The behaviour of bottlenose dolphins (Tursiops truncatus) in relation to boat

traffic in New Quay, Cardigan Bay.

Megan Rush 10458821

BSc (Hons) Marine Biology and Coastal

Ecology, Plymouth University.

Stage 4

Project Advisor: Dr Clare Embling

Journal: Marine mammal science journal

Abstract:

The impact to marine mammals from human activity is most evident on the coastline within the

UK. Bottlenose dolphins (Tursiops truncatus) are a highly social species and, as they are

protected, the impact of this activity needs to be monitored. Particularly within the summer

months when tourism peaks, New Quay, Cardigan Bay within Wales is well known for high

levels of boat traffic. Due to the area’s rich feeding and nursery grounds, this is a well-known

site for the semi-resident bottlenose dolphins. Effort data was collected from the harbour wall

located in New Quay on a daily basis from 9am to 5pm between 2012-15. This data was

observed in regular intervals of fifteen minutes over a two-hour period. Within these intervals,

environmental conditions were recorded alongside sighting of marine mammal activity. This

included the presence of boats within a 300-metre radius of bottlenose dolphins and their

displayed behaviours, which is the focus of this study. In this study, there was only one

significant behavioural response towards the presence of boats. The behaviour displayed was

observed as being travelling in conjunction with long dives and surfacing irregularly ((D.f= 1,

p

1

Introduction:

In the marine environment, a constant challenge is understanding how human activities can

impact upon marine mammals. A common threat to the marine environment, particularly

marine mammals and megafauna, is from vessel activities and the disturbance they cause

(Nowacek et al., 2001). To establish behavioural changes in marine mammals within the

ecosystem, their behaviour when confronted with a range of vessel activities is the focus of a

growing body of knowledge (Gill et al., 2001). This is linked with the increase in human anthropogenic activities that can cause constraints on the ecosystems megafaunas inhabit. A

change of behaviour to cetacean species can be the result of anthropogenic activities, such as

fisheries, sonar and tourism (Richardson and Würsig, 1997). In recent years, there has been a

worldwide increase in the number of dolphin watching trips on a range of vessels. This is

increasing the risk of disturbance to their natural behaviours, which is particularly evident in

summer months due to the rise in tourism (Constantine et al., 2004).

In response to these issues, there has been a concerted effort by the scientific community to

investigate whether boat activity effects marine animal behaviour (Constantine et al., 2004;

Pierpoint et al., 2009; Lusseau et al., 2006; Gregory and Rowan, 2001). In particular, studies on

dolphin behaviour have reported that boats can alter the behavioural responses. Behaviours,

such as feeding, resting and socialising, are more commonly observed as being avoided when

there is an interaction with boats (Nowacek et al., 2001; Williams et al., 2002; Lusseau et al.,

2006). In relation to vessel activities, Bedjer et al. (2006) and Lusseau et al. (2006) evidence

indicated that bottlenose dolphins exhibited a range of varied behavioural responses, increasing

swimming speed, diving periods and the direct avoidance of boats.

Therefore, many scientific studies have investigated how dolphin populations respond to boat

activity (Wilson et al., 1997; Forest, 2001; Williams et al., 2002; Constantine et al., 2004; Papale

et al., 2011). Evidence suggests that the most common and traumatic impact on dolphins

involves direct contact with boats, which can result in injury or mortality (Wells et al., 2008).

Although, the actual mortality rate is lower than might be expected as dolphins often show

behaviours of avoidance towards boats, which may also explain why these dolphins inhabit

areas of high boat use (Gregory and Rowan, 2001; Lusseau, 2005; Neumann and Orams, 2006;

Pierpoint et al., 2009). It is easier to make observations about dolphins through physical

evidence, such as their mortality and injury rates, than it is to observe their behaviour changes

(Mattson et al., 2005). Hence, there is little understanding of whether boat activity can alter

dolphin behaviour and what these changes may mean.

The existing studies on dolphin behaviour predominantly focuses on the short term responses.

