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Minke Whale (Balaenoptera acutorostrata) M001 lunging on a. juvenile Pacific Herring (Clupea pallasi) on 18 July 2011 and b. juvenile Pacific Sand Lance (Ammodytes personatus) on 11 June 2014. Photos: Jared Towers.
Source publication
From June to August 2012, we conducted over 500 h of visual surveys from Cormorant Island, British Columbia, to determine behaviour and habitat use patterns of nearby cetaceans. Seven species were documented, but Minke Whales (Balaenoptera acutorostrata) were by far the most common and were observed lunge feeding at the surface on 15 occasions. In...
Context in source publication
Context 1
... relation between tidal activity and the foraging behaviour or occurrence of any species was detected. Between 10 September 2010 and 7 August 2014, predation at the surface by Minke Whales around Cormorant Island was also opportunistically documented from small research vessels on 32 occasions (Figure 3; Table 2). Prey species were visually identified from photo graphs, video, or samples of remains collected near the surface with a dip-net after the feed ing event. ...
Citations
... Sand lance are known to comprise part of the diet for at least 100 predators Penttila, 2007;Harvey et al., 2010;Alheit and Peck, 2019;Staudinger, 2020;Scordino et al., 2022;Shaffer et al., 2023). Examples include seabirds, especially Alcids Zamon, 2000;Pastran et al., 2021); fish such as Chinook (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch; Duguid, 2020), Pacific cod (Gadus macrocephalus; Gunther et al., 2023), and lingcod (Ophiodon elongatus; Beaudreau and Essington, 2007); and larger mammals like Steller sea lions (Eumetopias jubatus; McKenzie and Wynne, 2008), harbor seals (Phoca vitulina richardii; Lance et al., 2012), and baleen whales such as humpback (Megaptera novaeangliae; Wright et al., 2016), minke (Balaenoptera acutorostrata; Okamura et al., 2009;Towers et al., 2019) and fin (Balaenoptera physalus; Moore et al., 2019). They play a particularly important role during the breeding of seabirds because of the high energy content, and slender bodies that are easily transported to, and consumed by, chicks (Willson et al., 1999;Bertram et al., 2001;Hedd et al., 2006;Beaubier and Hipfner, 2013). ...
Like many forage fish species, Pacific sand lance (Ammodytes personatus) play a key role in nearshore marine ecosystems as an important prey source for a diverse array of predators in the northeastern Pacific. However, the primary threats to Pacific sand lance and their habitat are poorly defined due to a lack of systematic data. Crucial information needed to assess their population status is also lacking including basic knowledge of their local and regional abundance and distribution. Sand lance are currently listed as ‘not evaluated’ under the IUCN red list and they have not been assessed by US and Canadian agencies. This hampers management and policy efforts focused on their conservation. To address this knowledge gap, we conducted a three-part, structured expert elicitation to assess the vulnerability of Salish Sea sand lance populations. Experts were asked to list and rank key threats to Salish Sea sand lance and/or their habitat, to further quantify the vulnerability of sand lance to identified threats using a vulnerability matrix, and to predict the population trajectory in 25 years from today. Impacts associated with climate change (e.g. sea level rise, sea temperature rise, ocean acidification, and extreme weather) consistently ranked high as threats of concern in the ranking exercise and quantified vulnerability scores. Nearly every expert predicted the population will have declined from current levels in 25 years. These results suggest sand lance face numerous threats and may be in decline under current conditions. This research provides vital information about which threats pose the greatest risk to the long-term health of sand lance populations and their habitat. Managers can use this information to prioritize which threats to address. Future research to reliably quantify population size, better understand the roles of natural and anthropogenic impacts, and to identify the most cost-effective actions to mitigate multiple threats, is recommended.
The minke whale (Balaenoptera acutorostrata) is a small species of baleen whale with a cosmopolitan distribution. Despite extensive study on the vocalizations of other balaenopterids, the acoustic repertoire of minke whales is not well known. Individuals of the North Pacific subspecies (B. acutorostrata scammoni) produce unique vocalizations (‘boings’) during their putative breeding season from fall to spring. However, no vocalizations have been previously reported for this subspecies in any eastern North Pacific feeding ground. We present two call types recorded in the presence of six minke whales, two of which were confirmed as female, in Cormorant Channel, British Columbia, Canada, during the summer of 2012. The calls consist of downsweeps and pulse chains. These call types share some characteristics with calls described elsewhere, although they are not identical to similar call types observed for other populations. Calling rates for minke whales in this study region are very low compared to those reported for this subspecies on its putative breeding grounds, as well as for other subspecies on their feeding grounds. We propose predation risk, sexual segregation and acoustic masking as potential causes of the low calling rates observed for minke whales in Cormorant Channel.
The minke whale (Balaenoptera acutorostrata) is the smallest species of baleen whale and has a cosmopolitan distribution. Despite extensive study on the vocalizations of other balaenopterids, the acoustic repertoire of minke whales is not well known. Individuals of the North Pacific subspecies of common minke whale (B. a. scammoni) are known to produce unique vocalizations ("boings") during their putative breeding season from fall to spring. However, no vocalizations have been previously reported for this subspecies in summer feeding grounds. We present four novel call types recorded in the presence of minke whales in Cormorant Channel, in coastal British Columbia, Canada, during the summer of 2012. These calls consist of broadband pulses, tonal wavers, downsweeps, and pulse trains. Calling rates for minke whales in this study region were very low compared to those reported for North Atlantic minke whales on their feeding grounds. We compare our candidate call types with vocalizations described for other minke whale populations and propose predation risk as a cause of the low calling rates observed for minke whales in Cormorant Channel.
