FPSO Monitoring Project
While working off the Dampier Archipelago in the early 1990’s, we often wished we could winch our small inflatable aboard one of the iron ore bulk carriers that regularly anchored in the whales’ migratory path so that we could spend more time conducting our research and less time to-ing and fro-ing from our island base at Enderby. When a photo showing a pair of humpback whales next to the Griffin Venture was emailed to us in 2004, this idea was re-kindled!
FPSO (Floating Production Storage and Offloading) faciliites are basically oil tankers that are moored to the ocean floor above a series of producing oil and/or gas wells. Oil and gas is piped aboard the vessel for primary processing and separation and then either stored onboard until another oil tanker comes to offload the cargo, or, in the case of gas, is piped ashore.
Since 1998 the CWR has had an active interest in how Exmouth Gulf is used by humpback whales. The Gulf appears to be a major resting area for southbound cow/calf pods in this population and perhaps represents the highest annual concentration of calves in this population throughout its entire range. The Griffin Venture(BHPB) is situated north of Exmouth Gulf and is in an ideal position to observe the transition period between the northern migration of this species towards its Kimberley calving grounds, and the southern migration which proceeds in 2 distinct phases (see figure). The first phase includes adult whales, and in particular mature females likely to be in estrous, while the second phase contains mature females with calves of the season. Both groups are followed by male whales, intent on mating, which use a combination of fighting and singing to repel competitors and attract prospective mates.
Role of the FPSO CrewBy documenting the numbers (and species) of whales traveling north or south as the season progresses (June to November) researchers can establish how consistent the timing is between consecutive seasons and build a data set that can be used to draw conclusions about the length of time the whales spend feeding in Antarctic waters each year, and even the effect of human disturbance on their movements. In order to monitor the progression of the migration from the northern migration through to the 2 phases of the southern migration, it is necessary to collect data in a consistent form that will allow a pattern to emerge. These two FPSO’s are in a unique position geographically where both the northern and southern migrations can be observed. Statistically sound conclusions can be drawn from the data if a record of the amount of sighting effort is recorded along with all sightings
The FPSO sightings will give us a “whales per unit effort” curve that will document the peak of season (expected during the late August time period) as well as a cross-over curve that will indicate the period when equal numbers of whales are heading north as those heading south . These time periods are important because they indicate how stable the migration is from season to season and will give researchers an indication of how humans or other dynamics may be limiting the recovery of this species.