Consequently, permanent behavioural changes are currently difficult to assess (Nowacek et al.,

2001; Pierpoint et al., 2009). Lusseau (2005) argues that the long term change in the behaviour

of dolphins could lead to alteration in their population sizes and avoidance of their preferred

habitat, which could potentially cause them to decline in numbers. In the short term, he also

argues that dolphins could return to the disturbed habitat, but with increasing numbers of boat

activity, this could drive them out of their home range (Wilson et al., 1997). Furthermore, the

increasing number of boats could alter the population’s habitat preferences. This could alter the

foraging capabilities of dolphins, causing an increase in stress levels that could impact upon

their population numbers (Lusseau, 2005; Lusseau et al., 2006).

Bottlenose dolphins (Tursiops truncatus) are a widely distributed and studied species that are

found in tropical to temperate regions throughout the world’s oceans (Constantine et al., 2004;

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Lusseau, 2005; Papale et al., 2011). This means that within the UK efforts must be made to

understand anything that may negatively impact on the population, which is particularly

important in Cardigan Bay where a semi-resident population resides. The research collated will

be supported by previous evidence to why Cardigan Bay is under a SAC. However, for this

location there is no current evidence for the long-term impacts from boat activity on the

bottlenose dolphins’ behavioural response. This potential disturbance by boat presence could

potentially cause the permanent change in bottlenose dolphins’ behaviour and their site

preference to certain locations (Christiansen et al., 2010; Lusseau, 2005). Therefore, this area is

protected by a SAC because of its importance for the species. This research study will

investigate whether there has been an impact over a period of three years (2012-15) and if

boats are impacting their behaviour. A code of conduct is already in place, but further

conservation methods could be put in place. The code of conduct is implemented in Cardigan

Bay to protect cetaceans and to minimise disturbance from boat activities.

Cardigan Bay is a study site that is located on the western coast of Wales where there is a semi-

resident population of bottlenose dolphins (Wood, 1998). Within the UK, both coastal

bottlenose dolphin groups are semi-resident. From the use of photo identification to identify

individuals, it has been proven that some two to three hundred individuals are semi-resident

within Cardigan Bay. This species is known to occupy a certain site that is otherwise known as

their home range (Wilson et al., 1997; Hudson, 2014). A home range is defined as an area where

an animal moves for normal activities, such as foraging, mating and caring for young (Burt

1943; Gubbins, 2002). The dolphins seen within Cardigan Bay are observed yearly from April to

October and particularly in the summer months (Gregory and Rowan, 2001). Often in the winter

months, however, they have been observed in or around North Wales and the Irish Sea

(Pierpoint et al., 2009). New Quay is under the Special Area of Conservation (SAC) under the

European Union Habitat Directive. This is because these dolphins tend to occupy this location as

it has favourable conditions for feeding and young rearing (Simmonds et al., 2013; Hudson,

2014).

Especially in the summer months, vessel activity is a common occurrence seen in Cardigan Bay,

which coincides with the interactions of bottlenose dolphins (Gregory and Rowden, 2001;

Pierpoint et al., 2009). There has been investigations between organisations (Sea Watch and

Cardigan Bay Marine Wildlife centre) within New Quay to whether boat interactions have a

negative behavioural response on the semi-resident dolphins. High numbers of wildlife tour

boats, fishing trips, commercial fishing, recreational activities, privately owned motorboats as

well as sailing are often seen throughout the bay, especially in the summer months. This causes

a distinct threat towards the dolphin population from disturbance of anthropogenic activities

that can lead to the behavioural changes or changes in their site preference (Lusseau et al.,

2006; Richardson, 2012). The first long-term studies began in 1994 where a dolphin monitoring

programme was established (Pierpoint et al., 2009). Throughout the monitoring process,

several actions have taken place into the protection of these dolphins from boat interactions.

The Ceredigion District Council created a code of conduct (Appendix 1, Figure 1) for all vessel

activities to follow, and the location became a SAC in 2004 under the European Habitats

Directive (CCC, 2008). In relation to recreational boat activity in Cardigan Bay, no significant

impact to bottlenose dolphin behaviour was found despite an investigation by Gregory and

Rowden (2001).

