Articles on this page are available in 2 other languages: Spanish (2), Dutch (1) (learn more)

Overview

Brief Summary

Atlantic white-sided dolphins are true vagabonds. They never stay long in one place. They live in the northeastern Atlantic Ocean, sometimes in large schools. A school usually contains adults and young. They are often joined by white-beaked dolphins. White-sided dolphins are rapid hunters, preying mostly on squid and small fish.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Copyright Ecomare

Source: Ecomare

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Biology

This species is a very social and active animal; it forms groups of up to several hundred individuals (5), and tends to readily mix with other species of cetaceans (whales and dolphins) (4). This fast-swimming species can often be seen breaching (clearing the water), bow-riding (riding on the bow-wave at the front of boats and even large whales), and splashing the tail flukes noisily onto the surface of the water (4). They feed on a range of fish species as well as squid (2). Strandings of both individuals and of groups are a fairly common occurrence (4). A single calf is typically produced in June or July after a gestation period of around ten months (7). At birth the calf measures somewhere in the region of 1.1 metres in length (2), and will be weaned by 18 months of age (7).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Description

The Atlantic white-sided dolphin is a large, robust species (4), which is easily recognised by the obvious yellow patch towards the rear of the flanks (2). The common name refers to the pale band on each side situated below the dorsal fin (2). This species is often confused with the white-beaked dolphin, but the Atlantic white-sided dolphin has a much darker back (5). It may also be confused with the common dolphin because of the similar pattern (grey, white, black and yellow), but it lacks the distinctive hourglass pattern (6).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Description

Like other species of the genus Lagenorhynchus, the Atlantic white-sided dolphin is a stocky animal with a short, thick snout. It is common in cold North Atlantic waters. Most of what we know about its natural history has been learned by studying the carcasses involved in mass strandings, which can involve a hundred or more animals. Studies of stranded cetaceans are an important way to learn about these animals, and these events are carefully documented. Between 1968 and 1993, 348 Atlantic white-sided dolphins were stranded along the New England coast. From them, biologists have estimated growth and reproductive patterns, and have documented some of the foods they eat, which include a variety of fish and squid.

Links:
Mammal Species of the World
  • Original description: Gray, 1828, Spicil. Zool., 1:2
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution

Source: Smithsonian's North American Mammals

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comprehensive Description

Description

 The Atlantic white-sided dolphin Lagenorhynchus acutus reaches up to 2.8 m in length. It has moderately long and slender flippers and small tail flukes. The dorsal fin is tall, large and located on the middle of the back. The head is smoothly sloping with a distinct but small snout. It has a complex clearly demarcated colour pattern. It is black to dark grey on the back from the upper beak to the tail, changing sharply to light grey on the sides. The lower jaw and belly, as far as the anus, are white. A distinct white band is visible on the flanks under the dorsal fin between the black and light grey colouration, which turns into an olive-yellow stripe towards the rear at the lower margin of the dark dorsal colouration. A dark line runs from the upper beak to, and surrounding, the eye.Atlantic white-sided dolphins are usually found in large pods of up to several thousand individuals. Mixed schools with other species including white-beaked dolphins, Lagenorhynchus albirostris, have been recorded. Their surface behaviour is typical of dolphins with acrobatic leaps but bow-riding uncommon. Dive duration is unknown (Kinze, 2002).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

©  The Marine Biological Association of the United Kingdom

Source: Marine Life Information Network

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

Northern East and West Atlantic Ocean
  • North-West Atlantic Ocean species (NWARMS)
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Range Description

Atlantic white-sided dolphins are found in cold temperate to subpolar waters of the North Atlantic, from about 38°N (south of Cape Cod) in the west and the Brittany coast of France in the east, north to southern Greenland, Iceland, and southern Svalbard (Reeves et al. 1999; Cipriano 2002). The range includes the U.K. and the northern coasts of Scandinavia, although they rarely enter the Baltic Sea. They also sometimes move quite far up the Saint Lawrence River of eastern Canada, and they have been seen as far south as Strait of Gibraltar (Hashmi and Adloff 1991, 1992).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Geographic Range

The distribution of the Atlantic white-sided dolphin is the cool temperate and subartic waters of the north Atlantic Ocean from southern Greenland to Massachusetts, and from the British Isles to western Norway. It has also been reported as far as the sourthern Barents Sea, the Baltic Sea, the Azores, and the Adriatic Sea.

