Second Interim Report to ORPC on Bird Studies in Cobscook Bay, Maine First Winter Season Period of Investigation November 21 - May 211 Prepared by Peter D. Vickery, Ph.D. Center for Ecological Research and Chris Bartlett Maine Sea Grant University of Maine Cooperative Extension July 211 DRAFT 1
Introduction The Center for Ecological Research (CER) conducted waterfowl and seabird inventories off the waters of North Lubec where Ocean Renewable Power Company (ORPC) plans to install a TidGen Power System (Fig. 1). CER monitored the waters off North Lubec from November 21 through May 211. The purpose of these inventories was to determine the species and numbers of seabirds, and other birds that use the proposed deployment area of the TidGen Power System, the onshore Landing Site where the bundled cables are likely to come ashore in North Lubec, and the waters immediately off the Landing Site. We also wanted to determine the behaviors of the species that used these specific areas. These results should help determine whether the presence of ORPC s TidGen Power System might potentially impact the birds that use these specific parts of eastern Cobscook Bay, and it should provide guidance to ORPC to minimize potential impacts when it deploys and operates its equipment. Background Cobscook Bay is a rich marine environment with 5-7 meter tides and strong currents (Larsen 24). This bay is an important fishing area and we regularly observed 12-2 scallop draggers in the bay during our surveys in December to February. Numerous salmon pens are also scattered throughout the bay; boats service these pens on a daily basis. Cobscook Bay is considered an important area for wintering ducks, especially American Black Ducks (Longcore and Gibbs 1988). This bay also supports substantial numbers of seaducks (C. Bartlett, pers. obs.) but it is unclear whether ducks and other seabirds use the eastern portions of Cobscook Bay, especially the deployment area. Large numbers of Razorbills (Alca torda) are also known to occur in winter in the Bay of Fundy and nearby Grand Manan Island, New Brunswick (Huettmann et al. 25). Seaducks (scaup, eiders, scoters, Long-tailed Duck, goldeneyes, mergansers), loons, grebes, cormorants, and alcids are all diving birds foraging for benthic invertebrates or fish. Although most species dive to shallow depths (2-1 meters), a few species can dive to depths of over 1 meters (Table 1) and it is possible that these diving birds might interact with the bottom-mounted submerged TidGen Power System, which is expected to be approximately 25 meters below the surface at low tide. Because of this potential interaction, we were interested in documenting the number of diving birds that use the deployment area and Landing Site, along with these birds behaviors. We paid specific attention to species known to dive to depths of 2 meters or more; these include: Long-tailed Duck, White-winged Scoter, Common Loon, Black Guillemot, and Razorbill (Table 1). 2
Table 1. Diving depths of waterbirds and seabirds known to occur in Cobscook Bay, North Lubec, Maine. 1 Diving depths taken from species accounts, Birds of North America (see Literature Cited). WATERFOWL Diving Depth Food Taken Occurrence in Cobscook Bay Greater Scaup Aythya marila 7. meters 1 Benthic Invertebrates Common Common Eider Somateria mollissima +/- 1 meters 1 Benthic Invertebrates Common Surf Scoter Melanitta perspicillata 9 meters 1 Benthic Invertebrates Common White-winged Melanitta fusca 5-2 meters 1 Benthic Invertebrates Common Scoter Black Scoter Melanitta americana 3- <1 meters 1 Benthic Invertebrates Common Long-tailed Duck Clangula hyemalis 66 meters 1 Benthic Invertebrates Common Bufflehead Bucephala albeola <3 meters 1 Benthic Invertebrates Common Common Goldeneye Bucephala clangula 2-9 meters 1 Benthic Invertebrates Common Hooded Merganser Lophdytes cucullatus <1 meters 1 Fish and crustaceans Uncommon Red-breasted Merganser Mergus serrator 5-1 meters 1 Fish and crustaceans Common LOONS AND GREBES Red-throated Loon Gavia stellata 2-9 meters 1 Fish and crustaceans Rare Common Loon Gavia immer to 6 meters 1 Fish and crustaceans Common Horned Grebe Podiceps auritus < 1 meters 1 Fish and crustaceans Uncommon Red-necked Grebe Podicaps grisegena < 1 meters 1 Fish and crustaceans Uncommon CORMORANTS Double-crested Cormorant Phalacrocorax auritus <8 meters 1 Fish Common Great Cormorant Phalacrocorax carbo <2 meters 1 Fish Common ALCIDS Thick-billed Murre Uria lomvia to 21 meters 1 FIsh and invertebrates Rare Razorbill Alca torda 1 - >1 m 1 Schooling fish Occasional Black Guillemot Cepphus grylle 5-35 meters 1 FIsh and invertebrates Common We paid special attention to federal and state endangered, threatened, and special-concern species and communicated with the Maine Department of Inland Fisheries and Wildlife to confirm that the updated list of these bird species in Maine was accurate (http://www.maine.gov/ifw/wildlife/species/ endangered_species/state_federal_list.htm; see Appendix 1). STUDY OBJECTIVES The objective of this study was to determine the species and numbers of seabirds, and other birds that use the proposed deployment area of the TidGen Power System. CER also wanted to determine which species used the onshore Landing Site where the bundled cables are likely to come
