, I]

ACCESS NUMBER: 14407.1

STUDY TITLE: Monitoring Seabird Populations in Areas of Oil and Gas Development on the Alaskan

Continental Shelf.

REPORT TITLE: A Computerized Pelagic Seabird Atlas for Alaska

CONTRACT NUMBER: MMS 2000-072

SPONSORING OCS REGION: Gulf of Alaska

APPLICABLE PLANNING AREA: Cook Inlet and Kodiak

FtSCAL YEAR OF PROJECT FUNDING: 1993

COMPLETION DATE OF REPORT: 2000

COST: FY 1993: $24,750

PROJECT MANAGER: John Piatt

AFFILIATION: Alaska Biological Science Center, USGS

ADDRESS: 1011 E. Tudor Rd., Anchorage, AK 99503

PRINCIPAL INVESTIGATOR: John p,iatt

KEY WORDS: seabird, Gulf of Alaska, Cook Inlet, Bering Sea, Aleutians, pelagic distribution, mapping,

GIS, atlas, OCSEAP

BACKGROUND: The need for comprehensive geographic data on the pelagic and colony distribution of

seabirds in Alaska has long been recognized. During the Outer Continental Shelf Environmental

Assessment Program (OCSEAP) of the 1970's, unprecedented efforts were undertaken to gather and

assimilate these data..This work culminated in two atlases which are stili widely used today by

researchers and management agencies around the world (despite being out of date). The "Catalog of

Ataskan Seabird Colonies" (Sowls et al. 1978) documented the distribution and species composition of all

seabird colonies in Alaska. Shortly thereafter, Gould et al. (1982) published the atlas of "Pelagic

Distribution and Abundance of Seabirds in the Gulf of Alaska and Eastern Bering Sea" which documented

the at-sea distribution and abundance of 16 common seabird species in one degree latitude- longitude

blocks. In addition to this landmark work, reports by other key investigators laid the foundation for our

understanding of the pelagic biology and distribution of seabirds in Alaska. Since these atlases were

produced, a considerable amount of new data has been collected on the pelagic distribution of seabirds in

Alaska and the North Central Pacific. We proposed to develop a computerized GIS mapping system for

displaying and analyzing pelagic seabird data in Alaska and other areas of the North Pacific. For this pilot

work, we re-compiied the original OCSEAP data from sources at the Fish and Wildlife Service and

National Ocean Data Center, proofed these original data, and archived them in a standard format. A

program was written to compile these data into one degree latitude- longitude blocks, and this database

was used to produce GIS maps using CAMRIS (Computer Aided Mapping and Resource Inventory

System).

OBJECTIVES: (1) Compile original OCSEAP data on the pelagic distribution of seabirds in Alaska from

sources at FWS and NODC; (2) Proof these data and archive them into a common format; (3) Generate

preliminary distribution maps of common seabirds of Alaska using the OCSEAP data in order to

demonstrate the capabilities of a computerized pelagic database.
',' "

ACCESS NUMBER: 14407.I

DESCRIPTION: We began developmenfof a computerized GIS mapping system for displaying and

analyzing pelagic seabird data in Alaska and other areas of the North Pacific. The original atlas by Gould

et al. included about 5,500 shipboard and 1,900 aerial transects conducted in Alaska mostly between

1976 and 1981. For this pilot work, we re-compiled and proofed OCSEAP data collected between 1976

and 1984 and archived 'them in a standard format. About 60,000 transects containing 325,000 records

were documented, comprising observations of more than 4 million animals. A program was written to

further compile these data into one degree latitude- longitude blocks, and this database was used to

produce GIS maps using CAMRIS (Computer Aided Mapping and Resource Inventory System). Density

polygons were generated from blocked data, and missing blocks were filled using algorithms that

extrapolate from densities of adjacent blocks. Maps of murre distribution were drawn to illustrate how the

database can be queried to compile seasonal data, and to generate maps at different spatial scales. Maps

were also drawn for summer months showing the distribution of all other common seabirds in Alaska.

SIGNIFICANT CONCLUSIONS: The computerized pelagic seabird database and atlas could be a

valuable tool for scientists and resource managers. We estimate that it will require about two years of

development to reach a stage where it can be distributed (With associated software) for general

application. It can thEm be used to: i) interpret and improve our understanding of the pelagic ecology of

individual seabird species in the North Pacific, ii) provide distibution and abundance infonmation for

mitigating and assessing impacts of offshore oil development on the Alaskan continental shelf, iii) develop

site-specific information for agencies to provide on request from the public or other management agencies

(e.g., NMFS), and, iv) provide baseline information for assessing changes in seabird distribution and

abundance in the future (particularly where data have been collected systematically and repeatedly in the

same geographic areas).

STUDY RESULTS: Preliminary analyses of pelagic seabird data gathered from ships and compiled for the

years 1976-1984 show how pelagic seabird distribution data can be used to assess gross patterns of

abundance and relationships with topographical features of the region and seabird colony distribution. For

example, murres are concentrated near breeding colonies in summer, and occur mostly within the

boundaries of the continental shelves. Highest densities occur in the Bering and Chukchi Seas. During

winter, murres move south and reside in the southern Bering Sea and southeast Alaska. In Cook Inlet

and along the Alaska Peninsula, murres are concentrated near major breeding colonies at the Semidi

Islands, and in :Iower Cook Inlet. During winter the association with colonies disappears, and murres

concentrate around Kodiak Islands and in Shelikof Strait. The summer distribution of all major seabird taxa

are illustrated. In general, breeding species are most abundant during summer around their breeding

colonies. Species (e.g., fulmars, storm-petrels) that forage at great distances from colonies, however, are

not concentrated near colonies. Non-breeding species (e.g., albatrosses, shearwaters) are not

constrained by colony location and are distributed in habitats preferred for foraging. In any case, mapping

reveals that species exhibit markedly different distributional patterns, often in association with bathymetric

features (e.g., coastal- gulls; shelf- murres, kittiwakes; shelfedge- fulmars, storm-petrels; oceanicalbatrosses).

STUDY PRODUCT: Piatt, J.F. and R.G. Ford. 2000. A computerized pelagic seabird atlas for Alaska.

Final Report for Minerals Management Service (OCS Study MMS 2000-0072). Anchorage, Alaska.

\
..

,

' ..

ACCESS NUMBER: 14407.1 •

i 72 00

~.

i

MURRE Speci~8 I I

JAN-DEC I I l"u·~..o°2003004-00500600 11,

Kil",nctcrs ~,.i .•:....••.'

0.0 Birds/km2 • _-

0-2.8 lJirds/km2

2.1:l-7.7 Bil-ds/km 2

''17.7-21 Birds/ktn2

I!lI! 21-59 Birds/km~ I·':.... 1159-165 Birds/krn2 _

.... 200 n1 contOUI'

Al ask a: II

-II

II

-144 00 136 ".00 /.

..

..

152.00,

.'--.

'~".

Gulf of

.,. -,'

.150 00

;t

I(D~:,~J..... l~···_--,,:"_':::

li~:;Ale uti an

IrA

!II 176 00

Figure 1. Map of che distribution and abundance of murres

(Uria spp.) in Alaska throughout the year. Each 1" latitudelongitude block is Shaded to show the average density of

murres (see key) in t~at block. s~aded blocks reveal where

ship-based pelagic seabird sUt'VE!yshave been conducted during

the time period included for this preliminary analysis (1976-

1984) .