scholarly journals Marine mammals used as bait for improvised fish aggregating devices in marine waters of Ecuador, eastern tropical Pacific

2020 ◽  
Vol 41 ◽  
pp. 289-302 ◽  
Author(s):  
C Castro ◽  
K Van Waerebeek ◽  
D Cárdenas ◽  
JJ Alava
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Tropical Pacific ◽  
South American ◽  
Physeter Macrocephalus ◽  
Eastern Tropical Pacific ◽  
Cetacean Species ◽  
Pilot Whale ◽  
Sea Lions ◽  
Fish Aggregating Devices

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 artisanal fishers in coastal Ecuador. At least 3 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, 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 novaeangliae 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 represented 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 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.

Recommendations for Sustainable Cetacean-Based Tourism in French Territories: A Review on the Industry and Current Management Actions

2020 ◽  
Vol 15 (3) ◽  
pp. 211-235
Author(s):  
Josephine Chazot ◽  
Ludovic Hoarau ◽  
Pamela Carzon ◽  
Jeanne Wagner ◽  
Stéphanie Sorby ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
French Polynesia ◽  
Legal Framework ◽  
Whale Watching ◽  
Cetacean Species ◽  
Commercial Activities ◽  
Management Actions ◽  
Overseas Territories ◽  
Socioeconomic Benefits

Whale-watching activities provide important socioeconomic benefits for local communities and constitute powerful platform incentives for marine mammals' protection or more broadly marine environments. However, these activities can cause adverse effects on targeted populations, with considerable downside associated risks of injuries and fatality for whale watchers during inwater interactions. France with its overseas territories has the second largest exclusive economic zone (EEZ), in which more than half of existing cetacean species are encountered. In these territories, recreational and commercial whale watching, including swim-with cetacean activities, have recently developed. Yet few studies focused on these activities and their associated impacts across French territories, leading to an unclear assessment of the situation. To address this issue, we reviewed cetaceans' occurrence within the French EEZ, whale-watching industry, targeted species, local management of marine mammal-based tourism activities, and regulations in France mainland and some overseas territories (Reunion Island, Mayotte, and French Polynesia). Fortyeight species are encountered in the French EEZ, and 15 are targeted by whale-watching activities. A total of 185 operators, including 34% offering swim-with-cetaceans tours, offered trips in France and overseas in 2019. While several more or less restrictive regulations exist locally, our results indicate that French's national legal framework for marine mammals' protection remains inadequate and insufficient to cope with the recent development of this activity. As conservation biologists, managers, and stakeholders from these French territories, we cooperated to provide general guidelines for a sustainable development of whale watching at a national scale. We urge (1) to legally acknowledge and regulate whale-watching commercial activities; (2) to create a national legal framework regarding whale watching and swim-with marine mammals practices, while accounting for local distinctiveness and disparities across regions; (3) to conduct more research to evaluate local short- and long-term impacts on targeted marine mammal populations as well as the socioeconomic benefits; and (4) to reinforce synergetic relations between the different stakeholders.

scholarly journals Cetacean Research and Citizen Science in Kenya

2021 ◽  
Vol 8 ◽  
Author(s):  
Michael Gilbert Mwango’mbe ◽  
Jane Spilsbury ◽  
Steve Trott ◽  
Judith Nyunja ◽  
Nina Wambiji ◽  
...  
Keyword(s):  
Citizen Science ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Conservation Strategies ◽  
Science Data ◽  
Pilot Whale ◽  
Area Of Interest ◽  
Mammal Conservation ◽  
Kenyan Coast

