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Fish aggregating devices, named FADs, are floating objects typically used to attract and capture pelagic fish in industrial tuna fisheries. This study documents nine cases, involving 31 marine mammals of incidentally captured, killed or otherwise retrieved cetaceans and pinnipeds which were used, or presumably so, as bait with improvised Fish Aggregation Devices (IFAD) by artisanal fishers in coastal Ecuador. At least three species of small cetaceans were affected, including pantropical spotted dolphin Stenella attenuata, short-finned pilot whale Globicephala macrorhynchus, pygmy killer whale Feresa attenuata, and an unidentified small delphinid; besides South American sea lion Otaria byronia, the latter reportedly killed on purpose for this fishing practice. A sperm whale Physeter macrocephalus and a humpback whale Megaptera novaeangliae were presumably found floating at sea and opportunistically exploited as FADs. The prevalence of marine mammals used as bait associated with FADs was 80.6% for the South American sea lion (25 sea lions out of 31 marine mammals) and 19.4% for the remaining six cetacean species. This is the first report of baited FADs in Ecuador, the extent of which is still unknown. This fishing technique has not been documented in other nations along the west coast of South America, although baiting of gillnets with marine mammal parts is common in Peru. Without fisheries management and regulation, it could rapidly expand and lead to further directt kills and conservation problems for targeted marine mammal populations in the eastern tropical Pacific. A bottom-up fisheries policy in concert with community-based conservation to ban the use of marine mammals as FAD bait is recommended.
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Endang Species Res
Vol. 41: 289– 302, 2020 Published March 12
Fish aggregating devices (FADs) have traditionally
been defined as structures floating at the surface of
the ocean placed by fishers to increase fishing oppor-
tunities and specifically attract and capture both
pelagic juvenile and adult fishes, such as tropical
tuna including skipjack Katsuwonus pelamis, yel-
lowfin Thunnus albacares and bigeye Thunnus obe-
sus (Castro et al. 2002, Dempster & Taquet 2004,
Fonteneau et al. 2013, Hall & Roman 2013, Moreno et
al. 2016a). These devices are used widely in tropical
and subtropical waters, mainly in countries from the
Pacific, Atlantic and Indian Oceans which are part of
the tuna Regional Fisheries Management Organiza-
tions (RFMOs), for recreational, artisanal, industrial
and commercial fisheries with the aim to concentrate
and capture pelagic fish (Dempster & Taquet 2004,
© The authors 2020. Open Access under Creative Commons by
Attribution Licence. Use, distribution and reproduction are un -
restricted. Authors and original publication must be credited.
Publisher: Inter-Research ·
*Corresponding author:
Marine mammals used as bait for improvised fish
aggregating devices in marine waters of Ecuador,
eastern tropical Pacific
Cristina Castro1, Koen Van Waerebeek2, Diana Cárdenas1,3, Juan José Alava4,5,*
1Pacific Whale Foundation-Ecuador, Malecón Julio Izurieta, Puerto López, Manabí, Ecuador
2Peruvian Centre for Cetacean Research - Centro Peruano de Estudios Cetológicos (CEPEC), Pucusana, Lima 20, Perú
3Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ciencias de la Vida, Laboratorio para Investigaciones
Biomédicas, Campus Gustavo Galindo Km 30.5 Vía Perimetral, P.O. Box 09-01-5863, Guayaquil, Ecuador
4Fundación Ecuatoriana para el Estudio de Mamíferos Marinos (FEMM), Guayaquil, Ecuador
5Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
ABSTRACT: Fish aggregating devices (FADs) are floating objects typically used to attract and
capture pelagic fish in industrial tuna fisheries. This study documents 9 cases, involving 31 marine
mammals, of incidentally captured, killed or otherwise retrieved cetaceans and pinnipeds which
were used, or presumably used, as bait for improvised fish aggregation devices (IFAD) by arti-
sanal fishers in coastal Ecuador. At least 3 species of small cetaceans were affected, including
pantropical spotted dolphin Stenella attenuata, short-finned pilot whale Globicephala macro -
rhynchus, pygmy killer whale Feresa attenuata and an unidentified small delphinid, as well as
South American sea lions Otaria byronia which were reportedly killed on purpose for this fishing
practice. A sperm whale Physeter macrocephalus and a humpback whale Megaptera novaean-
gliae were presumably found floating at sea and opportunistically exploited as FADs. The South
American sea lion represented 80.6% of marine mammals used as bait associated with FADs (25
sea lions out of 31 marine mammals), while the remaining 5 (possibly 6) cetacean species repre-
sented 19.4%. This is the first report of baited FADs in Ecuador, the extent of which is still
unknown. This fishing technique has not been documented in other nations along the west coast
of South America, although baiting of gillnets with marine mammal parts is common in Peru.
Without fisheries management and regulation, this illegal fishing practice could rapidly expand
and lead to further direct kills and conservation problems for targeted marine mammal popula-
tions in the eastern tropical Pacific. A bottom-up fisheries policy in concert with community-based
conservation to ban the use of marine mammals as FAD bait is recommended.
KEY WORDS: Cetacean · Pinniped · Sea turtles · Bycatch · Bait · Conservation · Fisheries
management · South America · Pacific Ocean
Contribution to the Special ‘Marine vertebrate bycatch: problems and solutions’
Endang Species Res 41: 289– 302, 2020
Fonteneau et. al. 2013, Gershman et al. 2015, Murua
et al. 2016). FADs can be constructed from artificial
or natural materials by the fishers, or they simply
consist of a floating object (Castro et al. 2002, Demp-
ster & Taquet 2004, Moreno et al. 2016a,b). The inter-
national tropical tuna purse-seine fisheries fleet
maintains as many as 121000 drifting fish aggregat-
ing devices (dFADs) deployed by fishers in tropical
oceans worldwide (Gershman et al. 2015, Moreno et
al. 2016a). Other oceanic megafauna and epipelagic
marine species such as sharks, sea turtles, and mar-
ine mammals also aggregate around FADs (Brehmer
et al. 2012, Dagorn et al. 2013). The potential delete-
rious impacts of FADs due to high levels of bycatch
and threats to the marine biodiversity of tropical
pelagic ecosystems have been reviewed, highlight-
ing the need for additional fisheries management
actions and an improved management plan (Dagorn
et al. 2013, Gershman et al. 2015). In particular,
pelagic sharks, sea turtles, and other vulnerable mar-
ine species are entangled and killed in these FADs
(Filmalter et al. 2013, Hall & Roman 2013, Murua et
al. 2016). Massive mortality of silky sharks Carcha-
rhinus falciformis was reported on an annual basis in
the Indian Ocean, where approximately 480000
to 960000 silky sharks are killed each year when
caught in FADs (Filmalter et al. 2013).
Ecuador has the largest small-scale (artisanal) fleet
in the southeastern Pacific (Alava et al. 2015,
Martínez-Ortiz et al. 2015). According to the Secre-
tariat of Fisheries Resources (Subsecretaría de Recur-
sos Pesqueros [SRP]), there are 234 fishing communi-
ties, with a total of 19770 to 45000 artisanal boats and
between 63970 and 87280 small-scale fishers regis-
tered as members of the current fishing population in
Ecuador (Alava et al. 2015, 2019, Martínez-Ortiz et
al. 2015). The small-scale fisheries on the Ecuadorian
continental coast are represented by the artisanal
coastal fishery, which uses small boats to fish in
coastal areas, and the artisanal oceanic long-line
fishery, which operates in the open sea with the sup-
port of a larger ship (Martínez-Ortiz et al. 2015). Both
of them capture demersal and pelagic fish. The main
fishing gear presently used include trammel or sur-
face gillnets (‘trasmallo’) of 800 m long by 3 m high,
the 3200 m long cachema longline (‘espinel corvi -
nero’) with 800 hooks, the longline (‘palangre’) of 36
to 72 m, and the purse-seine net (‘red de cerco’) up to
1300 m long and 30 m deep. In Ecuador, the small-
scale fishing fleet uses mainly longlines and surface
gillnets (mesh sizes: 7.5 to 13 cm) to catch large
pelagic fish species, including dorado or dolphin-fish
Coryphaena hippurus, several tuna, billfish species
and sharks (Alava et al. 2015, 2019, Martínez-Ortiz et
al. 2015). However, while Ecuador is one of the top
countries using drifting FADs in the tropical tuna
purse seine industrial fleet (Gershman et al. 2015),
the use of FADs has not been officially reported or
implemented in small-scale or artisanal fisheries of
The lethal interaction of small cetaceans with fish-
eries is widely recognized as one of the biggest global
conservation problems in recent decades (North-
ridge 1985, Reeves et al. 2003, Hucke-Gaete et al.
