A small pod of white-beaked dolphins entrapped on Friday (10 March) by a sudden surge of ice along the northern Newfoundland coast were lucky to have been rescued by humans before polar bears could get to them. We know the bears are around, drawn south by the millions of harp seals giving birth to their pups in the area. In April 2014, something similar happened to white-beaked dolphins in Svalbard and they became a welcome meal for at least six polar bears (Aars et al. 2015).
Ice-entrapped dolphins rescued
According to NOAA:
White-beaked dolphins are found throughout the cold waters of the North Atlantic Ocean. They are active swimmers and often “surf” the waves created by vessels. They are usually found in groups of five to 30 individuals but sometimes travel in groups of up to 1,500.
White-beaked dolphins hunt for food both near the water’s surface and along the ocean bottom. Some fishermen in Canada call these dolphins “squidhounds” because they eat squid and octopi.
From a VCOM News report yesterday (11 March 2023):
It appears most of the dolphins trapped along the shoreline in Trinity Bay ice on Friday may have found a path to safety.
About 15 of the white-beaked mammals were first spotted in trouble on Friday morning off Heart’s Delight-Islington.
Residents, assisted by the local fire department and DFO., quickly sprang into action, moving some from one side of the harbour to the other. Wayne Ledwell, with the Whale Release and Strandings Group, was also on the scene, and described the effort to move three of the dolphins to open water a little farther away.
He says they were stabilized in the water before someone suggested using a snowmobile sled, used for hauling wood, to hoist them into the back of a truck. They were then driven to nearby Whiteway where the process was reversed on the slipway, and they were released again into ice-free water.
It’s believed two or three in the original pod may have perished as they were forced closer to shore by the jagged ice.
Ledwell says others were spotted moving through a path to open water this morning, but he notes they’ll still have to deal with heavy pack ice further offshore.
White-beaked dolphins are common in Newfoundland waters.
A similar situation involving a half dozen of the creatures unfolded in the same area in 2018, with a successful rescue operation that took days to complete.
Historical records indicate this is a fairly regular occurrence in Newfoundland (Hai et al. 1996).
In March 2018, excavators and boats were used to cut a path through the ice, which allowed the ice-entrapped dolphins to escape to open water, as shown in the video below.
It’s clear what happened when you look at the ice charts for the region for the days leading up to the dolphins being trapped. On Wednesday 8 March, Trinity Bay where Hearts Desire is located (map above), was largely ice-free but loosely-packed ice (light green) was moving in from the north.
By Thursday, the ice had advanced, with more compacted ice (7-8/10, orange) sealing the mouth of the bay.
By Friday, when the animals were discovered trapped in ice along the beach close to town, fairly concentrated ice had moved down the eastern shore of Trinity Bay. There was open water in the bay but no clear passage to the open ocean:
By Saturday, 11 March, the ice had moved out of the bay but the animals are still trapped within it, with fairly concentrated ice blanketing the entire area to the north.
A similar incident happened in northern Svalbard in 2014, which was blamed on global warming and attracted polar bears to feed on the trapped dolphins. The excerpt below (pg. 4) is from the paper by Jon Aars and colleagues published in 2015, which included the photo above:
Earlier observations of white-beaked dolphins as far north as northern Spitsbergen have all been made in summer and autumn (June–November; Fig. 2. Prior to this report, no recording of the species has been made in winter or spring this far north in Svalbard. The fjords and around the coast of northern Spitsbergen, an area normally covered by annual ice, were ice-free in winter 2013/14. It is likely that the presence of the dolphins in early spring was due to the lack of sea ice in the period prior to our observation. Ice maps indicated open water as late as 28 March, but dense ice in Raudfjorden from 4 April. In the period 17–18 April, strong northerly wind packed drift ice into the fjords. We speculate that this event led to the entrapment of white-beaked dolphins, including the two we found dead. Entrapment, and later suffocation, of white-beaked dolphins in areas with heavy pack ice has earlier been reported along the coast of Newfoundland.
…In Raudfjorden, at the same location as our observations in April, at least five different carcasses were observed between 2 July and 1 September. One adult male and one adult female polar bear were seen feeding on the dolphins. Farther to the west, in the bay Frambukta, one dolphin carcass was observed on 4 July, where two bears were seen feeding on it. Another carcass was found on 22 July in Liefdefjorden, to the east of the initial observations. It was scavenged by two polar bears.
The observations indicate that entrapments of pods of white-beaked dolphins may provide a significant source of food for some bears locally over a longer period of time after such an incident. [my bold]
Aars, J., Andersen, M., Breniére, A. and Blanc, S. 2015. White-beaked dolphins trapped in the ice and eaten by polar bears. Polar Research 34: 26612. Open access https://doi.org/10.3402/polar.v34.26612 Pdf here.
Polar bears (Ursus maritimus) depend on sea ice, where they hunt ice-associated seals. However, they are opportunistic predators and scavengers with a long list of known prey species. Here we report from a small fjord in Svalbard, Norwegian High Arctic, a sighting of an adult male polar bear preying on two white-beaked dolphins (Lagenorhynchus albirostris) on 23 April 2014. This is the first record of this species as polar bear prey. White-beaked dolphins are frequent visitors to Svalbard waters in summer, but have not previously been reported this far north in early spring. We suggest they were trapped in the ice after strong northerly winds the days before, and possibly killed when forced to surface for air at a small opening in the ice. The bear had consumed most parts of one dolphin. When observed he was in the process of covering the mostly intact second dolphin with snow. Such caching behaviour is generally considered untypical of polar bears. During the following ice-free summer and autumn, at least seven different white-beaked dolphin carcasses were observed in or near the same area. We suggest, based on the area and the degree to which these dolphins had decayed, that they were likely from the same pod and also suffered death due to entrapment in the ice in April. At least six different polar bears were seen scavenging on the carcasses.
Hai D.J., Lien J., Nelson D. & Curren K. 1996. A contribution to the biology of the white-beaked dolphin, Lagenorhynchus
albirostris, in waters off Newfoundland. Canadian Field-Naturalist 110: 278- 287. https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/6961312
Twenty-one ice entrapments, nine strandings and three incidental captures in fishing gear of White-beaked Dolphins (Lagenorhynchus albirostris) 1979-1990 in Newfoundland waters are summarized.
March 12, 2023 at 05:07PM