Australian sperm whales from different whaling stocks belong to the same population

1. Understanding the factors driving population structure in marine mammals is needed to evaluate the impacts of previous exploitation, current anthropogenic threats, conservation status, and success of population recovery efforts.
2. Sperm whales are characterized by a worldwide distribution, low genetic diversity, complex patterns of social and genetic structure that differ significantly within and between ocean basins, and a long history of being commercially whaled. In Australia, sperm whales from the (International Whaling Commission assigned) southern hemisphere ‘Division 5’ stock were very heavily exploited by whaling.
3. The present study assessed the potential effects of whaling on the genetic diversity of sperm whales in Australia and the population genetic structure of these whales within a global context. A combination of historical and contemporary sperm whale samples (n = 157) were analysed across six regions, from south-eastern Australia (‘Division 6’ stock in the Pacific Ocean) to south-western Australia (‘Division 5’ stock in the Indian Ocean).
4. Sperm whales sampled from the ‘Division 5’ and ‘Division 6’ stocks belong to the same population based on nuclear and mitochondrial DNA (mtDNA) analyses. Four novel sperm whale mtDNA haplotypes were identified in animals from Australian waters. Levels of genetic diversity were low in Australian sperm whales but were similar to those previously reported for populations in the Indian and Pacific Oceans.
5. Given the genetic distinctiveness of sperm whales in Australian waters from other regions in the Pacific and Indian Oceans, and the lack of recovery in population numbers, further scientific studies are needed to increase our understanding of population dynamics and the effectiveness of threat management strategies in this species.

     

Historical and contemporary habitat use of sperm whales around the Galápagos Archipelago: Implications for conservation

1. Sperm whales have occupied the waters off the Galápagos Islands, Ecuador, for at least the past 200 years. During the 19^th century, they were the target of intensive whaling that severely depleted the population. In recent times, after commercial whaling ended, sperm whales in the region remain vulnerable to multiple threats, especially potential entanglement in fishing gear, which may hinder their ability to recover from the whaling era.
2. As a highly mobile, long-lived species, long-term analysis of the habitat use of sperm whales is necessary to establish effective conservation and management strategies. Here, contemporary (1985–2014) and historical (1830–1850) sperm whale habitat use off the Galápagos Islands was analysed and contrasted to the extent of the Galápagos Marine Reserve (GMR). Contemporary habitat use and its variability over time were modelled as a function of geographic, oceanographic, and topographic variables using generalized additive models.
3. The fine-scale habitat (<50 km) used by sperm whales was associated with topographic (i.e. depth and slope) and oceanographic characteristics (i.e. relative sea surface temperature and standard deviation of sea surface temperature), but these preferences varied over time.
4. While historical and contemporary data indicate that sperm whale habitat primarily occurred within the boundaries of the GMR, in recent years, whales were found up to 30.1% of the time outside the GMR, potentially overlapping with commercial fisheries operating in the area.
5. The dynamic nature of the relationship of this nomadic species with its habitat highlights the need of large-scale conservation efforts across the Eastern Tropical Pacific region, including the wide-scale enforcement of regulations requiring the use of Automatic Identification System in fishing vessels, the promotion of on-board fisheries observer programmes, the development of adaptive management strategies, and international collaboration to identify and mitigate threats.

     

New urban habitat for endangered humpback whales: San Francisco Bay

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Sperm whales associated with Gulf Stream features off the north-eastern USA shelf

Marine mammal surveys were conducted during sum Mer 1990 and 1991 in shelf-edge and off-shelf waters between Cape Hatteras and Georges Bank. Sperm whales were the most frequently sighted large whale in both years, constituting 27.9% and 12.7% of total sightings in 1990 and 1991, respectively. Sighting rates of sperm whales that were within a 9.3 km buffer (5 n.m.) of the Gulf Stream north wall were not significantly different (x²= 2.86, P > 0.05) from those within the Gulf Stream during 1990. In 1991, however, significantly more (x²= 51.0, P < 0.05) sightings were associated with shelf-edge areas where warm core rings were located.     

