Blue Whale Vocalizations off the Scotian Shelf: Analysis and Management Implications

Transcription

1 Blue Whale Vocalizations off the Scotian Shelf: Analysis and Management Implications by Bette Rubin Dr. Hilary Moors- Murphy, Advisor/Client Dr. Andrew J. Read, Primary Advisor Dr. Douglas P. Nowacek, Secondary Advisor April 29, 2016 Masters project submitted in partial fulfillment of the requirements for the Master of Environmental Management degree in the Nicholas School of the Environment of Duke University

2 EXECUTIVE SUMMARY The blue whale (Balaenoptera musculus) is found in every ocean and is the largest animal to have ever lived on earth. The Atlantic population of blue whales is listed as Endangered under Canada s Species at Risk Act, which requires the Department of Fisheries and Oceans (DFO) to outline measures to help the species recover. DFO is investigating how and when blue whales use the Scotian Shelf, and is identifying research and data gaps in order to determine whether or not the area could be important habitat for blue whales. My work focused on passive acoustic monitoring (PAM) data, specifically data collected at three points along the Scotian Shelf over a period of two years. The overall goal of the project is to better understand how and when blue whales use the area, and identify research and data gaps for future study, so that eventually DFO may have enough information to identify and designate critical habitat for blue whales. My objectives were to look for interannual, seasonal, diel, and spatial trends in blue whale vocalizations, and in general, to consider the effectiveness of PAM as a means of identifying important blue whale habitat. Blue whales in the North Atlantic typically produce two types of sounds. The first is the tonal, or AB call, a combination of two parts, A and B. Tonal calls have been detected only from male blue whales, and they can occur sporadically or in stereotyped patterns, with distinct repetition of the AB call, or only one part of the call, at regular intervals. The second type of sound is known as the D call or the arch call. The arch call is believed to be used as a contact call or as a vocalization related to foraging. Autonomous Multichannel Acoustic Recorders (AMARs, JASCO Applied Sciences) were deployed by DFO at three locations along the slope of the eastern Scotian Shelf: one in the middle of the Gully (MidGul), another halfway between the Gully and Shortland Canyon (GulSho), and the third halfway between Shortland and Haldimand Canyons (ShoHald). Two years of recordings were collected, with AMARs being retrieved and deployed approximately every six months from October 2012 through September The files were run through automated blue whale tonal and arch call detectors developed by JASCO Applied Sciences. I personally validated 1,916 files, or approximately 530 hours of recordings. For the first 1.5 years of the study, the site with the most hours of detected blue whale vocalizations was ShoHald. However, in the second summer deployment, the proportion of hours with calls detected at MidGul was almost twice that of ShoHald. There were almost twice as many hours with blue whale vocalizations in Year 2 than in Year 1 (n=1584 and n=862, respectively). There is a clear trend in seasonality of call detections, with the majority of calls occurring during the winter months in both years of the study. Arch calls at MidGul were significantly more frequent at dusk hours than any other time of day (p < 0.001). Arch calls were found on less than 30 MidGul files from the beginning of deployment (September 2012) until the end of the third deployment (ending April 2014). However, in the second summer the fourth deployment MidGul files with arch calls comprised almost 93% of files with blue whale calls. The results of this study suggest that blue whales are around this part of the Scotian Shelf regularly, but there is variation. The peak in calls during the winter months was previously unknown, and thus provides a large contribution to future management decisions regarding species occurrence in this area. ii

3 Seismic surveys were conducted during the second summer of the study, the same season which showed an unpredicted increase in blue whale calls, within 100km of the Gully. Blue whales have been shown to increase their vocal behavior as a response to seismic airgun noise. The significant increase in blue whale calls during the second year of study might be able to help with future oil and gas survey regulations. Future effort should be spent in Shortland and Haldimand canyons, using PAM as well as visual surveys to explore cetacean abundance in these areas. Effort should be year- round, since evidence from the current study suggests blue whales might be present in this area even during winter months. Additionally, further study on the effects of anthropogenic noise on marine mammals is crucial and can play a significant role in determining critical habitat. iii

4 CONTENTS Executive Summary... ii Introduction... 1 Blue Whales... 3 Biology... 3 Threats... 3 Status... 4 Policy and Legal Framework... 5 Marine Mammal Regulations of the Fisheries Act... 5 COSEWIC... 5 SARA... 6 Gully Marine Protected Area Regulations of the Oceans Act... 8 Acoustics... 9 Blue Whale Bioacoustics... 9 Passive Acoustic Monitoring The Study Area Methods AMAR Deployments Automated Detections Manual Validation Examination of Vocal Occurrence Over Time Results Discussion Management Implications Things to Note Future Recommendations Acknowledgements References Appendix Images of AMARs and Mooring Setup iv

5 INTRODUCTION This Master s Project represents one piece of a much larger research program. I worked with Dr. Hilary Moors- Murphy of the Department of Fisheries and Oceans Canada (DFO), and her team of assistants and colleagues who were tasked with coordinating the compilation of information available on occurrence of blue whales in the Northwest Atlantic. Blue whales are listed as Endangered under the Canadian Species at Risk Act (SARA), and thus DFO is required to produce a SARA Recovery Strategy and Action Plan that outline the measures needed to help the species recover. One of the factors considered in the Recovery Strategy is critical habitat. On Canada s Atlantic coast, most studies on blue whales have occurred in the Gulf of St. Lawrence (Beauchamp, Bouchard, de Margerie, Otis, & Savaria, 2009), however data on blue whales has also been collected during cetacean research efforts focused on other species throughout the Scotian and Newfoundland Shelves (Figure 1). Data gathered from visual surveys, passive acoustic monitoring, and species distribution modeling, has formed a more comprehensive understanding of the presence of blue whales outside of the Gulf of St. Lawrence (Moors- Murphy et al., 2016). Despite these efforts, critical habitat has yet to be determined and designated for the Atlantic population of blue whales in Canada. My work focused on the passive acoustic monitoring (PAM) data, specifically data collected at three points along the Scotian Shelf over a period of two years. The overall goal of the project is to better understand how and when blue whales use the area, and identify research and data gaps for future study, so that eventually DFO may have enough information to identify and designate critical habitat for blue whales. My objectives were to look for interannual, seasonal, diel, and spatial trends in blue whale vocalizations, and in general, to consider the effectiveness of PAM as a means of identifying important blue whale habitat. Figure 1. Map of the continental shelf off the Northeast coast of North America. Boxes indicate the Gulf of St. Lawrence, the Scotian Shelf, and the Grand Banks and Newfoundland Shelf, as labeled. Map courtesy of Google maps. 1

