Assessing health and fine scale movement of the humpback whale, Megaptera novaeangliae, in urbanised coastal zones
Background
About 80 000 people enjoyed whale watching on the Gold Coast in 2014. This generated an income for the city of approximately 7 mio AUD not including the indirect economic stimulation for the tourism industry. In fact, the stretch of coastline ranging from the very south end of the Gold Coast to the tip of Moreton Island experiences the worlds largest Humpback Whale (Megaptera novaeangliae) migration every year with 8 000 individuals in 2006 (DEWR, 2007) and an estimated 22 000 Humpback Whales in 2015. Humpback whale numbers have been steadly increasing by around 8-10 % every year (Noadet al., 2008). There are indications that this trend is slowing down (Franklin, 2014). The IUCN – the World Conservation Union (Hilton-Taylor, 2000) and the Queensland Nature Conservation (Wildlife) Regulation 1994 both still classify SouthernHumpback Whales as ‘‘vulnerable’’ but there is consideration that status may be changed to “least concern”. Some reports were made “celebrating” the recover of the southern humpback whale population. Considering that pre-whaling population size has not been reached yet and that the recent health of individuals has been declining further studies are needed. Humpback Whales annually migrate between their summer feeding grounds in Antarctica to their tropical breeding grounds in winter. The exact timing of the migration period can vary from year-to-year (DEWR,2007) and depends on a number of climate and water properties. In general, Humpback Whales are sighted in southern Australian waters in May and migrate slowly up the east coasts. By October the majority of whales have started their southward migration and sightings are rare after November. The Gold Coast area functions similar to a bay in which the current reverses and calm waters become present in particular in October each year (Tomlinson and Foster, 1987). This makes the Gold Coast a unique area as a resting spot in partiuclar for mothers with calves (Meynecke et al., 2012). In addition upwelling occurs along the continental shelf (Tomlinson pers. comment).
The south-east coastline of Queensland is one of the most populated areas in Australia with more than 2 million people - increasing yearly by 10-13% with resultant impacts upon the adjoining marineenvironment (ABS, 2008). It is one of themost rapidly growing regions in the world (Skinner et al., 1998). Coastal development and tourism activities have the potential to affect the behavior of Humpback Whales and impact their habitat. Because of their presence in shallower coastal waters in the South-west Marine Region, they may be susceptible to disturbance from tourism operations and impairment of near-shore waters from coastal development and vulnerable to climate change induced changes in the marine environment.At peak times up to 40 vessels following the Humpback Whales have been reported (Gold Coast Bulletin, 2008). Ocean currents such as the East Australian Current are likely to shift or even weaken with increased ocean temperatures with unforeseen consequences for migrating marine life such as Humpback Whales. Strandings are directly linked to ocean currents and climate variables (Meynecke and Meager, 2016). On a smaller scale, interactions between Humpback Whales and boats as well as constructions such as pipelines and shark nets (Gribble et al., 1998)will increase with predicted development in southern Queensland waters.
While it has been demonstratedthat significant populations of marine mammals can coexist with highly developed coastal environments (Chilvers et al., 2005), impacts of and interactions with coastal development on M. novaeangliae are poorly known and the environmental pressure on marine megafauna is increasing.Fatal incidents with the more rare southern right whale in Moreton Bay in recent years have demonstrated this. Interpreting the rapidly increasing numbers of Humpback Whales as an indicator of a healthy population is a false judgment.Humpback whales continue to recover from their 90% population decline in the late 1960s caused by decades of whaling. The population will be stable when a stable optimum is reached (s-shaped population growth) and its current increase may be an overestimation (Lynch and Fagan, 2009). Concerning are reports of an increase inmortality and deteriorated health of individualslikely a response to higher population density in combinationwith high stress levels caused by changed krill availability in Antarctica, temperature and current changes and direct incidents with humans putting in question that the population will reach a stable optimum.
Making informed decisions about the population status and adapting protection to climate change requires information on movement patterns, health status and core activities of humpback whales in relation to physical parameters such as currents and behavioural activity in combination with previously collected long term point observations along the east coast of Australia.
