Royal Netherlands Institute for Sea Research
Royal Netherlands
Institute for Sea Research

Harbour porpoises

The harbour porpoise, Phocoena phocoena a small dolphin species that became locally virtually extinct in the 1960s and 1970s, made a dramatic comeback in Dutch waters in the late 20th century. This comeback was documented by seawatchers (monitoring seabird passage from coastal headlands)1 and by beachcombers2. Neither the disappearance of this species in the Southern Bight, nor its re-appearance in recent decades is well understood. 

The harbour porpoise <i> Phocoena phocoena</i>. Photo: Wilbert & Corina Romijn

Protected species

The Harbour Porpoise is a strictly protected species, but the (inter-)national legislation meant to ensure an adequate conservation of marine mammals is complex and sometimes conflicting3. A Harbour Conservation Plan, co-authored by NIOZ, was published in 20114 and its recommendations are currently under review.

Long-term trend in Harbour Porpoise strandings in The Netherlands (1930-2018). Note that not all strandings were reported prior to the late 1950s, when the animal was still abundant in Dutch waters.

Current studies

Studies nowadays conducted by NIOZ focus on apex predators and their ecological interrelationships within the North Sea and in Dutch coastal waters. The harbour porpoise is not a focal species within these studies, but is considered as an integrated component of the North Sea marine ecosystem, with a function as a facilitator in multi-species feeding frenzies targeting pelagic prey (small fish mostly). Population trends are monitored on the basis of strandings data and seawatching reports (www.trektellen.nl).

Publications

1Publications on the come-back of Harbour Porpoises in Dutch waters
Camphuysen, C.J. 1994. The Harbour Porpoise Phocoena phocoena in the southern North Sea, II: a come-back in Dutch coastal waters? Lutra 37: 54-61. PDF 
Camphuysen, C.J. & Leopold, M.F. 1993. The Harbour Porpoise Phocoena phocoena in the southern North Sea, particularly the Dutch sector. Lutra 36: 1-24. PDF 
Camphuysen, C.J. 2004. The return of the harbour porpoise (Phocoena phocoena) in Dutch coastal waters. Lutra 47: 113-122. PDF
Camphuysen, C.J. & Peet, G. 2006. Whales and dolphins of the North Sea. Fontaine Uitgevers, Kortenhoef. PDF
Camphuysen, C.J. & Smeenk, C. 2016. Bruinvis. In Broekhuizen: Spoelstra, S.K., Thissen, J.B.M., Canters, K.J. & Buys, J.C. (eds) 2016. Atlas van de Nederlandse Zoogdieren. Natuur van Nederland 12, Naturalis Biodiversity Center, Eis Kenniscentrum insecten en andere ongewervelden, Zoogdiervereniging en KNNV Uitgeverij, Zeist. Chapter Noordkaper-Bruinvis 
Meij van der, S.E.T. & Camphuysen, C.J. 2006. Distribution and diversity of whales and dolphins (Cetacea) in the Southern North Sea: 1970-2005. Lutra 49(1): 3-28. PDF 
Haelters,  J. & Camphuysen, C.J. 2009. The harbour porpoise (Phocoena phocoena L.) in the southern North Sea: Abundance, threats, research- and management proposals. Royal Belgian Institute of Natural Sciences (RBINS), department Management Unit of the North Sea Mathematical Models (MUMM) & Royal Netherlands Institute for Sea Research (NIOZ) Project financed by IFAW (International Fund for Animal Welfare) - IFAW Internationaler Tierschutz-Fonds GmbH, IFAW, Brussels. PDF 

2 Publications documenting the increase in strandings of porpoises in Dutch waters
Camphuysen, C.J., Smeenk, C., Addink, M.J.,Grouw van, H. & Jansen, O.E. 2008. Cetaceans stranded in the Netherlands from 1998 to 2007. Lutra 51(2): 87-122. PDF 
Camphuysen, C.J. & Smeenk, C. 2016. Bruinvis. In Broekhuizen: Spoelstra, S.K., Thissen, J.B.M., Canters, K.J. & Buys, J.C. (eds) 2016. Atlas van de Nederlandse Zoogdieren. Natuur van Nederland 12, Naturalis Biodiversity Center, Eis Kenniscentrum insecten en andere ongewervelden, Zoogdiervereniging en KNNV Uitgeverij, Zeist. Chapter Noordkaper-Bruinvis 
Peltie, H., Baagoe, H.J. , Camphuysen, C.J., Czeck, R.,  Dabin, W., Daniel, P., Deaville, R., Haelters, J., Jauniaux, T., Jensen, L.F., Jepson, P.D., Keijl, G.O., Siebert, U., Canneyt van, O. & Ridoux, V. 2013. The stranding anomaly as population indicator: the case of Harbour Porpoise Phocoena phocoena in North-western Europe. PlosONE 8(4) e62180: 1-14. PDF 

3 Publications regarding the complexity of legislation
Camphuysen C.J. & A. Trouwborst 2009. De Bruinvis in de Noordzee: ongrijpbaar visvarken verstrikt in visnetten en regelgeving. De Lev. Nat. 110: 253-256. PDF 

4 The Harbour Porpoise conservation plan
Camphuysen, C.J. & Siemensma, M.L. 2011. Conservation plan for the Harbour Porpoise Phocoena phocoena in The Netherlands: towards a favourable conservation status. NIOZ Report 2011-07 PDF