Diversity, relative density and structure of the cetacean community in summer months east of Great Abaco, Bahamas

Little is known about cetacean communities in the tropical and sub-tropical Atlantic. This paper describes the cetacean community found east of Great Abaco in the northern Bahamas (26·5°N) during summer months between 1998 and 2001. Nine species of cetaceans were recorded, which could be divided into two distinct groupings: firstly, ‘permanent’ species, which had relative sightings rates between 0·026–0·084 sightings per hour and which were recorded on many occasions in all years and most months; secondly, ‘sporadic’ species, which had relative sightings rates an order of magnitude lower (0·004–0·008 sightings per hour) and which were recorded on very few occasions. The ‘permanent’ species were the Stenella frontalis (Atlantic spotted dolphin), Kogia simus (the dwarf sperm whale), Mesoplodon densirostris (Blainville's beaked whale) and Ziphius cavirostris (Cuvier's beaked whale). These four species differed significantly in the depth of grid squares utilized (χ=20·25, df=9, P<0·01) suggesting that these species occupied four separate niches. Stenella frontalis dominated the surface feeding niche, while the remaining three deep-diving species segregated into different depth ranges. Kogia simus was the dominant species in water depths of less than 200 m, M. densirostris in water depths of 200 to 1000 m and Z. cavirostris in water depths of greater than 1000 m. The overall relative density (2·533 individuals per hour of effort) and diversity of species in the study area was relatively low and may relate to low levels of local productivity. It is hypothesized that the four ‘permanent’ species may competitively exclude ecologically similar species, resulting in a reduced number of species and that ‘sporadic’ species may only enter the study area during times of higher than usual productivity when the ‘permanent’ species are no longer able to dominate their individual niches.

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Prey Fields and Habitat of Deep Diving Odontocetes: 3D Characterization and Modeling of Beaked and Sperm Whale Foraging Areas in the Tongue of the Ocean

10.21236/ada573676 ◽

2012 ◽

Author(s):

Douglas P. Nowacek ◽

Louis St. Laurent ◽

David J. Moretti ◽

Patrick N. Halpin

Keyword(s):

Sperm Whale ◽

Deep Diving

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Cetacean strandings along the Pacific and Caribbean coasts of Nicaragua from 2014 to 2021

Marine Biodiversity Records ◽

10.1186/s41200-021-00209-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Joëlle De Weerdt ◽

Eric Angel Ramos ◽

Etienne Pouplard ◽

Marc Kochzius ◽

Phillip Clapham

Keyword(s):

Marine Mammals ◽

Sperm Whale ◽

Distribution Patterns ◽

Sperm Whales ◽

The Pacific ◽

Toothed Whale ◽

Beaked Whales ◽

Causes Of Mortality ◽

Cuvier’S Beaked Whale ◽

Stenella Attenuata

AbstractDocumenting marine mammal strandings provides important information needed to understand the occurrence and distribution patterns of species. Here, we report on strandings of cetaceans on the Pacific (n = 11) and Caribbean (n = 2) coasts of Nicaragua, documented opportunistically from 2014 to 2021. Strandings included three species of baleen whale (blue whale Balaenoptera musculus, Bryde’s whale Balaenoptera edeni, humpback whale Megaptera novaeangliae) and five species of toothed whale (dwarf sperm whale Kogia sima, Guiana dolphin Sotalia guianensis, pantropical spotted dolphin Stenella attenuata, spinner dolphin Stenella longirostris, Cuvier’s beaked whale Ziphius cavirostris). These are the first published accounts of blue whales, Bryde’s whales, dwarf sperm whales, and Cuvier’s beaked whales in Nicaraguan waters. Limited resources and the advanced decomposition of animals prevented necropsies in most cases, the identification of the causes of mortality in all cases, and the species identification of two dolphins. Information derived from these stranding events offers new insights into the occurrence of marine mammals on the Pacific and Caribbean coasts of Nicaragua and Central America.

