Content uploaded by Biju Kumar
Author content
All content in this area was uploaded by Biju Kumar on Aug 18, 2021
Content may be subject to copyright.
© Department of Aquatic Biology & Fisheries, University of Kerala
Journal of Aquatic Biology & Fisheries | 2021 | 9 | pp. 1-11
ISSN 2321–340X
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in
South Kerala, India
Biju Kumar, A.1, Nisanth, H.P.1*, Vishnuraj, R.S.1 and Dipani Sutaria2
1Department of Aquatic Biology & Fisheries, University of Kerala, Thiruvananthapuram 695 581, Kerala, India
2College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
*Email: nisanthhp@gmail.com
Keywords: Marine mammal, Balaenoptera edeni, Balaenoptera musculus, Orcinus orca, Neophocaena phocaenoides,
Stenella coeruleoalba, Bushmeat, DNA barcode
Abstract
Received on: 25-10-2020; Revised on:01-02-2021; Accepted on: 02-02-2021
This paper reports cetacean stranding events along Kerala coast during 2017 to 2019 of Bryde’s whale (Balaenoptera edeni), blue
whale (Balaenoptera musculus), killer whale (Orcinus orca) and Indo-Pacific finless porpoise (Neophocaena phocaenoides)
identified through morphological approach. DNA barcoding using mitochondrial COI gene confirmed the identification of B. edeni
and B. musculus. The bushmeat trade involving striped dolphins (Stenella coeruleoalba) is also photo documented here. The
paper affirms the need to form cetacean stranding response programs to build a scientific baseline for cetacean conservation and
research, monitor threats to cetaceans and curtail the cetacean meat trade.
1. Introduction
Marine mammals are a charismatic and diverse group of
marine vertebrates and among these, cetaceans, including
whales, dolphins and porpoises, are the most commonly
distributed groups (Berta et al., 2015). Marine mammals
play a pivotal and irreplaceable role in the marine
ecosystem and are considered marine engineers (Roman
et al., 2014; Albouy et al., 2020) as apex predators in the
trophic marine food web (Jefferson et al.,1993; Zhao et
al., 2017). Out of the 85 species reported globally, 40
species occur in the Indian Ocean and based on the
stranding and sighting records, around 30 species are
reported from Indian waters (Jefferson et al., 2008; Perrin
et al., 2009; Vivekanandan and Jayabaskaran, 2012). The
species composition may vary according to the oceanic
condition and biological composition (Walker et al., 2005).
Strandings of cetaceans are a global phenomenon, washed
ashore either dead, ill or alive (Geraci and Lounsbury,
2005; Alvarado-Rybak et al., 2020). The primary reasons
for cetacean stranding include natural causes such as the
alteration in climatic events, oceanic conditions, loss of
habitat, disease and infections and anthropogenic reasons
such as ship strikes, pollution, acoustic disturbances,
hunting, bycatch and the incidental and intentional
activities of fisheries (Berman-Kowalewski et al., 2010;
Bogomolini et al., 2010; Groom and Coughran, 2012;
Trianni and Tenorio, 2012; Bengil et al., 2020). These
threats cause direct effects such as mortalities and injuries
as well as indirect effects like long term physiological
and behavioural changes (Avila et al., 2018). According
to Coombs et al. (2019), stranding events have increased
annually since 1980.
Even though marine mammals are protected under Indian
Wildlife (Protection) Act of 1972, many species of
cetaceans, especially dolphins, are intentionally hunted
for bushmeat, bait and medicine (Yousuf et al., 2009;
Porter and Lai, 2017). Anderson et al., (2020) estimated
that just in the Indian Ocean Tuna gillnet fisheries, caught
an estimated cumulative total of 4.1 million small
cetaceans between 1950 and 2018, with Indian gillnet
fisheries being in the top three of the nine Indian ocean
countries incidentally catching cetaceans. In India, the
estimated number of cetaceans bycaught annually is
between 9,000-10,000 (MoEFCC, 2021), demanding
better management of stranding of these marine mega
fauna.
This paper describes four cetacean stranding events and
bushmeat trade that occurred during 2017 to 2019 along
Kerala coast with a confirmation of identification for a
blue whale and Bryde’s whale through DNA barcoding,
and also describes illegal trade of dolphin meat for local
consumption.
2. Materials and Methods
2.1 Coastal and Market Visits
All the major fishing harbours and selected fish landing
centers of Kerala coast were visited to observe if the meat
trade of cetaceans was taking place. Coastal NGOs and
active fishermen in the area were also involved to obtain
information on the dolphin bushmeat trade (Table 1). A
network of informants was created along the coastal
villages to inform about cetacean strandings. Any
cetaceans landed were photo-documented. Species were
identified by assessing the body shape, size, position and
shape of dorsal fin, colour patterns and shape of the head,
flippers, and fluke. The key characters and the
morphometric measurements and meristic characteristics
of the stranded species were recorded (Jefferson et al.,
1993, 2008; Geraci and Lounsbury, 2005). Tissue samples
were collected and preserved in ethanol for molecular
analysis, wherever possible.
Journal of Aquatic Biology & Fisheries
2
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in South Kerala, India
2.2 DNA barcoding protocol
DNA barcoding by sequencing of the mitochondrial
marker gene cytochrome oxidase 1 (CO1) was used to
confirm baleen whale species identification. Genomic
DNA was isolated from the tissues using NucleoSpin®
Tissue Kit (Macherey-Nagel) following instructions from
the manufacturer, and cox1 gene was amplified using
universal primers LCO (GGT CAA CAA ATC ATA AAG
ATA TTG G) and HCO (TAA ACT TCA GGG TGA
CCAAAA AAT CA) (Folmer et al., 1994). PCR product
was visualised on 1% agarose gels, and the most intense
products were selected for sequencing. The sequencing
reaction was done in a PCR thermal cycler (GeneAmp
PCR System 9700, Applied Biosystems) using the BigDye
Terminator v3.1 Cycle Sequencing Kit (Applied
Biosystems, USA). The sequence quality was checked
using Sequence Scanner Software v1 (Applied
Biosystems). Sequence alignment and editing of the
obtained sequences were carried out using Geneious Pro
v5.1 (Drummond et al., 2010).
