Marine Mammal Species likely to be Encountered in the Coastal Waters of Virginia from Analysis of Stranding Data

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1 VAQF Scientific Report # 214-7a Prepared for the Virginia Department of Mines, Minerals and Energy Marine Mammal Species likely to be Encountered in the Coastal Waters of Virginia from Analysis of Stranding Data Submitted by: Susan Barco and W. Mark Swingle Virginia Aquarium & Marine Science Center Foundation

2 VAQF Scientific Report 214-7a Introduction There have been no consistent, year-round marine mammal surveys of the ocean waters off of Virginia since the late 197s (Scott et al. 1979). Data on marine mammal presence and seasonality are needed to inform state and federal agencies responsible for permitting offshore energy development and construction. A long term data set of marine mammal presence exists in the stranding record. Marine mammals often wash ashore sick, injured or dead and records of these stranding events can serve as a proxy of animal presence when no other data exist. Stranding data cannot provide information on species absence since an animal must strand in order to be counted, and deep water, offshore species rarely strand even though they may be plentiful. These data can, however, minimally provide a list of species to consider for survey efforts and, for more common and coastal species, suggest seasonal presence. Stranded marine mammals in Virginia The Virginia Aquarium & Marine Science Center Foundation (VAQF) Stranding Response Program has a database of marine mammal strandings in Virginia dating to In an earlier assessment, Potter (1991) documented a summary of the historical records of marine mammals from Virginia strandings. From these two sources, 32 different marine mammal species have stranded in Virginia: four pinniped species; 27 cetacean species, including four endangered species; and one endangered sirenian species (Table 1). Although none have stranded in Virginia, sighting data also indicate the seasonal and likely presence of Killer whales (Orcinus orca) and other species such as the false killer whale (Pseudorca crassidens) and blue whale (Balaenoptera musculus) in the region (Cummings et al. 214, Potter 1991, VAQF Stranding Database unpublished). Stranding records range from over 1,8 bottlenose dolphins (Tursiops truncatus) to a single stranding of a Sowerby s beaked whale (Mesoplodon bidens). The endangered species were primarily baleen whales and included humpback whales (Megaptera novaeangliae), fin whales (Balaenoptera physalus), sei whales (Balaenoptera borealis) and critically endangered northern right whales (Eubalaena glacialis). The endangered Florida manatee has stranded in Virginia and is regularly sighted on an annual basis. Two of the five most numerous marine mammal species in the stranding record were pinnipeds, harbor seals (Phoca vitulina) and harp seals (Pagophilus groenlandica). While healthy harbor seals are occurring in increasing numbers in Virginia and strand relatively rarely, most harp seals in Virginia, an ice seal species, are undernourished or sick weanlings and are therefore counted almost exclusively in the stranding record. This demonstrates one of the drawbacks of relying solely on stranding data for species presence. These data should therefore be used as a guide for developing survey designs. The other three species that most commonly stranded were bottlenose dolphin (Tursiops truncatus), harbor porpoise (Phocoena phocoena) and common dolphin (Delphinus delphis). These five species and the four endangered whale species are discussed in greater detail below. 1

3 VAQF Scientific Report 214-7a Table 1: Marine mammal species in stranding records from Virginia (ESA= listed under the U.S. Endangered Species Act). Location and seasonality data are included for species listed in bold. Historic refers to published accounts of the species. For these species, no animals were in the Virginia stranding record from Common Name Scientific Name ESA Strandings Baleen whales Bryde's whale Balaanoptera brydei Y historic fin whale Balaenoptera physalus Y 11 humpback whale Megaptera novaeangliae Y 33 minke whale Balaenoptera acutorostrata N 9 northern right whale Eubalaena glacialis Y 4 sei whale Balaenoptera borealis Y 2 Delphinids Atlantic spotted dolphin Stenella frontalis N 4 Atlantic white-sided dolphin Lagenorhynchus acutus N 14 bottlenose dolphin Tursiops truncatus N 1,93 Clymene dolphin Stenella clymene N C. Potter pers. comm common dolphin Delphinus delphis N 98 long-finned pilot whale Globicephala melas N 14 melon headed whale Peponocephala electra N 2 pantropical spotted dolphin Stenella attenuata N historic pygmy killer whale Feresa attenuata N 3 Risso's dolphin Grampus griseus N 22 rough toothed dolphin Steno bredanensis N 14 short-finned pilot whale Globicephala macrorhynchus N 7 striped dolphin Stenella coeruleoalba N 16 Other toothed whales Cuvier's beaked whale Ziphius cavirostris N historic dwarf sperm whale Kogia sima N 1 Gervais' beaked whale Mesoplodon europaeus N 6 harbor porpoise Phocoena phocoena N 318 pygmy sperm whale Kogia breviceps N 24 Sowerby's beaked whale Mesoplodon bidens N 2 sperm whale Physeter macrocephalus N 1 True's beaked whale Mesoplodon mirus N 1 Pinnipeds grey seal Halichoerus grypus N 1 harbor seal Phoca vitulina N 82 harp seal Pagophilus groenlandica N 38 hooded seal Cystophora cristata N 12 Sirenians Florida manatee Trichechus manatus Y annual sightings 2