Biogeographic Regions: atlantic ocean (Native )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

occurs (regularly, as a native taxon) in multiple nations

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Global Range: Cooler temperate waters of the North Atlantic. Off the northeastern U.S. and southeastern Canada, most abundant apparently in the Gulf of Maine (Gaskin 1992).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Northern North Atlantic
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Range

This species inhabits cool temperate and sub-arctic waters of the North Atlantic (4). In UK waters, main concentrations occur around the Hebrides, the Northern Isles and northern areas of the North Sea (3). It is sometimes seen off the west of Ireland, and in the south-west approaches of the English Channel (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Physical Description

Morphology

Physical Description

Lagenorhynchus acutus ranges from 2.5 to 3 meters in length. The pectoral fin is about 30 cm in length and the dorsal fin may be up to 50 cm in height. The tail flukes range from 30 to 60 cm across. Females may be considerably smaller than males and average only 182 kg.

The dorsal region of L. acutus is black, while its sides are gray. The ventral regions are white from the lower jaw to just past the anus. Within the gray sides are yellowish white patches, which are probably its most distinct characteristic (Minasian et al., 1984). Black rings around the eyes are also present. The dorsal fin is tall, sharply curved and pointed at the tip, giving the species the name acutus or, Latin for "sharp". Lagenorhynchus acutus has a stocky body with sickle shaped fins and a thick tail stock. The beak is prominent with 30 to 40 pairs of pointed teeth.

Range mass: 180 to 250 kg.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

  • Minasian, S., K. Balcomb, L. Foster. 1984. The World's Whales. Washington, D. C.: Smithsonian Books.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Size

Length: 2700 cm

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Male maximum length 2.75 m., female max. length 2.43 m.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Size in North America

Sexual Dimorphism: Males are slightly larger than females.

Length:
Range: 2.3-2.8 m males; 1.9-2.4 m females

Weight:
Range: 180-230 kg
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution

Source: Smithsonian's North American Mammals

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Diagnostic Description

Morphology

Distinguishing characteristics: colour black with yellow and white patches on side and white belly. Dives without lifting tail. Blow not readily visible. Curved dorsal fin. Small beak.
  • North-West Atlantic Ocean species (NWARMS)
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Type Information

Type for Lagenorhynchus acutus (Gray, 1828)
Catalog Number: USNM 12306
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Female;
Preparation: Cast; Model; Photograph
Collector(s): United States Fish Commission
Year Collected: 1874
Locality: Portland, Cumberland, Maine, United States, North America, North Atlantic Ocean
  • Type: Cope, E. D. 1876. Proc. Acad. Nat. Sci. Philadelphia. 28: 136.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Syntype for Lagenorhynchus acutus (Gray, 1828)
Catalog Number: USNM 12939
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Female;
Preparation: Cast; Mounted Skeleton
Collector(s): V. Edwards
Year Collected: 1874
Locality: Cape Cod, Barnstable, Massachusetts, United States, North America, North Atlantic Ocean
  • Syntype: Cope, E. D. 1876. Proc. Acad. Nat. Sci. Philadelphia. 28: 136.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Syntype for Lagenorhynchus acutus (Gray, 1828)
Catalog Number: USNM A14228
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Unknown;
Preparation: Partial Skull
Collector(s): V. Edwards
Year Collected: 1874
Locality: Cape Cod, Barnstable, Massachusetts, United States, North America, North Atlantic Ocean
  • Syntype: Cope, E. D. 1876. Proc. Acad. Nat. Sci. Philadelphia. 28: 136.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

inshore to mainly offshore
  • North-West Atlantic Ocean species (NWARMS)
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

cold temperate to subpolar, mostly in deep water
  • UNESCO-IOC Register of Marine Organisms
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Habitat and Ecology

Habitat and Ecology
The Atlantic white-sided dolphin is found primarily in waters of the continental shelf and slope, but it also occurs in oceanic waters across the North Atlantic. Along the continental slope of North America, it seems to associate with high sea-bed relief along the continental shelf (Palka et al. 1997).