From whaling to whale watching: Identifying fin whale critical foraging habitats off the Chilean coast

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Seasonal acoustic occurrence of blue,fin, and North Atlantic right whales in the New York Bight

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Potential ship strikes and density of humpback whales in the Abrolhos Bank breeding ground,Brazil

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Longer migration not necessarily the costliest strategy for migrating humpback whales

1. Long‐distance migration is a demanding physical activity, and how well animals manage the associated costs will have important implications for their fitness.
2. The Oceania humpback whale (Megaptera novaeangliae) population is recovering from past exploitation markedly slower than the neighbouring east Australian whales. The reasons for this are unknown, although higher energetic costs of longer migratory distances could be a possible explanation. Due to their fully aquatic lives, studying the energy expenditure of these large animals requires methods that do not rely on capturing the animal, such as bioenergetic models.
3. A state‐space model was fitted to satellite data to infer behavioural states for southern migrating whales. Travel speeds and behavioural states were used in a bioenergetic model to estimate the energetic cost of the migration phase. Relative differences in average duration, distance, and energetic costs were compared between migratory routes and distances.
4. Total energy used during migration was a trade‐off between cost of transport (determined by travel speed) and daily maintenance (determined by daily basal metabolic costs). Oceania whales migrating to the Amundsen and Bellingshausen Seas travelled fastest and furthest, 15 and 21% further than whales migrating to the d'Urville Sea (east Australian whales) and Ross Sea, respectively. Therefore, they had the highest cost of transport, 25 and 85% higher than for d'Urville Sea and Ross Sea whales, respectively. However, energy saved in terms of daily maintenance by using fewer days to complete a longer migration resulted in only a 6–7% increase in total energetic cost.
5. The results highlight that travelling further does not necessarily translate into an increase in total energy expenditure for migratory whales, since they can compensate for longer distance by travelling faster. Further research on the energetics of different whale populations could provide insight into the productivity of Southern Ocean feeding regions and help understand the environmental and anthropogenic effects on the whales' energy budgets.

     

Perception of a cetacean mass stranding in Italy: the emergence of compassion

• 1 The view that whales are malicious monsters has been pervasive throughout history. Conversely, the idea that these animals experience suffering has emerged only recently. One way of investigating perceptual, as well as behavioural, shifts is assessing general public reactions to mortality events involving wild, rare and charismatic animals.
• 2 Here, the responses of 118 individuals to questions regarding the mass stranding of seven sperm whales (Physeter macrocephalus) along the Adriatic Sea coast of Italy in December 2009 are reported through interviews taken at the stranding site and in the direct proximity of the dead animals.
• 3 When asked why the whales were stranded, 44.1% of the respondents suggested anthropogenic causes and 21.2% non‐anthropogenic. The remaining 34.7% mentioned a generic ‘disorientation’ or stated they did not know. When asked how they felt about the whales, 68.6% expressed feelings of compassion or care towards the animals. Clearly non‐compassionate attitudes accounted for only 4.1% of the sample. Finally, 21.2% expressed feelings that were ambiguous in terms of being suggestive of compassionate or non‐compassionate attitudes, including 11.9% amazement, 4.2% deprecation and 5.1% powerlessness.
• 4 These results are in stark contrast with information obtained from accounts of similar events that have occurred in historical times, up until the first half of the 20th century. For centuries, responses to cetacean live strandings—typically including killing and harming of the animals—were either utilitarian or characterized by feelings including fear and a desire to ‘subjugate the beast’, with no apparent concern for their suffering and death.
• 5 It is concluded that attitudes towards whales—today strikingly revolving around sadness, compassion and a sense of loss—have changed dramatically over time, with a steep turnaround in the 1970/1980s. Full appreciation of the ongoing evolution in public perception can channel marine conservation efforts and assist in the design of response strategies to marine mammal strandings. Copyright © 2010 John Wiley & Sons, Ltd.

     

From land and sea,long‐term data reveal persistent humpback whale (Megaptera novaeangliae) breeding habitat in New Caledonia

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First evidence of bubble-net feeding and the formation of ‘super-groups’ by the east Australian population of humpback whales during their southward migration

