+44 (0)1368 865 722

C-POD Porpoise Click Detector

All European Union (EU) countries surrounding the Baltic Sea are involved in the international project Static Acoustic Monitoring of the Baltic Sea Harbour Porpoise.

All European Union (EU) countries surrounding the Baltic Sea are involved in the international project Static Acoustic Monitoring of the Baltic Sea Harbour Porpoise (SAMBAH, www.sambah.org). The aim of SAMBAH is to secure the conservation of the Baltic Sea harbour porpoise (Phocoena phocoena). The harbour porpoise subpopulation in the Baltic Sea is classed as critically endangered (CR) on the International Union for Conservation of Nature (IUCN) Red List (Hammond et al. 2008). See www.porpoisedetectors.co.uk for some background information on harbour porpoises.


Data on harbour porpoise activity is collected by SAMBAH using static acoustic dataloggers, called C-PODs, deployed throughout the Baltic Sea. See www.c-podclickdetector.co.uk for details on how C-PODs work. For SAMBAH C-POD positions, see www.sambah.org; ca. 300 C-PODs were deployed between May 2011 and May 2013.

As outlined in www.cetaceanmonitoring.com, multiple methods are often employed to study marine mammals thoroughly. The SAMBAH project also plans to tag harbour porpoises, conduct acoustic/visual trials and calibration tests, and write a corresponding literature review.


The SAMBAH project will perform density analysis and habitat modelling. In order to determine average density and abundance of harbour porpoises across the whole Baltic Sea, density analysis methodology involves taking animal counts from specific areas and looking at the spatial relationship between those areas (http://help.arcgis.com). The SAMBAH project uses two types of point transect methods (e.g. Whitehead 2009) for density analysis: cue counting (e.g. Marques et al. 2011), which uses the detection of individual clicks and snapshot methods, which use detection of individuals or groups within a certain time frame. See Buckland et al. (2005) for an introduction into these methods.

Habitat modelling techniques investigate how harbour porpoise presence relates to their environment (e.g. depth, Sea Surface Temperature (SST), salinity, food sources etc.). The SAMBAH project uses Generalised Additive Models (GAMs, https://en.wikipedia.org) and Generalised

Additive Mixed Models (GAMMs, e.g. Wood (2006); Block et al. (2011)) to produce distribution maps. These methods not only highlight distribution and potential habitat preferences, but can also show possible ‘hotspots’. Harbour porpoise distribution results are then combined with anthropogenic data (e.g. fishing, tourism etc.) to see if there is any overlap, and therefore potential for increased risk.


The SAMBAH project is still in data collection and analysis phase. Preliminary results have been presented at conferences (e.g. Amundin et al. 2010) and at a progress meeting in conjunction with the 2013 European Cetacean Society (ECS) conference in Setubal, Portugal. Reports are due to be published in 2014.


For regular updates on SAMBAH progress, check out their activities page at www.sambah.org, and their Facebook page at www.facebook.com

To learn more about harbour porpoise research in the UK and the Bay of Fundy see www.porpoisedetector.co.uk and www.porpoisedetectors.com respectively.


Amundin M., Carlén I., Carlström J., Teilmann J., Thomas L. & Tougaard J. (2010) SAMBAH. Static acoustic monitoring
of the baltic Harbour Porpoise. In: 38th Symposium of the European Association of Aquatic Mammals, p. 22, Lisbon Zoo, Portugal
Block B.A., Jonsen I.D., Jorgensen S.J., Winship A.J., Shaffer S.A., Bograd S.J., Hazen E.L., Foley D.G., Breed G.A.,
Harrison A.L., Ganong J.E., Swithenbank A., Castleton M., Dewar H., Mate B.R., Shillinger G.L., Schaefer K.M., Benson S.R., Weise M.J., Henry R.W. & Costa D.P. (2011) Tracking apex marine predator movements in a dynamic ocean. Nature 475, 86-90.
Buckland S.T., Anderson D.R., Burnham K.P., Laake J.L., Borchers D.L. & Thomas L. (2005) Introduction to distance
sampling: Estimating abundance of biological populations. Oxford University Press, Oxford.
Hammond P.S., Bearzi G., Bjørge A., Forney K., Karczmarski L., Kasuya T., Perrin W.F., Scott M.D., Wang J.Y., Wells R.S.
& Wilson B. (2008) Phocoena phocoena (Baltic Sea subpopulation). In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. URL www.iucnredlist.org.
Marques T.A., Munger L., Thomas L., Wiggins S. & Hilderbrand J.A. (2011) Estimating North Pacific right whale Eubalaena
japonica density using passive acoustic cue counting. Endangered Species Research 13, 163-72.
Whitehead H. (2009) Estimating abundance from one-dimensional passive acoustic surveys. Journal of Wildlife
Management 73, 1000-9.
Wood S.N. (2006) Generalized additive models: an introduction with R. Chapman & Hall/CRC, Boca Raton, Florida, USA.