These dolphins often associate and feed with large baleen whales (fin and humpback whales), and are known to form mixed groups with pilot whales and a number of other dolphin species (including bottlenose and white-beaked dolphins). Atlantic white-sided dolphins feed mostly on small schooling fish (such as herring, mackerel, cod, smelt, hake, and sandlance), shrimp, and squid.

Systems
  • Marine
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Lagenorhynchus acutus is typically found in cool pelagic waters, where its major predators are killer whales and sharks. Since it usually prefers the open water, L. acutus is not commonly seen from shore. It mostly occupies waters of 40 to 270 m in depth around the continental shelf. L. acutus seems to prefer a surface temperature between 6 to 20 degrees Celsius and areas with low salinity.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Depth range based on 2010 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1620 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 0.625 - 21.559
  Nitrate (umol/L): 0.147 - 10.275
  Salinity (PPS): 30.771 - 36.658
  Oxygen (ml/l): 5.138 - 8.121
  Phosphate (umol/l): 0.054 - 0.762
  Silicate (umol/l): 0.494 - 5.416

Graphical representation

Temperature range (°C): 0.625 - 21.559

Nitrate (umol/L): 0.147 - 10.275

Salinity (PPS): 30.771 - 36.658

Oxygen (ml/l): 5.138 - 8.121

Phosphate (umol/l): 0.054 - 0.762

Silicate (umol/l): 0.494 - 5.416
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Habitat Type: Marine

Comments: Mainly continental shelf waters; most abundant in areas of steepest subsurface topographic relief; mean water depth for U.S. sightings was 165 m (Gaskin 1992). Inhabits offshore waters. Occurs where water temperature is 1-15 C, mainly less than 12 C (IUCN 1991).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

 The Atlantic white-sided dolphin is an oceanic species prefering deep waters on the outer continental shelf and slope.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

©  The Marine Biological Association of the United Kingdom

Source: Marine Life Information Network

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Temperate marine waters.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

The Atlantic white-sided dolphin tends to prefer depths of between 40 and 270 metres in the vicinity of the continental shelf where the surface temperature is in the range of 6 to 20 degrees Celsius (5). It seems to prefer areas with high seabed relief, and along the continental shelf (6).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Stellwagen Bank Pelagic Community

 

The species associated with this page are major players in the pelagic ecosystem of the Stellwagen Bank National Marine Sanctuary. Stellwagen Bank is an undersea gravel and sand deposit stretching between Cape Cod and Cape Ann off the coast of Massachussets. Protected since 1993 as the region’s first National Marine Sanctuary, the bank is known primarily for whale-watching and commercial fishing of cod, lobster, hake, and other species (Eldredge 1993). 

Massachusetts Bay, and Stellwagen Bank in particular, show a marked concentration of biodiversity in comparison to the broader coastal North Atlantic. This diversity is supported from the bottom of the food chain. The pattern of currents and bathymetry in the area support high levels of phytoplankton productivity, which in turn support dense populations of schooling fish such as sand lance, herring, and mackerel, all important prey for larger fish, mammals, and seabirds (NOAA 2010). Sightings of many species of whales and seabirds are best predicted by spatial and temporal distribution of prey species (Jiang et al 2007; NOAA 2010), providing support for the theory that the region’s diversity is productivity-driven.

Stellwagen Bank is utilized as a significant migration stopover point for many species of shorebird. Summer visitors include Wilson’s storm-petrel, shearwaters, Arctic terns, and red phalaropes, while winter visitors include black-legged kittiwakes, great cormorants, Atlantic puffins, and razorbills. Various cormorants and gulls, the common murre, and the common eider all form significant breeding colonies in the sanctuary as well (NOAA 2010). The community of locally-breeding birds in particular is adversely affected by human activity. As land use along the shore changes and fishing activity increases, the prevalence of garbage and detritus favors gulls, especially herring and black-backed gulls. As gull survivorship increases, gulls begin to dominate competition for nesting sites, to the detriment of other species (NOAA 2010). 

