Project Overview Whales in Fjords: The pre-tanker ecology of inland whales, seabirds, & their prey in the northern Great Bear Fjordland, B.C. Eric Keen Scripps Institution of Oceanography 2013 Methods “Bangarang” Methods 2013 E.M. Keen Draft 13 November 2013. To offer recommendations or concerns, please contact: Eric Keen Scripps Institution of Oceanography 9500 Gilman Drive, Mail Code 0208 La Jolla, CA 92093-0208 [email protected] 707.238.2232 Bottom cover image by Janie Wray, North Coast Cetacean Society. All photographs by Eric or the crew of the 2013 Bangarang field season unless otherwise noted. 2 “Bangarang” Methods 2013 E.M. Keen Contents Synopsis ………………………………………………………………………. 4 Study Area …………………………………………………………………… 6 Methods ……………………………………………………………………….. 7 Study Plan ……………………………………………………………. 7 Vessel ………………………………………………………………… 11 Stations ……………………………………………………………….. 13 Meteorology…………………………………………………. 13 Water Column Sampling …………………………………………. 13 Zooplankton tows ………………………………………….. 15 Transects ……………………………………………………………... 19 Acoustic Surveys …………………………………………… 21 Visual Surveys …………………………………………….. 23 Bangarang Range Finder ………………………………… 25 Observer Positions ………………………………………… 26 Observer Training ………………………………………… 27 Data Management ………………………………………………….. 28 Logistics ……………………………………………………………..……….. 29 Protocols …………………………………………………………….. ………. 31 On Transect ………………………………………………………….. 31 Closing ………………………………………………………………… 32 With Whales …………………………………………………………. 33 Returning to the Trackline ………………………………………… 36 Literature Cited ……………………………………………………………. 37 Related Materials: - 2013 Field Season Report & Preliminary Data - The “Bangarang Bible”: Standard Operating Procedures - Research Underway: Bangarang User’s Manual - RUB software and project files 3 “Bangarang” Methods 2013 E.M. Keen Project Synopsis Endangered baleen whales are now reinvading the temperate fjords of British Columbia's north coast. There, at the interface of the Great Bear Fjordland and the subarctic Pacific, fin and humpback whales have begun to use the protected, productive waterways to forage intensively and socialize. Their return raises questions about the current and past importance of such fjords to species that have historically been considered offshore. As their populations continue to recover from 20th century whaling, how and to what extent will they come to rely on this habitat? Conversely, what is the potential importance of these whales to the ecological function of the north coast? These academic questions have become applied in light of proposed crude oil and natural gas tanker routes through the Great Bear waterways. How will unprecedented vessel noise, ship strikes, and possible spills impact these inland whales, and by extension the place as a whole? Answers here are difficult. As mobile predators whose habitat use depends entirely on transient prey conditions, the response of whales and seabirds to maritime development cannot be assessed by counting the predators alone. The biological oceanography of the place must be monitored on multiple trophic levels. I see my dissertation as an opportunity to study the foraging strategies and ecology of these inland whales while simultaneously collecting baseline data for the impact assessment of escalated resource trafficking in the Great Bear. In summer 2013, with support from the National Geographic Society and Waitt Foundation, I conducted 4 months of visual, acoustic, and oceanographic surveys within a broad transect of the northern fjords. Data were collected from the SV Bangarang, my 12m motorsailer, in close collaboration with the Gitga’at First Nation, the North Coast Cetacean Society, and Canada’s Department of Fisheries and Oceans. My crew of three performed repeated circuits of the study area throughout the summer. In each circuit we conducted water column sampling (CTD, Secchi, and zooplankton net casts) at 24 stations. In transit between stations we conducted three line-transect surveys concurrently: 1) distance sampling for marine mammals and vessels; 2) strip-width sampling for seabirds, jumping salmon and tidal features; and 3) echosounder transects at 38 and 200 kHz to map schools of fish and zooplankton. When whales were seen, they were approached for detailed behavioral observations, photo-identification, fecal collection, passive acoustic recordings with a towed hydrophone array, and echosounder imagery of their surrounding prey field. Special focus was given to fin whales, the newest arrival species to the fjordland and the least studied. This study design, when replicated multiple times per season for multiple seasons, will allow me to broadly characterize the geographic and temporal dynamics of the Great Bear’s summer pelagic ecosystem. Several aspects of local oceanography, including