ashore, and the waters immediately off the Landing Site. We also wanted to determine the behaviors of these seabirds. SURVEY SITE ORPC Landing Site - North Lubec We used the ORPC Landing Site in North Lubec as the location for our land-based observations because we wanted to determine the species composition, numbers, and behavior close to this proposed facility area where the place where the bundled power and data cables for the TidGen Power System are likely to come ashore. We conducted the land-based surveys from the defunct landing dock. We used these land-based surveys to determine which species used the Landing Site and the waters immediately adjacent to the Landing Site (Fig. 2; A) and the mid-channel surrounding the deployment area (Figs. 1 and 2; B). Because the distance from the Landing Site to the center of the deployment area was so great, approximately 8 meters, it was not possible to accurately define the 2-meter deployment area radius from the North Lubec Landing Site. The land-based surveys covered a broad mid-channel area (B in figure 1). We also surveyed the beach east at the Landing Site. Figure 1. Land-based surveys were conducted from the Landing Site in North Lubec, Maine. The surveys was separated into the near shore area (A) just offshore from the Landing Site and the mid- 4
channel area (B) where the TidGen Power System is likely to be deployed. The beach east of the Landing Site (yellow arrow at ORPC Landing Site) were also monitored. The land-based survey area for the nearshore Landing Site and the mid-channel was delineated by an imaginary line extending from the ORPC Landing Site to the east end of Goose Island (Fig. 1). The west side of the survey area was defined by a line extending from the western boundary of the Landing Site to a white building on a salmon farm directly northwest of the Landing Site. The northern edge of the inshore area (A) was marked by a green navigation buoy north of the Landing Site. The mid-channel area (B) was delimited by the green buoy and a yellow marker west of Goose Island. The beach and adjacent pond to the east of the Landing Site were clearly visible from this position. The two separate areas in the water surveys (mid-channel, nearshore area) were not independent. If one or more birds moved from one survey area to another area during a 15-minute survey, these birds were included in both areas because they occupied both areas during the survey period. SURVEY METHODS This phase of this study documented the number of wintering waterfowl and seabirds that used the North Lubec Landing Site and the general deployment mid-channel area. Wintering Waterfowl and Seabirds Starting in November, CER continued surveys for wintering waterfowl and seabirds from the Landing Site at North Lubec. Each survey was conducted for a period of 3-5 hours. Each survey was divided into 15-minute periods and the maximum number of each species and its behavior (see below) was recorded during each period. For reporting purposes, CER condensed the 15-minute observation periods into hour units by selecting the largest count in each of the four 15-minute periods. We then used the average of these hour counts to determine the number of individuals present for each survey date (see Figs. 2 - X). CER also conducted 2 dawn surveys from North Lubec to determine whether there was a dawn feeding period for waterfowl and seabirds. Behaviors We registered all behaviors of birds on the water s surface. Birds were identified as Loafing (floating on the surface), Diving (active feeding below the surface), or Surface Feeding (active feeding on the surface) (Holm and Burger 22). Birds that flew past the survey area but did not land on the water were recorded but were not included in this report. Observers used 8x or 1x binoculars and a 2-6x telescope for the land-based surveys. We used a continuous scan method to identify and count all species present (Martin and Bateson 1986).