4 VAQF Scientific Report 214-7a Endangered species The northern right whale (Eubalaena glacialis) is critically endangered under the U.S. Endangered Species Act, and there are estimated to be 444 individuals in the northwest Atlantic (Waring et al. 213). Northern right whales are a slow moving, coastal species that is susceptible to both vessel strikes and gear entanglements. Northern right whales spend the warm water months in high latitude waters feeding on copepods. In the fall, some individuals disperse from feeding areas in New England and Atlantic Canada. Breeding females travel to ocean waters off the Georgia/Florida border to calve. The winter distribution of non-breeding females, adult males and juvenile whales is unknown, but whales may move extensively between feeding and breeding areas. The mid-atlantic region is part of the migratory corridor between summer feeding areas and winter breeding areas and may also be a destination for non-breeding individuals. Since 1988, there have been four right whale strandings in Virginia, all since 21 (Figure 1). Three of the strandings occurred in winter (Jan-Mar) and one in late summer (Jul-Sep; Figure 2). All strandings were on ocean facing beaches suggesting that the animals were in ocean habitat. The whales ranged in size from m. Three were adult females, one pregnant with a full term fetus, and one was a male calf. The calf and the pregnant female had injuries consistent with ship strike. One whale most likely died from injuries caused by entangling line and the cause of death for the fourth animal could not be determined due to decomposition of the carcass Figure 2: Seasonality of Northern right whale strandings in Virginia from (winter=jan-mar; spring=apr-jun; summer=jul- Sep; fall=oct-dec). Figure 1: Location of northern right whale strandings in Virginia from

5 Number of strandings VAQF Scientific Report 214-7a Humpback whales (Megaptera novaeangliae) are the endangered species that stranded most often in Virginia with 33 animals reported since There are five stocks described based on feeding ground distribution. The Gulf of Maine stock of humpback whales is estimated to include 823 individuals (Waring et al. 213), but humpbacks that stranded or were observed live in the mid-atlantic have been identified to three different stocks: primarily the Gulf of Maine stock, but also the Gulf of St. Lawrence and Newfoundland stocks (Barco et al. 22). Humpbacks stranded primarily on ocean facing beaches but also stranded in Chesapeake Bay (Figure 3). Humpback strandings have occurred in all seasons (Figure 4) and in all months except December and January. Stranded humpback whales in Virginia ranged in size from 6.4 to 1.4 m, with most being juveniles (Figure ). For 22 of the 33 strandings, we could assess the whale for signs human interaction. Two of the animals had no signs of human interaction, eleven had marks consistent with entanglement and nine had wounds consistent with vessel strike Figure 4: Seasonality of humpback whale strandings in Virginia from (winter=jan-mar; spring=apr-jun; summer=jul- Sep; fall=oct-dec) Figure 3: Location of humpback whale strandings in Virginia from Length (cm) Figure : Length of stranded humpback whales in Virginia from Length was only available for 24 animals. 4

6 VAQF Scientific Report 214-7a Fin whales (Balaenoptera physalis) are the second largest whale species after blue whales and are listed as endangered in the U.S. The North Atlantic population is considered to be a single population (stock) and the best available estimate of abundance is 3,22 whales from 27 (Waring et al. 213). Fin whales are most commonly found from Cape Hatteras northward and spend the warmer months feeding in high latitude waters. It has been suggested that calving takes place in the fall and winter offshore of the U.S. mid-atlantic but no concrete evidence of overwintering exists (Waring et al. 213). Vessel strike is the most common cause of stranding for fin whales. Of the eleven fin whales that stranded in Virginia since 1988, we were able to conduct a human interaction evaluation on five animals. All five had evidence of vessel strike and one also had entanglement marks. We were able to collect a total length on seven carcasses and they ranged in size from m. There were three males and five females identified. Unlike humpback whale strandings, fin whale strandings occurred primarily in winter with one stranding each in spring and summer. Strandings occurred on both ocean-facing beaches and in Chesapeake Bay. One animal that was discovered in the port of Hampton Roads had marks consistent with being carried on the bow of a ship Figure 7: Seasonality of fin whale strandings in Virginia from (winter=jan- Mar; spring=apr-jun; summer=jul-sep; fall=oct-dec). Figure 6: Location of fin whale strandings in Virginia from

