Cetacean Diversity Research Articles

A fossil sperm whale (Cetacea, Physeteroidea) from the Pleistocene of Nauru, equatorial southwest Pacific

Several Recent cetacean species have a near-cosmopolitan dis tribution in the open-ocean, with some taxa rarely venturing near shore (Rice, 1998; Jefferson et al, 2008). In contrast, the fossil record of Cet cea is primarily derived from continental shelf sequences (Fordyce and Muizon, 2001). Rare exceptions to this bias include fragmentary fossils dredged from abyssal plains (Turner, 1880; Eastman, 1903; Roux and Geistdoerfer, 1988), and, rarer still, those from oceanic islands (Estevens and vila, 2007). These sources of fossil Cet cea are important because they have the potential to (1) sample fossil cetacean diversity from otherwise poorly represented oceanic paleoenvironments; and (2) add insights into the past zoogeography and ecology of cetaceans that may not be apparent from neritic shelf assem blages. A significant limitation on the last point is the gener ally poor stratigraphic control associated with dredged cetacean fossils (Bianucci et al., 2007). With such uncertain stratigraphic contexts, the broader significance of open-ocean fossil Cet cea is problematic. Although fossil cetaceans from oceanic islands may be associated with more evidence on geologic age, such de posits have hitherto proved extremely rare: late Miocene-early Pliocene fossils on the Azores in the mid-North Atlantic repre sent the sole pre-Holocene record of Cet cea from oceanic is lands (Estevens and Avila, 2007). The Pacific has been the largest ocean throughout cetacean history and its Rim has produced an excellent fossil record (Fordyce, 2008). Yet until now, none of its ~20,000 oceanic islands (i.e., on oceanic crust) have yielded pre Holocene Cet cea. This note reports the first discovery of a pre-Holocene cetacean from a Pacific oceanic island-a stem physeteroid from the Pleistocene of Nauru, represented by an isolated tooth (NMV P204274) (Figs. 1-2). This new fossil evidence adds to knowl edge of both the spatial and temporal distribution of stem Phy seteroidea.

Response to Comment on “Climate, Critters, and Cetaceans: Cenozoic Drivers of the Evolution of Modern Whales”

Pyenson et al . raise concerns about the correlation we identified between diatom and cetacean diversity through time. Although the issues raised are of investigative interest, they do not invalidate our conclusions. We agree that localized studies combined with global data sets will further our understanding of the factors that have helped shape cetacean evolution.

Cetacean diversity and distribution off Tenerife (Canary Islands)

Dedicated surveys were conducted along the south-west and north-east coasts of Tenerife (Canary Islands), between 1997 and 2006, to gather baseline information on cetacean diversity, abundance, spatial and temporal distribution. A total of 1016 sightings of sixteen cetacean species was recorded during the study period. Sightings were recorded throughout the year although the period in which the highest number of species were sighted was in spring and summer (from May through to August). The most frequently sighted species were bottlenose dolphin (Tursiops truncatus) and short-finned pilot whale (Globicephala macrorhynchus), which together comprised 82% of the total sightings. These were followed by common dolphin (Delphinus delphis), Atlantic spotted dolphin (Stenella frontalis) and dense beaked whale (Mesoplodon densirostris) which represented 9% of the total sightings. Most sightings were recorded along the south-west coast of Tenerife, where the distribution of the different species seemed to be influenced by water depth. Calves were present during sightings of almost every recorded species, especially in toothed whales. Two mother–calf pairs of fin whales (Balaenoptera physalus) were also observed. This suggests that the surveyed area, or at least the south-west sub-area, might play an important role as a calving ground for the four most frequently sighted species. The information acquired in this study indicates that the waters around Tenerife constitute an important habitat for cetaceans.

