Spot the boat: understanding the overlap of vessel and marine mammal activity around Scotland’s coastline

Student Spotlight - Emily Hague

PhD Research at Heriot-Watt University

Email: elh2001@hw.ac.uk   Twitter: @emilyhague 

If I asked you to list potential activities that may impact marine mammals (whales, dolphins, porpoises and seals) around the UK, what would come to mind? Perhaps noise? Injuries from collisions? Plastics? Shipping lanes? Well, in a nutshell my PhD is hoping to consider all of those potential impacts to marine mammals, and to investigate how, and where, multiple potential activities and their associated stressors may overlap. This will allow me to identify areas where there is more, or less, potential for cumulative impacts, and then identify areas where further research and monitoring may be required.

Vessel Activity

One of the activities I’m investigating as part of this work is vessel activity. Interestingly, data on vessel activity tends not to be easily accessible, has notable gaps (e.g. recreational vessels), and is often very coarse so doesn’t allow for detailed analysis. To address this, the aims of at least one chapter of my PhD and of the ‘Scottish Vessel Project’ are to explore ways to collect data to improve this understanding in both time and space (i.e. how does vessel activity differ in type, and volume, at different sites around Scotland?). This is a collaboration between WDC Shorewatch, UHI Shetland, the Forth Marine Mammals group, FleetMon, and many others. Together we are exploring the utility of a variety of approaches to gaining data on coastal vessel traffic around Scotland. To do this, we have deployed AIS (Automatic Identification system) receivers at a number of sites, which capture information transmitted from larger vessels (over 15m long), who by law have to transmit information of their identity, speed, route and location. Vessels under 15m don’t legally have to transmit this AIS information, and so there is little data on these smaller vessels. This has been a long-standing grey area when investigating vessel presence, and means it’s difficult to get a handle on any potential impact to marine mammals. This is especially important, as different vessel types tend to also pose their own potential risks or impact types.

[video width="1920" height="1080" mp4="http://www.mammal.org.uk/wp-content/uploads/2021/12/Dolphins-off-military-boat-Tay.mp4"][/video]

Bottlenose dolphins bow riding at the front of a military vessel. © Emily Hague

To capture smaller vessel data, we are trialling a number of approaches, including analysis of time-lapse camera and harbour or coastal webcam footage (e.g. Shetland Webcam's Sumburgh Head camera), and comparing what is spotted on these cameras versus what appears in AIS data. We’ve also developed a land-based vessel watching protocol, designed in collaboration with WDC Shorewatch. This means volunteers can record the vessels they spot whilst watching for marine mammals, and can systematically record any interactions between marine mammals and vessels (e.g. bow riding, moving away, longer dives, no reaction).

Local Studies

The importance of building an understanding of vessel activity really came to the fore recently when a humpback whale was seen in the Firth of Forth, less than 10 miles from my university campus! The sightings were quickly followed by local boat operators beginning to offer trips to see the whale. Whilst these trips may operate under the WiSe Scheme guidelines and the Scottish Marine Wildlife Watching Code, it gives the Scottish Vessel Project a great opportunity to gain data on all types of vessel activity in the vicinity of the whale, from tankers to kayaks to speedboats, to build an understanding of how the Forth may be experienced by this individual whale. In other areas, studies have observed humpback whales increasing swimming speed, increasing respiration rate and path directedness when within 500m of vessels (Scheidat et al., 2004; Schuler et al., 2019; Currie et al., 2021), and have recorded changes in surfacing behaviour even with vessels 1000m away (Gulesserian et al., 2011). Humpbacks have also been observed altering communication behaviour (from vocal signals to surface generated signals such as pectoral slapping) when background noise increases (Dunlop et al., 2010), and altering foraging activity during ship passages (Blair et al., 2016). These short-term changes may lead to cumulative, long-term consequences if vessel presence is reasonably frequent (Schuler et al., 2019), and so the activities should be carefully monitored and considered. As the Forth has only recently begun to get regular visits from different humpback whales (O’Neil et al., 2019), and has a whale-watching industry in its infancy, research and understanding is only just beginning for this region. This provides the Scottish Vessel Project a really exciting opportunity to collect data that can be used to support the management and conservation of these wonderful whale-y blubbery visitors to our seas.

Get involved!

Watches all around Scotland’s coastline are essential to help us build an understanding of vessel activity and how this differs over the course of a year and at different sites, and to gain an estimate of how much overlap there may be with marine mammals. If this has sparked your interested, the project is still seeking volunteers to carry out watches from land anywhere around Scotland, or via home-based webcam watches. If you are interested, please do get in touch with me (elh2001@hw.ac.uk), I’d be really pleased to hear from you.

I look forward to providing future updates!

For more information, check out the website: https://bit.ly/ScottishVesselProject

References

Blair, H.B., Merchant, N.D., Friedlaender, A.S., Wiley, D.N. and Parks, S.E. (2016). Evidence for ship noise impacts on humpback whale foraging behaviour. Biology letters, 12(8), p.20160005. https://doi.org/10.1098/rsbl.2016.0005

Currie, J.J., McCordic, J.A., Olson, G.L., Machernis, A.F. and Stack, S.H. (2021). The impact of vessels on humpback whale behavior: the benefit of added whale watching guidelines. Frontiers in Marine Science, 8, p.72. https://doi.org/10.3389/fmars.2021.601433

Dunlop, R.A., Cato, D.H. and Noad, M.J. (2010). Your attention please: increasing ambient noise levels elicits a change in communication behaviour in humpback whales (Megaptera novaeangliae). Proceedings of the Royal Society B: Biological Sciences, 277(1693), pp.2521-2529. https://doi.org/10.1098/rspb.2009.2319

Gulesserian, M., Slip, D., Heller, G. and Harcourt, R. (2011). Modelling the behaviour state of humpback whales Megaptera novaeangliae in response to vessel presence off Sydney, Australia. Endangered Species Research, 15(3), pp.255-264.

O’Neil, K.E., Cunningham, E.G. and Moore, D.M. (2019). Sudden seasonal occurrence of humpback whales Megaptera novaeangliae in the Firth of Forth, Scotland and first confirmed movement between high-latitude feeding grounds and United Kingdom waters. Marine Biodiversity Records, 12(1), pp.1-5. https://doi.org/10.1186/s41200-019-0172-7

Scheidat, M., Castro, C., Gonzalez, J. and Williams, R. (2004). Behavioural responses of humpback whales (Megaptera novaeangliae) to whalewatching boats near Isla de la Plata, Machalilla National Park, Ecuador. Journal of Cetacean Research and Management, 6(1), pp.63-68.

Schuler, A.R., Piwetz, S., Di Clemente, J., Steckler, D., Mueter, F. and Pearson, H.C. (2019). Humpback whale movements and behavior in response to whale-watching vessels in Juneau, AK. Frontiers in Marine Science, 6, p.710. https://doi.org/10.3389/fmars.2019.00710