7 VAQF Scientific Report 214-7a Sei whales (Balaenoptera borealis) are listed as endangered species under the U. S. Endangered Species Act but relatively little is known about this species. Sei whales that appear in U. S. waters are thought to belong to the Nova Scotia stock of animals which is one of two proposed stocks in the northwest Atlantic. During the summer feeding season, most sei whales are distributed in high latitude waters and primarily offshore near the continental shelf edge, but they occasionally make incursions into coastal waters. Sei whale distribution in the cooler weather months is unknown. The Nova Scotia stock is estimated to include 37 individuals, although this is considered a conservative estimate (Waring et al. 213). There have been two sei whales that stranded in Virginia since 1988, the first in 23 and the second in 211. Both occurred in winter and had evidence of vessel strike. The animal found in the port of Hampton Roads had marks consistent with being carried on the bow of a ship Figure 9: Seasonality of sei whale strandings in Virginia from (winter=jan- Mar; spring=apr-jun; summer=jul-sep; fall=oct-dec). Figure 8: Location of sei whale strandings in Virginia from

8 VAQF Scientific Report 214-7a Common species The bottlenose dolphin (Tursiops truncatus) is the most common marine mammal to strand in Virginia waters. It is protected under the Marine Mammal Protection Act. Since 1988 more than 1, bottlenose dolphins have stranded in Virginia, averaging 6 animals per year from Bottlenose dolphins are consistently seen in Virginia waters from May through October (Barco et al. 1999) and are regularly sighted from early spring through late fall with sightings and strandings in all months of the year. Bottlenose dolphins in Virginia are considered migratory. Bottlenose dolphins strand Figure 1: Seasonal location of bottlenose dolphin strandings in Virginia from [winter (Jan-Mar) top left; spring (Apr-Jun) top right; summer (Jul-Sep) bottom left; fall (Oct- Dec) bottom right] 7

9 Number of strandings VAQF Scientific Report 214-7a on ocean facing beaches as well as in Chesapeake Bay and its tributaries. Most strandings occur near Cape Henry and Cape Charles at the mouth of Chesapeake Bay. Strandings usually peak in May or June which appears to be when calving occurs in the area. In 213, an Unusual Mortality Event (UME) for bottlenose dolphins along the Atlantic coast was declared and over 3 dolphins were recovered in Virginia alone. The seasonal pattern of strandings during the UME was unusual, with most animals recovered in July and August; therefore 213 is not included in the seasonality graph. As of the date of this report, the event continues with over 1,2 dolphins affected coast wide from New York through Brevard county Florida. The impact of this mortality event on the population and the numerous identified coastal stocks is unclear. The population structure of bottlenose dolphins is complex with an offshore stock located near the continental shelf edge and multiple migratory and resident coastal stocks close to shore and in estuarine waters (Waring et al. 213). The three coastal stocks that may occur in Virginia include approximately 22, individuals Figure 11: Seasonality of bottlenose dolphin strandings in Virginia from (winter=jan- Mar; spring=apr-jun; summer=jul-sep; fall=oct- Dec). 213 is not included in the graph because an unusual mortality event resulted in a different seasonal pattern. Figure 12: Annual bottlenose dolphin strandings in Virginia from An unusual mortality event resulted in the high numbers of strandings in 213. Dolphins of all life stages ( m) strand in Virginia waters, with young of the year and newly independent individuals making up the highest proportions of the mortality. Bottlenose dolphins are not often affected by vessel strikes but they are susceptible to entanglements and have been found in numerous types of fishing gear. 8

