Annual Counts of Marine Mammals from Cape

Annual Counts of Marine Mammals from Cape Solander Botany Bay, NSW 2005 and 2006

Geoffrey A. Ross and Maryrose Gulesserian

Season Summary

2005 Season

2006 Season

Total sightings: 1964

Total sightings: 2390

Total Humpbacks: 1368

Total Humpbacks: 1607

Days counted: 67

Days counted: 66

Total registered volunteers: 34

Total registered volunteers: 28

Total volunteer hours: 2158.32

Total volunteer hours: 2118.68

Total revenue from ticket sales: $26785.39

Total revenue from ticket sales: $353581.50

Ross, Geoffrey A., and Gulesserian, Maryrose 2006

2005

2006

Humpback

1368

1607

Dolphins

557

750

Orca

0

1

Southern Right

0

4

Minke

14

5

Fur Seal

3

8

Unknown

3

14

Marlin

0

1

Pygmy Killer

15

0

False Killer

3

0

Great White Shark

1

0

Table 1: Species recorded during the 2005 and 2006 whale migration study seasons

Wayne Reynolds

Figure 1: A Humpback Whale (Megaptera novaeangliae) breaching off cape Solander


Annual Counts of Marine Mammals from Cape Solander Botany Bay, NSW 2005 and 2006 Geoffrey A. Ross and Maryrose Gulesserian Background Since the early 1990s, the whale-watching industry as a tourism activity has rapidly increased. The ecotourism industry boomed from a minor activity beginning around 1955 to a billion dollar industry by the turn of the century (Herrera and Hoagland, 2006). Whale-watching is now available in more than 500 communities around the world, offering over nine million trips annually (Herrera and Hoagland, 2006). In many parts of the world, the revenue received from whale-watching is often cited as an economic alternative to whaling (Sheidat et al 2004). Seasonal migrations of whales have captured the attention and curiosity of millions of people a year to venture out and view animals in their natural environment (Constantine et al, 2004; Hughes, 2001; Jelinski et al, 2002). Within the last 15 years, the general trend has shifted from viewing cetaceans in captivity, performing unnatural, learnt behaviour to viewing them in their natural habitats (Hughes, 2001; Jelinski et al, 2002).

The two most popular target species for whale watchers are the Humpback Whale (Megaptera novaeangliae) and the Southern Right Whale (Eubalaena australis). Both are known for their tendency to stick closer to shore during their northerly migration, and easy to pick due to their slow swimming speeds and short downtimes. However, humpbacks tend to be more predictable in their behaviour and migratory patterns, thus making them our focal study animal.

The International Whaling Commission was established in 1986 to manage the diminishing whale stocks and allow for population recovery. Since that time, whale populations have slowly been recovering from the intensive whaling they were subjected to off the east coast of Australia. Consequently, within the last two decades, much public attention has reverted to the conservation of cetaceans.

Cape Solander at Botany Bay National Park, Sydney has proved to be one of the best locations to view whales on their East Australian, northerly migration, particularly the most acrobatic species of all, humpback whales. Humpback whales are observed migrating between their feeding grounds in Antarctica and their breeding grounds in the warmer waters of the Great Barrier Reef between June and July. In the southern hemisphere, the humpback whale stocks have been categorized into six groups based on feeding aggregations. The pods observed migrating between their summer and winter habitats, past the east coast of Australia are known as Group V whales (SCUWRC, 2005; Corkeron P.J., 1995).

The Cape Solander Whale Migration Study has been undertaken from the 24th of May to the 31st of July each year since 1995, registered volunteers coordinated by NSW National Parks & Wildlife Service officers have undertaken annual counts of Group V humpback whales migrating past Cape Solander.


The aim of this study is to provide a non-invasive, long-term monitoring of the Group V population of southern humpback whales by conducting a standardised census whilst on their northerly migration. The objectives of the Cape Solander Whale Migration study are to;   

   

Monitor the movement and abundance of cetaceans off the NSW coast at Cape Solander to provide annual indices of abundance. Involve the community in the collection of scientific data in a program that has a robust experimental design and is well recognised by the scientific community. To utilise community volunteers to collect data on endangered species and to help educate visitors to the park. Such strategies would normally be beyond the financial resources of the NPWS to undertake. By the use of an icon species, educate the community on the need for conservation and management of native species. To demonstrate that the NPWS is actively involved in the management and conservation of marine species. Record whale behaviour especially around watercraft. To promote less intrusive shore-based whale watching, and encourage visitors to coastal National Parks.