Basic Local Alignment Search Tool (BLAST) was used
for sequence similarity search and species identification
using GenBank DND sequence data bank (Altschul et
al., 1990). Phylogenetic and molecular evolutionary
analyses were done by MEGA version 7 (Kumar et al.,
2016). Maximum likelihood tree for the cox1 gene was
constructed with a bootstrap value of 1000 times to get
percentage bootstrap values for branch points.
No Species ID Location Date Size Sex District, State
1Balaenoptera edeni Puthukurichi 25-09-2018 11.30 m - 1 Thiruvananthapuram, Kerala
(8°36’15.4"N,
76°48’32.1"E)
2Orcin usorca Perumathura 04-08-2019 4.65 m Male 1 Thiruvananthapuram, Kerala
(8°37’04.5"N,
76°47’52.8"E)
3Neophocaena Veliyaveli 16-08-2019 0.86 m Female 1 Thiruvananthapuram, Kerala
phocaenoides (8°30’33.1"N,
76°53’07.5"E)
4Balaenoptera musculus Veliyaveli 29-08-2019 16.50 m - 1 Thiruvananthapuram, Kerala
(8°30’33.1"N,
76°53’07.5"E)
Market
5Stenella coeruleoalba Vizhinjam 03-03-2017 1.10m - 2 Thiruvananthapuram, Kerala
Fishing Harbour (approx.)
No. of
individuals
Table 1. The details of stranded cetaceans along Kerala coast recorded during 2017 to 2019
3. Results
3.1 Morphological Studies
The cetaceans in the Thiruvananthapuram district of
Kerala coast recorded during 2017 to 2019 include two
species of baleen whales, one Indo-Pacific finless porpoise,
one killer whale and two striped dolphins landed for
bushmeat (Table 1). The examination of morphology and
meristic characters confirmed the baleen whale from
Puthukurichi region is a Bryde’s whale (Balaenoptera
edeni) (Fig. 1 A, B; Table 2). The cetacean carcass in
Veliyaveli region of Thiruvananthapuram coast was
tentatively identified as the blue whale (Balaenoptera
musculus) (Fig. 1 C, D; Table 3) and later confirmed
through molecular studies. The morphological and
morphometric studies confirmed that the cetacean stranded
at Perumathura region is killer whale (Orcinusorca)
(8°37’04.5"N, 76°47’52.8"E) (Fig. 2 A-C; Table 4), and
the second cetacean from Veliyaveli is Indo-Pacific finless
porpoise(Neophocaena phocaenoides) (Fig. 2 D; Table
5).
3.2 Molecular analysis
The mitochondrial marker gene, CO1 was successfully
amplified and sequenced for both baleen whales. The
blast analysis of the sequences of MW564080 and
MW564081 showed 99% similarity with sequence of
Balaenoptera musculus and that of MW571086 showed
99% similarity with Balaenoptera edeni available in
GenBank, re-confirming the identity of these strandings.
The correlation of sequences obtained during this study
was inferred using the Maximum Likelihood (ML)
method. Furthermore, it was grouped with the sequence
of identical species Balaenoptera musculus sequence
(NC_001601, X72204) and Balaenoptera edeni
(JN_190944) obtained from NCBI-GenBank.
The genetic distance of the sequences obtained during
the study and the identical species of Balaenoptera
musculus sequences in GenBank is 0.002 to 0.004. In
Maximum Likelihood tree of cox1 gene, it is aligned with
Balaenoptera musculus sequence (NC_001601, X72204)
from the GenBank and form a separate clade with the
sequence of other species of the same genus. The sequences
of Balaenoptera edeni in the present study has been
aligned with similar species with GenBank accession
numbers AB_201258, JN_190945, MT_895690,
JN_190944, and MT_895691, with a genetic distance of
0.00 to 0.002. The DNA sequencing thus confirmed the
identity of two stranded cetacean species as Balaenoptera
musculus and Balaenoptera edeni.
3.3 Dolphins as Bushmeat
Along with cetacean stranding events, the landings of
cetaceans also occur for meat consumption along Kerala
coast. Our survey documented several cases of dolphin
meat trade in Thiruvananthapuram district of Kerala coast,
involving Indian Ocean humpback dolphin and Indo-
Journal of Aquatic Biology & Fisheries 3
Biju Kumar et al.
Fig. 1. Stranding of cetaceans in Thiruvananthapuram district, Kerala:
A, B. Balaenoptera edeni; C, D. Balaenoptera musculus
Pacific finless porpoise during 2017-2019 period. The sale
of two striped dolphins (Stenella coeruleoalba) caught
by the local fishermen in the local market at Vizhinjam
fishing harbour was photo documented (Fig. 4 A-E) on
03.03.2017. The observations and interaction with NGOs
and fishermen revealed that the demand for dolphin meat
is common in the local fish market and the individuals
caught were immediately processed by cutting off their
head, flippers and fluke to avoid visual identification (Fig.
4 A-E).
In Vizhinjam and Kovalam there are middlemen involved
in the business of bushmeat trade and the frequent
transport of dolphins to illegal markets near Kollengode
in Kerala-Tamil Nadu border have also been observed
during the survey. The middlemen and the fishermen are
always on the vigil and stop any unknown person in the
coast with a camera. Since the demand for bushmeat is in
southern Kerala most of the products are sold in the local
market itself. In general, fishermen are aware of the
endangered status of dolphins and other marine mammals,
and there are instances of fishermen releasing the species
caught in the nets back to the sea.