In 2011, several non-governmental and government agencies established the Kenya Marine Mammal Network (KMMN) to provide a platform for the consistent collection of data on marine mammals along the Kenyan coast, identify areas of importance and engage marine users and the general public in marine mammal conservation. Prior to the KMMN, relatively little was known about marine mammals in Kenya, limiting conservation strategies. The KMMN collects data nationwide through dedicated surveys, opportunistic sightings and participative citizen science, currently involving more than 100 contributors. This paper reviews data on sightings and strandings for small cetaceans in Kenya collated by the KMMN. From 2011 to 2019, 792 records of 11 species of small cetaceans were documented. The most frequently reported inshore species were the Indo-Pacific bottlenose dolphin and Indian Ocean humpback dolphin. Offshore species, included killer whales, short-finned pilot whale and long-snouted spinner dolphin. Indo-Pacific bottlenose dolphins, long-snouted spinner dolphins, striped dolphins and Risso’s dolphins were recorded through stranding reports. The efforts of the KMMN were disseminated through international meetings (International Whaling Commission, World Marine Mammal Conference), national status reports, outreach and social media. Data has also supported the identification of three IUCN Important Marine Mammal Areas and one Area of Interest in Kenya. Further research is needed to improve estimates of cetacean abundance and distribution, particularly in unstudied coastal areas, and to assess the extent of anthropogenic threats associated with fisheries, coastal and port development, seismic exercises and unregulated tourism. The expansion of the network should benefit from the participation of remote coastal fishing communities, government research agencies, tourism and seismic operations, among others. The KMMN demonstrated the value of dedicated and citizen science data to enhance marine mammal conservation strategies to boost awareness and eco-tourism and to bring the public and science closer together, promoting research and effective conservation efforts.

South American sea lions Otaria byronia as biological samplers of local cephalopod fauna in the Patagonian shelf marine ecosystem

2019 ◽  
Vol 99 (06) ◽  
pp. 1459-1463
Author(s):  
R. L. Bustos ◽  
G. A. Daneri ◽  
E. A. Varela ◽  
A. Harrington ◽  
A. V. Volpedo ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Marine Ecosystem ◽  
Isotopic Signature ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
South American ◽  
Sea Lions ◽  
Patagonian Shelf ◽  
Important Prey ◽  
Top Predators

AbstractCephalopods are important prey in the diet of top predators, such as marine mammals and seabirds. However, detailed information on their trophic relationships in the Patagonian marine ecosystem is scarce, including those cephalopod species with commercial interest. The aims of this study were to evaluate the composition of the cephalopod component in the diet of Otaria byronia and determine the habitat use and trophic levels of their main cephalopod prey by measuring the stable isotopic signature of cephalopod beaks. Between May 2005 and February 2009, fresh faecal samples were collected from two sea lions rookeries in San Matias Gulf. Cephalopods occurred in 39.4% of the 1112 samples collected during the whole period of study. The dominant prey species was Octopus tehuelchus, which occurred in 45.8% of scats containing cephalopod remains, and represented 58.7% in terms of numerical abundance and 52.0% in mass of cephalopods consumed. The second species most consumed was the myopsid Doryteuthis gahi. The significant higher δ15N values of O. tehuelchus beaks in comparison with those of D. gahi showed that these two species have different trophic levels while occupying similar habitat (δ13C values) in neritic waters of the Patagonian shelf.

scholarly journals Disconnects in global discourses—the unintended consequences of marine mammal protection on small-scale fishers

2020 ◽  
Author(s):  
Katrina J. Davis ◽  
Joanna Alfaro-Shigueto ◽  
William N.S. Arlidge ◽  
Michael Burton ◽  
Jeffrey C. Mangel ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Unintended Consequences ◽  
Small Scale ◽  
South American ◽  
Global Policy ◽  
Small Scale Fisheries ◽  
Gill Net ◽  
Large Scope ◽  
Mammal Conservation

AbstractGlobally, the populations of many marine mammals remain of critical concern after centuries of exploitation and hunting. However, some marine mammal populations (e.g. pinnipeds) have largely recovered from exploitation, and interactions between these species and fisheries—particularly small-scale fisheries—is once again of concern globally. The large scope and widespread scale of interactions highlights the local disconnect between two global policies: marine mammal conservation and small-scale fisheries protection. In this research, we explore these conflicting global policies by assessing the perceptions of coastal small-scale fishers in Peru and Chile regarding their interactions with pinnipeds, including the South American sea lion (Otaria flavescens) and South American fur seal (Arctocephalus australis). We surveyed 301 gill net fishers and assess perceptions using a best-worst scaling methodology. We find that fishers are chiefly concerned with the increase in pinniped populations, perceive that their interactions with pinnipeds have significantly increased over the past 80 years, and report pinniped-driven catch and income losses ≥ 26 per cent. Surprisingly, fishers do not believe that compensation schemes will resolve this issue—instead they overwhelmingly call for pinniped population culls. The reported number of pinnipeds illegally killed by fishers suggests the potential for large negative impacts on these protected species, and a loss of legitimacy in marine regulation. Collectively, our results portray a sense of marginalisation from fishers’—that global policy treats them as less “important” than marine mammals. Our results highlight the increasing disconnect in global policy, which on one hand seeks to protect threatened marine mammal populations, and on the other seeks to promote the welfare of small-scale fishers.

