摘要:

SummarySeabirds were counted along standard transect routes off Phillip Island and within Port Phillip Bay, Victoria. During these surveys 37 taxa were recognised, although only 10–11 were regularly seen. Of 25 taxa recorded within Port Phillip Bay, 16 were also included in the 28 seen off Phillip Island. Differences between sites related mainly to the occurrence of albatross species off the coast, and the variety of terns seen within Port Phillip. Off Phillip Island, most records were of Short-tailed ShearwaterPuffinus tenuirostriswhich dominated the estimated biomass; in Port Phillip Bay the Silver GullLarus novaehollandiaewas numerically more important though the Australasian GannetMorus serratorcontributed more to the biomass. In general, areas off Phillip Island supported a higher average density and biomass than did those in Port Phillip Bay, primarily due to the seasonal influx of shearwaters during breeding periods. Commoner species, apart from cormorants and shags, were seen to the southern-most ends of transects run off Phillip Island. Main feeding methods are considered and it appears that the species occurring off Phillip Island are essentially polyvorous, taking a range of prey species, whilst most in Port Phillip are piscivorous.

ISSN:0158-4197    

DOI:10.1071/MU9910377

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryA brief summary is given of the chemical and biological oceanography of Bass Strait, as far as it is relevant to the food supply of Little PenguinsEudyptula minorand the environment in which they live. Four water masses are considered to affect Bass Strait. These are North Bass Strait Water, Central Tasman Water, Subantarctic Water and East Australian Current Water. They vary greatly in nutrient status and the effects of this on productivity (about which little is known) and resulting plankton biomass is discussed. It appears that phytoplankton biomass is greatest near the extremities of Bass Strait but zooplankton biomass may be greater within Bass Strait.

ISSN:0158-4197    

DOI:10.1071/MU9910395

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryColonies of Little PenguinsEudyptula minoron Phillip Island, Victoria, have declined in both breeding areas and numbers. This decrease, and recent mortalities, stimulated research to support a‘Penguin Protection Plan’that started in 1985. Aspects of this research and its management implications are reviewed. Historically, land alienation and subdivision reduced colony distribution. Mortalities at sea have been obvious for some time: those of adults usually involved few birds in Port Phillip Bay. Immature birds die off western Victoria (probably regularly, and occasionally in large numbers): these mortalities may be associated with starvation and endoparasites. Breeding periods have shortened in the past 20 years, and hence reduced potential recruitment, and there are increased losses in the pre-breeding age group. Some losses are due to continuing predator activities (mainly fox) but studies suggest that climate changes, reflected in sea temperature, may play a role in population regulation presumably through food availability. Off Phillip Island, Little Penguins take a range of prey, principally small schooling clupeoids, and breeding can be delayed if these are unavailable. Fish sampling showed the changing abundance and patchy distribution of food and the birds' distribution sometimes related to that of prey. Adults use Port Phillip Bay in non-breeding periods and overfishing of main prey species could affect Little Penguins: commercial catches of Pilchards have increased substantially, but they involve larger fish. There is no commercial Pilchard fishery off the Phillip Island colonies. Present land-management practices favour the Little Penguin on Phillip Island but prospects of moderating at-sea factors are small. A better understanding of the Little Penguins' marine ecosystem is required.

ISSN:0158-4197    

DOI:10.1071/MU9910402

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor