Scientist and ferry operator: Working together the advantages of collaboration

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1 Scientist and ferry operator: Working together the advantages of collaboration Andrew D Williams 1,2, Cathryn Owens 3, Tom Brereton 1, Lisa Browning 4, Ed Harland 3, Rolf Williams 1 1 Biscay Dolphin Research Programme, 6 Manor Way, Lee on Solent, Hampshire, England PO13 9JH 2 University of Southampton, School of Biological Sciences, Division of Biodiversity and Ecology, Bassett Crescent East, Southampton SO16 7PX UK 3 Durlston Marine Project, Durlston Country Park, Swanage, Dorset, UK 4 Hampshire Wildlife Trust, Woodside House, Woodside Road, Eastleigh, Hampshire SO50 4ET UK SUMMARY Ferries provide an arterial form of transport providing the life-blood between isolated island communities as well as a bridge connecting all of the major land-masses around the world. There are currently 76 identified species of whale and dolphin (known as cetaceans), of which only 12 are well studied. However, very little is known about the remaining species. These animals are afforded legal protection in many countries through legislation such as the Marine Mammal Protection Act in the USA, Australia and New Zealand and the European Union habitats directive. This paper outlines two areas where scientists and ferry operators have successfully adopted a multidisciplinary approach to addressing these issues. Study one describes a dedicated cetacean survey conducted between Portsmouth and Bilbao, illustrating some examples of significant findings. Study two will consider the impact of anthropogenic noise on a group of bottlenose dolphins off the Dorset coast of England. INTRODUCTION Ferries provide an arterial form of transport providing the life-blood between isolated island communities as well as a bridge connecting all of the major land-masses around the world. With the concept of Marine Motorways this important form of transport around the world is likely to increase over the coming years. At the same time, globally, we are developing an increasing awareness of the vital role that the oceans play. Ecologically, it is recognised that the best bio-indicators of the health of our oceans are the top predators, such as marine mammals. The critical debate hinges on the conflicting demands of protecting this environment versus allowing human activities that are considered nationally or internationally important. There are currently 76 identified species of whale and dolphin (known as cetaceans), of which only 12 are well studied. However, very little is known about the remaining species. These animals are afforded legal protection in many countries through legislation such as the Marine Mammal Protection Act in the USA, Australia and New Zealand and the European Union habitats directive. This requires greater understanding of these animals and a pro-active approach to the minimisation of disturbance, displacement and physical harm.

2 Species IUCN status (derived from Threats in NE Atlantic waters IUCN red data book Klinowska1991) Harbour porpoise Insufficiently known By-catch Common dolphin Insufficiently known By-catch Striped dolphin Insufficiently known By-catch Bottlenose dolphin Insufficiently known By-catch Risso s dolphin Insufficiently known Unknown Atlantic white sided dolphin Insufficiently known By-catch White beaked dolphin Insufficiently known By-catch Long finned pilot whale Insufficiently known Traditional directed hunt False killer whale Insufficiently known Unknown Pygmy killer whale Insufficiently known Unknown Killer whale Insufficiently known Unknown Cuvier s beaked whale Insufficiently known Unknown Northern bottlenose whale Insufficiently known Unknown Sowerby s beaked whale Insufficiently known Unknown Sperm whale Insufficiently known Unknown Minke whale Insufficiently known Directed hunt Sei whale Vulnerable Unknown Fin whale Vulnerable Directed hunt Blue whale Endangered Unknown Humpback whale Vulnerbale Unknown Table 1: IUCN conservation status of species recorded during the BDRP surveys of the Bay of Biscay and English Channel Several authors have considered the potential environmental impacts of shipping on marine mammals. Of particular concern are anthropogenic (man-made) noise, collisions, and the wave/wake pattern effects produced by fast ferries. This paper outlines two areas where scientists and ferry operators have successfully adopted a multidisciplinary approach to addressing these issues. Study one describes a dedicated cetacean survey conducted between Portsmouth and Bilbao, illustrating some examples of significant findings. Study two will consider the impact of anthropogenic noise on a group of bottlenose dolphins off the Dorset coast of England. STUDY 1: FIXED ROUTE PLATFORMS OF OPPORTUNITY AS AN ENVIRONMENTAL TOOL The Biscay Dolphin Research Programme (BDRP) is a voluntary marine research and conservation organisation which undertakes monthly, year-round surveys across the Bay of Biscay from the 37,000 tonne P & O ferry, the Pride of Bilbao. The ferry follows a (more or less) fixed route between England and Spain, and samples a representative range of topographical features and underwater habitats found in the Bay of Biscay (figure 1). These include: the continental shelf west and south-west of Brittany, France (46-49 N by 4-6 W, depth <200m); the shelf edge (46-48 N by 3-5 W, depth m); the abyssal plain (44-46 N by W, mean depth 4000m) and the Cantabria coast, northern Spain (43 N by 3 W, depth <200 m). On each trip, effort-based cetacean surveillance work is carried out by a team of three experienced observers, using standard survey methods developed for platforms of opportunity by the Cetacean Group of the Mammal Society. Watches are maintained continuously from dawn until dusk. Recording is made from the bridge of the ship, at a height of 32m and at a ship speed of knots. Observers, scan ahead, covering 135 o of arc from just ahead of the beam. When cetaceans are encountered the following variables are recorded: time; position of the ship (using the ship s global positioning system);

