volume (in kg) of dried gill
plates sold annually in each survey city. Visual
stock estimates entailed recording the number and
estimated weight of gill plate containers in each
surveyed store by gill plate type. Container
weights were estimated based upon responses from
traders and researchersobservations, and by
weighing several bags to test the accuracy of
estimates (Figure 1). To calculate annual sales
volume estimates for sellers that did not divulge
their sales gures, the median stock quantity to
annual sales volume ratios from sellers who
reported both inventory and annual sales gures
Table 1. Market districts surveyed (including percentage of stores visually surveyed that had pengyusai for sale)
Survey Districts Total estimated stores
1
Visual presence/absence Had PYS Vendors surveyed
3
Guangzhou 2011
2
Qingping 650 265 30 37
Yuexiu 400 250 30 28
Total (12%) 1050 515 60 65
Hong Kong 2011 Sheung Wan 300 180 17 46
Central 30 10 2 22
Cheung Chau 15 5 1 1
Total (10%) 345 195 20 69
Macau 2011 (32%) Central Business District 60 50 16 26
Singapore 2011 Albert Centre 50 50 6 12
Chinatown 40 30 10 30
Victoria Street Wholesale 20 20 2 8
Bencoolen 10 10 2 6
Other 20 10 4 12
Total (20%) 140 120 24 68
Taiwan 2011 Taipei (Di Hwa St.) 11 0 11
Taichung (Wu Chi) 11 0 11
Kaoshiung (San Feng St.) 33 0 33
Total (0%) 55 0 55
Guangzhou 2013 Qingping 653 466 69 43
Yuexiu 433 286 20 17
Total (12%) 1086 752 89 60
Online Sellers 2014 Taobao.com 56 56 56 18
Guangzhou 2015 Qingping 1,611 1,611 59 59
Yuexiu 561 561 18 18
Total (4%) 2172 2172 87 87
Hong Kong 2015 Sheung Wan 300 NA 14 52
Central 30 NA 8 25
Total 22 77
1
Total number of stores in each district refers to estimated number of stores of the type potentially
selling pengyusai (dried seafood, TCM).
2
Presence/absence survey was conducted in 2010.
3
In Guangzhou 2015 surveys, stock counts were done at 87 stores and interviews conducted at 30 stores.
PYS - pengyusai
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
were applied to the stock numbers for the sellers
that did not report annual sales. To estimate total
market volume, annual sales estimates for each
seller were organized by type of seller, and the
percentage of survey coverage by volume was
estimated for each seller type. These market
coverage estimates were then applied to the total
annual volumes from the stores surveyed to
generate overall estimates for the gill plate trade in
each market. Trade volume in Chinese yuan
(CNY) was calculated by multiplying the average
price per kg for each gill type by the estimated
annual sales in kg for each gill type. Historical
exchange rates from April 2011, December 2013,
and December 2015 (www.xe.com) were used to
convert CNY sales to USD. To assess market
trends, vendor-reported trends in supply and
demand were compared across all markets and
years. Estimates of gill plate stock, annual sales
volume, species composition, and prices were
compared across the three Guangzhou surveys.
Analysis of Variance (ANOVA) was used to
identify signicant differences in prices across
survey years and among species (IBM Corp.,
2010). Both Species and Year were considered to
be xed effects and an interaction term was
included between these effects, with the model
equation: Response Variable ~ Species * Year. A
non-parametric KruskalWallis test was used to
identify differences in stocks and sales of gill plates
between years for each species, as these data were
non-normally distributed. All statistical analyses
were conducted in R. As the 2015 Hong Kong
price levels were reported from one large
Figure 1. Stock estimates. Bags/containers of various sizes were weighed and the number of each type per species were counted to estimate stock
amounts. (A) Large bags of Manta spp., M. tarapacana and M. japanica/other gill plates; (B) weighing a small bag of Manta spp. gill plates; (C)
bins with the three different gill plate types; (D) plastic packages of M. tarapacana gill plates. Photos by Paul Hilton (A, B, C), Mary OMalley (D).
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
distributor interviewed, and price data were not
collected from all vendors, analysis of variance
could not be conducted for Hong Kong prices.
Dried gill plates were identied by species using
visual identication characteristics from the
Stevens (2011, 2013) mobulid identication eld
guides. The species composition of stock and sales
volume was estimated through visual stock counts
and seller interviews. For further conrmation of
species identication, photographs of dried
mobulid gill plates of different types and sizes
were later compared with dried gill plate
photographs from the Lamakera shery, Puqi
processing plant, and diagrams provided in
Paig-Tran et al. (2013), in consultation with the
Sri Lanka researchers (G. Stevens, D. Fernando).
RESULTS
Market volume and trends
The 2011 surveys revealed that Guangzhou, China
traded by far the largest volume of gill plates of all
the market cities surveyed, with 99.5% of the
estimated total annual market volume of 60.15 t,
representing CNY 83 million (USD 10.7 million)
in sales. Taiwan was apparently not involved in
the trade, with most businesses surveyed having
never heard of gill plates or pengyusai. Annual gill
plate sales per vendor did not change signicantly
between years for the two main types of Mobula
gill plates identied, M. japanica/other (P= 0.97)
or M. tarapacana (P= 0.29), but gill plate sales
per vendor dropped signicantly between 2011 and
2013 for Manta spp.(P= 0.009). However, the
total estimated market volume from the December
2013 Guangzhou survey was 120.45 t (CNY 176.3
million; USD 29 million), double the 2011
estimate, with large increases in estimated total
annual sales of the two types of Mobula spp. gill
plates and a slight increase for Manta spp.
(Table 2(a)). In 2015 it was not possible to
estimate annual sales for the Guangzhou market,
since most of the large suppliers from previous
surveys were either no longer selling pengyusai or
reported plans to exit the trade after selling off
remaining stock. Total gill plate stocks in 2015
(2.7 t) were down to roughly a third (37%) of 2013
levels (8.1 t) and a little over half (55%) of 2011
levels (5.6 t) (Table 2(b)). However, three of the
vendors interviewed in 2015 still reported selling
large quantities of gill plates, including one that
reported to be selling 6 t per year, with the
majority exported to two large traders in Hong
Kong and one in Macau.
The Hong Kong survey revealed there are two
major traders supplying gill plates to this market.
One located in Sheung Wan (Hong Kong Island)
reported selling between 1 and 2 t per year with a
steady supply of gills primarily from Indonesia
and Sri Lanka, and smaller amounts from the
Table 2. Gill plate market volume estimates
a. Estimated annual gill plate sales volume (KG)
Manta
M.
Tarapacana
M.
japanica
/other Total
Apr 2011 Surveys
Guangzhou 21 876 20 324 17 952 60 152
Singapore 92 64 27 183
Hong Kong 90 9 26 125
Macau 11 7 10 28
Dec 2013
Guangzhou 23 811 42 165 54 493 120469
Dec 2015 Surveys
Guangzhou NA NA NA NA
Hong Kong 1925 875 700 3500
Guangzhou Apr
2011 to Dec 2013
Change %
+9% +107% +204% +100%
Hong Kong Dec
2011 to Dec 2015
Change %
+2039% +9622% +2592% +2700%
b. Estimated gill plate stocks (KG)
Manta
M.
Tarapacana
M.
japanica/
other Total
Apr 2011 Surveys
Guangzhou 1837 1836 1376 5049
Singapore 49 34 15 98
Hong Kong 60 6 17 83
Macau 7 5 6 18
Dec 2013
Guangzhou 1399 3439 2630 7468
Dec 2015 Surveys
Guangzhou 916 799 1,038 2764
Hong Kong NA NA NA NA
Guangzhou Apr
2011 to Dec 2013
Change %
24% +87% +91% +48%
Guangzhou Dec
2013 to Dec 2015
Change %
35% 77% 61% 63%
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Philippines. The Guangzhou trader reported selling
gill plates to both the major traders in Hong Kong,
and reported that the larger customer, located in
Kowloon, purchases 2 t of gill plates per year
from her business. From these reports, 2015
annual market volume for Hong Kong was
roughly estimated at 34 t per year, an increase of
28 times the 2011 market estimate of 125 kg per
year. None of the gill plate vendors had pengyusai
stock on display, but would retrieve a bag of
about 0.6 kg when asked if they carried the
product. The Guangzhou trader reported sourcing
gill plates mainly from Mauritius and Vietnam.
This trader and the large Hong Kong trader
reported a strong preference for large manta gill
plates among Hong Kong and Macau consumers
with mainland Chinese customers generally
preferring the less expensive small devil ray gill
plates.
In Guangzhou, there were approximately 1100
shops in the key market areas in 2011 and 2013,
and 12% had gill plates visibly displayed for sale
in both years. In 2015 researchers counted over
2100 stores in these market areas and 3.4% with
gill plates for sale (Table 1). There were three
main types of gill plate sellers: (1) large suppliers
specializing in gill plates, sh bladders, seahorses,
and puffer sh with very large stock levels; (2)
larger dried seafood/TCM shops with a large
inventory of a range of products; and (3) small
dried seafood/TCM retailers and apothecaries
with limited gill plate stock. The large suppliers
and shops reported importing gills directly from
overseas or purchasing from Chinese ports or
processors and selling to retail shops, restaurants,
and individuals. Small retailers were generally
reluctant to reveal their suppliers, but reported
selling almost exclusively to individuals for
personal use. The large stores kept gill plates in
large bags (approximately 15 kg), while the small
shops displayed stock in various bags, bins, jars,
and plastic packages. In 2011, Guangzhou stores
stocked considerably higher quantities (mean
124 kg SD ± 59) compared with the other cities
(mean 2.9 kg ± 4.2), and reported faster stock
turnover (median of 12× per year). Stock turnover
rates reported by Guangzhou sellers in 2013 were
similar to 2011 (median of 12× to 15×). In
contrast, most stores in Singapore, the next largest
market in 2011, stocked 13 kg, while in Hong
Kong and Macau, all but a few stores carried only
about 0.6 kg, with these inventory levels reported
to last for 6 months to a year. Mean stock
quantities were substantially higher in 2013
(170 kg SD ± 384), with two sellers reporting 1.5
and 2 t of gill plate stock. In 2015 mean stock
levels were down to 36 kg (SD ± 52), considerably
below even 2011 stock levels. Stocks of gill plates
in Guangzhou were statistically different between
years (P<0.0001 for all species).
Market coverage estimates used to calculate total
annual sales estimates were 81% in 2011 and 91% in
2013 for Guangzhou surveys, assuming 100%
coverage of the large specialist sellers, 75%
coverage of large non-specialized sellers, and
excluding small retail shops to avoid double-
counting of retail and wholesale volumes.
Coverage for the other markets in 2011 was
estimated at 66% for Hong Kong, 64% for
Singapore, and 83% for Macau
1
.
The 2014 Internet search revealed 56 sellers
advertising mobulid gill plates via the Chinese online
commerce site, Taobao.com. Most of the sellers were
based in Guangdong Province (Zhanjiang,
Yangjiang, Jiangmen, Foshan, Maoming, and
Guangzhou) with a few from Guangxi Zhuang
Autonomous Region (Beihai and Nanning) and
Hong Kong. Eighteen were identied as major
sellers, and the others appeared to be exclusively
online resellers of a wide range of products.
Interviews conrmed that 11 of the majorsellers
were direct importers or purchased gill plates from
Chinese ports, and 10 of these were located outside
of Guangzhou (and thus not covered in previous
eld surveys). Total annual pengyusai sales volume
from these 10 sellers was estimated at 1.6 t of dried
gill plates. Sellers reported that only a small
percentage of their business came from Internet
sales, since the primary pengyusai purchasers are
middle-aged housewives, who are reportedly not
accustomed to making online purchases. The 2016
1
Hong Kong and Singapore estimates assumed 75% coverage of large
sellers and 50% of remaining sellers. Macau coverage was estimated
as the percentage of stores checked out of the estimated total, since
volumes from all sellers were similar.