RESULTS CER conducted ten land based surveys from North Lubec between November 7, 21 and May 14, 21 (Table 2). These surveys totaled 39 hours of observation time. Survey Site Date (21-211) Duration (hrs) High Tide Landing Site 7 Nov 3 1:59 Landing Site 13 Nov 3 4:15 Landing Site 27 Nov 5 2:55 Landing Site 15 Jan 4 15:42 Landing Site 3 Jan 4 8:9 Landing Site 5 Feb 4 12:43 Landing Site 12 Feb 4 5:29 Landing Site 5 March 4 11:41 Landing Site 13 March 4 5:34 Landing Site 14 May 4 9:8 Table 2. Surveys of the area of interest for ORPC in eastern Cobscook Bay, Maine were conducted from the Landing Site in North Lubec. This table provides the locality, date of survey, duration of survey, and the time of high tide. Waterfowl and Seabirds CER conducted two dawn surveys to determine whether there is a dawn feeding period for waterfowl and seabirds. CER found no evidence that waterfowl or seabirds concentrated in the study area to feed at dawn. We recorded numbers of waterfowl flying west into Cobscook Bay at dawn but these ducks flew over and past the deployment area and did not remain in the survey area. Data for waterfowl movements into and out of Cobscook Bay are not included in this report because these birds did not settle anywhere in the area of interest for the ORPC project. Common Eider was the only species of waterfowl to use the mid-channel and nearshore area off North Lubec in any numbers (Fig. 2) and were observed primarily in the mid-channel area. The maximum count in the near shore area was 25 individuals on January 15, 211 (Fig. 2). Common Eider numbers fluctuated in the mid-channel. They were present consistently in the mid-channel area from November 7, 21 to Jan 3, 211 but were nearly absent on February 5, 211 before appearing once more on February 12, 211 (average of 185.5 individuals). Eider numbers had diminished on March 5, 211 (average, 4.5 individuals) but increased by March 13, 211 (average 12.3 individuals) (Fig. 2). 6
Number 2 16 12 8 4 Common Eider Figure 2. The average number of Common Eiders through November in the Cobscook Bay study area, Maine, but the speciesʼs presence was somewhat irregular in late winter. Most eiders were observed in the mid-channel (green histograms). Long-tailed Ducks were uncommon and occurred in small numbers with a maxima of 5.5 individuals in the mid-channel on January 15, 211. Three species of dabbling ducks (Mallard [Anas platyrhynchos], American Black Duck [Anas rubripes], Northern Pintail [Anas acuta]) were observed exclusively in the near shore area, usually along the shore line. Dabbling duck numbers increased from January to early March 211 but diminished thereafter. 4 3 2 1 Number Dabbling Ducks Figure 3. The number of dabbling ducks in the near shore of North Lubec, Maine, increased between January and March 5, 211 when CER recorded a maxima of 3.6 individuals.
Red-breasted Mergansers were first observed in November and occurred in small numbers in the near shore area and the mid-channel. We recorded a peak count of 1. individuals on March 13, 211. 12 Number Red-breasted Merganser 9 6 3 Figure 4. Red-breasted Mergansers occurred in small numbers in both the near shore and the midchannel of the study area of Cobscook Bay, Maine. Other ducks were generally uncommon and irregular. We did not observe any scoters on 6 separate surveys but briefly observed 2 White-winged Scoters in the mid-channel area for a single 15- minute sampling period on January 15, 211 (average 55.5 individuals). Common Goldeneyes were seen in the near shore at North Lubec on 6 surveys with the maximum average number of 1.5 individuals on January 211. We observed two Hooded Merganser (Lophdytes cucullatus) in the near shore (average.5 individuals) and also in the mid-channel area on November 13, 211. A single Barrowʼs Goldeneye (Bucephala islandica) was seen in near shore on Feb 12, 211. Common Loons were regular in small numbers in the study area and were resident throughout the winter (Fig. 5). We observed Red-throated Loon (Gavia stellata) on two occasions: in near shore (average 1. individuals) and mid-channel (average.2 individuals) on Nov 27, 21 and in the midchannel on March 13, 211 (average.3). Number 8