Cetacean distribution and relative abundance in offshore Gabonese waters

Information on cetaceans off Gabon in tropical West Africa is summarized from boat-based surveys carried out between 7 March and 7 August 2009. Thirteen cetacean species were positively identified comprising two baleen whale species, one sperm whale species and ten species of delphinid. Bryde's whale (Balaenoptera brydei) and humpback whale (Megaptera novaeangliae) were the most frequently encountered species. Cetaceans were found throughout a range of sea surface temperature between 20.5°C and 27.5°C and a wide range of depths with the majority of effort and sightings occurring seaward of the shelf break. Of particular interest from the study were the following: (1) Gabonese waters have a broad cetacean diversity, especially with a large and diversified delphinid community in the northern part of the study area; (2) the variations in oceanographic conditions within Gabonese waters are likely to result in a temporal variation in species composition; (3) the sightings of Atlantic spotted dolphin (Stenella frontalis) are the first at-sea sightings confirmed for these waters, although not unexpected given their distribution and abundant presence in surrounding waters; and (4) the poorly known Clymene dolphin (Stenella clymene) was sighted on four occasions in deep oceanic waters and was the most abundant cetacean. These are the first confirmed records of Clymene dolphins in Gabonese waters.

Diversity of deep-water cetaceans and primary productivity

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 408:1-5 (2010) - DOI: https://doi.org/10.3354/meps08619 FEATURE ARTICLE Diversity of deep-water cetaceans and primary productivity Hal Whitehead*, Kristin O’Brien, Boris Worm Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada *Email: hwhitehe@dal.ca ABSTRACT: Recently, it has been suggested that mammal diversity both on land and in the sea is controlled by patterns of primary productivity. Here we tested the hypotheses that large-scale patterns of marine mammal diversity are linked to primary productivity, sea surface temperature (SST) or a combination of these 2 factors. We used a consistently sampled sightings database of deep-water cetaceans in the Atlantic and Pacific Oceans, along with in situ SST measurements and 3 satellite-derived productivity measures matched spatially and temporally to available sightings. Cetacean genus richness peaked in regions of high primary productivity (>1000 to 1500 mg C m–2 d–1), but most of this effect is captured by optimal SST in those same regions. Our results show that the best-supported, explanatory models of cetacean diversity included SST, while the addition of satellite-derived measures of productivity did not improve predictive capacity. Marine mammal richness globally peaks around 40°N and S, and may result more directly from optimal SST at these latitudes rather than high oceanic productivity. KEY WORDS: Biodiversity · Productivity · Sea surface temperature · Cetacean Full text in pdf format Information about this Feature Article NextCite this article as: Whitehead H, O’Brien K, Worm B (2010) Diversity of deep-water cetaceans and primary productivity. Mar Ecol Prog Ser 408:1-5. https://doi.org/10.3354/meps08619 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 408. Online publication date: June 03, 2010 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2010 Inter-Research.

Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile

AbstractViddi, F. A., Hucke-Gaete, R., Torres-Florez, J. P., and Ribeiro, S. 2010. Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile. – ICES Journal of Marine Science, 67: 959–970. Compared with other Chilean coastal areas, little is known about the diversity and distribution of cetaceans in northern Patagonian fjords. Between December 2000 and November 2001, surveys on platforms of opportunity were undertaken in southern Chile to evaluate species richness and the spatial and seasonal distribution of cetaceans. Nine species were recorded, blue, humpback, and minke whales, Peale's dolphin, Chilean dolphin, killer whale, false killer whale, bottlenose dolphin, and Cuvier's beaked whale. The pattern of cetacean distribution displayed significant seasonal differences, with most baleen whales (mysticetes) observed during late summer and autumn, and toothed cetaceans (odontocetes) mostly during spring. Generalized additive models, used to assess the spatial distribution of cetaceans, showed that mysticetes were distributed disproportionately along a north–south gradient, in open gulfs with oceanic influence, and close to shore. In contrast, odontocetes were observed mainly within narrow channels, areas with complex coastal morphology, peaking at different water depths. These findings, although from a single year of data, increase our understanding of habitat determinants of cetacean distribution in southern Chile. The results have the potential to be applied to coastal conservation and management in the region.