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Internet search identied only four sellers on Taobao,
all advertising China as the product source.
In 2011 pengyusai sellers in all markets consistently
reported difculty in sourcing gill plates, especially
manta ray gills, with large manta gills especially
scarce. All sellers responding in Singapore, Hong
Kong, and Macau commented that pengyusai was
not a popular product, with several adding that only
elderly clients purchased it or that it was too
expensive. In contrast, most Guangzhou sellers
(82%) reported increasing demand despite rising
prices,withpeaksalesinsummertoearlyautumn
(5 months). In 2013 only 55% of Guangzhou sellers
reported decreasing supply of gill plates, and 75%
reported continued increasing demand. In 2014, 64%
of the online sellers interviewedreporteddecreasing
supply, with difculty sourcing manta gills especially,
while 36% reported stable supply from Indonesia
and Sri Lanka. All of those responding to the
question on demand trends reported decreasing
demand, with two commenting that the pengyusai
business has no future. In 2015 the Guangzhou
sellers willing to discuss market trends reported
lower demand, especially for the more expensive
Manta and M. tarapacana gill plates, owing to
conservation awareness among consumers, the
Chinese government crackdown on corruption
affecting purchase of expensive gifts, and concerns
about an imminent government ban of the gill plate
trade. One large trader with more than 100 kg stock
of all three types of gill plates said the local
government had given pengyusai traders an
unspecied amount of time to sell off remaining
stock and that sales had become very difcult. Hong
Kong traders reported steady supply from Indonesia,
Sri Lanka, and lower quantities from the Philippines
(Table 3).
Mean gill plate prices were higher in 2013 than
2011 for all gill plates, with larger price increases
for both types of Mobula gill plates (Table 4).
Prices in 2015 were again higher relative to 2013,
with larger increases for M. tarapacana and Manta
gills. The ANOVA conrmed that Guangzhou gill
plate prices were signicantly different between
years (P<0.001) and species (P<0.001).
According to the large distributor interviewed,
Hong Kong prices for both types of Mobula gills
were slightly higher in 2015 relative to 2011 and
slightly lower for Manta gills.
Species composition
In all surveys, the gill plate market comprised three
main types: (1) Manta spp.; (2) M. tarapacana; and
(3) small gill plates from M. japanica,M. thurstoni,
and possibly other Mobula spp. As M. japanica and
M. thurstoni gill plates are very similar in size and
appearance and are mixed together in the same
containers, it was not possible to determine the
proportion of each species in stock estimates. A
small amount of whale shark gills marketed as
pengyusai was also observed in all three years. In
Table 3. Vendor-reported market trends in supply and demand
Survey
Supply trends Demand trends
Number of reports Stable Up Down Number of reports Stable Up Down
2011 Guangzhou 11 0 0 11 22 1 18 3
2011 Singapore 21 0 0 21 15 0 0 15
2011 Hong Kong 10 0 0 10 7 0 0 7
2011 Macau 60068008
2011 Total 48 0 0 48 52 1 18 33
Percentage of 2011 Total 0% 0% 100% 2% 35% 63%
Guangzhou % of total 0% 0% 100% 5% 82% 14%
2013 Guangzhou 11 6 2 3 24 3 18 3
Percentage of 2013 Total 55% 18% 27% 13% 75% 13%
2014 Taobao 83054004
Percentage of 2014 Total 38% 0% 63% 0% 0% 100%
2015 Guangzhou 11 3 8 0 7 0 0 7
Percentage of 2015 Total 27% 73% 0% 0% 0% 100%
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
2011 the proportion of stock by dried gill plate
volume from Guangzhou surveys was 36% Manta
spp. gill plates, 34% M. tarapacana gill plates, and
30% small gill plates from other Mobula spp. The
proportion of Manta gill plates dropped in 2013
(20%) and increased in 2015 (33%) (Figure 2).
Traders consistently referred to M. tarapacana gill
plates as ower gill, but a large variety of trade
names was used for gills from other species, often
referring to source location, size, and/or
coloration, such as Beihai penyusai,Vietnam soft
speckled gills,Myanmar speckled gills,South
American giant white pengyusai,orVietnamese
black gills.
Number of mobulids
Figure 3 illustrates the conguration of gill plates in
whole mobulids. Based on these reported yields, the
number of mobulids represented in the Guangzhou
markets annual gill plate sales was estimated at
48 400 in 2011 and 120 500 in 2013 (Table 5).
Owing to the smaller size and much lower dried
gill plate yield per animal for devil rays, these
species represented the bulk of the estimated
number of mobulids required to produce the dried
gill plate stocks observed in the Guangzhou
market surveys (90% in 2011, 96% in 2013, and
93% in 2015).
Source locations
Twenty-two different locations were reported as the
source of dried gill plates from all surveys, including
14 countries, plus Hong Kong and Taiwan, and six
continents or ocean regions (Table 6). The most
frequently reported source locations were China,
followed by China Seas (especially the northern
part of the South China Sea), Indonesia, Vietnam,
Sri Lanka, and India. Vendors reporting China as
source identied Yangjiang (Shapa Bay, Zhapo,
and Dongping Harbor), Zhangjiang (Naozhou
Island), and Maoming (Bohe) as the primary ports
for sourcing domestic gill plates. The countries
participating in the mobulid gill plate trade and
Table 4. Average dried gill plate prices per kg; local currency and USD
*
Market city
Apr 2011 surveys Dec 2013 survey Dec 2015 surveys
Local Curr USD Local Curr USD Local Curr USD
Guangzhou CNY CNY CNY
Manta spp. ¥1813 $277 ¥1970 $325 ¥2127 $329
M. tarapacana ¥1269 $194 ¥1553 $256 ¥1850 $286
M. japanica/other ¥923 $141 ¥1173 $193 ¥1218 $189
Hong Kong HKD HKD USD
Manta spp. 3670$ $472 3250$ $419
M. tarapacana 1790$ $230 1875$ $242
M. japanica/other 1450$ $187 1550$ $200
Macau HKD
Manta spp. 2670$ $343
M. tarapacana 1870$ $241
M. japanica/other 1200$ $154
Singapore SGD
Manta spp. 507$ $408
M. tarapacana 446$ $359
M. japanica/other 360$ $290
% Changes (local curr.) Apr 2011 to Dec. 2013 Dec 2013 to Dec. 2015 Apr 2011 to Dec. 2015
Guangzhou
Manta spp. 9% 8% 17%
M. tarapacana 22% 19% 46%
M. japanica /other 27% 4% 32%
Hong Kong
Manta spp. 11%
M. tarapacana 5%
M. japanica/other 7%
*
Local currency prices converted to USD using historical exchange rate tables from www.xe.com.
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
the roles played by each, based on vendor responses
across all surveys, are summarized in Table 7.
Reported medicinal uses
The pengyusai tonic is prepared as a soup with dried
gill plate pieces boiled together with other
ingredients, such as dried seahorses, pipesh or
scallops, pork or beef, and various medicinal
plants, with accompanying ingredients differing
according to the ailment to be treated. Seller
interviews and online research revealed that
pengyusai is recommended to treat a wide range of
ailments and for general health maintenance
(Table 8). In 2011, the most common health
claims included treatment for cough/phlegm,
fever, and chicken pox. By 2013, the list of
medicinal claims had expanded to include
lactation aid, health support especially for heavy
drinkers and smokers, lung, liver, and eyesight
support, and reducing inammation, irritability,
and hyperactivity (particularly for babies). In 2015
the ve vendors responding to this question during
Guangzhou surveys claimed it was for clearing the
lungs and promoting respiratory health, while
Taobao web-based sellers and Hong Kong sellers
continued to promote the same range of uses as in
previous surveys.
Of the four TCM interviews conducted in 2011,
two doctors (Macau, Hong Kong) were trained as
TCM doctors, but had stopped practising
medicine to open dried seafood stores. Both touted
the effectiveness of pengyusai for several health
issues, including cough/sore throat and chicken
pox/measles, and one (Hong Kong) explained that
it is effective for all thyroid and lymph node
related diseases including cancer. The TCM
practitioner interviewed at a Guangzhou TCM
Centre agreed when asked if pengyusai would be
an effective treatment for a child with chicken
pox, and added that it eliminates heat and is good
for the skin. However, when she realized there
were no gill plates in stock at the Centre, she said
that they were getting more difcult to source,
were not very effective, and many alternatives
were available. The other two TCM doctors
interviewed (Guangzhou and Singapore) stated
that pengyusai had no health benets and many
alternatives were available. One (Guangzhou)
further asserted that pengyusai is not a part of
standard, medically recognized, and practised
TCM, and that vendors promote the
misconception that pengyusai is prescribed as TCM.
There is no information on pengyusai in the
Compendium of Materia Medica by Dr. Li
Shi-zhen (c. 1578), which is still considered the
Figure 2. Gill plates from each species identied in this study. A = Manta spp., B = M. tarapacana,C=M. japanica,D=M. thurstoni; scale =30 cm.
Photos by Paul Hilton.
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
premier reference tool for TCM (Mainka and
Mills, 1995; Library of Congress, 2014). However,
an extensive literature review located several
recent references to pengyusai in TCM textbooks
(Lin, 1976; Anon, 1977; Peigen, 1988; Guan and
Wang, 2009). Its rst appearance in TCM
literature was in 1976 in Guangxi Medicinal
Animals, by Lin, Yu He (Shen et al., 2001), in
which pengyusai was described as the dried gills
from Mobula japonica(sic) (Lin, 1976). Manta
birostris rst appeared in China Pharmaceuticals
of Marine Biological Origin (Anon, 1977), with
Mobula japonicanoted as a sister species, and
medicinal benets described as detoxication,
clearing heat, and promoting eruption, for
treatment of measles and skin issues (ulcer and
boils). The most recent TCM reference found was
Chinese Marine Materia Medica (Guan and
Wang, 2009), which describes pengyusai as the gill
from ve types of Mantaspecies, Manta
birostris,Mobula diabolus
2
,Mobula japonica,
Aetobatus agellum
3
, and Aetobatus narinari, with
medicinal uses including detoxication, exposing
exanthema (viral disease accompanied by a skin
rash), measles, pertussis (whooping cough),
dysentery, funculus (boil), and furunculosis
(recurring boils). This reference also cites large
population declines for manta and devil ray
species due to overshing and endangered status
according to the IUCN and Chinas species red list.
DISCUSSION
Market surveys in 2011 clearly identied
Guangzhou as the centre of gill plate consumption
and trade, while estimates from the December
2013 Guangzhou survey demonstrated a worrying
trend of increased market volume, prices, and
demand. The volume of gill plates increased most
dramatically for the small Mobula spp. gill plates,
which tripled over the period. Results from 2015
surveys suggest that Guangzhou government
efforts to phase out the gill plate trade in
cooperation with an NGO demand reduction
campaign are showing signs of success in reducing
gill plate demand, but may also indicate a shift to
Hong Kong as the new centre of the trade,
possibly due in part to lax enforcement of import
control in this free trade port (Cheung and
Dudgeon, 2006).
