20 research outputs found
A short review of the distribution of short-beaked common dolphins (Delphinus delphis) in the central and eastern North Atlantic with an abundance estimate for part of this area
This paper uses data from 3 programmes: (1) the North Atlantic Sightings Surveys (NASS) surveys undertaken throughout much of the central and eastern North Atlantic north of about 40° N in 1987, 1989, 1995 and 2001; (2) the MICA-93 programme; and (3) the north eastern Atlantic segment of the Small Cetacean Abundance in the North Sea (SCANS) survey in 1994. The data from all surveys were used to examine the distribution of common dolphins in the NE Atlantic. No sightings were made north of 57° N. An initial attempt to examine distribution against 4 potential non biological explanatory variables was made. A simple interpretation of the preliminary analyses presented here is that the primary areas for groups of common dolphins were in waters over 15° C and depths of 400-1,000 m (there does appear a link with shelf features), between around 49°-55° N especially between 20°-30°W. An illustrative example of spatial modelling is presented. Only for 1 year (and part of the total survey area) were there sufficient data to attempt to estimate abundance: 1995. The estimated abundance in the W Block of the NASS-95 Faroese survey was 273,159 (cv=0.26; 95% CI=153,392-435,104) short-beaked common dolphins. This estimate is corrected for animals missed on the trackline (g(0)) and for responsive movement.Publisher PDFPeer reviewe
Decrease Stress; Train Your Animals: The Effect of Handling Methods on Cortisol Levels in Harbour Porpoises (Phocoena phocoena) Under Human Care
Circulating cortisol levels are accepted as a sensitive indicator of acute stress in marine mammals, particularly in relation with capture and handling. The present study provides the first long-term monitoring of cortisol levels in four harbour porpoises held in human care—an adult male and adult female and two juvenile females. It also compares levels in blood obtained after removing the animal from the water (OWR sampling) with levels in blood obtained at poolside under voluntary husbandry behaviours (VHB sampling). Cortisol levels differed significantly between the four porpoises, although they all exhibited quite high variations in cortisol levels, with averages of 64.9 and 70.5 μg/l in the adult male and female, respectively, and 90.7 and 51.4 μg/l in the juvenile females. OWR sampling induced significantly higher cortisol levels than VHB sampling, with a dramatic threefold decrease in circulating cortisol levels obtained under VHB sampling compared to levels obtained under OWR sampling (16.6 and 20.2 μg/l compared with 64.9 and 70.5 μg/l in the adult male and female respectively). Even if the porpoises showed some habituation to handling, regular and frequent handling over several years did not suppress a significant stress response in the porpoises when they were removed from the water, pointing to the advantage of using VHB for limiting stress in husbandry practices
Determination of growth, mass, and body mass index of harbour porpoises (Phocoena phocoena): Implications for conservational status assessment of populations
Longitudinal data on individual growth and seasonal changes in body mass, girth, and blubber thickness are rarely available for cetaceans, making it difficult to assess their population composition and individual nutritional condition. During different time intervals from 1997 to 2020, we collected longitudinal data on length, body mass, girth,and blubber thickness from seventeen harbour porpoises (Phocoena phocoena) in human care. We compared Gompertz and von Bertalanffy growth curves to collected length data at age 0–4 years for five individuals with known dates of birth. Von Bertalanffy had the lowest AICc value and was used to predict the birth year of twelve animals which age had previously been estimated based on tooth ring analysis and ossification of flipper bones. The growth curve was accurate within 1 yr. of age estimates. Within the first year, the calves grew 66%, attaining 84% of their adult length, and reached asymptotic length at age 3–4. For adults, there were large seasonal variations in body mass, body mass index, girth, and blubber thickness, with up to 28% of variation in body mass between seasons. We predicted individual body mass within ± 2 kg using measurements of length and girth, allowing estimation of body mass index of individuals with unknown mass. Our findings enable monitoring and assessments of population composition as well as nutritional condition of individual harbour porpoises, which is crucial for assessing conservational status and guiding management
Lenalidomide in combination with dexamethasone at first relapse in comparison with its use as later salvage therapy in relapsed or refractory multiple myeloma
