Now in its fourth year, the joint Western Australian Marine Science Institution (WAMSI) and Two Moons Whale and Marine Research Base independent humpback whale survey kicked off on Sunday 29th July 2012 at Pender Bay, located 175 km north of Broome, along the remote Kimberley coast.
The survey is a truly independent, public-good whale monitoring program for the Kimberley Coast. The clifftop survey monitors the numbers and behaviour patterns of what is now considered, the largest natural population of humpback whales (Megaptera novaeangliae) in the world which migrate from Antarctica along the Western Australian coastline to their birthing grounds in the Kimberley.
The survey builds on the previous three years of monitoring, largely unfunded, yet providing an independent assessment of the usage of Pender Bay by the Group 4, or West Coast population of humpback whales, as part of their annual migration.
Figure 1 - Map showing the location of Pender Bay
Pender Bay has long been known to be a major staging area for humpbacks. It is a place where they congregate and rest, especially mothers and calves, before travelling back to Antarctica in the September to early November period. The joint WAMSI and Two Moons research has however, already demonstrated that Pender Bay is also extremely important in its own right for birthing, mating and resting, all of which has been regularly witnessed first-hand by the research team.
Data collected from 2009 to 2011 show the number of humpback whales sighted in the area is highest in August, however the proportion of calves (to adults) is highest in September and October as the mothers nurture and teach their newborns before commencing the long migration back to Antarctica.
The overall distribution of humpback whale numbers from the last three years are presented in Figure 2 below.
Note: Figure 2 shows the average number of humpback whales sighted in any given five minute counting period that a single observer might expect to see (based on a three year sample size); i.e. all data are normalised against observer effort.
Figure 2 - Mean number of whales (normalised by viewing effort) for 2009, 2010 and 2011 at Pender Bay
These results are the culmination of 495 hours of observations over the last three years with four observers routinely recording from the remote clifftop survey site on the southern shores of Pender Bay at the Two Moons Whale and Research Base, operated by the Goojarr Goonyool Aboriginal Corporation.
The monitoring program has engaged the participation of the wider community and provided 'hands on' experience and leadership opportunities for local and international marine science interns.
Steve Blake, WAMSI CEO said, 'Without this local support from the Two Moons Team, the volunteers they provide and advice from the Goojarr Goonyool Aboriginal Corporation, we could not undertake such an important, labour intensive and cost-effective baseline data capture survey. Getting the long-term time series data is critical for informing future decisions.'
WAMSI is now formally commencing an independent, public-good marine science program in the Kimberley region, (termed the Kimberley Marine Research Program) as part of the WA State Government’s Kimberley Science and Conservation Strategy, released in May 2011.