Species found in gill plate markets, primarily
Mobula japanica,M. thurstoni,M. tarapacana,
and Manta spp., correspond to those reported
most frequently in sheries supplying the gill plate
trade (White et al., 2006b; Fernando and Stevens,
Figure 3. Gill plates per whole animal. A . Manta spp. gill plate
structure shown in live feeding manta, B . M. japanica gill plates front
view, C . M. tarapacana cut open to expose gill plates. Photos by
Mary OMalley (A), Gisele Kaufman (B) and Shawn Heinrichs (C).
2
Mobula diabolus is not a recognized species. The sketch in the book
appears to refer to Mobula tarapacana (Stevens, 2011; G. Stevens,
pers. comm.).
3
Eagle ray species
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
2011; Acebes, 2013). Recently reported evidence of
the export of gill plates from Mobula mobular,
IUCN Red List classied as Endangered
(Notarbartolo di Sciara et al., 2006), from Gaza,
Palestine (Abudaya et al., 2014) suggests that
more devil ray species may be affected by the gill
plate trade than those identied in this study. The
large number of devil rays represented in market
estimates is concerning as limited biological
information is available for these species and the
risk of unsustainable harvesting relatively high
(Couturier et al., 2012). Also concerning is the
strong preference for large manta ray gill plates
in the expanding Hong Kong market, which
could drive increased shing effort for these
species.
Table 5. Conversion of dried gills to estimated number of mobulids*
Estimated number of mobulids represented in Guangzhou annual sales 2011 and 2013
Species
Dried
gills
(kg)/
animal
Apr 2011 survey Dec 2013 survey
Change Apr. 2011 to
Dec. 2013
Dried gill plate
volume (kg)
Number of
mobulids
% per
species
Dried gill plate
volume (kg)
Number of
mobulids
% per
species
Number of
Mobulids %
Manta spp. 5 21 876 4375 9% 23 811 4762 4% +387 +9%
M. tarapacana 2.5 20 324 8130 17% 42 165 16 866 13% +8736 +107%
M. japanica /
other
0.5 17 952 35 904 74% 54 493 108 986 83% +73 082 +204%
Totals 60 152 48 409 100% 120 469 130 614 100% +82 206 +170%
*
Calculated by dividing the total estimated volume (kg) of gill plates per species by average dried gill weight (kg) per animal.
Table 6. Reported gill plate sources from vendor interviews
Reported source Total %
2015 2014 2013 2011
%%%%
Vendors reporting sources 181 33 50 30 68
China 73 40.3% 10 30% 40 80% 11 37% 12 18%
China Seas 26 14.4% 0 0% 1 2% 13 43% 12 18%
Indonesia 25 13.8% 5 15% 1 2% 4 13% 15 22%
Vietnam 13 7.2% 2 6% 1 2% 5 17% 5 7%
Sri Lanka 10 5.5% 4 12% 3 6% 1 3% 2 3%
India 9 5.0% 1 3% 0 0% 1 3% 7 10%
South America
1
8 4.4% 0 0% 1 2% 4 13% 3 4%
Malaysia 8 4.4% 3 9% 3 6% 1 3% 1 1%
South Africa 6 3.3% 2 6% 0 0% 1 3% 3 4%
Hong Kong 6 3.3% 0 0% 1 2% 1 3% 4 6%
Australia 5 2.8% 1 3% 0 0% 1 3% 3 4%
Brazil 4 2.2% 3 9% 0 0% 1 3% 0 0%
Europe 4 2.2% 0 0% 1 2% 1 3% 2 3%
Philippines 4 2.2% 3 9% 0 0% 0 0% 1 1%
Africa 3 1.7% 0 0% 0 0% 0 0% 3 4%
Taiwan 3 1.7% 0 0% 1 2% 0 0% 2 3%
Thailand 3 1.7% 1 3% 0 0% 0 0% 2 3%
Japan 2 1.1% 0 0% 0 0% 2 7% 0 0%
Middle East 2 1.1% 0 0% 0 0% 1 3% 1 1%
Myanmar 1 0.6% 0 0% 0 0% 0 0% 1 1%
Pacic Ocean 1 0.6% 0 0% 0 0% 0 0% 1 1%
Mauritius 1 0.6% 1 3% 0 0% 0 0% 0 0%
1
One seller specied Brazil.
2
Six specied South Africa.
Sources reported by sellers in Macau were Hong Kong, Taiwan and China.
Sources reported by sellers in Hong Kong were Indonesia, Sri Lanka, India, Malaysia, Australia, Thailand and Philippines.
Sources reported by sellers in Singapore were Indonesia, India, Africa, Australia and Middle East.
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Source countries for gill plates reported from this
study were comparable with mobulid shery
locations listed in the Couturier et al. (2012) and
Croll et al. (2015) mobulid conservation reviews.
However, several locations were highlighted
through the interview process that had not been
previously identied as having sheries supplying
the gill plate trade, including Vietnam, Mauritius,
Myanmar, Thailand, Japan, Australia, South
Africa, Europe, Middle East, and South America
(including Brazil specically). Gill plate exports
from these locations, however, have yet to be
veried and some may refer to illegal catches
within the waters of these countries. For example,
Indonesian shers from Tanjung Luar, Lombok
have admitted to illegally targeting mobulids in
northern Australian waters (Lewis et al., 2015), a
Hong Kong trader reported in 2015 to be
receiving manta ray gills that were illegally
transhipped from Indonesia (P. Hilton, pers.
comm.), and illegal catch of manta rays and
export of manta gill plates have been documented
in the Philippines (Rayos et al., 2012; Acebes,
2013; Asis et al., 2014). In addition Indonesia,
Australia, Brazil, and the Philippines were still
reported as sources in 2015 despite laws
prohibiting take and trade of some or all mobulid
species in these countries.
The very high proportion of reports of China as a
source of gill plate supply is questionable. The
manager of the mobulid processing plant in Puqi
stated the mobulids processed in his facility were
landed in Chinese ports, but were caught in
international waters. In addition, seller reports of
gill plates from regions where the gill plate trade
has not been observed, but in which Chinese
distant water shing eets have been reported
(Pauly et al., 2014; D. Fernando, pers. comm.),
could indicate unreported take of mobulids by
Chinese vessels in other regions. However,
documentation of the year-round presence of
whale sharks primarily off Chinas southern
provinces in the South China Sea, with an
estimated 1000 landed per year (Li et al., 2012b),
suggests a substantial local mobulid shery could
also exist. As large lter-feeding elasmobranchs
living mainly in tropical and subtropical waters,
manta and devil rays often share habitat and
aggregation areas with whale sharks (Sleeman
et al., 2007; Anderson et al., 2011; de la Parra
et al., 2011; Rohner et al., 2013; Berumen et al.,
2014) and have been targeted by the same sheries
(Alava et al., 2002; Barnes, 2005; White and
Cavanaugh, 2007). In addition, the South China
Sea has been identied as home range to seven of
the worlds 11 mobulid species (Last and
Compagno, 2002; Marshall et al., 2009).
Traditional Chinese medicine (TCM) is believed
to have originated over 5000 years ago (Mainka
and Mills, 1995; Liddick, 2011) and is one of the
most popular forms of alternative and
complementary medicines in East Asia (Leung
et al., 2003). Gill plates as a remedy rst appeared
in Chinese medicine literature in 1976 (Lin, 1976)
and the earliest reports of sheries supplying gill
plates to China came from the Philippines in the
1960s, when a buyer from Mindanao introduced
the trade (Acebes, 2013). The expansion of the gill
plate trade in the late 1990s (Dewar, 2002; Acebes,
2013) may be explained, at least in part, by the
broader trend of increased use of wildlife for
Table 7. Participants in the mobulid gill plate trade and roles played by
each according to vendor interviews
Producer
1
Importer/consumer
2
Exporter
China China China
Vietnam Hong Kong Hong Kong
Indonesia Macau Vietnam
S America Singapore Indonesia
Sri Lanka S America
Africa Sri Lanka
Malaysia Africa
Europe Malaysia
Myanmar Europe
Australia Myanmar
Japan Australia
India Japan
Taiwan India
Middle East Taiwan
Thailand Middle East
Philippines Thailand
Mauritius Philippines
Mauritius
Producer = reported as a gill plate source
Importer/consumer = reported sourcing gill plates from other regions
and selling locally
Exporter = reported by other markets as source of gill plates
1
Hong Kong was reported as a source location by some vendors in
China and Macau, but does not catch mobulids, and therefore is not
listed as a Producer. Hong Kong distributors reported that Hong
Kong imports gill plates and re-exports 7080% to China.
2
Malaysia and Canada were also identied as consumers from other
sources (Dulvy et al., 2014; Manta Trust, 2014).
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
medicinal purposes, which has escalated alarmingly
in the past decade(WWF /Dalberg, 2012).
Increasing wealth in China and the prestige
associated with being able to procure rare and
expensive remedies and foods have contributed to
this trend (Clarke et al., 2007; Fabinyi, 2011;
Graham-Rowe, 2012; Zhang and Yin, 2014).
Other factors driving demand include concerns
about toxicity and dangerous side effects from
pharmaceutical drugs (Pang, 2012) and the
common beliefs in powerful medicinal properties
associated with certain foods (Yiming and
Dianmo, 1998; Qifeng et al., 2012) and in wild-
sourced ingredients being more potent and free of
impurities than cultivated ones (Fabinyi, 2011).
Internet advertisements for gill plates frequently
focus on the purity of pengyusai, claiming it has
been harvested from pristine ocean areas, and
promoting its efcacy in improving respiratory
health. Thus Chinas air pollution crisis and
associated respiratory illnesses (Lelieveld et al.,
2015) may well be another driver of pengyusai
demand. Ironically, consumption of unregulated
animal products from unknown sources carries a
number of potential health risks from heavy metal
accumulation, toxic chemicals used in processing,
and zoonotic transmission of infectious diseases
(Still, 2003; Clarke et al., 2007; Alves et al., 2013).
Mobulid gill plates and tissues tested have been
found to contain potentially unsafe levels of heavy
metals, including arsenic, cadmium, and mercury
(Essumuang, 2009; Whitcraft et al., 2014; Oi et al.,
2015), with some gill plate samples tested
exceeding the Pharmacopoeia of China
recommended limit for arsenic by as much as 20
times (Li et al., 2012a; Whitcraft et al., 2014).
In general, prescription of remedies from
endangered animals is no longer common
(GrahamRowe, 2012), and in fact, top TCM
doctors and companies have publicly renounced
the use of products containing endangered species
(TRAFFIC, 2014). In this study apothecaries and
Table 8. Vendor-recommended uses of gill plates
Recommended use
2015 surveys 20132014 surveys 2011 surveys
Number of
vendors
Percentage of
vendors reporting
Number of
vendors
Percentage of
vendors reporting
Number of
vendors
Percentage of
vendors reporting
13 71 31
General health
*
0 0% 41 58% 11 35%
Removes toxins 1 8% 41 58% 2 6%
Chicken Pox/Small Pox/Measles 2 15% 35 49% 4 13%
Lactation aid 5 38% 33 46% 0 0%
Cough /Sore Throat /Phlegm/Tonsil
inammation (Children)
0 0% 29 41% 6 19%
Reduce internal heat 0 0% 27 38% 7 23%
Lung support 0 0% 17 24% 0 0%
Liver support 1 8% 14 20% 0 0%
Eyesight support 5 38% 13 18% 0 0%
Skin Complaints/Acne/Boils 0 0% 13 18% 5 16%
Cancer 0 0% 9 13% 1 3%
Fever 1 8% 9 13% 6 19%
Reduce inammation 6 46% 8 11% 0 0%
Aids digestion /good for stomach 1 8% 8 11% 1 3%
Overuse of alcohol-tobacco-stay up
all night
5 38% 7 10% 0 0%
Aids blood circulation 1 8% 7 10% 1 3%
Kidney support 4 31% 4 6% 5 16%
Irritability 3 23% 3 4% 0 0%
Not TCM 1 8% 3 4% 1 3%
Mumps 0 0% 1 1% 2 6%
Fertility aid 1 8% 1 1% 1 3%
Hyperactivity (babies) 1 8% 11% 0 0%
Thyroid gland support 3 23% 0 0% 1 3%
*
General Healthalso includes: Nourish Yin, Adjust Qi, Enhance physical tness, Avoid hospital/medical injections, Boosts immunity
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
TCM doctors interviewed conrmed that
prescriptions for pengyusai are rare. However, 92%
of consumers surveyed in Guangzhou in 2014
reported learning of pengyusai through word of
mouth from friends or relatives (Whitcraft et al.,
2014), and it is readily available over the counter.
