Cape Breton Beached Bird Survey 2001/2002 Winter Report

Transcription

1 Cape Breton Beached Bird Survey 2001/2002 Winter Report May 28, 2002 Mike Russell Bird Studies Canada Atlantic Region P.O. Box Waterfowl Lane Sackville, NB E4L 1G6 Phone (506) Fax (506) becky.whittam@ec.gc.ca

2 Introduction: The Atlantic Canadian coast supports a large amount of transatlantic shipping traffic. This traffic means that there will be both major and minor spills of petroleum products on occasion, as well as chronic petroleum pollution. Oil pollution poses a great threat to pelagic seabirds (birds that spend most of their non-breeding season in the open ocean feeding on or under the water), because the physical properties of oil degrade the insulating and waterproofing properties of feathers. Ingestion or inhalation of oil can also poison birds internally. Oil pollution often proves fatal to seabirds in the harsh Atlantic waters, especially in winter when air and water temperatures are colder and birds are more vulnerable to exposure. In fact, at this time of year, a spot of oil an inch in diameter on the belly of a bird is sufficient to kill it. Dead and dying birds tend to wash up on beaches. By monitoring birds on beaches, and keeping track of whether or not they have been affected by oil pollution, we can detect fluctuations in both the amount of oil pollution occurring in the Atlantic, as well as its effect on waterbirds. Cape Breton has been identified as an area of extreme risk for birds oiled at sea, due to both the heavy shipping traffic through the Cabot Strait and the concentrations of marine birds that use this water in winter. The beached bird survey will serve to develop a baseline index of oiled birds in Cape Breton. If large spills occur, this baseline can be used to estimate the impact of the spills on seabirds. Beached bird survey data can also be used to determine what species of seabirds are most affected by oiling, what time of year the problem is most severe, and whether the proportion of oiled birds washing up on beaches is changing over time. A beached bird survey has been in place in southeastern Newfoundland since Results of this survey indicate that the proportion of beached birds that are oiled has been increasing steadily, at a rate of 3% per year, since the survey began. While this may be due to a decrease in clean dead birds (due to declining murre hunts and milder weather conditions in winter) there is still a clear relationship between ship traffic volume and the proportion of oiled birds. Therefore, there is clearly a great need to monitor beached birds on Canada s Atlantic coast. The objectives of this project for the first 6 months were to: 1) Develop a protocol for a beached bird survey in Cape Breton, NS; 2) Recruit volunteers to survey beaches from November-April 3) Enter the resulting data into a beached bird survey database In this report we present the results of the first year of the Cape Breton Beached Bird Survey. The results are necessarily simple given that no trends can be calculated until several years of data have been collected. Methods: Beach Selection: Segments of beach were selected to be surveyed at the volunteers discretion based on the projected potential for detecting beached birds, the projected accessibility of the beach in the winter months and general convenience to the volunteer. Many of the beaches surveyed were areas that the volunteers walked on a regular basis in addition to the survey. Beach Description: Permanent beach characteristics were recorded and described by the volunteers during their first survey. For universal congruency, this descriptive assessment of beach characters was closely modeled following SCAT (Shoreline Cleanup and Assessment Team) guidelines. Characteristics Cape Breton Beached Bird Survey 2 Bird Studies Canada

