Calculation of a hazard ratio (HR) [ 47] provides a method for objectively evaluating the relative risk of bycatch. HR is often defined as the ratio of the probability of death to survival. When a bycatch occurs with a constant probability (instantaneous hazard rate, m), the risk of bycatch S( t) at total presence duration t is represented as: S( t) = 1−exp(− mt). This equation means that the longer porpoises are present near a net, the more vulnerable to entanglement they become. Although the duration per presence had not a significant difference, the total duration per hour was obviously different because the number of presences was largely different between BB and NB. However, it is difficult to estimate m due to the small number of present samples, though further research may enable the risk assessment of bycatch. Cox, T. M., Read, A. J., Solow, A. & Tregenza, N. Will harbour porpoises ( Phocoena phocoena) habituate to pingers?. J. Cetacean Res. Manage. 3(1), 81–86 (2001). Taguchi M, Ishikawa H, Matsuishi T. Seasonal distribution of harbour porpoise ( Phocoena phocoena) in Japanese waters inferred from stranding and bycatch records. Mammal Study. 2010;35: 133–139.

Brandt, M. J., Diederichs, A., Betke, K. & Nehls, G. Responses of harbour porpoises to pile driving at the Horns Rev II offshore wind farm in the Danish North Sea. Mar. Ecol. Prog. Ser. 421, 205–216 (2011). Continuing the British Library’s Classic Science Fiction series, we see the re-release of Wild Harbour from Scottish writer Ian Macpherson (1905 – 1944). It follows the journey of pacifist couple Terry and Hugh who, in the ever-growing threat of war coming to the UK, abandon civilisation altogether and take to living in a cave away from the rest of the world. Amidst the foraging for food and simple lifestyle, Terry and Hugh find solace. However, as the threat of war grows closer, can the couple continue with their own personal utopia? Dähne, M. et al. Effects of pile-driving on harbour porpoises ( Phocoena phocoena) at the first offshore wind farm in Germany. Environ. Res. Lett. 8, 025002 (2013). After the company was taken to court over unpaid work by Glasgow-based printing company Bell and Bain Printers, a provisional liquidator was appointed to the company and all employee contracts - including those at Freight Design - were terminated.Kastelein, R. A., Bunskoek, P., Hagedoorn, M., Au, W. W. L. & de Haan, D. Audiogram of a harbor porpoise (Phocoena phocoena) measured with narrow-band frequency-modulated signals. J. Acoust. Soc. Am. 112, 334–344 (2002). Wright AJ, Akamatsu T, Mouritsen KN, Sveegaard S, Dietz R, Teilmann J. Silent porpoise: potential sleeping behaviour identified in wild harbour porpoises. Anim Behav. 2017;133: 211–222. Verfuß UK, Miller LA, Schnitzler HU. Spatial orientation in echolocating harbour porpoises ( Phocoena phocoena). J Exp Biol. 2005;208: 3385–3394. pmid:16109898 Dawson, S. M. C. and Communication: The behavioural and social contexts of Hector’s Dolphin vocalisations. Ethology 88, 265–276 (1991).

Clarke MR. Cephalopods in the diets of odontocetes. In Bryden MM, Harrison R (eds) Research on dolphins. Clarendon Press, Oxford, p 281–321; 1986. Kindt‐Larsen L, Berg CW, Northridge S, Larsen F. Harbor porpoise ( Phocoena phocoena) reactions to pingers. Mar Mammal Sci. 2018;35: 552–573. Larsen, F. & Eigaard, O. R. Acoustic alarms reduce bycatch of harbour porpoises in Danish North Sea gillnet fisheries. Fish. Res. 153, 108–112 (2014). Dawson SM, Read A, Slooten E. Pingers, porpoises and power: uncertainties with using pingers to reduce bycatch of small cetaceans. Biol Conserv. 1998;84: 141–146. Palka DL, Rossman MC, Vanatten AS, Orphanides CD. Effect of pingers on harbour porpoise ( Phocoena phocoena) bycatch in the US Northeast gillnet fishery. J Cetacean Res Manag. 2008;10:217–226.