In addition, vendors drive demand for animal-
derived TCM remedies with claims of medicinal
benets which are often more expansive than those
recorded in TCM texts (Graham-Rowe, 2012).
For example, rhino horn, which has been used in
Chinese medicine for thousands of years, was
originally described as a heat-clearing and
detoxifying remedy, similar to mobulid gill plates
(Nowell, 2012). However, it is now marketed by
some as a cure for cancer and to ease hangover
symptoms in Vietnam and China (Nowell, 2012).
Similarly pengyusai is marketed for a wide range
of uses that are not documented in TCM
literature. The greater percentage of sellers
promoting regular pengyusai use for general health
maintenance and the expanded list of reported
health benets in 2013 relative to 2011, suggests
trader marketing aimed at broadening the
consumer base over this period of rapid market
growth. In particular, none of the sellers or TCM
practitioners interviewed in 2011 reported
lactation aid as a benet, nor does this application
appear in any of the TCM references reviewed.
Yet this use, which clearly targets a new and
younger consumer group, was reported by 47% of
sellers in the 2013 Guangzhou survey and 2014
survey of Chinese web-based sellers.
The ndings of this study together with reported
declines in mobulid landings of 75 to 95% in
Indonesian sheries supplying the gill plate trade
over the past 10 to 15 years, despite increased
targeted effort (Lewis et al., 2015), suggest that the
gill plate trade may already have had a serious
negative impact on regional mobulid populations.
In addition a recent vulnerability analysis indicates
these species can only withstand very low levels of
shing mortality (Dulvy et al., 2014).
Consequently, the levels of trade identied by this
study are unlikely to be sustainable and could lead
to further population declines and local extinctions.
In order to develop informed conservation
strategies for manta and devil rays, the extreme
deciency of data on mobulid sheries and trade
must be addressed as an urgent priority. The latest
available trade data from the Food and
Agriculture Organization (FAO) do not
distinguish trade in rays from other elasmobranchs
(FAO, 2015), and there are no uniform customs
codes to enable tracking of trade in mobulids
(Mundy-Taylor and Crook, 2013). The FAO has
two categories in which countries can report
capture production of manta and devil rays
(Mantas,devil rays,nei and Giant manta), but only
four countries have reported in these categories
(FAO, 2015). Indonesia is the only country to
have reported mobulid landings consistently since
2005 (FAO, 2015), but even these data may not be
reliable (Fahmi and Dharmadi, 2015). To address
these data deciencies, establishment of uniform
import/export codes for manta and devil ray gill
plates and other mobulid products, and training
and capacity building to assist countries with
reporting landings at the species level will be
required. RFMOs can play an important role in
this respect. For example, in 2015 the Inter-
American Tropical Tuna Commission (IATTC)
passed a resolution that prohibits retention or sale
of mobulid rays, requires prompt release of live
animals using safe release protocols and recording
of data on discards and live releases, and includes
provisions for technical assistance and capacity
building (IATTC, 2015).
Investigations of shery landings and exports in
countries frequently cited as gill plate sources, but
for which no data on sheries or trade have been
reported, are also needed in order to prioritize
conservation efforts. Vietnam, for example, was the
third most frequently cited source country, but the
authors were unable to locate any data on mobulid
sheries or trade in this country. Similarly in China,
cited as source country in more than half of all
interviews over the study period, the only shery
data identied were from the manager of the Puqi
shark and ray processing plant in 2011. Further
surveys in southern Chinas coastal cities outside of
Guangzhou may also be warranted, particularly
Zhanjiang, Yangjiang, Jiangmen, and Zhuhai in
Guangdong Province and Beihai in Guangxi
Zhuang Autonomous Region, as vendors
commented that the Chinese ports reported as
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
mobulid landing sites were formerly small shing
communities, but had recently transformed into
major seafood markets.
A number of vendors expressed frustration with
supply difculties and increasing prices, and most
sell a range of products and therefore are not
heavily reliant on income from gill plate sales.
Therefore efforts by gill plate source and consuming
countries to restrict the supply of gill plates through
implementation and enforcement of CITES trade
restrictions, CMS protection commitments, and
domestic sheries management measures could be
highly effective in reducing the gill plate trade. The
Indonesian government announced full protection
of manta rays in January 2014 (Anon., 2014) and
has been proactive in arresting and prosecuting
traders who illegally purchase and export manta
gills (Bell, 2014; Gannon, 2014). However, source
locations reported by sellers indicate that a
substantial proportion of the mobulid gill plate
trade may violate provisions of both CITES and
CMS treaties, and few have national laws to
manage mobulid populations. Six of the 14
reported source countries plus the European Union
are parties to CMS (Australia, India, Mauritius,
Philippines, South Africa, Sri Lanka) (CMS, 2014),
which requires parties to prohibit take of these
Appendix I listed species with very limited scope for
exceptions (CMS, 2003), though to date only
Australia and the European Union have passed
such regulations. All the reported source countries
for gill plates from Appendix II listed Manta spp.
are parties to CITES (CITES, 2014). As of the
September 2014 implementation deadline, this
binding international treaty requires exporting
countries to produce non-detriment ndings
(NDFs), which certify exports are from legal and
sustainable sheries that are not detrimental to
Manta spp. populations (Vincent et al., 2013). To
date, no country has produced an NDF with
scientic support for a sustainable level of trade for
Manta spp. (CITES, 2016). The possibly
widespread misreporting of China as the country of
origin could frustrate implementation of CITES
regulations, since domestic manta ray gill plates
would not be subject to CITES restrictions (Vincent
et al., 2013). However, landing mantas caught
outside of Chinas EEZ in Chinese ports, as
reported by the Puqi processing plant manager,
would be subject to Appendix II requirements
under the Introduction from the Sea provision
(Vincent et al., 2013). Extending CITES Appendix
II restrictions to include devil rays would provide
the legal basis for strictly regulating trade in all
mobulid gill plates and facilitate trade enforcement,
while ensuring comparable conservation measures
for devil rays, which share similar biological
vulnerabilities with manta rays and face similar
threats.
Of the reported source countries, Australia
(2015) and Brazil (2013) recently prohibited take
and trade of all mobulids, and Indonesia and
the Philippines prohibit capture and trade of one
or both Manta species, but have no management
measures for Mobula spp. (Lawson et al., 2016).
Though China does not have management
measures specically applying to mobulids,
Chinas Protection of Wildlife Law species that
hunting of all CITES Appendix II listed species
is illegal without a special permit from the
Chinese government (Wenjun et al., 1996; Li
et al., 2012b; China.org.cn, 2014). However,
there are no measures in place to monitor or
manage mobuild sheriesortradeinanyofthe
other reported source countries, including the
four most frequently reported after China and
Indonesia (i.e. Vietnam, Sri Lanka, India, and
Malaysia) (Lawson et al., 2016). Programmes to
assist shing communities with sustainable
management of marine resources will be critical
to the implementation of effective conservation
measures in these countries. In Indonesia a
collaborative NGO programme is underway in
Lamakera (Solor), the countrys largest directed
mobulid shery, to help the community
transition to more sustainable sources of
income, including sustainable sheries and
practices (i.e. hand-line yellown tuna), marine
megafauna ecotourism, production of nely
woven cloth, and part-time work as marine
megafauna scientic research staff (Lewis et al.,
2015). These programmes show a great deal of
promise, and could be mirrored in other
countries supplying the market for manta and
devil ray gill plates as well as other threatened
wildlife species.
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Finally, campaigns to address demand in China,
as well as Hong Kong and Macau, are a critical
component of a mobulid conservation strategy
(Lawson et al., 2016). The growing number of
consumers who can now afford pengyusai and
other expensive remedies from threatened species
are largely unaware of the conservation and legal
implications of buying these products (Zhang
et al., 2008; Whitcraft et al., 2014). However, a
large percentage of consumers surveyed expressed
a willingness to stop consuming pengyusai for
protection of threatened wildlife (91%) or due to
the presence of heavy metals or other toxins (97%)
(Whitcraft et al., 2014), indicating that targeted
communication campaigns currently underway in
Guangzhou since May 2014 (IUCN SOS
Marine, 2014), could be effective in reducing
pengyusai demand and have likely contributed to
the market decline observed since the 2011 and
2013 surveys.
Continued measures contributing to a
comprehensive strategy integrating international
and local measures to address both the demand
for and supply of manta and devil ray gill plates
should be pursued with urgency to prevent the
continued unsustainable exploitation of these
biologically vulnerable species.
ACKNOWLEDGEMENTS
The authors thank Hui Tsi Huang for her valuable
assistance with research on TCM, legal protection
status, and Internet pengyusai sellers, and the 2015
Guangzhou survey; and Samantha Whitcraft
(Guangzhou 2013), Chris Li (Guangzhou 2013),
Angel Wong (Hong Kong 2011), Susan Su
(Guangzhou 2011), Catherine Xaria Tay
(Singapore 2011), Eby Mazini (Singapore 2011),
Wu Hung (Taiwan 2011), and Yu Min (Taiwan
2011) for all their help in collecting interview data
and preparing eld reports. We also thank Guy
Stevens and Daniel Fernando for their support in
conrming species identication of dried gill plates
and per animal dried gill plate yields, Dr. Zu Ling,
Zhu (Singapore 2011) for reviewing TCM
references for information on pengyusai, and Alex
Hofford for assistance with analysis of gill plate
samples. We are also grateful to Nick Dulvy,
Daniel Fernando, the anonymous reviewer, and
the editor for taking the time to review and
provide valuable comments to improve this
manuscript. Support for this work includes funding
and resources provided by Save Our Species
programme of the International Union for the
Conservation of Nature, Global Environment
Facility and the World Bank (grant 2013A-058),
Moreton Bay Research Station, The University of
Queensland, Hrothgar Investments, and Silvercrest
Foundation.
REFERENCES
Abudaya M, Fernando D, Notarbartolo di Sciara G. 2014.
Assessment of the Gaza Fishery of the Giant Devil Ray
(Mobula mobula), Gaza Mobula Project: Gaza, Palestine.
Acebes JM. 2013. Hunting big sh: a marine environmental
history of a contested shery in the Bohol Sea. PhD thesis,
Murdoch University.
Alava MNR, Dolumbalo 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, July 1997, Fowler SL, Reed TM, Dipper FA
(eds). IUCN Species Survival Commission No. 25;
132148.
Alves RNN, Rosa IL, Albuquerque UP, Cunningham AB.
2013. Medicine from the Wild: An Overview of the Use and
Trade of Animal Products in Traditional Medicines. In
Animals in Traditional Folk Medicine: Implications for
Conservation, Alves RNN, Rosa IL (eds). Springer: Berlin/
Heidelberg; 2542.
Anderson RC, Adam MS, Kitchen-Wheeler AM, Stevens G.
2010. Extent and economic value of manta ray watching in
Maldives. Tourism in Marine Environments 7:1527.