Journal of Aquatic Biology & Fisheries
4
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in South Kerala, India
Table 2. Morphometry of a Bryde’s whale (Balaenoptera edeni) washed ashore at
Puthukurichi, Thiruvananthapuram district, Kerala
Table 3. Morphometry of a blue whale (Balaenoptera musculus) washed ashore at
Veliyaveli, Thiruvananthapuram district, Kerala
No. Measurement Metre
1 Length, total (tip of the upper jaw to the deepest part of notch between flukes) 16.5
2 Length, tip of the upper jaw to centre of eye -
3 Length of gape (tip of the upper jaw to angle of gape) -
4 Length, tip of upper jaw to blowhole along midline -
5 Length, tip of upper jaw to anterior insertion of flipper -
6 Length, tip of upper jaw to tip of dorsal fin 13.5
7 Length of flipper (anterior insertion of tip) 2.15
8 Width, flipper (maximum) 0.78
9 Height of dorsal fin (fin tip to base) 0.44
10 Fluke span 2.26
11 Width of flukes (distance from nearest point on anterior border of fluke notch) 0.96
Table 4. Morphometry of Killer whale (Orcinusorca) washed ashore at
Perumathura, Thiruvananthapuram district, Kerala
No. Measurement Metre
1 Length, total (tip of the upper jaw to the deepest part of notch between flukes) 4.65
2 Length, tip of the upper jaw to centre of eye 0.86
3 Length of gape (tip of the upper jaw to angle of gape) 0.74
4 Length, tip of upper jaw to blowhole along midline 0.98
5 Length, tip of upper jaw to anterior insertion of flipper 1.37
6 Length, tip of upper jaw to tip of dorsal fin -
7 Length of flipper (anterior insertion of tip) 1.1
8 Width, flipper (maximum) 0.68
9 Height of dorsal fin (fin tip to base) -
10 Fluke span -
11 Width of flukes (distance from nearest point on anterior border of fluke notch) -
No. Measurement Metre
1 Length, total (tip of the upper jaw to the deepest part of the notch between flukes) 11.3
2 Length, tip of the upper jaw to centre of eye 3.1
3 Length of gape (tip of the upper jaw to angle of gape) 4.78
4 Length, tip of upper jaw to blowhole along midline 4.32
5 Length, tip of upper jaw to anterior insertion of flipper 5.96
6 Length, tip of upper jaw to tip of dorsal fin 8.53
7 Length of flipper (anterior insertion of tip) 2.43
8 Width, flipper (maximum) 0.65
9 Height of dorsal fin (fin tip to base) 1.33
10 Fluke span 3.98
11 Width of flukes (distance from nearest point on anterior border of fluke notch) 1.27
Table 5. Indo-Pacific Finless Porpoise (Neophocaena phocaenoides) washed ashore at
Veliyaveli, Thiruvananthapuram district, Kerala
- Not measured
Note: The porpoise has signs of rope/net around the girth of its neck, showing that it could have got
entangled in a multifilament large mesh net such as shark nets.
No. Measurement Metre
1 Length, total (tip of the upper jaw to the deepest part of notch between flukes) 0.86
2 Length, tip of the upper jaw to centre of eye 0.085
3 Length of gape (tip of the upper jaw to angle of gape) 0.065
4 Length, tip of upper jaw to blowhole along midline 0.18
5 Length, tip of upper jaw to anterior insertion of flipper 0.19
6 Length, tip of upper jaw to tip of the dorsal fin 0
7 Length of the flipper (anterior insertion of the tip) 0.18
8 Width, flipper (maximum) 0.095
9 Height of dorsal fin (fin tip to base) 0
10 Fluke span 0.14
11 Width of flukes (distance from nearest point on anterior border of fluke notch) 0.065
Journal of Aquatic Biology & Fisheries 5
Biju Kumar et al.
Fig. 2. Stranding of cetaceans in Thiruvananthapuram district, Kerala:
A-C: Orcinusorca; D: Neophocaena phocaenoides
Fig. 3. Molecular phylogenetic analysis of Balaenoptera species stranded in Kerala coast by Maximum Likelihood method
Journal of Aquatic Biology & Fisheries
6
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in South Kerala, India
In our study the reasons for the stranding are unknown
and seems complicated to access the cause of death from
the carcasses due to the highly decomposed condition,
making it impossible to carry out a necropsy. Our paper
shows that small sized dolphins such as Indian Ocean
humpback dolphin, Indo-Pacific finless porpoise, and
Striped dolphins and perhaps other Stenella species are
being consumed as bushmeat locally. In the case of the
Indo-Pacific finless porpoise that was washed ashore, the
sign of entanglement is evident. But more often than not,
cause of death and species identification are difficult due
to high level of decay and decomposition of body parts
(Aneesh Kumar et al., 2019). Of the four specimens in
this paper only the Indo-Pacific finless porpoise could be
used for complete morphometric and meristic characters.
4. Discussion
Fig. 4. Processing of striped dolphins (Stenella coeruleoalba) in the local market at Vizhinjam, Kerala coast, India
In the case of blue whale and Byrde’s whale, the specimens
were in highly putrefied in condition, and the
morphometric data are insufficient in confirming the
species identification. In this scenario, the sequencing of
mitochondrial marker gene, cox 1, provided a reliable
species identification tool in the study. The stranding of
Balaenoptera edeni has been confirmed earlier also from
Kerala coast through DNA barcoding (George et al., 2010;
Biju Kumar et al., 2012).
The bushmeat trade of cetaceans is small, facilitated by a
minority of fishermen but supported by the middlemen
and so continues in southern Kerala. The ongoing illegal
trade of dolphin bushmeat in south Kerala is a matter of
great concern and requires urgent intervention of social
scientists and policy makers.
Journal of Aquatic Biology & Fisheries 7
Biju Kumar et al.
Past records of marine mammal strandings show the
presence of three species of baleen whales, including blue
whales and Bryde’s whales along the Kerala coast, with
dead and live stranding and live sightings reported
(Sutaria et al., 2016, 2017; Sutaria, 2018, 2019; Marine
Mammal Research and Conservation Network of India,
2020). Based on past records, confirmed report of Killer
whale is for the first time from Kerala coast in the present
study; there were eight earlier records of blue whale and
seven reports of Bryde’s whale strandings from Kerala
coast (Table 6). Nameer (2016) updated marine mammal
(cetacean and sirenian) list of Kerala and considered 31
species under seven families and two orders (Sirenia and
Cetacea).
