ACCESS NUMBER: M09PG00004

1

STUDY TITLE: Surveying for Marine Birds in the Northwest Atlantic

REPORT TITLE: Pelagic Seabirds off the East Coast of the United States 2008-2013

CONTRACT NUMBER: M09PG00004

SPONSORING OCS REGION: Environmental Studies Program, Headquarters, Herndon, VA

APPLICABLE PLANNING AREAS: North, Mid-Atlantic

FISCAL YEAR(S) OF PROJECT FUNDING: FY2009; FY2010; FY2011; FY 2012; FY 2013

COMPLETION DATE OF REPORT: June 2015

COSTS: FY09 $139,400; FY10 $278,800; FY11 $130,000; FY12 $130,000: 

CUMULATIVE: $678,200

PROJECT MANAGER: Tim Jones

AFFILIATION (PROJECT MANAGER): US Fish and Wildlife Service, Northeast Region

ADDRESS: 11410 American Holly Drive, Laurel, MD 20708

PRINCIPAL INVESTIGATORS: Richard R. Veit, City University of New York

KEY WORDS: Seabirds, East Coast, surveys, ECOMON, Herring Acoustic Survey, hotspots

BACKGROUND: There is heightened interest in developing wind resources in the offshore 

waters of the Atlantic, and thus there is a need for information on the spatial and temporal 

movement and occupancy patterns of wildlife in offshore habitats. Agencies overseeing offshore 

permitting processes are investing resources in surveys to gather baseline information on the use 

of offshore habitats by wildlife to use for siting offshore developments. Ships of opportunity 

surveys, the results of which are the focus of this report, are one of many ongoing efforts to 

determine areas of significance to marine birds and other marine resources. Communities of 

seabirds inhabiting the pelagic waters off the U.S. East Coast are dominated by wintering 

nonbreeders, mainly shearwaters and storm-petrels that nest on remote islands in the southern

hemisphere. Because the nesting colonies of these birds are not generally accessible, shipboard 

surveys of the ocean are one of the best ways to quantify abundance of these seabirds in our area 

and to measure variability over time.

OBJECTIVES: Our primary objective was to determine current seabird distribution and 

abundance from Maine to Cape Hatteras, North Carolina. A secondary objective was to 

determine whether changes in distribution and abundance have occurred relative to historic 

records. A tertiary objective was to assess whether changes, if they have occurred, might be 

attributed to climate change or fisheries.
ACCESS NUMBER: M09PG00004

2

DESCRIPTION: This report presents the results of 22 research cruises over the shelf waters of 

the eastern United States between August 2008 and February 2013, using NOAA research 

vessels as platforms. The purpose of these surveys was to establish baseline data on the seasonal 

abundance and distribution of pelagic bird species which could be used for determining where to 

site potential offshore development, as well as to draw comparisons with seabird data collected 

in the 1970s and 1980s. Our sampling was limited to the continental shelf, which extends to 

about 100 nautical miles off the northeastern United States.

In 2011, we participated on three NOAA Ecomon cruises between February and November, and 

then a fourth in February 2012. We also collected data on a Herring Acoustic Survey in 

September 2011. In 2012-2013, we collected data on 4 Ecomon cruises between June 2012 and 

February 2013, and a Herring Acoustic Survey in September-October 2012.

All data are stored at the US Geological Survey’s database in Patuxent, Maryland. We collected 

data on seabirds while the ship was underway during daylight hours. We discontinued sampling 

when the ship stopped to sample an oceanographic station. We used a combination of striptransect and line-transects to quantify density. Our default method was to sample a 300 m wide 

strip transect situated on the side of the ship that offered the best visibility. When densities were 

not so high as to overwhelm the observer, we recorded distances and angles to all birds spotted, 

regardless of their distance from the ship (i.e. >> 300m). This ensured our ability to scale data 

collected within the 300 m strip on the basis of detectability of individual species of birds.