Anderson RC, Adam MS, Goes JI. 2011. From monsoons to
mantas: seasonal distribution of Manta alfredi in the
Maldives. Fisheries Oceanography 20: 104113.
Anon. 1977. China Pharmaceuticals of Marine Biological
Origin, Shanghai, China: Shanghai Renmin Chubanshe.
Anon. 2014. Mantas named as protected species. Jakarta Post.
http://www.thejakartapost.com/news/2014/01/28/mantas-
named-protected-species.html [28 January 2014].
Asis AM, Lacsamana JK, Santos MD. 2014. Illegal trade of
regulated and protected aquatic species in the Philippines
detected by DNA barcoding. Mitochondrial DNA 27:
659666.
Barnes RH. 2005. Indigenous use and management of whales
and other marine resources in East Flores and Lembata,
Indonesia. Senri Ethnological Studies 67:7785.
Bell L. 2014. Black market manta ray bust in Indonesia.
Mongabay.com. http://news.mongabay.com/2014/1114-
lbell-manta-ray-bust.html [14 November 2014].
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Berumen ML, Braun CD, Cochran JEM, Skomal GB,
Thorrold SR. 2014. Movement patterns of juvenile whale
sharks tagged at an aggregation site in the Red Sea. PloS
One 97: e103536. DOI:10.1371/journal.pone.0103536.
Bizarro JJ, Clark TB, Smith WD. 2006. Mobula munkiana.
The IUCN Red List of Threatened Species. Version 2014.3.
<www.iucnredlist.org>. [20 December 2014].
Camhi M, Valenti S, Fordham S, Fowler S, Gibson C. 2009.
The conservation status of pelagic sharks and rays: Report of
the IUCN Shark Specialist Group Pelagic Shark Red List
Workshop, IUCN Species Survival Commission Shark
Specialist Group: Newbury.
Cheung J. 1995. Implementation and Enforcement of
CITES: an assessment of tiger and rhinoceros
conservation policy in Asia. Pacic Rim Law and Policy
Journal 5:125159.
Cheung SM, Dudgeon D. 2006. Quantifying the Asian turtle
crisis: market surveys in southern China, 2000-2003.
Aquatic Conservation: Marine and Freshwater Ecosystems
16: 751770.
China.org.cn, 2014. Law of the Peoples Republic of China on
the Protection of Wildlife (adopted on November 8, 1988).
http://www.china.org.cn/english/environment/34349.htm
[20 December 2014].
Chow AT, Cheung S, Yip PK. 2014. Wildlife markets in South
China. HumanWildlife Interactions 8: 108112.
Clark TB, Smith WD, Bizzarro JJ. 2006a. Mobula thurstoni.
The IUCN Red List of Threatened Species. Version 2014.3.
<www.iucnredlist.org>. [20 December 2014].
Clark TB, Smith WD, Bizzarro JJ 2006b. Mobula tarapacana.
The IUCN Red List of Threatened Species. Version 2014.3.
<www.iucnredlist.org>. [20 December 2014].
Clarke S, Milner-Gulland EJ, Bjorndal T. 2007. Social,
economic, and regulatory drivers of the shark n trade.
Marine Resource Economics 22: 305327.
CMS (Convention on the Conservation of Migratory
Species of Wild Animals). 2003. http://www.cms.int/
sites/default/les/instrument/cms_convtxt_english.pdf [20
December 2014].
CMS (Convention on the Conservation of Migratory Species of
Wild Animals). 2014. http://www.cms.int/en/parties-range-
states [20 December 2014].
CITES (Convention on International Trade in Endangered Species
of Wild Fauna and Flora). 2014. http://www.cites.org/eng/
disc/parties/chronolo.php [20 December 2014].
CITES (Convention on International Trade in Endangered
Species of Wild Fauna and Flora). 2016. https://cites.org/
eng/prog/shark/Information_resources_from_Parties_and_
other_stakeholders#NDFs%20and%20NDF%20guidance
[14 February 2016].
Cortes E, Papastamatiou YP, Carlson JK, Ferry-Graham L,
Wetherbee BM. 2008. An overview of the feeding ecology
and physiology of elasmobranch shes. In Feeding and
Digestive Functions of Fishes, Cyrino JEP, Bureau D,
Kapoor BG (eds). Science Publishers: Boca Raton, FL; pp.
393443.
Couturier LIE, Marshall AD, Jaine FRA, Kashiwagi T, Pierce
SJ, Townsend KA, Weeks SJ, Bennett MB, Richardson AJ.
2012. Biology, ecology and conservation of the Mobulidae.
Journal of Fish Biology 80: 10751119.
Croll DA, DeWar H, Dulvy NK, Fernando D, Francis MP,
Galván-Magaña F, et al. 2015. Vulnerabilities and sheries
impacts: the uncertain future of manta and devil rays.
Aquatic Conservation: Marine and Freshwater Ecosystems.
DOI:10.1002/aqc.2591.
De la Parra Venegas ,R, Heuter R, Cano JG, Tyminski J,
Remolina JG, Maslanka M, Ormos A, Weigt L, Carlson B,
Dove A. 2011. An unprecedented aggregation of whale
sharks, Rhincodon typus, in Mexican coastal waters of the
Caribbean Sea. PLoS ONE 6(4): e18994. DOI:10.1371/
journal.pone.0018994.
Dent F, Clarke S. 2015. State of the global market for shark
products. FAO Fisheries and Aquaculture Technical Paper
No. 590. Rome, FAO. Available online: http://www.fao.
org/3/a-i4795e.pdf.
Dewar H. 2002. Preliminary report: Manta Harvest in
Lamakera. Peger Institue of Environmental Research,
Oceanside: CA.
Dulvy NK, Pardo SA, Simpfendorfer CA, Carlson JK. 2014.
Diagnosing the dangerous demography of manta rays using
life history theory. PeerJ 2: e400.DOI:10.7717/peerj.400.
Essumuang 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: An
International Journal 15: 985998.
Fabinyi M. 2011. Historical, cultural and social perspectives on
luxury seafood consumption in China. Environmental
Conservation 39:8392.
Fahmi D. 2015. Pelagic shark sheries of Indonesias Eastern
Indian Ocean 909 Fisheries Management Region. African
Journal of Marine Science 37: 259265.
FAO. 2015. Fishery Commodities and Trade and Global
Capture Production Datasets. FishStat.
Fernando D, Stevens G. 2011. A Study of Sri Lankas Manta
and Mobula Ray Fishery, Dorchester, UK: Manta Trust.
Gannon M. 2014. Manta Ray Trafckers Busted in Indonesia.
LiveSciencehttp://www.livescience.com/48107-manta-ray-
trafckers-busted.html [2 October 2014].
Germanov ES, Marshall AD. 2014. Running the gauntlet:
regional movement patterns of Manta alfredi through a
complex of parks and sheries. PLoSONE 9: e110071 .
DOI:10.1371/journal.pone.0110071.
Graham-Rowe D. 2012. Endangered and in demand. Nature
480: S101S103.
Guan H, Wang S. 2009. Chinese Marine Materia Medica. In
Shanghai Scientic and Technical Publishers, China Ocean
Press, and Chemical Industry Press: Shanghai, China: Beijing.
Heinrichs S, OMalley MP, Medd HB, Hilton P. 2011. Manta
Ray of Hope 2011 Report: The Global Threat to Manta and
Mobula Rays, WildAid: San Francisco, CA.
IATTC. 2015. Resolution C-15-04 on the conservation of
mobulid rays caught in association with sheries in the
IATTC. Convention Area. Inter-American Tropical
Tuna Commission 89th Meeting, Guayaquil, Ecuador.
22 June3 July 2015. Available online: https://www.
iattc.org/PDFFiles2/Resolutions/C-15-04-Conservation-
of-Mobulid-Rays.pdf
IBM Corp. 2010. SPSS Statistics for Windows version 19, IBM
Corp: Armonk, NY.
IUCN SOS Marine. 2014. http://www.iucn.org/?
uNewsID=16087 [9 July 2014]
Last PR, Compagno LJV. 2002. Review of the biodiversity
of rays in the South China Sea and adjacent areas. In
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
Elasmobranch Biodiversity, Conservation and
Management: Proceedings of the International Seminar
and Workshop, Sabah, Malaysia, July 1997,FowlerSL,
Reed TM, Dipper FA (eds). IUCN Species Survival
Commission No. 25; 6469.
Lawson JM, Walls RHL, Fordham SV, OMalley MP, Heupel
MR, Stevens G, Fernando D, Budziak A, Simpfendorfer CA,
Davidson LNK, et al. 2016. Sympathy for the devil: a
conservation strategy for devil and manta rays. PeerJ
Preprints 4: e1731v1. DOI:10.7287/peerj.preprints.1731v1.
Lelieveld J, Evans JS, Fnais M, Giannadaki D, Pozzer A. 2015.
The contribution of outdoor air pollution sources to
premature mortality on a global scale. Nature 525: 367371.
Leung PC, Xue CC, Cheng YC (Eds). 2003. A Comprehensive
Guide to Chinese Medicine, World Scientic Publishing:
River Edge, NJ.
Lewis SA, Setiasih N, Fahmi D, OMalley MP, Campbell SJ,
Yusuf M, Sianipar A. 2015. Assessing Indonesian manta
and devil ray populations through historical landings and
shing community interviews. PeerJ Pre-Prints 3: e1642.
DOI:10.7287/peerj.preprints.1334v1.
Li L, Zhao Y, Bennett EL. 2007. Report of a survey on saiga
horn in markets in China. In Convention on the Trade in
Endangered Species of Wild Fauna and Flora, Fourteenth
meeting of the Conference of the Parties, The Hague,
Netherlands, 315 June 2007, Society: Wildlife Conservation.
Li S. c.1578. Ben Cao Gang Mu (Compendium of Materia
Medica). http://dl.wdl.org/3044/service/3044.pdf
Li W, Wang Y, Norman B. 2012a. A preliminary survey of
whale shark Rhincodon typus catch and trade in China: an
emerging crisis. Journal of Fish Biology 80: 16081618.
Li SM, Fang Y, Ning HM, Wu YX. 2012b. Heavy metals in
Chinese Therapeutic Foods and Herbs. Journal of the
Chemical Society of Pakistan 34: 10911095.
Library of Congress World Digital Library. 2014.
Compendium of Materia Medica. http://www.wdl.org/en/
item/4678
Liddick DR. 2011. Crimes Against Nature: Illegal Industries
and the Global Environment, Praeger: Santa Barbara, CA.
Lin YH. 1976. Guangxi Medicinal Animals. Guangxi Renmin
Chubanshe: Nanning, Guangxi Zhuang Autonomous
District, China.
Mainka SA, Mills JA. 1995. Wildlife and Traditional Chinese
Medicine Supply and Demand for Wildlife Species.
Journal of Zoo and Wildlife Medicine 26: 193200.
Manta Trust. 2014. Malaysia Mobulid Ray Project. http://
www.mantatrust.org/in-the-eld/malaysia
Marshall A, Kashiwagi T, Bennett MB, Deakos MH,
Stevens G, McGregor F, Clark T, Ishihara H, Sato K.
2011a. Manta alfredi. The IUCN Red List of Threatened
Species. Version 2014.3. <www.iucnredlist.org>.[20
December 2014].
Marshall A, Kashiwagi T, Bennett MB, Harding M, Stevens G,
Kashiwagi T. 2011b. Manta birostris. The IUCN Red List of
Threatened Species. Version 2014.3. <www.iucnredlist.org>.
[20 December 2014].
