scholarly journals Cetacean community off French Guiana

Author(s):  
Claire Pusineri ◽  
Ludivine Martinez ◽  
Amandine Bordin ◽  
Benjamin De Montgolfier ◽  
Ophélie Deffes ◽  
...  

Although human activities are developing in French Guiana Exclusive Economic Zone (EEZ) and surrounding countries, knowledge on diversity and ecology of cetaceans in the region is scarce. This study aimed to collect new information on the cetacean species occurring year-round in the entire French Guiana EEZ by combining visual and acoustic data obtained from three boat-based campaigns conducted by local NGOs. The GEPOG campaign was conducted from July 2011 to June 2012, four days every two months; the COHABYS campaign was performed five days per month from January to May 2018; the OSL campaign consisted in four 10-day surveys conducted in June, July, September and October 2018. The visual observation effort conducted when Beaufort sea state < 5 was 1,961 km, 1,491 km and 3,243 km respectively. Acoustic records were done when Beaufort sea state < 5 during daylight and/or nighttime, depending on the survey. A total of 132 cetacean sightings were done. Five cetacean families and 15 species were identified. Delphinidae was the family most frequently sighted (91% to 100% of groups and 99% to 100% of individuals per campaign). The most frequent species in the area were identified, along with their distribution and phenology: Guiana dolphin (Sotalia guianensis) was found in the coastal area (0-20 m), the long-beaked common dolphin (Delphinus delphis) was sighted on the shelf (20-100 m), along with the bottlenose dolphin (Tursiops truncatus) and the Atlantic spotted dolphin (Stenella frontalis) that were also common on the upper slope (100-1,500 m). Finally, the spinner dolphin (Stenella longirostris), the melon-headed whale (Peponocephala electra) and the pantropical spotted dolphin (Stenella attenuata) were frequent on the slope (100-3,500 m). The results suggest these species may be found in French Guiana waters all year round and mother and calf pairs, as indicator of reproduction, were observed for all of them except the long-beaked common dolphin and the Guiana dolphin. Mother and calf pairs of humpback whales (Megaptera novaeangliae), that potentially belong to the “A” stock, were also sighted twice, as well as two groups of sperm whales (Physeter macrocephalus) with calves. Hence, these results showed that French Guiana bears a particular responsibility for the conservation of cetacean biodiversity, but a lot remains to be done to strengthen knowledge and conservation of these species in the territory.

2013 ◽  
Vol 94 (6) ◽  
pp. 1161-1174 ◽  
Author(s):  
Jolanda A. Luksenburg

Aruba is one of the most densely populated islands in the Caribbean. However, very little is known about its cetaceans. In 2010 and 2011, a total of 19721 km (1686 h) boat-based surveys over nearshore transects resulted in 117 positively-identified sightings comprising eight species. New records are also added for one of three previously-documented species. Five additional species were documented from strandings or reports by others. This brings the total number of cetacean species identified in Aruban waters to 16, of which nine are authenticated here for the first time. Atlantic spotted dolphin (Stenella frontalis (N = 59) and bottlenose dolphin (Tursiops truncatus) (N = 33) were the most frequently observed species, with sightings of both year-round, followed by spinner dolphin (S. longirostris) and false killer whale (Pseudorca crassidens). Additional species recorded are pantropical spotted dolphin (S. attenuata), striped dolphin (S. coeruleoalba), common dolphin (Delphinus capensis), rough-toothed dolphin (Steno bredanensis), short-finned pilot whale (Globicephala macrorhynchus), killer whale (Orcinus orca), Risso's dolphin (Grampus griseus), humpback whale (Megaptera novaeangliae), Bryde's/Eden's whale (Balaenoptera brydei/edeni), sperm whale (Physeter macrocephalus) and an unidentified beaked whale (Mesoplodon sp.). All cetaceans were sighted within 22 km of the coast in relatively shallow waters. Sighting rate was low (0.69 cetacean sightings per 100 km). Sightings of calves and neonates indicate that Aruba may be a nursing or breeding area for some species. The presence of several species of cetaceans in Aruba's coastal waters year-round indicates that status and threat assessments are needed to protect them.