In addition to various other cetaceans and pinnipeds, the world’s only remaining population of North Atlantic right whales summers in the Stellwagen Bank sanctuary. Right whales and other baleen whales feed on the abundant copepods and phytoplankton of the region, while toothed whales, pinnipeds, and belugas feed on fish and cephalopods (NOAA 2010). The greatest direct threats to cetaceans in the sanctuary are entanglement with fishing gear and death by vessel strikes (NOAA 2010), but a growing body of evidence suggests that noise pollution harms marine mammals by masking their acoustic communication and damaging their hearing (Clark et al 2009).

General threats to the ecosystem as a whole include overfishing and environmental contaminants. Fishing pressure in the Gulf of Maine area has three negative effects. First and most obviously, it reduces the abundance of fish species, harming both the fish and all organisms dependent on the fish as food sources. Secondly, human preference for large fish disproportionately damages the resilience of fish populations, as large females produce more abundant, higher quality eggs than small females. Third, by preferentially catching large fish, humans have exerted an intense selective pressure on food fish species for smaller body size. This extreme selective pressure has caused a selective sweep, diminishing the variation in gene pools of many commercial fisheries (NOAA 2010). While the waters of the SBNMS are significantly cleaner than Massachusetts Bay as a whole, elevated levels of PCBs have been measured in cetaceans and seabird eggs (NOAA 2010). Additionally, iron and copper leaching from the contaminated sediments of Boston Harbor occasionally reach the preserve (Li et al 2010). 


  • Clark CW, Ellison WT, Southall BL, Hatch L, Van Parijs SM, Frankel A, Ponirakis D. 2009. Acoustic masking in marine ecosystems: intuitions, analysis and implication. Inter-Research Marine Ecology Progress Series 395:201-222.
  • Eldredge, Maureen. 1993. Stellwagen Bank: New England’s first sanctuary. Oceanus 36:72.
  • Jiang M, Brown MW, Turner JT, Kenney RD, Mayo CA, Zhang Z, Zhou M. Springtime transport and retention of Calanus finmarchicus in Massachusetts and Cape Cod Bays, USA, and implications for right whale foraging. Marine Ecology 349:183-197.
  • Li L, Pala F, Mingshun J, Krahforst C, Wallace G. 2010. Three-dimensional modeling of Cu and Pb distributions in Boston Harbor, Massachusetts and Cape Cod Bays. Estuarine Coastal & Shelf Science. 88:450-463.
  • National Oceanographic & Atmospheric Administration. 2010. Stellwagen Bank National Marine Sanctary Final Management Plan and Environmental Assessment. “Section IV: Resource States” pp. 51-143. http://stellwagen.noaa.gov/management/fmp/pdfs/sbnms_fmp2010_lo.pdf
Creative Commons Attribution 3.0 (CC BY 3.0)

© Peter Everill

Supplier: Peter Everill

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Migration

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Trophic Strategy

Food Habits

The prey of L. acutus is usually a combination of shrimp, smelt, hake, squid and herring. These animals may separate from their school in order to feed more efficiently.

Animal Foods: fish; mollusks; aquatic crustaceans

Primary Diet: carnivore (Piscivore )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comments: Diet consists primarily of small pelagic fishes and squid (e.g., sand lance, silver hake, herring, common squid).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Fish, cephalopods and some shrimp.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

General Ecology

Gregarious. Inshore, group size generally is around 6-8; offshore, may form groups of up to several hundred; groups may segregate partially by age and/or sex (IUCN 1991).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History and Behavior

Behavior

Diet

various fish, squid, and some crustaceans
  • North-West Atlantic Ocean species (NWARMS)
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Cyclicity

Comments: Active day and night.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life Expectancy

Lifespan/Longevity

Average lifespan

Sex: female

Status: wild:
27.0 years.