SIGNIFICANT CONCLUSIONS: We identified two primary Hotspots of abundance, one off 

southeastern Cape Cod and the other at the mouth of the Chesapeake Bay. These two areas were 

both Hotspots of abundance and species number; there was in addition a diversity hotspot off of 

northern New Jersey and in the New York Harbor area. All these Hotspots were heavily 

influenced by the abundance of sea ducks, terns, gulls and loons. That is, they were close enough 

to shore to record all these species, which do not occur in truly pelagic waters. This suggests that 

we need to recalculate Hotspots so as to be specific to habitats; we need, for example to identify 

what areas are hotspots for shearwaters and petrels, which do not appear in the areas identified as 

Hotspots above, except in small numbers. Apart from this issue, the Hotspots we identified are in 

accord with those identified by marine ornithologists in previous years.

STUDY RESULTS: To compare recent (2008-2011) abundance to that 30 years ago (1975-

1990) we summed bird abundance over the US continental shelf between Maine and Florida, 

with most effort concentrated in the Maryland-Maine sector. We partitioned the dataset to 

include the most heavily sampled areas; we thus used all cells north of 40° and south of 45°. Our 

conclusions about changes in abundance were the same within each partition.

We found that Northern Fulmars and Greater Shearwaters declined by roughly 50% during this 

time interval. These declines are likely due to changes in commercial fishing activity. During the 

late 1970’s, the largest aggregations of seabirds off the eastern U.S. were associated with fleets 

of “factory trawlers” that fished silver hake and other groundfish around the perimeter of 

Georges Bank. These fisheries were effectively excluded by the Magnuson Act in 1978, and the 

supply of discards for seabirds, especially shearwaters, fulmars and gannets, substantially 

declined. Adding to this decline was the collapse of the North Atlantic cod fishery in the 1990s 
ACCESS NUMBER: M09PG00004

3

and the consequent reduction in fishing and discards by the American fleets. These combined 

effects must have resulted in a reduced prey base for pelagic birds, especially those that scavenge 

at trawlers off the U.S, east Coast. Greater Shearwaters breed at Tristan da Cunha in the South 

Atlantic Ocean and Northern Fulmars in the Canadian arctic, and both are very difficult to census 

during the summer; at-sea censuses may be the most reliable indicators of population trends in 

these species (cf. gulls, below).

Gulls, especially Herring and Great Black-backed Gulls, declined by 30-50% in the waters 

surveyed since the 1970s. This decline is in accord with changes noted in the breeding colonies 

in North America. The generally accepted explanation for the recent declines in these gull 

populations is the reduction in garbage available (due to changes in the way garbage is dumped, 

with no “open” dumping) and the reduction in bycatch from trawlers and shore-based fishery 

processing facilities.

Northern Gannets increased in our area by about 30%, which roughly corresponds to increases in 

the Newfoundland and Quebec colonies during the same time period. The reasons for this 

increase are not entirely clear, but are partly related to changes in fish populations and in climate.

Interestingly, a shoreward shift in the distribution of gannets is clearly evident in our 

distributional maps. This indicates a shift from scavenging trawlers near the shelf break in the 

1970s to more coastal foraging. Such a shoreward shift also occurred for Great Black-backed and 

Herring Gulls and is almost certainly caused by the reduction in fisheries effort offshore and 

consequent decrease in availability of discards and offal during the intervening years.

Wintering Razorbills and Dovekies both increased substantially within the US continental shelf 

since the 1970s. Razorbill breeding colonies between Maine and Newfoundland have increased 

during this same time period, in part due to the cessation of gill net fisheries around 

Newfoundland in the early 1990s, but their southward push in winter in recent years is related to 

North Atlantic Oscillation. they move further south in NAO positive years. Dovekies nesting in 

underground burrows in the high arctic are almost impossible to census, but their numbers off the 

eastern USA have increased very dramatically since about 2000, and this increase is at least 

partly related to a series of strongly NAO-negative years.

STUDY PRODUCTS: 

Viet, R.R, H.F. Goyert, T.P. White, M.-C. Martin, L.L. Manne, and A. Gilbert. 2015. Pelagic 

Seabirds off the East Coast of the United States 2008-2013. US Dept. of the Interior, Bureau of 

Ocean Energy Management, Office of Renewable Energy Programs, Sterling, VA. OCS Study 

BOEM 2015-024. 186 pp.