Capricorn Cetacean Project Crew Like for the MUCRU team in Western Australia It has been a busy start to the season for Capricorn Cetacean Research Project along the Queensland coast, winds mostly below 10 knots and sunny conditions…dream conditions for any researcher! The new volunteers, Kelly (Washington, USA), Kate (Missouri, USA) and Letizia (Umbria, Italy), after landing from their long flights, had only few days of rest before embarking on the first of two, one-week expeditions to Broad Sound, an extremely remote bay in Central Queensland (Australia).
Never before has there been a dedicated boat based survey for inshore dolphins conducted in Broad Sound. The primary aim of these expeditions was to identify potential critical habitats for Indo-Pacific humpback and Australian snubfin dolphins to increase our understanding of their abundance and distribution in Australian waters. Broad Sound is a large north facing V-shape bay, about 50 km long and 20 km wide. Tides flood toward Broad Sound from the north and from the south, resulting in a local magnification of the semi-diurnal tides by a factor of 6 compared to those elsewhere on the east Australian coast. The head of the bay has the greatest tidal range on Australia’s east coast reaching up to 9 m leaving all the creeks flowing into the bay (Styx River, St. Lawrence creek, Waverly Creek and Herbert Creek) entirely dried for most of the day. As a result of the high tidal range and turbidity seagrass does not grow in Broad Sound.
Map of Broad Sound. Locations of schools of humpback and snubfin dolphins are indicated with red and blue squares respectively
Adori Because of its isolation and limited accessibility, this bay can only be safely reached by water. The journey from Rosslyn Bay, 100 nautical miles south of Broad Sound, was long (14 hrs) but fun.
In transit, we relaxed on board the slow but comfortable Adori, a 17 m ship masterfully streamed by its skipper John. While travelling toward our destination, the crew witnessed a large number of migrating humpback whales, which made for a very exciting first day.
Thanks to favorable weather conditions we were able to complete 10 out of the 13 days with perfect sighting conditions. Over this period we searched on and off efforts for about 106 hrs and did almost 700 km of survey effort. During these surveys, a small group of friendly professional fishermen was the only human presence in the area.
In transit, we relaxed on board the slow but comfortable Adori, a 17 m ship masterfully streamed by its skipper John. While travelling toward our destination, the crew witnessed a large number of migrating humpback whales, which made for a very exciting first day.
Thanks to favorable weather conditions we were able to complete 10 out of the 13 days with perfect sighting conditions. Over this period we searched on and off efforts for about 106 hrs and did almost 700 km of survey effort. During these surveys, a small group of friendly professional fishermen was the only human presence in the area.
Unfortunately the results were not exciting; only 9 small schools of dolphins were sighted (including two resightings of the same schools), four of which were sighted on the same day. The most observed species was the Indo-Pacific humpback dolphin, with 6 sightings, while only 3 schools of Australian snubfin dolphin were observed. All records occurred north of the Styx River where waters are clearer and less affected by the strong tidal currents.
Humpback and snubfin dolphin
Thanks to the team for their hard work, even though exciting events were few and far between. Special thanks to Adori, its skipper John and second in command Ginny, together with FBA representatives Tom and Shane, who provided a valuable contribution to this research through direct contribution to the fieldwork, logistical support and great food.
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