Marshall AD, Compagno LJV, Bennett MB. 2009.
Redescription of the genus Manta with resurrection of
Manta alfredi (Krefft, 1868) (Chondrichthyes;
Myliobatoidei; Mobulidae). Zootaxa 2301:128.
Milner-Gulland EJ, Bukreeva OM, Coulson T, Lushchekina
AA, Kholodova MV, Bekenov AB, Grachev IA. 2003.
Reproductive collapse in saiga antelope harems. Nature
422: 135.
Mundy-Taylor V, Crook V. 2013. Into the deep: implementing
CITES measures for commercially-valuable sharks and
manta rays. Report prepared for the European Commission,
TRAFFIC: Cambridge, UK.
Notarbartolo di Sciara G. 1987. A revisionary study of the
genus Mobula Ranesque 1810 (Chondrichthyes,
Mobulidae) with the description of a new species.
Zoological Journal of the Linnean Society 91:191.
Notarbartolo di Sciara G. 1988. Natural history of the rays of
the genus Mobula in the Gulf of California. US Fish and
Wildlife Service Fishery Bulletin 86:4566.
Notarbartolo di Sciara G., Serena F, Mancusi C. 2006. Mobula
mobular. The IUCN Red List of Threatened Species. Version
2014.3. <www.iucnredlist.org>. [20 December 2014].
Nowell K. 2012. Species trade and conservation Rhinoceroses:
Assessment of Rhino Horn as a Traditional Medicine. A
report prepared for the CITES Secretariat (CITES SC62
Doc. 47.2 Annex (Rev. 2). TRAFFIC, Cambridge, UK.
Oi MSM, Townsend KA, Bennett MB, Richardson A, Fernando
D, Gaus C, Villa AC. 2015. Levels of arsenic, cadmium, lead
and mercury in the branchial plate and muscle tissue of
Mobulid rays, and their implications for public health and
conservation. Marine Pollution Bulletin 94:251259.
Paig-Tran EWM, Kleinteich T, Summers AP. 2013. The Filter
Pads and Filtration Mechanisms of the Devil Rays: Variation
at Macro and Microscopic Scales. Journal of Morphology
274: 10261043.
Pang E. 2012. Costly Remedies Endangered Species and
Traditional Chinese Medicine. eChinacities.com. http://www.
echinacities.comwww.echinacities.com/news/Costly-Remedies-
Endangered-Species-and-Traditional-Chinese-Me-dicine [28
May 2012].
Pauly D, Belhabib D, Blomeyer R, Cheung WWWL, Cisneros-
Montemayor AM, Copeland D, Harper S, Lam VWY, Mai
Y, le Manach F, et al. 2014. Chinas distant-water sheries
in the 21st Century. Fish and Fisheries 15: 474488.
Peigen X. 1988. Zhongguo ben cao tu lu, 1st edn.Beijing, China:
Hong Kong Commercial Press.
Qifeng Z, Gan J, Xun L. 2012. Eating habits in south China
driving endangered animals to extinction. ChinaDialogue.
https://www.chinadialogue.net/article/show/single/en/5506-
Eating-habits-in-south-China-driving-endangered-animals-
to-extinction- [18 December 2012].
Rajapackiam S, Mohan S, Rudramurthy N. 2007. Utilization
of gill rakers of lesser devil ray Mobula diabolus a new
sh byproduct. Marine Fisheries Information Service
Technical and Extension Series 191:2223.
Rayos JCC, Santos MD, Barut NC. 2012. Devil Ray resources
in Bohol sea, Philippines. Fish for the People 10:2023.
Rohner CA, Couturier LIE, Richardson AJ, Pierce SJ,
Prebble CEM, Gibbons MJ, Nichols PD. 2013. Diet of
whale sharks Rhincodon typus inferred from stomach
content and signature fatty acid analyses. Marine
Ecology Progress Series 493:219235.
Shen X, Jia F, Zhou J. 2001. Anti-tumor effect of preparation
extracted from sea sh Manta birostris.Chinese Journal of
Marine Drugs 84:3529.
Sleeman JC, Meekan MG, Wilson SG, Jenner CKS, Jenner
MN, Boggs GS, Steinberg CC, Bradshaw CJA. 2007.
Biophysical correlates of relative abundance of marine
THE MANTA AND DEVIL RAY GILL PLATE TRADE
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
megafauna at Ningaloo Reef, Western Australia. Marine and
Freshwater Research 58: 608623.
Stevens G. 2011. Field Guide to the Identication of Mobulid Rays
(Mobulidae): Indo-West Pacic, Manta Trust: Dorchester, UK.
Stevens G. 2013. Field Identication Guide of the Prebranchial
Appendages (Gill Plates) of Mobulid Rays for Law
Enforcement and Trade Monitoring Applications, Manta
Trust: Dorchester, UK.
Still J. 2003. Use of animal products in traditional Chinese
medicine: environmental impact and health hazards.
Complementary Therapies in Medicine 11: 118122.
Thorrold SR, Afonso P, Fontes J, Braun CD, Santos RS,
Skomal GB, Berumen ML. 2014. Extreme diving behavior
in devil rays links surface water and the deep ocean. Nature
Communications 5(474). DOI:10.1038/ncomms5274.
TRAFFIC. 2014. Top traditional medicine companies and
doctors renounce use of endangered wildlife products.
http://www.trafc.org/home/2014/6/5/top-traditional-
medicine-companies-and-doctors-renounce-use. html?pri-
nterFriendly=true [5 June 2014].
Valenti SV, Kyne PM. 2009. Mobula rochebrunei. The IUCN
Red List of Threatened Species. Version 2014.3. www.
iucnredlist.org. [20 December 2014].
Vincent ACJ. 1997. Trade in pegasid shes (sea moths),
primarily for traditional Chinese medicine. Oryx 31: 199208.
Vincent ACJ, Sadovy de Mitcheson YJ, Fowler SL, Lieberman S.
2013. The role of CITES in the conservation of marine shes
subject to international trade. Fish and Fisheries 15: 563592.
Ward-Paige CA, Davis B, Worm B. 2013. Global Population
Trends and Human Use Patterns of Manta and Mobula
Rays. PloS One 8(9): e74835. DOI:10.1371/journal.pone.
0074835.
Wenjun L, Fuller TK, Sung W. 1996. A survey of wildlife
trade in Guangxi and Guangdong, China. TRAFFIC
Bulletin 16:916.
Whitcraft S, OMalley MP, Hilton P. 2014. The Continuing
Threat to Manta and Mobula Rays: 20132014 Market
Surveys, Guangzhou, China. WildAid, San Francisco,
CA.
White WT, Cavanaugh RD. 2007. Whale shark landings in
Indonesian artisanal shark and ray sheries. Fisheries
Research 84: 128131.
White WT, Giles J, Dharmadi PIC. 2006a. Data on the bycatch
shery and reproductive biology of mobulid rays
(Myliobatiformes) in Indonesia. Fisheries Research 82:6573.
White WT, Clark TB, Smith WD, Bizzarro JJ. 2006b.
Mobula japanica. The IUCN Red List of Threatened
Species. Version 2014.3. <www.iucnredlist.org>.[20
December 2014].
WWF / Dalberg. 2012. Fighting illicit wildlife trafcking:A
consultation with governments. WWF International,
Gland, Switzerland. http://d2ouvy59p0dg6k.cloudfront.
net/downloads/wwfghtingillicitwildlifetrafcking_lr_1.pdf
[14 February 2016].
Yiming L, Dianmo L. 1998. The dynamics of trade in live
wildlife across the Guangxi border between China and
Vietnam during 19931996 and its control strategies.
Biodiversity and Conservation 7: 895914.
Zhang L, Yin F. 2014. Wildlife consumption and conservation
awareness in China: a long way to go. Biodiversity and
Conservation 23: 237181.
Zhang L, Hua N, Sun S. 2008. Wildlife trade, consumption and
conservation awareness in southwest China. Biodiversity and
Conservation 17: 1493516.
M. P. OMALLEY ET AL.
Copyright #2016 The Authors. Aquatic Conservation: Marine and Freshwater
Ecosystems published by John Wiley & Sons, Ltd.
Aquatic Conserv: Mar. Freshw. Ecosyst. (2016)
... Nursery areas are crucial for many elasmobranch species, providing benefits that increase fitness and survival, such as food availability and protection from predators (Martins et al. 2018). Even so, the juvenile life stage of all mobulid species remains poorly studied (Stewart et al. 2018 Even with considerable actions taken to contain the catches of these species, mobulids continue to be captured worldwide as targeted fishing, because their gills are sold to the Asian market, coming from several countries, including Brazil (Croll et al. 2016;O'Malley et al. 2017) and captured as bycatch in both recreational and commercial fishing gears, including harpoon, gill net, longline, trawl, purse seine, and traps (Mas et al. 2015;Croll et al. 2016). ...
Article
Although mobulids (Mobulidae) are threatened with extinction, basic information about their biology and ecology is still lacking. Therefore, we analyzed impacts of fishing, morphology, coloration, and stomach content of mobulid carcasses stranded on the coast of Ilha Comprida, southeastern Brazil, found in protected areas of sustainable use. The carcasses were of a juvenile female manta ray (believed to be Mobula cf. birostris), two adult females M. birostris (one with a partially aborted fetus), and two adult M. hypostoma (one female with an aborted fetus, and one male). The stomach content of a M. birostris consisted almost exclusively of a newly reported prey item, the sergestid Acetes americanus, highlighting the variation of prey items in the species’ diet. This is the first record of a pregnant M. birostris in the South Atlantic Ocean and the first account of A. americanus as a mobulid prey item. The reported mobulids have been impacted by fishing activities, even within sustainable use protected areas, highlighting the importance of improving surveillance in the area and the communication between the fishing communities, scientists, and managers for designing better conservation plans for the species. Future research and conservation efforts are urgently needed to better understand the spatial and temporal distribution of mobulids, as well of its prey A. americanus, to further confirm that mobulids use this site as a feeding and nursery area and to reduce the anthropogenic impacts on these endangered populations.
... The demand for Mobula spp. branchial gill plates, used in Chinese non-traditional medicinal markets primarily located in Guangzhou, Macau, Hong Kong, and Singapore (Heinrichs et al., 2011), incentivizes fishers to target manta rays; this trade has become the most significant contributor to manta ray population declines globally O'Malley et al., 2017;Stewart et al., 2018a). ...
Article
Full-text available
Background The reef manta ray ( Mobula alfredi ) is a globally threatened species and an iconic tourist attraction for visitors to Indonesia’s Komodo National Park (NP). In 2013, manta ray fishing was banned in Komodo NP and its surroundings, preceding the nationwide manta ray protection in 2014. Over a decade ago, a previous acoustic telemetry study demonstrated that reef manta rays had high fidelity to sites within the park, while more recent photo-identification data indicated that some individuals move up to 450 km elsewhere. Characterization of manta ray demographics, behavior, and a focused assessment on site use of popular tourism locations within the park is vital to assist the Komodo NP Management Authority formulate appropriate manta ray conservation and management policies. Methods This study uses a long-term library ( MantaMatcher.org ) of photo-identification data collected by researchers and citizen scientists to investigate manta ray demographics and habitat use within the park at four sites frequented by tour operators: Cauldron, Karang Makassar, Mawan, and Manta Alley. Residency and movements of manta rays were investigated with maximum likelihood analyses and Markov movement models. Results A total of 1,085 individual manta rays were identified from photographs dating from 2013 to 2018. In general, individual manta rays displayed a higher affinity to specific sites than others. The highest re-sighting probabilities came from the remote southern site, Manta Alley. Karang Makassar and Mawan are only ~5 km apart; however, manta rays displayed distinct site affinities. Exchange of individuals between Manta Alley and the two central sites (~35.5 km apart) occurred, particularly seasonally. More manta rays were recorded traveling from the south to the central area than vice versa . Female manta rays were more mobile than males. Similar demographic groups used Karang Makassar, Mawan, and Manta Alley for foraging, cleaning, cruising, or courtship activities. Conversely, a higher proportion of immature manta rays used the northern site, Cauldron, where foraging was commonly observed. Fishing gear-related injuries were noted on 56 individuals (~5%), and predatory injuries were present on 32 individuals (~3%). Tourism within the park increased from 2014 to 2017, with 34% more dive boats per survey at Karang Makassar and Mawan. Discussion The Komodo NP contains several distinct critical habitats for manta rays that encompass all demographics and accommodate seasonal manta ray movements. While the present study has not examined population trends, it does provide foundational data for such work. Continued research into manta ray abundance, long-range movements, and identifying and protecting other critical aggregation areas within the region is integral to securing the species’ recovery. We provide management recommendations to limit undue pressure on manta rays and their critical habitats from tourism.