3 distance and bearing of animals to the ship; species type(s); number of animals in the group; age and behaviour of individuals; orientation of the animals relative to the ship; ships speed and direction of travel; and environmental conditions such as sea state, swell height, wind speed and direction, and visibility At fifteen to thirty minute intervals, repeat recordings of the ship's position, speed and environmental recordings are made and entered onto a standard proforma. Effort data enables the number of sightings to be scaled to recording effort, and the calculation of relative abundance. The surveys have made an important contribution to our understanding of the distribution and abundance of cetaceans in the Bay of Biscay and English Channel, and at a broader level have provided new ecological information on poorly known species such as the Cuvier s beaked whale. Between August 1995 and December monthly trips were made, with over 92,000 km of recording effort being made in light to moderate seas (sea state four or less) and good visibility (more than 2km). Year-round BDRP sightings and effort data enable models to be constructed of species distributions, occupancy, movements, and to interpret these in terms of species life cycles and habitat usage and calving periods. In particular, this approach aids our understanding of cetacean use of differing habitats that cannot be gained by dedicated surveys undertaken during the summer only. As an example, Figure 1 shows the striking seasonal distribution and abundance patterns of Common Dolphin (Delphinus delphis) in the Bay of Biscay. Figure1 a-d show the northward and apparent inshore movement of this species as winter approaches. Combined BDRP data from the Bay of Biscay/English Channel, and data from Celtic Sea surveys (Reference 1) indicates that the Celtic Sea/Channel wintering population moves offshore and west to breed and calve on the Celtic-Biscay shelf-edge in the spring (May and June). Subsequently, wider population dispersal occurs including into the deep waters of the Bay of Biscay abyssal plain (Reference 2 &3). This movement had not been apparent in previous studies and is a significant finding. The importance of an understanding of Common Dolphin seasonal movements can be seen when viewed against major events in the area. Mass mortality of common dolphins through by catch has been recorded from the Brittany and Cornish coasts during 1992, 1997 and 2000 (Reference 4). In Winter the oil tanker Erica sank and released oil into the sea. In all these cases it can be seen that these events occur in the wintering area of this population of dolphins. (Fig 2 a&b). The continuity of the surveys is also important for monitoring long term-effects. Any effects on the fertility of cetaceans due to the toxins released during the Erica event will not be manifest for between 6 and 8 years (Reference 5) as calves born during the year 2000 become sexually mature. The BDRP ferry surveys also allow us to identify areas for further fine scale investigations and have given us an insight into a previously enigmatic species Cuvier s beaked whale (Ziphius cavirostris). This species was reported in the literature as shy of ships, rarely seen and were thought to travel around the world s oceans (Reference 6). Fig 3 shows the distribution of beaked whale species in the southern Bay of Biscay. From this a study of Cuvier s beaked whales was started by BDRP using mark-recapture (REF) photo-id techniques and a newly developed technique for mapping the permanent scars (Plate X) to allow for individual identification. BDRP data shows that it is likely that these individuals also remain or return to the same area over years. This species has suffered a number of mass mortalities in recent years and recent events in the Bahamas have highlighted the part that military sonar may have played in at least some of those events. The work of BDRP in showing the presence of the species in very specific habitats has alerted other scientists to the possibility that habitat and site fidelity may be two factors compounding the effect of the sonar and causing the strandings. Both of these pieces of work are of global significance and have enhanced the understanding and awareness of the scientific community.