Killer whale (Orcinus orca) is a cosmopolitan species
widely distributed, migrating in all the seas and oceans
(Ford, 2002). Along the west coast of India, they are
sighted every year between February and June in recent
years (Marine Mammal Research and Conservation
Network of India, 2020). Studies have shown that there is
movement of individuals between Sri Lanka and northwest
Arabian Sea. Maintaining sighting data or tissue samples
from strandings will help elucidate the migratory path of
the different killer whale stocks in the northern Indian
Ocean. Bryde’s and blue whales are present all through
the year in the coastal waters of the west coast, with a
possibility of resident populations in the region.
Indo-Pacific finless porpoise strandings have been
recorded all along the Indian coast, and are the most
frequently caught for meat (Kumarran, 2012; Monalisha
and Patterson, 2014; Marine Mammal Research and
Conservation Network of India, 2020). In the present
study, the obtained dead specimen was a calf or juvenile
female individual and the cause of death is prolonged
entanglement in the fishing net.
Peltier et al. (2013) reported that there would be a seasonal
periodicity in the stranding events. An isolated population
of the blue whale is observed year-round in Indian and
Sri Lankan waters (Mikhaley, 2000). Usually, South-west
monsoon currents induce upwellings in India’s southwest
region, which leads to plankton blooms, attracting marine
mega fauna such as whales, especially blue whales and
Bryde’s whales (Anderson et al., 2012). During the present
study, all the carcasses were recorded in the months August
– November just after the South-west Monsoon showing
that the southern coast of India could be influenced by
the currents bringing ashore dead animals.
The ecological reasons for stranding and mortalities vary
and include global warming, changes in the bottom
topography, coastal configuration, oceanographic events,
extreme conditions in the environment and biological
reasons such as infectious diseases and senescence (Perrin
and Geraci, 2002; Williams, 2018). Global warming alters
the habitat, foraging grounds and prey composition of
cetaceans which adversely affect their survival and leads
to the loss of functional diversity (Albouy et al., 2020).
Deaville and Jepson (2011) reported starvation due to
decreased food supply and malnutrition, leading to the
death of cetaceans and leading to mass stranding. The
gas embolic syndrome due to the sudden movements across
the depth, especially by rapid ascent and decompression
sickness as an impact of sonar, also leads to fatal damages,
which leads to the stranding of cetaceans (Jepson et al.,
2003; Fernandez et al., 2005). All these sources of sound
pollution led to impaired hearing which affects in
receiving the echolocation signals and also in social
vocalisation and pose a threat for their survival (Gomez
et al., 2016). Exposure to biotoxins from the harmful algal
blooms (HAB) also adversely affects the cetacean survival
(Fire et al., 2011). Various oceanographic disturbances
such as storm and currents, may lead to disorientation
and exhaustion, leading to cetacean stranding (MacLeod
et al., 2004; Bogomolni et al., 2010).
Commercial fisheries is a significant threat, due to target
catch and bycatch (Ozturk et al., 2001; Bengil et al.,
2020). Coastal fisheries, particularly gillnets, purse seine,
and discarded ghost nets, lead to the entanglement of small
cetaceans like dolphins. On some occasions, baleen whales
also entangled in the nets, leading to incidental mortality.
The escaped individuals with the remnants of debris may
face locomotion problems and foraging efficiency
(Agrawal and Alfred, 1999; Reeves et al., 2013).
According to Anderson (2014), small cetaceans like
dolphins fail to detect gillnets and get entangled, which
is a common issue. Reeve et al. (2013) and Muralidharan
(2018) reported that fishermen consider cetaceans to be
nuisances because of the problems they create for the
artisanal fisheries and the unintentional bycatch damages
the fishing gear, while the dead cetaceans are discarded
at sea. There are no proper systems to monitor cetacean
bycatch, or mitigation measures to reduce this, and thus
there I inefficiency in accounting the impact of fisheries
on cetaceans.
Pollution and plastic contamination, especially the
ingestion and entanglement of marine debris, have also
been attributed to cetacean death and subsequent stranding
(Simmonds, 2012; Baulch and Perry, 2014).
Laist et al. (2001) and Berman-Kowalewski et al. (2010)
suggest that whales are the most affected species of ship
strikes and severely impacted on whales with a restricted
population status. According to New et al. (2015) many
cetacean species, especially whales, respond to the ship
with surface-active such as breathing or basking and the
avoidance behaviours and sometimes it may lead to ship
strike. There is limited knowledge about the actual
conflicts between cetaceans and shipping interactions
(VanWaerebeek et al., 2007).
Around the world, in coastal areas reported there is an
overlap between strandings and high productivity which
supports both cetacean diversity as well as the human
livelihood, and leads to increase in human- marine
mammal conflicts. Similarly, the overlap between shipping
lanes and cetacean habitat leads to increased strike rates
(Branch et al., 2007; De Vos et al., 2016).
Regarding the demand of meat of dolphins, thousands of
small cetaceans are directly hunted in the Southeast and
East Asian countries (Altherr et al., 2018). In India,
cetacean species are protected under the Wildlife
(Protection) Act of 1972. With vigorous enforcement of
law towards the conservation of marine mammal species,
Journal of Aquatic Biology & Fisheries
8
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in South Kerala, India
Table 6. Historical reports of baleen whales and killer whale along Kerala coast
Name of person submitted observation Date of record Species
Biju Kumar, A. 04-08-2019 Killer whale
Nisanth, H.P. 29-08-2019 Unidentified baleen whale
Nameer, P.O. 26-04-2019 Unidentified baleen whale
Biju Kumar, A. 25-09-2018 Bryde’s whale
Nisanth, H. P. 17-09-2018 Unidentified baleen whale
Sutaria D. 12-07-2016 Bryde’s whale
Baby, K.G. 29.05.2014 Unidentified Baleen whale
Panicker, D. 19-05-2013 Bryde’s whale
Kumaran Sathasivam 2010 Bryde’s whale
Shanis, R., Akhilesh, K.V. and 27-02-2010 Blue Whale
Prakashan, D.
