Current Species Protection Does Not Serve Its Porpoise-Knowledge Gaps on the Impact of Pressures on the Critically Endangered Baltic Proper Harbour Porpoise Population, and Future Recommendations for Its Protection

Overview

Journal Ecol Evol

Date 2024 Sep 13

PMID 39267689

Authors

Sven Koschinski

Kylie Owen

Kristina Lehnert

Katarzyna Kaminska

Affiliations

Soon will be listed here.

Abstract

Successful management requires information on pressures that threaten a species and areas where conservation actions are needed. The Baltic Proper harbour porpoise population was first listed as Critically Endangered by the International Union for the Conservation of Nature in 2008. Now, 16 years later, there is no change in conservation status despite ample conservation policy calling for its protection and an urgent need for management action to protect this population. Here, we provide an overview of the current status of the population, highlight knowledge gaps on the impact of pressures, and make recommendations for management of anthropogenic activities. Based on an exceeded limit for anthropogenic mortality, the high concentrations of contaminants in the Baltic Sea, combined with reductions in prey availability and increases in underwater noise, it is inferred that this population is likely still decreasing in size and conservation action becomes more urgent. As bycatch and unprotected underwater explosions result in direct mortality, they must be reduced to zero. Inputs of contaminants, waste, and existing and emerging noise sources should be minimised and regulated. Additionally, ecosystem-based sustainable management of fisheries is paramount in order to ensure prey availability, and maintain a healthy Baltic Sea. Stranding networks to routinely assess individuals for genetic population assignment and health need to be expanded, to identify rare samples from this population. Knowledge is still scarce on the population-level impact of each threat, along with the cumulative impact of multiple pressures on the population. However, the current knowledge and management instruments are sufficient to apply effective protection for the population now. While bycatch is the main pressure impacting this population, urgent conservation action is needed across all anthropogenic activities. Extinction of the Baltic Proper harbour porpoise population is a choice: decision-makers have the fate of this genetically and biologically distinct marine mammal population in their hands.

References

Villadsgaard A, Wahlberg M, Tougaard J . Echolocation signals of wild harbour porpoises, Phocoena phocoena. J Exp Biol. 2006; 210(Pt 1):56-64. DOI: 10.1242/jeb.02618. View

Schaffeld T, Schnitzler J, Ruser A, Woelfing B, Baltzer J, Siebert U . Effects of multiple exposures to pile driving noise on harbor porpoise hearing during simulated flights-An evaluation tool. J Acoust Soc Am. 2020; 147(2):685. DOI: 10.1121/10.0000595. View

Weijs L, Dirtu A, Das K, Gheorghe A, Reijnders P, Neels H . Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 1. Accumulation patterns in harbour seals and harbour porpoises. Environ Pollut. 2008; 157(2):437-44. DOI: 10.1016/j.envpol.2008.09.024. View

Sorensen P, Wisniewska D, Jensen F, Johnson M, Teilmann J, Madsen P . Click communication in wild harbour porpoises (Phocoena phocoena). Sci Rep. 2018; 8(1):9702. PMC: 6018799. DOI: 10.1038/s41598-018-28022-8. View

Dietz R, Fort J, Sonne C, Albert C, Bustnes J, Christensen T . A risk assessment of the effects of mercury on Baltic Sea, Greater North Sea and North Atlantic wildlife, fish and bivalves. Environ Int. 2020; 146:106178. DOI: 10.1016/j.envint.2020.106178. View

Jorundsdottir H, Norstrom K, Olsson M, Pham-Tuan H, Huhnerfuss H, Bignert A . Temporal trend of bis(4-chlorophenyl) sulfone, methylsulfonyl-DDE and -PCBs in Baltic guillemot (Uria aalge) egg 1971-2001--a comparison to 4,4'-DDE and PCB trends. Environ Pollut. 2005; 141(2):226-37. DOI: 10.1016/j.envpol.2005.08.054. View

Rojano-Donate L, Teilmann J, Wisniewska D, Jensen F, Siebert U, McDonald B . Low hunting costs in an expensive marine mammal predator. Sci Adv. 2024; 10(20):eadj7132. PMC: 11318689. DOI: 10.1126/sciadv.adj7132. View

Temple A, Langner U, Berumen M . Management and research efforts are failing dolphins, porpoises, and other toothed whales. Sci Rep. 2024; 14(1):7077. PMC: 10963780. DOI: 10.1038/s41598-024-57811-7. View

Van Bressem M, Van Waerebeek K, Aznar F, Raga J, Jepson P, Duignan P . Epidemiological pattern of tattoo skin disease: a potential general health indicator for cetaceans. Dis Aquat Organ. 2009; 85(3):225-37. DOI: 10.3354/dao02080. View

10.