4 STUDY 2: FAST FERRIES AND MARINE MAMMALS In response to the competition and accelerating pace of the ferry market, fast ferries have developed as a high-speed efficient solution for carrying people and their vehicles to their destination. With such convenience, the fast ferry industry has rapidly become a growth sector in the global transport market. However, in the light of such proliferation, there is concern that such development outstrips our understanding of the environmental impacts. Concerns focus on the issues of anthropogenic (man-made) noise, collisions, wave patterns, and the adverse effects these factors are thought to pose to marine wildlife and their habitats (Reference 7). Although each of these issues is worthy of considerable attention, the remit of this study was noise. To date, most research has focussed on the air-bourne noise that fast ferries produce - a distinctive, low frequency 'hum'. In Denmark thousands of complaints lead to the introduction of tight noise exposure limits specifically related to fast ferries operating in residential areas (Reference 8). In water, far less is known. However, as fast ferry services now operate in many areas of known cetacean abundance, underwater noise is an area of considerable importance. The significant potential impacts include the masking of cetacean sounds (both broad band echolocation and foraging clicks, and tonal communication and social cohesion sounds), and physical changes in the auditory capabilities of the animals, such as temporary threshold shift (TTS), permanent threshold shift (PTS) and noise induced hearing loss (NIHL). In the first study of its kind, Durlston Marine Project in collaboration with CONDOR Ferries, sought to investigate the potential acoustic disturbance of cetaceans by fast ferry services. The subjects of the study were at that time the UK s fastest passenger ferry - CONDOR EXPRESS - and a group of free-ranging bottlenose dolphins (Tursiops truncatus) off the Dorset coast. As a short-term study, the research sought to consider whether (a) the CONDOR EXPRESS fast ferry had the potential to cause acoustic disturbance to bottlenose dolphins and (b) whether there was any short-term evidence of disturbance/displacement of the local dolphins. CONDOR EXPRESS is the UK s fastest ferry. The ferry is a wave-piercing catamaran made by INCAT of Tasmania. In March 1997, CONDOR EXPRESS was transferred to a new, twice daily service from Poole to the Channel Islands. Her specifications are as follows (Reference 9) : (Length overall 86.27m; Beam overall m; Draught m when planning; Deepest draught m; No. passengers 775; Vehicle capacity 175 cars; Top speed 41 knots; Propulsion system 4 water jets powered by diesel engine, cycling 24 tonnes water per second at top speed. The acoustic signature of the ferry was measured using 2 separate monitoring systems: 1) the boat hydrophone : a ball hydrophone and preamplifier suspended 2m below a small fishing boat. The boat was drifting in 18m of water outside Swanage Bay, approximately 1 km west of the track of the ferry (closest point of approach 900 m); 2) the tripod hydrophone : a fixed ball hydrophone (on a tripod) suspended 1.2m above the seabed in 11m of water in Durlston Bay. This hydrophone lies approximately 3.5 km west of the ferry s track. Both signals were recorded on DAT and replayed into an Advantest R9211C analyser to obtain spectra. The CONDOR EXPRESS ferry traverses the Durlston Marine Research Area 4 times in 24 hours. The Durlston Marine Research Area (Figure 4) is the site of a long-running study of bottlenose dolphins. Since 1988, when a systematic cetacean watch was initiated, the study has grown to encompass cetacean behaviour, acoustics and photo-identification (References 10,11 and 12). Five animals have been identified as the only regular visitors to the Marine Research Area, (Reference 13) and these are the subject of ongoing studies (Reference 14). Due to the nature of the experimental conditions, it was not possible to undertake focal animal behavioural studies. Therefore, our assessment of dolphin disturbance relied upon the simplest possible parameter: the frequency of sightings in the study area. Two questions were considered: Has there been a change in the frequency of dolphin sightings since the ferry started operating? Has there been a change in the time of day at which sightings occur within the study site, which may be related to the timing of the ferry crossings?