George, S., Meenakshi, K. and 27-09-2009 Bryde’s whale
Bijukumar, A.
Sathasivam, K. 25-06-2009 Bryde’s whale
Sathasivam, K. 18-10-1996 Blue whale
Baby, K.G. 1996 Unidentified baleen whale
Baby, K.G. 29-10-1995 Blue whale
James, P.S.B.R., Menon, N.G. and 02-05-1993 Blue whale
Pillai, N.G.K.
Lal Mohan, R. S. 29-09-1988 Blue whale
Somasekharan Nair, K.V. and 02-09-1985 Blue whale
Jayaprakash, A.A.
Joel J.J. and Joseph,M. 24-04-1981 Unidentified baleen whale
Lal Mohan, R.S. 02-07-1979 Bryde’s whale
Venkatraman, G. and Girijavallabhan, K.G. 25-05-1966 Blue whale
Chacko, P.I. and Mathew, M.J. 10-12-1954 Unidentified baleen whale
Chacko, P.I. and Mathew, M.J. 01-09-1951 Unidentified baleen whale
Chacko, P.I. and Mathew, M. J. 01-04-1949 Unidentified baleen whale
Moses, S.T. 01-05-1947 Unidentified baleen whale
Jacob, P.K. and Devidas Menon, M. 28-01-1947 Unidentified baleen whale
Poduval, R.V. 04-02-1937 Unidentified baleen whale
Moses, S.T. 01-03-1935 Unidentified baleen whale
Moses, S.T. 1934 Unidentified baleen whale
Moses, S.T. 1927 Blue Whale
Moses, S.T. 1926 Unidentified baleen whale
Moses, S.T. 1924 Unidentified baleen whale
Moses, S.T. 1858 Unidentified baleen whale
Moses, S.T. 1848 Unidentified baleen whale
the poaching of cetaceans is frequent in the coast of Kerala
and is mainly associated with demand from the local
markets.
According to Kumarran (2012), small cetaceans like
Indian Ocean humpback dolphin and Indo-Pacific finless
porpoise, are frequently consumed. This study also
recorded the meat trade involving Indian Ocean humpback
dolphin and Indo-Pacific finless porpoise, though photo
documentation and case study was limited to the bushmeat
trade of Stenella coeruleoalba. Given that Kerala has
reported greater diversity of small dolphins in the past, it
is worrisome that only striped dolphins seem to be landed
and consumed frequently; and this could be a sign of
decreasing diversity and population sizes of other Stenella
species in southern waters of India.
Millions of these small cetaceans are hunted annually
worldwide for meat for human consumption, bait use in
fisheries and oil for medicine despite the minimal
protection, which increases the human- marine mammal
conflicts and also the bushmeat trade become the major
anthropogenic threat to many of the small cetaceans
(Clapham and Waerebeek, 2007; Mintzer et al., 2018).
The present study highlights the trade of the striped
dolphins in the open markets of southern Kerala. The
unusual practice is of processing of meat by chopping off
its fluke, flippers, fin and head at the landing centre and
selling of the processed meat as fish meat which clearly
shows that the fishermen know that the cetacean hunting
is illegal.
All these pressures will affect marine mammal population
adversely, and as a result, most of the species are currently
included in the threatened category (Perrin et al., 2009).
As one of the apex predators which plays a crucial role in
maintaining biomass and stability marine ecosystem
(Bowen, 1997), providing baseline information regarding
stranding events and the evaluation of the cause of
(Sources: http://www.marinemammals.in/database/sightings-a nd-strandings/; http://www.cmfri.org.in/
MammalStrandingWithClustering16/StrandingWithClustering16.html#5/16.046/78.157)
Journal of Aquatic Biology & Fisheries 9
Biju Kumar et al.
mortalities along with the trends in population plays a
crucial component in the assessment of the status of the
cetaceans (De Oliveira et al., 2012). Knowledge regarding
the status and population trends is feeble (Evans et al.,
2012). The information from the stranding data will play
a reasonable role in assessing the knowledge gaps and
monitoring the various aspects of marine mammal life.
The single species stranding events frequently occur along
the coasts of Kerala. In most of the cases, the reasons for
stranding are unknown. However, stranding events shows
that the Arabian sea supports the lives of marine mammal
species and the stranding events highlight the need for
undertaking the extensive studies regarding the
distribution and behaviour of the cetacean species which
is still unclear in the Indian scenario. Along with the
stranding events, the cases of trade and local demand for
cetacean meat also shows an urgent need for the
implementation of laws and the need for creating
awareness in public regarding the importance of cetaceans.
Very recently Ministry of Environment, Forest and Climate
Change (MoEFCC), Government of India has released
guidelines for the stranding management of marine mega
fauna in India, with a proposal to improve inter-sectoral
collaboration and coordination between Government and
Acknowledgements
We thank the Kerala Forests and Wildlife Department for
the research permission to study the marine mammals of
Kerala coast (Order No. KFDHQ/28764/2018-CWW /WL
10 dated 16.11.2018- KF&W). Nisanth thanks DST for
INSPIRE fellowship and Vishnuraj thanks KSCSTE for
Junior Research Fellowship for the doctoral work.
civil society for sharing of data, research and conservation.
The proposal also include establishment of National
Stranding Centre (NSC), State Stranding Centre (SSC),
Local Stranding Networks, and Rapid Response Team.
We suggest developing a mobile app for reporting the
occurrence and stranding of marine mammals along
Kerala coast and for reporting any incidence of bushmeat
trade. The possibility of using the Biodiversity
Management Committees (BMCs) of State Biodiversity
Boards may also be explored to inform stranding and trade
of scheduled species in coastal villages. The services of
fisherfolk and citizen scientists may be better utilized in
survey and monitoring of marine mammals and other
protected marine species along Indian coast. Above all,
there is an urgent need to strengthen awarenss and media
campaign on protected marine species of India.