2015 ◽  
Vol 10 (1) ◽  
pp. 2-19 ◽  
Author(s):  
Marijke Nita De Boer

Very little information exists about the cetaceans in the Guianas: Suriname and its neighboring countries Guyana and French Guiana. During a dedicated cetacean survey carried out from a geophysical seismic survey vessel in the offshore waters of Suriname (May-September 2012), the occurrence of 13 cetacean species was documented and of those, 11 were newly documented for this area. The species observed by the author included sperm whale (Physeter macrocephalus), Bryde’s whale (Balaenoptera edeni), false killer whale (Pseudorca crassidens), melon-headed whale (Peponocephala electra), roughtoothed dolphin (Steno bredanensis), long-beaked common dolphin (Delphinus capensis), Fraser’s dolphin (Lagenodelphis hosei), pantropical spotted dolphin (Stenella attenuata) and spinner dolphin (Stenella longirostris). During transit to the survey area (Trinidad to Suriname) incidental sightings were recorded which included common bottlenose dolphin (Tursiops truncatus) off Trinidad, Stenella sp. off Guyana and Guiana dolphin (Sotalia guianensis) at the entrance of the Suriname River. Opportunistic records originating from the periods December 2008-March 2009 and August-October 2012 were forwarded to the author. These records included common bottlenose dolphin, Atlantic spotted dolphin (Stenella frontalis) and short-finned pilot whale (Globicephala macrorhynchus). There is a growing need to identify critical areas for marine biodiversity conservation, both locally and regionally. This paper describes the general occurrence of the cetacean community encountered in Suriname waters in summer. The study revealed that the offshore cetacean community in Suriname is best described as primarily a tropical community, dominated by odontocetes (dolphins and sperm whales). Although the species diversity was relatively high, the overall cetacean relative abundance index (number of animals per 100km effort) was low, which is consistent for tropical equatorial offshore waters. Apart from the sperm whale and the Guiana dolphin, all the other species recorded represent new species records for Suriname. It is recommended that more continuous monitoring in different seasons be carried out in order to gain a better understanding of the occurrence, distribution and status of the different cetacean species within the region. 


1999 ◽  
pp. 177-194
Author(s):  
John Henry

Concentrations of zinc, copper, cadmium, mercury and lead were measured by atomic absorption spectrophotometry in samples of the brain, kidney , liver and muscle tissue from 178 individuals of 323 different cetacean species (4 right whales - Eubalaena australis, 2 pygmy right whales - Caperea marginara, 3 minke whales - Balaenoptera acutorostrata, 3 Bryde's whales - B. edeni, 1 humpback whale - Megaptera novaeangliae, 1 sperm whale - Physeter macrocephalus, 11 pygmy sperm whale - Kogia breviceps, 6 dwarf sperm whales - K. simus, 1 southern bottlenose whale - Hyperoodon planifrons, 1 Cuvier's beaked whale - Ziphius cavirostris, 9 Blainville's beaked whales - Mesoplodon densirostris, 5 strap-tooth whales - M. layardii, 2 True's beaked whales - M. mirus, 3 long-finned pilot whales - Globicephala me/as, 30 Risso's dolphins - Grampus griseus, 12 bottlenose dolphins - Tursiops truncatus, 5 striped dolphins - Stenella coeruleoalba, 1 pantropical spotted dolphin - S. attenuata, 1 hump-backed dolphin - Sousa chinensis, 21 dusky dolphins - Lagenorhynchus obscurus, 1 hourglass dolphin - L. cruciger, 12 Heaviside's dolphins - Cephalorhynchus heavisidii and 43 common dolphins - Delphinus delphis). All but the hourglass dolphin were strandings or animals taken incidental to fishing operations or under scientific permit in coastal waters of South Africa or Namibia. Highest concentrations of Zn, Cu and Hg were generally found in the liver and of Cd in the kidney. Comparisons of animals pre-and post puberty indicated accumulation of hepatic mercury in the pygmy sperm whale, Risso's dolphin, dusky dolphin and common dolphin. Loss of a metal (zinc) after puberty was only shown in the common dolphin. No individual analyses exceeded proposed (human) tolerance limits for hepatic mercury and hepatic or renal cadmium


