Conference PaperPDF Available

An update on the catch composition and other aspects of cetacean exploitation in Ghana

Authors:

Abstract and Figures

Photographs of 231 landed specimens (212 identifiable) were analysed to determine species composition of cetacean take in Ghana's artisanal fisheries in 1995-2010, the most comprehensive sample documented in West Africa. The three most commonly landed species are: 24.5% Clymene dolphin (Stenella clymene), 13.2% pantropical spotted dolphin (Stenella attenuata), 12.3% common bottlenose dolphin (Tursiops truncatus). Also regularly caught are: 10.4% melon-headed whale (Peponocephala electra), 9.4% short-finned pilot whale (Globicephala macrorhynchus), 9.4% long-beaked common dolphin (Delphinus capensis). Occasionally landed are: 6.1% rough-toothed dolphin (Steno bredanensis), 4.7% Risso's dolphin (Grampus griseus), 3.1% kogiids (including Kogia sima) and 2.8% spinner dolphin (Stenella longirostris). Rarely (<2%) landed are: Atlantic spotted dolphin (Stenella frontalis), Fraser's dolphin (Lagenodelphis hosei), false killer whale (Pseudorca crassidens) and pygmy killer whale (Feresa attenuata). One small sperm whale was recorded taken offshore. Catch rate estimators, cetaceans landed per month (cpm) and cetaceans landed per day (cpd) were derived for 3 ports, but the national situation is unknown. At Axim, in 23 months, 130 cetaceans were observed landed (mean 5.65 ±SE 1.19 cpm); prorated per annum, 67.8 ±SE 14.28. During high-intensity surveying Jan-Nov 2003, 52 cetaceans were recorded in 192 days, with mean daily landings 0.271 cpd, prorated per annum 99.0. Reported landings at Axim in Aug-Dec 2007 were limited (0.087 cpd), prorated per annum 31.8 cetaceans, however a negative sampling bias was indicated making this cpd questionable. At Apam in 1995-99 mean monthly landings were a very low 1.117 (±SE 0.23 cpm); prorated per annum 13.40 (±SE 2.76) cetaceans. In Oct 2001-Oct 2003, 128 cetaceans were observed, ie mean monthly landings 5.57 ±SE 1.29 cpm (n= 23, range 1-25), prorated per annum 66.84 (±SE 15.48). Intensive surveying in Jan-Nov 2003 saw 87 cetaceans landed on 267days, or 0.362 cpd; prorated per annum 132.22. The cpm in 2001-03 increased very significantly compared to 1995-99. Highest catches occurred at Dixcove: in 25 months (Oct 2001-Oct 2003) 564 cetaceans were observed, mean monthly landings 22.56 ±SE 3.26 cpm (n=25, range 6-69), prorated per annum 270.72 ±SE 39.12 cetaceans. Mean daily landings rate 0.74 cpd. In 2009-10, daily landings became the norm with frequent multiple landings; highest one-day catch >20 dolphins. In April 2010, of 9 cetaceans landed in 7 days, 3 were butchered before a team could document them, supporting caveat that observed landings underestimate true landings. An intensive biological sampling programme and nation-wide recording of cetacean captures are needed immediately, to guide the formulation and implementation of effective management and conservation measures.
Content may be subject to copyright.
Scientific Committee Meeting, Agadir, Morocco, June 2010 SC/62/SM10
An update on the catch composition and other aspects
of cetacean exploitation in Ghana
Joseph S. Debrah1, Patrick K. Ofori-Danson2 and Koen Van Waerebeek 3,4
1 Fisheries Biology Lecturer, Dept.of Fisheries and Aquatic Sciences, University of Cape Coast, Cape Coast, Ghana
2 Senior Lecturer, Department of Oceanography and Fisheries, P.O. Box LG99, University of Ghana, Legon, Ghana
3 Conservation and Research of West African Aquatic Mammals (COREWAM-Ghana), P.O. Box LG99, EcoLab,
University of Ghana, Legon, Ghana
4 Centro Peruano de Estudios Cetológicos (CEPEC), Museo de Delfines, Pucusana, Peru.
ABSTRACT
Photographs of 231 landed specimens (212 identifiable) were analysed to determine species composition of cetacean take in
Ghana's artisanal fisheries in 1995-2010, the most comprehensive sample documented in West Africa. The three most commonly
landed species are: 24.5% Clymene dolphin (Stenella clymene), 13.2% pantropical spotted dolphin (Stenella attenuata), 12.3%
common bottlenose dolphin (Tursiops truncatus). Also regularly caught are: 10.4% melon-headed whale (Peponocephala
electra), 9.4% short-finned pilot whale (Globicephala macrorhynchus), 9.4% long-beaked common dolphin (Delphinus capensis).
Occasionally landed are: 6.1% rough-toothed dolphin (Steno bredanensis), 4.7% Risso's dolphin (Grampus griseus), 3.1% kogiids
(including Kogia sima) and 2.8% spinner dolphin (Stenella longirostris). Rarely (<2%) landed are: Atlantic spotted dolphin
(Stenella frontalis), Fraser's dolphin (Lagenodelphis hosei), false killer whale (Pseudorca crassidens) and pygmy killer whale
(Feresa attenuata). One small sperm whale was recorded taken offshore.
Catch rate estimators, cetaceans landed per month (cpm) and cetaceans landed per day (cpd) were derived for 3 ports, but the
national situation is unknown. At Axim, in 23 months, 130 cetaceans were observed landed (mean 5.65 ±SE 1.19 cpm); prorated
per annum, 67.8 ±SE 14.28. During high-intensity surveying Jan-Nov 2003, 52 cetaceans were recorded in 192 days, with mean
daily landings 0.271 cpd, prorated per annum 99.0. Reported landings at Axim in Aug-Dec 2007 were limited (0.087 cpd),
prorated per annum 31.8 cetaceans, however a negative sampling bias was indicated making this cpd questionable. At Apam in
1995-99 mean monthly landings were a very low 1.117 ( ±SE 0.23 cpm); prorated per annum 13.40 (±SE 2.76) cetaceans. In Oct
2001-Oct 2003, 128 cetaceans were observed, ie mean monthly landings 5.57 ±SE 1.29 cpm (n= 23, range 1-25), prorated per
annum 66.84 (±SE 15.48). Intensive surveying in Jan-Nov 2003 saw 87 cetaceans landed on 267days, or 0.362 cpd; prorated per
annum 132.22. The cpm in 2001-03 increased very significantly compared to 1995-99. Highest catches occurred at Dixcove: in 25
months (Oct 2001-Oct 2003) 564 cetaceans were observed, mean monthly landings 22.56 ±SE 3.26 cpm (n=25, range 6-69),
prorated per annum 270.72 ±SE 39.12 cetaceans. Mean daily landings rate 0.74 cpd. In 2009-10, daily landings became the norm
with frequent multiple landings; highest one-day catch >20 dolphins. In April 2010, of 9 cetaceans landed in 7 days, 3 were
butchered before a team could document them, supporting caveat that observed landings underestimate true landings. An intensive
biological sampling programme and nation-wide recording of cetacean captures are needed immediately, to guide the formulation
and implementation of effective management and conservation measures.