3 recorded include a description of both the start and end points directions to the beach, projected accessibility in the winter, backshore type, shoreline classification, and the dominant slope of the beach (map characters were drawn on a topographic map for future reference and coordinate extrapolation). Survey Protocol: The survey protocol is similar to the Newfoundland CWS Beached Bird Survey but also incorporated elements from many other parallel programs (especially that of the Coastal Observation And Seabird Survey Team, or COASST). Volunteers were instructed to survey their beach segment at least once every month from October to November at the end of the month. Volunteers were encouraged to conduct their surveys at low tide, or just after high tide when the tide is receding. Surveyors recorded general weather/beach conditions at the start and end of their beach. These conditions included weather conditions (cloud cover, precipitation, sea state, tide, and wind direction) and beach conditions (wrack thickness and continuity, average driftwood log diameter, continuity and position of the driftwood line, extent of ice, and oil pollution). When beached birds were found, volunteers were instructed to complete an additional data form, tag the carcass if possible and leave the remains to facilitate the collection of persistence data. On the beached bird data form a number of data were recorded. If the carcass was a new occurrence then a unique tag number was attached to the beached bird. If the bird had been tagged on a previous survey, the tag number was recorded and the bird was classified as a refind. This information will allow us to calculate the persistence of birds on beaches from survey to survey. Volunteers were asked to identify the bird to the most specific taxonomic level possible (species, family etc.) given the state of decomposition and the volunteer skill level. The most important detail of this survey was to record the presence, or absence, of oiling on each carcass using the scale directly modeled after the Newfoundland surveys (see appendix A for the oiling codes). In addition, volunteers were asked to record the degree of emaciation of each bird, and the presence/absence of entanglements, sex and age-class, and the suspected cause of mortality if possible. Any live, oiled birds that were present in the immediate area of the survey beach were also recorded on this data form. Results: From November 2001 to April 2002 a total of 19 beaches were surveyed at least once by one of 14 primary volunteers. In total, 61 surveys were completed with a total of more than 84.3 hours of volunteer effort. Eight of these beaches (42%) were run at least 4 times during this 6 month survey period, and 12 of these beaches were run at least 3 times (63%). Many of these surveys were not completed due to the inaccessibility of the beaches during unfavorable winter weather conditions. Figure 1 shows the number of surveys completed per month. Nine of the beaches (47%) surveyed detected at least one beached bird during the 6 month survey period. In total 29 beached birds were detected. Of these, 25 displayed signs of oiling (86%). Of the 29 beached birds recorded; 23 were Murres (12 Thick-billed, 8 Common, 3 General), 3 were Gulls and 3 were unidentifiable. In addition to the beached birds, 10 live oiled birds were observed but not recovered on a later survey. Figure 2 shows the number of beached birds found per month. Figures 3 and 4 show the total number of birds, and the average number of birds per survey, that were detected on each survey beach from November 2001-June 2002 (maps contain data from May & June as well as November-April because they were created after the initial version of this report was complete). Cape Breton Beached Bird Survey 3 Bird Studies Canada

4 Number of Surveys November December January Febuary March April Figure 1 The total number of beached bird surveys completed in each month. 16 Number of beached birds November December January Febuary March April Figure 2 The total number of beached birds found in each month (does not include refinds). Cape Breton Beached Bird Survey 4 Bird Studies Canada

5 Figure 3. The total number of beached birds found at each survey beach from November June Cape Breton Beached Bird Survey 5 Bird Studies Canada

6 Figure 4. The average number of beached birds found per survey at each survey beach from November 2001-June Cape Breton Beached Bird Survey 6 Bird Studies Canada