2004, Avila et al. 2018). In Ecuador, human activities
have severe direct and indirect im pacts on marine
mam mals, including deleterious fisheries interac-
tions (Félix & Samaniego 1994, Van Waerebeek et al.
1997, Alava et al. 2005a, 2012, 2019, Félix et al. 1997,
Castro & Rosero 2010, Jiménez et al. 2018), vessel
collisions with cetaceans (Van Waerebeek et al. 2007,
Félix & Van Waerebeek 2005, Félix et al. 1997), and
short-term impacts generated by whale-watching
tourism (Scheidat et al. 2004). Additionally, skin dis-
eases in marine mammals have been indirectly
linked to contaminants (Castro et al. 2008, Jiménez &
Alava 2014, Van Bressem et al. 2015).
In Ecuador, 3 types of fishing gear have been asso-
ciated with incidental captures of marine mammals:
(1) surface gillnets set mainly for pelagic fishes,
such as swordfish Xiphias gladius and billfishes
(Istio phor idae); (2) longlines of different lengths
also targeting pelagic fish; and (3) purse-seines tar -
get ing different tuna species such as yellowfin Thun -
nus albacares, bigeye, skipjack or barrilete but also
dorado, croakers (Sciaenidae, Cy nos cion spp.) (Alava
et al. 2012, 2019, Castro & Rosero 2010, Castro et al.
Prior studies have reported incidental capture rates
of dolphins by Ecuadorian fishermen in coastal
waters. Two catch rates with drift gillnets were esti-
mated in the early 1990s, ranging from 0.04 dolphins
per boat in Puerto Lopéz to 0.10 dolphins per boat for
Santa Rosa (Félix & Samaniego 1994). In the Gulf of
Guayaquil, a daily catch rate for bottlenose dolphins
Tursiops truncatus was estimated at 0.0064 dolphins
d−1, or 0.019 bottlenose dolphins per trip, but the con-
fidence intervals were very wide (Van Waerebeek et
al. 1997). The highest incidental catch rate was ob -
tained in August 2009 when 0.18 dolphins d−1 per
equivalent trip was estimated (Castro & Rosero
2010). However, there is no information about the
use of marine mammals for fishing purposes in
coastal Ecuador. At Puerto Bolívar (southern Ecua -
dor), one fisherman admitted harpooning a bottle-
nose dolphin near Puná Island, for bait in the longline
Castro et al.: Marine mammals as bait in FADs 291
fishery, while fishers operating in the Gulf of Guaya -
quil indicated they either discarded bycaught dead
dolphins at sea or, when possible, sold them for bait
to Peruvian fishermen (Van Waerebeek et al. 1997).
While industrial tuna fishing operation deploying
FADs at sea is known and managed by the Inter-
American Tropical Tuna Commission (IATTC) in the
eastern tropical Pacific (Murua et al. 2016, Gershman
et al. 2015), the emerging use of FADs with bycaught
or otherwise dead marine mammals as bait has only
recently been identified in small-scale fisheries of
Ecuador and previously reported in a working do -
cument to the International Whaling Commission
(Castro et al. 2018).
This study presents the first well-documented
records on the take and use of cetaceans and pin-
nipeds as fishing bait in continental Ecuador. The
purpose is to document and raise awareness about
the occurrence of these illicit, unregulated and un -
reported practices, suggest regulations, and pro-
mote the adoption of management efforts to im -
prove the protection of marine mammal populations
in Ecuador.
The information presented here was obtained by
the Pacific Whale Foundation (PWF) with information
from tourists, park rangers, and fishers and compiled
as a database of stranding and bycatch records, ob -
servations through fish market monitoring as well as
interviews with crew members of commercial fishing
vessels and local fishermen. Strandings information,
both from own observations and interviews with
locals, was collected opportunistically in the course
of multiple unscheduled visits to fishing ports, sur-
rounding beaches and other coastal locations of con-
tinental Ecuador in the period 2009 to 2019 (Fig. 1,
Table 1). Although daily search effort data were not
logged, between June 2001 and March 2017 the car-
casses of 130 cetaceans belonging to 18 species were
documented in the PWF database as stranded on the
coasts of continental Ecuador (Castro & Van Waere-
beek 2019). Only stranding records where we
observed fishing gear, indications of baiting, cutting,
tethering or other evidence of human manipulation,
were taken into account in the present study. Cases 1
Fig. 1. Ecuador’s continental coast showing the fishing villages and ports (Cojimíes, Pedernales, Puerto Lopez, Salango and
Las Tunas) in Manabí Province, where cases of marine mammals used as bait and/or associated with improvised fish aggregating
devices (IFADs) were found from 2009 to 2019
Endang Species Res 41: 289– 302, 2020
Case Date Location No. of Species CC IUCN category Observations
( ind. (international/national)
CITES status
1 10.11.09 Between Cojimíes 17 South American 3−4 International: Carcasses associated with
and Pedernales sea lion (Otaria byronia) Least Concern ropes and buoys
(0° 22’ 4” N, 80° 2’ 7” W) National: N/A
2 10.11.09 Between Cojimíes 1 Sperm whale 3−4 International: Stranded carcass associated
and Pedernales (Physeter macro- Vulnerable with ropes and buoys;
(0° 22’ 4” N, 80° 2’ 7” W) cephalus) National: Vulnerable: 1 marine turtle found nearby
(Alava et al. 2011a)
CITES Appendix I
3 23.11.12 Puerto López 1 Spotted dolphin 4 International: Carcass and rope tied
(1° 33’ 60” S, (Stenella attenuata) Least Concern tailstock
80° 48’ 60” W) National: Vulnerable
(Alava et al. 2011b)
CITES Appendix II
4 11.08.14 Salango 1 Sea lion 3−4 International: Bloated animal floating with
(1° 35’ 0” S, 80° 51’ 0” W) (likely O. byronia) Least Concern holes and thin black rope
National: N/A tied to the body
5 15.06.16 Puerto López 1 Unidentified small 4 Carcass exhibiting skin with
(1° 33’ 60”S, 80° 48’ 60”W) delphinid cut marks
6 17.09.16 Puerto López 1 Pygmy killer whale 4 International: The animal had its head
(1° 33’ 60” S, 80° 48’ 60”W) (Feresa attenuata) Least Concern severed and missing tail
Near Threatened
(Alava et al. 2011c)
CITES Appendix II
7 30.09.16 Cojimies 7 Sea lion 3−4 International: Skeletal remains and car-
(2° 20’ 0’’N, 80° 02’ 00’’W) (likely to be O. byronia) Least Concern casses entangled with nylon
National: N/A rope connected with weights
and buoys. Presence of float
tanks, purse seine or gillnet,
and wooden structure with
floats. Four more sea lions
were found nearby
8 30.09.16 Cojimies 1 Short-finned pilot whale 3−4 International: Carcass with both dorsal fin
(2° 20’ 0’’N, 80° 02’ 00’’W) (Globicephala macro- Least Concern and flukes missing;
rhynchus) National: presumably a shark bite and
Near Threatened other damage. Rope,
(Castro et al. 2011a) weights, and buoys, as part
CITES Appendix II of a FAD, were attached.
3 dead sea turtles were
found at the same location
9 28.07.19 Las Tunas 1 Immature humpback 4 International: Carcass washed ashore with
(1° 39’ 0” S, 80° 49’ 15” W) whale (Megaptera Least Concern shark bites but no other
novaeangliae) National: Vulnerable visible traumata; light nylon
(Castro et al. 2011b) line attached to the tailstock.
CITES Appendix I Presumably collected and
used by fishermen
Table 1. Documented cases of marine mammals utilized as bait with improvised Fish Aggregating Devices (IFADs) on the
Ecuadorian coast from 2009 to 2019. Carcass condition codes (CC) follow Geraci & Lounsbury (2005) —1: alive, 2: freshly dead, 3:
early decomposition, 4: advanced decomposition, 5: bare bones or mummified. Cases 2 and 9 are unconfirmed but highly probable
cases. Conservation categories of the IUCN were based on IUCN (2019) at the international level and on various contributions to the
Red Book of Ecuador’s mammals (Tirira 2011) for the IUCN national categories in Ecuador. The CITES status was retrieved from the
checklist of CITES Species ( N/A: not available
Castro et al.: Marine mammals as bait in FADs
and 2 are based on information received from the
Municipality of Pedernales, Manabí province (Fig. 1)
and examination of photos for these specific cases
(Table 1) available online (information published by
the newspaper El Diario 2009). Condition codes of
carcasses (CC) were determined according to Geraci
& Lounsbury (2005), briefly, as follows: 1: alive;
2: reshly dead; 3: early decomposition; 4: advanced
de composition; 5: bare bones or mummified.