5 Dolphin sightings data from quantified effort surveys conducted by trained, experienced observers were used in combination with sightings from casual observers, to provide enough data to compare levels of dolphin activity before and since the commencement of the fast ferry service. Typical spectra are shown in Figures 5 and 6. For the 1 khz spectrum the measurement bandwidth is 1.2 Hz and for the 20 khz spectrum it is 25 Hz. Each spectrum is averaged from 16 input spectra. The dominant sound sources within the 100 Hz to 20 khz frequency range are the two strong lines around 500 Hz, thought to be caused by machinery. In addition to these discrete lines, machinery also produces a continuous spectrum across the range 100 Hz to above 5 khz, though the contribution above 1 khz is relatively small. Above 10 khz the sound energy increases again, due to displaced water impacting the sea surface. Measurements from both hydrophones indicate that the 500 Hz contribution is directional, and is strongest when the ship is approaching the hydrophone. This effect has also been noted in air (Reference 8). It is likely that in deeper water, the impeller blade rate of Hz would also be important. Figure 7 shows the year by year analysis of all dolphin sightings within the Durlston Marine Research Area, allowing comparison of the first year following the commencement of the ferry service with the 6 previous years. In 1997/8, dolphin sightings were reported on 70 days. Although this is considerably lower than the previous year, the figure is within 0.11 standard deviations of the mean for the 6 previous years (mean = 73.3, sd = 31.1). Figure 8 shows an analysis of the proportion of all sightings days on which sightings occurred between 1400 hrs and 1700 hrs, this being a period when the ferry passes through the study area twice. In 1997/8, sightings occurred between 1400 hrs and 1700 hrs on 36% of all sightings days, an identical figure to the mean for the 6 previous years. The audiogram for the bottlenose dolphin shown in Figure 9 (adapted from Reference 15) indicates that the dominant 500 Hz feature of the fast ferry's acoustic signature falls within a relatively insensitive part of the hearing range. However, it is possible that masking of the broad band sounds may occur, with potential impacts on foraging success. The ferry's higher frequency element falls in a region of much greater auditory sensitivity. It is conceivable that the increase in wideband, high frequency noise caused by the ferry might reduce the range over which the dolphins' vocalisations are effective, especially in the khz range typical of social communication. Potentially therefore, fast ferries may be a cause of disturbance for bottlenose dolphins. However, at the ranges where the measurements of received level (RL) from this vessel were taken there appears to be little risk of physical damage to the study animals. Of course, acoustic disturbance might not be the only acoustic impact fast ferries have on cetaceans: other aspects such as the startle factor of such fast craft, or the production of temporary bubble barriers (which reflect dolphin sonar) might also be important. In terms of the local dolphin population, the sightings analyses show no significant signs of disturbance. However, when interpreting the data, consideration needs to be given to following: the Durlston dolphins seem to be unusual in the rarity of their observed use of tonal communication. encounters with the ferry were (are?) likely to be infrequent and brief, as the animals have a large range, and the ferry spends a short time in the study area. therefore the 500 Hz contribution is less likely to be significant. We acknowledge that this is a short-term study, reliant upon relatively crude data. However, it highlights a need for more in depth studies and, given the rapid expansion of the fast ferry industry, we urge industry designers and scientists to work together to look into this as a matter of urgency. DISCUSSION Thanks to the pioneering cooperation between P & O and BDRP there is now a developing understanding of the very important role that ferries and other platforms of opportunity can play in monitoring the health of our oceans. Despite these and other important breakthroughs, many people remain as yet unaware that routine ferry services can create the opportunity for extraordinary scientific discoveries.