Agrawal, V.C. and Alfred, J.R.B. 1999. Handbook on Whales Dolphins and Dugong from Indian Seas, i-iv, 1-150. Zoological
Survey of India, Kolkata.
Albouy, C., Delattre, V., Donati, G., Frölicher, T.L., Albouy-Boyer, S., Rufino, M., Pellissier, L., Mouillot, D. and Leprieur, F.
2020. Global vulnerability of marine mammals to global warming. Scientific Reports, 10: 548; https://doi.org/10.1038/s41598-
019-57280-3
Altherr, S., Hodgins, N., Fisher, S., O’connell, K. and Schubert, D.J. 2018. Small cetaceans, big problems - A global review of the
impacts of hunting on small whales, dolphins and porpoises PRO Wild. Animal Welfare Institute, Chippenham.
Altschul, S.F., Gish, W., Miller, W., Myers, E.W. and Lipman, D.J. 1990. Basic local alignment search tool. Journal of Molecular
Biology, 215: 403-410.
Alvarado-Rybak, M., Toro, F., Escobar-Dodero, J., Kinsley, A.C., Sepúlveda, M. A., Capella, J., Azat, C., Cortés-Hinojosa, G.,
Zimin-Veselkoff, N. and Mardones, F.O. 2020. 50 years of cetacean strandings reveal a concerning rise in Chilean Patagonia.
Scientific Reports, 10: 9511; https://doi.org/10.1038/s41598-020-66484-x 1
Anderson, C. A., Branch, T.A., Alagiyawadu, A., Baldwin, R. and Marsac, F. 2012. Seasonal distribution, movements and
taxonomic status of blue whales (Balaenoptera musculus) in the northern Indian Ocean. Journal of Cetacean Resources and
Management, 12: 203- 218.
Anderson, R. C. 2014. Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean. IPNLF Technical Report 2,
International Pole and Line Foundation, London, 133pp.
Anderson, R. C., Herrera, M., Ilangakoon A.D., Koya, K.M., Moazzam, M., Mustika, P.L., and Sutaria, D.N. 2020. Cetacean
bycatch in Indian Ocean tuna gillnet fisheries. Endangered Species Research. 41:39-53. https://doi.org/10.3354/esr01008
Aneesh Kumar, K.V., Baby, S.T., Dhaneesh, K.V., Manjebrayakath, H., Saravanane, N. and Sudhakar, M. 2019. A Stranding
Record of Dwarf Sperm Whale Kogia sima in Lakshadweep Archipelago, India and its Genetic Analogy by Molecular Phylogeny.
Thalassas, 35: 239–245; https://doi.org/10.1007/s41208-018-0115-9
Avila, I.C., Kaschner, K., and Dormann, C. F., 2018. Current global risks to marine mammals: Taking stock of the threats.
Biological Conservation, 221: 44–58.
Baulch, S. and Perry, C. 2014. Evaluating the impacts of marine debris on cetaceans. Marine Pollution Bulletin, 80: 210–221.
Bengil, F., Ozaydýnlý, M. and Bengal, E.G.T. 2020. An evaluation on interaction of Cetaceans with fisheries in the seas around
Turkey. Journal of Wildlife and Biodiversity, 4(3): 8-17; 10.22120/jwb.2020.124829.1131
Berman-Kowalewski, M., Gulland, F. M. D., Wilkin, S., Calambokidis, J., Mate, B., Cordaro, J., Rotstein, D., St. Leger, J.,
Collins, P., Fahy, K. and Dover, S. 2010. Association between Blue Whale (Balaenoptera musculus) Mortality and Ship
Strikes along the California Coast. Aquatic Mammals, 36. 59-66; 10.1578/AM.36.1.2010.59.
Berta, A., Sumich, J. and Kovacs, K. 2015. Marine Mammals: Evolutionary Biology: Third Edition. Academic Press. 1-726.
Biju Kumar, A., Jijith, S.S., Suresh Kumar, U. and George. S. 2012. DNA barcoding of the Bryde’s Whale Balaenoptera edeni
Anderson (Cetacea: Balaenopteridae) washed ashore along Kerala coast, India. Journal of Threatened Taxa, 4(3): 2436–2443.
Bogomolni, A.L., Pugliares, K.R., Sharp, S.M., Patchett, K., Harry, C.T., LaRocque, J.M., Touhey, K.M. and Moore, M. 2010.
Mortality trends of stranded marine mammals on Cape Cod and southeastern Massachusetts, USA, 2000 to 2006. Diseases of
Aquatic Organisms. 88: 143–155.
Bowen, W. D. 1997. Role of marine mammals in aquatic ecosystems. Marine Ecology Progress Series, 158: 267-274.
Branch, C.A., Stafford, K.M., Palacios, D.M., Allison, C., Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A., Vernazzani,
B.G., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, M., Matsuoka, K., Mikhalev, Y., Miyashita, T., Morrice, M., Nishiwaki,
5. References
Journal of Aquatic Biology & Fisheries
10
Records on Stranding Events of Cetaceans and Illegal Trade of Dolphins in South Kerala, India
S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N., Best, P.B., Borsa, P., Brownell, R.L., Childerhouse, S., Findlay,
K., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, D.K., Ljungblad, B., Maughan, B., McCauley, R.D., McKay, S.,
Norris, T.F., Oman Whale and Dolphin Research Group, Rankin, S., Samaran, F., Thiele, D., Van Waerebeek, K. and Warneke,
R.M. 2007. Past and present distribution, densities and movements of blue whales in the Southern Hemisphere and northern
Indian Ocean. Mammal Reviews, 37(2): 116–75.
Clapham, P. and Van Waerebeek, K. 2007. Bushmeat and bycatch: the sum of the parts. Molecular Ecology, 16: 2607–2609
CMFRI 2020. http://www.cmfri.org.in/MammalStrandingWithClustering16/StrandingWithClustering16.html#5/16.046/78.157.
Electronic Version accessed on 04 August 2020.