KEYWORDS: SMALL CETACEANS; LANDINGS; CATCH RATES; PORT MONITORING; GULF OF GUINEA
INTRODUCTION
In comparison with the low to moderate levels of information available on cetacean-fisheries interactions for some
areas off northwest Africa (e.g. Maigret, 1994; Van Waerebeek et al., 2000, 2003; Zeeberg et al., 2006; Bamy et al.,
2010) and southwest Africa (e.g. Best and Ross, 1977; Findlay et al., 1992; Peddemors, 1999; Peddemors et al.,
1997), the little what is known for the Gulf of Guinea1 largely relates to incidental observations (Van Waerebeek and
De Smet, 1996; Van Waerebeek et al., 2004; Uwagbae and Van Waerebeek, 2010; Segniagbeto and Van Waerebeek,
2010) with the exception of Ghana where small cetacean captures have been documented periodically, albeit on a
limited scale, since 1995 (Ofori-Danson and Agbogah, 1995; Ofori-Danson and Odei, 1997; Van Waerebeek and
Ofori-Danson, 1999; Debrah, 2001; Ofori-Danson et al., 2003; Van Waerebeek et al., 2009; this paper). Until 2000,
8 species (Debrah, 2000) were known to be taken in Ghana's artisanal fisheries, then updated to 14 and 15 species
(Ofori-Danson et al., 2003; Van Waerebeek et al., 2009). The first approximation of the species catch composition
was derived from a relatively limited sample of 58 specimens examined in a 3-year period (1998-2000). Species
were very unequally exploited, with three of them, Clymene dolphin Stenella clymene, pantropical spotted dolphin
Stenella attenuata and common bottlenose dolphin Tursiops truncatus, representing 67.2% of all landings, while
other species were much less commonly or even rarely taken (Ofori-Danson et al., 2003). This paper covers a partial
1 definition as by the International Hydrographic Organization (1953)
1
analysis of aspects of Ghana port monitoring since 1995, in particular it provides a significantly improved estimate of
the relative catch composition as well as explores apparent trends in cetacean catches. This preliminary evaluation
should at least allow managers to focus on the most affected species and help define and implement appropriate
management measures.
MATERIAL AND METHODS
As in many other maritime nations, no national scheme for the systematical data recording of cetacean landings is
operating in Ghana. This may partly be a matter of limited resources, but it is also an awareness issue because
captured cetaceans are still too often considered, equivocally, to constitute an unwanted by-catch, instead of a fully
utilised marine living resource that begs proper management. Partial and periodical port surveying has, so far, mostly
been co-ordinated by fisheries science academics (Universities of Ghana and Cape Coast) concerned with the
scarcity of data despite high mortality levels.
In the field, cetacean landings were recorded (voluntarily) by fisheries officers or by one of the authors. Most
information originates from the Western Region, mainly from three artisanal ports known for their regular catches,
i.e. Dixcove (04°48'N,01°57'W), Apam (05°17'N,00°44'W) and Axim (04°51.3’N, 02°13.5’W). Numbers (without
species data) landed at Apam in 1995-1997 are from Ofori-Adu (1998); 1998-99 data are from Debrah (2000). A
survey period with optimal coverage stretched between October 2001 and October 2003.
Species composition was determined from a 15yr (1994-2010) pooled sample of photographed specimens
(N=231, of which Npos =212 positively identified). Photographic evidence is archived both at EcoLab, University of
Ghana and at CEPEC. Estimators for relative capture rates were defined as cetaceans landed per month (cpm) and
cetaceans landed per diem (cpd), the latter for periods with intensive (daily) surveying and reporting. Annual
estimates are provided prorated from either cpm or cpd (365.24 days per annum-base) and, in the latter case, some
limited bias from lack of stratification is acknowledged. However, we believe such bias would be negligible
compared to the existing negative sampling bias from cetaceans landed but not reported/tallied.
Fisheries officers with an intimate knowledge of the local fishers communities agreed to count, and if time
allowed, document, any cetaceans on the landing beaches during their customary controls of fishing activities.
Periods of low or no effort alternated with periods of higher effort, depending on project activity/funding, the
presence of biologists in the field, as well as the officers' personal interest. Data requested comprised: observer
name, port, date, fishing gear (drift gillnet or purse-seine), daily fishing effort (number of boats landing), standard
body length (SL), tooth counts and photographs. Due to understaffing, officers could not supervise the totality of
landing operations that often occur simultaneously at different landing beaches of a port. An indeterminate number
of landed animals are not observed. In addition, not all carcasses are landed as an unassessed percentage are used
offshore for shark bait (Debrah, 2000). Our statistics reflect minimum values for actual removals.
Observers were asked to daily note entries including on off-effort days and days without cetaceans. Authors regularly
visited stations, collected notes, replaced equipment and serviced stipendia. Compact cameras plus film, and in the
later stages, digital cameras, were provided. Print photographs were digitized. Originally we attempted to use species
identifications by observers but this was abandoned when cross-checks showed such IDs to be unreliable. All
specimens were re-assessed and identified by at least two of the authors (including KVW), exclusively based on
photographs. If unclear, they were assigned to 'unidentified small cetacean'. Recently skin samples were collected
opportunistically. Dolphin heads were acquired and deposited in a cranial reference collection at the University of
Ghana, but much larger samples of both skulls and tissues will be needed for in-depth population studies.
RESULTS
Nation-wide cetacean takes
Video evidence recorded from a drilling platform in Ghana's Jubilee Field shows an apparently deliberate capture of
a small sperm whale Physeter macrocephalus by the crew of a large canoe. This adds the sperm whale as 16th to the
current list of 15 species documented taken in artisanal fisheries, the great majority in drift gillnets and a few in set
gillnets and purse-seines (Van Waerebeek and Ofori-Danson, 1999; Debrah, 2000; Ofori-Danson et al., 2003; Van
Waerebeek et al., 2009). The catch composition is shown in Table 1. The three most commonly landed cetaceans are:
24.5% Clymene dolphin (Stenella clymene), 13.2% pantropical spotted dolphin (Stenella attenuata) and 12.3%
common bottlenose dolphin (Tursiops truncatus). Also regularly landed are: 10.4% melon-headed whale
(Peponocephala electra), 9.4% short-finned pilot whale (Globicephala macrorhynchus), 9.4% long-beaked common
dolphin (Delphinus capensis). Occasionally captured are: 6.1% rough-toothed dolphin (Steno bredanensis), 4.7%
Risso's dolphin (Grampus griseus), 3.1% kogiids (including Kogia sima) and 2.8% spinner dolphin (Stenella
longirostris). The species that are rarely landed (<2%) include: Atlantic spotted dolphin (Stenella frontalis), Fraser's
dolphin (Lagenodelphis hosei), false killer whale (Pseudorca crassidens) and pygmy killer whale (Feresa attenuata).
Most cetaceans were netted in wide-mesh drift gillnets which target primarily large pelagic vertebrates, mainly
skipjack tuna (Katsuwomis pelamis), yellowfin tuna (Thunnus albacares), sailfish (Istiophorus platypterus), blue
marlin (Makaira nigricans), swordfish (Xiphias gladius), dolphin fish (Coryphaena hippurus), wahoo
(Acanthocybium solanderi), barracuda (Sphyraena sp.), manta ray (Manta birostris), blue shark (Prionace glauca),
and some mustelid sharks. Commercialization of cetaceans and, to a lesser degree, of several species of sea turtles
2
(Cheloniidae), for food contribute to the economic viability of the gillnet fishery. Cetaceans, originally by-catches,
have now become secondary target species. Most cetaceans are landed freshly dead following entanglement, but
occasionally if animals are alive when retrieved they are killed, with piercing lance-like metals, cutlasses, hand-
harpoons or sticks (Debrah, 2000), further supporting the intentional nature of the exploitation. Both landing and
utilization of small cetaceans occurs overtly and is socially accepted. However, in the cities, indications are that most
Ghanaians are even unaware of the presence of dolphins in their waters. In the Volta Delta region, traditional taboos
against catching dolphins, for instance among the Ewe people, are fast eroding. It is unknown to what extent, and
how precisely, cetaceans are used as bait in shark fisheries. Strong demand and high prices for shark fins as an export
product to Asian markets constitute a powerful incentive to boost shark fisheries. However prices for cetaceans have
steadily increased and, in 2010, roughly equal these for similarly-sized, large billfishes.
