Whales, Wildlife & Wilderness                                                                                                                                                 Pam & Wayne Osborn

Humpback Whales - Exmouth Gulf

 

Gimme Shelter - Exmouth Gulf

 

The title Gimme Shelter is an old Rolling Stones anthem from their 1969 album 'Let it Bleed.' In 1969 when some of us were proudly spinning the Stone's vinyl at 33 rpm on our turntables, humpback whales were slowly crawling back from the precipice of extinction. It has been a remarkable recovery and these guys do deserve a bit of 'Gimme Shelter' in the resting grounds of Exmouth Gulf.

 

Each year in September and October they come. The great southbound migration of the the largest group of humpback whales on the planet. Exmouth Gulf is a save haven for the calves. It's a time to rest, to practice life critical skills and build blubber reserves.

 

Exmouth Gulf is remote. It is 1300 kilometres north of Perth, Western Australia's capitial city To the east is the arid ancient landscape of the Pilbara. Fractured rock, spinifex grass and dry watercourses predominate.

 

The narrow spine of Cape Range frames the western boundary of the gulf and gives way to the fringing coral reef known as Ningaloo.

 

 

Accidental Photographers

 

We visited Exmouth in 2006 and have returned each year to photograph the humpbacks. Our first visit was really to SCUBA dive the reefs but the whales proved to be irresistible distraction.  In 2007 we met whale researchers Curt and Micheline Jenner, founders of the Centre for Whale Research WA (www.cwr.org.au). They gently suggested that if we wanted to be useful, we could photograph whales in accordance with the protocols for their humpback identification catalogue.  We took their advice.

 

Since 2006 we have travelled 2400 nautical miles in Exmouth Gulf and photographed 2397 whales. 710 of these were mothers with new season calves.  We have also photographed humpbacks off Shark Bay, Ningaloo Reef, Perth Waters and Rottnest Island for the CWR catalogue.

2013 GPS Waypoints

 

We record GPS tracks  for each day and the geo-location position is transferred to each whale photograph.  This image shows a GPS waypoint for each pod in 2013. We travelled 382 nautical miles and photographed 443 whales in 157 pods. 71 pods were mothers with new-season calves, 54 pods (non-calf) had multiple whales and 28 whales were solitary.

 

The waypoints show a strong concentration within a 5 nautical mile range of the Exmouth Marina.  This is a little tighter pattern than our prior year sightings which have extended to the north past the tip of the North West Cape and further south to te Learmonth Airport.

 

Whilst it is not a population survey, it does indicate high whale densities in a area which is also used for commercial and recreational shipping.  These pressures have recently increased with Exmouth being used as a supply base for for offshore oil and gas exploration and extraction.

Shared Waters - Can They Get The Kids to Sleep?

 

Exmouth is enjoying the benefits of increased economic activity which manifests in more shipping traffic as the whale population also grows.

 

Researchers are trying to estimate the carrying capacity of the gulf in terms of just how many whales can effectively use the gulf and still gain the benefits of it being a rest area.

 

The mothers are fasting since leaving Antarctica 5 months earlier and have finite blubber reserves to produce the fat rich milk for their offspring. the calves are curious and like children are stimulated by the human induced activity around them.  Keeping the kids quiet is a big challenge for mum.

Southern Right Whales - Rare Visitors

 

We have only seen three southern right whales in Exmouth Gulf.  In each case it was a mother and new-season calf.  Southern rights usually don't get much further north than the waters off Perth but in each case these mothers were also using the gulf as a resting ground.

Western Australian Coastline

 

This map shows the location of the birthing grounds of Camden Sound in the Kimberley and the resting grounds of Exmouth Gulf, 1200 kilometres to the south west.