Cetacean sightings and strandings: evidence for spatial and temporal trends?

2011 ◽  
Vol 92 (8) ◽  
pp. 1809-1820 ◽  
Author(s):  
Stephen K. Pikesley ◽  
Mathew J. Witt ◽  
Tom Hardy ◽  
Jan Loveridge ◽  
Jeff Loveridge ◽  
...  
Keyword(s):  
Bottlenose Dolphin ◽  
Temporal Trends ◽  
Minke Whale ◽  
Harbour Porpoise ◽  
Mitigation Strategies ◽  
North Coast ◽  
Positive Trend ◽  
Common Dolphin ◽  
Cetacean Species ◽  
Key Species

Cetacean species and their habitats are under threat and effective marine management mitigation strategies require knowledge and understanding of cetacean ecology. This requires data that are challenging and expensive to obtain; incidental sightings/strandings data are potential underused resources. In this study, incidental cetacean sightings (N = 6631) and strandings (N = 1856) in coastal waters of Cornwall, south-west Britain (1991 to 2008) were analysed for evidence of spatial and temporal patterns or trends. Eighteen species were recorded sighted and/or stranded; key species were identified as bottlenose dolphin (Tursiops truncatus), harbour porpoise (Phocoena phocoena), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus) and minke whale (Balaenoptera acutorostrata). There were significant decreases in bottlenose dolphin sightings and pod size but an increase in harbour porpoise and minke whale sightings. Cetacean strandings showed a recent decrease over time although there was a significant positive trend in harbour porpoise strandings that correlated with sightings. Incidence of sightings and strandings were both greater on the south coast than the north coast. When Marine Tour Operator data were analysed, distinct species-specific inshore and offshore habitat use was evident. With rigorous interrogation and editing, significant patterns and trends were gained from incidentally collected data, highlighting the importance of public engagement with such recording schemes and the potential of these underused resources.

A survey of public awareness of the occurrence and diversity of cetaceans in south-west Scotland

2004 ◽  
Vol 84 (5) ◽  
pp. 1101-1104 ◽  
Author(s):  
N.J. Scott ◽  
E.C.M. Parsons
Keyword(s):  
Bottlenose Dolphin ◽  
Public Awareness ◽  
Minke Whale ◽  
Harbour Porpoise ◽  
Common Dolphin ◽  
Cetacean Species ◽  
The Public ◽  
South West ◽  
Tourism Professionals ◽  
Level Of Knowledge

In summer 2001, members of the public in south-west Scotland were interviewed to determine their knowledge of the diversity and occurrence of cetaceans in the region. Interviews were conducted in both rural island and coastal communities and a major city.The majority of interviewees (46%) underestimated the number of cetacean species occurring in western Scottish waters (i.e. <10 species). Only 4·4% gave the correct answer (24). Location of the participant affected the level of knowledge. Photographs were presented of the four most commonly occurring cetacean species: only 30·2% correctly identified one or more of the species. The species most frequently identified correctly was the bottlenose dolphin (19% of interviewees) followed by the harbour porpoise (17·5%), minke whale (10·7%) and, lastly, the common dolphin (7·1%).Interviewees were also asked whether certain cetacean species occurred in local waters or not. The level of awareness was generally low. The most common positive answers involved the bottlenose dolphin, harbour porpoise, and minke whale. Only one in five were aware of killer whales and 13·1% believed that grey whales occurred in Scottish waters. Knowledge of species occurrence showed statistically significant relationships with age, gender, level of environmental interest and location, but not occupation (teachers, tourism professionals and marine stakeholders did not show greater levels of cetacean knowledge). The study identified target groups and locations where knowledge of cetaceans is low and environmental education efforts should be concentrated.

Do abundance–occupancy relationships exist in cetaceans?