A FAD is defined as a floating man-made object or
structure used to attract ocean going pelagic fish,
such as tuna, billfish, and dorado. They usually con-
sist of buoys or floats tethered to the ocean floor with
concrete blocks. Industrial fisheries utilize large, com-
mercially produced FADs made of metal and plastic
floats, so they can be used for long periods (Morgan
2011a, Moreno et al. 2016a); however, there is a
recent tendency to replace these fishing devices with
biodegradable materials such as bamboo, palm
leaves, coconut fiber, and cotton (Moreno et al. 2016b,
Murua et al. 2016). For instance, efforts to test and
implement biodegradable FADs are underway in
Ecuador (Tunacons 2019). Once deployed at sea,
they are rarely lifted out of the water.
3.1. Marine mammals as bait
We found that smaller, improvised FADs (IFADs) fab-
ricated and used by artisanal fishers (Fig. 2) were often
baited with marine mammal remains. Nine cases of
marine mammal strandings that had been used as bait
(2 suspected) were registered at 4 different locations
along the coast of Manabí Province, i.e. Cojimíes-Ped-
ernales, Puerto López, Salango and Las Tunas (i.e. from
39’ 0’S, 80° 49’ 15’’ W at Las Tunas to 0° 22’ 4’’N,
80° 2’ 7’’W at Cojimíes-Pedernales) from 2009 to 2019
(Table 1, Fig. 1), but with strandings survey effort since
2001. When found washed ashore or floating nearshore,
carcasses were either directly attached to a FAD or
wrapped in some assemblage of fish netting, lines,
and buoys, with clear indications that they had been
handled by people and were not simply the result of
accidental entanglement in fishing gear (Figs. 3−6).
In total, 31 individuals of 6 (potentially 7) different
marine mammal species were determined as used for
bait associated with a FAD. The species most fre-
quently encountered was South American sea lion
Otaria byronia, with a prevalence rate of 80.6% (i.e.
25 out of 31 individuals) relative to the total number
of carcasses observed (Figs. 3 & 5), but 3, potentially
4, species of Delphinidae were also found: 1 pan -
tropical spotted dolphin Stenella attenuata (Fig.
4A), 1 unidentified small delphinid (Fig. 4C,D), a
short-finned pilot whale Globicephala macro rhyn -
chus (Fig. 4E,F), and a pygmy killer whale Feresa
attenuata, accounting for 19.4% of the reported car-
casses identified as FAD bait (Table 1). Two large
ceta ceans, including an odontocete (sperm whale
Physeter macrocephalus) and mysticete (humpback
whale Megaptera novaeangliae), were probably
found floating at sea and may have been opportunis-
Fig. 2. Conceptual illustration of the improvised fish aggregating device (IFAD) found on Cojimíes Beach, Ecuador, on 9 No-
vember 2009. The IFAD is assembled as a rectangular or square wooden raft or platform made of bamboo or wood fully or par-
tially covered and wrapped with mesh netting and tied up with ropes along the perimeter of the raft; gillnets or other fishing
nets with floats (plastic containers or bins), containing dead bodies or remains of marine mammals as bait, are connected
through ropes to the 4 corners of the raft. Illustrator: Alejandra Loaiza
Endang Species Res 41: 289– 302, 2020
tically exploited as IFADs by artisanal fishers. This
may be a common practice considering that acciden-
tal entanglements and ship strikes of sperm and
humpback whales have been occurring frequently in
Ecuador for decades (e.g. Haase & Félix 1994, Alava
et al. 2005a, 2012, Félix et al. 1997, Castro & Van
Waerebeek 2019). On 2 occasions, more than 1 large
marine ver tebrate was found associated with IFAD
parts and gear on the same beach in Cojimíes, Man-
abi Prov ince (Table 1). The animals associated with
IFADs had washed ashore, or were found floating
nearshore, as shown in Figs. 3−5, with remains of
ropes, floats, and weights, which in some cases were
attached to a still intact IFAD (Figs. 4 & 5). Compar-
ing the total number of stranded, dead marine mam-
mals (i.e. 5 cetaceans and 25 sea lions) associated
with IFADs as bait (n = 30 individuals, excluding the
humpback whale reported in 2019; Table 1) to the
total number of marine mammal strandings (n = 168
individuals, including cetaceans and pinnipeds such
as O. byronia and Arctocephalus sp.) from 2001 to
2017 (Castro & Van Waerebeek 2019, PWF database
unpubl. data), it is roughly estimated that approxi-
mately 18% of stranded marine mammals were asso-
ciated with IFADs.
The carcasses were mainly in an advanced state
of decomposition (condition code, C.C. = 4), as most
had apparently been found some time after the
stranding occurred, their skin was sunburnt, and
many showed holes typically made by scavenging
ghost crabs (Ocypodidae) and black turkey vultures
Coragyps atratus, which are common on Ecuador’s
beaches. Also, some bare bones were found
wrapped in small-mesh netting tied to large floats
(Case 7; Fig. 5) where all soft tissues had already
been scavenged by fishes or other marine organ-
isms. Certain cases deserve further comments, as
Case 1. On 9 November 2009, the regional news -
paper 'El Diario' published an article on the strand-
ing of 17 sea lions, 1 sperm whale and 1 sea turtle
(unidentified species) on the beach between Coji -
míes and Pedernales, Manabí Province. Unfortu-
nately, the dead animals were in an advanced state of
decomposition and quickly buried without ne cropsy
or scientific analysis. This seems to be the earliest
reported stranding event related to the use of marine
mammals as FAD bait in Ecuador. The Municipality
of Pedernales first raised the notion that the cause of
those strandings was associated with the use of FADs
by fishers (El Diario 2009). Although >1 IFAD was
likely in volved, we continued treating this as a single
Cases 7 & 8. Another multiple-species FAD stranding
consisting of 7 sea lions (probably South American sea
lions O. byronia) and a short-finned pilot whale, along-
side 3 unidentified sea turtles was registered in Co-
jimíes in September 2016 (Table 1). Five sea lions were
tied with thin ropes to the same structure, with weights
and floats; the 2 others were found detached along
the same beach (Fig. 5A− D). The ske -
letal remains of some sea lions were
wrapped in netting tied to a wooden
structure with floats and a tank
(Figs. 5E−G). The pilot whale had cuts
in the dorsal fin and tail, possibly where
it was tied to the structure or some
floating tank (Fig. 4E,F). Several com-
ponents used in IFADs were observed
as shown in Fig. 5C− G. The IFAD was
found on the beach attached to green
plastic flotation tanks (Fig. 5G). Black
gillnet-like netting holding the com-
plete carcasses of sea lions was found
attached at both sides (Fig. 5E). In one
net, only bare bones were found, sug-
gesting that perhaps this bait was in
place for an ex tended time (Fig. 5G).
The origin of the FAD is unknown, but
due to its size, it is likely that it was be-
ing used by a larger fishing boat before
it was lost or broke loose from its moor-
ings and then washed ashore.
Fig. 3. The decomposing body of a South American sea lion (Case 4) found
floating near Isla Salango on 11 August 2014. A nylon rope was tied (not en-
tangled) around the forebody and around the base of the pectoral fins. Photo:
Pacific Whale Foundation
Castro et al.: Marine mammals as bait in FADs
Case 9. The single wrap of a 7−8 mm nylon cord
around the tailstock of the subadult humpback
whale appeared to be a human intervention on a
carcass (Fig. 6A). A live whale of this size would have
readily snapped such a light line had it been an acci-
dental entanglement with fishing gear. However, this
cord is thought to have held a dead floating whale
tethered as a Type 1 FAD (see Section 3.2) to some
fishing gear. Local rangers (Machalilla National Park)
blamed the industrial fishery (pers. comm. to KVW);
however, no evidence puts the artisanal fishery be -
yond suspicion. The cause of death of the whale re -
mained unknown, but ventrally no signs of traumata
were visible except (most likely postmortem) shark
bites (Fig. 6B). Unfortunately, no necropsy could be
performed as the carcass was quickly buried on the
beach by a Municipality backhoe loader.
3.2. Improvised fish aggregating devices
Artisanal fishermen do not seem to invest in the
large commercially available FADs. Instead, they
make their own: far simpler and smaller versions
(Figs. 2 & 4E,F), which we refer to as improvised
fish aggregating devices (IFADs). We suggest that
most of the latter are baited with the remains of mar-
ine mammals or sea turtles, often involving several
Fig. 4. Carcasses and remains of cetacean species associated with and used as bait in improvised fish aggregating devices
(IFADs). (A) Pantropical spotted dolphin (Case 3) as found on a Puerto López beach, on 23 November 2012; (B) the dolphin had
green nylon rope firmly tied to its tailstock, and floats attached (not shown here). (C, D) Body and head of unidentified del-
phinid (Case 5) found stranded at Puerto López on 15 June 2016; the body showed cut marks and sunburn. (E) Anterior upper
jaw of juvenile short-finned pilot whale (Case 8) found at fishing port of Puerto López; (F) evident cut-marks on the short-
finned pilot whale indicated utilization, almost certainly for baiting FADs. Note bulbous head in dorsal view consistent
with G. macrorhynchus, which is also thought to be a bycatch victim. Photos: Pacific Whale Foundation
Endang Species Res 41: 289– 302, 2020
specimens simultaneously (see illustration in Fig.