In contrast, Feingold and Evans (2014) argue that there is a negative behavioural response

towards the increasing number of boats in the bay because their data illustrated that dolphins

avoided boats. Disturbance poses a large threat towards this semi-resident population as the

impacts on their behaviour can lead to avoidance (Constantine et al., 2004). Overall, the current

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evidence is inconclusive to whether boats affect dolphin behaviour. This could be due to some

populations of dolphins being more sensitive towards boat activity compared to others.

Avoidance towards boats in conjunction with feeding, resting and socialising has been reported

in several studies (Nowacek et al., 2001; Williams et al., 2002; Lusseau et al., 2006). Over a

period of time, however, there are other studies that have observed a neutral behavioural

response from dolphins that are cohabiting alongside boats (Constantine et al., 2004; Sini et al.,

2005).

Aim and Objectives: The SAC regulations were the result of previous studies at Cardigan Bay; therefore, this study

may help understand the effectiveness of these provisions. The aim of this study is to determine

whether there is an impact from boat activity upon the behaviour of bottlenose dolphins in New

Quay, Cardigan Bay. The first objective is to collate secondary data through the months of April

to October 2012-2015. The second objective is to format all data so that it can be statistically

analysed. The third objective is to determine whether there is a relationship between dolphin

behaviour and their interactions with boats. The hypothesis for this study is that bottlenose

dolphins will show a behaviour of avoidance towards boat activity in New Quay, Cardigan Bay.

Methods: Study Area: There is a local population of bottlenose dolphins that inhabit the coastal waters of Cardigan Bay which is located on the western coast of Wales. This population have been recorded within this bay during summer months, which classifies them as being a semi-resident population. During other periods of the year, they have been reported in other locations, such as North Wales, Bangor (Gregory and Rowan, 2001; Feingold and Evans 2014). Cardigan Bay is a shallow bay with a depth of

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Environmental data was collected throughout the surveys onto data sheets at set times from the surveyors who were specifically trained for data collection. A coding sheet was used to help classify the variation in environmental conditions. These environmental conditions are recorded every 15 minutes to see if there are any changes that could alter the observations. The environmental data consisted of the general weather, sea state and wind direction. General weather was observed by using a scale from 1 to 6, where 1 represented fair and 6 sun with showers. The sea state was coded from 0 to 6+ based from a Beaufort scale; however, data used in this report is measured from sea state 3 and below. This is because the ability to observe species above sea state 3 would create restrictions. Another factor was the wind direction that

Figure 2a). Scientific area conservation map of Cardigan Bay. Figure 2b) New Quay Bay

land based survey location.

B)

A)

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was recorded using a compass, this was done as certain prevailing winds would determine the sea state. Any visibility below 2km was not used as it is hard to sight species in the bay during any presence of misty and foggy conditions.

Throughout the survey marine animal activities (seals, porpoises and bottlenose dolphins) were recorded every 15 minutes as either groups or as individuals whether they were seen or not would be noted. The behaviour type was also noted, however, in this study only bottlenose dolphin behaviour was used. The behaviours were categorised into specific behaviours for example, staying, feeding, travelling, playing or avoidance behaviours (Appendix 2, Figure 3). An example of showing a behavioural response of avoidance would be predicted to be travelling away, long dives, and milling within the bay to avoid boat presence. Not only was the behaviour and number of animals recorded, but also the number of boats within the bay whether they be entering or leaving the area. Boats were categorised into different types (Table 1). They were also recorded if they had an encounter with a dolphin and the distance from the dolphin (50m or 300m). They recorded the number of boats seen within a 300 metre radius of the dolphin(s) and the activity of the boat to monitor if they are following the Ceredigion code of conduct (Ceredigion District Council, 2010 (Appendix 1, Figure 1)).