Axim
Observed monthly landings for a 23 month period (between Oct 2001-Oct 2003, Table 2) indicate a total of 130
small cetaceans reported landed at the Axim fishing port (mean cpm=5.65 ±SE 1.19, median 4, range 0-20. prorated
per annum, 67.8 ±SE 14.28). However, the most intensive and accurate monitoring effort in Axim occurred in the
period January-November 2003 when 52 cetaceans were recorded landed in 192 days, or a mean daily landings rate
of 0.271 cpd. Prorated per annum gives a 99.0 estimate. Reported landings in August-December 2007 (Table 3) were
much reduced, with a mean daily landings rate of 0.087 cpd (prorated per annum: 31.8 cetaceans). However,
indications were that some observers spent considerably less time surveying landing beaches even while marking
'on-effort' days and a significant number of cetaceans may have been missed, leading to an underestimate.
Monitoring in Axim was interrupted.
Apam
Reported cetacean landings at Apam before 2000 were: in 1995 (n=12), 1996 (n=18), 1997 (n=18), 1998 (n=12),
1999 (n=7), with a monthly mean landings rate of 1.117cpm (±SE 0.23cpm) and no significant variation between
years (Kruskal-Wallis, 4.51, df 4, p=0.341). Prorated gives a per annum mean of 13.40 (±SE 2.76) landed cetaceans
for the 1995-99 period.
Monthly landings at Apam recorded over 23 months (between October 2001-October 2003) are shown in
Table 2. At least 128 small cetaceans were landed in that period, with mean monthly landings of 5.57 cpm ±SE 1.29
(n= 23, median 4, range 1-25); which prorated gives a per annum mean of 66.84 (±SE 15.48) landed cetaceans.
The most detailed record keeping occurred in January-November 2003 when 87 small cetaceans were reported
landed on 267 monitoring days, or a daily landings rate of 0.362 cpd, twice as high as the estimated cpd (0.183) for
the less intensily surveyed 23months; prorated per annum estimate is 132.22 cetaceans. The cpm in the period 2001-
03 increased very significantly compared to 1995-99 (Mann-Whitney U= 325.5; p<0.0001).
Dixcove
The highest catches have been reported consistently from Dixcove. Monthly landings recorded over 25 months
(between October 2001-October 2003) show a total of 564 small cetaceans observed landed (Table 2). Mean monthly
landings of 22.56 ±SE 3.26 cpm (n=25, median 17, range 6-69) prorated to per annum estimate is 270.72 ±SE 39.12
cetaceans landed. The mean daily landings rate was 0.74 cpd. During the intensive monitoring period of January-
November 2003, 174 cetaceans were reported over 241 days (0.722 cpd), practically the same cpd value as for the 2-
year period. More recently, in 2009-10, while detailed statistics were not available for this report, daily landings have
become the norm, with multiple landings per day common. The highest one-day catch observed exceeded 20
specimens (senior officer Amiah Johnson, pers.comm. to KVW, 22 April 2010). In 7 days (17-23 April 2010) of
survey effort at Dixcove, we recorded 9 cetaceans: 3 S. bredanensis, 2 T. truncatus, 1 juvenile G. macrorhynchus,
and 3 unidentified dolphins sold and butchered before we could reach the landing spot, confirming the thesis that
observed landings underestimate true landings.
During 2001-2003, the combined landings at the three studied ports show seasonal peaks in landings during
the periods November-January (Figure 1), the reason of which is unclear.
Other ports
A few landings opportunistically recorded during brief visits of other ports (Table 1) cannot reflect the extent of
captures there (e.g. 2 T. truncatus at Jamestown/1994, 1 S. clymene at Winneba/1998; 1 S. clymene at Ada-Foah/
2003), however these serve to remind us that cetacean catches are not limited to the habitually monitored ports.
Eventually all Ghanaian ports will need to be surveyed systematically.
DISCUSSION
Catch statistics
No estimates of total cetacean landings in Ghana are available, as (incomplete) data exist only for three ports. An
estimated 99 cetaceans were landed at Axim in 2003. The 2007 estimate of 32 animals was thought to be greatly
underestimated due to poor effort compliance leading to landed animals being missed. At Apam, mean annual
3
landings for the earliest recording period 1995-99 were estimated at a mere 13.4 cetaceans. This figure increased
tenfold to an estimated 133 cetaceans landed in 2003. Highest catches were seen at Dixcove, with a mean of 270
cetaceans landed per annum in the years 2001-03. Although raw data of most recent years have not yet been
analysed, indications are that numbers have sharply increased, daily or even multiple landings have become the norm
at Dixcove, and its yearly catches most probably now amount to the higher hundreds, especially taking into account
the bias caused by missed landings. Inevitable takes at Tema, Jamestown, Shama, Half-Assini, Winneba, Ada, Kpone
and other, smaller, fishing communities remain unassessed, but some of these could also be significant. Finally,
bycatches and potential landings by the large-scale, industrial fisheries (e.g. at Tema), including offshore tuna purse-
seining, have not been monitored.
Affected species
Small cetaceans are recorded harvested along the Ghanaian coast since at least 1994, but some earlier reports go back
to 1956 (Van Waerebeek et al., 2009). Over 97% of cetaceans caught are Delphinidae, the exceptions include a few
kogiids (only K. sima confirmed) and a single ziphiid. A quarter of catches (24.5%) affected S. clymene, with
indications that the species is less commonly landed recently. The high take prompted CMS to include the West
African population of S. clymene on Appendix II in 2008. Second and third most exploited species are, as found
before (Ofori-Danson et al., 2003), respectively, S. attenuata and T. truncatus. The latter includes offshore stock
individuals (from fishery data) but inshore stock individuals may also be involved. The species that rarely showed up
in our sample may either be that, rarely exploited and under no particular threat, or be remnants of once common
species in Ghana's waters. The rare appearance of spinner dolphins and Atlantic spotted dolphins are, at least,
unexpected. A single killer whale Orcinus orca museum record was recognised as possibly derived from a by-catch
but no captures are confirmed. Among ziphiids, a single Cuvier's beaked whale was recorded (Ofori-Danson et al.,
2003; Van Waerebeek et al., 2009). The Atlantic humpback dolphin Sousa teuszii has been consistently absent from
records since port surveillance started (Ofori-Danson et al., 2003; Van Waerebeek et al., 2003, 2009). A historic
population collapse due to by-catches predating monitoring has been suggested (Van Waerebeek et al., 2004). The
species' preference for shallow, nearshore and estuarine habitat would render it particularly vulnerable to ubiquitous
inshore set gillnets, beach seines and other anthropogenic disturbances. Alternatively, a natural distribution gap may
exist off Ghana/Togo related to periodical cool upwelling. Interviews with local residents in the Volta Delta
concorded in that inshore-dwelling dolphins have become scarce, and -from behavioural clues- may be bottlenose
dolphins. Evidence from Benin and Brass Island, Niger Delta, shows that inshore bottlenose dolphins are present in
the Bight of Benin (Uwagbae and Van Waerebeek, 2010).
Variation between ports
About 74% of all recorded catches have originated from Dixcove (Table 2) where a large community of drift gillnet
fishers is based. However, the port has also received most attention, has been monitored for longer periods, and its
fisheries officer (A. Johnson) has been exceptionally proactive. Lower numbers recorded at Apam are attributable to
less intense survey effort, the west-ward migration of gillnet fishers and a greater distance from the port to the
continental slope (translating in fewer trips) where many cetaceans forage. Axim harbours a proportionally bigger
share of purse-seiners which target small schooling fishes and which infrequently take cetaceans. Landings at Axim
are thought to be underestimated due to a negative sampling bias.