2010 ◽  
Vol 90 (8) ◽  
pp. 1571-1581 ◽  
Author(s):  
Karen Hall ◽  
Colin D. MacLeod ◽  
Laura Mandleberg ◽  
Caroline M. Schweder-Goad ◽  
Sarah M. Bannon ◽  
...  
Keyword(s):  
Relative Density ◽  
Protected Areas ◽  
General Rule ◽  
Noise Pollution ◽  
Average Density ◽  
Minke Whale ◽  
Harbour Porpoise ◽  
Common Dolphin ◽  
Cetacean Species ◽  
Density Index

A positive relationship between the number of locations where a species occurs and the average density of individuals across those locations has been found in a wide variety of taxa and has been described as one of the most general and widespread relationships in macro-ecology. However, exceptions to this general rule have been found and this study tested whether abundance–occupancy relationships exist within the cetacean community of the west coast of Scotland. Data were collected in 2003–2006 and occupancy rates were calculated and compared to two density indices (relative density of groups per km2 surveyed and relative density of individuals per km2 surveyed) for four cetacean species (harbour porpoise, bottlenose dolphin, common dolphin and minke whale). Significant positive intraspecific abundance–occupancy relationships were found for both relative density of groups per km2 and relative density of individuals per km2 for two out of the four cetacean species tested (harbour porpoise and minke whale). When the relationships between the different species were compared, all four were found to conform to the same interspecific relationship when relative density of groups was used as the density index. However, some species were found to conform to different relationships when relative density of individuals was used as the density index, potentially due to differences in social structure between cetacean species. These relationships mean that when cetaceans are at a higher density within an area, they also occupy a greater number of locations and vice versa. The existence of positive abundance–occupancy relationships in cetaceans has a number of potential implications for their conservation and management. In particular, it means that when a potential impact is likely to positively or negatively affect the size of the range of a species or population, such as noise pollution or climate change, it is likely to also affect the species' or population's abundance in the same direction. It also has implications for the design and extent of protected areas, such as marine protected areas; as such relationships could be used to determine the area required to maintain a viable population size.

Spatial and temporal trends in the distribution of harbour porpoises, white-beaked dolphins and minke whales off Aberdeenshire (UK), north-western North Sea

2007 ◽  
Vol 87 (1) ◽  
pp. 327-338 ◽  
Author(s):  
Caroline R. Weir ◽  
Karen A. Stockin ◽  
Graham J. Pierce
Keyword(s):  
North Sea ◽  
Survey Methods ◽  
Temporal Trends ◽  
Harbour Porpoise ◽  
Breeding Habitat ◽  
Balaenoptera Acutorostrata ◽  
Cetacean Species ◽  
Minke Whales ◽  
Spatial And Temporal Trends ◽  
Strong Seasonality

Most North Sea cetacean species are wide-ranging and consequently poorly studied. Spatial and temporal trends in the distribution of the harbour porpoise Phocoena phocoena, white-beaked dolphin Lagenorhynchus albirostris, and minke whale Balaenoptera acutorostrata were assessed at a coastal North Sea study area in Aberdeenshire, Scotland. Between March 1999 and October 2001, cetacean data were collected using both land- and vessel-based survey methods. A total of 174 sightings of these three cetacean species was recorded during approximately 330 h of combined survey effort (228 h land-based and 102 h vessel-based). Harbour porpoises were present throughout the year with peak occurrence during August and September. The presence of white-beaked dolphins and minke whales was strictly seasonal, with a peak in occurrence during August. The fine-scale distribution of all three species varied within the study area, with an apparent preference for sections of coast adjacent to deeper water. Most porpoise calves and juveniles were recorded between June and September, when 35% of harbour porpoise groups contained immature animals. The proportion of calves amongst porpoise sightings was higher during June than any other month. White-beaked dolphin calves were present in 32% of groups, and occurred in all three months that the species was recorded. Group size was higher in white-beaked dolphin pods containing immature animals. The strong seasonality in occurrence of all three species may relate to requirements for breeding habitat, movements of shared prey species and/or inter-specific competition with other species.

scholarly journals Patterns and Trends in Cetacean Occurrence Revealed by Shorewatch, a Land-Based Citizen Science Program in Scotland (United Kingdom)