Study Site Cape Solander is situated on the Kurnell peninsular within Botany Bay National Park. The viewing site is approximately 32 metres above sea level, giving observers an ideal platform to count migrating cetaceans. In addition, the Whale Viewing Platform provides volunteers and members of the public with shelter, along with information relevant to whale watching and conservation education. During the whale watching season, a caravan is also stationed on site to provide volunteers with shelter during harsh weather conditions, and to provide facilities for taking breaks. A shuttle bus is also provided on weekends for members of the public (free of charge) traveling between the Discovery Centre and the Whale Deck. This is especially convenient for people who park their cars at the Discovery Centre due to the limited spaces available at Cape Solander.

Survey Methods Between the 24th of May and the 31st of July (2005 and 2006), trained volunteers recorded the species, pod size, time sighted, bearing, distance from shore and behaviour of all marine mammals observed passing Cape Solander, Kurnell during daylight hours. Weather data was also recorded on an hourly basis, which included temperature, humidity, atmospheric pressure, wind speed and wind direction readings, as well as Beaufort estimates, cloud cover, sea and swell states. The watch was only abandoned when conditions such as heavy rain, fog or darkness substantially hindered visibility.

Public Education The whale watching season attracts thousands of people from around Sydney to Cape Solander to observe migrating whales. Educating these people on the importance of conserving cetaceans is a key factor the Cape Solander project aims to provide to the community. The permanent interpretive board erected on site during the 2003 season provides visitors information about whale biology, behaviour and conservation, along with information about the 2002 season. In addition, Discovery rangers are stationed on site during weekends to answer any questions, and hand out further information sheets to the public.

Media Attention Local and national media coverage plays a major part in advertising the site and educating the public on whale-watching. Local and Sydney-wide newspapers, TV, and radio interviews also allow for regular updates on the daily counts.

Park Visitation Throughout the years, the whale watching season has attracted more and more people a year to visit the park during the normally quiet winter months. Park ticket sales and shop sales indicate an increase in visitation to the park during peak whalewatching periods during the 2006 whale migration study period (Figure 2).


Total Revenue 2006 8000 7000 6000 5000 4000 3000 2000 1000 0 17/05 - 24/05 - 31/05 - 07/06 - 14/06 - 21/06 - 28/06 - 05/07 - 12/07 - 18/07 - 25/07 23/05 30/05 06/06 13/06 20/06 27/06 04/07 11/07 17/07 24/07 31/07 Date Figure 2: Total revenue from ticket sales, day passes and shop sales during the 2006 whale migration study period

Shop sales could not be retrieved for the 2005 season therefore could not be analyzed. However, a comparison in ticket sales between the 2005 and 2006 seasons indicates a large increase in visitations during the 2006 season. This may be attributed to the increase in media attention in 2006, attracting more people into the park. 2005 24 May to 31 May

2006 992.69

2403.20

June

12727.80

16175.70

July

13064.90

17002.60

Total

26785.39

35581.50

Table 2: Total ticket sales during the 2005 and 2006 whale migration study seasons

Volunteers During the 2005 season, 34 registered volunteers logged a total of 2158.32 hours, whilst during the 2006 season, 28 registered volunteers logged a total of 2118.68 hours. The time and effort put in by all the volunteers is critical to the collection of accurate and consistent data. Volunteers came from a cross-section of the community, which included; students, unemployed, elderly pensioners and employed people with time to spare. The data collected by the volunteers provides NPWS with an index number of cetaceans that migrate past the coast, the approximate preferred distance offshore, and average pod size. It also provides information on the peak periods of migration and the percentage annual increase/decrease in the recovering population numbers. Ross, Geoffrey A., and Gulesserian, Maryrose 2006

