The food of the Common porpoise (<i>Phocaena phocaena</i>)

Rae, B. B.

doi:10.1111/j.1469-7998.1965.tb05204.x

Cited by 21 publications

(2 citation statements)

References 7 publications

(4 reference statements)

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“…However, differences in seasonal distributions of the two species suggest different prey and prey size preferences (cf. Rae 1965 , 1973 ). Increases in porpoise occurrence in winter may coincide with concentrations of herring, typically an important prey species in areas where it occurs commonly (Recchia and Read 1989 ; Gannon et al 1998 ; Börjesson et al 2003 ; Sveegaard et al 2012 ), although there is no evidence for this in Cardigan Bay.…”

Section: Discussionmentioning

confidence: 99%

Don’t forget the porpoise: acoustic monitoring reveals fine scale temporal variation between bottlenose dolphin and harbour porpoise in Cardigan Bay SAC

et al. 2017

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Populations of bottlenose dolphin and harbour porpoise inhabit Cardigan Bay, which was designated a Special Area of Conservation (SAC), with bottlenose dolphin listed as a primary feature for its conservation status. Understanding the abundance, distribution and habitat use of species is fundamental for conservation and the implementation of management. Bottlenose dolphin and harbour porpoise usage of feeding sites within Cardigan Bay SAC was examined using passive acoustic monitoring. Acoustic detections recorded with calibrated T-PODs (acoustic data loggers) indicated harbour porpoise to be present year round and in greater relative abundance than bottlenose dolphin. Fine-scale temporal partitioning between the species occurred at three levels: (1) seasonal differences, consistent between years, with porpoise detections peaking in winter months and dolphin detections in summer months; (2) diel variation, consistent across sites, seasons and years, with porpoise detections highest at night and dolphin detections highest shortly after sunrise; and (3) tidal variation was observed with peak dolphin detections occurring during ebb at the middle of the tidal cycle and before low tide, whereas harbour porpoise detections were highest at slack water, during and after high water with a secondary peak recorded during and after low water. General Additive Models (GAMs) were applied to better understand the effects of each covariate. The reported abundance and distribution of the two species, along with the temporal variation observed, have implications for the design and management of protected areas. Currently, in the UK, no SACs have been formally designated for harbour porpoise while three exist for bottlenose dolphins. Here, we demonstrate a need for increased protection and species-specific mitigation measures for harbour porpoise.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-017-3081-5) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

Don’t forget the porpoise: acoustic monitoring reveals fine scale temporal variation between bottlenose dolphin and harbour porpoise in Cardigan Bay SAC

et al. 2017

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“…This highlights a potential source of bias in the samples (i.e., that the overall picture of diet composition depends on the source of samples) but also has conservation implications. In the UK, studies on the diet of grey (Halichoerus grypus) and harbour (Phoca vitulina) seals during the 1950s and 1960s (Rae, 1960(Rae, , 1965(Rae, , 1968(Rae, , 1973 were widely criticised for relying on data from seals shot by Table 1 for list of abbreviations. fishermen (in this case, legally) because the seals had entered coastal salmon nets on the east coast of Scotland.…”

Section: Discussionmentioning

confidence: 99%

Diet of the Monk Seal (Monachus monachus) in Greek Waters

Pierce¹,

Hernández-Milian

Santos

et al. 2011

Aquat Mamm

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Stomach contents were collected from 27 monk seal carcasses between 1997 and 2008 from different areas along the Greek coast. This sample included nine animals that had been deliberately killed and five accidental deaths due to fisheries interactions. Stomachs from monk seals of both sexes, including adults and subadults, were analysed. A total of 530 prey items from at least 71 prey species was identified, with approximately 74% of prey identified at least to genus, while 2.8% could be identified only to class level (i.e., fish or cephalopods). We found 266 cephalopods (50%), 253 fish (48%), a few non-cephalopod molluscs (1.5%), and two crustaceans (0.4%). Faecal samples were also collected but contained no identifiable prey remains. Octopuses were the most important prey in terms of numbers eaten and contribution to reconstructed prey biomass. The common octopus (Octopus vulgaris) (33.9% of prey by number) was around three times as numerous in the diet as the lesser octopus (Eledone cirrhosa) (11.1%). Fish of the families Sparidae (28.1%) and, to a lesser extent, Scorpaenidae (2.3%), Congridae (2.5%), and Atherinidae (2.5%) were also frequent in the stomachs. Many of the prey species recorded are of commercial fishery importance. Exploratory multivariate analysis (redundancy analysis [RDA]) indicated weakly significant seasonal, spatial, and interannual variation in diet and also suggested a relationship between diet composition and cause of death. No trends in diet related to sex or age class were identified. Sparids occurred more frequently in animals that had been deliberately killed than those that had died due to other causes, highlighting the interactions taking place between monk seals and fishing activities.

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