6 Specifically, I wanted to determine whether or not a pattern exists in the timing of blue whale calls. Blue whales have been visually observed in the study area during the summer months (Whitehead 2013), but little is known beyond that. Acoustic detection of blue whales has never been conducted in the study area before, and visual observations have never been conducted in the winter months. Thus, understanding what, if any, trends exist in blue whale call behavior, could offer new insight to the spatial and temporal use of this area by blue whales. While one previous study found that blue whale vocalizations in the North Atlantic (near the Mid- Atlantic Ridge) were most abundant during the winter months (Nieukirk, Stafford, Mellinger, Dziak, & Fox, 2004), Dr. Moors- Murphy and her team thought that there would be more vocalizations during the summer months, since from , her team deployed four Marine Autonomous Recording Units (MARUs) in the same area as this study, and found that more than three times as many blue whale calls were detected in the summer and early fall than in the winter (Moors- Murphy et al., 2016). I wanted to know if blue whale calls were detected year- round, and if the trends were consistent across years. Furthermore, I wondered if blue whale calls would be more prevalent at one recorder location than another, and if so, what the cause might be of the discrepancy since the recorders are all within 100 kilometers of each other. Within blue whale calling behavior, I wanted to investigate whether a particular call type is more frequently observed than another. Blue whales in the North Atlantic typically exhibit two types of calls, and it is thought that these calls are used for different purposes. Knowing temporal patterns in call types could provide useful information about how and when blue whales use the area. I also wondered if there was any diel pattern to blue whale calls, which might offer more information on the purpose of those calls. Finally, I wanted to know if any significant events (severe weather, changes in physical oceanographic variables, human activity, etc.) occurred during the study period which might aid in understanding what trends (if any) emerged. Figure 2. Dorsal side of a blue whale. Note the blowholes, left, and the mottled coloring throughout. This unique pattern is what gives the species its common name, and is also how individual whales are identified. Photo courtesy of Mingan Island Cetacean Study (MICS). 2

7 Blue Whales Biology Blue whales (Balaenoptera musculus) are the largest animal to have ever lived on earth, and are found in every ocean except the Arctic. They are sexually dimorphic, with adult females reaching lengths of up to 33 meters and adult males averaging 29 meters, according to Rice, 1978 (as cited in Sears & Calambokidis, 2002). Blue whales are identified by their large size and grey- blue mottled color (Figure 2), which gives the species its common name. The mottled pattern is also how individuals are identified. Blue whales are part of the taxonomic family Balaenopteridae, or rorquals, characterized by ventral throat grooves which distend enormously during feeding. Like all baleen whales, rorquals have hundreds of keratinized baleen plates which they use to capture prey while expelling water with their tongues. Blue whales feed primarily on euphausiids, tiny shrimp- like zooplankton, commonly known as krill. To make the energy expenditure of foraging worthwhile, blue whales target dense patches of prey, which they engulf in a single gulp. Blue whales may consume up to 4 tons of krill each day (Sears & Calambokidis, 2002). Euphausiids are known to exhibit vertical diel migrations: they sink to lower depths during the day, and rise toward the surface at night (Oleson et al., 2007b). Ironically, despite being the largest animal on the planet, very little is known about blue whale migration, reproduction, and other behavioral patterns. Studies have shown that blue whales migrate seasonally, but are detected acoustically year- round in certain areas, indicating that at least some do not migrate (Burtenshaw et al., 2004; Oleson et al., 2007b; Stafford, Moore, & Fox, 2005; Stafford, Nieukirk, & Fox, 2001). Threats The endangered status of blue whales is a consequence of past commercial whaling activities, from which the species has not yet recovered. According to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), threats to the population of blue whales in eastern Canada include predation, ice entrapment, historic whaling, anthropogenic noise, food availability, pollution, ship strikes, whale watching, entanglement in fishing gear, toxic algal blooms and other disease, and toxic spills (COSEWIC, 2012). Globally, between 10,000 and 25,000 blue whales remain after the species was decimated by commercial whaling in the past century (Reilly, et al., 2008). Commercial whaling is thought to 3

8 have reduced abundance of the species by roughly 70% (Beauchamp et al., 2009). There are an estimated 3,000-4,000 individual blue whales in the northern hemisphere, and while it is currently unknown how many blue whales use the waters off eastern Canada (Sears & Calambokidis, 2002), it is thought that there are not more than 250 mature blue whales in the Northwest Atlantic (Beauchamp et al., 2009). Most of the data collected on blue whales in the North Atlantic has focused on the Gulf of St. Lawrence and the St. Lawrence Estuary, where blue whales are known to occur in the summer. However, again the data collection is biased toward the summer months, and thus there are large gaps in the knowledge of blue whale occurrence outside the summer season. Natural threats to blue whales are not well understood. The only known predator of the blue whale is the killer whale or orca (Orcinus orca), but there is no information on how often predation occurs with this population of blue whales (Beauchamp et al., 2009). It is possible that ice entrapment poses a population- level threat, but there is insufficient data to determine this with certainty (Moors- Murphy et al., 2016). A total of 51 animals were involved in ice entrapment incidents from 1974 to 2015 (Moors- Murphy et al., 2016). These primarily occurred in March and April each year, and 78% of the entrapped animals died (Moors- Murphy et al., 2016). These numbers only reflect the known incidents, and the number of whales actually entrapped by ice is likely higher (Moors- Murphy et al., 2016). The most important threats to blue whales arise from human activities. Vessel collisions are arguably the primary threat to blue whales today. However, threats which have the potential to alter blue whale behavior over time also pose significant risk to the species. Seismic testing, oil and gas development, shipping traffic, military activities, and other forms of resource use and extraction in the ocean has added significant levels of noise to the underwater environment. In Canadian waters, the shipping and oil and gas industries are responsible for the most noise pollution (Beauchamp et al., 2009). This noise pollution, which does not necessarily cause immediate injury or fatality, but rather is constant and can cause indirect injury over long periods of time, is a chronic threat. Status As a result of its depleted status, the species is protected by many international treaties and national laws and regulations. Blue whales are considered Endangered by the International Union for the Conservation of Nature s (IUCN) Red List of Threatened Species, the primary 4

9 international conservation authority. They are also listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which prohibits international trade in endangered species (CITES). Blue whales are also protected from commercial harvest worldwide by the International Whaling Commission (IWC). In the United States, blue whales are considered Depleted under the Marine Mammal Protection Act and Endangered under the Endangered Species Act. In Canada, blue whales are assessed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and listed as Endangered under the Species at Risk Act (SARA), and are also protected under the Marine Mammal Regulations of the Fisheries Act (Marine Mammal Regulations, SOR/93-56). Policy and Legal Framework Marine Mammal Regulations of the Fisheries Act The Marine Mammal Regulations were first passed in 1993, under the Fisheries Act (Fisheries Act, RSC, 1985, c F- 14). The regulations prohibit certain activities regarding marine mammals, such as disturbing, killing, marking or tagging (unless granted a special license to do so), buying, selling, or trading any or all parts of a cetacean (Marine Mammal Regulations, SOR/93-56, s 13). However, they also have some provisions for licensed seal hunts, as well as for aboriginal peoples to hunt and kill marine mammals for subsistence purposes (Marine Mammal Regulations, SOR/93-56, s 7-10). The regulations allow the killing of certain marine mammal species, but not blue whales. These regulations simply serve as a further layer of federal protection for blue whales. COSEWIC The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is responsible for publishing working documents assessing the status of species that might be at risk. It provides its own status designation for species it reviews. COSEWIC was created in 1977, and with the passage of SARA, it became an official advisory body. This means that the government of Canada will take COSEWIC s designations into consideration when establishing the legal list of wildlife species at risk (COSEWIC, 2002). SARA mandates that COSEWIC conduct a review on the status of a species at risk every 10 years, and that a Minister (the Minister for the Parks Canada Agency for species occurring in or on federal lands; the Minister of Fisheries and Oceans for aquatic species; and the Minister of the Environment for all other species) must respond to a COSEWIC status assessment 5