Preliminary account of cetacean diversity and humpback whale (Megaptera novaeangliae) group characteristics around the Union of the Comoros (Mozambique Channel)

Abstract Cetacean diversity and occurrence has never been investigated in the Union of the Comoros, located in the northern Mozambique Channel. Small boat-based surveys were conducted during the austral winter of 2002, primarily to assess the occurrence of humpback whales (Megaptera novaeangliae) and whether the area represents a wintering ground where the species reproduce. All other cetacean species were also recorded. Opportunistic sighting records were used to provide information on the diversity of cetaceans occurring in the area. Between 2000 and 2003, 12 cetacean species were recorded around the Comoros, including: Megaptera novaeangliae, Stenella longirostris, Peponocephala electra, Stenella attenuata, Tursiops truncatus, Globicephala macrorhynchus, Mesoplodon densirostris, Physeter macrocephalus, Lagenodelphis hosei, Grampus griseus, Mesoplodon pacificus and possibly Tursiops aduncus. During the dedicated surveys, the humpback whale was the most commonly encountered species (72% of sightings) followed by the spinner dolphin (15%). Humpback whale group composition was heterogeneous, but mother-calf pairs were the most commonly sighted (49%). This study demonstrates that the Union of the Comoros is an important site for migrating humpback whales in the southwest Indian Ocean and for a wide variety of toothed cetacean species.

Serological Diagnosis of Brucella Infections in Odontocetes

Brucella ceti causes disease in Odontoceti. The absence of control serum collections and the diversity of cetaceans have hampered the standardization of serological tests for the diagnosis of cetacean brucellosis. Without a "gold" standard for sensitivity and specificity determination, an alternative approach was followed. We designed an indirect enzyme-linked immunosorbent assay (iELISA) that recognizes immunoglobulins G (IgGs) from 17 odontocete species as a single group. For the standardization, we used Brucella melitensis and Brucella abortus lipopolysaccharides, serum samples from seven resident odontocetes with no history of infectious disease displaying negative rose bengal test (RBT) reactions, and serum samples from seven dolphins infected with B. ceti. We compared the performance of the iELISA with those of the protein G ELISA (gELISA), the competitive ELISA (cELISA), and the immunofluorescence (IF) and dot blot (DB) tests, using 179 odontocete serum samples and RBT as the reference. The diagnostic potential based on sensitivity and specificity of the iELISA was superior to that of gELISA and cELISA. The correlation and agreement between the iELISA and the gELISA were relatively good (R(i/g)2 = 0.65 and kappa(i/g) = 0.66, respectively), while the correlation and agreement of these two ELISAs with cELISA were low (R(i/c)2 = 0.46, R(g/c)2 = 0.37 and kappa(i/c) = 0.62, kappa(g/c) = 0.42). In spite of using the same anti-odontocete IgG antibody, the iELISA was more specific than were the IF and DB tests. An association between high antibody titers and the presence of neurological symptoms in dolphins was observed. The prediction is that iELISA based on broadly cross-reacting anti-dolphin IgG antibody would be a reliable test for the diagnosis of brucellosis in odontocetes, including families not covered in this study.

Cetacean Diversity, Distribution, and Abundance in Northern Veracruz, Mexico

Cetacean Diversity, Distribution, and Abundance in Northern Veracruz, Mexico

Diversity of deep‐water cetaceans in relation to temperature: implications for ocean warming

Understanding the effects of natural environmental variation on biodiversity can help predict response to future anthropogenic change. Here we analyse a large, long-term data set of sightings of deep-water cetaceans from the Atlantic, Pacific and Indian Oceans. Seasonal and geographic changes in the diversity of these genera are well predicted by a convex function of sea-surface temperature peaking at c. 21 degrees C. Thus, diversity is highest at intermediate latitudes - an emerging general pattern for the pelagic ocean. When applied to a range of Intergovernmental Panel on Climate Change global change scenarios, the predicted response is a decline of cetacean diversity across the tropics and increases at higher latitudes. This suggests that deep-water oceanic communities that dominate > 60% of the planet's surface may reorganize in response to ocean warming, with low-latitude losses of diversity and resilience.