scholarly journals A review of marine mammal records of Cuba

2014 ◽  
Vol 9 (2) ◽  
pp. 65-122 ◽  
Author(s):  
Amy Danae Whitt ◽  
Thomas A. Jefferson ◽  
Miriam Blanco ◽  
Dagmar Fertl ◽  
Deanna Rees
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Cetacean Species ◽  
Baleen Whales ◽  
Common Bottlenose Dolphin ◽  
Extant Species ◽  
Pinniped Species ◽  
The Common ◽  
The Caribbean ◽  
West Indian Manatee

There has been very little research on marine mammals in Cuban waters. Much of the information on marine mammals in this region is buried in historical and gray literature. In order to provide a comprehensive account of marine mammal occurrence in Cuba’s Exclusive Economic Zone (EEZ), we reviewed and verified 659 published and unpublished sighting, stranding, capture, and tagging records. Eighteen extant species and four genera have confirmed records for Cuban EEZ waters. This includes 17 species of cetaceans (three baleen whales and 14 toothed whales) and one sirenian species. An additional 11 cetacean species and one extant pinniped species have been reported, but not confirmed, or may have the potential to occur in Cuban waters. Historical records of the Caribbean monk seal (Monachus tropicalis) are documented in Cuba; however, this species is now considered extinct. The only two species that are seen regularly and considered common in Cuban nearshore waters are the common bottlenose dolphin (Tursiops truncatus) and the West Indian manatee (Trichechus manatus).

Assessing host–parasite specificity through coprological analysis: a case study with species of Corynosoma (Acanthocephala: Polymorphidae) from marine mammals

2011 ◽  
Vol 86 (2) ◽  
pp. 156-164 ◽  
Author(s):  
F.J. Aznar ◽  
J. Hernández-Orts ◽  
A.A. Suárez ◽  
M. García-Varela ◽  
J.A. Raga ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Marine Mammals ◽  
Buenos Aires Province ◽  
South American ◽  
Sea Lions ◽  
South American Sea Lion ◽  
Parasite Specificity ◽  
Pontoporia Blainvillei ◽  
Host Parasite

AbstractIn this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. A total of 252 scats from the South American sea lion, Otaria flavescens, and rectal faeces from 43 franciscanas, Pontoporia blainvillei, from Buenos Aires Province, were examined for acanthocephalans. Specimens of two species, i.e. Corynosoma australe and C. cetaceum, were collected from both host species. In sea lions, 78 out of 145 (37.9%) females of C. australe were gravid and the sex ratio was strongly female-biased. However, none of the 168 females of C. cetaceum collected was gravid and the sex ratio was not female-biased. Conversely, in franciscanas, 14 out of 17 (82.4%) females of C. cetaceum were gravid, but none of 139 females of C. australe was, and the sex ratio of C. cetaceum, but not that of C. australe, was female-biased. In putative non-hosts, the size of worms was similar to that from specimens collected from prey. Results suggest that both acanthocephalans contact sea lions and franciscanas regularly. However, C. australe and C. cetaceum cannot apparently reproduce, nor even grow, in franciscanas and sea lions, respectively. Coprological analysis may represent a useful supplementary method to investigate parasite specificity, particularly when host carcasses are difficult to obtain.

The magnitude and sustainability of marine mammal by-catch in fisheries in East Malaysia

2008 ◽  
Vol 89 (5) ◽  
pp. 907-920 ◽  
Author(s):  
Saifullah A. Jaaman ◽  
Yuhana U. Lah-Anyi ◽  
Graham J. Pierce
Keyword(s):  
Marine Protected Areas ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Educational Programme ◽  
Cetacean Species ◽  
Spotted Dolphin ◽  
East Malaysia ◽  
By Catch ◽  
Catch Rates ◽  
Sabah And Sarawak