1. The recovery of overexploited populations is likely to reveal behaviours that may have been present prior to harvest but are only now reappearing as the population size increases. The east Australian humpback whale (Megaptera novaeangliae) population (group V, stock E1) has recovered well from past exploitation and is now estimated to be close to the pre-whaling population size.
2. Humpback whales were thought to follow a ‘feast and famine’ model historically, feeding intensively in high-latitude feeding grounds and then fasting while migrating and in calving grounds; however, there is growing evidence that animals may feed outside of known foraging grounds.
3. This short article reports on the first photographically documented evidence of bubble-net feeding by humpback whales in Australian coastal waters (n = 10 groups observed) and provides the first evidence of a second site in the southern hemisphere for the formation of ‘super-groups’ (n = 6 super-groups at discrete locations).
4. The formation of super-groups may be linked to changes in the type or density of prey available, either along the migratory route or in the feeding grounds of the previous summer. It is also possible that the increased population size following recovery make large group sizes while feeding more common. These findings strongly support evidence that feeding behaviour is not restricted to high-latitude foraging grounds in the Southern Ocean, and that prey consumption prior to leaving the coastal waters of Australia may be a significant component of the migratory ecology of this population.
5. Understanding how environmental variation influences the extent to which humpback whales depend on foraging opportunities along their migratory route, and where feeding occurs, will help to predict how future changes in the ocean will influence whale populations. This will also allow for more effective management measures to reduce the impact of threats during this important period of energy consumption.

     

Refrigerated storage and cryopreservation of sperm of red drum, Sciaenops ocellatus L.

To aid in artificial spawning of sciaenid fishes, the present authors developed techniques to collect, handle and cryopreserve sperm from red drum, Sciaenops ocellatus L. Sperm were collected by removing and slicing the testis, and adding Hanks' balanced salt solution (HBSS) or NaCl solution (each at 200-400 mOsm kg^?1) as an extender. Sperm were activated with 800 mOsm kg^?1 artificial sea water (ASW) to characterize motility. Sperm reached maximum motility (highest percentage motility observed for that sample) within 8 ± 1 s (mean ± SD) and remained at maximum motility for 33 ± 4 s. Sperm were exposed to graded osmotic pressures of ASW (8-800 mOsm kg^?1) to determine the range of osmolalities that elicited motility. Threshold activation (defined as ～10% motility) occurred at 351 ± 4 mOsm kg^?1 and complete activation occurred at 539 ± 2 mOsm kg^?1. Sperm stored at 200 mOsm kg^?1 retained motility for up to 13 days. Dimethyl sulphoxide (DMSO) was used as a cryoprotectant at concentrations ranging from 7.5% to 15% (v:v) in HBSS (200 mOsm kg^?1). There were no significant differences among post-thaw motilities of sperm cryopreserved at any concentration of DMSO. Sperm thawed on the benchtop at 21°C had lower post-thaw motility than did sperm thawed at 10, 20, 30, 40, 50 or 60°C in a water bath.     

Site fidelity and movement patterns of short‐finned pilot whales within the Canary Islands: Evidence for resident and transient populations

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Bryde's whales in the North-East Atlantic: New insights on site fidelity and connectivity between oceanic archipelagos

1. The conservation of marine megafauna presents numerous difficulties owing to their high mobility over difficult-to-access oceanic areas that impairs the collection of basic, but essential, biological information.
2. The Bryde's whale (Balaenoptera edeni) is one of the most elusive species of baleen whales, and although it is known to be a seasonal visitor to several archipelagos in Macaronesia (the Azores, Madeira, and Canaries), there are no studies regarding its occurrence or geographical connectivity in this area of the Atlantic.
3. A 14-year photographic database was used to determine short-term (intra-seasonal) and long-term (inter-annual) Bryde's whale site fidelity and to estimate individual residency times in Madeira, whereas photographic catalogues from Madeira and the Canaries were compared in order to assess large-scale movements (i.e. on the scale of hundreds of kilometres).
4. In Madeira, 59 individuals were identified, 27 (45.8%) of which were recaptured. Of these, 10 individuals (37.0%) presented short-term site fidelity and 17 individuals (63.0%) presented long-term site fidelity, with a maximum recapture interval of 12 years. Lagged identification rates showed that five individuals (SE = 2) remained in the area for 32 days (SE = 108 days) before leaving and not returning during the same year. Seven individuals were seen both in Madeira and the Canaries (catalogue comprising 51 individuals), three of which were identified multiple times in both archipelagos, with a minimum of 43 days between consecutive sightings.
5. This information combined with the fact that this species is commonly sighted accompanied by calves and feeding in both archipelagos highlights the ecological importance of this area for Bryde's whales. This should be taken into consideration by policymakers when implementing conservation measures, where coordination of effort among countries is needed. This study also reinforces the value of using data from platforms of opportunity and of making photographic data open access.