Trends and the utilization of cetaceans
While no quantifiable data exist to evaluate the extent cetaceans are used as bait in shark fisheries, most captured
animals seem to be landed, butchered on land and sold for human consumption. Salted, smoked or dried, processed
cetacean products are 'exported' mainly to the hinterland. Exploitation acquired a commercial character with the
increase in demand. Currently prices for dolphins are as high as those for similarly-sized billfishes such as sailfish
and marlin. In contrast with neighbouring countries Togo (see Segniagbeto and Van Waerebeek, 2010) and Côte
d'Ivoire (A. Johnson, pers.comm. to KVW, April 2010) where the overt landing of cetaceans is not permitted, at
Ghana ports cetaceans are landed and sold without impediment. This offers the undeniable advantage of allowing
catch statistics, the study of trends and provides opportunities for biological studies based on carcass sampling
protocols (e.g. morphological variation, growth and reproduction, feeding ecology, stock identification, genetics,
parasitology, contaminant loads, and pathology).
Brashares et al. (2004) found that fish supply was related negatively to the volume of bushmeat of 41 large
mammal species sold in local markets in Ghana. The growing commercialization of small cetacean products for
human consumption 1995-2009 has occurred after a gradual decline in Ghana of the per capita fish supply since 1975
(Armah et al., 1996; Brashares et al., 2004) and a decline in reported total catches of aquatic organisms since 1999
(UNEP, 2006). This causal relationship was frequently cited by interviewed fishermen to explain their increasing
captures of dolphins and sea turtles. This was predicted with the definition of the term 'marine bushmeat' (Alfaro-
Shigueto and Van Waerebeek, 2001; Clapham and Van Waerebeek, 2007). It does not bode well for the future, as the
potential exists for a run-away process where annual dolphin catches could rise from the high hundreds into the
thousands, with the danger of a collapse in one or more populations, if fish stocks in the region deplete even further.
4
Status and management issues
The status of exploited species cannot presently be evaluated, as no population estimates for the Gulf of Guinea, nor
estimates of total removals are available. The minimum landings at three fishing ports however are sufficiently high
to express concern about the sustainability of current, and foreseeable increasing, levels of exploitation of S.
clymene, S. attenuata and T. truncatus.
While aquatic mammals are among the first schedule of Ghana's 1971 Wildlife Conservation Regulations (LI. 685),
and are protected by law, there are no explicit instructions concerning the use of cetaceans killed in nets. Banning
cetacean landings might appear an obvious necessity, however such a measure must be carefully evaluated in the
light of local context as, by itself, it would not guarantee an effective protection for cetacean populations.
Enforcement of a ban must be both feasible and acceptable by coastal communities. Furthermore, by-catch is largely
inevitable as long as gillnets are deployed and will continue to produce dolphin deaths. Also, covert landings may
become established and illegal trade (black market) may not be avoidable. If in addition alternative uses for cetacean
products are created or strengthen (e.g. use as bait), then cetacean catches may remain as high as in a pre-ban
environment, as demonstrated in Peru (Van Waerebeek and Reyes, 1994; Mangel et al., 2010).
To stimulate research and public awareness of aquatic mammals in Ghana and enhance regional collaboration the
ngo COREWAM-Ghana (Conservation and Research of West African Aquatic Mammals) was set up.
Further recommended actions include:
- The tallying of cetacean landings be implemented as a standard procedure for fisheries observers at the national
level, recognizing that small cetaceans are a de facto exploited marine living resource and therefore need to be
monitored on a permanent basis.
- Greatly improve information flow to Ghanaian citizens and initiate an informed national debate on the issue of
cetacean exploitation. Although cetaceans enjoy some legal protection there is no functional, long-term strategy to
effectively manage populations.
- Implement an intensive biological sampling programme based on fresh carcasses, collecting data on morphological
variation, reproduction, growth, feeding, stock identification, genetics, migratory habits, etc. Utilize platforms of
opportunity for information on distribution, relative abundance and behaviour.
- Training and support of field personnel of Fisheries and Wildlife divisions.
ACKNOWLEDGEMENTS
Fisheries observers at Dixcove, Apam and Axim are thanked for their essential contributions. Without A. Johnson's
enthusiastic collaboration, work at Dixcove would not have been nearly as successful. Over the years, financial
support was provided by various institutions, mainly CMS/UNEP (WAFCET-3 Project), IFAW, WDCS and Leopold
III Fund for Nature Research and Exploration. Additional support was granted by Colombus Zoological Park
Association, Chicago Zoological Society, and Varda Group.
REFERENCES
Alfaro-Shigueto, J. and Van Waerebeek, K. 2001. Drowning in the sea of silence: the bushmeat concept applied for marine fauna.
Zoos and Aquariums committing to Conservation, symposium hosted by Brevard Zoo, 28 Nov.–2 Dec. 2001, Orlando, Florida
(published abstract).
Armah, A.K., Darpaah, G.A. and Wiafe, G. 1996. Managing the coast of Ghana: problems and options. In: The coastal zone of
Africa: problems and management. S.M. Evans, C.J. Vanderpuye and A.K. Armah (ed.). Penshaw Press. 246pp.
Bamy, I.L., Van Waerebeek, K., Bah, S.S., Dia, M., Kaba, B., Keita, N. and Konate, S. 2010. Species occurrence of cetaceans in
Guinea, including humpback whales with southern hemisphere seasonality. Marine Diversity Records 3 (e48): 1-10.
doi:10.1017/S1755267210000436
Best, P.B. and Ross, G.J.B. 1977. Exploitation of small cetaceans off southern Africa. Rep. Int.Whal. Commn. 27: 494-7.
Brashares, J.S., Arcese, P., Sam, M.K., Coppolillo, P.B., Sinclair, A.R.E. and Balmford, A. 2004. Bushmeat hunting, wildlife
declines, and fish supply in West Africa. Science 306: 1180-1183.
Clapham, P. and Van Waerebeek, K. 2007. Bushmeat, the sum of the parts. Molecular Ecology 16: 2607-2609.
Debrah, J.S. 2000. Taxonomy, exploitation and conservation of dolphins in the marine waters of Ghana. Master of Philosophy
thesis, Department of Oceanography and Fisheries, University of Ghana. 86pp.
Findlay, K., Best, P.B., Ross, G.J.B. and Cockcroft. 1992. The distribution of small odontocete cetaceans off the coast of South
Africa and Namibia. S. Afr. J. mar Sci. 12: 237-70.
International Hydrographic Organization. 1953. Limits of Oceans and Seas. Special Publication N° 28. Imprimérie Monégasque,
Monte-Carlo, Monaco.
Maigret, J. 1994. Marine mammals and fisheries along the West African coast. Rep.Int.Whal. Commn. (special issue 15): 307-
316.
Mangel, J.C., Alfaro-Shigueto, J., Van Waerebeek, K., Cáceres, C., Bearhop, S., Witt, M.J., Godley, B.J. 2010 Small cetacean
captures in Peruvian artisanal fisheries: High despite protective legislation. Biological Conservation 143: 136-143.
Ofori-Danson P. K. and Agbogah K. 1995. Survey of aquatic mammals of Ghana. A report presented to the Oceans and Coastal
Areas, Programme Activity Centre (OCA/PAC) of the United Nations Environment Programme. Institute of Aquatic Research,
Tech. Rep. 143.