2). Based on field observations and comments pro-
vided by fishers, we provisionally distinguish 3
types of IFADs found washed ashore, the difference
being the presence or absence of floats and the type
of construction and materials used.
Type 1. Marine mammal carcasses moored with
thin ropes by their pectoral fins, body or tailstock.
They are possibly moored to certain fishing gear, and
they remain floating by their own decomposition-
enhanced buoyancy, attracting fish. No floats are
present. This type of IFAD is used by artisanal fishers
Fig. 5. Carcasses and skeletal remains of sea lions (probably South American sea lions, Otaria byronia) used as bait in impro-
vised fish aggregating devices (IFADs) (Case 7). (A,B,C) Two of 7 sea lions (Case 7) found in association with IFADs on
Cojimíes beach on 30 September 2016. Note (A) a black rope wrapped around the body and (B) the presence of white nylon
rope doubly wrapped and knotted around the flippers (not accidentally entangled). (C) Floats were attached to the lines (white
arrow), and (D) lead weights were also present. At least 4 different colored lines were used. (E,F,G) The skeletal remains of 2
sea lions (E,G) were also attached to the IFADs with recognizable pinniped scapula, humerus, and ribs, wrapped in small-
mesh netting. (F,G) Note the assembled raft covered with black mesh tied up with blue and green ropes and a yellow float on
it. (G) A green plastic bin used as a float, tied to mesh netting with green ropes and attached to the raft was also found. Photos
A−D by Pacific Whale Foundation. Photos E, F, and G courtesy of Johana Moreira, Ministry of Environment of Ecuador
Castro et al.: Marine mammals as bait in FADs
(Figs. 3 & 4B). We suspect that floating dead whales
may be used in this way, such as the sperm and
humpback whales found stranded in Pedernales
and Las Tunas, respectively.
Type 2. Marine mammals wrapped in netting and
tied to plastic floats to increase and prolong buoy-
ancy. The nets are heavier and have weights and
floats with mooring lines. Possibly used by artisanal
fishermen, chinchorreros and others (Fig. 5A−C).
Type 3. Marine mammals wrapped in fishing nets
but at the same time tied to floats supporting larger,
mostly rectangular wooden and bamboo structures,
which can hold several bait-carcasses simultaneously
(Fig. 5E−G); possibly used also by larger, semi-indus-
trial fishing boats.
Although no observations have been made of
operating baited FADs at sea, they are thought to
function by attracting smaller marine organisms
including small fish to feed on the bait, which
then, in turn, may attract and concentrate larger
fish species (tuna, billfishes, and sharks). The latter
are easily encircled by purse-seines or taken by
other means (e.g. long-lines), as is done with com-
mercial FADs.
Interviews with artisanal fishers revealed that small
cetaceans are obtained from incidental captures in
fishing nets, while sea lions if still alive following net
entanglement were beaten to death. According to
some artisanal fishers, the use of marine mammals as
bait is carried out only by industrial tuna fisheries
and ‘chinchorreros’ (purse-seine) who take advan-
tage of the night to opportunistically fish for other
species such as dorado using FADs. The name in
Spanish for this kind of FAD is ‘plantado’ (Morgan
2011b). However, some interviews revealed that arti-
sanal fishermen were also using small cetaceans and
sea lions obtained opportunistically, referred to as
‘siembra’. Thus, the words ‘plantado’ and ‘siembra’
are synonyms, applied to industrial or artisanal fish-
ing, respectively.
Based on anecdotal information from fishers, the
use of dead marine mammals as bait in FADs is very
effective, due to their strong smell, high amount of fat
and long permanence in the water. An interviewed
fisher from Puerto López stated: ‘The best thing to
catch dorado fish is the fat of sea lions and dolphins,
with which [the FAD] is baited as these remains stay
intact for several days’.
Here we reported the first cases of cetaceans and
sea lions used as bait in IFADs in artisanal fisheries
in Ecuador. Several questions were raised by our
findings. The main concern is to what ex tent impro-
vised FADs are used by Ecuadorean artisanal fish-
eries and since when. Also, the incidence of baiting
IFADs, whether it is standard practice or only an
occasional one, remains unclear. As it stands, the
available evidence is insufficient to clarify if the
observed mixed-species arrangements were a coinci-
dence or were arranged by design. Conceivably, each
bait species may have different characteristics, e.g.
decompose at a different pace, preferentially attract
different marine organisms, or other.
In 2 cases (Cases 2 and 8), dead sea turtles were
also observed washed ashore in close association
with IFADs (Table 1), raising the question whether
they were also applied as bait. If so, these would be
the first reports that we know of. However, since
these marine reptiles are confirmed entanglement
victims of commercial FADs drifting in open waters
(Fonteneau et al. 2013), it is challenging to uncover
the causality of their presence in and around the
stranded IFADs described here. As accidental entan-
Fig. 6. (A) Carcass of a subadult humpback whale with a nylon cord around the tailstock found in Las Tunas beach on 28 July
2019. (B) Note the ventral view of the whale with tailstock showing evidence of shark scavenging. Photos: Pacific Whale Foun-
dation (A) & K. Van Waerebeek (B)
Endang Species Res 41: 289– 302, 2020
glements cannot be excluded, more field research
will be needed to provide the necessary answers.
Indeed, the issue is further confounded by insights
from other sea turtle stranding events along Ecuador’s
coast. Strandings of olive ridley Lepidochelys oli-
vacea and green sea turtles Chelonia mydas are
common on Ecuador’s beaches (see Alava et al.
2005b). Massive die-offs have also been documented
(Alava et al. 2005b, Herrera et al. 1999). These
stranding episodes were associated with environ-
mental/ natural factors (e.g. changes in sea surface
temperature, food availability, parasitic and other
diseases) and anthropogenic impacts, including fish-
eries interactions, mainly bycatch in gillnets and
longlines, and boat collisions (Herrera et al. 1999,
Alava 2000, Alava et al. 2005b). While the FADs used
by industrial fisheries in Ecuador have begun to be
managed and regulated by the IATTC (Gershman et
al. 2015, 2016, 2018, Murua et al. 2016), artisanal
fishers have re quested regulation from the Ecuado-
rian Government (Castro et al. 2018). There are indi-
cations that industrial fishers may also have started to
bait FADs to increase effectiveness, but this has not
been substantiated. It is reasonable to believe that
the lack of enforcement of relevant legislation, regu-
lation, and control regarding the use of FADs may
have allowed artisanal fishermen in Ecuador to start
using baited IFADs so as to improve their fishing
operations. It will be difficult to study the extent of
use and evaluate the impact of this activity consider-
ing that the IFADs are hard to visibly trace when
deployed at sea. Indeed, the few IFADs that were
documented had reached the shore and were
encountered by chance. A well-designed interview
study might shed some light on these aspects, but a
considerable degree of re sistance and some false
declarations should be expected.
Little is known of the potential use of baited FADs
in waters of neighboring countries and where this
practice first arose. There is no evidence, for in -
stance, that baited FADs are or have been deployed
off Peru, Chile, or Colombia. However, the use of
small cetaceans as bait in longline fisheries, espe-
cially for sharks, has long been widespread in Peru
(e.g. Van Waerebeek & Reyes 1994, Van Waerebeek
et al. 2002, Mangel et al. 2010) and was also docu-
mented in Pacific Colombia (Avila et al. 2008). More
recently, Peruvian gillnet fishermen have re sorted to
attaching butchered parts of small cetaceans directly
to wide-mesh multifilament gillnets to attract sharks,
rays, and other large fishes; in some ways these are
similar to a Type 1 improvised FAD, but structured
FAD devices with floats (Type 2 and 3) have so far not
been documented. In a survey of fishing operations
of some artisanal fishing boats in Salaverry in 2005 to
2007, Mangel et al. (2010) found that 29% of small
cetaceans by-caught in gillnets were used as bait.
Also, all harpooned dolphins, both by gillnet and
longline vessels, were used as bait (Mangel et al.