Coombs, E.J., Deaville, R., Sabin, R.C., Allan, L., O’Connell, M., Berrow, S., Smith, B., Brownlow, A., Doeschate, M.T.,
Penrose, R., Williams, R., Perkins, M.W., Jepson, P.D. and Cooper, N. 2019. What can cetacean stranding records tell us? A
study of UK and Irish cetacean diversity over the past 100 years. Marine Mammal Science, 35: 10.1111/mms.12610.
De Oliveira, L.R., Fraga L.D. and Majluf P. 2012. Effective population size for South American sea lions along the Peruvian coast:
the survivors of the strongest El Nino event in history. Journal of the Marine Biological Association of the United Kingdom,
Editorial. 95. 1-3; 10.1017/S0025315414001738.
De Vos, A., Brownell, R., Tershy, B. and Croll, D. 2016. Anthropogenic Threats and Conservation Needs of Blue Whales,
Balaenoptera musculus indica, around Sri Lanka. Journal of Marine Biology, 1-12; 10.1155/2016/8420846.
Deaville, R. and Jepson, P.D. 2011. CSIP Final Report for the period 1st January 2005–31st December 2010. UK Cetacean
Strandings Investigation Programme: Report to the UK Department for Food and Rural Affairs and the Devolved Administrations.
Defra website. Available: http://randd.defra.gov.uk/Document.aspx?Document=FinalCSIPReport2005-
2010_finalversion061211released [1].pdf. Accessed 2013 Mar 11.
Drummond, A.J., Ashton, B., Buxton, S., Cheung, M., Cooper, A., Heled, J., Kearse, M., Moir, R., Stones-Havas, S., Sturrock, S.,
Thierer, T. and Wilson, A. 2010. Geneious v5.5. Available at http://www.geneious.com (accessed on 22 June 2020).
Evans, P., Pierce, G. and Wright, A. 2012. Marine mammal studies to address future challenges in conservation management
foreword. Journal of the Marine Biological Association of the United Kingdom, 92: 1639-1644; 10.1017/S0025315412001609.
Fernandez, A., Edwards, J.F., Rodriguez, F., Monteros, A.E., Herraez, P., Castro P., Jaber, J.R., Martin, V. and Arbelo, M. 2005.
Gas and fat embolic syndrome” involving a mass stranding of beaked whales (family Ziphiidae) exposed to anthropogenic
sonar signals. Veterinary Pathology, 42: 446 – 457.
Fire, S. E., Wang, Z., Byrd, M., Whitehead, H.R., Paternoster, J. and Morton, S.L. 2011. Co-occurrence of multiple classes of
harmful algal toxins in bottlenose dolphins (Tursiops truncatus) stranding during an unusual mortality event in Texas, USA.
Harmful Algae, 10(3): 330-336.
Ford, K.B.J. 2002. Killer Whale. In W. F. Perrin, B. Wursig and J. G. M. Thewissen (Eds.), pp. 1192–1197. Encyclopaedia of
Marine Mammals. Academic Press, San Diego.
George S., Meenakshi K and Biju Kumar A. 2010. Molecular taxonomy of marine mammals stranded along Kerala coast, India.
Current Science, 100 (1): 117-120.
Geraci, J.R. and Lounsbury, V. R. 2005. Marine Mammals Ashore: A Field Guide for Strandings. 2nd ed. National Aquarium in
Baltimore, Baltimore, 305pp.
Gómez, C., Lawson, J.W., Wright, A.J., Buren, A.D., Tollit, D., Lesage, V. 2016. A systematic review on the behavioural responses
of wild marine mammals to noise: the disparity between science and policy. Canadian Journal of Zoology, 94: 801–819.
Groom, C. and Coughran, D. 2012. Three decades of cetacean strandings in Western Australia: 1981 to 2010. Journal of the Royal
Society of Western Australia, 95: 63-76.
Jefferson, T.A., Leatherwood, S. and Webber, M.A. 1993. FAO Species Identification Guide, Marine Mammals of the World. FAO,
Rome, 320 pp.
Jefferson, T.A., Webber, M. A. and & Pitman, R.L. 2008. Marine Mammals of the World: A Comprehensive Guide to Their
Identification. Academic Press, New York, 616 pp.
Jepson, P.D., M. Arbelo, R. Deaville, R., Patterson, I.A.P., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herráez, P., Pocknell,
A.M., Rodríguez, F., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A. and Fernández, A.
2003. Gas-bubble lesions in stranded cetaceans. Nature, 425: 575-576; 10.1038/425575a.
Kumar, S., Stecher G., and Tamura, K. 2016. MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets.
Molecular Biology and Evolution, 33: 1870-1874.
Kumarran, R.P. 2012. Cetaceans and cetacean research in India. Journal of Cetacean Research and Management 12(2): 159–172.
MacLeod, C. D., Pierce, G. J. and Santos, M. B. 2004. Geographic and temporal variations in strandings of beaked whales
(Ziphiidae) on the coasts of the UK and the Republic of Ireland from 1800–2002. Journal of Cetacean Research and Management,
6: 79–86.
Marine Mammal Research and Conservation Network (2020). Mammal Research and Conservation Policy - Update From India.
International Whaling Commission Scientific Committee Meeting 68A, Nairobi, Kenya.
Marine Mammal Research and Conservation Network of India, 2020. Http://Www.Marinemammals.in/Database/Sightings-and-
Strandings/. Retrieved August 5, 2020, from www.marinemammals.in/database
Mikhalev, Y.A. 2000. Whaling in the Arabian Sea by the whaling fleets Slava and Sovetskaya Ukraina. Pp.141–81. In: Yablokov,
A.V., Zemsky, V.A. and Tormosov, D.D. (eds). Soviet Whaling Data, (1949–1979). Centre for Russian Environmental Policy,
Moscow, 408pp.
Mintzer, V. J., Diniz, K. and Frazer, T.K. 2018. The use of aquatic mammals for bait in global fisheries. Frontiers in Marine
Science, 5:191: 1–26.
MoEFCC, 2021. Marine mega fauna stranding management guidelines. Ministry of Environment, Forest and Climate Change,
Govt. of Kerala, 27pp.