Ofori-Danson P. K. and Odei M. A. 1997. Preliminary observations of the common dolphin, Delphinus delphis, (Order: Cetacea;
fam: Delphinidae) in the Ghanaian coastal waters. IWC Scientific Committee Document SC/49/SM3, Bournemouth, UK.
5
Ofori-Adu, D.W. 1998. Status of small cetaceans in Ghana coastal waters. Mimeograph, Tema Fisheries Research Unit, Tema,
Ghana. 19pp. (unpublished).
Ofori-Danson, P.K., Van Waerebeek, K. & Debrah, S. 2003. A survey for the conservation of dolphins in Ghanaian coastal
waters. Journal of the Ghana Science Association 5(2): 45-54.
Peddemors, V. 1999. Delphinids of Southern Africa: a review of their distribution, status and life history. J. Cetacean Res.
Manage. 1(2): 157-165.
Peddemors, V. M., Cockcroft, V.G. and Best, P.B. 1997. Exploitation of small cetaceans off South Africa: 1978-1996. IWC
Scientific Committee document SC/49/SM34, Bournemouth, Sept 1997 (unpublished). 13pp.
Segniagbeto, G. and Van Waerebeek, K. (2010). A first note on the status of cetaceans in Togo. IWC Scientific Committee
document SC/62/SM11, Agadir, Morocco.
United Nations Environment Programme (UNEP). 2006. Africa Environment Outlook 2. Available from
http://www.unep.org/dewa/africa/aeo2_launch.
Uwagbae, M. and Van Waerebeek, K. 2010. Initial evidence of dolphin takes in the Niger Delta region and a review of Nigerian
cetaceans. IWC Scientific Committee document SC/62/SM1. 8pp.
Van Waerebeek, K. and Reyes, J.C. 1994. Post-ban small cetacean takes off Peru: a review. Reports of the International Whaling
Commission (Special Issue 15): 503-520.
Van Waerebeek, K. and De Smet, W.M.A. 1996. A second record of the false killer whale Pseudorca crassidens (Owen, 1846)
(Cetacea, Delphinidae) from West Africa. Mammalia 60(2): 319-322.
Van Waerebeek, K. and Ofori-Danson, P.K. 1999. A first checklist of cetaceans of Ghana, Gulf of Guinea, and a shore-based
survey of interactions with coastal fisheries. IWC Scientific Committee document SC/51/SM35. 9pp.
Van Waerebeek K., Ndiaye E., Djiba A., Diallo M., Murphy P., Jallow A., Camara A., Ndiaye P. and Tous P. 2000. A survey of
the conservation status of cetaceans in Senegal, The Gambia and Guinea-Bissau. UNEP/CMS Secretariat, Bonn, Germany.
80pp.
Van Waerebeek, K., Barnett, L., Camara, A., Cham, A., Diallo, M., Djiba, A., Jallow, A.O., Ndiaye, E., Samba Ould Bilal, A.O.
& Bamy, I. L. 2003. Conservation of Cetaceans in The Gambia and Senegal 1999-2001, and status of the Atlantic humpback
dolphin. WAFCET-2 Report. UNEP/CMS, Bonn, Germany. 55 pp.
Van Waerebeek, K., Barnett, L., Camara, A., Cham, A., Diallo, M., Djiba, A., Jallow, A.O., Ndiaye, E., Samba Ould Bilal, A.O.
and Bamy, I. L. 2004. Distribution, status and biology of the Atlantic humpback dolphin Sousa teuszii (Kükenthal, 1892).
Aquatic Mammals 30 (1): 56-83.
Zeeberg, J., Corten, A. & de Graaf, E. (2006) Bycatch and release of pelagic megafauna in industrial trawler fisheries off
Northwest Africa. Fisheries Research 78(2-3): 186-195.
Oct-
01
Nov
-01
Dec
-01
Jan
-02
Feb
-02
Mar
-02
Apr-
02
May
-02
Jun
-02
Jul-
02
Aug
-02
Sep
-02
Oct-
02
Nov
-02
Dec
-02
Jan
-03
Feb
-03
Mar
-03
Apr-
03
May
-03
Jun
-03
Jul-
03
Aug
-03
0
10
20
30
40
50
60
70
80
90
100
Seasonality in cetacean landings
AXIM
DIXCOVE
APAM
Month
number cetaceans landed
Figure 1. Seasonality in monthly landings of small cetaceans is demonstrated by the pooled samples of three Ghanaian ports
(Apam, Axim and Dixcove), as recorded by fisheries observers between October 2001 and August 2003. Peak landings occurred
from November till January.
6
Table 1. Species composition, stratified by year, of small cetacean landings at Ghana fishing ports. Numbers are subsamples of total landed cetaceans and include only specimens for
which identifiable photographs are available. The 19 specimens listed in the “unidentified” category are linked to photographs of substandard quality, some of which are under study
but most show only body parts (e.g. tail stocks) that cannot be reliably assigned to species.
Fishing portDIXCOVE AXIM APAM Ghana
1999
2000
2001
2002
2003
2005
2007
2008
2010
All yrs Dixcove
%
1994
1995
2000
undated
All yrs Axim
1998
1999
2001
2002
2003
undated
All yrs Apam
%
all years
%
Species
Tursiops truncatus 1 8 3 2 2 14 9.0 0 1 7 2 10 22.7 2 26 12.3
Grampus griseus 2 1 1 2 6 3.8 1 1 1 2 3 6.8 10 4.7
Delphinus capensis 2 3 2 7 5 19 12.2 1 1 0 0.0 20 9.4
Steno bredanensis 4 1 3 5 3.2 0 1 1 6 8 18.2 13 6.1
Lagenodelphis hosei 1 1 0.6 1 1 0 0.0 2 0.9
Stenella clymene 31 7 2 7 47 30.1 0 1 4 5 11.4 52 24.5
Stenella longirostris 4 4 2.6 1 1 0 0.0 6 2.8
Stenella attenuata 3 5 9 17 10.9 1 1 1 9 10 22.7 28 13.2
Stenella frontalis 1 1 0.6 0 0 0.0 1 0.5
Peponocephala electra 3 14 3 1 21 13.5 0 1 1 2.3 22 10.4
Feresa attenuata 1 1 0.6 0 0 0.0 1 0.5
Globicephala macrorhynchus 1 12 1 1 1 1 16 10.3 1 1 1 1 2 4.5 1 20 9.4
Pseudorca crassidens 1 1 0.6 0 3 3 6.8 4 1.9
Kogia sima 0 0.0 0 1 1 2.3 1 0.5
Kogia sp. 3 3 1.9 0 1 1 2.3 1 5 2.4
Ziphius cavirostris 0 0.0 1 1 0 0.0 1 0.5
unidentified 1 1 10 3 1 1 2
Pooled sample 156 100.0 7 44 100.0 3212 100.0
Jamestown &
Shama 1994
YEAR MONTH APAM DIXCOVE AXIM TOTAL
2001 October 0 6 4 10
2001 November 9 14 12 35
2001 December 0 24 13 37
2002 January 3 64 14 81
2002 February 4 17 1 22
2002 March 2 19 2 23
2002 April 0 24 2 26
2002 May - 19 - 19
2002 June - 17 - 17
2002 July 4 35 1 40
2002 August 7 20 0 27
2002 September 2 11 5 18
2002 October 0 14 8 22
2002 November 4 36 12 52
2002 December 6 69 12 87
2003 January 1 37 5 43
2003 February 15 7 1 8
2003 March 4 40 7 51
2003 April 3 17 1 21
2003 May 0 13 0 13
2003 June 10 9 1 20
2003 July 8 9 0 17
2003 August 5 20 1 26
2003 September 16 10 20 46
2003 October 25 13 8 46
TOTAL 128 564 130 822
% (15.6) (68.6) (15.8) (100)
Table 2. Monthly landings of small cetaceans, as recorded by fisheries observers for 23
months (Apam and Axim) or 25 months (Dixcove) in the period October 2001- October 2003
at three ports in Western Region, Ghana. Species were pooled because reliable identifications
exist only for subsamples (see Table 1).