Table1: Boat type code in New Quay

MB Motor Boat SB Speedboat or RIB SS Speed boat with Water-Skier SAIL Sailing boat or Windsurfer CF Commercial Fishing Boat VPB Visitor Passenger Boat C Canoe/Kayak/Paddleboard J Jet Ski, Personal water craft R Cetacean Research Boat

Statistical Analysis: The hypothesis for this study is to establish whether bottlenose dolphins show a behavioural

change with the presence of boats within Cardigan Bay. In this study, each behaviour was

treated as a different category against the number of boats within 300 metres. This approach

was used to investigate if there are more behavioural traits towards avoidance than other traits.

Only specific codes of behaviour were used for the statistical analysis as many did not have

many replicates, I needed data with several replicates to be able to compare differences (Table

2). Many different behaviours were recorded over the duration of the surveys; however, it was

decided that only those behaviours with high frequencies would be analysed. Therefore, the

statistical analysis was run on the following behaviours: staying, slow movement (S2); staying,

long diving (S3); staying, fast movement (S6); travel with regular surfacing (T1); and travel,

irregular surfacing (T2). All statistical analyses were run using R studio (Version 0.99.489).

Next, an ANOVA analysis was run to look at the differences in dolphin behaviour and boats

within 300 metres. A Generalised Linear Model (GLM) Binomial Aero Stretcher, the functional

link was family. This was run to analyse the different behavioural presence in relation to boat

presence, but the GLM was run before the ANOVA, while the purpose of the ANOVA was to back

up the results. It was only possible to study dolphin and boat presence because of issues with

data sets. Merging presence and absence data together was difficult due to the size of the data

set. There was not enough time to be able to manually move and alter the data set as it could not

be done via a code on the computer software (Exel and Access).

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Table 2:

Bottlenose

dolphin

behaviours code

Results: Between the months of April and October, the total number of surveys from 2012 to 2015

totalled 3,575 observation watches (Table 3). Environmental data was collected throughout the

surveys onto data sheets at set times (Appendix 3, Figure 4). A coding sheet (Appendix 2, Figure

3) was used to help classify the variation in environmental conditions during the surveys. The

total number of sightings of bottlenose dolphins throughout 2012 to 2015 was 693 (Table 4 and

Figure 5) and the number of boats encountered with these sightings totalled 7,283 (Table 5 and

Figure 6). Main behaviours observed were staying, slow movement (S2); staying, long diving

(S3); staying, fast movement (S6); travel with regular surfacing (T1); and travel, irregular

surfacing (T2). In 2013, there was an increase in the amount of boats within the bay and

decrease in the number of dolphins sighted. This was as a result of high numbers of vessel

activity. In the year of 2013 there was a Welsh youth and junior sailing championships which

was held in New Quay (RYA 2013), which would contribute to the higher than average numbers

of boat presence in the bay.

Dolphin Presence and Boat Presence:

Within the years of 2012-15 there was a significant effect in one particular behaviour that

displayed, travelling in conjunction with long dives and surfacing irregularly with the presence

of boats in 300 metres (T2, Appendix 2, and Figure 3). The significant result is observed in the

behaviour of T2 with the presence of boats (D.f= 1, p

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Table 3: Number of surveys per month between the years of 2012 -2015.

Months 2012 2013 2014 2015 Total

April 109 117 100 126 452

May 124 116 134 138 512

June 146 118 135 159 558

July 131 120 153 137 541

August 123 124 156 146 549

September 115 102 129 140 486

October 115 113 126 123 477

Total 863 810 933 969 3575

Table 4: Number of sightings per month between the years of 2012 -2015.

Months 2012 2013 2014 2015 Total

April 16 12 15 20 63

May 27 21 24 26 98

June 28 27 26 30 111

July 29 31 30 25 115

August 30 30 26 28 114

September 23 25 25 20 93

October 25 23 28 23 99

Total 178 169 174 172 693

Table 5: Number of boats per month between the years of 2012 -2015.