6 Common Loon 4 2 Figure 5. Small numbers of Common Loons were regular in the study area of Cobscook Bay, Maine,and were found in the nearshore area of North Lubec (blue histograms) and in the mid-channel (green histogram). These birds appeared to be resident and we detected no obvious movement of wintering loons. Red-necked Grebes were regular in small numbers in both the near shore area (blue histogram) and also in the mid-channel (green histograms) in Cobscook Bay (Fig. 6). A single Horned Grebe (Podiceps auritus) was seen in the near shore area on February 12, 211 (average.8). 16 12 Number 8 4 Red-necked Grebe Figure 6. Red-necked Grebes occurred in small numbers with a maximum of 1 individuals in the mid-channel on March 13, 211. This species was less numerous in the near shore area off North Lubec, Maine. Great Cormorants (Phalacrocorax carbo) and Double-crested Cormorants (Phalacrocorax auritus) were present in small numbers (Fig. 7). Double-crested Cormorants were observed until November 13, 21 and then departed the area, migrating south. The first spring migrant Double-crested Cormorants were observed on May 14, 21. Great Cormorants, the regular wintering cormorant
species in Maine, were present from January 15, 211 to March 13, 211, when they migrated from the area. We counted a maxima of 1.5 Great Cormorants on January 15, 211. Number 12 Cormorant species 9 6 3 Figure 7. CER counted a maxima of 1.5 cormorants on January 15, 211. Black Guillemots (Cepphus grylle) were uncommon in winter. CER observed fewer than three individuals per survey in the mid-channel or the near shore during the period between November 7, 21 and May 15, 211 (Fig. 8). Razorbills (Alca torda) were very uncommon and were observed on two occasions: three Razorbills were seen in the mid-channel on Nov 27, 21 (.8 individuals) and one individual was observed in the mid-channel on Feb 5, 211 (.3 individuals). 4 3 2 1 Number Black Guillemot Figure 8. Black Guillemots were regular in small numbers in both the near shore area (blue histogram) and also in the mid-channel (green histograms) in Cobscook Bay, Maine. 1
Large gull species were comprised of Great Black-backed Gulls (Larus marinus) and Herring Gulls (Larus argentatus). Large gulls were present in small numbers except in the mid-channel on January 15, 211, when we observed an average of 5.3 Great Black-backed Gulls and 34.5 Herring Gulls (Fig. 9). Late migrant Bonaparteʼs Gull were observed in mid-channel on November 13, 21 (average.8 individuals), and.3 in near shore on November 27, 21 (average.3 individuals). Black-legged Kittiwake (Rissa tridactyla) feeding in mid-channel on Nov 7, 21 (average 1.5 individuals). The only Ring-billed Gull (Larus delawarensis) was seen in near shore of North Lubec on 3 Jan 211. 4 3 2 1 Number Large Gulls Figure 9. Large gulls were found in small numbers in both the near shore and mid-channel areas in Cobscook Bay, Maine. Nearly 4 large gulls (average of 5.3 Great Black-backed Gull and 34.5 Herring Gulls) were observed on January 15, 211. Diving Behavior During the winter months, diving waterfowl and seabirds spent most of their time actively feeding (Table x). Long-tailed Duck, Red-breasted Merganser, Common Goldeneye, Common Loon, Rednecked Grebe, and the cormorant species were observed diving >8% of the time. Common Eiders were observed diving 65%. This differed substantially from the fall season when eiders fed 29%. Black Guillemots were observed diving 76% of the time. In general, the percent time feeding in the mid-channel area and the near shore area were very similar for all species except Common Eider which fed in the mid-channel 48% and in the near shore area off North Lubec 8%, respectively. Non-diving species, Dabbling Ducks fed 87%, and Large Gull species fed 64% of the time, respectively. Table X. All of the regularly occurring waterfowl and seabirds in the study area in eastern Cobscook Bay, Maine were observed actively feeding (% of time) during the winter of 21-211.