Monalisha, S. and Patterson, E.J.K. 2014. Record on Indo pacific male finless porpoise, Neophocaena phocaenoides (G. Cuvier,
1829) stranded along Vadrevu port, Andhra Pradesh coast, India. Indian Journal of Geo-Marine Sciences, 43: 2281-2288.
Muralidharan, R. 2018. Entangled lives of dolphins and fishers. Seminar (Vol. 702, pp. 62-65); https://goo.gl/xJ3hdd
Journal of Aquatic Biology & Fisheries 11
Biju Kumar et al.
Nameer, P.O. 2016. Checklist of marine mammals of Kerala - a reply to Kumarran (2016) and the updated checklist of marine
mammals of Kerala. Journal of Threatened Taxa 8(1): 8417–8420; http://dx.doi.org/10.11609/jott.2497.8.1.8417-8420
New, L.F., Hall, A.J., Harcourt, R., Kaufman, G., Parsons, E.C.M., Pearson, H.C., MelCosentino, A. and Schick, R.S. 2015. The
modelling and assessment of whale-watching impacts. Ocean and Coastal Management, 115: 10–16.
Ozturk, B., Ozturk, A.A. and Dede, A. 2001. Dolphin by-catch in the swordfish driftnet fishery in the Aegean Sea. Rapp.; Comm.
Int. Medit., 36: 308.
Peltier, H., Baagoe, H. J., Camphuysen, C., Czeck, R., Dabin, W., Daniel, P., Deaville, R., Haelters, J., Jauniaux, T., Jensen, L.,
Jepson, P., Keijl, G., Siebert, U., Canneyt, O. and Ridoux, V. 2013. The stranding anomaly as population indicator: the case of
Harbour Porpoise Phocoena phocoena in North-western Europe. Plos One. e62180: 1-14; 10.1371/annotation/1ce2f54e-1eea-
4dba-8742-05db1017b44f.
Perrin, W. F. and Geraci, R. 2002. Stranding. In Perrin, W. F., Wursig, B. and Thewissen., J. G. M. (Eds.), pp. 1192–1197.
Encyclopedia of Marine Mammals, San Diego, CA: Academic Press.
Perrin, W.F., Wursig, B. and Thewissen, J.G.M. 2009. Encyclopedia of Marine Mammals. San Diego, CA: Academic Press,
1352pp.
Porter, L. and Lai, Y.H. 2017. Marine Mammals in Asian Societies; Trends in Consumption, Bait, and Traditional Use. Frontiers
in Marine Science, 28; https://doi.org/10.3389/fmars.2017.00047
Reeves, R. R., McClellan, K. and Werner, T. B. 2013. Marine mammal bycatch in gillnet and other entangling net fisheries, 1990
to 2011. Endangered Species Research, 20: 71–97.
Roman, J., Estes, J. A., Morissette, L., Smith, C., Costa, D., McCarthy, J., Nation, J.B., Nicol, S., Pershing, A. and Smetacek, V.
2014.Whalesas marine ecosystem engineers. Frontiers in Ecology and the Environment, 12(7): 377–385.
Simmonds, M. P. 2012. Cetaceans and marine debris: The Great unknown. Journal of Marine Biology, 684279; doi:10.1155/2012/
684279
Sutaria, D. 2018. Baleen whale reports from the eastern Arabian Sea based on interview surveys and stranding reports - update
from India. SC/67A/CMP/03_Rev, Bled, Slovenia.
Sutaria, D. 2019. A Report on Baleen Whale Records and Recent Developments in Marine Dolphin Conservation; 10.13140/
RG.2.2.12437.17128.
Sutaria, D., Sule, M., Jog, K., Bopardikar, I., Jamalabad, A. and Panicker, D. 2016. Baleen whale records from the Arabian Sea,
India from June 2015 To May 2016. SC/66b/SH/34.
Sutaria, D., Sule, M., Jog, K., Bopardikar, I., Jamalabad, A. and Panicker, D. 2017. Baleen Whale Records from India. SC/67A/
CMP/03_Rev, Bled, Slovenia.
Trianni, M. S. and Tenorio, M. C. 2012. Summary of recorded cetacean strandings in the Commonwealth of the Northern Mariana
Islands. Micronesica, 43(1): 1 – 13.
Van Waerebeek, K., Baker, A.N., Folix, F., Gedamke, J., Iniguez, M., Sanino, G.P., Secchi, E., Sutaria, D., van Helden, A. and
Wang, Y. 2007. Vessel collision with small cetaceans worldwide and with large whales in the southern Hemisphere, an initial
assessment. Latin American Journal of Aquatic Mammals, 6: 43–69.
Vivekanandan, E. and Jeyabaskaran. R. 2012. Marine Mammal Species of India. Central Marine Fisheries Research Institute,
Kochi, 228p.
Walker, R., Keith, E., Yankovsky, A. and Odell, D. 2005. Environmental correlates of cetacean mass stranding sites in Florida.
Marine Mammal Science, 21. 327-335; 10.1111/j.1748-7692.2005.tb01233.x.
Williams, O. 2018. Biological and Abiotic Factors Influencing Cetacean Mass Strandings in the Northeastern United States.
Capstone. Nova Southeastern University. Retrieved from NSU Works. (336)
Yousuf, K.S.S.M., Anoop, A.K., Anoop, B., Afsal, V.V., Vivekanandan, E., Kumarran, R.P., Rajagopalan, M., Krishnakumar,
P.K. and Jayasankar, P. 2009. Observations on the incidental catch of cetaceans in three landing centres along the Indian coast.
Marine Biodiversity Records, 2(e64): 1-6.
Zhao, L., Zhu, Q., Miao, X., Xu, M., Wu, F., Dai, Y., Tao, C., Mou, J. and Wang, C. 2017. An overview of cetacean strandings,
bycatches and rescues along the western coast of the Taiwan Strait, China: 2010–2015. Acta Oceanologica Sinica, 36(12):31–
6; https://doi.org/10.1007/s13131-017-1100-5