Months 2012 2013 2014 2015 Total

April 40 37 107 74 258

May 59 185 234 134 612

June 383 226 357 364 1330

July 400 638 401 302 1741

August 500 811 280 419 2010

September 433 203 211 63 910

October 63 142 102 115 422

Total 1878 2242 1692 1471 7283

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Discussion The data from this study suggests that there is only one behaviour that is significantly different

in the presence of boats. This behaviour displays travelling in conjunction with long dives and

irregular surfacing which currently is not linked to the behaviour of avoidance. However, this

behaviour could change to avoidance with a rise in boat activity. Despite there being no

immediate threat to the semi-resident population, an increase in tourism could have a greater

impact on behavioural changes due to the presence of boats. Therefore, it could be that there is

a tipping point of boat traffic that has not yet been met at New Quay (Gregory and Rowden,

2001). Anomalies, such as the Welsh Youth and Junior Sailing Championships held at the bay in

2013, contributed to an approximate doubling of boat traffic. The result of this was that the

number of boats within the bay doubled in this year compared to others. This could have had an

Figure 5: monthly bottlenose dolphin sightings throughout 2012-2015.

0

5

10

15

20

25

30

35

April May June July August September October

2012 2013 2014 2015

Figure 6: Number of boats per month between the years of 2012-2015. Monthly boat numbers in-between 2012-2015.

0

100

200

300

400

500

600

700

800

900

April May June July August September October

2012 2013 2014 2015

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impact on the dolphins and their behaviour. Should human activities such as this base

themselves at the bay, there is a potential intensification of traffic on a more regular basis, so

given the potential and growing popularity of the site, it is not an inconceivable future problem.

This could theoretically pose a stress to the dolphins and may cause them to re-locate.

There are several existing and ongoing studies focusing on dolphins and other cetacean species

behaviour towards boat activity but no definitive answer on the impact (Gregory and Rowan,

2001; Pierpoint et al., 2009; Feingold and Evans, 2014). Though this study presents a single

significant change in their behaviour towards boats, this could be explained by only using

presence data. A few studies stated that some behaviours, such as feeding, resting and

socialising, are frequently observed as being altered during boat interactions (Nowacek et al.,

2001; Williams et al., 2002; Lusseau et al., 2006). The scope of the behaviours of this study was

more focused on active behaviours than interpretations of those behaviours, so this potentially

limits the likelihood of biased results. Lusseau et al. (2006), Bejder et al. (2006) and Veneruso et

al. (2011) had a broader scope of observed behaviours both before and after boat interaction. If

this was observed in the study from this paper, a greater insight into potential altered

behaviour would have been obtained. Two previous studies within Cardigan Bay illustrated the

typical behaviours of bottlenose dolphins with close proximity to boats, whereas the study from

this paper was unable to identify any typical behaviours at these times. Feingold and Evans

(2014) stated that dolphins spent more time travelling and foraging than feeding, resting and

socialising, and Pierpoint et al. (2009) observed few behaviours that could be associated with

feeding in the presence of boats. However, these papers also fail to compare and contrast

behaviours with and without close proximity to boats. The issues raised both in previous

studies and in this paper could highlight the lack of a standard approach on how best to observe

the impact of boat and dolphin interactions.

Some research has observed bottlenose dolphins acclimatising to vessel activity within close

proximity in their habitat. Much like this study, dolphins with frequent interactions with boats

in their home-ranges were cohabiting and displayed no signs of a disturbed behaviour, in

Mexico (Acevdeo 1991), New Zealand (Constantine et al., 2004) and Scotland (Sini et al., 2005).

This behaviour has also been observed with hectors dolphins with no avoidance behaviour of

boats being observed up to 50 minutes after initial interaction (Bejder et al., 1999). The fact that

more than one species of dolphin in different areas at different times shows no disturbance of

dolphin behaviour should not be ignored. Perhaps in some instances certain species or groups

of dolphins can successfully cohabit with human anthropogenic activities. The bottlenose

dolphin may be one of those species especially groups that inhabit coastal areas as they are

more commonly sharing an area with boats that offshore dolphins. Certain bottlenose dolphin

groups could be more sensitive than others which could determine why some are cohabiting

with boat interactions.