RESULTS 2005 Season Observations were made on 67 of the 69 days. Out of a total of 1964 animals, 1368 were Humpback whales. Other species recorded included dolphins (common and bottlenose), Minke whales, Fur Seals, Pygmy Killer whales, False Killer whales and a Great White Shark. Table 1 lists all the animals observed. 2006 Season Of the 69 days, observations were made on 66 days during the 2006 whale watch season. A total of 2390 animals were counted, of which 1607 were Humpback whales (Table 1). Other animals observed included dolphins (common and bottlenose), an Orca, Southern Right Whales, Minke whales, Fur Seals, and a Marlin. Record numbers of Humpback whales were recorded during the 2006 season. A 1.2% increase from the previous year could be attributed to a number of reasons. The 2005 season also saw a record number of Humpback whales sighted on any one day (68 animals on the 5th of July). The highest number of Humpbacks sighted on any one day during the 2006 season was on the 9th of July, with 61 animals. Figure 3 is a comparison of sightings per day between the two seasons. Humpback Counts 2005 - 2006 80 2006 2005

70

60

50

40

30

20

10

24 -M 26 ay -M 28 ay -M 30 ay -M a 1- y Ju 3- n Ju 5- n Ju 7- n Ju 9- n J 11 un -J 13 u n -J 15 u n -J 17 u n -J 19 u n -J 21 u n -J 23 u n -J 25 u n -J 27 u n -J 29 u n -J un 1Ju 3- l Ju 5- l Ju 7- l Ju 9- l J 11 ul -J 13 u l -J 15 u l -J 17 u l -J 19 u l -J 21 u l -J 23 u l -J 25 u l -J 27 u l -J 29 u l -J 31 u l -J ul

0

Date

Figure 3: Comparison of total Humpback counts per day between the 2005 and 2006 whale migration study seasons

The trend in the data set between the two seasons appears similar. However, the second peak in numbers appeared later in 2006 than in 2005, this shift is still within the observed annual variation. Ross, Geoffrey A., and Gulesserian, Maryrose 2006

A one-way ANOVA was carried out using Minitab 13, to analyze numbers of humpbacks between the two seasons. A non-significant p-value of 0.232 (at the 5% level of significance) indicates that there is no significant difference between the numbers of humpbacks recorded during 2005 and 2006. Further, a two-way ANOVA was constructed to analyze whether any difference lay between humpback numbers recorded per day between the 2005 and 2006 seasons. A p-value of 0.107 (at the 5% level of significance) denotes that there is also no significant difference in humpback numbers per day, signifying similar peaks and drops between seasons (Figure 3). Pod Sizes For both the 2005 and 2006 seasons, the mean pod size comprised of 2 individuals. Pods ranged between a single individual, to groups consisting of seven whales. Pod statistics for the two seasons are presented in Tables 3 and 4. 2005

Minimum

Maximum

Mean

Pod Size

1

6

2

Pod Distance Offshore (metres)

20

5000

2020

Pods Per Day

0

33

11

Table 3: Pod statistics for the 2005 whale migration study season

2006

Minimum

Maximum

Mean

Pod Size

1

7

2

Pod Distance Offshore (metres)

100

10000

2081

Pods Per Day

0

33

13

Table 4: Pod statistics for the 2006 whale migration study season

Pod statistics between the two seasons appear consistent. The main difference, however, lies between the maximum and minimum distances offshore. Figure 4 displays the recorded distances offshore of pods for the 2005 and 2006 seasons. A clear similarity lies between the two seasons. The majority of pods were sighted between 1000 and 2000 metres, with the least sighted between 4001 and 4500 metres.


Distance Offshore (Pods) 250 2006 2005 200

150

100

50

0 0-500

501-1000 1001-1500 1501-2000 2001-2500 2501-3000 3001-3500 3501-4000 4001-4500 4501-5000

5000+

Metres

Figure 4: Comparison between pod distances offshore between the 2005 and 2006 whale migration study seasons

Because the recorded distances are estimates, observations may be subjective. A level of ‘comfort’ appears in the 500 to 2500 meter zone. For more accurate distance measurements, volunteers must be trained at estimating distances and calibrated to one another before the season begins. Alternatively, a theodolite can be used to accurately measure distances.

During the 2006 season, volunteers recorded an animal at a distance of 10000 metres offshore. We felt that this observation was at too great a distance to include in the data set, therefore analyses were redone, omitting this observation. Table 5 displays the results obtained.