10 within 90 days of receiving the assessment. This response must be included in the public registry, and must include the minister s plans for action. In 2002, COSEWIC published an Assessment and Update Status Report on the Blue Whale. This Report provided species information for both the Atlantic and Pacific populations of blue whales in Canada, and designated both populations as Endangered. In 2012, COSEWIC released a Status Appraisal Summary on the Blue Whale Atlantic population in Canada. The 2012 report essentially confirmed the 2002 findings, maintaining COSEWIC s Endangered status designation and suggesting that DFO maintain its Endangered status for blue whales in Atlantic Canada. SARA The Species at Risk Act received Royal Assent in December of 2002, and the law came into effect in The preamble to SARA recognizes that wildlife has inherent value, and that Canada has obligations to protect species at risk due in part to Canada s ratification of the United Nations Convention on the Conservation of Biological Diversity. The preamble states that the precautionary principle should be used to avoid the complete loss of any at- risk species. Furthermore, SARA recognizes the importance of traditional knowledge of the aboriginal peoples of Canada, as well as the importance of habitat to ensuring species conservation (Species at Risk Act, SC 2002, c 29, Preamble). SARA states that no person shall kill, harm, harass, capture or take an individual of a wildlife species that is listed as an extirpated species, an endangered species or a threatened species (Species at Risk Act, SC 2002, c 29, s 32). The text expands on this to include the possession, sale or trade of an endangered or threatened species, or any part of an endangered or threatened species. Furthermore, the law states that no person shall damage or destroy the residence of one or more individuals of a wildlife species that is listed as an endangered species or a threatened species (Species at Risk Act, SC 2002, c 29, s 33). Since residence is difficult to define with highly migratory species such as the blue whale, it is helpful to think of residence in this section as referring to critical habitat. There was precedent for listing blue whales under SARA. Both the Atlantic and Pacific populations of blue whales were designated under earlier laws as a species of Special Concern in The two populations Atlantic and Pacific were separated in 2002, and in 2005, the Northwest Atlantic 6

11 population of blue whales was listed as Endangered under SARA. After an aquatic species has been listed under SARA, DFO is tasked with compiling all relevant and useful data to determine next steps in the recovery and management process. Recovery Strategy Under SARA, if a wildlife species is listed as an endangered species the competent minister must prepare a strategy for its recovery (Species at Risk Act, SC 2002, c 29, s 37). Under this section, again the law discusses the precautionary principle: the competent minister must consider the commitment of the Government of Canada to conserving biological diversity and to the principle that, if there are threats of serious or irreversible damage to the listed wildlife species, cost- effective measures to prevent the reduction or loss of the species should not be postponed for lack of full scientific certainty (Species at Risk Act, SC 2002, c 29, s 38) (emphasis added). The recovery strategy must include a description of the species, its population size and distribution, the threats to its survival, the habitat the species occupies, and what research and management steps need to occur to assist the recovery and survival of the species (Species at Risk Act, SC 2002, c 29, s 41). The Recovery Strategy for the Blue Whale, Northwest Atlantic Population, in Canada, was published in The recovery strategy did not identify Critical Habitat, citing lack of best available information as the cause. It did suggest that future research into Critical Habitat would consider functional ecological units in order to ensure feeding and reproductive success (Beauchamp et al., 2009). Furthermore, it outlined a Schedule of Studies to be conducted in order to acquire the necessary data to discuss Critical Habitat. Action Plan Following the publication of a Recovery Strategy, SARA requires the competent Minister to prepare an Action Plan. The Action Plan must identify the species Critical Habitat, including proposed measures to protect the Critical Habitat and further implement the Recovery Strategy (Species at Risk Act, SC 2002, c 29, s 49). While the Recovery Strategy for the Northwest Atlantic population of blue whales stated that an Action Plan would be developed by 2014, it does not yet exist. However, DFO is working to provide the best available information to protect the blue whale population. 7

12 Critical Habitat Critical habitat is defined in SARA as: the habitat that is necessary for the survival or recovery of a listed wildlife species and that is identified as the species critical habitat in the recovery strategy or in an action plan for the species (Species at Risk Act, SC 2002, c 29, s 2). Once established, SARA prohibits the destruction of any part of the critical habitat for aquatic species (Species at Risk Act, SC 2002, c 29, s 58). Figure 3. The Gully Marine Protected Area, with its three zones of varying levels of protection and restrictions. Figure courtesy of DFO. Gully Marine Protected Area Regulations of the Oceans Act Research in the Gully began in the 1970s and 1980s to study northern bottlenose whales (Department of Fisheries and Oceans Canada [DFO], 2008). This research increased interest in the Gully and its conservation, and in 1994 DFO designated the Gully as a Whale Sanctuary (DFO, 2008). Conservation interests increased over time, and research continued on ways to protect the Gully, it was designated as a Marine Protected Area (DFO, 2008). The Gully was designated in 2004 as regulations under the Oceans Act (Oceans Act, SC 1996, c 31). The Gully MPA consists of three zones (Figure 3), and prohibits disturbing, damaging, destroying, or removing any living marine organism or any part of its habitat any part of the seabed, including the subsoil, or depositing, 8

13 discharging or dumping any substance, or causing any substance to be deposited, discharged or dumped in the Gully MPA or close enough to the Gully that it might harm the species and habitats therein (Gully Marine Protected Area Regulations, SOR/ , s 4). Exceptions to the prohibited activities include military or other security- related exercises, fishing with proper licenses, or other activities approved by the appropriate minister. One of the high priorities in terms of management of the MPA is monitoring the year- round presence of cetacean species. Acoustics Blue Whale Bioacoustics Blue whales are the loudest mammals on earth; their calls are often thought to reach across entire ocean basins (McKenna, 2013). Their calls are infrasonic at a frequency just at, or slightly below, the range of human hearing (20 Hz). This makes it difficult to detect blue whale calls without the aid of special technology that can amplify and speed up the calls. While it is unknown how or why these whales evolved to call at such low frequencies, many scientists agree that it might have been an adaptation to accommodate such large animals wanting to communicate across great distances in the water, as their calls are at ideal frequencies for long- distance underwater communication (Clark & Ellison, 2004). It is plausible that the largest animal on earth would want to communicate across an ocean basin, and thus would have adapted to accomplish this feat without suffering significant energetic costs. Furthermore, in high latitudes, where intensive feeding occurs during summer months, surface ducting confines the sound channel to the upper 100 m layer, an environmental feature that also facilitates long- range communication (Clark & Ellison, 2004). Indeed, blue whales are known to occur in high latitudes during summer months to engage in intensive feeding. Blue whales in the North Atlantic typically produce two types of sounds. The first is the tonal, or AB call, a combination of two parts, A and B. Part A is around 5-8 seconds long, and remains for the most part on a single frequency (Mellinger & Clark, 2003). In Northwest Atlantic blue whales, this frequency is between 18 and 20 Hz (Mellinger & Clark, 2003). Part B starts around the same frequency as part A, and includes a slight down- sweep (frequency modulation), ending at around 16 Hz (Mellinger & Clark, 2003). Part B is shorter in duration than part A. These two call components can occur on their own (A- only or B- only), which lasts 8-10 seconds, or they can occur together (the AB call), making a call that lasts seconds (Mellinger & Clark, 2003). Tonal calls have been detected only from male blue whales, and they can occur sporadically or in stereotyped 9