10 VAQF Scientific Report 214-7a Harbor porpoises are the second most common marine mammal to strand in Virginia waters with over 3 strandings since 1988 and 9 since 24. Harbor porpoises are the smallest cetacean in Virginia, and most animals that strand are juveniles m long. Harbor porpoises are generally found in coastal waters up to 1 m deep. Harbor porpoises in Virginia belong primarily to the Gulf of Maine/Bay of Fundy stock of animals that can be found in the U.S. northeast and Bay of Fundy in summer, but animals from the Newfoundland and Gulf of St. Lawrence stocks are also present in the mid-atlantic (Waring et al. 213) in winter. The Gulf of Maine/Bay of Fundy stock is estimated to include approximately 8, animals. Harbor porpoises are unlikely to be affected by vessel strikes but are susceptible to entanglement, especially in gill net gear. Unlike bottlenose dolphins, harbor porpoises are in Virginia in the cooler months, primarily late winter and early spring, and they strand primarily on ocean facing beaches Figure 14: Seasonality of harbor porpoise strandings in Virginia from (winter=jan- Mar; spring=apr-jun; summer=jul-sep; fall=oct- Dec). Figure 13: Location of harbor porpoise strandings in Virginia from

11 VAQF Scientific Report 214-7a Common dolphins (Delphinus delphis) regularly strand in Virginia and have mass-stranded several times since Ninety-eight common dolphins have stranded since 1998 with 71 since 24. They are protected by the U. S. Marine Mammal Protection Act. They are also the most common species to livestrand in our area. The common dolphin (in the western north Atlantic also called the short-beaked common dolphin) is one of the most widely distributed species worldwide and they typically occur over the continental shelf in waters 1-2, m deep and are often associated with the Gulf Stream (Waring et al. 213). Common dolphins are regularly seen north of Cape Hatteras North Carolina. From January to May they are found as far south as Cape Hatteras and typically spend the warmer water months in the U. S. northeast and Atlantic Canada. Abundance for the western north Atlantic stock is estimated to be around 68, individuals. Common dolphins typically strand in winter and early spring but have also occurred in summer and fall. They have stranded on ocean facing beaches as well as in Chesapeake Bay and, in two instances, more inland in river/canal systems. Common dolphins of all sizes have stranded in Virginia ( m) Figure 16: Seasonality of common dolphin strandings in Virginia from (winter=jan- Mar; spring=apr-jun; summer=jul-sep; fall=oct- Dec). 2 8 Figure 1: Location of common dolphin strandings in Virginia from

12 VAQF Scientific Report 214-7a Harbor seals (Phoca vitulina) are the most common pinniped in Virginia and began appearing in the stranding record in the early 199s. Harbor seals are protected by the U. S. Marine Mammal Protection Act. Since then, 82 seals have stranded and many healthy animals have been sighted hauled out on beaches and other structures. Currently, no surveys have sighted harbor seals in Virginia s ocean waters, but winter and spring sightings are common along ocean beaches and on structures in the lower Chesapeake Bay (Waring et al. 213, VAQF unpublished data). The western north Atlantic population of harbor seals is described as commonly occurring from arctic Canada south into New York and occasionally in the Carolinas. There is currently no population estimate for western north Atlantic harbor seals but the population is thought to be increasing. Most stranded harbor seals are juvenile animals thought to be one to two years old. Pupping occurs in the late spring and summer from New England north, and the animals that strand in Virginia in winter and spring are most likely the previous year s pups. Stranded harbor seals have ranged in size from m in length. Harbor seals are rarely affected by vessel strikes but are susceptible to entanglement. Harbor seals primarily strand on ocean-facing beaches and in the lower Chesapeake Bay Figure 18: Seasonality of harbor seal strandings in Virginia from (winter=jan-mar; spring=apr-jun; summer=jul-sep; fall=oct-dec). Figure 17: Location of harbor seal strandings in Virginia from

13 VAQF Scientific Report 214-7a Harp seals (Pagophilus groenlandica) are considered ice seals and are thought to spend most of their lives north of the U.S./Canada border. Since the late 199s, however, harp seals have been appearing in the Virginia stranding record with most of the 38 strandings occurring since 24 (n=31) (VAQF unpublished data). Harp seals are highly migratory, with females pupping on pack ice in Canada and Greenland between late February and April, and animals moving into the arctic in summer. Juveniles are thought to primarily spend the winter months off the coast of Newfoundland (Waring et al. 213). The western north Atlantic stock is estimated to include over 8 million individuals. In the U.S., harp seals are protected by the Marine Mammal Protection Act. All Virginia strandings since 24 were juveniles with the speckled, beater coat pelage, ranging in size from m. Harp seals most commonly strand in the winter and early spring with one record in late summer. Unlike harbor seals, healthy harp seals are rarely sighted in Virginia and the stranded animals may represent the majority of the animals present in the region. Harp seals are unlikely to be affected by vessel strikes in the area but they are susceptible to entanglement Figure 2: Seasonality of harp seal strandings in Virginia from (winter=jan-mar; spring=apr-jun; summer=jul-sep; fall=oct-dec). Figure 19: Location of harp seal strandings in Virginia from