Axim 2007 # cetaceans
landed/ # on-
effort days
Mean landings
per day
Prorated,
cetaceans landed
per month
August 4 / 17days 0.235 cpd 7.3
September 3/ 30 days 0.100 cpd 3
October 2/ 31 days 0.064 cpd 2
November 1/ 30 days 0.033 cpd 1
December 2/ 30 days 0.066 cpd 2
Total period 12/ 138 days 0.087 cpd
Table 3. Small cetaceans reported landed at Axim port in August-December 2007, as recorded
by local fisheries observers. Numbers must be interpreted as minimum numbers taken.
... The bait utilized has been primarily small cetaceans, although manatees (Trichechus senegalensis) have been targeted in Ghana (Table 1). Debrah, 2000;Ofori-Danson et al., 2003Debrah et al., 2010;Cosentino and Fisher, 2016 Greenland Agudo, 1994;Vidal et al., 1994;Romero et al., 1997Romero et al., , 2001 Stenella frontalis ...
... An absence of general cetacean research in many countries in the region may, in part, explain the scarcity of relevant source material in this review [(Elwen et al., 2011); only 13 sources (8%) provided information on bait use in African countries]. It is more likely, however, that widespread human consumption of marine mammal meat in Africa supersedes its importance as a bait in regional fisheries (Van Waerebeek et al., 2000;Andrianarivelo, 2001;Debrah et al., 2010;Robards and Reeves, 2011;Weir and Pierce, 2013;Cerchio et al., 2015). ...
... With the scarcity and high cost of protein in many locations, marine mammal meat is consumed readily and using it for bait would be difficult to justify from either a health or economic perspective. In Ghana, for example, although dolphins are used occasionally for bait, the price of cetacean meat for human consumption has equaled that of billfishes such as marlin and sailfish, so there has been little financial incentive to use the meat as bait (Debrah et al., 2010). Nevertheless, as the demand for shark fins in China continues with the growth of its middle class (Clarke et al., 2007), the financial incentives for using cetaceans as bait may increase (Debrah, 2000;Debrah et al., 2010). ...
Article
Full-text available
The use of aquatic mammals as bait to enhance the harvest of fisheries species has garnered little attention by the scientific and conservation communities, often receiving only brief mention in reports focused on the human consumption or bycatch of aquatic mammals. A number of studies, however, highlight the negative impact of this practice on affected mammal populations. A systematic review of relevant literature published since 1970 yields new insight into the scope of the issue. Findings indicate that the practice of using aquatic mammals for bait has been and continues to be geographically widespread, has affected at least 42 species, and often involves deliberate killing for the express purpose of securing bait. The nature of the fisheries involved is diverse, encompassing a wide range of target species and gear types; however, shark fisheries that employ longlines appear to be the most widely engaged in using aquatic mammals as bait. This practice appears to be most common in Latin America and Asia. It is evident, based on our review, that there is little information on the impact of the direct take on most targeted mammal populations, commonly small cetaceans, and increased monitoring efforts are needed in many locales. In most instances, the ecology and population dynamics of the targeted fishery species is poorly understood and in some cases the species is classified as threatened, suggesting a fishery sustainability issue that cannot be fully addressed with a substitute for the aquatic mammal bait. It is essential that natural resource managers implement mitigation approaches that consider the socio-economic, cultural, political, and ecological circumstances leading to the use of aquatic mammal bait in each fishery.
... Within the Gulf of Guinea [extending from Cape Palmas in Liberia to Cape Lopez in Gabon; International Hydrographic Organization (IHO), 1953], dedicated port-based research on the exploitation of cetaceans in Ghanaian waters has been carried out intermittently since 1995 using specimens and photographic evidence obtained from bycatch in fisheries, directed takes and several strandings (Ofori-Danson and Odei, 1997;Van Waerebeek and Ofori-Danson, 1999;Debrah, 2000;Ofori-Danson et al., 2003;Van Waerebeek et al., 2009Debrah et al., 2010). Recent data originating from captured specimens landed at fishing ports, as well as strandings, provided a fully validated list of 18 cetacean species for Ghana (Van Waerebeek et al., 2009). ...
... A longitudinal set of landings data on cetaceans are available from a few fishing villages in southern Ghana (Ofori-Danson et al., 2003;Debrah et al., 2010;Van Waerebeek et al., 2014; Table 3). The Dixcove village holds a large community of driftgillnet fishermen in the Ahanta district in the Western Region on Ghana's coast, where cetacean landings are highest. ...
... The Dixcove village holds a large community of driftgillnet fishermen in the Ahanta district in the Western Region on Ghana's coast, where cetacean landings are highest. During the latest port-based survey in Dixcove, results indicated that daily cetacean landings in a single fishing port may have increased from 0.74 animals per day in 2001(Debrah et al., 2010 to 2.82 animals per day in 2013. Generally, cetacean carcasses are often used as bait in shark fisheries but most captured animals seem to be landed, butchered and sold for human consumption, the co-called trade in marine bushmeat (Alfaro-Shigueto and Van Waerebeek, 2001;Ofori-Danson et al., 2003;Clapham and Van Waerebeek, 2007). ...
Article
Full-text available
Within the Gulf of Guinea high levels of fisheries-related cetacean mortality (bycatch and direct-capture) has been documented. For locally rare species such removals could potentially lead to significant population level effects. However, information on the cetacean abundance and distribution is scarce. Similarly, it remains largely unreported where fishing fleets operate offshore. A cetacean survey took place during geophysical surveys (2013–2014) along the coasts of Ghana and Côte d’Ivoire. This provided a unique opportunity to study both offshore cetacean and fishing communities. Due to large group-sizes, melon-headed whales were the most abundant (0.34 animals km−1) followed by Fraser’s dolphins and short-finned pilot whales. Range state records were confirmed for melon-headed whale and Fraser’s dolphin in Ivoirian waters and ten further species represented first at-sea sightings. The artisanal fishing canoe was most abundant (92% of all vessels) and recorded up to 99.5 km from the Ghanaian coast. Asian trawlers operated over shelf areas and tuna purse-seine vessels in deep oceanic and slope waters. Fraser’s dolphins, melon-headed whales, pantropical spotted dolphins, bottlenose dolphins, and pilot whales were recorded in areas with the highest fishing densities. Melon-headed whales, pilot whales, and rough-toothed dolphins were observed in vicinity of trawlers; bottlenose dolphins, pantropical spotted dolphins, and pilot whales in vicinity of canoes. Some notable differences were found in the species composition between the present surveys and port-based surveys of landed cetaceans (bycatch/direct-captures). These may be explained by (1) feeding strategies (nocturnal vs. diurnal; surface vs. deep water); (2) different attractions to vessels/fishing gear; (3) variable body sizes; and (4) difficulty to positively identify species. Despite these differences, both cetaceans and fishing vessels predominantly occurred in shelf and slope waters (< 1000m depth contour), making fishery-related mortality likely. The poor knowledge on population trends of cetaceans in this unique upwelling region, together with a high demand for cetacean products for human consumption (as “marine bushmeat”) may lead to a potential decline of some species that may go unnoticed. These new insights can provide a foundation for the urgently required risk assessments of cetacean mortality in fisheries within the northern Gulf of Guinea.
