Consumption of euphausiids by harbour porpoise (Phocoena phocoena) calves in the Bay of Fundy

1992 ◽  
Vol 70 (8) ◽  
pp. 1629-1632 ◽  
Author(s):  
Richard J. Smith ◽  
Andrew J. Read
Keyword(s):  
Fish Species ◽  
Prey Item ◽  
Stomach Contents ◽  
Harbour Porpoise ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Gill Nets ◽  
Meganyctiphanes Norvegica

We compared the contents of 31 stomachs of harbour porpoise calves killed in commercial gill nets in the Bay of Fundy between July and September, 1985–1991, with the stomach contents from 149 adult animals obtained from the same source between July and September, 1988–1991. The calves' most common prey item was the euphausiid Meganyctiphanes norvegica, found in 15 stomachs, whereas the adults fed primarily on clupeid and gadid fishes. Euphausiids were also found in the stomachs of several of these fish species, and we suggest that porpoise calves take euphausiids while their mothers are feeding on other euphausiid predators.

Mitigation of harbour porpoise (Phocoena phocoena) by-catch in the gillnet fishery in the lower Bay of Fundy

1999 ◽  
Vol 56 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Edward A Trippel ◽  
Michael B Strong ◽  
John M Terhune ◽  
Jeremy D Conway
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Field Testing ◽  
Harbour Porpoise ◽  
Clupea Harengus ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
By Catch ◽  
Catch Rates ◽  
Wind Sea

Demersal gill nets equipped with acoustic alarms reduced harbour porpoise (Phocoena phocoena) by-catch rates by 77% over those without alarms in the Swallowtail area of the lower Bay of Fundy during field testing in August 1996 (68% reduction) and 1997 (85% reduction) (both years combined, three harbour porpoises in 249 alarmed nets versus 14 harbour porpoises in 267 nonalarmed nets). The alarms spaced 100 m apart along the net floatline produced a 0.3-s pulse at 10-12 kHz every 4 s at a level of 133-145 dB re 1 µPa at 1 m. In conditions of no rain and low wind (Sea State 0-2) the alarms were presumed to be clearly audible to harbour porpoises at ranges of 0.1-0.6 km. Catch rates of Atlantic herring (Clupea harengus), Atlantic cod (Gadus morhua), and pollock (Pollachius virens) were not significantly different in alarmed and nonalarmed nets (except in one season when pollock were caught in lower numbers in alarmed nets). Harbour porpoise by-catch and herring movements may be linked. During years of low herring abundance, we also observed low harbour porpoise entanglement rates.

Diving behaviour of harbour porpoises, Phocoena phocoena

1995 ◽  
Vol 52 (5) ◽  
pp. 1064-1073 ◽  
Author(s):  
Andrew J. Westgate ◽  
Andrew J. Head ◽  
Per Berggren ◽  
Heather N. Koopman ◽  
David E. Gaskin
Keyword(s):  
Data Collection ◽  
Dive Depth ◽  
Maximum Depth ◽  
Diving Behaviour ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Diel Pattern ◽  
Maximum Capacity ◽  
Gill Nets ◽  
Free Ranging

The diving behaviour of seven free-ranging harbour porpoises (Phocoena phocoena) was examined using time–depth recorders. In total, 8167 individual dives were recorded over 254 h. The longest period of data collection from an individual was 106.1 h. Mean dive depths and durations ranged from 14 ± 16 to 41 ± 32 m, and from 44 ± 37 to 103 ± 67 s, respectively. The maximum recorded dive depth and duration was 226 m and 321 s. This performance may not represent the maximum capacity of harbour porpoises but rather the maximum depth of the study area. Individual dives had similar rates of descent and ascent, which ranged from 1.1 ± 0.6 to 2.3 ± 1.4 m/s, and from 0.9 ± 0.6 to 2.1 ± 1.4 m/s, respectively. Two porpoises with monitoring periods >2 days demonstrated a diel pattern in their diving, making fewer, but deeper dives at night. Comparison of the diving behaviour of harbour porpoises with data on the depth of 140 porpoises entanglements in groundfish gill nets in the Bay of Fundy showed these seven porpoises made between 22 and 70% of dives to depths (range 20–130 m) where the majority of entanglements were reported.

Individual and geographical variation in pigmentation patterns of the harbour porpoise, Phocoena phocoena (L.)