The magnitude and sustainability of incidental catches of marine mammals in fisheries was investigated in Sabah and Sarawak, East Malaysia, using a combination of interview surveys and observer trips on fishing boats. These fisheries involve around 15,000 registered fishing boats and generate annual landings of around 350,000 tonnes. Between March 1997 and December 2004, we interviewed fishermen working on 753 and 358 boats in Sabah and Sarawak, respectively, who were employing trawl nets, purse seines, gillnets and fish stakes. They were asked questions about sightings of marine mammals and interactions with fishing. We also followed 36 trawl and 10 purse seine fishing trips in Sabah between June 2003 and December 2004. Fishing was conducted in coastal waters and total annual catches by each method and region were estimated. Incidental catches of marine mammals were reported by fishermen from 310 (41%) and 99 (28%) fishing boats in Sabah and Sarawak, respectively. Gill-netters, trawlers and fish stakes were reported to catch cetaceans and dugongs, while purse seiners caught only cetaceans. The Irrawaddy dolphin, bottlenose dolphin, spinner dolphin, pantropical spotted dolphin, Indo-Pacific humpback dolphin and finless porpoise are the cetacean species known to be taken. Overall, the magnitude of incidental catches of marine mammals is greatest in gillnets. No marine mammal catches were seen during observer trips. Interview results suggest annual by-catches of 306 (95% CI = 250–369) cetaceans and 479 (95% CI = 434–528) dugongs in Sabah. Estimates for Sarawak were 221 (95% CI = 189–258) cetaceans per year and 14 (95% CI = 2–30) dugongs. These results suggest that by-catch rates, particularly in gillnets, may be unsustainably high. A dedicated monitoring and educational programme, together with the establishment of Marine Protected Areas, is urgently needed to minimize the threat.

Patterns of seabird and marine mammal carcass deposition along the central California coast, 1980–1986

1991 ◽  
Vol 69 (5) ◽  
pp. 1149-1155 ◽  
Author(s):  
James L. Bodkin ◽  
Ronald J. Jameson
Keyword(s):  
Cause Of Death ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Southern Oscillation ◽  
California Sea Lions ◽  
Central California ◽  
Sea Lions ◽  
Common Murres ◽  
Local Patterns ◽  
Species Specific

At monthly intervals from February 1980 through December 1986, a 14.5-km section of central California coastline was systematically surveyed for beach-cast carcasses of marine birds and mammals. Five hundred and fifty-four bird carcasses and 194 marine mammal carcasses were found. Common murres, western grebes, and Brandt's cormorants composed 45% of the bird total. California sea lions, sea otters, and harbor seals composed 90% of the mammal total. Several factors appeared to affect patterns of carcass deposition. The El Niño – Southern Oscillation (ENSO) of 1982–1983 was the dominant influence in terms of interannual variation in carcass deposition. During this ENSO, 56% of the seabirds and 48% of the marine mammals washed ashore. Patterns of intra-annual variation were species specific and were related to animal migration patterns, reproduction, and seasonal changes in weather. Nearshore currents and winds influenced the general area of carcass deposition, while beach substrate type and local patterns of sand deposition influenced the location of carcass deposition on a smaller spatial scale. Weekly surveys along a 1.1-km section of coastline indicated that 62% of bird carcasses and 41% of mammal carcasses remained on the beach less than 9 days. Cause of death was determined for only 8% of the carcasses. Oiling was the most common indication of cause of death in birds (6%). Neonates composed 8% of all mammal carcasses.

Metabolic rates of seals and whales

1986 ◽  
Vol 64 (2) ◽  
pp. 279-284 ◽  
Author(s):  
D. M. Lavigne ◽  
S. Innes ◽  
G. A. J. Worthy ◽  
K. M. Kovacs ◽  
O. J. Schmitz ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Food Consumption ◽  
Marine Mammal ◽  
Critical Review ◽  
Comparative Studies ◽  
Marine Mammals ◽  
Metabolic Rates ◽  
Sea Lions ◽  
Terrestrial Mammals ◽  
Fur Seals

A critical review of metabolic rate determinations for pinnipeds (seals, sea lions, fur seals, and walrus) and cetaceans (whales, dolphins, and porpoises) does not support the widely accepted generalization that they have higher metabolic rates than terrestrial mammals of similar size. This finding necessitates a rethinking of the thermoregulatory adaptations of these marine mammals for an aquatic existence and has important implications in comparative studies of mammals, which frequently omit marine forms because they are perceived to be "different" from other mammals. It also suggests that numerous studies have overestimated food consumption by marine mammal populations.

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