2 The Aerial Sightings Database
2.1 Data sources
The aer_sight database contains records of search effort and
sightings of pelagic schooling species (mainly skipjack tuna,
kahawai, blue mackerel, jack mackerel and trevally) from pilots
spotting fish schools for purse-seiners around New Zealand. Aerial
sightings data are not collected according to experimental design.
They are captured opportunistically by pilots of light aircraft
employed as fish spotters in purse-seining operations. The majority
of effort is centred in the Bay of Plenty (BOP), Golden and Tasman
Bays, the Kaikoura coast and to a lesser extent, the South Taranaki
coast. The time series of these data begins in June 1976, and is
2.2 Data validation
While the aer_sight database enforces data validation and
integrity rules with the use of referential constraints and range
checks, data go though rigorous data validation and error checking
process before being entered.
This process includes instructions for data recording, simple data
validation using the checkq2 validation program language and C
programming language scripts. See Appendix 1 for a more detailed
description of the processes involved.
2.3 Uses of the aerial sightings database
Aerial sightings data can be used for a range of outputs, from
profiles of pelagic species distribution and purse-seine activity to
providing background information on stock assessments of these
species (Taylor in preparation). Probably the most important output
is time series of relative abundance which can indicate fluctuations
in their abundance from year to year (Bradford & Taylor 1995).
Commercial and recreational interests request various types of data
reports several times a year.