Minimum

Maximum

Mean

With all observations

100

10,000

2081

Excluding 10,000m

100

7500

2066

Excluding all observations >5000m

100

5000

1956

Table 5: Pod distance offshore during the 2006 whale migration study period Ross, Geoffrey A., and Gulesserian, Maryrose 2006

Minimum

Maximum

Mean

With all observations

20

5000

2020

Excluding all observations >5000m

20

5000

2020

Table 6: Pod distance offshore during the 2005 whale migration study period

Weather 2005 Season Due to complications with the weather station, temperature, humidity, barometric pressure and wind speed could not be recorded. However, between the 25th of May and the 17th of July, wind direction, cloud cover, Beaufort Estimate, swell length and sea state were recorded per hourly period.

The Beaufort Estimate is a scale extending from zero to 12, used to estimate wind speeds and the effects on the sea. It is estimated visually from characteristics produced by the force of the wind on the sea (Hasse and Smith, 1996). During the 2005 season, recorded Beaufort Estimates ranged from 1 to 7, with 3 being the most recorded (34% of hourly weather checks). A Beaufort Estimate of 2 (32% of hourly weather checks) and 4 (16% of hourly weather checks) followed.

Cloud cover was recorded using a universally accepted method of measuring in octas, or eighths (Bureau of Meteorology, Australia). A scale of zero to eight is used; zero being an indicator of no clouds, whilst eight representing a 100 percent cloud cover. Zero cloud cover accounted for 33 percent of all recordings in 2005, followed by 8 (17% of hourly weather checks) and 1 (12 % of hourly weather checks).

Of the three possible swell lengths, ‘mid’ was never recorded for the 2005 season. ‘Long’ accounted for the majority of recordings, with 65 percent of hourly weather checks, followed by ‘short’ at 35 percent.

Sea state is described by a modified Beaufort scale, ranging from calm to rough. Fifty percent of the 2005 recordings were ‘slight’. ‘Calm’ and ‘moderate’ followed, both at 20 percent, with ‘rough’ as the least recorded sea state (10% of hourly weather checks). Ross, Geoffrey A., and Gulesserian, Maryrose 2006

Finally, the South-west was the most recorded wind direction (33%) followed by south (16%) and north-west and north-east (both at 12% of hourly weather checks).

2006 Season A new wireless ‘Vantage Pro’ weather station was provided that digitally transmitted weather data that was recorded on site. Data was collected from 30th June to 31st July, and is presented in Table 7.

2006

Min.

Max.

Mean

Temperature (ºC)

5.1

25.0

14.262

Humidity (%)

24.0

99.0

70.981

Barometric Pressure (hPa)

1008.8

1034.2

1021.112

Wind Speed (kph)

0

31

8.520

Table 7: Summary weather data for the 2006 whale migration study season

The Beaufort Estimate ranged from 0 to 5, with the greatest number recorded at 2 (47% of hourly weather checks), followed by 1 (23% of hourly weather checks) and 4 (12% of hourly weather checks). Cloud cover ranged from 0 to 8. The most recorded cloud cover was 8, with 30 percent of recordings, followed by 7 (18% of hourly weather checks) and 6 (12% of hourly weather checks). Swell length ranged between short, mid and long, with the 76 percent of recorded lengths ‘long’ (distance between swells is greater the 100metres). Of the four possible categories of sea state (calm, slight, moderate and rough), ‘slight’ was recorded the most (54% of recordings). Finally, the three most commonly recorded wind directions were from the west (24% of hourly weather checks), north-west (15% of hourly weather checks) and south (11% of hourly weather checks). Weather data between the two seasons may be difficult to compare, as different collection methods were used. However, we are able to conclude that the conditions were similar between seasons, with the percentage of cloud cover the only difference. Data shows that the 2006 season produced more overcast days than the 2005 season.


