Port Stephens Pelagic Trip Report - Sun 12th December 2010
Boat: M.V.Argonaut, skippered by Ray Horsefield
Too good! A gentle westerly was in our backs as we crossed the sea that had an approximate 0.5m swell. Not far from the shelf the influence of the offshore breeze dropped off completely such that the sea surface was very smooth once in the deep water. This was to be the trend for the day until a welcome nor-easter hit us when we were about 4 miles from the heads (and which appeared to spring the birds into action). Water temperature at the shelf not noted but the presence of species such as Dolphinfish and Pan-tropical Bottlenose Dolphins a good sign that it was at least in the low 20’s.
Interestingly, a recent unrelenting bout of nor-easters had potentially caused (via Coriolis effects and Ekman transport phenomenon) the warm water currents that had been pushing down the NSW coast to remain eastwards of the shelf
break, with cold (reportedly as low as 15 degrees) water persisting near the coast south of about Port Macquarie (much to the ire of my surfer mates). I mused that such an effect could work favourably in terms of sea-surface food (i.e. cold water meeting warm water and resulting in upwelling of nutrients) and according to the MHL maps these waters met right at the shelf. The large number of sea creatures at the shelf could have been a result of this? If anyone has a theory or input into this I’d be very interested to hear it.
The fish and mammals. There were no clear avian highlights on this trip, apart perhaps from the good numbers of Pomarine Jaegers at the back of the boat once the Shearwaters decided to start feeding close to port.
Departed Nelson Bay Public Wharf at 0710, returning at 1745.
After some initial interest shown by a couple of Arctic and Pomarine Jaegers, it was a very lonely trip out for the Argonaut and the punters. In fact, it stayed that way for virtually the whole day. Two Wandering Albatross were seen distantly sitting on the water about half-way out, and aside from the occasional Wedge-tailed or Short-tailed Shearwater flying past, these were the only birds
seen en-route to close to the drop-off.
Just short of the shelf break a few White-faced Storm-petrels were seen feeding along a current line, but we decided to push on into deeper water. A drift was set-up at 32 56 49 / 152 33 47 and almost at the instant that we did a Sooty Shearwater zoomed past. But for the next 90 minutes or so not a single bird came in to the back of the boat. There was barely any activity in the slick, apart from some incidental Wedge-tailed Shearwaters and White-faced Stormies. A large pod of Risso’s Dolphins cruised past not long after our arrival and at one point a medium-sized shark (probable Whaler, possibly Black) cruised up to boat to check us out. But for birds it was one of those days when set the slick and berley trail up and you wait for birds to come to you. It never happened. The conditions were decidedly calm and we all willed on the nor-easter forecast to hit during the afternoon.
After reaching 33 01 48 / 152 31 47 we decided to head back to the current line where the Stormies had been bouncing around and although there was more activity at this spot, it was still a big zero for birds behind the boat. We did add Wilson’s Storm-petrel (2) and Flesh-footed Shearwater (1) to the day’s list here. Finally, the only Pterodroma for the day, in the form of a Great-winged
(Grey-faced) Petrel came and went. The highlight however, was an extensive, loose pod of Pan-tropical Spotted Dolphins that moved through and stretched across quite a section of ocean to the east. A single Dolphinfish showed interest in the boat and along with the dolphins was an indication of warm water in the vicinity.
Feeling a little deflated at the almost absolute lack of birds, we headed back for port. In a great twist, about 4 miles from the heads (and almost at the exact moment the nor-easter got up) we were suddenly descended upon by a couple of hundred Wedge-tailed Shearwaters and a dozen or so Fleshy-foots. Good numbers of Pomarine Jaegers then came in, along with an immature Black-browed Albatross, a Hutton’s Shearwater, a couple more Sooty Shearwaters and a handful of Crested Terns – there was now a complete frenzy behind the stern! We enjoyed this spectacle until we rounded Point Stephens (especially one passenger who was on their maiden pelagic).
Species: Approximate total (maximum number around the boat at one time)
White-faced Storm-petrel: 15 (4)
Wilson’s Storm-petrel: 2 (2)
Black-browed Albatross: 1
Wandering Albatross: 2 (1)
Hutton’s Shearwater: 1
Wedge-tailed Shearwater: 250 (200)
Flesh-footed Shearwater: 11 (10)
Short-tailed Shearwater: 5 (1)
Sooty Shearwater: 3 (1)
Great-winged (Grey-faced) Petrel: 1
Australasian Gannet: 10 (8)
Crested Tern: 7 (4)
Pomarine Jaeger: 14 (7)
Arctic Jaeger: 5 (2)
Inshore Bottlenose Dolphin: 12
Indo-Pacific Bottlenose Dolphin: 20
Risso’s Dolphin: 40
Pan-tropical Spotted Dolphin: 200+
Hammerhead Shark: 1
(Black?) Whaler Shark: 1