Average lifespan

Sex: male

Status: wild:
22.0 years.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Lifespan, longevity, and ageing

Maximum longevity: 27 years (wild) Observations: Female maximum longevity in the wild has been estimated at 27 years.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Reproduction

Information on the mating system of these animals is not available.

The gestation period is about 10 months long. The calves are usually born in June and July. There is usually one young per a birth, averaging about 25 kg and 107 to 122 cm in size when born. The young are usually weaned at 18 months. The calving interval is 2 to 3 years.

Males become sexually mature between 2.1 and 2.4 m in length. Females become sexually mature between 1.94 and 2.22 m in length, which probably corresponds to 12 years of age (Klinowska, 1991). The maximum longevity of males is probably 22 years, whereas female longevity is 27 years.

Breeding interval: The calving interval is 2 to 3 years.

Average number of offspring: 1.

Average gestation period: 10 months.

Average weaning age: 18 months.

Average age at sexual or reproductive maturity (male): 12 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 24000 g.

Average gestation period: 316 days.

Average number of offspring: 1.25.

Average age at sexual or reproductive maturity (female)

Sex: female:
2231 days.

  • Klinowska, M. 1991. Dolphins, Porpoises and Whales of the World. Gland, Switzerland and Cambridge, U. K.: IUCN.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Mates in early fall. Gestation apparently lasts about 11 months. Single calf is born May-early August (mainly June/July) in western Atlantic. Young is weaned in about 18 months. Total length of the reproductive cycle may be at least 2.5 years. Females sexually mature in about 6-8 years, males in about 8-9 years.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Gestation period lasts for 10-12 months and calving takes place from May to August. Young are around 1.1 to 1.2 m long at birth. The calf nurses for about 18 months.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Lagenorhynchus acutus

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 3
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2008

Assessor/s
Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B.

Reviewer/s
Rojas-Bracho, L. & Smith, B.D. (Cetacean Red List Authority)

Contributor/s

Justification
The species is widespread and abundant (with current population estimates exceeding 100,000) and there have been no reported population declines or major threats identified.

History
  • 1994
    Insufficiently Known
    (Groombridge 1994)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Data on the population size of L. acutus is scarce but, the species is usually considered regionally abundant. The main threats today come from pollutants and entanglement in fishing gear (Whale and Dolphin Species Information, Humpback Whale and others, 1999).

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

National NatureServe Conservation Status

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: NU - Unrankable

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G4 - Apparently Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

There are no good estimates for the population of this species, but it appears to be abundant. There is still some commercial hunting, and some are taken incidentally in fishing gear. Listed in CITES Appendix II.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Gulf of Maine - CoML

Source: Gulf of Maine Area Census of Marine Life

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Status

Classified as Least Concern (LC) on the IUCN Red List (1). All cetaceans (whales and dolphins) are listed on Annex A of EU Council Regulation 338/97; they are therefore treated by the EU as if they are included in CITES Appendix I, so that commercial trade is prohibited. In the UK all cetaceans are fully protected under the Wildlife and Countryside Act, 1981 and the Wildlife (Northern Ireland) Order, 1985 (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Population

Population
This species is quite abundant throughout its range. There are an estimated 51,640 (CV=38%) Atlantic white-sided dolphins off the eastern North American shoreline (Waring et al. 2006) and about 96,000 (CV=54%) off the west coast of Scotland (MacLeod 2004). The number of Atlantic white-sided dolphins in the western North Atlantic, from the southern Gulf of Maine and north-eastward on the continental shelf and slope to Cabot Strait was about 27,000 in July - September 1995 (Palka et al. 1997) and was at least 11,740 (CV = 47%) in the Gulf of St. Lawrence (Kingsley and Reeves, 1998). There is currently little evidence for separate subpopulations (Mikkelsen and Lund 1994).

Population Trend
Unknown
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Threats

Major Threats
Some hunting for this species occurred in the past, especially in Norway. Some dolphins are still taken in Greenland, the Faroe Islands, and eastern Canada (Jefferson et al. 1993; Reeves et al. 1999). Recent catches in Faroe Islands were 333 and 310 in 2004 and 2005, respectively (NAMMCO 2005). No assessment is associated with the Faroese hunting of white-sided dolphins, but there is no evidence that this aspect of the drive fishery has a long history, such as that of the pilot whale component (Reeves et al. 2003).