2021 ◽  
Vol 8 ◽  
Author(s):  
Paula Gutiérrez-Muñoz ◽  
Alice E. M. Walters ◽  
Sarah J. Dolman ◽  
Graham J. Pierce
Keyword(s):  
United Kingdom ◽  
Citizen Science ◽  
West Coast ◽  
Bottlenose Dolphin ◽  
Minke Whale ◽  
Additive Models ◽  
Harbor Porpoise ◽  
The West ◽  
Cetacean Species ◽  
Risso's Dolphin

Shorewatch is a citizen science project, managed by Whale and Dolphin Conservation (WDC), that records the occurrence of cetaceans during regular, standardized watches from a series of locations along the coast of Scotland (United Kingdom). Observer training and a clearly defined protocol help deliver a valuable source of information about cetacean occurrence and activity along the coast. Between 2005–2018, over 52000 watches generated over 11000 sightings of at least 18 cetacean species. Generalized Additive Models based on sightings for the five most commonly sighted species (bottlenose dolphin, harbor porpoise, minke whale, Risso’s dolphin, and common dolphin), at those sites with the longest time series, demonstrated seasonal, geographical and year-to-year differences in their local occurrence and relative abundance. Bottlenose dolphins are mainly present at observation sites located on the east coast of Scotland, being uncommon on the west coast, while harbor porpoise and minke whale are principally present at sites located on the west coast. The seasonality observed in cetacean occurrence is consistent with peak abundance in summer months described by previous studies in the area. Mean depth around the observation sites is the static variable that apparently has the greatest influence on species presence and number of sightings, except for Risso’s dolphin. All the species except bottlenose dolphin showed upward trends in occurrence and number of sightings over the period 2012–2018. Evidence of temporal autocorrelation was found between results from consecutive watches at the same site on the same day as well as between results from consecutive days at the same site. The power to detect declines in local abundance over a 6-year period depends on the underlying sighting rate of each cetacean species, the number of watches performed and the rate of decline. Simulations performed to determine the power to detect a decline suggest that the current intensity of observation effort in some observation sites, of about 2500 watches per year, may offer good prospects of detecting a 30% decline of the most frequently sighted species (95% of the time) over a 6-year period, although a more even distribution of observation effort in space and time is desirable. The data could potentially be used for monitoring and 6-yearly reporting of the status of cetacean populations.

scholarly journals Seasonal dynamics of occurrence and group size of three species of cetaceans (Delphinidae and Phocoenidae) on the southwestern coast of the Black Sea

2020 ◽  
Vol 84 (4) ◽  
pp. 431-439
Author(s):  
Nastassia Uluduz ◽  
Alexey Yanchukov ◽  
Mustafa Sözen
Keyword(s):  
Group Size ◽  
Black Sea ◽  
Seasonal Dynamics ◽  
Prey Availability ◽  
Early Summer ◽  
Harbour Porpoise ◽  
The Black Sea ◽  
Common Dolphin ◽  
Cetacean Species ◽  
Fish Prey

The spatial and temporal occurrence of cetaceans in the Black Sea and particularly along its southwestern coastline is poorly studied. Based on a total of 609 encounters, we present the analysis of monthly dynamics of (1) the numbers of cetacean sightings and (2) their group size for all three Black Sea cetacean species: the bottlenose dolphin (Tursiops truncatus), the short-beaked common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) over a continuous period of 29 months (January 2018 - May 2020) from two fixed coastal observation points near the city of Zonguldak, Turkey. Seasonal fluctuations were found in the occurrence of all three species, with peaks in April-May (spring). Similarly, the largest groups of P. phocoena and T. truncatus were recorded in the late spring and early summer period, while D. delphis had a peak in July (summer). In case of the harbour porpoise, we speculate that these variations can be explained by the annual migrations from the northwestern to southern waters of the Black Sea, while the seasonal dynamics of the two Delphinidae species might depend on fish prey availability. While our data were collected locally, the results provide better insight into the ecology of cetaceans within the entire Black Sea.