... Small cetaceans were originally obtained as bycatch, however, direct catches now occur, at least in Apam, Dixcove, and Axim, where landing rates have greatly increased since the mid-1990s. For example, landings in Apam increased from 1.117 per month in the period 1995, to 5.57 between 2001and 2003(Ofori-Danson et al., 2003Debrah et al., 2010). Further, between January 2013 and February 2014, a minimum of 743 small cetaceans were landed at Dixcove alone, which represents an increase of almost 400% since 2003 (Debrah et al., 2010;Van Waerebeek et al., 2014). ...
... For example, landings in Apam increased from 1.117 per month in the period 1995, to 5.57 between 2001and 2003(Ofori-Danson et al., 2003Debrah et al., 2010). Further, between January 2013 and February 2014, a minimum of 743 small cetaceans were landed at Dixcove alone, which represents an increase of almost 400% since 2003 (Debrah et al., 2010;Van Waerebeek et al., 2014). The entire animal, bones attached, is hacked into small, individual portions for sale, which explains the lack of bony remains on beaches (Van Waerebeek and Ofori-Danson, 1999). ...
... The entire animal, bones attached, is hacked into small, individual portions for sale, which explains the lack of bony remains on beaches (Van Waerebeek and Ofori-Danson, 1999). All body parts are used, including the internal organs, both for food and as bait (Ofori-Danson et al., 2003;Weir et al., 2008;Van Waerebeek et al., 2009Debrah et al., 2010;Robards and Reeves, 2011;Weir and Pierce, 2013). Manatees hold different values between communities, some of which hunt them for food (Powell, 1996;Amlalo, 2008) while others kill them for bait . ...
Article
Full-text available
Aquatic bushmeat can be defined as the products derived from wild aquatic megafauna (e.g., marine mammals) that are used for human consumption and non-food purposes, including traditional medicine. It is obtained through illegal or unregulated hunts as well as from stranded (dead or alive) and bycaught animals. In most South American and West African countries aquatic mammals are or have been taken for bushmeat, including 33 small cetaceans and all three manatee species. Of these, two cetacean species are listed in the IUCN red list as “near threatened,” and one as “vulnerable,” as are all manatee species. Additionally, 22 cetacean species are listed as “data deficient,” hence some of these species may also be at risk. No reports (recent or otherwise) were found for some countries, caution is needed in concluding that aquatic bushmeat is not utilized in these nations. Moreover, although aquatic bushmeat is mostly obtained opportunistically and was likely originally taken only for local consumption, directed catches occur in most countries and may have reached unsustainable levels in some areas. For example, in Peru and Nigeria, thousands of small cetaceans are illegally hunted annually. Reliable, recent data and a better overall understanding of the drivers of aquatic bushmeat will be essential in the development of effective mitigation measures.
... The relatively few surveys of fisheries interactions covered limited periods and areas (e.g. Maigret, 1981;Van Waerebeek et al., 2000;Mullié et al., 2004;Zeeberg et al., 2006;Collins et al., 2004;Ayissi et al., 2014; as no systematic monitoring of cetacean mortality exists along western African coasts (Weir and Pierce, 2012) perhaps with the single exception of the port of Dixcove, Ghana (Van Waerebeek and Ofori-Danson, 1999;Ofori-Danson et al., 2003;Debrah et al., 2010;Van Waerebeek et al., 2014). ...
... In 1998-2000, T. truncatus was the third most commonly landed species in Ghana ports with 15.5% of recorded landings (n=58) (Ofori-Danson et al., 2003). In a more comprehensive sample covering 1994-2010 (n=212), T. truncatus accounted for a somewhat lower 12.3% of documented cetacean landings, while still ranking third species behind Clymene and pantropical spotted dolphins (Debrah et al., 2010). More recently, of 743 small cetaceans reported landed at Dixcove (January 2013-February 2014 catch data), 109 were supported by identifiable photos of which 6.4% were confirmed T. truncatus, now ranking only 5 th among captured cetacean species . ...
... Van Waerebeek et al., 2015;, however the Dixcove-type commercial exploitation including the practice of directed dolphin takes (hunting) is a fairly recent development and poses a vastly bigger threat to small cetacean populations (e.g. Ofori-Danson et al., 2003;Debrah et al., 2010;Van Waerebeek et al., 2014). ...
... Waerebeek, 2010) [6,16,26]. In contrast with the situation observed in neighbouring Togo, where the overt landing of dolphins is not permitted (Segniagbeto et al., 2019) [20], within the Ghanaian ports, these animals are landed and sold without impediment. ...
Article
Full-text available
Dolphins and whales are collectively referred to as cetaceans which have until recently remained unstudied in Ghana and within the Gulf of Guinea. In recent times, the growing increase in the landings and stranding of cetaceans have raised concern to environmental�ists and the general public even though Ghana has enacted several legislations intended to foster the conservation of biodiversity and protection of the environment. Some of these include United Nations Convention on Migratory Species (UN/CMS) and United Nations Convention on Biodiversity (UN/CBD). The concernshave been heightened since March 2021 by the mass stranding of melon-headed whales (Peponocephala Electra), along the beaches of Axim on the western coast of Ghana. Although it is not immediately clear as to the plausible causes of the stranding, some postulations have been made based on sequential observations over time in this paper to help guide mitigating measures and aid in raising public awareness. Among the potential multifactorial causes postulated include the joint naval exercises taking place in and around Ghana’s offshore deep-water areas in response to the escalating piracy along the Gulf of Guinea in recent times; the presence of biotoxins and chemical pollutants and poisons arising from ‘red tides’; and the increased maritime vessel traffic along West African waters due to the closure of the Suez Canal compelling vessels to traverse the Cape of Good Hope around South African. These thus are rife with plausible increased ship strikes of the animals, and the possibility of a pandemic, resulting from dolphin morbillivirus (DMV). Suggestions and recommendations have been provided to guide the collection of needed data to facilitate the process of policy, ocean governance and development of management strategies.
... Rough-toothed Dolphins are killed incidentally in tuna purse seines in the eastern tropical Pacific: 21 were estimated to have been killed during the period 1971-75 and 36 died in a single net haul in 1982. In Ghana, Rough-toothed Dolphins were reported to comprise 6.1% of cetacean bycatches in gillnets (Van Waerebeek et al. 2009, Debrah et al. 2010. From 1992 to 1998 in Ceara State, northeastern Brazil, 13 strandings of this species were recorded, all likely due to gillnet entanglement (Monteiro-Neto et al. 2000). ...
... Although Pygmy Killer Whales comprised less than 2% of all cetaceans bycaught in gillnet fisheries in Trincomalee and in villages on the south-west coast of Sri Lanka, this may have amounted to 300-900 Pygmy Killer Whales each year (Ross and Leatherwood 1994). Small incidental catches are known to have occurred in fisheries in other areas including the Philippines, Taiwan, and Ghana (Ross and Leatherwood 1994, Dolar 1994, Perrin et al. 2005, Debrah et al. 2010). ...
... The only direct catches of this species occur in small-scale hunts in parts of the Caribbean (Saint Vincent), possibly in West Africa and possibly in the Azores (Jefferson et al. 2015, Perrin et al. 1994. In one study conducted in Ghana, Atlantic Spotted Dolphins comprised only 0.5% of the cetaceans that were brought to port (Debrah et al. 2010). In Venezuela, dolphin carcasses are (or at least were historically) used for shark bait and for human consumption (Perrin et al. 1994). ...
... There is further evidence of significant bycatch where monitoring programs have been established. For example, Debrah et al. (2010) reported regular cetacean landings at ports in Ghana and Hazevoet and Wenzel (2000) reported that dolphins could be found regularly in the markets of the Cape Verde Islands. ...