Discussion The general timing and expected peaks of the 2005 and 2006 northern migration were as predicted. The ‘bell-curve’ reported by Paterson et al (1994) was again apparent in both seasons (Figure 3), and although the expected second peak was present two weeks later that recorded during the 2006 season it was still within the annual variation for the Solander count. Comparative data collected at Cape Solander from previous whale watch seasons indicate an average increase of 1.5 percent in humpback whale numbers per year. Data from the 2005 and 2006 seasons are consistent with this trend, with the 2006 season producing record numbers of animals. However, many factors must be taken into consideration before drawing conclusions regarding population recovery. A possible hypothesis for the rising trend may be attributed to a shift in population numbers, where individuals from other feeding groups join the Australian east coast Area V group. Other factors that may influence the rising numbers may include the possibility that pods may be migrating closer to shore, making them easier to count, or simply, population numbers may be recovering from the depleted stocks post-whaling. All these reasons must be taken into consideration before drawing conclusions about the increase in numbers. Further exploration of these factors in addition to counts from other locations and aerial survey of southern ocean stocks, would allow for a more scientifically correct conclusion.

Further Research Concerns relating to the subjectivity of weather observation require further investigation to ensure a consistent approach to recording of data by volunteers. Cloud cover, sea state, swell length and Beaufort Estimate may be influenced to some level by observer subjectivity. Further research should also focus on cetacean preference for traveling under varying oceanic conditions whilst migrating; i.e. whether cetaceans migrate further away or closer to shore, do they avoid certain currents, tides or swells etc. Accurate data on oceanic conditions may be obtained from the wave rider buoy found approximately 3 kilometers offshore from Cape Solander. Simple analyses using statistical software could identify whether whales prefer certain oceanic conditions. Establishment of the true width of the migration pathway would provide a better understanding of the population size and movement of cetaceans past cape Solander. Undertaking aerial survey of the humpback “stream” would be provide the necessary data for the comparison with Solander observational data.

Conclusion Whale watching from Cape Solander continues to be a major community attraction. The dedication of volunteers has allowed for the collection of data on all marine mammals passing Cape Solander for the last nine years. In addition, the attraction of whales has led to the increase of members of the public into the park during the normally quiet winter months. An increase in revenue, along with the education of people about the biology, history and importance of the conservation of marine mammals is successfully achieved through the Cape Solander whale migration study. Ross, Geoffrey A., and Gulesserian, Maryrose 2006

With the growing awareness and interest in marine mammals, Cape Solander continues to be a successful non-invasive whale watch site. As land-based whale watching continues to grow in popularity, so does the community appreciation and positive environmental awareness.

Acknowledgements The authors wish to acknowledge the skills and experience of the Cape Solander Whale Migration Study Volunteers without whose help this study could not continue. We would also like to thanks Mr. Wayne Reynolds whose dedication and passion for marine fauna provided the spark for this project’s ignition. We also thank the NSW Department of Environment and Climate Change for funding the project.


References Constantine R., Brunton D.H. and Dennis T. (2004). Dolphin watching tour boats change bottlenose dolphin (Tursiops truncates) behaviour. Biological Conservation, 27; 299307. Corkeron P.J. (1995) Humpback whales (Megaptera novaeangliae) in Hervey Bay, Queensland: behaviours and responses to whale-watching vessels. Canadian Journal of Zoology, 73; 1290-1299. Hasse L. and Smith S.D. (1996). Local sea surface wind, wind stress and sensible and latent heat fluxes. Journal of Climate, 10 (11); 2711-2724. Herrera G.E. and Hoagland P. (2006). Commercial whaling tourism and boycotts: An economic perspective. Marine Policy, 30; 261-269. Hughes P. (2001). Animals, values and tourism – structural shifts in UK dolphin tourism provision. Tourism Management, 22; 321-329. Jelinski D.E., Krueger C.C. and Duffus D.A. (2002). Geostatistical interactions between killer whales (Orcinus orca) and recreational whale-watching boats. Applied Geography, 22; 393-411. Paterson, R., Paterson, P., and Cato, D.H. (1994). The status of Humpback Whales (Megaptera novaeangliae) in east Australia 30 years after whaling. Biological Conservation 70; 135 – 142. SCUWRC (Southern Cross University Whale Research Centre) website – Cape Byron Project (2005). Available at: https://www.scu.edu.au/research/whales/aboutCBRP.html Sheidat M., Castro C., Gonzalez J. and Williams R. (2004). Behavioural responses of humpback whales (Megaptera novaeangliae) to whale watching boats near Isla de la Plata, Machalilla National Park, Ecuador. J. Cetacean Research Management. 6 (1); 63-68.
