Bremer Canyon Killer Whales - Season 2024
Dave Riggs has been visiting the killer whales of Bremer Canyon for almost 20 years and is credited with first recognizing the potential of this amazing location as a marine biodiversity hotspot.
His first trip out to the area was in 2005 when he was contracted to act as a wildlife observer onboard a Japanese southern bluefin tuna research expedition.
The expeditions were conducted each summer and covered over 1000 nautical miles of ocean between Albany and Esperance.
The personnel onboard the expedition generally consisted of 2 Japanese scientists, a skipper and Dave.
Most of the journey saw the team traversing miles of ocean without seeing more than occasional flocks of flesh footed shear water, occasional albatross, small pods of common dolphin and schools of tuna which tended to congregate on inshore reefs and the edge of the continental shelf.
Each summer the team made a number of excursions over the edge of the continental shelf adjacent to Albany, Cheynes Beach and Bremer Bay. These excursions were pre-planned and rarely was the ‘transect line’ broken. One of these transects saw them pass close by the killer whale hot spot offshore Bremer Bay (at this time it was unknown). It was here that Dave began noticing more life than he was observing in any other part of ocean they were traversing. Killer whales were occasionally observed as they passed by but it was the strange smell permeating the area that really caught his attention. We now know that smell is from freshly killed beaked whales.
Dave was onboard the blue fin tuna survey each summer between 2005-2013 and over time, he became convinced there was something special about the place we now regularly see the Bremer killer whales.
In early 2010 the area offshore Albany to Esperance was seismically surveyed for oil and gas over a period of 6 weeks. Dave managed to source a document from the proponent that containing not only information on a possible commercial quantity of oil and gas but also all the sightings of marine life observed during their survey.
The sightings of marine life made by the oil and gas explorers further fuelled his suspicions of a ‘hotspot’. They had also documented more life in one particular area than they observed elsewhere. The oil and gas observations were conducted by an independent company brought onboard from the UK. Now that the explorers had confirmed the likelihood of a commercial quantity of oil and gas in their tenement, their next move was to conduct a more extensive 3d seismic survey to further refine their understanding of the sub sea geology. They also planned to sink two exploratory wells, one in close proximity to the apparent aggregation of marine life (at this stage there was still no recognition of a concentration of marine life).
Understandably Dave was concerned. There was no effort being given to research the apparent ‘hotspot’ prior to high powered seismic or the establishment of a well. It truly seemed as though this amazing place would be extinguished before it was even recognized as existing.
Rewind to September 2003 and the now infamous sperm whale stranding at ‘Hebs Beach’.Dave and his wife Jennene had travelled from Esperance to film the reported stranding of 9 pregnant sperm whales. They were working as part of a CSIRO team who were spearheading Australia’s first large scale white shark tagging project.Dave and Jennene were employed to document each tagging expedition for CSIRO’s animal ethics and had been doing so since 2000. A number of sharks were tagging with both pop off archival and satellite tags during their week long expedition to the sperm whale stranding.One of these sharks, a 3.2 metre female known as ‘shark Alpha’ was fitted with an acoustic tag that was retrieved several months after the stranding. The data it recorded seemed to indicate it had been consumed by a large predator in close proximity to the (theorized) killer whale ‘hot spot’.This unprecedented event wasn’t publicly reported and became a point of fascination to Dave. Fast forward to 2011 and Dave, as a final ditch effort to highlight the potential marine life aggregation (before drilling commenced) wrote a proposal for a documentary to ABC TV. The thrust of the film was shark Alpha and what marine creature could have been responsible for her demise. Possible perpetrators included killer whales, sperm whales, giant squid and white sharks. ABC funded Dave’s expedition and he and his team headed for Bremer onboard their filming vessel in January 2013. This vessel was later acquired by Naturaliste Charters and is now the pride of their fleet.
The filming expedition commenced with a boat journey from Dave’s hometown of Esperance to Bremer which was conducted at night and in pretty awful conditions. A strong southerly wind whipping up 3 metre swells which saw the team unable to rest for the entire journey. Dawn saw them some 30NM east of the hot spot so the vessel was slowed and all eyes were on the water for signs of life, specifically killer whales.The next 3 hours observation yielded nothing. The entire crew were skeptical of Dave’s suggestion there was a hot spot somewhere ahead and most went downstairs to the relative comfort of the saloon where they attempted to rest. At one point a scientist mentioned to Dave it was highly unlikely they would find his fabled hotspot of marine life, there’s no way it could have gone undiscovered until now. It was, after all, right in the middle of an international shipping channel! Beginning to doubt himself, he remained in the wheelhouse peering into the rough lifeless ocean, desperately searching for a sign of anything! Maybe there wasn’t a hot spot at all?Then it happened, 500 metres from the ‘hot spot’ the ocean erupted into life. Dozens of killer whales materialised out of thin air and it was on! Non believers were instantly on the deck and gazing in awe at the spectacle. Dave reckons at that moment he felt his heart rate drop from 120 to 60 in the blink of an eye! For the next 3 weeks the film crew documented consistent killer whale activity at the hot spot. It was finally confirmed to exist! Dave had been documenting whatever he saw during the tuna survey and upon comparing his killer whale images with those taken during the filming expedition it became clear that the same animals were visiting the location year after year. The killer whale identification catalogue we have today was started in these early years of opportunistic observations. It has now been developed to a point where we know there are at least 200 individuals frequenting the site.
Dave’s film was released on ABC on the 3rd November 2013, it was entitled ‘The Search for the Oceans Super Predator’. It was then screened in mid 2014 in North America on Smithsonian. From here reversions were made and it ran in countries all over the world. Everyone wanted to know ‘What ate shark Alpha?’Immediately after the initial ABC screening, Dave started fielding a stream of inquiries from people wanting to visit the killer whale hot spot for themselves. At this point he had no way of accommodating them as he didn’t have a suitable charter boat. One of his friends who happened to watch his film decided to help out and loaned him his 20 metre ex-fisheries patrol boat.Now with a means of getting out on the ocean, he launched a crowd funding campaign that he hoped would fund his 2014 expedition, this was in late December 2013. The campaign was successful and he, 300 passengers and a small team of scientists began daily visits to the killer whales in late January 2014.
On the 25th February we witnessed the first ever beaked whale predation by killer whales in Australian waters. This led to the publication of a scientific paper, further illuminating the importance of the location.With a spotlight suddenly thrust on the Bremer killer whales, the oil and gas proponent decided to relinquish. their tenement. There was now an opportunity to try for protection of the site. Dave had recently been in contact with Federal MP Rick Wilson via his science advisor Lesley Arnott and together they began highlighting the location to then environment minister Greg Hunt. It took several years of persistence but finally a portion of the ‘hot spot’ received a degree of protection. Importantly, protection from future oil and gas exploration.There is a whole lot more to Bremer’s incredible killer whale hot spot, this is just the tip of the iceberg.
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