Houser D, Yost W, Burkard R, Finneran J, Reichmuth C, Mulsow J . A review of the history, development and application of auditory weighting functions in humans and marine mammals. J Acoust Soc Am. 2017; 141(3):1371. DOI: 10.1121/1.4976086. View

11.

Reusch T, Dierking J, Andersson H, Bonsdorff E, Carstensen J, Casini M . The Baltic Sea as a time machine for the future coastal ocean. Sci Adv. 2018; 4(5):eaar8195. PMC: 5942908. DOI: 10.1126/sciadv.aar8195. View

12.

Hall A, Hugunin K, Deaville R, Law R, Allchin C, Jepson P . The risk of infection from polychlorinated biphenyl exposure in the harbor porpoise (Phocoena phocoena): a case-control approach. Environ Health Perspect. 2006; 114(5):704-11. PMC: 1459923. DOI: 10.1289/ehp.8222. View

13.

Miller A, Nyberg E, Danielsson S, Faxneld S, Haglund P, Bignert A . Comparing temporal trends of organochlorines in guillemot eggs and Baltic herring: advantages and disadvantage for selecting sentinel species for environmental monitoring. Mar Environ Res. 2014; 100:38-47. DOI: 10.1016/j.marenvres.2014.02.007. View

14.

Celemin E, Autenrieth M, Roos A, Pawliczka I, Quintela M, Lindstrom U . Evolutionary history and seascape genomics of Harbour porpoises (Phocoena phocoena) across environmental gradients in the North Atlantic and adjacent waters. Mol Ecol Resour. 2023; . DOI: 10.1111/1755-0998.13860. View

15.

Venn-Watson S, Colegrove K, Litz J, Kinsel M, Terio K, Saliki J . Adrenal Gland and Lung Lesions in Gulf of Mexico Common Bottlenose Dolphins (Tursiops truncatus) Found Dead following the Deepwater Horizon Oil Spill. PLoS One. 2015; 10(5):e0126538. PMC: 4439104. DOI: 10.1371/journal.pone.0126538. View

16.

Dyndo M, Wisniewska D, Rojano-Donate L, Madsen P . Harbour porpoises react to low levels of high frequency vessel noise. Sci Rep. 2015; 5:11083. PMC: 4476045. DOI: 10.1038/srep11083. View

17.

Sigray P, Andersson M, Pajala J, Laanearu J, Klauson A, Tegowski J . BIAS: A Regional Management of Underwater Sound in the Baltic Sea. Adv Exp Med Biol. 2015; 875:1015-23. DOI: 10.1007/978-1-4939-2981-8_126. View

18.

Kesselring T, Viquerat S, Brehm R, Siebert U . Coming of age: - Do female harbour porpoises (Phocoena phocoena) from the North Sea and Baltic Sea have sufficient time to reproduce in a human influenced environment?. PLoS One. 2017; 12(10):e0186951. PMC: 5650184. DOI: 10.1371/journal.pone.0186951. View

19.

Wilson L, Pine M, Radford C . Small recreational boats: a ubiquitous source of sound pollution in shallow coastal habitats. Mar Pollut Bull. 2022; 174:113295. DOI: 10.1016/j.marpolbul.2021.113295. View

20.

Wunschmann A, Siebert U, Frese K, Weiss R, Lockyer C, Heide-Jorgensen M . Evidence of infectious diseases in harbour porpoises (Phocoena phocoena) hunted in the waters of Greenland and by-caught in the German North Sea and Baltic Sea. Vet Rec. 2001; 148(23):715-20. DOI: 10.1136/vr.148.23.715. View