Objectives
The main objectives of this study are to collect data on humpback whale abundance, distribution, movement patterns together with physical water properties and to assess population health.This allowsthe continuation for prolonged and intense studies of humpback whales in the Gold Coast region. The following elements have been identified as project objectives:
provide more scientific data on the pathways and behaviours of migrating humpback whales integrating existing information with new techniques
establish long and short term movement over interannual migration
allow measurements and comparison between disturbed and undisturbed regions
investigate the value of south-east Queensland as a migration, resting and opportunistic feeding ground and define percentage of migrating whales utilising regions such as the Gold Coast bay
understanding the relationship between movement of Humpback Whales and physical water properties in particular flow
understanding and mitigating impacts of urbanisation on the behavioural response of Humpback Whales (shark nets, boats, constructions, noise)
observingindividual life histories, social role, habitat use, reproductive statusand mating systems
developing analytical methodsfor skin biopsyand mucous sampling
determining pathogens, health and decomposition through examination and sampling of deceased animals
The gathered information on Humpback Whale provides the base for recommendations for whale conservation and management strategies for relevant management bodies to maintain the conservation value of resting areas.
Methods
Surveys
Visual surveys are undertaken through land, boat and aerial based observationin south-east Queensland recording abundance, distribution and behaviour of Humpback Whales in particular within the 3nm zone. Data is being collected through specifically designedsoftware applications and photographs of flukes and scars.The survey includes the counting number and type of boats (engines), recording boat strike marks, attempted predation (shark bites) or direct recreational diver/boat interactions. Photographs of flukes and scarsallow identifying of individuals and determination of individual life histories, social role, migration, habitat use, distribution, and reproductive status.Boat based surveys are undertaken daily for up to 5 hours during whale migration. The location of each sighted whale is determined within a range of 10 m and entered into a GIS based spatial data system. Photographs of flukes are compared using the software “Fluke Matcher” with other available data collections from the east-coast of Australia (Byron Bay, Point Lookout, Hervey Bay). Videos taken during the boat and air based surveys are used to assist in determining behaviour, sex and individuals. Air based surveys are undertaken using drones with high resolution photography and video to count whales and boats throughout a grid system at randomly allocated time intervals.
Land based surveysare undertaken using survey sheets and Theodolites in conjunction with Software for tracking whales. Simple survey sheets are also given to people who randomly use the coastal area for recreational purposes. Data sheets are collected at the end of each whale season and entered into the data base.The information gathered during the surveys are analysed for abundance and distribution of whales, relationship to physical parameters and behaviour.
Behavioural responses are for instance a demonstrable change in the activity of an animal in response to a sound or visual contact. These effects can be difficult to detect due to the cryptic and variable nature of cetacean behaviour, but they can indeed be demonstrated with careful data collection. Examples of behavioural effects include the abandonment of an important activity (e.g. resting) or location (Nowacek et al., 2007). Other more obvious behavioural activities can be related to the mating system. Previous observations at Hawaii wintering grounds have shown that males swim along with preferable large females in different groups. A primary escort spends most of the time close to the female and a secondary escort associates from time to time and experiences strong competitive behaviour (Pack et al., 2009). Such activities are likely to be identified during the migration as well.
Underwater video recording
National Geographic’s Crittercam, a video recording system, documents on the behaviour of individuals and allows establishing of short term tracksby collecting speed, depth, temperature and direction. National Geographic’s Crittercam is used as a data collector to investigate short-term behavioural changes. Crittercam has been applied successfully on Humpback Whales in Hawaii and Canada using a suction cup to attach the unit. The system records video and audio data and information on depth, temperature, salinity, direction and flow and can help to define certain water quality preferences. Crittercam combines data with imagery and makes the observation of short-term behavioral changes possible. This includes the observation of resting, nursing, competitive behaviour and potential predator. In addition, the gained data will be compared with previous results from Hawaii and Canada to confirm and add to current knowledge.