2020 ◽  
Vol 642 ◽  
pp. 227-240
Author(s):  
L Lodi ◽  
R Tardin ◽  
G Maricato

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.


2020 ◽  
Vol 11 ◽  
Author(s):  
Deanna Leonard ◽  
Nils Øien

A ship-based mosaic survey of Northeast Atlantic cetaceans was conducted over a 5-year period between 2014–2018. The area surveyed extends from the North Sea in the south (southern boundary at 53oN), to the ice edge of the Barents Sea and the Greenland Sea. Survey vessels were equipped with 2 independent observer platforms that detected whales in passing mode and applied tracking procedures for the target species, common minke whales (Balaenoptera acutorostrata acutorostrata). Here we present abundance estimates for all non-target species for which there were sufficient sightings. We estimate the abundance of fin whales (Balaenoptera physalus) to be 11,387 (CV=0.17, 95% CI: 8,072–16,063), of humpback whales (Megaptera novaeangliae) to be 10,708 (CV=0.38, 95% CI: 4,906–23,370), of sperm whales (Physeter macrocephalus) to be 5,704 (CV=0.26, 95% CI: 3,374–9,643), of killer whales (Orcinus orca) to be 15,056 (CV=0.29, 95% CI: 8,423–26,914), of harbour porpoises (Phocoena phocoena) to be 255,929 (CV=0.20, 95% CI: 172,742–379,175), dolphins of genus Lagenorhynchus to be 192,767 (CV=0.25, 95% CI: 114,033–325,863), and finally of northern bottlenose whales (Hyperoodon ampullatus) to be 7,800 (CV=0.28, 95% CI: 4,373–13,913). Additionally, our survey effort in the Norwegian Sea in 2015 contributed to the 6th North Atlantic Sightings Survey (NASS) and the survey was extended into the waters north and east of Iceland around Jan Mayen island. This NASS extension, along with our Norwegian Sea survey in 2015, was used to estimate the abundance of fin whales, humpback whales, and sperm whales. All estimates presented used mark-recapture distance sampling techniques and were thus corrected for perception bias. Our estimates do not account for additional variance due to distributional shifts between years or biases due to availability or responsive movement.


Author(s):  
Marcos R. Rossi-Santos ◽  
Elitieri Santos-Neto ◽  
Clarêncio G. Baracho

The large majority of cetacean interspecific studies report only on dolphin interactions, while studies on interactions between odontocete and mysticete are less common. The present work aims to report on sightings of cetacean interactions, during the breeding season of humpback whales(Megaptera novaeangliae), along 370 km of the Bahia State, north-eastern Brazil, addressing aspects of cetacean distribution and behaviour. During 7 seasons (2000–2006), a total of 230 research cruises were performed, in which 38 events of interactions among humpback whales and other cetaceans(Tursiops truncatus, Steno bredanensis, Peponocephala electraandBalaenoptera acutorostrata)were observed, plus another 5 encounters without the whale's presence, includingT. truncatus, S. bredanensis, P. electra, Stenella clymeneandStenella attenuata. Our results confirm the occurrence of multiple cetacean species in the Bahia State, being the first study in the world to report on a large range of interactions involving another 4 cetacean species, grouped with up to 3 mixed species per sighting, with humpback whales in their annual breeding ground.


2010 ◽  
Vol 58 (2) ◽  
pp. 123-142 ◽  
Author(s):  
Marcos César de Oliveira Santos ◽  
Salvatore Siciliano ◽  
André Fabiano de Castro Vicente ◽  
Fernando Siqueira Alvarenga ◽  
Émerson Zampirolli ◽  
...  