The direct hunting (harpooning) of bottlenose dol-
phins for trading of meat as bait in the Gulf of
Guayaquil has also been documented and anecdo-
tally reported by artisanal fishers and rangers, but
the current status of this practice has yet to be con-
certedly assessed in coastal Ecuador (Van Waere-
beek et al. 1997, Jiménez et al. 2018). Previous evi-
dence indicated that some fishers were eager to
pay up to USD $75 for a dolphin carcass to obtain
bait in a fishing community (i.e. Puerto López) on the
central coast of Ecuador during the 1990s (Félix &
Samaniego 1994). However, questions remain con-
cerning the presence of a systematic market to trade
bait collected from bycaught small cetaceans, and it
is likely that a small-scale black market took place on
the southern coast of Ecuador, i.e. Puerto Bolívar
(Félix & Samaniego 1994, Van Waerebeek et al.
1997), where at least one boat harpooned dolphins in
the past (Van Waerebeek et al. 1997); similarly, at
least one bottlenose dolphin was harpooned by fish-
ers close to Puna Island, Gulf of Guayaquil (Van
Waerebeek et al. 1997). As it stands, the use of a cast
net (a fishing gear locally known as ‘voladora’) by a
fisher from Posorja Harbor (Guayaquil Gulf) to
directly take bottlenose dolphins to trade their meat
in local markets was reported by rangers from the
Reserva Ecológica de Vida Silvestre Manglares El
Morro (El Morro Mangrove Wildlife Ecological
Reserve) in 2017 (Jiménez et al. 2018). The exact
purpose remains unclear, i.e. whether bycaught or
hunted marine mammals are being traded for their
use in FADs in Ecuador. Recent anecdotal informa-
tion, archived in a recorded interview of an artisanal
fisher working on a tuna fishing boat, corroborates
that this seems to be the case for South American sea
lions taken in Peruvian waters. Excerpts from the
interview are provided as follows:
‘Here, the ‘lobos marinos’ [sea lions] for ‘plantados’
[the FADs] are brought from Piura, or Pisco (Peru);
the sea lions are bought from small boats in Peru that
are dedicated to the dorado fisheries. There, they call
the dorado ‘perico’. Nowadays they buy the sea lions
during the ‘brisa’ fishing period; they purchase them
from the small vessels, then the sea lions are frozen
and stored to be used for the ‘plantados’. The ‘brisa’ is
a ‘cardumen’, a specific school of tuna fish that occur
Castro et al.: Marine mammals as bait in FADs
on these dates, from December to January… A sea
lion is cheap and costs between USD $ 70 to 100 each
one, which is a lot of money for the Peruvian fishers;
they buy between 40 to 50 sea lions, depending on
the amount of sea lions available for sale by the fish-
ers in the boats. The sea lions are not taken in
Ecuador as there are very few here and the species is
more regulated by the authorities; the sea lions are
from Peru where they are very abundant and not
regulated, except for the surveillance of the Peruvian
Navy… Between December and January until mid-
February, during the brisa period, the sea lions are
bought’ (J. M. confidential pers. comm. to C. Castro).
Although no evidence or assessment is presently
available regarding the use of FADs in artisanal fish-
ing operations in Ecuador, we suspect that both the
coastal gillnet fisheries and the large oceanic long-
line fisheries, targeting large pelagic fish such as
tuna, billfishes, and various shark species, may be
the main users of IFADs. This rationale is based on
the fact that the artisanal fisheries fleet usually oper-
ates within the 200 nautical miles (nm) of Ecuador’s
Economic Exclusive Zone (EEZ), including the coastal
multifilament gillnet fisheries and the oceanic arti-
sanal longline fisheries fleet (Alava et al. 2015,
Martínez-Ortiz et al. 2015). However, it is likely that
the artisanal fisheries fleet is currently expanding its
fishing operations beyond the 200 nm, specifically
the large oceanic artisanal longline fishery which is
unique to Ecuador and operates far offshore deploy-
ing a mothership with a fleet of small vessels (Alava
et al. 2015, Martínez-Ortiz et al. 2015). Assuming the
wide distribution of fishing zones and extension of
artisanal fishing fleet off Ecuador’s continental coast
as a proxy, we project that IFADs may also be used in
these fishing areas.
The overall scarcity of information begs for more
thorough fact-finding investigations that could then
serve as guidance to propose legislation that would
control or prohibit the use of marine mammals as
bait, search for alternatives and recommendations,
and establish exemplary sanctions. As it stands, the
deployment of FADs using marine mammals as bait
in Ecuador can have negative repercussions in the
face of new regulations established in 2017 under the
US Marine Mammal Protection Act (NMFS 2016),
commanding the implementation of a regulatory pro-
gram to monitor and mitigate marine mammals
bycatch in countries exporting seafood/fish to the
USA by 2022. Ecuador falls in this categoy as this
nation exports seafood to the USA but has not yet
implemented such a regulatory program (Jiménez et
al. 2018).
Since 2013, the IATTC, as the regional fisheries
management organization (RFMO) in the Eastern
Tropical Pacific, recommended the use of non-en -
tangling drifting FADs as a measure to mitigate the
entanglement and minimize deleterious damage to
susceptible marine fauna (Gershman et al. 2015,
Murua et al. 2016). Along with this measure, incen-
tives for marine observers and fishers should be
developed and fostered by local fisheries manage-
ment authorities, so as to record and retrieve aban-
doned, lost or discarded fishing gear, including de -
relict drifting FADs encountered at sea, and to
deliver the derelict fishing gear to port reception
facilities for recycling and disposal (Gilman 2015,
Gilman et al. 2016). The precautionary principle has
been emphasized as an approach to reduce, or at
least monitor and control, the use of dFADs to miti-
gate their adverse effects not only on yellowfin and
bigeye tuna stocks, sharks and sea turtles but also on
open-ocean ecosystems (Fonteneau et al. 2013). As
an option, the International Seafood Sustainability
Foundation has also recommended the use of non-
entangling biodegradable FADS, with minimal risk
of entanglement, constructed using only natural
and/or biodegradable materials (e.g. bamboo, sisal,
yute, palm leaves, coconut fiber, cotton) instead of
plastics and/or metals to further reduce and avoid the
environmental impact of marine pollution by drifting
FADs on the oceans (Murua et al. 2016, Moreno et al.
2016b). In October 2018, Ecuador’s Tuna Conserva-
tion Group launched a contest aimed at developing
bio degradable FADs (Eco-FADs) for industrial fish-
eries, especially tuna fishing in Ecuador to reduce
pollution (Tunacons 2019). Experiments by tuna pro-
cessing companies with certain bio degradable and
plant materials to test the designs are underway in
the country. Similar mitigation actions and incentives
should be promoted among small-scale (artisanal)
fishers by fisheries management authorities.
The issue of marine mammal-baited IFADs has
recently emerged as a threat to the conservation of
marine mammals in Ecuador and should be ad -
dressed. As estimated in this study, approximately a
fifth of dead marine mammals found stranded along
Ecuador’s beaches were associated with IFADs over
the period 2001 to 2017. If not addressed, within a
short period of time, illicit directed takes of both
cetaceans and pinnipeds could increase dramatically
and lead to severe conservation problems for
Ecuador’s marine mammal populations. Commu-
nity-based conservation including an open, bottom-
up dialogue is required urgently between Ecuador’s
artisanal fishing communities and fisheries manage-
Endang Species Res 41: 289– 302, 2020
ment actors assisted by experts. These should pro-
vide insights into the pervasiveness of IFAD use and
the origin of marine mammal-sourced bait, as well as
test and evaluate alternative bait (e.g. low-cost
frozen abattoir remains considered unfit for con-
sumption) and fully biodegradable IFAD materials.
Finally, these approaches can serve as potential
recommendations to deter and help pre vent the use
of marine mammals as bait.
Acknowledgements. This work is dedicated to the
memory of the late Gregory Kaufman, who was a great
colleague and devoted researcher from the Pacific Whale
Foundation. We thank the volunteers of the Pacific Whale
Foundation and park rangers, especially Johana Moreira
and Ruben Aleman, for their tenacity and dedication in
obtaining data. Ben Haase is acknowledged for confirming
Otaria byronia as the most frequent pinniped in Ecuador’s
continental waters, and Julio C. Reyes for providing a
helpful taxonomic opinion about some problematic photo-
graphs. Special thanks to Gregory Kaufman for providing
valuable insights and edits to an earlier version of this
manuscript. Alejandra Loaiza C. is thanked for preparing
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Editorial responsibility: Bryan P. Wallace,
Fort Collins, CO, USA
Submitted: September 3, 2019; Accepted: November 25, 2019
Proofs received from author(s): March 3, 2020
... regions. In some countries (e.g., Argentina), uses are rare events and are almost exclusively opportunistic, while in others (e.g., Peru and Ecuador), there is continued use of cetaceans in spite of existing legislation, especially as bait in a number of fisheries (Van Waerebeek and Reyes, 1994;Vidal et al., 1994;Van Waerebeek et al., 1999Avila et al., 2008;Crespo, 2009;Dawson, 2009;Flores and Da Silva, 2009;Goodall, 2009;Cosentino and Fisher, 2016;Campbell et al., 2020a,b;Castro et al., 2020). There are marked differences in the target species and methods used to capture them, both between and within countries. ...