... Tourism is still permitted under the limitations of carrying capacity and with respect to a strict code of ethics. Despite this regulation, demand for oceanic manta ray products for the Asian medical market is increasing (O'Malley et al. 2017), while meat consumption is primarily for domestic purposes (Lewis et al. 2015). The Savu Sea, notably in East Flores, has become the world's most extensive artisanal fishing place for oceanic manta rays (Lewis et al. 2015). ...
Article
Full-text available
The Savu Sea, one of Indonesia's top conservation priorities, is home to various marine charismatic species, including the oceanic manta ray (Mobula birostris), whose conservation status is currently endangered and is protected by the Indonesian government. However, due to domestic and global demand for its fishery products, as well as shortcomings in fisheries management, this species is still poached and bycaught in the Savu Sea. Understanding their population structure is important to achieve effective conservation and fisheries management strategies that will have a positive impact on preserving their population in this area. This study aims to reveal the genetic variation of oceanic manta rays in the Savu Sea. Thirty samples from three locations in the Savu Sea were successfully preserved from East Flores (24), West Manggarai (4), and Rote Ndao (2) and then analyzed using ND5 locus from Mithocondiral DNA (mtDNA). The result indicated a close genetic relationship between three locations (East Flores, West Manggarai, and Rote Ndao) based on the phylogenetic tree and Analysis of Molecular Variance (AMOVA) result with value of 0.05158 (P-value = 0.62268) indicated as a single population. In conclusion, the findings of this study provide some insight into the possibility of manta ray populations in the Savu Sea having strong connectivity between areas, which is critical information for regulators and managers to integrate conservation and management strategies within the Savu Sea.
... These life history traits make manta rays particularly vulnerable to increased mortality rates, as populations cannot easily recover from depletion (Dulvy et al., 2014;Lawson et al., 2017). The predominant threat to manta rays worldwide is overexploitation by fisheries, which have, in part, been driven by the high demand for mobulid gill plates in Asian markets (Ward-Paige et al., 2013;Croll et al., 2016;Lawson et al., 2017;O'Malley et al., 2017). To address the growing threat of the gill plate trade, both manta species were listed on Appendix II of the Convention on International Trade in Endangered Species in 2013, and they are also listed on Appendices I and II of the Convention on the Conservation of Migratory Species (Lawson et al., 2017). ...
Article
Full-text available
Manta ray populations worldwide are vulnerable to sublethal injuries resulting from human activities, e.g., entanglement in fishing line and boat strikes, which have the potential to impact an individual’s health, fitness, and behaviour. Sublethal injuries and physical abnormalities also occur naturally from predation events, deformity, parasites, and disease. To determine the type and frequency of anthropogenic and natural originated injury events affecting Mobula alfredi and M. birostris in the Maldives, we examined data from the Manta Trust’s Maldivian Manta Ray Project (MMRP) database, which contains 73,638 photo-identification (photo-ID) sightings of the two manta ray species from 1987 to 2019. The likely origin of each injury or physical abnormality was determined based on visual assessment of the photo-ID images. Multiple injuries to an individual originating from the same event were grouped for analysis. Generalised linear mixed models (GLMM) were used to investigate the relationship between the occurrence of injury events and the explanatory variables sex and maturity status for both species, with the additional variable site function (cleaning, feeding, cruising) investigated for M. alfredi. Spatial and temporal variations in M. alfredi injury events, and their origin and type, were investigated by calculating the percentage of injury events per sighted individual at each Maldivian atoll, and per re-sighted individual in each year from 2005 to 2019. For both species, injury events were predominantly of natural origin, with predatory bites being the most frequent type. The most common anthropogenic injury type was entanglement in fishing line. Injuries to M. alfredi were significantly more likely to be observed on juveniles than adults, males than females, and at cleaning stations as opposed to feeding or cruising sites. Neither sex nor maturity status were significant explanatory variables for the occurrence of injuries to M. birostris. Highest percentages of anthropogenic injuries per sighted M. alfredi were recorded in North Malé, South Malé, Baa, Addu, and Laamu Atolls, where boat traffic, fishing, and tourism activities are concentrated. Overall, this work greatly improves understanding of the sublethal threats faced by manta rays in the Maldives; identifying focus areas where conservation management actions are required to ensure more effective protection of this threatened species group.
... Additionally, a mark-recapture analysis of sightings data from 1052 individual Raja Ampat reef manta rays from 2009 to 2019 revealed significant annual increases in estimated population size in both the Dampier Strait and South East Misool MPAs [19]. By comparison, the well-studied reef manta ray population in Mozambique, which has been targeted in subsistence fisheries [20] showed a decreasing trend in apparent survival over 15 years (2003-2018), suggesting high mortality linked to continuing pressure from targeted fisheries and insufficient conservation efforts to protect the population [4,21]. ...
Article
Despite a precipitous decline in global populations of sharks and rays over the past fifty years due to overfishing, and increasing concerns over the conservation status of manta and devil rays worldwide, manta ray populations in Raja Ampat in the Papuan Bird’s Head Seascape of Indonesia are seemingly thriving. Reef manta rays (Mobula alfredi) in particular are abundant and have higher rates of pregnancy than have been recorded elsewhere in the Indo-Pacific, and have demonstrated a significant population increase over the past decade of monitoring. Here we document two decades’ of conservation efforts in the Bird’s Head Seascape (BHS) which, when considered in their entirety, represent an organically-developed, holistic approach to manta ray conservation that has demonstrated compelling evidence of success despite ongoing challenges. We provide detailed insights on the adaptive, continuously evolving approach used for manta ray conservation in the BHS in order that this approach might inform similar efforts towards elasmobranch conservation in other areas of the developing tropics.
... Some species of chondrichthyans (sharks, rays and chimaeras), marine turtles, sea snakes, marine mammals, seabirds and teleosts are threatened with extinction due to bycatch (Wallace et al. 2013;Davidson et al. 2015;Phillips et al. 2016;Gray and Kennelly 2018;Dias et al. 2019;Lopez-Mendilaharsu et al. 2020;Nelms et al. 2021;Pacoureau et al. 2021). Depending on a fishery's management framework and markets, some of these species may be targeted, retained incidental catch (including retention of shark fins and manta and devil ray gill plates and discarding of the remaining carcass) or discarded (Elfes et al. 2013;Cao et al. 2014;O'Malley et al. 2016;Dulvy et al. 2017;Hall et al. 2017). There is extremely limited understanding of the conservation status of most teleost bycatch species due to poor data quality and few assessments. ...
Article
Full-text available
Participatory decision tools enable stakeholders to reconcile conflicting natural resources management objectives. Fisheries targeting highly productive species can have profound impacts on co-occurring bycatch species with low fecundity and other life history traits that make them vulnerable to anthropogenic sources of mortality. This study developed a decision tool for integrated bycatch management for data-limited to data-rich fisheries, improving upon current piecemeal approaches. First, through a systematic literature review, participants compile a comprehensive database of methods to mitigate the catch and fishing mortality of threatened bycatch species. These mitigation methods are then categorized into tiers of a sequential mitigation hierarchy, where interventions that avoid capture are considered before those that minimize catchability, followed by methods that minimize fishing mortality, before approaches that offset residual impacts. The methods are also assembled within an evidence hierarchy, where findings from meta-analytic modelling studies are more robust and generalizable than from individual studies. The decision tool enables stakeholders to evaluate alternative bycatch management strategies’ efficacy at meeting specific and measurable objectives for mitigating the catch and mortality of bycatch and for costs from multispecies conflicts, economic viability, practicality and safety, while accounting for the fishery-specific feasibility of compliance monitoring of alternative bycatch management measures. Ongoing adaptation of the bycatch management framework addresses findings from performance assessments, updated evidence, new mitigation methods and changes to governance systems. The proposed decision tool therefore enables stakeholders to develop bycatch management frameworks that provide precautionary protection for the most vulnerable populations with acceptable tradeoffs.
... Listed as Vulnerable to Extinction on the IUCN Red List (Marshall et al. 2018), reef manta rays have been increasingly targeted by fisheries due to the high value of their gill-plates on the Asian market , O'Malley et al. 2017. Globally, the last IUCN assessment reports a suspected population reduction of 30−49% over the past 3 generations, with further reduction predicted over future generations (Marshall et al. 2018). ...
Article
Full-text available
Our understanding of the genetic connectivity of manta ray populations and the drivers that shape genetic structure is still limited. This information is crucial to identify the spatial boundaries of discrete populations and guide decisions on units to conserve. In this study, we use genome-wide single nucleotide polymorphisms (SNPs) to assess the genetic structure and diversity of reef manta rays Mobula alfredi at a local scale within New Caledonia and regionally in the western Pacific Ocean. We provide the first evidence of fine scale genetic differentiation in M. alfredi, found between the 3 cleaning station aggregation sites in New Caledonia (n = 65) (N = 2676 SNPs, FST = 0.01, p < 0.0001). Furthermore, population structure was evident at the regional scale between individuals from New Caledonia (NC, n = 73) and East Australia (EA, n = 19) on the basis of genetic differentiation statistics (3619 SNPs, FST = 0.096, p < 0.0001) and clustering algorithms, with unidirectional gene flow detected from east (NC) to west (EA). These results reveal that reef manta rays can form genetically distinct groups within a relatively small geographic range and highlights the need to consider genetic structure when designating management units for conservation action and planning.
... In the Eastern Pacific of Costa Rica, by-catch mortalities are mainly associated to tuna purse-seine fisheries, often concentrated at the Costa Rican Dome (Croll et al. 2016;Lezema-Ochoa et al., 2019). Targeted fisheries of devil rays mainly occur in Mexico, Peru, and Ecuador, either for local and regional use and consumption of its meat or to supply the Asian medicinal market with its gill plates, where they are traded at high prices Croll et al., 2016;O'Malley et al., 2017). As a member state of relevant international treaties, such as the Convention on the Conservation of Migratory Species of Wild Animals (CMS), Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), and the Inter-American Tropical Tuna Commission (IATTC), both manta and devil rays are protected under international and national law. ...