scholarly journals Cetaceans observed in Suriname and adjacent waters

2015 ◽  
Vol 10 (1) ◽  
pp. 2-19 ◽  
Author(s):  
Marijke Nita De Boer
Keyword(s):  
Bottlenose Dolphin ◽  
Sperm Whale ◽  
Seismic Survey ◽  
Marine Biodiversity ◽  
Common Dolphin ◽  
Cetacean Species ◽  
Spotted Dolphin ◽  
Common Bottlenose Dolphin ◽  
Delphinus Capensis ◽  
Guiana Dolphin

Very little information exists about the cetaceans in the Guianas: Suriname and its neighboring countries Guyana and French Guiana. During a dedicated cetacean survey carried out from a geophysical seismic survey vessel in the offshore waters of Suriname (May-September 2012), the occurrence of 13 cetacean species was documented and of those, 11 were newly documented for this area. The species observed by the author included sperm whale (Physeter macrocephalus), Bryde’s whale (Balaenoptera edeni), false killer whale (Pseudorca crassidens), melon-headed whale (Peponocephala electra), roughtoothed dolphin (Steno bredanensis), long-beaked common dolphin (Delphinus capensis), Fraser’s dolphin (Lagenodelphis hosei), pantropical spotted dolphin (Stenella attenuata) and spinner dolphin (Stenella longirostris). During transit to the survey area (Trinidad to Suriname) incidental sightings were recorded which included common bottlenose dolphin (Tursiops truncatus) off Trinidad, Stenella sp. off Guyana and Guiana dolphin (Sotalia guianensis) at the entrance of the Suriname River. Opportunistic records originating from the periods December 2008-March 2009 and August-October 2012 were forwarded to the author. These records included common bottlenose dolphin, Atlantic spotted dolphin (Stenella frontalis) and short-finned pilot whale (Globicephala macrorhynchus). There is a growing need to identify critical areas for marine biodiversity conservation, both locally and regionally. This paper describes the general occurrence of the cetacean community encountered in Suriname waters in summer. The study revealed that the offshore cetacean community in Suriname is best described as primarily a tropical community, dominated by odontocetes (dolphins and sperm whales). Although the species diversity was relatively high, the overall cetacean relative abundance index (number of animals per 100km effort) was low, which is consistent for tropical equatorial offshore waters. Apart from the sperm whale and the Guiana dolphin, all the other species recorded represent new species records for Suriname. It is recommended that more continuous monitoring in different seasons be carried out in order to gain a better understanding of the occurrence, distribution and status of the different cetacean species within the region. 

First record of Norwegian killer whales attacking and feeding on a harbour porpoise

2015 ◽  
Vol 8 ◽  
Author(s):  
A. Mel Cosentino
Keyword(s):  
North Atlantic ◽  
Marine Mammals ◽  
First Record ◽  
Harbour Porpoise ◽  
Sperm Whales ◽  
Killer Whales ◽  
Strait Of Gibraltar ◽  
Cetacean Species ◽  
The North ◽  
Northern Bottlenose Whales

Orcinus orcais a cosmopolitan species and the most widely distributed marine mammal. Its diet includes over 140 species of fish, cephalopods, sea birds and marine mammals. However, many populations are specialised on certain specific prey items. Three genetically distinct populations have been described in the North Atlantic. Population A (that includes the Icelandic and Norwegian sub-populations) is believed to be piscivorous, as is population C, which includes fish-eating killer whales from the Strait of Gibraltar. In contrast, population B feeds on both fish and marine mammals. Norwegian killer whales follow the Norwegian spring spawning herring stock. The only description in the literature of Norwegian killer whales feeding on another cetacean species is a predation event on northern bottlenose whales in 1968. Daily land-based surveys targeting sperm whales were conducted from the Andenes lighthouse using BigEyes®binoculars (25×, 80 mm). The location of animals at sea was approximated through the use of an internal reticule system and a graduated wheel. On 24 June 2012 at 3:12 am, an opportunistic sighting of 11 killer whales was made off Andenes harbour. The whales hunted and fed on a harbour porpoise. Despite these species having overlapping distributions in Norwegian waters, this is the first predatory event reported in the literature.