Incidental mortality in fishing gear has been documented off Canada, the United States, the United Kingdom and Ireland. Gaskin (1992) judged Atlantic white-sided dolphins to be less vulnerable to capture in pelagic near-surface drift nets and fixed groundfish gill nets than are many other small cetaceans. They may, however, be especially susceptible to capture in midwater trawl nets (Addink et al. 1997). Substantial numbers have been bycaught in pelagic trawl fisheries for horse mackerel and mackerel south-west of Ireland (Reeves et al. 1999).

Morizur et al. (1999) investigated marine mammal bycatch in 11 pelagic trawl fisheries operated by four different countries in the Northeast Atlantic. One of the main marine mammal species identified in bycatches was L. acutus. Mean dolphin catch rate for all fisheries combined was 0.048+0.013 per tow (one dolphin per 20.7 tows), or 0.0185+0.0019 per hour of towing (one dolphin per 98 h of towing). All dolphin by-catches occurred during the night. White-sided dolphins were observed feeding around the net during towing; this behaviour may make them more vulnerable to capture. Operational difficulties in observing bycatch and potentially significant annual fluctuation in catch rates warrant further observer studies of these and other trawl fisheries. Substantial numbers have been by-caught in trawl fisheries south-west of Ireland (Couperus 1997a, b), and takes have also been recorded in gill-net and trawl fisheries along the US Atlantic coast (Waring et al. 2008).

Like other North Atlantic marine mammals, Atlantic white-sided dolphins are contaminated by organochlorines, other anthropogenic compounds and heavy metals (Reeves et al. 1999); although the effects of pollutants are not well understood in this species, they may affect reproduction or render them susceptible to other mortality factors.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comments: No direct threats at present; potential threats include groundfish gill nets off eastern U.S. and Canada, salmon drift nets in the Labrador Sea, and possible spills from future offshore oil development (Gaskin 1992).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Threats to the Atlantic white-sided dolphin include hunting, chemical pollution, environmental change and entanglement in fishing nets, which results in drowning (4).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
The species is listed in Appendix II of CITES.

Existing direct takes are currently not regulated by any hunting quotas. Operational difficulties in observing bycatch and potentially significant annual fluctuation in catch rates warrant further observer studies of these and other trawl fisheries (Morizur et al. 1999; Waring et al. 2006). The impact of combined anthropogenic removals should be assessed.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

A UK Biodiversity Action Plan priority species, the Atlantic white-sided dolphin is protected in UK waters by the Wildlife and Countryside Act 1981 and the Wildlife (Northern Ireland) Orders, 1985; it is illegal to intentionally kill, injure, or harass any cetacean (whale or dolphin) species in UK waters (3). The Agreement on the Conservation of Small Cetaceans in the Baltic and North Seas (ASCOBANS) has been signed by seven European countries, including the UK. Provision is made under this agreement to set up protected areas, promote research and monitoring, pollution control and increase public awareness (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

A small number are caught in fishing nets each year, causing damage to fishing productivity.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Economic Importance for Humans: Positive

Occasionally, L. acutus is captured deliberately by fisherman off Newfoundland, Norway, and the British Isles, presumably to be sold in fresh meat markets (Nowak, 1999). Historically, L. acutus has also been hunted by Greenland. The Faeroe Islands take hundreds of L. acutus every year, by driving large schools ashore (Cetacea: Lagenorhynchus acutus, 1999). Unlike many other dolphin species, L. acutus has not been reported to be in captivity (Atlantic white-sided dolphin, 1999).

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Economic Uses

Comments: Not important as a subsistence or commercial resource. Taken directly in small number in Greenland (IUCN 1991).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Risks

IUCN Red List Category

Least Concern (LC)
  • IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Atlantic white-sided dolphin

The Atlantic white-sided Dolphin (Lagenorhynchus acutus) is a distinctively coloured dolphin found in the cool to temperate waters of the North Atlantic Ocean.