Discussion

I had confirmation my rights would be returned prior to the liquidation but Freight held on to them anyway. Throughout, thepublisher would tell me one thing and do another... I still don't have my rights and have no idea when I will. Nor do I expect to see a single penny of the four-figure sum owed to me. Shambolic doesn't come close." Harris, C. M. et al. Marine mammals and sonar: Dose-response studies, the risk-disturbance hypothesis and the role of exposure context. J. Appl. Ecol. 55, 396–404 (2018). Scheidat, M. et al. Harbour porpoises ( Phocoena phocoena) and wind farms: a case study in the Dutch North Sea. Environ. Res. Lett. 6(2), 025102 (2011).

Cantor A. SAS survival analysis techniques for medical research, Second Edition. SAS Institute, North Carolina; 2003. Götz, T. & Janik, V. M. Acoustic deterrent devices to prevent pinniped depredation: Efficiency, conservation concerns and possible solutions. Mar. Ecol. Prog. Ser. 492, 285–302 (2013). Andersen, S. H. & Amundin, M. Possible predator-related adaption of sound production and hearing in the harbour porpoise (Phocoena phocoena). Aquat. Mamm. 4, 56–57 (1976). Siebert, U. et al. Post-mortem findings in harbour porpoises ( Phocoena phocoena) from the German North and Baltic Seas. J. Comp. Pathol. 124, 102–114 (2001).

Introduction

Leeney RH, Dia IM, Dia M. Food, pharmacy, friend? Bycatch, direct take and consumption of dolphins in West Africa. Hum Ecol. 2015;43: 105–118. Schaffeld, T. et al. Diel and seasonal patterns in acoustic presence and foraging behaviour of free-ranging harbour porpoises. Mar. Ecol. Prog. Ser. 547, 257–272 (2016).

Elmegaard, S. L., Johnson, M., Madsen, P. T. & McDonald, B. I. Cognitive control of heart rate in diving harbor porpoises. Curr. Biol. 26, R1175–R1176 (2016). Graham, I. M. et al. Harbour porpoise responses to pile-driving diminish over time. R. Soc. Open Sci. 6, 190335 (2019).

Location

Scholander, P. F. Experimental investigations on the respiratory function in diving mammals and birds. In Hvalradets Skrifter 1–131 (Hvalradets Skrifter, 1940). This bleak perspective is apparent from Macpherson’s first novel, Shepherds’ Calendar (1931). Like Nan Shepherd’s The Quarry Wood (1928) and Lewis Grassic Gibbon’s Sunset Song (1932), both of which have eclipsed it in popularity, Shepherds’ Calendar depicts the struggle of a young person in a rural northeast community to choose between their duty to the land and their family and their own aspirations to attend university. While both Gibbon and Shepherd, however, praise the rural landscape, presenting it as a vibrant source of being, Macpherson’s northeast is consistently brutal, filled with death and decay. It opens: Culik, B., von Dorrien, C., Müller, V. & Conrad, M. Synthetic communication signals influence wild harbour porpoise ( Phocoena phocoena) behaviour. Bioacoustics 24(3), 201–221 (2015). To develop effective and long-lasting mitigation measures, an understanding of the bycatch mechanism is essential. For instance, knowledge of the behaviour of harbour porpoises around nets helps to determine the conditions contributing to the incidence of bycatch [ 12, 30]. In the case of bottlenose dolphins ( Tursiops truncatus), there are reports of depredation [ 31], as well as observations of damage to captured fish or bait, presumably caused by the dolphins [ 32]. Other researchers showed that bottlenose dolphins spend time foraging around gillnets [ 33]. However, why harbour porpoises appear around fishing nets and become entangled is not entirely clear [ 34].