Crittercam is deployed using a small and mobile vessel and trained operators. During the deployment trials, under water video is taken to determine size and possible sex of individual whales. After successful deployment of Crittercam the recording system remains with the animals for up to two hours and is collected using a VH frequency. The research vessel stays within 500m of the emitted signal to avoid interference.
The tracks of individuals are combined with collected water property information such as currents, temperature, depth and sound and analysed for relationships and behaviour.
Satellite tagging
Satellite tagging is envisaged to be used either in conjunction with other research projects on the east coast of Australia or as stand-alone when funding is available. Satellite tagging can reveal movement behaviour previously unknown and over significantly longer time periods than suction cup tags. A small number of humpback whales are to be satellite tagged to provide longer term information on the movement patterns of humpback whales in particular during southern migration. Data from previous research efforts does not provide the fine scale resolution required to validate movement models. Satellite tags are the only available methods to allow weeks or month of movement observations in particular in regards to current and temperature changes.
Acoustics
Certain frequencies of sound will be recorded by small hydrophones used for boat noise level determination. Sound is also collected using Crittercam during deployments and will be recorded for the main frequencies of the most common engines.Further sound is recorded by passive acoustic receivers along the coastline.
Skin biopsy and blow sampling
During boat based surveys whale flakes may be collected when available to allow for skin biopsy. However, shedding in subtropical waters is minimal compared to temparate waters. Skin will therefore be collected from the tag used to deploy Crittercam if available. Sex and age determination as well as individual identification can be undertaken using genetics to supplement the Crittercam and survey information. The length of telemores in chromosomes are analysed to determine age and the chromosomes to determine sex (Gillett et al., 2008; Jayasankar et al., 2008). Spray from the blow of whales is collected using a small, light-weight drone and specifically designed collector (Acevedo-Whitehouse et al., 2010). The drone is operated from the vessel during deployment for a maximum of 10 minutes and navigated near the whale when exhaling and no closer than 10 m directly above the animal. A distance of more than 100 m to the whales is being kept. The spray is analysed for pathogens (bacteria), hormones and male/female whale DNA.
Water properties
A fine-scale model or spatial resolution of water column profile data including current velocity and direction, depth, temperature, salinity, turbidity, chlorophyll and turbulence is developed. The physical parameters to be measured include water column profile data (current velocity and direction),to be collected bystationary, bottom mounted ADCPs (Acoustic Doppler Current Profilers) and ADCP transect lines from a moving vessel if possible (environment dependant). Furthermore we plan to undertake spot downcasts of CTD (conductivity, temperature, depth), salinity, light penetration, turbidity, chlorophyll and turbulence throughout the water column from a vessel.
The surveys will be undertaken during the south (May-June) and northward migration (September-October). In addition GPS fitted drifter or dissolvable drifters are released during the deployment of Crittercam and water profile measurements are taken to measure surface currents.
Necropsies
Stranded and floating deceased whales are sampled for skin, blubber and when available blood to analyse for pathogens and possible malnutrition. Standard measures are taken and when feasible the carcass is examined in detail for internal injuries and signs of infection. Floating deceased animals are fitted with data loggers to determine rate of decomposition and direction of movement assisting with health assessments and stranding management.
Principal Investigator
Dr Jan-Olaf Meynecke (Research Fellow, Griffith University)
Current Partners & Collaborators
Griffith Climate Change Response Program
Griffith Centre for Coastal Management
Griffith Australian Rivers Institute/Smart Water Research Facility
SCU Whale Research Center
Oceania Project
Friends of Federation Walk
Humpbacks & High-Rises
Whales in Paradise
Spirit of the Gold Coast Whale Watching
Coolangatta Whale Watching
Whale Watching Gold Coast/Tallship
National Geographic
Gold Coast City Council
SEQ Catchments
Surfrider Foundation Gold Coast
Cost & Duration
- not available in this version-
References
ABS, 2008. Year Book Australia, 2008. Australian Bureau of Statistics, Canberra, Australia
Acevedo-Whitehouse, K.A., Rocha-Gosselin, A., Gendron, D., 2010. A novel non-invasive tool for disease surveillance of free- ranging whales and its relevance to conservation programs. Animal Conservation 13, 217–225.