14 patterns, with distinct repetition of the AB call, or only one part of the call, at regular intervals. When calls are stereotypic and repetitive (lasting hours, or even days), they are referred to as song (McDonald, Mesnick, & Hildebrand, 2006). Songs are believed to be produced only by males, and are thought to function as a type of mating call, similar to the songs of other large whale species (Oleson et al., 2007b). The second type of sound is known as the D call or the arch call. The arch call is higher in frequency than tonal calls, and is another type of frequency- modulated down- sweep. Arch calls start at around 50 Hz, sweep up to around 70 Hz, and then sweep down to around 30 Hz (Mellinger & Clark, 2003). These calls are 2-6 seconds long and do not occur as often as the tonal calls. Arch calls are higher in frequency than the tonal calls, but they can still be difficult for the human ear to detect. Both males and females make arch calls (Oleson et al., 2007a). All blue whale calls, including both tonal and arch calls, are best heard by human analysts when sped up and amplified, due to their low frequencies. Some studies have suggested that the arch call, at least for blue whales in the Pacific ocean, is used as a contact call a communication to nearby conspecifics (McDonald, Calambokidis, Teranishi, & Hildebrand, 2001; Melcon et al., 2012; Oleson et al., 2007b; Wiggins, Oleson, McDonald, & Hildebrand, 2005). Furthermore, it is believed that the arch calls may be related to foraging (Oleson et al., 2007a) whether to inform other conspecifics where large prey aggregations are or to maintain contact with a large group of conspecifics (Melcon et al., 2012). Additionally, it has been proposed that these calls are related to the diel vertical migration of the prey (Oleson et al., 2007b). Passive Acoustic Monitoring Passive acoustic monitoring, or PAM, offers numerous advantages for studying marine mammals over more traditional visual methods. Visual surveys rely on human effort, favorable weather and water conditions, daylight, and have a relatively limited detection range. Acoustic monitoring provides an alternative to these barriers: PAM does not require daylight hours, does not rely on favorable weather conditions, and has a much larger detection range (Wiggins, 2003). While PAM does have its limitations, it also has proven to be of incredible value to researchers, who have been able to provide new information on the seasonal presence, abundance, call character, and patterns of vocalizing whales (Wiggins, 2003). Furthermore, PAM is less intrusive and reduces the risk of interfering with normal whale behavior (McDonald, Hildebrand, & Webb, 1995). 10

15 The Study Area The Scotian Shelf extends approximately 200 kilometers off the coast of Nova Scotia (Figure 1). The slope area of the shelf break has several submarine canyons, the biggest of which is the Gully. The continental shelf break and surrounding slope area has long been recognized as an area of high cetacean density. Along the shelf break, just east of Sable Island, lies the Gully, the largest submarine canyon off the east coast of North America (Figure 4) (Whitehead, 2013). The Gully was the second Marine Protected Area (MPA) to be established in Canada and the first MPA in Atlantic Canada. It is a well- studied site, known for its diversity of marine wildlife and geographic features. The Gully is approximately 40 kilometers long, 16 kilometers wide, and at its deepest depth, reaches more than 3 kilometers deep (DFO, 2008) (Figure 3). Cetaceans have been studied in the Gully since the late 1980s, and this research has underscored the notion that the Gully is an important area for cetaceans and other forms of marine life (Hooker, Whitehead, & Gowans, 1999; Whitehead, 2013). Figure 4. The Scotian Shelf and other relevant landmarks around the Gully MPA. Figure courtesy of DFO. The two submarine canyons directly east of the Gully along the shelf break are, respectively, Shortland and Haldimand (Figure 5). These canyons are, like their neighbor, the Gully, full of biodiversity, including many different cetacean species (Whitehead, 2013). Neither Shortland nor Haldimand canyon are currently protected by any legal framework in Canada (Whitehead, 2013), though they have been designated as Critical Habitat for northern bottlenose whales (DFO, 2010a), and thus will be protected under the SARA in the future (H. Moors- Murphy, pers. comm.). 11

16 The Scotian Shelf has been extensively studied with regard to other marine mammal species, allowing for data on blue whales to be collected during cetacean research efforts focused on other species. The Gully, Shortland Canyon and Haldimand Canyon are, as mentioned above, designated Critical Habitat for the northern bottlenose whale (Hyperoodon ampullatus), and the Recovery Strategy for the species recommended future studies to identify additional critical habitat, specifically acoustic and visual monitoring of shelf break between the Gully, Shortland Canyon, and Haldimand Canyon, to identify routes used by whales moving between canyons and evaluate the importance of specific corridors (DFO, 2010a). Dr. Moors- Murphy and her team were deploying recorders for that purpose, but also collected data to monitor the occurrence of other whale species. They used this opportunity to listen for blue whales, as well as many other cetacean species, on the recordings collected. This also accomplished a recommendation regarding the conservation objectives of the Gully MPA, which recommends monitoring, through other existing deployments and research opportunities, the relative abundances of cetaceans (other than northern bottlenose whales) in the Gully MPA, and cetacean presence and activity in the MPA, year- round (DFO, 2010b). Figure 5. Submarine canyons along the Scotian Shelf, including the Gully, Shortland, and Haldimand canyons, which were the focus of this study. Figure courtesy of DFO. A 2013 study examined cetacean density in the Gully and Shortland and Haldimand Canyons, and reported that more blue whales were seen in the Gully compared to the other two canyons 12

17 combined (n=33 vs. n=14, respectively), but when adjusted for effort (hours spent in each location), the rate of sightings per unit effort was higher for the two other canyons than for the Gully ( versus whales sighted per hour, respectively) (Whitehead, 2013). While these data suggest that there are more whales present in Shortland and Haldimand canyons, it is important to note that the difference in sighting rate was not found to be statistically significant. However, the author did note in his discussion that the fact that the rates were not significantly different when comparing the Gully to the other two canyons is important. He argued that since the rates were similar across the sites, this might imply that protection provided by the Gully MPA has not yet made a large difference to the abundances of the species considered although the time span since designation may be too short for the effectiveness of the MPA to fully emerge (Whitehead, 2013). METHODS In February 2016, a team of DFO scientists met in Vancouver for a National Marine Mammal Peer Review Committee. The first topic on the agenda for this meeting was to discuss habitat requirements for the Atlantic population of blue whales, as well as habitat requirements for two other marine mammal species. Dr. Moors- Murphy submitted a research document at this meeting, compiling the information currently available for blue whales in waters off Nova Scotia, Newfoundland and Labrador. This report is part of the Canadian Science Advisory Secretariat (CSAS) process for reviewing habitat requirements for the Northwest Atlantic population. The CSAS is responsible for coordinating the production of peer reviewed science advice for DFO (DFO, CSAS). The research document will be available to SARA managers at DFO, who will review it and determine which areas off eastern Canada should be legally designated as critical habitat for blue whales (H. Moors- Murphy, pers. comm.). AMAR Deployments Autonomous Multichannel Acoustic Recorders (AMARs, JASCO Applied Sciences, see Appendix) were deployed by DFO at three locations along the slope of the eastern Scotian Shelf: one in the middle of the Gully (MidGul), another halfway between the Gully and Shortland Canyon (GulSho), and the third halfway between Shortland and Haldimand Canyons (ShoHald) (Figure 6). Again, these locations were chosen due to the research goals of the northern bottlenose whale recovery strategy. All AMARs were moored between 1,370 and 1,850 meters depth, with each instrument suspended approximately 60 meters off the bottom. The AMARs house M8 omnidirectional 13