1994 ◽  
Vol 72 (1) ◽  
pp. 135-143 ◽  
Author(s):  
H. N. Koopman ◽  
D. E. Gaskin
Keyword(s):  
British Columbia ◽  
New Record ◽  
Geographical Variation ◽  
Individual Recognition ◽  
Harbour Porpoise ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Geographically Isolated

Photographs of 393 harbour porpoises (Phocoena phocoena (L.)) from the waters of Denmark (n = 224), Japan (n = 19), and Canada (Bay of Fundy (n = 95), Gulf of St. Lawrence (n = 40), and coast of British Columbia (n = 15)) were analyzed for variation in pigmentation patterns. Animals were classified according to morphs of each of 12 pigmentation characters. Patterns were not unique to particular areas and cannot be used as a tool for absolute discrimination among geographically isolated groups of porpoises. However, statistical frequencies of certain morphs of seven characters varied significantly among the five geographical groups, matching some of the subpopulations proposed by Gaskin in 1984. Pigmentation patterns of harbour porpoises were unique to each animal and were not gender dependent. Variation in pigmentation patterns may have implications for intra-individual recognition. All porpoises showed bilaterally asymmetrical pigmentation, providing a new record of consistent asymmetry in an odontocete species.

Incidental mortality of harbour porpoise (Phocoena phocoena) by the gill-net fishery in the lower Bay of Fundy

1996 ◽  
Vol 53 (6) ◽  
pp. 1294-1300 ◽  
Author(s):  
E A Trippel ◽  
J Y Wang ◽  
M B Strong ◽  
L S Carter ◽  
J D Conway
Keyword(s):  
Harbour Porpoise ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Gill Net ◽  
Incidental Mortality

Postnatal growth and allometry of harbour porpoises from the Bay of Fundy

1997 ◽  
Vol 75 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Andrew J. Read ◽  
Krystal A. Tolley
Keyword(s):  
Growth Rates ◽  
Growth Curves ◽  
Postnatal Growth ◽  
The Body ◽  
Harbour Porpoise ◽  
Body Region ◽  
Bay Of Fundy ◽  
Commercial Fisheries ◽  
Phocoena Phocoena ◽  
Thoracic Region

We described patterns of growth and allometry from observations of 203 female and 198 male harbour porpoises, Phocoena phocoena, killed in commercial fisheries in the Bay of Fundy between 1985 and 1993. Gompertz growth curves were used to predict length, mass, and girth at physical maturity. Asymptotic sizes and growth rates were greater in females for all three characters. The pattern of allometry was consistent between sexes, but varied according to body region. The characters in the head and thoracic regions exhibited negative allometry, but those in the posterior of the body were isometric. Most characters showed the same growth rates for the two sexes, except those in the thoracic region, for which females exhibited faster growth than males. These results are consistent with those of several other studies of the harbour porpoise in which faster growth and larger sizes are attained by females.

Harbour Porpoise (Phocoena phocoena) Presence Patterns at an Aquaculture Cage Site in the Bay of Fundy, Canada

2009 ◽  
Vol 35 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Marthe L. Haarr ◽  
Laura D. Charlton ◽  
John M. Terhune ◽  
Edward A. Trippel
Keyword(s):  
Harbour Porpoise ◽  
Bay Of Fundy ◽  
Phocoena Phocoena

Summer Diet of the Harbour Porpoise (Phocoena phocoena) in the Estuary and the Northern Gulf of St. Lawrence

1994 ◽  
Vol 51 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Pierre-Michel Fontaine ◽  
Mike O. Hammill ◽  
Cyrille Barrette ◽  
Michael C. Kingsley
Keyword(s):  
Stomach Contents ◽  
Harbour Porpoise ◽  
Clupea Harengus ◽  
Frequency Of Occurrence ◽  
Atlantic Herring ◽  
Phocoena Phocoena ◽  
Mallotus Villosus ◽  
Important Species ◽  
Caloric Value ◽  
Capelin Mallotus Villosus

Stomach contents (n = 138) were examined in harbour porpoise (Phocoena phocoena) caught incidently by commercial fishermen in the estuary and the Gulf of St. Lawrence; 111 stomachs contained food. A total of 4423 otoliths and 11 upper beaks were collected belonging to nine species of fishes and one species of squid. Capelin (Mallotus villosus), Atlantic herring (Clupea harengus), and redfish (Sebastes marinus) were the three most important species in the diet by frequency of occurrence (83, 8, and 4.5%, respectively) and percent occurrence in the stomachs (52, 49, and 8.5%). Capelin and herring also made the greatest mass and caloric contribution to the diet of porpoise (>80%). The estimated mean mass and caloric value of the stomach contents of a nonlactating adults were 958 g and 7007 kJ, respectively.

scholarly journals Growth of the harbour porpoise (Phocoena phocoena) in eastern Newfoundland, Canada