Chilvers, B.L., Lawler, I.R., Macknight, F., Marsh, H., Noad, M., Paterson, R., 2005. Moreton Bay, Queensland, Australia: an example of the co-existence of significant marine mammal populations and large-scale coastal development. Biological Conservation 122, 559-571.
Clapham, P.J., 2000. Cetacean Societies Ill. In: Mann, J.C., Connor, R.C., Tyack, P.L., Whitehead, H. (Eds), The humpback whale. University of Chicago Press, Chicago,173-196.
DEW, 2007. Draft East Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems,Conservation Values and Uses of the East Marine Region. Department of the Environment and Water Resources, Canberra,
DEWR, 2007. The Humpback Whales of Eastern Australia. [Online]. Available from: [Accessed: 06-Jan-2009]. Department of Environment and Water Resources
Dunlop, R.A., Cato, D.H., Noad, M.J., 2008. Non-song acoustic communication in migrating humpback whales (Megaptera novaeangliae). Marine Mammal Science 24, 613-629.
Franklin, W., 2014. Abundance, population dynamics, reproduction, rates of population increase and migration linkages of eastern Australian humpback whales (Megaptera novaeangliae) utilising Hervey Bay, Queensland. PhD thesis, Southern Cross University, Lismore, NSW.
Gillett, R.M., White, B.N., Rolland, R.M., 2008. Quantification and genetic profiling of DNA isolated from free-floating feces of the North Atlantic right whale (Eubalaena glacialis). Marine Mammal Science 24, 341-355.
Gribble, N.A., McPherson, G., Lane, B., 1998. Effect of the Queensland Shark Control Program on non-target species: whale, dugong, turtle and dolphin: a review. Marine and Freshwater Research 49, 645-651.
Hester, K.C., Peltzer, E.T., Kirkwood, W.J., Brewer, P.G., 2008. Unanticipated consequences of ocean acidification: A noisier ocean at lower pH. Geophysical Research Letters 35, 196 - 201.
Hilton-Taylor, C.c., 2000. IUCN Red List of Threatened Species. IUCN/SSC, Gland, Switzerland and Cambridge, UK.,
Jackson, R.B., Carpenter, S.R., Dahm, C.N., McKnight, D.M., Naiman, R.J., Postel, S.L., Running, S.W., 2001. Water in a changing world. Ecological Applications 11, 1027-1045.
Jayasankar, P., Anoop, B., Rajagopalan, M., 2008. PCR-based sex determination of cetaceans and dugong from the Indian seas. Current Science 94, 1513-1516.
Lammers, M.O., Brainard, R.E., Au, W.W.L., Mooney, T.A., Wong, K., 2008. An Ecological Acoustic Recorder (EAR) for long-term monitoring of biological and anthropogenic sounds on coral reefs and other marine habitats. Journal of the Acoustic Society of America 123, 1720-1728.
Lynch, H.J., Fagan, W.F., 2009. Survivorship curves and their impact on the
estimation of maximum population growth rates. Ecology. 90(4):1116-24.
Meynecke, J.-O., Meager, J., 2016. Understanding strandings: 25 years of humpback whale strandings (Megaptera novaengliae) in Queensland, Australia. In: Vila-Concejo, A.;Bruce, E.; Kennedy, D.M.; McCaroll, R.J. (eds). Proceddings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, 75, 897-901.
Meynecke, J.-O., Vindenes, S., Teixeira, D., 2012. Monitoring humpback whale (Megaptera novaeangliae) behaviour in a highly urbanised coastline: Gold Coast, Australia. In: Moksness E, Dahl E, Støttrup J (eds) Global Challenges in Integrated Coastal Zone Management - 2nd edition. Wiley-Blackwell Ltd.
Noad, M., Dunlop, R.A., Cato, D.C., Paton, D., 2008. Abundance estimates of the east
Australian humpback whale population: final report for the Commonwealth
Department of the Environment, Heritage, Water and the Arts. University of