Taxonomy[edit source | edit]

The Atlantic white-sided Dolphin was named by John Edward Gray in 1828. The specific name acutus comes from the Latin for 'pointed' and refers to the sharply pointed dorsal fin. L. acutus is one of six oceanic dolphins in the genus Lagenorhynchus.

Physical description[edit source | edit]

An Atlantic white-sided dolphin off the coast of Cape Ann, Massachusetts

The dolphin is slightly larger than most other oceanic dolphins. It is just over a meter in length at birth, growing to about 2.8 m (9.2 ft) (males) and 2.5 m (8.2 ft) (females) at maturity. It weighs 200–230 kg (440–510 lb) once fully-grown. Females reach sexual maturity at between 6 and 12 years, and males between 7 and 11 years. The gestation period is 11 months and lactation lasts for about a year and a half — both typical figures for dolphins. Individuals are known to live for up to 22 years (males) and 27 years (females).

The key distinguishing feature is the white to pale yellow patch found behind the dorsal fin of the dolphin on each side. This variation in colour to the Atlantic white-sided Dolphin is unique amongst the mixtures of white, greys and blues of other pelagic cetaceans. The rest of the body's coloration is well demarcated: the chin, throat and belly are white; the flippers, dorsal fin and back are dark grey to black with the exception of the yellow patch; there is a further white patch below the dorsal fin, lying above a light grey stripe that runs from the beak, above the eye and down to the tail stock.

Dolphin group sizes vary by location, with groups averaging 60 in number close to the Newfoundland shores, but rather smaller east of Iceland. From the analysis of the stomach contents of stranded animals, fish such as herring and mackerel and squid appear to form the species' main diet. The Atlantic white-sided Dolphin is fairly acrobatic and keen to interact with boats, however it is not as wildly gregarious as the White-beaked and Common Dolphins.

Population and distribution[edit source | edit]

The species is endemic to the North Atlantic Ocean. Areas of particularly high population density include the shores of Newfoundland and Cape Cod, the triangular area of sea between the United Kingdom, Iceland and Greenland and the North Sea. The total population is believed to be 200-300,000 individuals.

Human interaction[edit source | edit]

Hvalba, Faroe Islands in August 2006

Historically, Atlantic white-sided Dolphins were killed in drives conducted from Norway and Newfoundland. These have ceased in recent years, although they still occur to a lesser extent from the Faroe Islands, where the meat and blubber are in high regard as food.[2]

Reported catches in the years from 1995 to 1998 were 157, 152, 350, and 438, respectively (Bloch and Olsen 1998, 1999; Bloch et al. 1997, 2000). In 2002, the number reported killed was 774. [2]

Conservation[edit source | edit]

The North and Baltic Sea populations of the Atlantic white-sided dolphin are listed on Appendix II [3] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). They are listed on Appendix II[3] as they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.[4]

In addition, the Atlantic white-sided dolphin is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS).[5]

See also[edit source | edit]

References[edit source | edit]

  1. ^ Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. (2008). Lagenorhynchus acutus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 24 March 2009. Database entry includes a brief justification of why this species is of least concern.
  2. ^ a b UMSITINGEN: 10JUNR2003 report by the Faroe Islands' Prime Minister's Office, entitled: Whales & Whaling in the Faroe Islands
  3. ^ a b "Appendix II" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5th March 2009.
  4. ^ Convention on Migratory Species page on the Atlantic white-sided dolphin
  5. ^ Official website of the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Names and Taxonomy

Taxonomy

Comments: LeDuc et al. (1999) used cytochrome b gene sequences to examine phylogenetic relationships among delphinids and found that Lagenorhynchus albirostris (type species for the genus) and L. acutus are not closely related to each other or to nominal congeners; acutus was therefore assigned to the genus Leucopleurus. The remaining four Lagenorhynchus species are closely related to Lissodelphis and Cephalorhynchus and were placed in the genus Sagmatias. However, this revision has not been widely accepted and, pending further evidence, the mammal checklists by Baker et al. (2003) and Mead and Brownell (in Wilson and Reeder 2005) maintained acutus and obliquidens in the genus Lagenorhynchus.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!