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Antimicrobial Activity of Lactococcus lactis subsp. lactis Isolated from a Stranded Cuvier’s Beaked Whale (Ziphius cavirostris) against Gram-Positive and -Negative Bacteria

Microorganisms ◽

10.3390/microorganisms9020243 ◽

2021 ◽

Vol 9 (2) ◽

pp. 243

Author(s):

Akihiko Suzuki ◽

Miwa Suzuki

Keyword(s):

Lactococcus Lactis ◽

Marine Organism ◽

Growth Conditions ◽

Gas Production ◽

Beaked Whale ◽

Carbohydrate Utilization ◽

Nisin Z ◽

Ziphius Cavirostris ◽

Cuvier’S Beaked Whale ◽

Subtilis Subsp

In the present study, we isolated and characterized Lactococcus lactis (L. lactis) subsp. lactis from a female Cuvier’s beaked whale (Ziphius cavirostris) stranded in Shizuoka, Japan. Only five isolates (CBW1-5), grown on Lactobacilli de Man Rogosa Sharpe (MRS) agar plates prepared using 50% artificial seawater, were positive in L. lactis species-specific primer PCR. Their 16S rRNA sequences were highly similar to those of L. lactis subsp. lactis JCM 5805T. The Gram reaction, motility, gas production from glucose, catalase production, and growth conditions were consistent with those of the type strain. Additionally, carbohydrate utilization of the strains was consistent with previously reported marine organism-derived strains. The pH-neutralized cell-free culture supernatant of strain CBW2 inhibited the growth of Bacillus subtilis subsp. subtilis ATCC 6051 and Vibrio alginolyticus ATCC 17749, whereas protease treatment eliminated or diminished its inhibitory activity. The strain possesses a precursor of the nisin structural gene (nisA), which showed 100% homology with nisin Z, and nisin biosynthesis-related genes (nisB, nisC, nisT, nisP, nisF, nisI, and nisRK), suggesting that the strain produces a nisin-like substance. This study provides fundamental information on whale-derived L. lactis subsp. lactis which may be useful for reducing the carriage of B. subtilis subsp. subtilis and V. alginolyticus.

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Deep-diving beaked whales dive together but forage apart

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1905 ◽

2021 ◽

Vol 288 (1942) ◽

pp. 20201905

Author(s):

Jesús Alcázar-Treviño ◽

Mark Johnson ◽

Patricia Arranz ◽

Victoria E. Warren ◽

Carlos J. Pérez-González ◽

...

Keyword(s):

Beaked Whale ◽

Acoustic Interference ◽

Deep Diving ◽

Trade Offs ◽

Group Competition ◽

Foraging Performance ◽

Cooperative Foraging ◽

Beaked Whales ◽

Group Members ◽

Benefits And Costs

Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigate these potential trade-offs of sociality for extreme deep-diving Blainville′s and Cuvier's beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We show that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enables whales to coordinate their mean travel direction despite differing individual headings as they pursue prey on a minute-by-minute basis. While beaked whales coordinate their echolocation-based foraging periods tightly, individual click and buzz rates are both independent of the number of whales in the group. Thus, their foraging performance is not affected by intra-group competition or interference from group members, and they do not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We conclude that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance.

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Modeling the acoustic repertoire of Cuvier's beaked whale clicks

The Journal of the Acoustical Society of America ◽

10.1121/10.0001266 ◽

2020 ◽

Vol 147 (5) ◽

pp. 3605-3612

Author(s):

Thomas Guilment ◽

Natalia Sidorovskaia ◽

Kun Li

Keyword(s):

Beaked Whale ◽

Cuvier’S Beaked Whale

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Comparison of Novel Conductive Open- and Closed-Porous PPy-PLA Composites

Volume 1: Active Materials, Mechanics and Behavior; Modeling, Simulation and Control ◽

10.1115/smasis2009-1312 ◽

2009 ◽

Author(s):

Christine Chan ◽

Ellen Chan ◽

Weijia Zhang ◽

Hani E. Naguib

Keyword(s):

Relative Density ◽

In Situ Polymerization ◽

Compression Molding ◽

Salt Leaching ◽

Conductive Composites ◽

Order Of Magnitude ◽

Density Values ◽

Average Size ◽

Porous Composites

This study compared the fabrication techniques and characterization of novel open- and closed-porous structures in PPy-PLA conductive composites. For the open-porous composites, PLA samples were fabricated using compression molding and salt leaching with varying salt-to-polymer mass ratios, which were subsequently coated with PPy by in situ polymerization of pyrrole and iron (III) chloride. For the closed-porous composites, a patterned structure of PPy within PLA was created using compression molding of PPy-coated PLA pellets, followed by gas saturation and foaming techniques in order to create the closed pores. Characterization of both porous composites included their physical, mechanical, and electrical properties. Results showed that the modulus increased with increasing relative density and decreasing open porosity. The open-porous composites had lower relative density values but higher open porosities compared to the closed-porous composites. The average size of the closed pores was approximately an order of magnitude larger than the open pores. Lastly, the open-porous composites had higher conductivity values than the closed-porous composites due to the greater surface area of the continuous conductive pathway. The comparisons between open- and closed-porous composites established their characteristic properties for their future development in applications.

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