scholarly journals Trends and Inequalities in the Incidence of Acute Myocardial Infarction among Beijing Townships, 2007–2018

2021 ◽  
Vol 18 (23) ◽  
pp. 12276
Author(s):  
Jie Chang ◽  
Qiuju Deng ◽  
Moning Guo ◽  
Majid Ezzati ◽  
Jill Baumgartner ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Urban Areas ◽  
Disease Surveillance ◽  
Temporal Trends ◽  
Relative Increase ◽  
Mitigation Strategies ◽  
Middle Aged ◽  
Geographic Variations ◽  
Cross Sectional

Acute myocardial infarction (AMI) poses a serious disease burden in China, but studies on small-area characteristics of AMI incidence are lacking. We therefore examined temporal trends and geographic variations in AMI incidence at the township level in Beijing. In this cross-sectional analysis, 259,830 AMI events during 2007–2018 from the Beijing Cardiovascular Disease Surveillance System were included. We estimated AMI incidence for 307 consistent townships during consecutive 3-year periods with a Bayesian spatial model. From 2007 to 2018, the median AMI incidence in townships increased from 216.3 to 231.6 per 100,000, with a greater relative increase in young and middle-aged males (35–49 years: 54.2%; 50–64 years: 33.2%). The most pronounced increases in the relative inequalities was observed among young residents (2.1 to 2.8 for males and 2.8 to 3.4 for females). Townships with high rates and larger relative increases were primarily located in Beijing’s northeastern and southwestern peri-urban areas. However, large increases among young and middle-aged males were observed throughout peri-urban areas. AMI incidence and their changes over time varied substantially at the township level in Beijing, especially among young adults. Targeted mitigation strategies are required for high-risk populations and areas to reduce health disparities across Beijing.

scholarly journals Space–time clustering and temporal trends of hospitalizations due to pulmonary tuberculosis: potential strategy for assessing health care policies

2020 ◽  
Author(s):  
João Almeida Santos ◽  
Danielle T Santos ◽  
Ricardo A Arcencio ◽  
Carla Nunes
Keyword(s):  
Pulmonary Tuberculosis ◽  
Hospital Admissions ◽  
Temporal Trends ◽  
Space Time ◽  
Public Hospitals ◽  
Percentage Change ◽  
Ambulatory Setting ◽  
Spatial And Temporal Variation ◽  
Positive Trend ◽  
Annual Percentage Change

Abstract Background Tuberculosis (TB) causes pressure on healthcare resources, especially in terms of hospital admissions, despite being considered an ambulatory care-sensitive condition for which timely and effective care in ambulatory setting could prevent the need for hospitalization. Our objectives were to describe the spatial and temporal variation in pulmonary tuberculosis (PTB) hospitalizations, identify critical geographic areas at municipality level and characterize clusters of PTB hospitalizations to help the development of tailored disease management strategies that could improve TB control. Methods Ecologic study using sociodemographic, geographical and clinical information of PTB hospitalization cases from continental Portuguese public hospitals, between 2002 and 2016. Descriptive statistics, spatiotemporal cluster analysis and temporal trends were conducted. Results The space–time analysis identified five clusters of higher rates of PTB hospitalizations (2002–16), including the two major cities in the country (Lisboa and Porto). Globally, we observed a −7.2% mean annual percentage change in rate with only one of the identified clusters (out of six) with a positive trend (+4.34%). In the more recent period (2011–16) was obtained a mean annual percentage change in rate of −8.12% with only one cluster identified with an increase trend (+9.53%). Conclusions Our results show that space–time clustering and temporal trends analysis can be an invaluable resource to monitor the dynamic of the disease and contribute to the design of more effective, focused interventions. Interventions such as enhancing the detection of active and latent infection, improving monitoring and evaluation of treatment outcomes or adjusting the network of healthcare providers should be tailored to the specific needs of the critical areas identified.

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