This subset analysis of data from two phase III studies in patients with relapsed or refractory multiple myeloma (MM) evaluated the benefit of initiating lenalidomide plus dexamethasone at first relapse. Multivariate analysis showed that fewer prior therapies, along with β2-microglobulin (≤2.5 mg/L), predicted a better time to progression (TTP; study end-point) with lenalidomide plus dexamethasone treatment. Patients with one prior therapy showed a significant improvement in benefit after first relapse compared with those who received two or more therapies. Patients with one prior therapy had significantly prolonged median TTP (17.1 vs. 10.6 months; P=0.026) and progression-free survival (14.1 vs. 9.5 months, P=0.047) compared with patients treated in later lines. Overall response rates were higher (66.9% vs. 56.8%, P=0.06), and the complete response plus very good partial response rate was significantly higher in first relapse (39.8% vs. 27.7%, P=0.025). Importantly, overall survival was significantly prolonged for patients treated with lenalidomide plus dexamethasone with one prior therapy, compared with patients treated later in salvage (median of 42.0 vs. 35.8 months, P=0.041), with no differences in toxicity, dose reductions, or discontinuations despite longer treatment. Therefore, lenalidomide plus dexamethasone is both effective and tolerable for second-line MM therapy and the data suggest that the greatest benefit occurs with earlier use
Distribution, abundance and trends in abundance of fin and humpback whales in the North Atlantic
The North Atlantic Sightings Surveys (NASS) are a series of international cetacean line transect surveys, including participation from the Faroe Islands, Iceland, Norway and Spain, that have been conducted in 1987, 1989, 1995 and 2001. The NASS have covered a very large area of the central and eastern North Atlantic, from East Greenland east to coastal Norway, and from Svalbard south to the Iberian peninsula. The surveys used ships and aircraft as survey platforms. Target species were minke, fin and pilot whales, but all species encountered were registered. Here we present estimates of abundance for fin and humpback whales from the Northeast and Central portions of the survey area. The estimates are negatively biased because of whales diving during the passage of the survey platform and whales being missed by observers, but these and other potential biases are likely small for these species. Fin whales occurred in highest densities in Denmark Strait west of Iceland, while humpback whales were most abundant in shelf waters east and west of Iceland. The abundance of fin whales increased in the survey area over the period, with the greatest increase observed in the waters west of Iceland. There were 29,900 (cv 0.11) fin whales in the area in 2001. There has been a great increase in the abundance of humpback whales around Iceland, but not in other areas. Aerial surveys conducted in Icelandic coastal waters indicate an annual rate of increase of 15% in this area. There were 14,900 (cv 0.26) humpback whales in the entire survey area in 2001. The observed trends are consistent with increases in abundance following the cessation of whaling in this area, but the magnitudes of the observed increases, taken at face value, are greater than expected.. For humpback whales in particular, our recent estimates are substantially higher than some estimates of pre-whaling abundance. Other factors, including differential harvesting of sub-stocks, changes in carrying capacity, immigration from other areas, the near extirpation of some other cetacean species, and operational factors in the surveys themselves, may be involved
Introduction: The harbour seal (<i>Phoca vitulina</i>) - a global perspective
Introduction to Volume 8: Harbour seals in the North Atlantic and the Balti
Monitoring growth and energy utilisation of the harbour porpoise (<i>Phocoena phocoena</i>) in human care
Two harbour porpoises of an estimated age of 1-2 years were held in captivity from April 1997 and were still alive in April 2002, after rescue from pound nets set in inner Danish waters. They are presently housed in an outdoor penned-off area of Kerteminde fjord. Their growth (total body length, girth, body weight and blubber thickness) and daily dietary intake (weight of fish, dietary composition and energy value) have been monitored since capture. The general activity of the animals was regularly monitored, including two 24-hour long observation periods.
Initial body weights were 37.5 kg for Eigil (male) and 40.5 kg for Freja (female). Both porpoises lost 4 to 5 kg in the first few days because of their initial refusal to feed from the hand. Then body weight increased steadily reaching a peak of 44.75 kg for Eigil and 51.6 kg for Freja in early February 1998. A fluctuation in body weight with peaks of 44 to 45 kg for the male and 51to 56 kg for the female in winter followed by lows of 41 to 44 kg and 47 to 48 kg respectively in summer, established a clear pattern of seasonal fluctuation, mirrored by girth and blubber thickness variation. Length increased steadily from 130.5 cm to 139cm in Eigil, and from 127.5 cm to 150 cm in Freja. Food intake also fluctuated seasonally, and increases in food intake preceded weight gains. Daily food consumption in Eigil and Freja represented about 7 to 9.5% of body weight.
