Jean Tresfon: First Aerial Southern Right Whale Survey for 2022
"Dressed in thermal underwear, jeans, fleece, puffer jacket, flying jacket, gloves and a flight suit on top of everything else, I felt a little like the Michelin Man as I climbed into the open cockpit of my gyrocopter on Tuesday morning. The sun was barely above the horizon and the outside air temperature was showing just 5 degrees without the wind chill factor to consider. A few minutes later, with the engine warmed up and all my flight checks complete, I lifted off the ground at Morningstar Flying Club and swung the nose to the east. The next stop would be Grootbos Private Nature Reserve where I would be landing to collect whale scientist Dr. Els Vermeulen from the Mammal Research Institute Whale Unit for the first aerial southern right whale survey along the Overberg coast for 2022. There was an inversion layer and the air warmed up as I climbed through 1500ft. Heading over Sir Lowry’s Pass the Grabouw Valley was shrouded in an early morning mist. Dropping down over Arabella Golf Estate I headed for Hermanus and on to Gansbaai, landing at Grootbos not long afterwards.
After getting airborne again we headed back to Hermanus to begin the survey. The first few southern right whales were spotted immediately as we overflew the whale sanctuary area at the Klein River mouth. Two whale watching tourist vessels were already out and, passing them near Sopiesklip, we continued along the coast eastwards to Danger Point. The total count for Walker Bay was 20 cow/calf pairs and 7 unaccompanied adults for a total of 47 whales. At this stage of the season, it is still very likely that many of the unaccompanied adults are pregnant females that have yet to give birth.
Rounding Danger Point we continued past the Uilendskraal River mouth, flying over a few of the shark cage diving vessels at anchor with several sharks at the baits, before passing between Dyer Island and the mainland and arriving at Pearly Beach where we found several southern rights and another whale watching tourist vessel. Then pretty much nothing as we followed the coast past Buffelsjags, Quoin Point, Die Dam, Brandbaai, Suiderstrand, rounded the southern tip of the African continent at Agulhas and arrived at Struisbaai. In the shallows along Die Plaat we found 6 cow/calf pairs and 13 unaccompanied adults for a total of 32 whales. Continuing eastwards we routed past De Mond and on to Waenhuiskrans/Arniston were we found a small pod of humpback dolphins with some tiny calves in the shallows at Shark Bay. Further offshore we found several groups of whales dotted here and there all the way to De Hoop.
Rounding Skipskop Point we arrived at Koppie Alleen, the main nursery ground for southern right whales along the entire coast and as usual there were enough whales around to make counting a challenge. Fortunately this was not Els’ first rodeo and while I flew the plane she was frantically counting and jotting down the numbers. In that one small area we counted 150 cow/calf pairs and 9 unaccompanied adults for a total of 309 whales. Further east there were a few more southern rights as we followed the coast to Uiterstepunt and into St. Sebastian Bay, heading a few kilometres up the Breede River to our airstrip for a landing to refuel the plane, pilot and passenger.
Taking off again we counted 8 cow/calf pairs for a total of 16 whales in St Sebastian Bay before reaching the end of our survey area at Witsand. We headed back along the coast to Arniston before turning inland, flying over Elim enroute to Gansbaai and Grootbos where I landed again to refuel and deposit a chilly looking whale scientist back at her car. The last leg home saw me following the railway tracks up Houw Hoek Pass, passing the famous (and oldest) hotel of the same name on the way to Grabouw and back over Sir Lowry’s Pass, Stellenbosch and the farmlands of Durbanville before landing back at Morningstar after 7 hours in the air.
The numbers for the survey were 248 cow/calf pairs and 40 unaccompanied adults for a total of 536 whales counted between Hermanus and Witsand. As mentioned earlier a few the unaccompanied adults are likely pregnant females which have yet to give birth so the numbers will increase slightly. Although the numbers are much higher than the counts from 2019 (288 whales), 2020 (153 whales), & 2021 (368 whales), they are much lower than the record count from 2018 (1347 whales). The scientists at the MRI Whale Unit were expecting another bumper year this year based on an estimated 4-year calving cycle, so the lower-than-expected numbers are a big cause for concern. A shift to a 5-year calving cycle would indicate calf mortalities and a failure to nurse calves to term so hopefully this is not the case. There are several more surveys planned over the next few months, so we wait and see.
As always, these surveys could not happen without the help of many people. A big thank you to Michael at Grootbos for his support in allowing us to use their airstrip. A massive thank you to Lt Colonel Erwin Kotze in the tower at AFB Overberg for routing us safely through their airspace and lastly to George Filmalter for helping out with fuel logistics at Infanta."
