SHIPBOARD SURVEYS OF MARINE BIRDS 



Survey Procedures 



Make sure all necessary environmental data (e.g., depth 

 and temperature) and locational data (e.g., positions and 

 speed) will be available and that the bridge personnel know 

 that you are beginning observations. Select the best point 

 on the ship from which you can obtain an unobstructed 

 view of the potential count zone. Set your watch to match 

 your time with that of the ship. Obtain from the bridge 

 the ship's approximate speed and direction. Determine 

 how many instantaneous counts you will need to fill up 

 the transect. Recording begins with all environmental 

 data, such as barometric pressure and sea state, and a 

 determination of the observation conditions. Spend several 

 minutes studying the birds in the immediate vicinity of 

 the ship, noting the general behavior of all birds within 

 the area, and then record the maximum number of each 

 ship-following species on the transect form. Bow-riding 

 porpoises are handled the same as ship followers. Begin 

 the transect by making the first instantaneous count. 



Supplemental Techniques 



Skiff Counts 



Transects can be conducted from skiffs. All birds are 

 counted within a specified distance on both sides of the 

 skiff; 50-75 m on each side is a fairly standard distance 

 if the observer is sitting, and 75-100 m if standing. The 

 area covered by the survey is determined by the distance 

 between a starting and ending position, rather than by 

 speed and time. To obtain accurate positions it is best to 

 conduct transects between known points of land or buoys. 

 Linear distance (in hundreds of meters) should be placed 

 in columns 76-78 of the coding form (Fig. 2). 



Coastline Counts 



Coastline surveys are best conducted from platforms 

 such as skiffs or small ships. The observer should stay 

 as far offshore as possible, while still being able to detect 

 and identify all birds on the water and roosting on shore. 

 All birds between the shore and the platform and from 

 the platform to the limit of visibility on the other side of 

 the platform are counted. On this type of survey, birds 

 on shore can be included by recording them with a "4" 

 in the Zone column. Usually the width of the count area 

 is about 75 m on each side, but it varies with visibility 

 and water conditions. Density estimates are impossible 

 to construct, and the unit of analysis is birds per kilometer 

 of coastline. We recommend using distinct headlands as 



the divisions between counts so counts can be readily 

 repeated. 



Ship-follower Counts 



The only time a ship-following bird is coded as being 

 in a transect is when it joins the ship for the first time 

 (i.e., before it becomes a ship-follower). Otherwise, ship- 

 following birds are not included in density indexes. It is 

 worthwhile, however, to keep a continuous record of their 

 numbers, especially when individual birds cannot be 

 separated. On every transect the observer records the 

 largest number of each ship-following species seen at any 

 one time. Ship-follower counts add to the observer's 

 awareness of what birds are in the area and how the birds 

 are reacting to the ship. In addition, they help an observer 

 determine whether to count birds approaching the ship 

 and whether a sighting represents a new bird or one 

 counted previously. 



Station Counts 



These counts are taken from a fixed point, usually from 

 a ship stopped for oceanographic sampling or fishing. 

 These counts are valuable for determining the numbers 

 of birds that may be dependent on fishing vessels or are 

 vulnerable to pollution from ships. They also provide an 

 excellent opportunity to obtain ratios (e.g., color phases, 

 age, sex, species). The survey area is generally a circle 

 with a 300-600 m radius and the observer at the center. 

 All birds are counted within the count zone by making 

 a circular sweep of the entire area as rapidly as is consis- 

 tent with accurate detection and counting of birds within 

 the area. Only one sweep is made per survey. The length 

 of time the ship has been stationary should be recorded 

 for each survey, because numbers of birds usually con- 

 tinue to increase for a long period after the ship has 

 stopped. The best place to record this information, along 

 with pertinent information on the ship's activity, is in the 

 Field Notes section of the data sheet. Whenever possi- 

 ble, these counts should be repeated every 30 or 60 min. 



General Observations 



Important incidental observations should be recorded 

 and are maintained within the data base. Of particular 

 importance are the location of feeding flocks, large 

 assemblages, and rare species that would not otherwise 

 be recorded. General observations are used: when tran- 

 sects terminate before the designated time; when the ship 

 makes large-scale changes in course or speed during the 