... Recent data are scarce, but Sotalia guianensis has been confirmed as a target species Briceño et al., 2021). Recent studies in Ecuador have revealed the use of the CMS-listed Eastern Tropical Pacific (ETP) population of pantropical spotted dolphins as bait (Castro et al., 2020). In Ecuador, fishers use body parts of aquatic mammals, including dolphins, as bait in improvised Fish Aggregating Devices (FADs; Castro et al., 2020). ...
... Recent studies in Ecuador have revealed the use of the CMS-listed Eastern Tropical Pacific (ETP) population of pantropical spotted dolphins as bait (Castro et al., 2020). In Ecuador, fishers use body parts of aquatic mammals, including dolphins, as bait in improvised Fish Aggregating Devices (FADs; Castro et al., 2020). Several species are involved in this illegal practice, caught both accidentally and via direct targeting, but the extent of harvest is unknown. ...
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Wild animals are captured or taken opportunistically, and the meat, body parts, and/or eggs are consumed for local subsistence or used for traditional purposes to some extent across most of the world, particularly in the tropics and subtropics. The consumption of aquatic animals is widespread, in some places has been sustained for millennia, and can be an important source of nutrition, income, and cultural identity to communities. Yet, economic opportunities to exploit wildlife at higher levels have led to unsustainable exploitation of some species. In the literature, there has been limited focus on the exploitation of aquatic non-fish animals for food and other purposes. Understanding the scope and potential threat of aquatic wild meat exploitation is an important first step toward appropriate inclusion on the international policy and conservation management agenda. Here, we conduct a review of the literature, and present an overview of the contemporary use of aquatic megafauna (cetaceans, sirenians, chelonians, and crocodylians) in the global tropics and subtropics, for species listed on the Appendices of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). We find that consumption of aquatic megafauna is widespread in coastal regions, although to varying degrees, and that some species are likely to be at risk from overexploitation, particularly riverine megafauna. Finally, we provide recommendations for CMS in the context of the mandate of the Aquatic Wild Meat Working Group.
... There is only one record of the interaction of a bottlenose dolphin with longlines in the country (Félix et al., 2019). Nine cases of marine mammals used as bait in small-scale fish aggregation devices in a period of 11 years has been reported, although it is unknown how extended is this practice in the country (Castro et al., 2020). ...
... A similar conceptual misunderstanding can be found in Peruvian fisheries where the term 'bycatch' also typically refers to non-target or under-sized fish catch. The use of bycaught marine mammal carcasses as bait is well known in Peru (Campbell et al., 2020), and less extensive in Ecuador (Félix and Samaniego, 1994;Castro et al., 2020). The only way to reduce the trade in bycaught marine mammal carcasses is by enforcement against this illegal practice. ...
With the entry into force of the Fish and Fish Products Import Provisions of the United States Marine Mammal Protection Act (MMPA), countries that export such products to the U.S. market could face significant challenges. Provisions include that fish and fish products exported to the U.S. must come from fisheries with a regulatory program comparable in effectiveness to the U.S. standard. Using three countries in the Southeast Pacific (Chile, Ecuador and Peru) as a case study, the potential economic impacts of the MMPA were analyzed. As a reference, in 2019, this region exported 389 thousand tons valued at US $3.2 billion to the USA in fish and aquaculture products, of which ca. 69% could become subject to commercial restrictions related to the MMPA. In the case of Chile, most exported fish products come from aquaculture, but in Ecuador and Peru they come from small-scale fisheries. Because of the associated costs that countries may incur to comply with MMPA requirements, moving in stages is recommended, first issuing regulatory reforms related to marine mammals protection, and then estimating bycatch rates for each species/population by fishery. Simultaneously, but as a medium-term goal, population estimates to define limits of biological removal should be conducted. Despite the progress in fishing management made by these three countries, with Chile at the forefront, it may still be a challenge for the export fisheries to achieve comparability findings under the MMPA. However, efforts and incentives offer new opportunities for conservation by reducing current levels of marine mammal mortality in fisheries and is already having benefits that could be enhanced if countries address with responsibility the impacts from fisheries on marine mammals populations in the region.
... Significant catches of juvenile tunas, impacting the overall condition of the targeted stocks (Fonteneau, Pallares, and Pianet 2000;Leroy et al. 2013); Bycatch of endangered, threatened and protected (ETP) species such as sharks, turtles, rays, and others, which are incidentally caught in the process (Romanov 2002;Chanrachkij, Siriraksophon, and Loog-On 2009;Amand e et al. 2011;Gilman 2011;Filmalter et al. 2013;Gaertner et al. 2015;Moir Clark et al. 2015;Eddy, Brill, and Bernal 2016;Blasi, Roscioni, and Mattei 2016;Castro et al. 2020); Creating possible "ecological traps," or negative impacts to the distribution, migration, and reproductive ability of tuna stocks, as FADs attract tunas into habitats that provide less food or are otherwise less hospitable Hallier and Gaertner 2008); "Ghost fishing" by accidentally or deliberately abandoned FADs that have drifted too far away to be useful, the impacts of which are difficult to measure (Chanrachkij and Loog-On 2003;Smolowitz 1978) 2 ; Destruction of sensitive coral reefs and other sensitive habitats by drifting FADs (Zudaire et al. 2018); Marine pollution from FADs that have been lost, beached, or sunk (Moir Clark et al. 2015;Zudaire et al. 2018;Banks and Zaharia 2020;Sinopoli et al. 2020); and Unauthorized and unsupervised "fishing" as the FADs drift in and out of the Exclusive Economic Zones (EEZs) of Coastal States, Marine Protected Areas (MPAs), and/or areas "closed" to FADs by Regional Fisheries Management Organizations (RFMOs; Arias and Pressey 2016;Hanich et al. 2019). ...
... As noted above, a FAD is designed to "attract" fish and can be reasonably expected to do so (NOAA Fisheries 2020; MSC 2018; Dagorn and Freon 1999;FAO 2020). Webbing on a typical FAD "catches" or "takes" fish as bycatch and can be reasonably expected to do so (Romanov 2002;Chanrachkij, Siriraksophon, and Loog-On 2009;Amand e et al. 2011;Gilman 2011;Filmalter et al. 2013;Gaertner et al. 2015;Moir Clark et al. 2015;Eddy, Brill, and Bernal 2016;Blasi, Roscioni, and Mattei 2016;Castro et al. 2020). Satellite buoy locator signals are designed to "locate" fish and can reasonably be expected to do so (Zunzibal 2020). ...
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World tuna catches reached 5.2 million metric tons in 2018, more than doubling since the early 1990s, primarily due to the introduction of Fish Aggregating Devices (FADs). The widespread use of drifting FADs has increased the economic efficiency of the fleet by making it easier to aggregate and locate tuna schools, but at a high ecological cost, including: significant catches of juvenile tunas; bycatch of endangered, threatened and protected species; and "ghost fishing," marine pollution, and sensitive habitat destruction by abandoned FADs. Recent analysis indicates that most deployed FADs are eventually lost, stolen, beached, or abandoned, continuing their destructive impacts. This paper examines the legal regime, market forces, and other factors that frame FAD use. We demonstrate that, because deployed FADs are legally considered to be fishing, when they drift into closed areas or otherwise contravene national or international agreements or regulations, they are Illegal, Unreported, and/or Unregulated (IUU); vessels using such FADs are therefore IUU. We suggest that introducing a transparent FAD ownership tracking system and requiring FAD owners to mitigate their impacts could substantially improve the effectiveness of tuna Regional Fisheries Management Organizations (RFMOs) and redirect market incentives to properly support tuna management.
... In the Guapi-PNN Gorgona route, the economic impact for artisanal fishermen in 2008-2009 due to loss or damage to their fishing gear because of interaction with marine mammals was estimated at $7,700 USD for the whole community (Flórez-González & Capella, 2010). On the other hand, the practice of using marine mammals as bait in a FAD, as reported in the present study (i.e., whale calf of 29 November 2019; Figure 1e), had already been previously reported in Ecuador (Castro et al., 2020). ...