Cetacean diversity at the west coast of La Palma Island (Canary Islands)

Little is known about cetacean communities around La Palma Island. Therefore, and in order to determine the presence and distribution of the cetacean species on its west coast, daily censuses were carried out from November 2003 to April 2005. The platform used was a whale watching vessel certified by the Canary Government. Data collected included time, position, species identity, group size and, in some cases, the presence of calves and/or any other outstanding parameter. During the study period, 570 sightings were made, with a mean sighting success of 1.7 sightings per day, showing a high cetacean presence in the area. Thirteen species and one genus (Globicephalaspp.) were positively matched, three of them included in the Mysticeti suborder and the other ten in the Odontoceti one. The four most sighted species, in decreasing order, correspond toTursiops truncatus,Steno bredanensis,Globicephalaspp. andStenella frontalis. Diversity of sighted species shows a moderate peak during spring time, which is in agreement with the presence of occasional species. Most sightings were located off the central west coast of the island, exceeding 1.5 nautical miles. This is particularly outstanding in relation to Franja Marina de Fuencaliente SCI, where 90% of all sightings were located outside its boundaries. High cetacean presence and diversity off the west coast of La Palma Island seem to be connected with oceanographic and ecological features. Results gained provide, for this region, baseline data on cetacean populations and a useful tool in conservation plans.

Cetacean diversity on the Parnaiba Delta, Maranhão state, northeastern Brazil

The increase in the research of cetacean surveys on the Brazilian coast has brought new data on the distribution of species never reported before. The present work reviews the current knowledge on cetaceans species and extends this knowledge with an analysis of cetaceans stranded in the Parnaiba Delta, on the coast of Maranhão State, Brazil. The studies on cetacean diversity on the coast of the Parnaíba Delta were made from August 2004 to August 2006. Fourteen strandings were reported, representing six distinct species, such as the estuarine dolphin (Sotalia guianensis), humpback whale (Megaptera novaeangliae), Bryde's whales (Balaenoptera edeni), dwarf minke whale (Balaenoptera acutorostrata), pigmy killer whale (Feresa attenuata), sperm whale (Physeter macrocephalus) and two specimens which have not yet been identified. The significant degree of cetacean diversity in the region shows that the Parnaíba Delta is, possibly, of an important area for cetacean studies in Brasil.

Cetacean diversity off La Réunion Island (France)

The waters of La Réunion, a French island located in the south-western Indian Ocean, have never been investigated for cetacean diversity. Dedicated daily surveys were conducted in 2004–2007 to assess cetacean diversity off the western and southern coasts of the island. A total of ten species was observed during the survey period, including two baleen whales and eight odontocetes. Four additional species that had not been observed at sea were reported stranded. The most frequent delphinid species were the Indo-Pacific bottlenose, the spinner and the common bottlenose dolphins, which were observed year-round. Photo-identification data showed a high recapture rate ofTursiops aduncus, strongly suggesting a resident population. The humpback whale uses the coastal waters of La Réunion seasonally, during winter. The high proportion of mother–calf pairs indicated that La Réunion might represent a breeding area for this species. Pantropical spotted dolphin, melon-headed whale and Fraser's dolphin were sighted at a medium frequency, in offshore waters, and tended to favour the southern part of the island. Three coastal species were frequently using the newly created Marine Protected Area (MPA), supporting the view that cetacean conservation issues have to be included in the MPA management plan currently in progress.

Pilot cetacean survey of the sub-Arctic North Atlantic utilizing a cruise-ship platform

Using a large passenger cruise-ship (MV ‘Discovery’) as a platform, a cetacean survey was conducted between 1 August and 3 September 2005 across the northern North Atlantic Ocean and back, covering waters between the UK, Iceland, Greenland and Canada. The objective was to collect sightings data for all cetacean species encountered to begin to collate information for a large-scale sightings database. Two observers employed standard-distance sampling techniques and visual observations (naked eye) to scan for cetaceans during daylight hours and favourable weather conditions. Approximately 112 h were spent surveying over 23 d. A total of 13 cetacean species were encountered, with 173 separate sightings recorded, totalling over 2000 animals. The most commonly sighted species were minke whales (Balaenoptera acutorostrata: N=44), Atlantic white-sided dolphins (Lagenorhynchus acutus: N=34, with group sizes of up to 600), and humpback whales (Megaptera novaeangliae: N=31). The distribution of minke whales, Atlantic white-sided dolphins and fin whales was linked to underlying oceanographic variables. Overall patterns of distribution were consistent with our understanding of the summer distributions for the species encountered. The survey highlighted the cetacean diversity of the northern North Atlantic region. Repeat work using this methodology will allow an examination of species' distributions and estimation of their relative abundance.