6 We hope that the case studies provided in this paper illustrate how the developing relationship between the ferry industry and science has the potential to be mutually beneficial, and lights the way for how individual ferry companies can contribute to this. However, at the same time, we hope to have highlighted how these positive benefits can quickly turn to negative impacts if cooperative working relationships are not applied to service development and planning. Despite the appealing convenience, fast ferries are increasingly attracting a negative image (Reference 7). Although initial work on anthropogenic noise suggests the potential for impact is inconclusive, by using the template of cooperation between industry and science, it would be possible to look at design, routing and other operating issues to mitigate any negative factors. For example, a change as simple as a minor deviation of route may serve to dispel concerns over a seal haul out, cetacean feeding grounds or other significant areas. A reduction in speed through an area known for slow moving whales may significantly minimise the potential for catastrophic collision. Even in build and design major contributions can be made to the introduction of anthropogenic noise into the marine environment thus reducing the more subtle effects of masking important sounds that marine mammals utilise. Whatever your perspective, it can no longer be ignored that the future lies in multidisciplinary work, closer cooperation, and in the development and implementation of an integrated approach. Monitoring trends and changes is only useful if it s done in the long term. Ferries are in the unique position to facilitate this. The breakthroughs already achieved in our understanding of oceanic cetaceans and seabirds only serves to highlight the need for these symbiotic alliances to be nurtured.

7 FIGURES AND PLATES SEASONAL DISTRIBUTION OF COMMON DOLPHIN IN THE Bay of Biscay Number of. animals seen all ages, months and sea states 49.0N 49.0N 48.5N 48.5N 48.0N 48.0N 47.5N 47.0N 46.5N 46.0N 45.5N 45.0N 44.5N 44.0N 43.5N 43.0N No. animals W 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W 47.5N 47.0N 46.5N 46.0N 45.5N 45.0N 44.5N 44.0N 43.5N 43.0N No. animals W 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W a) January to March b) April to June 49.0N 49.0N 48.5N 48.5N 48.0N 48.0N 47.5N 47.0N 46.5N 46.0N 45.5N 45.0N 44.5N 44.0N 43.5N 43.0N No. animals W 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W 47.5N 47.0N 46.5N 46.0N 45.5N 45.0N 44.5N 44.0N 43.5N 43.0N No. animals W 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W c) July to September d) October to December Figure 1: Seasonal movements of common dolphins in the Bay of Biscay from data covering the period

8 51.0N 50.5N Key: No. animals 50.0N 49.5N N 48.5N N W 5.0W 4.0W 3.0W 2.0W 1.0W a) Autumn (September to November) 51.0N 50.5N 50.0N 49.5N 49.0N 48.5N 48.0N Key: No. animals b) Winter (December to February) 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W Figure 2 : Seasonal abundance maps of Common Dolphin in the English Channel recorded from surveys on the P&O ferry, the Pride of Bilbao. 50.5N 50.0N 49.5N 49.0N 48.5N 48.0N 47.5N 47.0N 46.5N 46.0N 45.5N 45.0N 44.5N 44.0N 43.5N 8.0W 7.0W 6.0W 5.0W 4.0W 3.0W 2.0W 1.0W Figure 3: Distribution of beaked whales in southern Bay of Biscay

9 Figure 4: The Durlston Marine Research Area

10 Fig. 5: Boat hydrophone output up to 1 khz, closest point of approach (900 m). Fig. 6 : Tripod hydrophone output up to 25 khz, closest point of approach (3.5 km).