water column structure, zooplankton diversity, and the seabird community, remain poorly studied. Moreover, I will be able to offer quantitative answers to questions regarding the relationship between fjordland tetrapods and their prey prior to any impacts imposed by tankers. These questions include: 4 “Bangarang” Methods 2013 E.M. Keen - Local population geography: How many baleen whales and seabirds are using this habitat, and how does that use change spatially and behaviorally throughout the summer? - Threshold foraging: What are the prey conditions (relative density, depth, and patchiness of schools) in which cetaceans and seabirds are foraging, and how do they compare to ambient conditions in the study area? - Spatial foraging: At what spatial scales are whale and seabird predator distribution most tightly coupled to prey conditions, and how is this influenced by their competition or cooperation during feeding? - Fin whale acoustics: Are fin whales vocalizing in the study area? If so, what behaviors or conditions are associated with their call rates? This will determine the potential efficacy of passive acoustic monitoring for mitigating ship strikes of this endangered species. - Baseline for assessment, basis for mitigation: Are oceanographic changes within the study area, and the response of whales to those changes, predictable enough to inform a policy of adaptive tanker traffic control that minimizes impacts to whales? My first season of fieldwork has provided a proof of concept for this project, a fine-tuned survey design, and preliminary data with which to prepare my analytical approach. I now seek funding for summer 2014. A key advantage to small-craft research is its cost-effectiveness; my entire 2013 season cost less than one day on a Scripps research ship. In addition to improvements in vessel operations and equipment for next season, I hope to cover the subsistence costs of crew so that I can attract high-caliber researchers as well as host students from the local Gitga’at village of Hartley Bay. I believe this study has demonstrated potential, both academic and applied, and I’m looking forward to getting back out there. 5 “Bangarang” Methods 2013 E.M. Keen Study Area The study area comprises a broad (1,220 km2) inshore-offshore transect of the inland waterways in northern British Columbia, Canada, where the northern Great Bear Fjordland meets the Pacific waters of Hecate Strait (Fig. 1). This area is 86.87 km long north-south and 37.59 km across at its widest. It extends from Caamano Sound to the north end of Gribbell Island, and is nested within the marine territory of the Gitga'at First Nation. This area was delineated as such to be (1) relevant to local management and impact assessment needs, (2) biologically relevant, comprising the typical inland range of baleen whales in this sector of BC’s north coast, and (3) practical, accounting for the potential range of our vessel, the interests of our collaborators, re-supply locations, safety concerns, sea state and weather patterns, and viable anchorages (after Dawson et al. 2008). While the entirety of British Columbia’s 27,000 km coastline is complex, this area comprises one of only its few deep fjordlands that open directly to the Pacific. These exposed archipelagoes are separated by relatively closed sections of shoreline, such that comparable habitats are a several days’ voyage to the north and south of the area (as the Bangarang flies): Dixon Entrance to the north and Fitz Hugh Sound to the south. The study area is therefore semi-enclosed by natural boundaries, rendering it an ideal system for focused study. Figure 1. The study area. 6 “Bangarang” Methods 2013 E.M. Keen Methods Study Plan ●● ● Transect ● ● Station We performed repeated circuits of the study area, consisting ●● ● of systematic water column sampling at a psueod-systematic ● ● ● grid of stations, visual and acoustic transects between those ● ● stations, and thorough investigations of all marine mammal ● ●● ●● ● 53.4 sightings whenever they occur. (Fig. 2) ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● Our goal is to complete four “oceanographic” circuits and four ●● ● ● ● ●● additional “predator-prey” circuits of this area within the ● ● ● ●● summer season. This distribution of effort allows for higher- ● ● ● ● ) ° ● ● ( ● quality, more intensive circuits at the calculated cost of less ● ● ● 53.2 ● ● repetition. However, more intensive surveys at broader time ● ●● ● ● ● ● ● intervals can remain effective at detecting trends (Dawson et Latitude ● ● ● al. 2008). We attempt to complete each circuit within two ●● ● ● ● ● ● weeks, which normally allows ample time for weather, ● ● ●● repairs, and recuperation between circuits. The circuit is ● ● ● partitioned into 9 geographic blocks, each