scholarly journals An increase in detection rates of the critically endangered Baltic Proper harbor porpoise in Swedish waters in recent years

Author(s):  
Kylie Owen ◽  
Martin Sköld ◽  
Julia Carlström
2021 ◽  
Vol 8 ◽  
Author(s):  
Ida Carlén ◽  
Laetitia Nunny ◽  
Mark P. Simmonds

The conservation of harbor porpoises (Phocoena phocoena) appears to be failing in Europe. There are particular concerns about this species in the Baltic Proper, Black, and Mediterranean Seas, as well as in the Northeast Atlantic, including the Iberian population, off the Spanish and Portuguese coasts. The Baltic Proper porpoise is “critically endangered,” with a population only in the low hundreds, and the Scientific Committee of the International Whaling Commission has repeatedly called for action to ensure its survival. In 2020, the Committee issued a series of recommendations relating to it and the Iberian population. Similarly, the Black Sea harbor porpoise, Phocoena phocoena ssp. relicta, is classified by the IUCN as endangered. Another population which may be genetically distinct is the West Greenland harbor porpoise, which is hunted without quotas or close seasons. European cetaceans and their habitats are covered by a number of international and regional conventions and agreements and, under European Union law, are “highly protected.” In practice, however, these legal protections have failed to generate effective conservation. For example, Special Areas of Conservation (SACs) are required for them and, although sites have been designated in some marine areas/countries, in the absence of appropriate management plans, SACs cannot be expected to help improve the harbor porpoise's conservation status. Compared to many other species, porpoises are relatively long-lived with low reproductive capacity and only poor public recognition. Conservation and management efforts are caught up in a complicated nexus of interactions involving a web of commitments under international conventions and agreements, European environmental laws, and European fisheries policy. However, public disinterest, lack of political will to implement conservation measures, and complicated fishing-related issues hinder any real progress. More positively, recent advice from the International Council for the Exploration of the Seas (ICES) provides a new scientific foundation for conservation action to address fisheries bycatch in the Baltic Proper harbor porpoise population. Populations of other porpoise species (family Phocoenidae) are also threatened, most notably the global population of the critically endangered vaquita, or Gulf of California porpoise (Phocoena sinus). The common threats and factors affecting porpoise populations are discussed and recommendations offered.


Author(s):  
Mats Amundin ◽  
Julia Carlström ◽  
Len Thomas ◽  
Ida Carlén ◽  
Jens Koblitz ◽  
...  

Knowing the abundance of a population is a crucial component to assess its conservation status and develop effective conservation plans. For most cetaceans, abundance estimation is difficult given their cryptic and mobile nature, especially when the population is small and has a transnational distribution. In the Baltic Sea, the number of harbour porpoises (Phocoena phocoena) has collapsed since the mid-20th century and the Baltic Proper harbour porpoise is listed as Critically Endangered by the IUCN; however, its abundance remains unknown. Here, one of the largest ever passive acoustic monitoring studies was carried out by eight Baltic Sea nations to estimate the abundance of the Baltic Proper harbour porpoise for the first time. By logging porpoise echolocation signals at 298 stations during May 2011-April 2013, calibrating the loggers’ spatial detection performance at sea, and measuring the click rate of tagged individuals, we estimated an abundance of 66-1,143 individuals (95% CI, point estimate 490) during May-October within the population’s proposed management border. The small abundance estimate strongly supports that the Baltic Proper harbour porpoise is facing an extremely high risk of extinction, and highlights the need for immediate and efficient conservation actions through international cooperation. It also provides a starting point in monitoring the trend of the population abundance to evaluate the effectiveness of management measures and determine its interactions with the larger neighbouring Belt Sea population. Further, we offer evidence that design-based passive acoustic monitoring can generate reliable estimates of the abundance of rare and cryptic animal populations across large spatial scales.


1993 ◽  
Vol 32 (02) ◽  
pp. 175-179 ◽  
Author(s):  
B. Brambati ◽  
T. Chard ◽  
J. G. Grudzinskas ◽  
M. C. M. Macintosh

Abstract:The analysis of the clinical efficiency of a biochemical parameter in the prediction of chromosome anomalies is described, using a database of 475 cases including 30 abnormalities. A comparison was made of two different approaches to the statistical analysis: the use of Gaussian frequency distributions and likelihood ratios, and logistic regression. Both methods computed that for a 5% false-positive rate approximately 60% of anomalies are detected on the basis of maternal age and serum PAPP-A. The logistic regression analysis is appropriate where the outcome variable (chromosome anomaly) is binary and the detection rates refer to the original data only. The likelihood ratio method is used to predict the outcome in the general population. The latter method depends on the data or some transformation of the data fitting a known frequency distribution (Gaussian in this case). The precision of the predicted detection rates is limited by the small sample of abnormals (30 cases). Varying the means and standard deviations (to the limits of their 95% confidence intervals) of the fitted log Gaussian distributions resulted in a detection rate varying between 42% and 79% for a 5% false-positive rate. Thus, although the likelihood ratio method is potentially the better method in determining the usefulness of a test in the general population, larger numbers of abnormal cases are required to stabilise the means and standard deviations of the fitted log Gaussian distributions.


2015 ◽  
Vol 24 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Elena Mirela Ionescu ◽  
Tudor Nicolaie ◽  
Serban Ion Gologan ◽  
Ana Mocanu ◽  
Cristina Ditescu ◽  
...  

Background & Aims: Even though Romania has one of the highest incidence and mortality in colorectal cancer (CRC) in Europe, there is currently no organized screening program. We aimed to assess the results of our opportunistic CRC screening using colonoscopy.Methods: A single center retrospective study to include all opportunistic screening colonoscopies performed in two 18 month periods (2007-2008 and 2012-2013) was designed. All asymptomatic individuals without a personal or family history of adenoma or CRC and with complete colonoscopy performed in these two time periods were included.Results: We included 1,807 individuals, 882 in the first period, 925 in the second period. There were 389 individuals aged below 50, 1,351 between 50 and 75 and 67 older than 75 years. There were 956 women (52.9%), with a mean age of 58.5 (median 59, range 23-97). The detection rates were 12.6% for adenomas (6.1% for advanced adenoma) and 3.4% for adenocarcinoma. Adenoma incidence (4.9% in subjects under 50, 14.7% in those aged 50 to 75, and 16.4% in those older than 75, p<0.0001) and size (6.3mm in subjects younger than 50, 9.2mm in those 50 to 75 and 10.8mm in those older than 75, p=0.015) significantly increased with age. Adenoma incidence increased in the second period (14.8% vs. 10.3%, p=0.005), while adenoma size decreased in the second period (8.4mm vs. 10mm, p=0.006). There were no procedure related complications.Conclusions: The neoplasia detection rate was 16% (12.6% adenoma, 3.4% adenocarcinoma). Adenoma incidence and size increased with age in both cohorts. In the second screening period significantly more and smaller adenomas were detected.


2014 ◽  
Vol 40 (4) ◽  
pp. 394-397 ◽  
Author(s):  
Lonneke L. IJsseldijk ◽  
Andrea Gröne ◽  
Sjoukje Hiemstra ◽  
Jeroen Hoekendijk ◽  
Lineke Begeman

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