18 hydrophones developed by Geospectrum Technologies Inc. and are capable of continuous recording for approximately 100 days before needing batteries and memory to be replaced (JASCO Applied Sciences, 2012). The AMARs have a broadband noise floor of 63 db re 1 µpa and a broadband dynamic range of 104 db (Moors- Murphy et al., 2016), and uses a 24- bit analog- to- digital converter, as well as a built- in anti- aliasing filter (JASCO Applied Sciences, 2012). Figure 6. Map of the three canyons of interest for this study, along with locations of each AMAR deployed. Inset: the Scotian Shelf. Pink box indicates area of enlarged map. Figure courtesy of Hilary Moors- Murphy. Two years of recordings were collected, with AMARs being retrieved and deployed approximately every six months from October 2012 through September 2014 (Table 1). October 2013 was the only month during this two- year period from which no data was collected. The equipment collected data continuously, sampling at a rate of 16 khz for 13 minutes then at 128 khz for 2 minutes during the first year of the study, and 16 khz for 17.8 minutes and 250 khz for 2.2 minutes during the second year. The high frequency data was used for the northern bottlenose whale study and to examine the occurrence of other toothed whales, and were not used for this analysis. 14

19 Therefore, for purposes of this study, the acoustic files were recorded on a duty cycle of 13 out of 15 minutes, or 86.67%, for the first year, and 17.8 out of 20 minutes, or 85%, for the second year. Table 1. Description of AMAR deployments included in the blue whale analysis. LF = 16 khz sampling rate; HF = 128/250 khz sampling rate. Table taken from Moors- Murphy et al., Location Deployment Recorder Depth Date of First Recording Date of Last Recording MIDGUL Fall/Winter 1, Oct Apr 2013 MIDGUL Spring/ Summer 1,520 7 May Sep 2013 MIDGUL Fall/Winter 1, Nov Apr 2014 MIDGUL Spring/ Summer 1,470 3 May Sep 2014 GULSHO Fall/Winter 1, Oct Apr 2013 GULSHO Spring/ Summer 1,520 8 May Sep 2013 GULSHO Fall/Winter 1, Nov Apr 2014 GULSHO Spring/ Summer 1,560 3 May Sep 2014 SHOHALD Fall/Winter 1, Oct Apr 2013 SHOHALD Spring/ Summer 1,490 8 May Sep 2013 SHOHALD Fall/Winter 1, Nov Apr 2014 SHOHALD Spring/ Summer 1,500 3 May Sep 2014 Duty Cycle 13 min LF/ 2 min HF 13 min LF/ 2 min HF 17.8 min LF/ 2.2 min HF 17.8 min LF/ 2.2 min HF 13 min LF/ 2 min HF 13 min LF/ 2 min HF 17.8 min LF/ 2.2 min HF 17.8 min LF/ 2.2 min HF 13 min LF/ 2 min HF 13 min LF/ 2 min HF 17.8 min LF/ 2.2 min HF 17.8 min LF/ 2.2 min HF Number of Recordings 17,262 13,553 10,228 10,603 17,271 13,564 10,233 10,573 17,273 13,606 10,295 10,529 All 154,990 Automated Detections The files were run through automated blue whale tonal and arch call detectors developed by JASCO Applied Sciences. The detectors were designed to minimize the chance of missing even a quiet blue whale call, which yielded a high false positive rate. The detectors identified 15,077 files with potential blue whale vocalizations (n=38,394 individual detections on 154,990 files). I then manually validated the files identified by the detectors as containing blue whale calls. 15

20 Manual Validation I personally validated 1,916 files, or approximately 530 hours of recordings. These were files that the JASCO detectors determined to contain blue whale calls, and came from all deployments at all three sites of the study. Manual validation involved reading the spectrogram of each file to visually and aurally confirm the presence of a blue whale vocalization, regardless of whether it was a tonal or arch call. The analysis was executed using a presence- absence method. Any files where blue whale vocalizations were confirmed to be present were given a value of 1, and files where no blue whale vocalizations were present were assigned a value of 0. I used Raven Pro 1.4 Interactive Sound Analysis Software, developed by the Cornell Lab of Ornithology Bioacoustics Research Program, to validate the files. Using a Hanning window and 50% overlap, with FFT size = 65,536, I fit the window to show the frequency range of Hz, and visually scanned each file around Hz and Hz, for blue whale tonal and arch calls, respectively. Fin whales also produce calls around 20 Hz, which could make blue whale detection difficult, except that the types of calls are very different. Fin whale 20 Hz calls are short pulses, which, when using the spectrogram settings described above, look like vertical lines. Blue whale tonal calls on a spectrogram look like horizontal, slightly curved, lines (Figure 7). If it seemed that a blue whale call might be present, I selected the signal and amplified it, usually by a magnitude of 10. Additionally, I sped up the playback by 5 or 10 times. These two steps combined to make a louder, slightly higher- frequency sound that was audible to the human ear. By listening to the file or parts of it after initially visually scanning it, I could confirm or refute the presence of a blue whale call. Examination of Vocal Occurrence Over Time Once the validated data had been collected and tabulated, I conducted a thorough analysis to look for patterns in vocal occurrence. For this analysis, hourly call presence was examined. That is, rather than just looking at the number of 13 or 17.8 minute files with calls present, an analyst determined the number of hours in each day where at least one call was detected. This allowed for analysis of the number of hours in the day with confirmed blue whale calls present. It is important to note that blue whales do not always vocalize; therefore, periods of time where blue whales were not acoustically detected do not necessarily imply that blue whales were not present. This means that the data presented represent their minimum hourly presence within an area. 16