7 Table 1 Volunteer effort (hours spent surveying), survey frequency, beached bird frequency and the number of beached birds for all beaches for which data were received from November 2001 to April Surveyor Name Beach Number/Name Total Hours # Surveys Completed Beached Birds Oiled Birds Live Oiled Birds Kevin Middel 3/ Pt. Michaud 4.97* George Crowell 4/ Schooner Pond George Crowell 5/ Port Morien Joan Mills 6/ Gabarus 5.00* Susann Myers 7A/ Kennington Cove LeeAnne Reeves 7B/ White Point Susann Myers 7C/ Wild Cove Susann Myers 7D/ Mira Gut Beach Terry Laffin 9/ Florence Sharon & George Digout 11/ Pondville George Delaney 17/ La Bloc, CBHNP Sheldon Lambert 19/ South Habour Sheldon Lambert 20/ Neil's Harbour Sheldon Lambert 21/ Black Brook Erich Muntz 22/ Broad Cove Bethsheila Kent 24/ Englishtown Shawn Sanson 26/ Southeast Bar Vivian and John Pye 27/ Florence Back Beach Ed Barrington 29/ Point Edward Beach Cumulative Total 84.3* *More survey hours were completed, but not recorded on data sheet Discussion: Goal#1: Develop a protocol for a beached bird survey in Cape Breton, NS A protocol was successfully devised using protocols and suggestions from a wide range of current and past beached bird surveys. This incorporation of existing allowed for maximum congruency between the data from other surveys (especially Newfoundland s). Goal#2: Recruit volunteers to survey beaches from November-April Nineteen volunteers were recruited, but survey data was received from only 14 of these volunteers. Thirty beaches were assigned but only 19 were surveyed. Of these 19 beaches, only 8 were surveyed at least 4 times within the 6 month period. Next year it is suggested that there be an increase in volunteer recruitment and attempt to increase survey frequencies from month to month, and decrease turnover from year-to-year. The rate of oiling, shown in Figure 2, at first appears quite dramatic for what was expected along the Cape Breton shoreline. When the survey period is broken down into monthly periods, it is evident that there was an increased volunteer effort during February and March (Figure 1). This is because we asked volunteers to conduct extra surveys, if possible, during this period as a result Cape Breton Beached Bird Survey 7 Bird Studies Canada

8 of an oil tanker spill that occurred off the east coast of Cape Breton in late February. However, this increased survey effort does not appear to be proportional to the steep increase in the frequency of beached birds (Figure 2). Also as a result of the oil spill in late February, Environment Canada staff collected beached bird carcasses for lab analysis. Many of these birds were probably not recorded by BSC s beached bird surveyors. Furthermore, the removal of birds from beaches limits our ability to collect beached bird persistence data. Therefore, in the future, BSC and Environment Canada will attempt to coordinate their efforts in the event of an oil spill in a region where beached bird surveys are occurring. Goal#3: Enter the resulting data into a beached bird survey database A beached bird database was created in Filemaker Pro to allow for the prompt and easy entry of all received beached bird data upon its arrival. This database is currently up-to-date and includes all of the winter survey data. Some suggestions for the upcoming year: 1) Increase volunteer recruitment, attempt to increase survey frequencies from month to month, and decrease turnover from year-to-year; 2) Attempt to collaborate more closely with surveys conducted by Environment Canada staff in the event of an oil spill (to try to establish a network of data sharing and to boost the effectiveness of persistence surveys) ; 3) Extend the survey scope to mainland NS, NB, and PEI; 4) Include a data box on the survey form to allow volunteers to categorically record the reliability of the survey (liklihood of detecting a beached bird if one was present). Acknowledgements The CB-BBS is funded by the Canadian Wildlife Service (Environment Canada- Atlantic Region). Thanks to COASST and the Newfoundland Beached Bird Survey for allowing us to use various aspects of their protocols, instruction booklets and data sheets. Sheldon Lambert of Cape Breton Highlands National Park coordinated volunteers in the park and created the maps used in this document, and Susann Myers was instrumental in coordinating volunteers outside the park. Thanks to Sinclair Dewis, Francis Wiese, Pierre Ryan, Tony Lock, and Todd Hass whose communications and insight helped to guide the development of this survey. Finally, thanks to all of the volunteers for their dedicated beach-combing during the least pleasant months of the year! Appendix A The codes for the classification of oiling of beached birds (modeled after the Newfoundland surveys): 0) no oil 1) slightly oiled- smudges of oil that do not totally penetrate the breast feathers or coat the wings 2) moderately oiled- oil penetrates to the base of feathers or saturates the wings; <25% of the body is affected 3) heavily oiled- oil penetrates to the base of the feathers, > 25% of the body is affected 4) unable to determine- this should be used if there is less than half of the plumage remaining. If a carcass is coded level 4, volunteers inspect what plumage remains to determine if there is any oil present (recorded as yes for oil present, and no for no oil present). Cape Breton Beached Bird Survey 8 Bird Studies Canada