Humpback whale (Megaptera novaeangliae) is a migratory species that inhabits annually the waters of the Colombian Pacific for breeding. Accidental entanglement in fishing nets is a recurring threat to humpback whales globally. This study presents 14 recent cases (2016-2021) of accidental entanglements of humpback whales in the Colombian Pacific. Data was taken opportunistically during visits and stays in the area, and through information given from the local community and fishermen. We registered 14 entangled individuals, four of them were calves and 10 were adults. Most humpback entanglement cases involved surface gillnet gear, specifically trammel nets. Although these entanglement cases were sighted in Colombia, we cannot assure that these events occurred there, nor can we confirm whether the events occurred while fishing or in ghost-nets (ALDFG). Our results indicate that bycatch of humpback whales in Colombia has increased, and could be higher. This study highlights the importance of continuing monitoring whales and entanglements, and exalts the participation of the local community and environmental authorities as a primary source of information. In order to reduce this threat, it is recommended to move towards a fishery management that considers the migration times of whales and the use of technical methods to mitigate bycatch.
... Recent studies have highlighted the urgency of the issue. Marine mammals have been targeted for bait (Campbell et al., 2020;Briceno et al., 2021) or to attract fish to modified fish aggregating devices (Castro et al., 2020). ...
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Marine mammal interactions with fisheries, such as bycatch and depredation, are a common occurrence across commercial and small-scale fisheries. We conducted a systematic review to assess the management responses to marine mammal interactions with fisheries. We analyzed literature between 1995 and 2021 to measure research trends in studies on direct and indirect interactions for: (i) high and low to middle-income countries, (ii) fishery operations (commercial and small-scale), and (iii) taxonomic groups. Management responses were categorized using the framework described previously in peer-reviewed studies. Marine mammal bycatch remains a major conservation concern, followed by marine mammal depredation of fishing gear. A high proportion of studies concentrated on commercial fisheries in high-income countries, with an increase in small-scale fisheries in low to middle-income countries between 1999 and 2020. The insufficient understanding of the social dimensions of interactions and the inevitable uncertainties concerning animal and human behaviors are major challenges to effective management. Despite the key role of human behavior and socioeconomics, we found only eight articles that incorporate human dimensions in the management context. Integrating social dimensions of marine mammal interactions with fisheries could help in setting pragmatic conservation priorities based on enhanced understanding of critical knowledge gaps. An area-specific adaptive management framework could be an effective tool in reducing the risk to marine mammals from fisheries by coupling technical solutions with socio-economic and political interventions. We conclude that despite the vast body of literature on this subject, a “silver bullet” management solution to marine mammal interactions with fisheries does not yet exist.
... In contrast, the size of the catch with UNA type sets decreased over time, reaching its maximum catch value in 2009 with approximately 4,965 tons and the minimum in 2013 with only 97 tons of tuna (Figure 4).4 | DISCUSSIONThe greater spatial dispersion of FAD-type sets within the CMAR and their greater effectiveness compared to UNA-type sets may be due to the use of bait as a complementary factor to the aggregating devices, which greatly increases the likelihood of catching tunas(Varela et al., 2017) regardless of the position of the set. CFOP observers recorded that bait composition included mainly small pelagic species such as Auxis rochei, but whale parts, sea lions and dead turtles are also commonly used(Castro, Van Waerebeek, Cárdenas & Alava, 2020). The increased use of these devices in the CMAR coincides with the situation reported by the IATTC (2014) andFonteneau, Chassot & Bodin (2013), who indicated that the number of sets on aggregating devices increased by between 60 and 80% in the last 15 years. ...
• Fish aggregating devices (FADs) are floating objects that facilitate the aggregation of fish; those that aggregate pelagic species such as tunas are of particular interest for artisanal and industrial fisheries. • Due to the increasing use of these devices worldwide, bodies responsible for the administration and management of fishery resources have proposed control and surveillance activities focused on the use of such devices. To achieve this, it is essential to have access to quality information, which is usually obtained through on-board observer programmes such as the Colombian Fisheries Observer Program. • Based on the historical records of this programme, and for the first time, the spatial–temporal distribution of the FADs in the eastern tropical sector of the Eastern Pacific Ocean is presented, analysing 166 records of tuna fishing operations carried out between 2009 and 2015. Of the 2,328 sets identified in the records, 957 corresponded to sets on FADs, of which 80.56% were effective and caught 12,246 tons of tuna. • The number of sets of FADs increased over time, representing approximately 86.9% of the sets recorded in 2015, compared to 4.8% of this type of set recorded in 2009, with the Eastern Tropical Pacific Marine Corridor being the area of greatest concentration of sets. • Considering that the Eastern Tropical Pacific Marine Corridor was designed to promote the conservation and sustainable use of biological diversity in the Eastern Tropical Pacific, this study highlights the need to include as a research priority, the potential effect that aggregation devices may have on the biological connectivity processes present in the corridor, as well as on the dynamics of large pelagic fish populations of commercial interest. • In terms of management of FADs, it is recommended that a precautionary approach be adopted and that regulations related to the maximum number of FADs per vessel be adjusted according to their Inter-American Tropical Tuna Commission class, in addition to assigning a maximum number of sets per vessel.
... An additional layer of complexity is that, in at many cases, toothed whale catches in low-and middle-income nations may not even be considered as by-catch, rather they may often be of value for subsistence, as fishing bait, or for other traditional purposes (e.g. Castro et al. 2020;Porter et al. 2017). Lastly, gross domestic product is a powerful predictor of fisheries management and governance strength (Melnychuk et al. 2017). ...
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Fisheries by-catch poses the single greatest threat to cetacean (whales, dolphins and porpoises) populations. Despite this, by-catch of cetaceans does not receive proportionate levels of research or management effort. The contribution of small-scale fisheries to cetacean by-catch is generally overlooked because of the extreme data paucity in these fisheries. Here, we assess the likely geographic distribution of by-catch risk posed to the odontocetes (toothed whales) at the global scale. We combine species’ occurrence and estimates of fisheries susceptibility for all 72 marine toothed whale species with estimates of small-scale fisheries’ gillnet fishing pressure across 163 marine fishing nations. We show that the by-catch risk from small-scale fisheries is likely greatest in low- and middle-income regions, generally in the tropics and sub-tropics. Our findings highlight a “wicked problem”, that the highest by-catch risks primarily occur in regions with lowest fisheries management efficacy. Addressing by-catch in these priority regions is fraught with potentially damaging consequences for the survival of vulnerable human coastal communities. Yet, immediate management and conservation actions are required to prevent species extirpation and extinction through the reduction of small-scale fisheries by-catch. To be successful, these actions will likely require multilateral cooperation and must carefully balance both species and human needs.
... Despite their immense ecological value, marine ecosystems in the ETPO are becoming degraded due to the steady increase of anthropogenic pressures that can in some cases cause significant changes and reorganizations of the structure and function of marine ecosystems (Rocha et al., 2015). Climate change (Castrejón and Charles, 2020), illegal, unreported and unregulated (IUU) fishing (Castro et al., 2020), marine invasions (Carlton et al., 2019), pollution (Alava et al., 2014), increasing tourism, coastal development and population growth (Hastings et al., 2015;Ramirez, 2016) are among the well-documented problems posing a critical, growing threat to livelihoods, ecosystem sustainability and functioning of coastal zones. ...
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The San Jose Declaration formally established the Eastern Tropical Pacific Marine Corridor (CMAR) in 2004, a voluntary regional cooperation mechanism created by the coastal States of Ecuador, Costa Rica, Colombia, and Panama in response to anthropogenic pressures in the Eastern Tropical Pacific, one of the most productive and biodiverse oceans in the world. This article will explain how, in the absence of a coherent, overarching regional ocean governance framework, these four coastal States came together to create a regional cooperation mechanism for the conservation and sustainable use of marine biodiversity in the Eastern Tropical Pacific. The key normative features of CMAR will be examined, as well as legal and governance challenges, such as its non-binding nature, large scale, limited sectoral engagement, and insufficient resources. The analysis will be couched within a discussion of the wider regional ocean governance framework, which remains fragmented, with gaps and overlaps in terms of membership, mandates and geographic coverage. Possibilities for integration, and the potential impact of a new treaty protecting biodiversity beyond national jurisdiction (BBNJ), will also be considered.
... The use of marine mammals as bait is a geographically extensive activity, affecting at least 42 species in 33 countries, predominantly in Latin America, Asia and West Africa (Cosentino & Fisher 2016, Mintzer et al. 2018. Small cetaceans and pinnipeds are primarily used for shark, crab and lobster fisheries in the marine environment, and riverine dolphins are used for catfish fisheries in freshwater systems (Avila et al. 2008, Quintana-Rizzo 2014, Mintzer et al. 2018, Campbell et al. 2020, Castro et al. 2020. Marine mammals as bait are either (1) deliberately targeted, where animals are the main objective for fishers, (2) nontargeted-deliberate, bycaught or stranded animals are recovered and killed, and (3) non-targeted salvaged acquisition, when an incidentally caught animal is used (Hall 1996, Marsh et al. 2011, Robards & Reeves 2011. ...