14 VAQF Scientific Report 214-7a Summary While the species highlighted here represent those animals that are likely to be encountered by, and thus affected by, offshore energy development, the number of strandings does not indicate abundance, and absence of strandings does not indicate absence of healthy animals in Virginia s coastal waters. Only dedicated, year round survey effort can provide these data. Offshore species such as beaked whales and offshore delphinids are likely under-represented in the stranding record while amphibious species such as the pinnipeds may be over-represented. This report provides insight into species that may be encountered when surveys are conducted and provides an indication of those species that may be affected by future development. All of the endangered whale species are susceptible to vessel strikes, especially the critically endangered northern right whale, and all species are acoustically active and may be affected by noise from geophysical surveys, construction and operations associated with offshore energy installations. To properly assess seasonal abundance and distribution of marine mammals in Virginia, a combination of survey techniques including aerial and vessel based surveys as well as acoustic monitoring (passive and/or active) is recommended (BOEM 213). Convening a workshop of marine mammal survey experts to review existing data and determine the most appropriate survey design(s) for marine mammals would insure that the best survey design(s) are employed and that existing data be taken into account in survey designs. Such a workshop could be completed as a two day meeting to first understand historic and existing data and survey efforts and second to develop survey and monitoring plans for marine mammals, sea turtles, birds and other species of interest in waters around the Virginia WEA. Topics could include: Establishing minimum data needed for endangered and protected species Identifing non-endangered species of concern that may be impacted by wind-energy development Develop comprehensive monitoring plan for species of concern Plan for monitoring vessel traffic using AIS and RADAR from liftboat or other research platform(s) Development of a passive acoustic deployment plan for potential real-time monitoring Review of sonic tag data and potential deployment of underwater acoustic detectors on liftboat or other research platform(s) and throughout the WEA. Acoustic data would provide information on presence of tagged animals such as sea turtles and certain fishes. Discuss feasibility of remote camera(s) on research platforms (potentially above and below water) with shore-side links, such as to Virginia Aquarium exhibits/programs Potential Invitees would include aerial survey experts, passive acoustic experts, GIS/RADAR/AIS experts, boat-based survey experts, bird experts ecology and survey experts, survey technology (high def video/drone) experts, mobile research platform experts, BOEM representative(s), NMFS representative(s), USFWS representative(s), and DMME representative(s). 13

15 VAQF Scientific Report 214-7a Literature Cited Barco, S. McLellan, W. Allen, J. Asmutis-Silvia, R., Mallon-Day, R., Meagher, E., Pabst, D.A., Robbins, J., Seton,R., Swingle, W.M., Weinrich, M. and Clapham, P. 22. Population identity of humpback whales, Megaptera novaeangliae, in the waters of the U.S. mid-atlantic states. Journal of Cetacean Research and Management 4: Barco, S.G., Swingle, W.M., McLellan, W.A., Harris, R.N., and Pabst, D.A Local abundance and distribution of bottlenose dolphins (Tursiops truncatus) in the near shore waters of Virginia Beach, Virginia. Marine Mammal Science 1(1): Bureau of Ocean Energy Management. (213). Guidelines for providing information on marine mammals and sea turtles for renewable energy development on the Atlantic outer continental shelf pursuant to 3 CFR Part 8. newable_mmandst_guidelines.pdf (accessed 1 June 214) Cummings, E. W., Pabst D. A., Blum, J. E., Barco, S. G., Davis, S. J., Thayer, V. G., Adimey, N. & McLellan, W. A. (214). Spatial and temporal patterns of habitat use and mortality of the Florida manatee (Trichechus manatus latirostris) in the mid-atlantic states of North Carolina and Virginia from 1991 to 212. Aquatic Mammals 4(2): , DOI 1.178/AM Potter, C. W. (1991). Marine mammals. In K. Terwilliger (coordinator) Virginia s Endangered Species: Proceedings of a Symposium. pp Scott, G. P., Kenney, R. D., Gilbert, J. G., & Edel, R. K. (1979). Estimates of cetacean and turtle abundance in the CETAP study area with an analysis of factors affecting them. A characterization of marine mammals and turtles in the Mid-and North-Atlantic areas of the US outer continental shelf, Annual Report to the International Whaling Commission, Waring, G. T., Josephson, E., Maze-Foley, K., & Rosel, P. E. (213). U.S. Atlantic and Gulf of Mexico marine mammal stock assessments-212: Volume 1. Retrieved June 6,