Technical Report
Full-text available
Book
Full-text available
Butterworth, A., Simmonds, M. P., eds. (2017). People – Marine Mammal Interactions. Lausanne: Frontiers Media. doi: 10.3389/978-2-88945-231-6 Our relationships with marine mammals are complex. We have used them as resources, and in some places this remains the case; viewed them as competitors and culled them (again ongoing in some localities); been so captivated and intrigued by them that we have taken them into captivity for our entertainment; and developed a lucrative eco-tourism activity focused on them in many nations. When we first envisaged this special topic, we had two overarching aims: Firstly, we hoped to generate critical evaluation of some of our relationships with these animals. Secondly, we hoped to attract knowledgeable commentators and experts who might not tradi- tionally publish in the peer-reviewed literature. We were also asking ourselves a question about what responsibility mankind might have to marine mammals, on our rapidly changing planet? The answer to the question; can, or should, humans have responsibility for the lives of marine mammals when they are affected by our activities? - is, in our opinion, ‘yes’ – and the logical progression from this question is to direct research and effort to understand and optimise the actions, reactions and responses that mankind may be able to take. We hope that the papers in this special issue bring some illumination to a small selection of topics under this much wider topic area, and prove to be informative and stimulating.
Conference Paper
Full-text available
To date, six cetacean species are confirmed to occur in coastal waters off Ghana: five odontocetes Stenella clymene, Steno bredanensis, Tursiops truncatus, Kogia sima, Physeter macrocephalus, and Megaptera novaeangliae. A stranded humpback whale calf raised questions about breeding stock. We found no evidence for the presence of the Atlantic hump-backed dolphin Sousa teuszii ; either it has become rare or it does not occur off Ghana. Unrestrained coastal development may pose a threat for nearshore species. Regular and year-round by-catches of small cetaceans are documented in artisanal gillnet fisheries from Apam, Jamestown (Accra), Kpone and Winneba. At Apam, drift gillnet fishermen intentionally capture dolphins with sharks and tuna. Annual takes at Apam and Jamestown probably count in the low hundreds, higher than at Kpone and Winneba. Bottlenose dolphins are also known to be taken in semi-industrial purse-seines (Jamestown). Carcasses are not filleted, but hacked into small portions including bone, and retailed locally for food. This explains why beach-combing around fishing villages did not yield any findings of skeletal parts. Field research and monitoring effort should continue.
Article
Full-text available
A total of 2 077 records of approximately 49 000 small cetaceans, including dedicated and incidental sightings and specimens, was analysed to define distribution patterns of the 28 species found within southern African waters. Distribution analyses reveal distinct component patterns, including cosmopolitan (found in all waters) and pelagic cosmopolitan (found in all pelagic waters) components, tropical, subtropical and warm temperate components of the Agulhas Current system, an Agulhas Bank component, a South and East Coast inshore component, and West Coast neritic and pelagic components. While the offshore distribution appears to be determined by water depth, possibly through distribution of the principal prey, longshore distribution appears to be determined by water temperature. The high diversity of small cetacean species found within the relatively small study region results from the wide range of zoogeographic components present. These components arise from the wide range of water temperature resulting from the warm Agulhas Current and the upwelling Benguela system.
Chapter
Full-text available
Information on small cetacean mortality in Peruvian fisheries is reviewed for 1990-1993 period, after the national ban on cetacean exploitation. The ban was found not to be enforced or at best only partially so. Principal species affected included Lagenorhynchus obscurus, Delphinus capensis, Phocoena spinipinnis and Tursiops truncatus. -from Authors
Conference Paper
Full-text available
An interview survey among artisanal fishermen from Brass Island, Niger Delta, in 2008­2009 revealed, for the first time, regular takes of delphinids in Nigerian coastal waters. Three fishermen at Imbikiri, Brass Island, were identified as dedicated 'dolphin hunters'. Evidence is difficult to obtain but one video footage authenticated the landing of a live common bottlenose dolphin. Fraser's dolphin is suggested to occur offshore (probable sighting) but no other documented sightings of odontocetes are published, despite the massive exploration effort for hydrocarbons. A cow­-neonate pair of humpback whales was sighted in western Nigeria, at the Togo border, on 9 September 2001 during a survey of the austral population that breeds in the Bight of Benin. In view of the abysmal state of knowledge, as to add to the inventory and zoogeography of Nigeria's cetaceans even baseline coastal surveys could yield significant insights. Particularly pressing is an in­depth assessment of the contemporary and historical presence (or absence), of the vulnerable Atlantic humpback dolphin Sousa teuszii and an estimate of the extent and composition of dolphin takes.
Article
Full-text available
An initial inventory of the dolphins and whales occurring in Guinea's coastal waters is documented primarily from specimens and photographic evidence obtained from strandings and by-catches. Seven species are fully validated, four odontocetes, Tursiops truncatus, Sousa teuszii, Stenella frontalis, Kogia breviceps and three balaenopterid whales: Balaenoptera brydei, Balaenoptera acutorostrata and Megaptera novaeangliae. Another three reported species (Globicephala macrorhynchus, Steno bredanensis and Delphinus delphis) are insufficiently supported but thought to be valid. Small cetaceans landed as by-catch and a stranded whale were used for human consumption, but no evidence of substantial takes, directed or by-catch, was found. However, concern is raised about even minimal takes of the vulnerable Atlantic humpback dolphin. The seasonal presence of three confirmed humpback whales, two strandings (July and September) and a sighting (October), is synchronous with the species' southern hemisphere wintering/breeding season in low latitudes. We hypothesize that these whales may comprise the north-westernmost range of the population that breeds/overwinters in coastal waters of the Bight of Benin, northern Gulf of Guinea.
Article
Provides a preliminary review of West African fisheries with particular attention to the problem of catches of marine mammals. The five identified artisanal gillnet fisheries do not often catch cetaceans. Foreign industrial fisheries are more likely to have an impact on cetacean populations. -from Author
Article
We detail the first direct, at sea monitoring of small cetacean interactions with Peruvian artisanal drift gillnet and longline fisheries. A total of 253 small cetaceans were captured during 66 monitored fishing trips (Gillnet: 46 trips; Longline: 20 trips) from the port of Salaverry, northern Peru (8o14′S, 78o59′W) from March 2005 to July 2007. The most commonly captured species were common dolphins (Delphinus spp.) (47%), dusky dolphins (Lagenorhynchus obscurus) (29%), common bottlenose dolphins (Tursiops truncatus) (13%) and Burmeister’s porpoises (Phocoena spinipinnis) (6%). An estimated 95% of common dolphin bycatch was of long-beaked common dolphins (Delphinus capensis). Overall bycatch per unit effort for gillnet vessels (mean ± sd) was estimated to be 0.65 ± 0.41 animals.set−1 (range 0.05–1.50) and overall catch (bycatch and harpoon) was 4.96 ± 3.33 animals.trip−1 (range 0.33–13.33). Based upon total fishing effort for Salaverry we estimated the total annual average small cetacean bycatch by gillnet vessels as 2412 animals.year−1 (95% CI 1092–4303) for 2002–2007. This work indicates that, in at least one Peruvian port, bycatch and harpooning of small cetaceans persist at high levels and on a regular basis, particularly in driftnet vessels, despite the existence since the mid-1990s of national legislation banning the capture of marine mammals and commerce in their products. It is concluded that the coast of Peru is likely still one of the world’s principal areas for concern regarding high small cetacean bycatch and there is clearly an urgent need to increase the geographic scope of observer effort to elucidate the full magnitude of this issue.