The growth of the animals resembles that of wild porpoises in the region. The sudden initial weight losses suggested that the energy reserves of the animals may only be short-term. The large weight increase in the winter months with colder water, correlating with the increase in girth and blubber thickness, suggest that energy reserves and blubber fat may be important for insulation. During the two 24-hour observations, the animals spent most of their time cruising around, although slow swimming and logging at the surface increased at night. Breathing rates were lower in the early morning hours, consistent with diminished activity. Both animals’ movements were influenced by external activities at poolside
A short review of the distribution of short-beaked common dolphins (Delphinus delphis) in the central and eastern North Atlantic with an abundance estimate for part of this area
This paper uses data from 3 programmes: (1) the North Atlantic Sightings Surveys (NASS) surveys undertaken throughout much of the central and eastern North Atlantic north of about 40° N in 1987, 1989, 1995 and 2001; (2) the MICA-93 programme; and (3) the north eastern Atlantic segment of the Small Cetacean Abundance in the North Sea (SCANS) survey in 1994. The data from all surveys were used to examine the distribution of common dolphins in the NE Atlantic. No sightings were made north of 57° N. An initial attempt to examine distribution against 4 potential non biological explanatory variables was made. A simple interpretation of the preliminary analyses presented here is that the primary areas for groups of common dolphins were in waters over 15° C and depths of 400-1,000 m (there does appear a link with shelf features), between around 49°-55° N especially between 20°-30°W. An illustrative example of spatial modelling is presented. Only for 1 year (and part of the total survey area) were there sufficient data to attempt to estimate abundance: 1995. The estimated abundance in the W Block of the NASS-95 Faroese survey was 273,159 (cv=0.26; 95% CI=153,392-435,104) short-beaked common dolphins. This estimate is corrected for animals missed on the trackline (g(0)) and for responsive movement
A short review of the distribution of short-beaked common dolphins (Delphinus delphis) in the central and eastern North Atlantic with an abundance estimate for part of this area
This paper uses data from 3 programmes: (1) the North Atlantic Sightings Surveys (NASS) surveys undertaken throughout much of the central and eastern North Atlantic north of about 40° N in 1987, 1989, 1995 and 2001; (2) the MICA-93 programme; and (3) the north eastern Atlantic segment of the Small Cetacean Abundance in the North Sea (SCANS) survey in 1994. The data from all surveys were used to examine the distribution of common dolphins in the NE Atlantic. No sightings were made north of 57° N. An initial attempt to examine distribution against 4 potential non biological explanatory variables was made. A simple interpretation of the preliminary analyses presented here is that the primary areas for groups of common dolphins were in waters over 15° C and depths of 400-1,000 m (there does appear a link with shelf features), between around 49°-55° N especially between 20°-30°W. An illustrative example of spatial modelling is presented. Only for 1 year (and part of the total survey area) were there sufficient data to attempt to estimate abundance: 1995. The estimated abundance in the W Block of the NASS-95 Faroese survey was 273,159 (cv=0.26; 95% CI=153,392-435,104) short-beaked common dolphins. This estimate is corrected for animals missed on the trackline (g(0)) and for responsive movement
Estimates of the abundance of minke whales (<i>Balaenoptera acutorostrata</i>) from Faroese and Icelandic NASS shipboard surveys
North Atlantic Sightings Surveys for cetaceans were carried out Northeast and Central Atlantic in 1987, 1989, 1995 and 2001. Here we provide estimates of density and abundance for minke whales from the Faroese and Icelandic ship surveys. The estimates are not corrected for availability or perception biases. Double platform data collected in 2001 indicates that perception bias is likely considerable for this species. However comparison of corrected estimates of densityfrom aerial surveys with a ship survey estimate from the same area suggests that ship surveys can be nearly unbiased under optimal survey conditions with high searching effort. There were some regional changes in density over the period but no overall changes in density and abundance. Given the recent catch history for minke whales in this area, we would not expect to see changes in abundance due to exploitation that would be detectable with these surveys