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Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climate change, fisheries bycatch, pollution and maritime development, continue to impact many marine mammal species, and at least one-quarter are classified as threatened on the IUCN Red List. Conversely, some species have experienced population increases/recoveries in recent decades, reflecting management interventions, and are heralded as conservation successes. To continue these successes and reverse the downward trajectories of at-risk species, it is necessary to evaluate the threats faced by marine mammals and the conservation mechanisms available to address them. Additionally, there is a need to identify evidence-based priorities of both research and conservation needs across a range of settings and taxa. To that effect we: (1) outline the key threats to marine mammals and their impacts, identify the associated knowledge gaps and recommend actions needed, (2) discuss the merits and downfalls of established and emerging conservation mechanisms, (3) outline the application of research and monitoring techniques, and (4) highlight particular taxa/populations that are in urgent need of focus.
Species distribution models allow for the quantification of the species-environment relationship, with species of commercial interest being the most evaluated. To this group belong Thunnus albacares, Katsuwonus pelamis and Coryphaena hippurus, species that are the basis of different fisheries. These species are characterized by their global distribution and socio-economic benefits to countries. Therefore, it is convenient to analyze whether their distribution ranges and current environmental suitability areas could change with respect to the most extreme climate change scenario (RCP 8.5) projected for 2050 and 2100. To address this, presence records reported by the Colombian Fisheries Observation Program and the Global Biodiversity Information Facility, environmental information from Bio-ORACLE and the species distribution model assembly package BIOMOD 2 were used. Under current conditions, the highest suitability zone considers temperatures close to 27°C, salinities of 34 and current velocities of 0.1 m/s. This zone was located between 2 and 4 degrees north latitude, extending from the Colombia-Ecuador transboundary zone, approximately from 82 degrees west longitude to international waters, but was relocated south of the equator according to the RCP 8.5 climate change scenario projected to 2050 and 2100. The results of this study indicate that climate change would significantly affect the potential distribution of commercially important species in the Eastern Tropical Pacific in the future, making it necessary to implement adaptation plans to possible new environmental conditions, which could directly impact the economy and food security of communities that use these fisheries resources.
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Among anthropogenic threats to marine mammals, bycatch is one of the major and increasing concerns. This report describes three species of small cetaceans, including a short-beaked common dolphin (Delphinus delphis), a bottlenose dolphin (Tursiops truncatus), and two dwarf sperm whales (Kogia sima), which were found stranded with pectoral fins, dorsal fins and caudal fin removed. The dolphins were found at the beaches of San José de Las Nuñez and San Pablo, respectively (Santa Elena Peninsula Province on 14 August 2017), while the dwarf sperm whales were found in Puerto Lopéz and Crucita (Manabí Province) in July 2014 and August 2015, respectively. Possible explanation for the dolphins and dwarf sperm whales missing fins support the event as a possible case of fishery interaction or bycatch with systematic removal of their fins. Although remnants of artisanal gillnets were not found near the two dolphin species, one of the dwarf sperm whales showed marks of artisanal gillnets on the body as evidence of bycatch. Trade of dolphin carcasses and their parts for bait by fishers cannot be ruled out as there is some evidence of this practice in the past. Both dolphins species are vulnerable species at the national level and commonly involved in incidental captures with gillnets of artisanal fisheries in Coastal Ecuador. Cetacean bycatch is a grave conservation problem affecting several cetacean species in Ecuador’s waters. Fisheries and environmental authorities must be vigilant and enforce actions to proactively mitigate possible anthropogenic impacts and promote environmental education activities in fishing communities to conserve vulnerable dolphin species in Ecuador’s waters. Further, to comply with new rules and regulations of the US Marine Mammal Protection Act (MMPA) intended to reduce the bycatch of marine mammals in foreign commercial fishing operations that export fish and fish products to the United States, a regulatory program is urgently needed to mitigate and reduce fisheries interactions with marine mammals in Ecuador.
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Technical Report
The ecological and socioeconomic problems caused by abandoned, lost and discarded fishing gear (ALDFG) are increasingly of concern. Marine gillnets and trammel nets, which have relatively high ghost fishing potential, are globally important gear types. Used primarily by coastal, artisanal, small-scale fisheries worldwide, gillnet and trammel net fisheries supply about a fifth of global marine fisheries landings. The Food and Agriculture Organization of the United Nations and the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities, hosted by the United Nations Environment Programme, as Secretariat for the Global Partnership on Marine Litter, commissioned this study to identify best practices to estimate ghost fishing mortality rates and levels, priority research needs, and the status of international monitoring and management of ALDFG and ghost fishing by marine gillnet and trammel net fisheries. Accurate estimates of total ghost fishing mortality levels can be made given quality data on the density of ALDFG retaining fishing efficiency, duration of ghost fishing efficiency, and total ghost fishing mortality level of a unit-of-effort of ALDFG over the full period that the derelict gear retains fishing efficiency. Recommendations to improve estimates of regional and global rates and levels of ghost fishing from ALDFG from marine gillnet and trammel net fisheries were made. An assessment was made and opportunities were identified to improve intergovernmental organizations’ data collection protocols and management measures to prevent and remediate ALDFG and ghost fishing by marine gillnets and trammel nets.
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The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the "oceanic-artisanal" fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna-billfish-shark longline gear and the catch composition becomes much more diverse.
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The estimated total catch for the entire Santa Rosa fleet is 1150 (CI 95% 874-1426) dolphins/yr and that for the entire Puerto Lopez fleet is 156 (CI 95% 99-213). If the results are extrapolated to two similar ports nearby the estimated total bycatch is 3741 (CI 95% 2784-4698) dolphins caught in 1993. If similar capture rates apply to the rest of the country, the total national bycatch would be 2-3 times higher. By far the most frequently captured species was the common dolphin Delphinus delphis (86%) followed by the short-finned pilot whale Globicephala macrorrhychus(9%). -from Authors
Bycatch of marine fauna by small-scale (artisanal) fisheries is an important anthropogenic mortality source to several species of cetaceans, including humpback whales and odontocetes, in Ecuador's marine waters. Long-term monitoring actions and varied conservation efforts have been conducted by non-governmental organizations along the Ecuadorian coast, pointing toward the need for a concerted mitigation plan and actions to hamper cetaceans’ bycatch. Nevertheless, little has currently been done by the government and regional authorities to address marine mammal interactions with fisheries in eastern Pacific Ocean artisanal fisheries. This study provides a review of Ecuador's current status concerning cetacean bycatch, and explores the strengths and weaknesses of past and current programs aiming to tackle the challenges of bycatch mitigation. To bolster our appraisal of the policies, a synthesis of fishers’ perceptions of the bycatch problem is presented in concert with recommendations for fostering fishing community-based conservation practices integrated with policies to mitigate cetacean bycatch. Our appraisal, based upon the existing literature, indicates a situation of increasing urgency. Taking into consideration the fishers’ perceptions and attitudes, fisheries governance in Ecuador should draw inspiration from a truly bottom-up, participatory framework based on stakeholder engagement processes; if it is based on a top-down, regulatory approach, it is less likely to succeed. To carry out this process, a community-based conservation programs to provide conditions for empowering fishing communities is recommend. This would serve as an initial governance framework for fishery policy for conserving marine mammals while maximizing the economic benefits from sustainable small-scale fisheries in Ecuador.
An immense variety of fish may, on occasions, aggregate around or beassociated with floating structures such as drifting algae, jelliedzooplankton, whales, floats or anchored fish aggregating devices (ineffect, there are over 333 fish species belonging to 96 familiesrecorded in the literature). Several hypotheses have been advanced to explain this behaviour ofpelagic fish, although the most widely accepted theory is that fish usefloating materials, to some extent, to protect themselves frompredators. However, we think that aggregation under floats may be theresult of behaviour that has evolved to safeguard the survival of eggs,larvae and juvenile stages, during dispersion to other areas. Naturalfloating structures (e.g., algae, branches of trees) drift in seacurrents that originate in places where the floating objects arefrequently found (e.g., river estuaries, coastal areas). These same seacurrents also introduce some of the planktonic production generated inthese areas into the oligotrophic pelagic environment. Fish associatedwith drifting floating structures probably feed on invertebratesassociated with the structures. However, they may also benefit from theaccumulated plankton in the converging waters. Adult fish of somemigratory species (tuna, dolphinfish, etc.) have also developed similarassociative behaviour around drifting objects for other reasons (e.g.,resting places, presence of bait fish, geographical references andschool recomposition). In this context, the meeting point hypothesis isonly applicable to one specific case, the tuna and tuna-like species. Aggregative and associative behaviour, under and around floatingdevices, may be the result of convergent behaviors that result fromdifferent motivations. However, generally this behaviour can beexplained by the fact that drifting floating objects represent a meansof reaching relatively rich areas, where larvae and juvenile fish havean increased chance of survival.