Thursday, May 28, 2009

Indo-pacific dolphins sighted at Bramston Beach

Last Sunday I was keen on a beach walk. Perhaps I needed to thaw the cold that had crept into my bones during a recent visit to Victoria or maybe it was the perfect blue skies but the urge to visit salt water could not be ignored!

The tide was out and the ocean was very calm considering it was almost midday. As usual I scanned the ocean hoping to see a sea eagle or dolphin.

At the start of the walk I made my usual remark to Sara about how I am the only person in north Queensland who hasn’t seen a wild dolphin at the beach.

Well that all changed in an instant when a dolphin launched itself into the air like a polaris missile and crashed back into the water.

I could not believe my eyes!

For 10 minutes we stood there spellbound as 4 or 5 of these magical creatures casually passed us heading south toward Ella Bay 7 km away.

These days I rarely go anywhere without my camera as North Queensland has a habit of throwing little surprises like this at you and it pays to be ready.

I snapped away like a madman and could not wait to get home and check out my photos.

Once I had downloaded the photos I discovered that my dolphins were not the common bottlenose dolphin but they were Indo-Pacific humpback dolphins (Sousa chinensis). The Queensland Nature Conservation Act 1992 lists Indo-Pacific humpback dolphins as a rare species.

I emailed marine biologist Blanche Danastas at Marine Wildlife Australia and she confirmed they were indeed humpback dolphins after examining my photos. Blanche asked me to fill out a report which I downloaded from the MWA website(PDF) as these marine mammals are poorly understood. This became obvious to me when I researched this species and I often came across the words “data deficient”

Indo-Pacific humpback dolphins are classed as a coastal species as they are usually found within 10 km of the shore.
Photo by Dr Guido Parra 2009

It was exciting to read that Australian humpback dolphins may be a distinct Australian species according to recent DNA testing. Scientists Celine H Frere, Peter T Hale, Lindsay Porter, Victor G Cockcroft and Merel L Dalebout state “Results strongly suggest that the Australian humpback dolphins are not S chinensis but may represent a distinct species in their own right” (on the CSIRO website).

It’s interesting to note that the Australian snubfin dolphin, another coastal dolphin found at Ella Bay and Bramston Beach was believed to be the more widespread Irrawaddy Dolphin until recently. Studies and DNA testing of snubfin dolphins at Townsville confirmed the Australian snubfin is a distinct species. I suppose time and further study will reveal if our own humpback dolphin is also a distinct Australian species.

Photo by Daniele Cagnazzi 2009

Humpback dolphins are generally found in less than 15 metres of water but prefer to feed in 2-5 metres of water Para 2006. They are usually found within 20 km of a river mouth. The pod I photographed were approximately 15 km north of the mouth of the Johnstone river mouth near Innisfail.

Humpback dolphins face threats from human activity as they live in the same inshore coastal areas that are often heavily used (and abused) by our own species. As such they deserve special attention. The Great Barrier Reef Marine Park Authority states
“While all species of dolphin are protected in the Great Barrier Reef Marine Park, there are two species that the GBRMPA currently considers as high priority for management. The Australian snubfin dolphin (formerly known as the Irrawaddy dolphin) and the Indo-Pacific humpback dolphin are two species that live in the inshore waters of the Queensland coast. There is concern that the population numbers of these species throughout the waters of northern Australia are in decline. As these dolphins often inhabit waters in areas where there are high levels human activity, they may be vulnerable to impacts from a range of human activities such as boating, netting and poor water quality caused by run-off from the land. Research is currently being undertaken on the population status, biology and potential threats to both these species.”
These local humpback dolphins are likely to be negatively affected by the massive urban development/resort complex that property developer Satori has proposed for Ella Bay.

Satori estimates that they will increase this fragile bays population from less than a dozen people to approximately 5000 people. If this development is permitted the Ella Bay region can expect a massive increase in marine traffic. This traffic will include activities such as recreational boating, water skiing, jet skiing and parasailing. All these activities will disrupt normal dolphin use of this habitat. Boat strike, pollution, intentional and unintentional harassment could severely threaten humpback dolphins in this region.

A massive stinger net depicted within Satori’s EIS represents a direct infringement on the feeding territory of humpback dolphins at Ella Bay (as I have previously mentioned this species prefers to feed at depths between 2 and 5 metres, Para 2006 ).

Federal Environment Minister Peter Garrett AM MP Has received formal legal requests from CAFNEC and The Environmental Defenders Office to consider the needs of marine species such as coastal dolphins, dugongs and marine turtles when assessing Satori’s development proposals for Ella Bay. They have also formally requested that the marine environment be considered when assessing development at Ella Bay. Indeed BAAM the developers environmental consultants have stated “BAAM (2006) did not address purely marine species, which should be the subject of assessment by marine experts.” (Full report, PDF).

I hope Federal Environment Minister Peter Garrett AM MP has the courage and wisdom to protect this marine habitat not just for the humpback dolphins but for all the amazing marine species that need this wilderness area if they are to have a future in this region.

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