11 Fig. 7: Dolphin sightings days per year, 1991/2 to 1997/8. Fig. 8: Proportion of dolphin sightings occurring between 1400 and 1700, 1991/2-1997/8.

12 Fig 9: Bottlenose dolphin audiogram (adapted from Richardson et al 1995)

13 REFERENCES 1 Tregenza, N.J.C., Berrow, S.D., Hammond, P.S., and Leaper, R (1997) Common Dolphin, Delphinus delphis L., Bycatch in bottom set gillnets in the Celtic Sea. Rep. Int. Whal. Commn Brereton T.M., Williams A.D.and Williams R, (2000) Distribution and relative abundance of the common dolphin (Delphinus delphis) in the Bay of Biscay. In research on Cetaceans 13 Evans P.G.H., Cruz J. and Raga J.A. (eds). 3 Brereton T.M., Williams A.D. and Williams R, (1999) Distribution, relative abundance and population structure of the common dolphin (Delphinus delphis) in the Bay of Biscay. A presentation to the 13th Biennial Conference of the Society for Marine Mammalogy, Maui, Hawaii USA Kirkwood J.K., Bennet P.M., Jepson P.D., Kuiken T., Simpson V.R. and Baker J.R. (1997) Entaglement in Fishing gear and other causes of death in cetaceans stranded on the coasts of England and Wales. The Veterinary Record 141, Evans W.E (1994) Common Dolphin, White-bellied porpoise Delphinus delphis Linnaeus, In Handbook of Marine Mammals, Volume 5: The first book of dolphins. Ridgeway S.H. and Harrison R(Eds.) Academic Press Heyning J. E. (1989) Cuvier s beaked whale: Ziphius cavirostris, G Cuvier In Handbook of Marine Mammals Harrison and Richardson (Eds). Academic press Eardley J. and Lankester R. (2000).High Speed Ships: What is the real cost of this innovation? Coast NET Bulletin. vol 5.2 p5 6 Autumn Odegaard J, Neilson O.W. and Gosling A. (1997) External noise from fast ferries. In Proceedings Fourth International Conference on Fast Sea Transportation, Sydney, Australia, July , Baird Publications Ltd Pp Moore P.M. (1998) 35 Years of Fast Ferries in the Channel Islands - a taster from the forthcoming book Condor Ferries internet website October Browning L.J. (1997) Durlston Marine Research Area: A status report on the physical environment, wildlife and human use. P Harland E., Turnbull M., Williams R., and Copley V. (1996a) The Durlston cetacean monitoring project. In European Research on cetaceans 9. Evans P.G.H. and Nice H. (eds): Harland E., Plowman R. and Turnbull M. (1996b) Deployment of a sea-bed mounted hydrophone for cetacean monitoring. In European Research on cetaceans 9. Evans P.G.H. and Nice H. (eds): Williams A.D. (in prep) Behavioural Ecology of a group of free ranging bottlenose dolphins off the Dorset coats of southern England. 14 Browning L.J. (1999) Durlston Marine Research Area - a Research Action Plan Durlston Marine Project Richardson W.J., Greene C.R., Malme C.I. and Thompson D.H. (1995) Marine Mammals and NoiseAcademic Press. 1995

14 Author profile Andy Williams is a cetacean ecologist working for the Biscay Dolphin Research programme. He has been working in the field of marine mammals since A graduate of Canterbury Christ Church College at the University of Kent UK he began to concentrate on the behavioural ecology of cetaceans in Andy is the founder of Biscay Dolphin Research Programme and has many years experience in ocean abundance and distribution monitoring. During 2000 Andy joined Southampton University and is working towards his PhD on the ecology and life history of Cuvier s beaked whales. He is also very active in research areas such as mitigation of anthropogenic impacts on cetaceans, marginal population biology and bio-acoustics. He is a researcher and advisor to the Durlston Marine Project.