21 Figure 7. Spectrogram of blue whale tonal calls (surrounded by black box). Note the vertical green and yellow lines near the blue whale calls; these are fin whale calls. Spectrogram created using Raven 1.4 software. Hanning window and 50% overlap, with FFT size = 65,536. Spatial Variability Given the differences in the environment where the recorders were deployed, I was interested in seeing whether one location had more call detections than another. Specifically, whether the MidGul AMAR in the middle of a submarine canyon, as compared to the other two AMARs which were on the continental shelf slope, would have very different acoustic characteristics. I wondered if MidGul would have more calls detected, due to the sound propagation I expected to occur in a deep canyon, or if it would have fewer calls detected due to its having more bathymetric obstacles than the slope shelf, meaning higher transmission loss of the calls. In addition to the sound propagation questions, the potential spatial variability of blue whale calls could indicate habitat use or preferences. If the canyons provide higher concentrations of krill, then blue whales might prefer the canyon to the shelf slope, and thus might be more likely to occur within the canyons. Site selection preference in this area could provide valuable insight into blue whale habitat use, and could highlight certain areas (e.g., canyons) that are more important for the species than other areas (e.g., the shelf slope). 17

22 Interannual Variability The two years of data allowed me to compare vocalization between years. I wanted to see if there were similar patterns in detected calls for both years, or if each year was different. If the detected calls exhibited similar patterns both years, it might suggest an annual pattern that can be predicted and observed every year. However, if the two years of data did not show annual similarities, it might suggest that one year was anomalous, which would lead to inquiries on what happened in each year that might account for such differences. A study of blue whale calls in California detected one year of peak blue whale call detections out of a 7- year study period, but did not see any long- term patterns (Širović, Rice, Chou, Hildebrand, Wiggins, & Roch, 2015). This suggests that the variability between years cannot necessarily be considered either a pattern or an anomaly. Seasonal Variability Since prior studies (primarily visual surveys) were limited to summer months (e.g., Whitehead 2013), it was unknown whether there would be a pattern in seasonal call detections. Širović et al. (2015) found the majority of detected blue whale calls in the Southern California Bight occurred from June to January, with a peak in September (Širović et al., 2015). This would suggest that the summer and fall months would have the most blue whale call detections in my data set. Diel Variability As mentioned above, many scientists have hypothesized that blue whale arch calls may be related to the diel vertical migration of their prey, the euphausiids (Wiggins et al., 2005). Furthermore, there are a few instances in the scientific literature that document diel patterns in blue whale vocalizations (Wiggins et al., 2005), both the arch calls and the tonal calls (Oleson et al., 2007b). When analyzing blue whale calls in the eastern tropical Pacific, Stafford et al. (2005) found tonal calls were more prevalent during dusk and dark hours (Stafford et al., 2005). Oleson et al. (2007) found that arch calls were the most common call type during the day, but that both arch and tonal calls followed similar patterns from dusk to dawn. This led me to wonder if the blue whales off the Scotian Shelf also exhibit diel patterns in their vocalizations, either tonal or arch calls. Files were originally given timestamps in GMT, and adjustments were made during the analysis to account for the proper time zone in terms of daylight hours and daylight savings time. 18

23 Call Type Variability Examination of call variability is related to diel variability. Blue whales are thought to produce tonal calls when they are 10-40m under the surface of the water, due to physiological restraints (Wiggins et al., 2005), which would suggest that blue whales do not produce tonal calls while they are feeding, since these whales forage at greater depths than 40m (Oleson et al., 2007a). Wiggins et al. (2005) found that off the coast of California, blue whale tonal calls were greater at night than during the day, with peaks around dawn and dusk (Wiggins et al., 2005). Furthermore, Oleson et al. (2007a) observed arch calls solely during breaks from foraging at depth (Oleson et al., 2007a). I wanted to determine whether there were any patterns, diel or other, in the occurrence of arch calls versus tonal calls. This required a second round of analysis, since the original method of manual validation only accounted for presence and absence of any blue whale call. Analysts in Dr. Moors- Murphy s lab conducted this second analysis, reviewing each file of confirmed blue whale calls in more detail and noting whether tonal and/or arch calls were present. RESULTS The two years of deployment resulted in 154,990 low frequency files (or recordings) (4 files from each hour of deployment during the first year, and 3 files from each hour of deployment during the second year), or 37,743 hours of recordings (Table 1). Of the 15,077 files determined by the JASCO detectors to contain blue whale calls, 4,614 (30.6%), were confirmed to contain blue whale vocalizations. This validation exercise indicates that the JASCO detectors had a false positive rate of 69%. Other analysts working with Dr. Moors- Murphy determined the false negative rate to be 5.8% by examining files which had no blue whale detections on them for the presence of blue whale calls. The relatively- high false positive and low false negative rates normally would prove that the detectors were perhaps too sensitive or broad, including a lot of noise which fell within the expected frequency of blue whale calls, but which were not actually coming from blue whales. However, for the purposes of this study, the high false positive rate was intentional, because Dr. Moors- Murphy and the team at JASCO wanted to minimize the chance of missing a blue whale call. 19

24 Proportion of Hours with Confirmed Blue Whale Calls, by Deployment Proportion of Total Hours (%) Oct Apr 2013 May-Sept 2013 Nov Apr 2014 Deployment Dates May-Sept 2014 MidGul GulSho ShoHald Figure 8. Proportion of hours with confirmed blue whale calls per deployment, at each location. Spatial Variability Spatial patterns emerged during the analysis. For the first 1.5 years or 3 deployments of the study, the site with the most hours of detected blue whale vocalizations was ShoHald. However, for the last deployment, occurring in Summer 2014, more hours with vocalizations were detected in the MidGul location (Figure 8). Furthermore, looking at spatial variability by season, it seems as though ShoHald had the most files with blue whale calls in Fall, Winter and Spring, but the most files with blue whale calls in Summer came from MidGul (Figure 9). This is due to the second summer spike in calls at MidGul, as is evident from the fact that during the first summer, the most detections came from ShoHald. In the second summer deployment, the proportion of hours with calls detected at MidGul was almost twice that of ShoHald. Detections per Season, by AMAR Hours with blue whale detections Fall Winter Spring Summer Season MidGul GulSho ShoHald Figure 9. Spatial variability of blue whale calls during each season. 20

25 Interannual Variability There were almost twice as many hours with blue whale vocalizations in Year 2 than in Year 1 (n=1584 and n=862, respectively) (Figure 10). During Year 1, November, December, and January had seven times as many hours with vocalizations as the rest of the deployment. However, while this peak was seen in Year 2 as well, a second peak occurred in Year 2 in the summer, with July and August each having more hours of vocalizations than November or January (Table 2). More years of recording are needed to determine whether or not a pattern exists between years, or if one of these years was anomalous. Figure 10. Hours with detected blue whale calls for each month of the study. Colors represent the different locations. Gray bar over October of the second year indicates no data were collected. 21

26 Table 2. Number of hours with blue whale calls per month for both years of the study. Note that these values include data from all three locations. Month Total Hours with Blue Whale Detections, Year 1 Total Hours with Blue Whale Detections, Year 2 October 35 NA November December January February 7 55 March 0 46 April 1 0 May 1 23 June 1 60 July August September Total Seasonal Variability There is a clear trend in seasonality of call detections (Figure 11), with the majority of calls occurring during the winter months in both years of the study. However, again a summer peak can be observed during the second year. The first summer deployment is incredibly low, compared to the three other deployments, in terms of hours with confirmed blue whale calls. The first deployment, during the fall and winter months, shows the most hours with detected calls at ShoHald, followed by GulSho, with MidGul having the least amount of hours with calls. However, the proportion of hours with confirmed blue whale calls at MidGul quadrupled from the first to the third deployments, showing a bigger change than either of the other locations. The proportion of hours with calls at GulSho stayed relatively consistent between these two deployments (the first and third deployments both reflect the late fall and winter months), but decreased slightly in the third deployment, and there was an increase in the proportion of calls at ShoHald from the first deployment to the third. The cause of this variation is unknown at this time. 22