2003 ◽  
Vol 5 ◽  
pp. 211
Author(s):  
S F Richardson ◽  
G B Stenson ◽  
C Hood
Keyword(s):  
Growth Rates ◽  
Gulf Of Maine ◽  
Harbour Porpoise ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Growth Data ◽  
West Greenland ◽  
Gompertz Growth Model ◽  
One Year ◽  
Separate Population

Although the stock relationships among harbour porpoise (Phocoena phocoena) in the Northwest Atlantic are unknown, it has been postulated that there are 4 local populations: Bay of Fundy/Gulf of Maine, Gulf of St. Lawrence, Newfoundland, and west Greenland. Data on the Newfoundland population are extremely limited. To determine growth rates and examine if these animals can be differentiated from other sub-populations on the basis of growth characteristics, 94 porpoises caught incidentally in fishing gear along the southeast coast of Newfoundland during the summers of 1990 and 1991 were examined. Most porpoises (56%) were ≤ 4 years of age. Maximum age was 9 for females and 12 for males. Growth rates were similar for both sexes until one year of age, after which females grew longer and weighed more than males of similar ages. Using the Gompertz growth model, asymptotic values for body length were 156.3 cm for females and 142.9 cm for males. Asymptotic weights were 61.6 kg and 49.1 kg for females and males respectively. With the exception of West Greenland porpoise that were shorter and females from Norway that were lighter, Newfoundland porpoises could not be differentiated from animals collected in other areas based on growth data. However, differences in dental deposition patterns were noted suggesting that Newfoundland porpoise may belong to a separate population.

Stomach contents of harbour porpoises, Phocoena phocoena (L.), from the Bay of Fundy

1989 ◽  
Vol 67 (9) ◽  
pp. 2140-2146 ◽  
Author(s):  
Cheri A. Recchia ◽  
Andrew J. Read
Keyword(s):  
Gadus Morhua ◽  
Prey Species ◽  
Atlantic Cod ◽  
Caloric Intake ◽  
Stomach Contents ◽  
Clupea Harengus ◽  
Spatial And Temporal Variation ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Total Caloric Intake

We examined contents from stomachs of 127 harbour porpoises (Phocoena phocoena) caught in groundfish gill nets in the western Bay of Fundy during June to September, 1985–1987. Relative importance of prey species was assessed using both numerical and caloric measures. Atlantic herring (Clupea harengus) was the most important prey species, contributing 80% of the total caloric intake, with some spatial and temporal variation. Silver hake (Merluccius bilinearis) and Atlantic cod (Gadus morhua) were also important, but together comprised only 17% of the total caloric intake. No differences were found in relative prey importance between adult porpoises of different reproductive conditions, but lactating females ingested more fish and had a significantly higher total caloric intake than nonlactating females or mature males. The diet of porpoises collected from the same area in 1969–1972 consisted of a higher proportion of pelagic prey species and a lower proportion of demersal species. This may be attributed to differences in capture method, as the earlier sample of porpoises was collected at the surface, while the present animals were captured at depths of 45–100 m.

Observations on the ventilation cycle of the harbour porpoise Phocoena phocoena (L.) in coastal waters of the Bay of Fundy

1983 ◽  
Vol 61 (1) ◽  
pp. 126-132 ◽  
Author(s):  
A. P. Watson ◽  
D. E. Gaskin
Keyword(s):  
Coastal Waters ◽  
Marine Mammals ◽  
Average Duration ◽  
Extended Period ◽  
Harbour Porpoise ◽  
Orcinus Orca ◽  
Behaviour Pattern ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Observation Period

The ventilation cycle of the harbour porpoise was studied through analysis of 700 dive sequences recorded in the Fish Harbour region of southern New Brunswick. Two basic ventilation patterns were recognized; one (pattern A) was exhibited by travelling animals and was characterized by short submergence periods (24.4 ± 1.6 s (SE)), the second (pattern B) by animals apparently feeding, and was characterized by restricted ventilation periods, between which the submergence periods averaged 1.44 ± 0.07 min. Submergences during pattern B behaviour ranged from 35 s to 4 min 4 s. One animal observed over an extended period took considerably more breaths (6.6 ± 0.4) after dives of above-average duration than after dives of less than average duration (3.6 ± 0.2). We found that the number of breaths per minute in each behaviour pattern were very similar (2.4 and 2.3, respectively), supporting statements by other workers that the energetic demands of diving in marine mammals may not be greater than that required for surface activity. In behaviour patterns A and B, respectively, harbour porpoises in this area were at the surface for only 7.2 and 7.5% of any observation period. The maximum to mean dive-time ratio in P. phocoena was noted as being almost identical to that observed in Orcinus orca; this may be a generalized relationship in all odontocetes.

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