Species Time Feeding (%) Common Eider 65 Long-tailed Duck 89 Scoter spp. 5 Red-breasted Merganser 86 Common Goldeneye 84 Dabbling Ducks 87 Common Loon 86 Red-necked Grebe 82 Cormorant spp. 83 Large Gull spp. 64 Black Guillemot 76 Bald Eagle One to four Bald Eagles were seen on every survey in the study area. Usually this species was seen flying over the study area. Formerly, Bald Eagles were listed as federally and state endangered, but this species was down listed to threatened and is no longer listed at any level (http://www.maine.gov/ ifw/wildlife/species/endangered_species/state_federal_list.htm). Otherwise, there was no activity along the beach and immediate shoreline. DISCUSSION Wintering Waterfowl and Seabirds: Generally, few ducks and seabirds used this section of Cobscook Bay in the winter of 21-211. Common Eider was the most common species with >1 individuals seen on three separate occasions (Fig. 2). Two hundred White-winged Scoters appeared briefly in the mid-channel on January 15, 211 but remained for less than 15 minutes and never reappeared in large numbers. This species was observed flying west into the upper reaches of Cobscook Bay on several occasions, but the fact that it did not return to the general deployment area appears to indicate that this area does not provide adequate feeding habitat for this species. Throughout the winter survey period, Common Loons, Red-necked Grebes, Red-breasted Mergansers, and cormorants were present in small numbers, typically 2-1 individuals. We usually recorded fewer than two Black Guillemots on most winter surveys, which was fewer than during the fall when we had 12
regularly observed 1-2 individuals. Dabbling Duck (American Black Duck, Mallard, Northern Pintail) numbers increased through the winter, reaching a peak of 3 individuals March 5, 211. These birds usually fed along the shoreline approximately 1-2 meters east of the Landing Site. Diving Behavior: Long-tailed Duck, Red-breasted Merganser, Common Goldeneye, Common Loon, Red-necked Grebe, and the two species of cormorants were observed actively diving >8% of the time. Black Guillemots were observed diving 76% of the time and Common Eiders 65%, respectively. Feeding activity was similar in the near shore and mid-channel areas for all species except Common Eider. This species fed in the mid-channel 48% and in the near shore area off North Lubec 8% of the time, respectively. Common Eiders dive for invertebrate prey such as Blue Mussels (Mytilus edulis) and other invertebrates. Although we saw this species regularly in the study area, the limited diving activity in the deployment area appears to indicate that the deployment area is not a major feeding site for these species. It seems unlikely that there will be substantial interaction between these diving birds and the TidGen Power System. Endangered and Threatened Species: CER surveys did not find any federally or state endangered or threatened species. We did regularly observe Bald Eagles which was removed as a threatened species in 29 (Charles Todd, pers. comm.; MDIF&W). Future Monitoring Schedule Assist MDIFW to count nesting birds on Goose Island, May - June 211. Calendar of expected TidGen Power System installations in Cobscook Bay: October 211: the single-device TidGen Power System is deployed: CER monitoring schedule: - All surveys will be a standard 3-4 hour period. Continue monitoring 1-2 times/month, weather permitting, from present (Aug 211) through expected deployment, Oct 211. During deployment, monitor 2-3 times/week with standard 3-hour surveys to determine potential disturbance of this installation. Continue post-deployment monitoring for 12 months - 1-2 times/month, weather permitting. October 212: four additional TidGen devices are deployed to create a five-device TidGen Power System: During deployment, monitor 2-3 times/week with standard 3-hour surveys to determine potential disturbance of this installation.
Continue post-deployment monitoring for 12 months - 1-2 times/month, weather permitting. Interim Report Schedule Interim report for first winter seabird surveys: Dec 21 - May 211 - due July 211. Interim report for first spring and summer 211 - due October 211. Interim report for deployment monitoring, post-deployment monitoring, and second fall period - due Feb 112. Further reports to be determined. Literature Cited: Birds of North America; Cornell Lab of Ornithology and American Ornithologists s Union. Maine Department of Inland Fisheries and Wildlife. http://www.maine.gov/ifw/wildlife/species/ endangered_species/state_federal_list.htm Holm, K. J., and A. E. Burger. 22. Foraging Behavior and Resource Partitioning by Diving Birds during Winter in Areas of Strong Tidal Currents. Waterbirds 25:312-325. Huettmann, F., A. W. Diamond, B. Dilzell, and K. MacIntosh. 25. Winter distribution, ecology, and movements of Razorbills Alca torda and other auks in the outer Bay of Fundy, Atlantic Canada. marine Ornithology 33:161-171. Larsen, P. F. 24. Introduction to ecosystem modeling in Cobscook Bay, Maine:a boreal, macrotidal estuary. Northeastern Naturalist 11:1-12. Longcore, J. R., and J. P. Gibbs. 1988. Distribution and Numbers of American Black Ducks along the Maine coast during the severe winter of 198-1981. Pages 377-387 in Waterfowl in winter (M. W. Weller, ed.), University of Minnesota Press, Minneapolis. Martin, P., and P. Bateson. 1986. Measuring behaviour: an introductory guide. Cambridge University Press, Cambridge. 14