Diversity of cetaceans as tool in monitoring environmental impacts of seismic surveys

New information about the effects of seismic surveys on cetaceans is causing increasing concern about the impact of this type of activity on marine life. The effects described include behavioral responses and changes in vocalization patterns, diversion of migratory routes, damage to the auditory system, and an increase in strandings. Although such effects could affect the diversity of species in areas where seismic research has been carried out, there is no scientific information on this subject. This study aims to evaluate the relationship between seismic surveys, oceanographic data and diversity of cetaceans recorded in Brazil following the stepping up of seismic survey activities between 1999 and 2004. The study is based on oceanographic data from the Pilot Research Moored Array in the Tropical Atlantic (PIRATA Project), sightings made during seismic surveys, progress reports from Brazilian research projects to the International Whaling Commission, Brazilian seismic survey reports available at the Escritório de Licenciamento de Petróleo e Nuclear of the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (ELPN-Ibama) and complementary data from the webpage of the Agencia Nacional de Petróleo e Gás Natural (ANP). The results suggest a decrease in the diversity of species in the face of an increase in the number of seismic surveys during the years 2000 and 2001, even though there was no significant change in oceanographic patterns in this period, and that a relationship exists between diversity of cetaceans and intensity of seismic surveys between 1999 and 2004. It is recommended that data collection be improved in order to evaluate this hypothesis properly. The results suggest that species diversity might be used as a long-term indicator of the impact of seismic surveys on cetaceans.

A survey of public awareness of the occurrence and diversity of cetaceans in south-west Scotland

In summer 2001, members of the public in south-west Scotland were interviewed to determine their knowledge of the diversity and occurrence of cetaceans in the region. Interviews were conducted in both rural island and coastal communities and a major city.The majority of interviewees (46%) underestimated the number of cetacean species occurring in western Scottish waters (i.e. <10 species). Only 4·4% gave the correct answer (24). Location of the participant affected the level of knowledge. Photographs were presented of the four most commonly occurring cetacean species: only 30·2% correctly identified one or more of the species. The species most frequently identified correctly was the bottlenose dolphin (19% of interviewees) followed by the harbour porpoise (17·5%), minke whale (10·7%) and, lastly, the common dolphin (7·1%).Interviewees were also asked whether certain cetacean species occurred in local waters or not. The level of awareness was generally low. The most common positive answers involved the bottlenose dolphin, harbour porpoise, and minke whale. Only one in five were aware of killer whales and 13·1% believed that grey whales occurred in Scottish waters. Knowledge of species occurrence showed statistically significant relationships with age, gender, level of environmental interest and location, but not occupation (teachers, tourism professionals and marine stakeholders did not show greater levels of cetacean knowledge). The study identified target groups and locations where knowledge of cetaceans is low and environmental education efforts should be concentrated.

Spatial and temporal changes in the cetacean community structure at Bahía de La paz, BCS, México (1988-1991)

At two different ecological zones (Canal de San Lorenzo and transitional), located at Bahía de La Paz, we analysed changes in the cetacean community (Shannon and Simpson indexes) in relation to annual and seasonal changes in sea surface temperature, water transparency and inferred and reported food availability. Six odontocete and six mysticete species were recorded during the study period. Due to their high relative abundance and persistent presence, the long beak common (Delphinus capensis) and bottlenose (Tursiops truncatus) dolphins, as well as Bryde’s whales (Balaenoptera edeni) were, respectively, the most important odontocete and mysticete community members. The evidente indicates that sea surface temperature and water transparency, besides food availability, show predictable seasonal and annual changes related to the influence of tropical water masses and to large scale oceanographic phenomena, such as El Niño Southern Oscillation and La Niña. Nevertheless, cetacean diversity did not show consequent changes. The cetacean community was more diverse and stable at the transition between seasonal and annual oceanographic conditions. Cetacean diversity changed significantly at smaller time and space scales, defined by the interaction of particular annual, seasonal and local conditions. This and changes in species richness, mediated by the temporal residence of migrating species of temperate waters or more sporadic tropical visitors, indicate the existence of fast and important changes in species abundance and substitution rates, associated with the behavioural ecology of the species and fluctuations in the ecosystem’s metabolism.