Not all dolphin with boat interactions show a positive behavioural response. Boats that operate

in a negative or threatening manner can potentially cause distress to the dolphins, which would

be indicated by their behaviour (Constantine et al., 2004). When at sea, however, boats should

follow a set Ceredigion Code of Conduct (CCC, 2008) and adhering to certain rules. In my study,

by having a code of conduct that is being followed could result in low levels of a negative

behavioural response towards boats. A limitation of this study could be its focus on instances

when dolphins and boats are present together and not when one is present without the other.

The negative behaviour of dolphins in response to boats could be for those instances where

there is a breach of code of conduct. Changes in dolphin energy costs, foraging technique,

echolocation/communication, habitat use (avoidance of areas) and prospective mating and

young could threaten the species (Bejder et al., 2006; Christiansen et al., 2010; Constantine et

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al., 2004; Hastie et al., 2003; Lusseau, 2005). The data collected in this study does not currently

indicate that there is a threat to the population at Cardigan Bay. As the behaviour of

significance displayed dolphins travelling with long dives, which could represent them foraging

or feeding. Despite this study only considering presence data, other studies also show no

current large threat to the population in Cardigan Bay (Feingold and Evans, 2014; Pierpoint et

al., 2009).

Researchers of previous studies have proposed that dolphins’ response towards boats is to

vacate the area. If the exposure is repeated over a period of time, this could potentially lead to

dolphins permanently leaving an area or expanding their home-range (Lusseau, 2005; Wilson et

al., 1997). Another response to the presence of boats seen within other communities of dolphin

is cohabitation, seen in a group of bottlenose dolphins in Scotland (Sini et al., 2005). This study

showed that the dolphins in Cardigan Bay are showing similar behavioural representation of

the dolphins in Scotland, supporting the possibility that they have habituated with boat activity.

The dolphins in Cardigan Bay could be cohabiting with the boats by their behavioural response

of diving when boats are present. So by diving this could be an avoidance of the boats, but in

this case it does not currently show the response of avoidance. Cetaceans are unquestionably

more at risk of being affected by higher levels of boat activity in coastal areas (Lemon et al.,

2006). This could cause a short-term disruption to coastal dolphins, but if this exposure

happened over a prolonged period, it could affect their behavioural traits.

Conclusion: In this study there was only one behaviour of significance from dolphins towards the presence

of boats in New Quay, Cardigan Bay. The behaviour observed as travelling currently does not

suggest that dolphins are under threat within this bay. This is down to the behavioural response

linking with long diving displays which could be down to dolphins foraging. It seems that the

dolphins are either cohabiting with boats or the point of substantial impact has not been

reached. It could also be inferred that the group within Cardigan Bay are not as sensitive as other populations in that have shown avoidance behaviours towards boats. The presence of

boats and dolphins together was the central focus of this study, which excluded absence data as

it was not possible to analyse it. Understanding the full impact to the bottlenose dolphin

population, therefore, may or may not have been affected by this issue with the data analysis. If

this investigation was to be continued, there could be several ways in which it could be

improved. The ability to merge both presence and absence data for statistical analysis would be

the first suggestion from this study. Currently, the data collection form only records the first

interaction between dolphin and boat. It is the suggestion of this study to design a more robust

form to capture all interactions in the 15-minute period. In future studies, a better picture of

the impact of boat behaviour may be determined if the adherence to the Ceredigion Code of

Conduct is also observed.

Acknowledgements:

I would like to give a thank you to Sarah Perry of Cardigan Bay Marine Wildlife Centre for all of

her help throughout this project. I am also very thankful to all of the CBMWC volunteers from

2012-2015 who collected all of the data for this study as well as staff who also worked there. In

addition I am very grateful to Dr Clare Embling for all of her guidance and help throughout this

project. I would also like to thank Dr Andy Foggo for his help regarding some complications.

Finally a big thank you to my family and Nathan for their support throughout this study.

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References Acevedo, A. (1991) ‘Behavior and movements of bottlenose dolphins, Tursiops truncatus, in the

entrance to Ensendada De La Paz, Mexico’, Aquatic Mammals. 17, 137-147.