27 Hours with blue whale detections Seasonality of Detected Blue Whale Calls Fall Winter Spring Summer Season Year 1 Year 2 Figure 11. Number of hours with blue whale calls per year, per season. Diel Variability Calls were most prevalent during the evening hours. At MidGul and GulSho, Hours had the most files with detected calls, whereas the most detected files at ShoHald were Hours (Figure 12). With the available call type data for MidGul (see Call Variability results, below), I compared files with detected calls at four different times of day dawn, day, dusk, and night using a Kruskal- Wallis rank sum test. Arch calls at MidGul were significantly more frequent at dusk hours than any other time of day (p < 0.001) (Figure 13). Tonal calls at MidGul were found to have a statistically significant time of day with more calls than the others (p = 0.028), but which time of day had higher call frequency is unknown. Figure 12. Diel patterns in blue whale calls at each location. 23

28 Figure 13. Plot of Kruskal- Wallis test results for arch calls at MidGul. Arch calls were significantly more frequent during dusk than any other period of the day. Call Type Variability Dr. Moors- Murphy s analysts are now working on separating detected calls by call type for each recorder location. Thus far, only MidGul has been completely analyzed, but the results are very interesting. For the first year and a half, the predominant call type was tonal. Arch calls were found on less than 30 files from the beginning of deployment (September 2012) until the end of the third deployment (ending April 2014). However, in the second summer the fourth deployment files with arch calls comprised almost 93% of files with blue whale calls. DISCUSSION The results of this analysis are in agreement with Whitehead 2013, Hooker et al. 1999, and others who recognized the importance of the Scotian Shelf particularly the area of the shelf near the Gully for cetaceans. The calls detected also match prior scientific work on blue whale calls in the Northwest Atlantic (i.e., Mellinger & Clark 2003, and others). The abundance of arch calls during the last deployment the summer months could be used as further evidence to support the hypothesis that arch calls are related to foraging (i.e., Oleson et al., 2007a), since blue whales are known to forage along the Scotian Shelf in the summer. The discovery of winter peaks in blue whale calls will hopefully help direct future research efforts. 24

29 Management Implications The results of this study suggest that blue whales are around this part of the Scotian Shelf regularly, but there is variation. The peak in calls during the winter months was previously unknown, and thus provides a large contribution to future management decisions regarding species occurrence in this area. Perhaps more importantly, there were seismic surveys conducted during the second summer of the study, the same season which showed an unpredicted increase in blue whale calls (RPS Energy Canada, 2014). The surveys were conducted 100 kilometers away from the Gully, close enough to create a louder soundscape. While some cetaceans have been shown to decrease their calls during seismic airgun surveys (Goold, 1996), in fact blue whales have been shown to increase their vocal behavior as a response to seismic airgun noise (Di Iorio & Clark, 2010) and ship noise (Melcon et al., 2012). From May through August, 2014, the most files with detected blue whale calls came from the MidGul location, which could support the hypothesis that blue whales produce more calls in the presence of seismic surveys. The significant increase in blue whale calls during the second year of study might be able to help with future oil and gas survey regulations. In terms of habitat use, statistical review of consecutive hours of blue whale calls in other words, looking for files with detected calls that occur consecutively, or at least within twenty five minutes of each other determined that even on days where calls were detected almost every hour, the average amount of consecutive hours with calls was less than 3. This could mean that blue whales are just passing through this area, rather than staying and using the habitat for foraging or other activities. While this does not necessarily indicate that the habitat is not critical, it is important to keep in mind when discussing this particular habitat and future management steps to protect the species. Things to Note There are some important limitations to note regarding this study. First, the recording range of the AMARs is currently unknown; in other words, we do not know how far away a blue whale could be for its call to still be detected by the AMARs. JASCO is currently working to determine this range to better assess the usefulness of the data with regard to the nearby habitat. Second, the recorders were not synchronized prior to deployment or upon retrieval, so it is possible that there is overlap in vocalizations detected on different recorders. Third, it is important to remember that absence of blue whale calls does not indicate absence of whales; indeed, it is possible that blue whales were near the recorders but did not produce any noise. This becomes relevant when interpreting the results: while acoustic data provide a great deal of information, there are major components that 25

30 might be missing, that need to be kept in mind as well. Additionally, the data are still too inconclusive to meet the requirements for designation of critical habitat by DFO. Much more research is needed to investigate whether the trends identified thus far in blue whale call detections are regular, recurring patterns, or whether anomalous events (like the Summer 2014 seismic survey) caused changes in blue whale vocalizations, and potentially occurrence of the whales themselves. However, it is also important to remember that sometimes patterns and anomalies cannot be detected, even over longer periods of time, as in Širović et al., Passive acoustic monitoring offers many things visual surveys lack. PAM is unobtrusive and can provide continuous, long term data collection with minimal human effort (such as daily boat trips that are often weather- dependent and rely on searching for and following animals). However, it also has limitations. PAM does not allow for confirmation of blue whale presence within a given circumference of the recorder, if the whale is not vocalizing. Additionally, PAM is unable to determine how many whales are vocalizing or are present in the area (something visual surveys can do). Therefore, it cannot be used alone to determine critical habitat for blue whales. Future Recommendations Deploying more AMARs and synchronizing their timestamps could help with determining location of vocalizing blue whales. Additionally, more effort should be spent in Shortland and Haldimand canyons, using PAM as well as visual surveys to explore cetacean abundance in these areas. Effort should be year- round, since evidence from the current study suggests blue whales might be present in this area even during winter months. It is possible that these canyons should be designated MPAs, like the Gully, to aid in the conservation of marine mammals that occur there. Further studies should also work to localize calling whales, to determine presence within specific areas. Additionally, further study on the effects of anthropogenic noise on marine mammals is crucial and can play a significant role in determining critical habitat. Due to its benefits and its limitations, PAM should continue to be used, but should be supplemented with other forms of data collection. ACKNOWLEDGEMENTS Many thanks to Dr. Hilary Moors- Murphy, who developed the project and provided all the data, as well as endless insight and advice; and Jack Lawson at DFO for support. Additional thanks to Dr. Andrew J. Read for continuous counsel throughout this project, Dr. Douglas P. Nowacek for 26