The São Paulo state (SP) coast (23º18'S, 44º42'W; 25º14'S, 48º01'W) is of approximately 600 km in length, bordering the Western Atlantic Ocean, in southeastern Brazil. Cetacean sightings and strandings have long been observed throughout this area. Scattered data from scientific publications, skeletal remains in museums, photographs and articles from newspaper files, universities and aquaria have been organised and updated since 1993. Field investigations on strandings and sightings have also been conducted. A total of 29 cetacean species have been recorded, including 7 baleen whales (Mysticeti) and 22 toothed whales (Odontoceti), as follows: Balaenoptera physalus, B. borealis, B. edeni, B. acutorostrata, B. bonaerensis, Megaptera novaeangliae, Eubalaena australis, Physeter macrocephalus, Kogia breviceps, K. sima, Berardius arnuxii, Mesoplodon europaeus, M. mirus, Ziphius cavirostris, Orcinus orca, Feresa attenuata, Globicephala melas, G. macrorhynchus, Pseudorca crassidens, Delphinus capensis, Lagenodelphis hosei, Steno bredanensis, Tursiops truncatus, Stenella frontalis, S. longirostris, S. coeruleoalba, Lissodelphis peronii, Sotalia guianensis and Pontoporia blainvillei. Several species have been observed only once and include strays from their areas of common distribution, as well as species with known preferences for offshore distribution. Others, such as P. blainvillei and S. guianensis, are common coastal dwellers year-round. Z. cavirostris, P. crassidens and L. hosei are reported for the first time on the SP coast.


2020 ◽  
Vol 11 ◽  
Author(s):  
Daniel G. Pike ◽  
Thorvaldur Gunnlaugsson ◽  
Bjarni Mikkelsen ◽  
Sverrir Daniel Halldórsson ◽  
Gísli Víkingsson ◽  
...  

The Trans-North Atlantic Sightings Survey (T-NASS) carried out in June-July 2007 was the fifth in a series of large-scale cetacean surveys conducted previously in 1987, 1989, 1995 and 2001. The core survey area covered an area of about 1.8 million nm² spanning from the Eastern Barents Sea at 34°E to the east coast of Canada, and between 52°N and 78°N in the east and south to 42°N in the west. We present design-based abundance estimates from the Faroese and Icelandic vessel survey components of T-NASS, as well as results from ancillary vessels which covered adjoining areas. The 4 dedicated survey vessels used a Buckland-Turnock (B-T) mode with a tracker platform searching an area ahead of the primary platform and tracking sightings to provide data for bias correction. Both uncorrected estimates, using the combined non-duplicate sightings from both platforms, and mark-recapture estimates, correcting estimates from the primary platform for bias due to perception and availability, are presented for those species with a sufficient number of sightings. Corrected estimates for the core survey area are as follows: fin whales (Balaenoptera physalus): 30,777 (CV=0.19); humpback whales (Megaptera novaeangliae): 18,105 (CV=0.43); sperm whales (Physeter macrocephalus): 12,268 (CV=0.33);  long-finned pilot whales (Globicephala melas): 87,417 (CV=0.38); white-beaked dolphins (Lagenorhynchus albirostris): 91,277 (CV=0.53); and white-sided dolphins (L. acutus): 81,008 (CV=0.54). Uncorrected estimates only were possible for common minke whales (B. acutorstrata): 12,427 (CV=0.27); and sei whales (B. borealis): 5,159 (CV=0.47). Sighting rates from the ancillary vessels, which used a single platform, were lower than those from the dedicated vessels in areas where they overlapped. No evidence of responsive movement by any species was detected, but there was some indication that distance measurements by the primary platform may have been negatively biased. The significance of this for the abundance estimates is discussed. The relative merits of B-T over other survey modes are discussed and recommendations for future surveys are provided.


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