Bejder, L., Dawson, S. and Harraway, J. (1999). Responses by Hector's dolphins to boats and

swimmers in Porpoise bay, New Zealand. Marine Mammal Science, 15(3), pp.738-750.

Bejder, L., Samuels, A., Whitehead, H., Gales, N., Mann, J., Connor, R., Heithaus, M., Watson-Capps, J., Flaherty, C. and Krützen, M. (2006) ‘Decline in Relative Abundance of Bottlenose Dolphins Exposed to Long-Term Disturbance’, Conservation Biology, 20(6), pp.1791-1798. Burt, W. (1943) ‘Territoriality and Home Range Concepts as Applied to Mammals’, Journal of Mammalogy, 24(3), p.346. CCC (2008) Cardigan Bay Special Area of Conservation (SAC) management scheme. Aberaeron:

Ceredigion County Council, 179 pp.

Ceredigion District Council, 2010. Ceredigion Recreational Boat Users Code of Conduct. Available online: http://www.cardiganbaysac.org.uk/wp-content/uploads/2010/04/ceredigion-marine-code-2010.pdf [accessed on 10 August 2016]. Christiansen, F., Lusseau, D., Stensland, E. and Berggren, P. (2010) ‘Effects of tourist boats on the behaviour of Indo-Pacific bottlenose dolphins off the south coast of Zanzibar’, Endangered Species Research, 11, pp.91-99. Constantine, R., Brunton, D.H. and Dennis, T. (2004) ‘Dolphin-watching tour boats change bottlenose dolphin (Tursiops truncatus) behaviour’, Biological Conservation, 117(3), pp. 299–307. Feingold, D. and Evans, P.G.H. (2014) ‘Bottlenose dolphin and harbour porpoise monitoring in Cardigan Bay and Pen Llŷn A’r Sarnau Special Areas of Conservation 2011–2013’ Sea Watch Foundation and Natural Resources Wales report, (95). Forest, A.M. (2001) ‘The Hawai’ian Spinner Dolphin, Stenella long- irostris: Effects of Tourism’

MSc thesis. Texas AandM University, College Station, USA.

Gill, J.A., Norris, K., Sutherland, W.J. (2001) ‘Why behavioural responses may not reflect the population consequences of human disturbance’. Biological Conservation 97, 265–268. Gregory, P.R., and Rowden, A.R. (2001) 'Behaviour patterns of bottlenose dolphins (Tursiops truncatus) relative to tidal state, time-of-day, and boat traffic in Cardigan Bay, West Wales', Aquatic Mammals 27.2, pp.105-113. Gubbins, C. (2002) ‘Use of Home Ranges by Resident Bottlenose Dolphins (Tursiops truncatus) in a South Carolina Estuary’. Journal of Mammalogy, 83(1), pp.178-187. Hastie, G., Wilson, B., Tufft, L. and Thompson, P. (2003) ‘Bottlenose dolphins increase breathing synchrony in response to boat traffic’, Marine Mammal Science, 19(1), pp.74-084. Hudson, T.A., (2014) 'Bottlenose dolphin (Tursiops truncatus) responses to vessel activities in New Quay Bay' M.Sc. thesis, Bangor University. Lemon, M., Lynch, T., Cato, D. and Harcourt, R. (2006). Response of travelling bottlenose dolphins (Tursiops aduncus) to experimental approaches by a powerboat in Jervis Bay, New