31 assistance with the acoustic analysis, and the Environmental Internship Fund (EIF) of the Nicholas School of the Environment, Duke University, for financial assistance. William Cioffi and Lynne Hodge both provided invaluable contributions to the analysis. Finally, thank you to my family and friends for your continuous support and love. REFERENCES Beauchamp, J., Bouchard, H., de Margerie, P., Otis, N., & Savaria, J.- Y Recovery Strategy for the blue whale (Balaenoptera musculus), Northwest Atlantic population, in Canada [FINAL]. Species at Risk Act Recovery Strategy Series. Ottawa: Fisheries and Oceans Canada. Burtenshaw, J. C., Oleson, E. M., Hildebrand, J. A., McDonald, M. A., Andrew, R. K., Howe, B. M., et al Acoustic and satellite remote sensing of blue whale seasonality and habitat in the Northeast Pacific. Deep- Sea Research II, 51, CITES. The CITES Appendices. Retrieved from Convention on International Trade in Endangered Species of Wild Fauna and Flora: Clark, C. W., & Ellison, W. T Potential Use of Low- Frequency Sounds by Baleen Whales for Probing the Environment: Evidence from Models and Empirical Measurements. In J. A. Thomas, C. F. Moss, & M. Vater (Eds.), Echolocation in Bats and Dolphins (pp ). University of Chicago Press. COSEWIC About COSEWIC: Brief History. Retrieved from COSEWIC: COSEWIC COSEWIC status appraisal summary on the Blue Whale Balaenoptera musculus, Atlantic population, in Canada. Ottawa: Committee on the Status of Endangered Wildlife in Canada. Department of Fisheries and Oceans Canada. Canadian Science Advisory Secretariat (CSAS). Retrieved from Fisheries and Oceans Canada: mpo.gc.ca/csas- sccs/index- eng.htm Department of Fisheries and Oceans Canada The Gully Marine Protected Area Management Plan. Fisheries and Oceans Canada, Dartmouth. Department of Fisheries and Oceans Canada. 2010a. Recovery Strategy for the Northern Bottlenose Whale (Hyperoodon ampullatus), Scotian Shelf population, in Atlantic Canadian Waters. Fisheries and Oceans Canada. Department of Fisheries and Oceans Canada. 2010b. Gully Marine Protected Area Monitoring Indicators, Protocols and Strategies. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2010/066. Di Iorio, L., & Clark, C. W Exposure to sesimic survey alters blue whale acoustic communication. Biol Lett, 6,

32 Goold, J. C Acoustic Assessment of Populations of Common Dolphin Delphinus Delphis in Conjunction with Seismic Surveying. J Mar Biol Ass UK, 76, Government of Canada Species Profile: Blue Whale Atlantic population. Retrieved from Species at Risk Public Registry: Hooker, S. K., Whitehead, H., & Gowans, S Marine Protected Area Design and the Spatial and Temporal Distribution of Cetaceans in a Submarine Canyon. Conservation Biology, 13 (3), JASCO Applied Sciences Capability of the Autonomous Multi- channel Acoustic Recorder by JASCO Applied Sciences, Version 1.3. Document Dartmouth, Nova Scotia. McDonald, M. A., Calambokidis, J., Teranishi, A. M., & Hildebrand, J. A The acoustic calls of blue whales off California with gender data. J Acoust Soc Am, 109 (4), McDonald, M. A., Hildebrand, J. A., & Webb, S. C Blue and fin whales observed on a seafloor array in the Northeast Pacific. J Acoust Soc Am, 98 (2), McDonald, M. A., Mesnick, S. L., & Hildebrand, J. A Biogeographic characterisation of blue whale song worldwide: using song to identify populations. J Cetacean Res Manage, 8 (1), McKenna, M. K. 2013, February. Singing in a Crowded Ocean: Acoustic Adaptations of Great Whales and Human Impacts. In J. H. Lipps (Chair), Evolution of Giants: The Great Whales. Symposium conducted at the meeting of the American Association for the Advancement of Science (AAAS), Boston. Melcon, M. L., Cummins, A. J., Kerosky, S. M., Roche, L. K., Wiggins, S. M., & Hildebrand, J. A Blue Whales Respond to Anthropogenic Noise. PLoS ONE, 7 (2), e Mellinger, D. K., & Clark, C. W Blue whale (Balaenoptera musculus) sounds from the North Atlantic. J Acoust Soc Am, 114 (2), Moors- Murphy, H.B., Lawson, J.W., Gomez, C., Rubin, B., Marotte, E. and Renaud, G. In prep. Occurrence of blue whales (Balaenoptera musculus) off Nova Scotia, Newfoundland, and Labrador. DFO Can. Sci. Advis. Sec. Res. Doc Nieukirk, S. L., Stafford, K. M., Mellinger, D. K., Dziak, R. P., & Fox, C. G Low- frequency whale and seismic airgun sounds recorded in the mid- Atlantic Ocean. J Acoust Soc Am, 115 (4), Oleson, E. M., Calambokidis, J., Burgess, W. C., McDonald, M. A., LeDuc, C. A., & Hildebrand, J. A. 2007a. Behavioral context of call production by eastern North Pacific blue whales. Mar Ecol Prog Ser, 330, Oleson, E. M., Wiggins, S. M., & Hildebrand, J. A. 2007b. Temporal separation of blue whale call types on a southern California breeding ground. Animal Behaviour, 74 (4), Reilly, S. B., Bannister, J. L., Best, P. B., Brown, M., Brownell Jr., R. L., Butterworth, D. S., et al Balaenoptera musculus. The IUCN Red List of Threatened Species 2008 (T2477A ). Retrieved February 23, 2016, from The IUCN Red List of Threatened Species 2008: e.t2477a : 28

33 RPS Energy Canada Wildlife Observation Report: BP Tangier 3D WATS Seismic Survey. Halifax, Nova Scotia. Sears, R., & Calambokidis, J Update COSEWIC status report on the Blue Whale Balaenoptera musculus in Canada. In COSEWIC assessment and update status report on the Blue Whale Balaenoptera musculus in Canada (p. 32). Ottawa: Committee on the Status of Endangered Wildlife in Canada. Širović, A., Rice, A., Chou, E., Hildebrand, J. A., Wiggins, S. M., & Roch, M. A Seven years of blue and fin whale call abundance in the Southern California Bight. Endang Species Res, 28, Stafford, K. M., Nieukirk, S. L., & Fox, C. G Geographic and seasonal variation of blue whale calls in the North Pacific. J Cetacean Res Manage, 3 (1), Stafford, K. M., Moore, S. E., & Fox, C. G Diel variation in blue whale calls recorded in the eastern tropical Pacific. Animal Behaviour, 69, Whitehead, H Trends in cetacean abundance in the Gully submarine canyon, , highlight a 21% per year increase in Sowerby's beaked whales (Mesoplodon bidens). Can J Zool, 91, Wiggins, S Autonomous Acoustic Recording Packages (ARPs) for Long- Term Monitoring of Whale Sounds. MTS Journal, 37 (2), Wiggins, S. M., Oleson, E. M., McDonald, M. A., & Hildebrand, J. A Blue Whale (Balaenoptera musculus) Diel Call Patterns Offshore of Southern California. Aquatic Mammals, 31 (2),

34 APPENDIX Images of AMARs and Mooring Setup Courtesy of H. Moors- Murphy Figure 14. Autonomous Multichannel Acoustic Recorders (AMARs), JASCO Applied Sciences. Photo H. Moors- Murphy Figure 15. Moorings for AMARs. On the right is a modified mooring for the AMARs deployed in the Gully. Figure courtesy of H. Moors- Murphy. 30