     

Identifying important habitat for northern bottlenose and Sowerby's beaked whales in the western North Atlantic

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Seasonal changes in sperm production and quality in the red porgy Pagrus pagrus (L.)

Cultured red porgy Pagrus pagrus (L.) males (n=6) were sampled every 2 weeks for milt, in order to monitor changes in sperm quality parameters during a whole spawning period. On 11 January 2001, 60% of the fish were spermiating, increasing to 100% in mid‐February and dropping to 30% by mid‐April. Sperm density showed a slight increasing trend, with mean values ranging between 8.6 and 23.7×10⁹ spermatozoa mL^?1. Sperm motility percentage exhibited a significant improvement during the spawning season (analysis of variance (anova ) P=0.0001). The duration of forward motility for the major part of the monitoring period ranged between 2 and 4 min. Red porgy spermatozoa maintained their viability for many days after whole storage of milt at 4°C. During the monitoring period there were significant changes in the mean duration of sperm survival after cold storage, ranging from 5 to 12 days. The total volume of expressible milt was maximal on 28 March, increasing from a mean value of 1.7 mL to 5.3 mL kg^?1. Milt production of captive‐reared red porgy does not appear to be limiting, when compared with the volume of expressible milt produced by other cultured marine fishes.     

Effects of whale watching on the activity budgets of humpback whales,Megaptera novaeangliae (Borowski, 1781), on a feeding ground

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Sperm quality in male <Emphasis Type="Italic">Barbus barbus</Emphasis> L. fed different diets during the spawning season

Sperm quality of Barbus barbus L. was compared among the three following dietary regimes: Group A, fed 100% commercial diet (Karpico™ containing 33% crude protein and 6% fat), Group B, fed 78% commercial diet and 22% frozen chironomid (Chironomus plumosus) larvae, and Group C, fed 56% commercial diet and 44% frozen chironomid larvae. Concentrations of polyunsaturated fatty acids (PUFAs) in Group A, B, and C were 39.1, 42.0, and 44.6, respectively, as a percentage of total fatty acids. Sperm morphology, volume, concentration and motility, total number of spermatozoa, and osmolality of the seminal plasma were compared during the spawning season. Dietary regime did not influence sperm volume, concentration, or total number of spermatozoa, osmolality of seminal plasma, or the percentage of motile sperm, but significantly affected sperm morphology (except for anterior and posterior parts of the midpiece) and sperm velocity (P < 0.05). Groups B and C showed similar sperm characteristics during the spawning season compared to Group A. Almost all parameters changed either among or within groups during the spawning season, suggesting differences in terms of the optimal time for sperm collection. The best time for sperm collection was March for Group A, but April for Groups B and C, when the osmolality of the seminal plasma measured 289 mOsmol kg⁻¹ and sperm motility was maximal. Spermatogenesis, hydration, and cell decomposition were confirmed as the three major parameters controlling sperm characteristics during the spawning season. The possible correlation between sperm morphology and motility requires further study.     

High mortality of adult female Magellanic penguins by gillnet fisheries in southern Brazil

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Effect of type of bait on pelagic longline fishery–loggerhead turtle interactions in the Gulf of Gabes (Tunisia)

• 1. Sea turtles may migrate vast distances from their feeding areas to home rookeries where they nest. During these migrations sea turtles are subject to many threats, among which are interactions with pelagic longlines.
• 2. This gear is used frequently in the summer period in the Gulf of Gabes targeting mainly the sandbar shark (Carcharhinus plumbeus). Hooks are baited with mackerel (Scomber scombrus) or pieces of stingray (Dasyatis pastinaca).
• 3. Twenty‐one fishing trips (48 sets with a total of 35 950 hooks deployed) were conducted using onboard observers in the south of the Gulf of Gabes during the months of July, August and September in 2007 and 2008. Stingray and mackerel bait were used in 19 and 29 sets, respectively.
• 4. In total, 29 loggerhead sea turtles (Caretta caretta) were captured; the majority of them were juvenile and active. Turtles were caught at a statistically greater frequency on sets with hooks baited with mackerel than on sets with hooks baited with pieces of stingray.
• 5. The type of bait also affected the catch of the target species by increasing the efficiency when pieces of stingrays were used.
• 6. These results encourage further research into new baits to mitigate turtle catch by longline fisheries without affecting the catch of target species. Copyright © 2010 John Wiley & Sons, Ltd.