12

South Wales, Australia. Biological Conservation, 127(4), pp.363-372. Lusseau, D. (2005) 'Residency pattern of bottlenose dolphins Tursiops spp. in Milford Sound, New Zealand, is related to boat traffic', Marine ecological progress series 295(6) pp. 265-272. Lusseau, D., Slooten, L. and Currey, R.J. (2006) ‘Unsustainable dolphin-watching tourism in Fiordland, New Zealand’, Tourism in Marine Environments, 3, pp. 173–178. Mattson, M.C., Thomas, J.A. and St. Aubin, D. (2005) ‘Effects of boat activity on the behavior of Bottlenose dolphins (Tursiops truncatus) in waters surrounding Hilton Head island, south Carolina’, Aquatic Mammals, 31(1), pp. 133–140. Neumann, D. R. and Orams, M. B. (2006) ‘Impacts of ecotourism on short-beaked common dolphins (Delphinus delphis) in Mercury Bay, New Zealand’, Aquatic Mammals, 32, 1–9. Nowacek, S.M., Wells, R.S. and Solow, A.R (2001) 'Short term effects of boat traffic on Bottlenose Dolphins, Tursiops truncatus, in Sarasota Bay, Florida' Marine mammal science 17(4) pp. 673-688. Papale, E., Azzolin, M. and Giacoma, C. (2011) ‘Vessel traffic affects bottlenose dolphin (Tursiops truncatus) behaviour in waters surrounding Lampedusa island, south Italy’, Journal of the Marine Biological Association of the United Kingdom, 92(08), pp. 1877–1885. Pierpoint, C., Allan, L., Arnold, H., Evans, P., Perry, S., Wilberforce, I. and Baxter, J. (2009) 'Monitoring important coastal sites for bottlenose dolphin in Cardigan Bay, UK', Journal of the Marine Biological Association of the United Kingdom, 89(5), pp. 1033–1043. Richardson, H. (2012) 'The effect of boat disturbance on the bottlenose dolphin (Tursiops truncatus) of Cardigan Bay in Wales' M.Sc. Thesis, UCL (University College London). Richardson, W.J. and Würsig, B. (1997) ‘Influences of man‐made noise and other human actions on cetacean behaviour’, Marine and Freshwater Behaviour and Physiology, 29(1-4), pp. 183–209. Rstudio, (2015) Version 0.99.489

Rya.org.uk. (2013). Medals decided at the RYA Zone and Home Country Championships. [online]

Available at:

http://www.rya.org.uk/newsevents/news/Pages/MedalsdecidedattheRYAZoneandHomeCount

ryChampionships.aspx [Accessed 13 Mar. 2017].

Simmonds M, Green M, James V, Eisfeld S, Lott R. (2013) ‘Assessing the Cardigan Bay bottlenose dolphin SACs’, ECOS 34:46-55. Sini, M. I., Canning, S. J., Stockin, K. A. & Pierce, G. J. (2005) ‘Bottlenose dolphins around Aberdeen harbour, north east Scotland: A short study of habitat utilisations and the potential effects of boat traffic’, Journal of the Marine Biological Association of the United Kingdom, 85(6), 1547-1554. Veneruso, G. and Evans, P.G.H. (2012) ‘Bottlenose Dolphin and Harbour Porpoise Monitoring in Cardigan Bay and Pen Llŷn a’r Sarnau Special Areas of Conservation’ CCW Monitoring Report No. 95. 66pp. Wells, R.S., Allen, J.B., Hofmann, S., Bassos-Hull, K., Fauquier, D.A., Barros, N.B., DeLynn, R.E., Sutton, G., Socha, V. and Scott, M.D. (2008) ‘Consequences of injuries on survival and

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reproduction of common bottlenose dolphins (Tursiops truncatus) along the west coast of Florida’, Marine Mammal Science, 24(4), pp. 774–794. Williams, R., Trites, A.W., Bain, D.E. (2002) ‘Behavioural responses of killer whales (Orcinus orca) to whale-watching boats: opportunistic observations and experimental approaches’, Journal of Zoology, London 256, 255–270. Wilson, B., Thompson, P. M. And Hammond, P. S. (1997) 'Habitat use by bottlenose dolphins: seasonal distribution and stratified movement patterns in the Moray Firth, Scotland', Journal of Applied Ecology 34, 1365–1374. Wood, C.J. (1998) ‘Movement of bottlenose dolphins around the south-west coast of Britain’, Journal of Zoology, 246(2), pp. 155–163.

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Appendix

Appendix 1:

Fig 1: Ceredigion County Council Code of Conduct

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Appendix 2:

Fig 3: Key used to determine dolphin behaviour, weather codes and sea state, using the

beautfort scale

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Appendix 3:

Fig 4, Table used to record environmental information during the two-hour

survey period.