“Standard methods in video” was prepare to improve standarization of data collection for different groups that are working in CEMP.
It was made under recommendation of WG CEMP) (Stockholm 1990) endorsed by the Scientific Committee ( Report Ninth Meeting of the Scientific Committee pag 38 5.17). The video was made in PAL N system.
Abstract:
“The penguins and the man” is a video made with the three main goals, the first two are general, for the scientific communities and the third is an specific one, to introduce argentine people involved in work for CEMP.
1.- The first objective is to show basic biology of adelie penguins necesary to understand principles of CEMP standard methods.
2.- The second is to introduce philosophical principles of the Convention and CEMP.
3.- The third is to show to argentine workers, specially for their first time in Antarctica, how is the way and the work that they will do.
It was made under recommendation of WG CEMP (Stockholm 1990) endorsed by the Scientific Committee ( Report Ninth Meeting of the Scientific Committee pag 38 5.17). The video was made in PAL N system.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
Abstract:
A census of the breeding population of Antarctic fur seals (Arctocephalus gazella) at South Georgia was carried out during the 1990/91 breeding season. Using counts of adult females ashore at the breeding grounds during the pupping period, together with corrections for the likelihood of a female being ashore at a census and for pregnancy rate (71 % in 1990/91), pup production was estimated as 269,000 (95% confidence intervals 188,000 - 350,000). The breeding population in 1990/91 was reduced at long-term study sites probably because of a short term reduction in food availability. Data from these sites were used to estimate the pup production of the population had 1990/91 been a typical year. Based on values from 1983/84 to 1990/91, pup production in 1990/91 would have been 378,000 (S.E. = 19,100) if it had been an average year. The annual increase from 1976/17 to 1990/91 was 9.8% which shows that the rate of increase in pup production has declined since the initial period of population expansion in the 1950s and 1960s. Increased population size has led to an expansion of the breeding range at South Georgia.
There is no abstract available for this document.
Abstract:
We studied diving patterns and performance (dive depth, duration, frequency and organization during the foraging trip) in relation to diet in nonbreeding Gentoo Penguins (Pygoscelis papua) over 59 days (involving 5,469 dives) in winter. We estimated foraging ranges and prey capture rates, and compared foraging behavior with that of breeding (chick-rearing) birds. Foraging was highly diurnal with 98% of foraging trips completed during the same day. Foraging-trip frequency was 0.8/day, trip duration was 6-8 h, and birds spent 51-62% of the foraging trip diving. Dive depth and duration were bimodal. Shallow dives (30 m; 55% of total number and 81% of dive time) averaged 74-105 m and 2.7-3.5 min, respectively. Deep-dive duration exceeded the subsequent surface interval, but shallow dives were followed by surface intervals two to three times dive duration. Deep dives showed clear diel patterns, averaging 10-20 m at dawn and dusk and 70-90 m at midday. These results are consistent with the patchy vertical and horizontal distribution and diel movements of Antarctic krill, the main winter prey of Gentoo Penguins (including study birds). We suggest that shallow dives are mainly searching dives, and deep dives mainly for feeding. Foraging activity of non breeding Gentoo Penguins in winter is similar to that of chick-rearing birds. The only major differences are that foraging-trip frequency is 20% less and stomach-content mass on return ashore 30% less in winter. We conclude that foraging activity in Gentoo Penguins is changed by varying the frequency and duration of foraging trips, rather than by changing the pattern and rate of diving.
Abstract:
The foraging ranges of six female and four male Adélie penguins breeding at Bechervaise Island near Mawson Station (Mac. Robertson Land) were determined by satellite tracking, using the ARGOS system. Birds were tracked over four foraging trips (by 2 females and 4 males) during the incubation period (November-December 1991) and 17 trips (by 4 females and 2 males) throughout January 1992 when birds were feeding chicks. Most birds made foraging trips to the continental shelf break (1000m isobath) approximately 110 km distant at its closest point. Birds feeding chicks also made journeys of 1-2 days ranging up to 12 km after 17 January when the sea became ice free to the coast. Concentrations of krill Euphausia superba which have in the past been the subject of a fishery occur along the shelf break zone where the birds were foraging. There is potential therefore for overlap between the foraging range of Adélie penguins breeding along the Mac. Robertson Land Coast (approximately 150000 pairs) and any future harvest of krill in the region. The foraging range of the birds at Bechervaise Island considerably exceeds the 15-50 km determined for birds in the South Shetland and South Orkney Islands and reflects the distance offshore of krill one of their major food sources.
Abstract:
Temporal and spatial variability of krill distribution features was investigated at the micropolygon of 8 x 6 miles, where eight consecutive hydroacoustic stations were carried out. Krill aggregations occurred as fields of small swarms of spatial distribution features (size and density of swarms, swarm field density, number of swarms per one mile) varied considerably from tack to tack within each survey. Horizontal extension of swarms amounted to 120 m, however about 70% of swarms were of 30 m in length, with density up to 200 g/m3. About 75% of all swarms revealed bad biomass of less 1 t. Average statistical parameters of swarms at polygon varied insignificantly from survey to survey, while the swarm number varied within the broad range from 1918 to 7000 and further to 1554 units. Krill biomass at polygon varied spasmodically within the range from 1091 to 6085 t. Krill distribution variability revealed at polygon suggests the impulsive nature of krill enter and exit out of the polygon due to its transport by the current. Besides, in the upper layer of 0-50 m the swarm number was a almost constant, and krill redistribution due to transport and diurnal migrations occurred in the layer of 5-150 m. Estimated velocity of krill swarms displacement corresponds to the estimated water transport velocity at the polygon, suggesting the passive krill transport occurred. Krill biomass transported across different tacks also varied spasmodically from survey to survey.