Article
Full-text available
Introduction: Identifying critical habitats for vulnerable elasmobranch species is crucial for effective conservation measures. The Munk’s devil ray (Mobula munkiana) is endemic to the Eastern Pacific, but yet little is known about its biology, ecology, and habitat use. As filter feeders, it is assumed that this species concentrates at high-productive upwelling regions, such as the Costa Rican Dome. Like many elasmobranchs, its populations are highly depleted and require urgent information to inform better conservation measures. Objective: The study was conducted to gain information on a unique behavior observed in juvenile M. munkiana, so further information can be provided on early life stages of this vulnerable species. Methods: From June to September 2017 and in August 2018, the feeding behavior of juvenile Mobula munkiana was observed in two shallow bays located at Punta Descartes, North Pacific Costa Rica. Individuals were captured using a non-lethal method to obtain data on size, weight, and sex distribution. Plankton samples (n = 100) were taken at both bays throughout the months to infer diet composition. Results: Munk’s devil rays showed a repetitive swimming movement parallel to the beach, feeding exclusively in the shallow breaking zone of the low tide waves at depth <50cm. A total of 12 M. munkiana (11 live and one found dead) indicated a juvenile feeding aggregation ranging from 490 – 610mm in disk width and 1400 – 2300gr in weight. The sex ratio (males to females) was 3:1. Zooplankton of the order Mysidacae was found in the highest abundance in the breaking zone. Conclusions: The specific behavior and seasonal occurrence of juvenile Munk’s devil rays in this area seem to be driven by prey abundance. More research is needed to conclude the presence of reproductive adults at deeper depths and the year-round habitat use of Punta Descartes. The area is threatened by unsustainable development and requires realistic management strategies to guarantee the survival of vulnerable species and their critical habitats.
... In the Eastern Pacific of Costa Rica, by-catch mortalities are mainly associated to tuna purse-seine fisheries, often concentrated at the Costa Rican Dome (Croll et al. 2016;Lezema-Ochoa et al., 2019). Targeted fisheries of devil rays mainly occur in Mexico, Peru, and Ecuador, either for local and regional use and consumption of its meat or to supply the Asian medicinal market with its gill plates, where they are traded at high prices Croll et al., 2016;O'Malley et al., 2017). As a member state of relevant international treaties, such as the Convention on the Conservation of Migratory Species of Wild Animals (CMS), Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), and the Inter-American Tropical Tuna Commission (IATTC), both manta and devil rays are protected under international and national law. ...
Book
Full-text available
The North Pacific and the South Pacific of Nicaragua is a region of great biological, geological, economic and social wealth. There the dry forest mixes with the rain forest, the sea with the islands and nature with the people. It is a region influenced by the Papagayo upwelling, the emergence of cold marine waters during the dry season, which generates an abundance of life in the sea. As a sample of this marine wealth, in this Special Issue, more than half of the contributions are dedicated to advances in the knowledge of the marine biodiversity of the region. Contributions from the social sciences, geology and physics of the region are also included. Within these areas, the publications provide information on maritime border management, archaeology and sustainable tourism, coastal geology, projected climate changes, as well as various oceanographic aspects of the area. We hope that this Special Issue on the North Pacific of Costa Rica and the South Pacific of Nicaragua will promote more research in the region and help inform decision-making processes and educational activities. We thank the authors for their manuscripts, as well as the more than sixty reviewers who with their comments and suggestions helped to improve the quality of the manuscripts.
Article
Manta and devil rays (collectively mobulids) belong to the monogeneric Mobulidae, which currently comprises ten species, including a putative third manta ray species (Mobula cf. birostris). These large planktivorous rays are distributed throughout the tropical and subtropical oceans of the world. To date, six mobulid species are reported for the Western Atlantic Ocean and the Caribbean Sea; three of which had previously been reported in Venezuela (M. birostris, M. tarapacana and M. hypostoma). A preliminary assessment of fishery landings and citizen science data was conducted to further the scientific knowledge of mobulid species in Venezuela. Fisheries landing data was collected at Margarita Island between 2006 and 2007, and again in 2014. Data mining of internet search engines and social media platforms spanning the last two decades was also conducted. A total of 117 individuals of five mobulid species were recorded: Mobula sp. (n=27), M. birostris (n=36), M. tarapacana (n=3), M. mobular (n=26), M. thurstoni (n=14) and M. cf. birostris (n=11). The latter three species are the first confirmation of these species in Venezuela. We found no records of the previously reported M. hypostoma during this study. Although the occurrence of M. hypostoma in Venezuela remains possible due to the broad regional range of this species, its current presence in Venezuela is invalidated given the repeated misidentifications which have occurred in previous publications. Our results increase the number of reported mobulid ray species in Venezuela to five (excluding M. hypostoma). The overall data from juvenile manta rays and pregnant M. mobular and M. thurstoni recorded in this study, combined with the occurrence of all but one species of mobulid ray found in the Western Atlantic Ocean, suggest Venezuela provides important habitat for this threatened family of rays.
Article
Full-text available
International concern is growing with regard to the sustainability of manta and devil ray (collectively mobulids) fisheries as demand for mobulid products has increased in international markets over the last decade. While Indonesia has been reported to be one of the worlds’ top three catchers of mobulid rays, detailed information on these fisheries and the status of Indonesian mobulid populations are lacking. Through collection of historical and recent mobuild fisheries data from published and unpublished sources, this study aimed to identify trends in abundance of Indonesian manta and devil rays and explore socio-economic factors and incentives associated with mobulid fisheries. Comparison of catches from 2001-5 to the most recent data from 2013-14 revealed dramatic declines in mobulid landings over the study period of 64% at Cilacap, 75% at Lamakera, and 94% at Tanjung Luar. The largest declines were observed for Manta spp. and the two large devil rays, Mobula tarapacana and Mobula japanica. Anecdotal reports indicated that catches had declined substantially at three additional sites and local extirpations are strongly suspected to have occurred at three locations. A lack of data on the population ecology of Indonesia’s mobulids makes it difficult to determine whether natural fluctuations may be playing a part in the declining catch rates. However, mobulid life history traits, including low reproductive rates and late age of sexual maturation, indicate that fishing pressure is likely the primary driver in these declines. Interviews in Lamakera, a community which depends on income from its targeted mobulid fishery, suggest that programs focused on education, training and infrastructure development to enable shifts to sustainable livelihood alternatives are likely to offer the most successful path to long-term conservation and management of manta and devil rays, while simultaneously yielding economic and social benefits to fishing communities.
Preprint
Full-text available
Background. Increased interest in luxury products and Traditional Chinese Medicine, associated with economic growth in China, has been linked to depletion of both terrestrial and marine wildlife. Among the most rapidly emerging concerns with respect to these markets is the relatively new demand for gill plates, or Peng Yu Sai (?Fish Gills?), from devil and manta rays (subfamily Mobulinae). The high value of gill plates drives international trade supplied by largely unmonitored and unregulated bycatch and target fisheries around the world. Devil and manta rays are especially sensitive to overexploitation because of their exceptionally low productivity (maximum intrinsic rate of population increase). Scientific research, conservation campaigns, as well as international and national protections that restrict fishing or trade have increased in recent years. Many key protections, however, apply only to manta rays. Methods. We review the state of the development of scientific knowledge and capacity for these species, and summarise the geographic ranges, fisheries and national and international protections for these species. We use a conservation planning approach to develop the Global Devil and Manta Ray Conservation Strategy, specifying a vision, goals, objectives, and actions to advance the conservation of both devil and manta rays. Results and Discussion. Generally, there is greater scientific attention and conservation focused on Manta compared to Devil Rays. We discuss how the successes in manta ray conservation can be expanded to benefit devil rays. We also examine solutions for the two leading threats to both devil and manta rays ? bycatch and target fisheries. First, we examine how can the impact of bycatch fisheries can be reduced through international measures and best-practice handling techniques. Second, we examine the role that responsible trade and demand can play in reducing target fisheries for gill plates. Our paper suggests that given similarities in sensitivity and appearance, particularly of the dried gill plate product, conservation measures may need to be harmonised particularly for the larger species in this subfamily.
Article
The taxonomic history of the genus Manta has been questionable and convoluted, with Manta having one of the most extensive generic and species synonymies of any living genus of cartilaginous fish. Having previously been considered a monotypic genus with a single recognized species, Manta birostris (Walbaum 1792), new evidence, in the form of morphological and meristic data, confirm that two visually distinct species occur, both with wide ranging distributions through many of the world’s oceans. Manta birostris stands as the most widely distributed member of the genus, while Manta alfredi (Krefft 1868), resurrected herein, represents a smaller, more tropical species. Separation of the two species is based on morphometric measurements and external characters including colouration, dentition, denticle and spine morphology, as well as size at maturity and maximum disc width. The two species of Manta are sympatric in some locations and allopatric in other regions. A visual key was constructed which highlights the conspicuous, diagnostic features of the two species using data collected throughout their respective geographical ranges. A third, putative species, referred to here as Manta sp. cf. birostris, in the Atlantic may be distinct from M. birostris, but further examination of specimens is necessary to clarify the taxonomic status of this variant manta ray. The results of this study will aid in the differentiation of members of this genus both in the field and in preserved specimens. The splitting of this long-standing monospecific genus will help to highlight the specific threats facing the different species of Manta (e.g. targeted fishing, bycatch fisheries, boat strikes and habitat degradation) and will ultimately assist in the correct assessment of their respective worldwide conservation status.
Article
Mobula thurstoni was the most abundant (58% of the catch), followed by M. japanica (30%), M. munkiana (9%), and M. tarapacana (3%). The study area served as a nursery ground for M. thurstoni, a summer feeding and mating ground for M. thurstoni and M. japanica, and a wintering ground for M. munkiana and young M. thurstoni. Data on size, weight, sex ratio, life history, seasonality, feeding habits, behavior, habitat, and symbionts are presented. Size segregation was a common feature of M. thurstoni, M. japanica and M. munkiana. Summer prey were almost exclusively the euphausiid Nyctiphanes simplex; the mysid Mysidium sp. dominated in winter. -from Author
Article
China is one of the largest consumers of wild animals for food and traditional Chinese medicine in the world. A large volume of illegal trade has been recorded in the primary cities, such as Hong Kong and Guangzhou, but the wildlife markets in secondary Chinese cities have not been investigated. This study was carried out in 7 cities in Guangdong and Guangxi provinces. Wildlife trade data were collected using semi-structured interview, observation, and market survey. The study documented the selling of 97 animal species, >7,000 individuals. The most frequently used animal groups by quantity were reptiles (51%), followed by birds (21%) and mammals (10%). Of the reported species, 23% were threatened, including 1 species critically endangered and 12 species endangered. In this study, there were 19 species observed that are recognized by the Convention on International Trade in Endangered Species (CITES). The results show that the animals originated not only from south China but also Indochina and Southeast Asia. Our survey also verified that Guangzhou and Hong Kong are not the only wildlife markets in South China. A large volume of illegal trade also is occurring in secondary cities in South China.
Article
In the present study 15 samples of Chinese therapeutic foods and herbs that are frequently consumed by people in both the East and West are analyzed, for the content of cadmium, mercury, lead, arsenic, cuprum and zinc, by atomic absorption spectrophotometer. The results showed that the highest mean value for Cd(0.49 mg·kg-1), Hg(0.34 mg·kg-1), Pb(9.01 mg·kg-1), As(3.26 mg·kg-1), Cu(33.56 mg·kg-1) and Zn(38.32 mg·kg-1) were found in Radix Salviae Miltitorrhizae, Radix Puerariae, Radix Salviae Miltitorrhizae , Radix Sophorae Flavescentis , Fructus Crataegi , Herba andrographis , respectively. The Cd levels of two samples and Cu levels of one sample were found to be higher than the recommended values of Food and Drug Administration (FDA) and World Health Organization (WHO), and may constitute a health hazard for consumers. Mercury, lead, and arsenic levels of one sample were higher than the recommended limit of China Pharmacopoeia, but it were below the WHO and FDA. All other heavy metals in other medicinal plants were found below the recommended tolerable limits.