As of 2014, those flights have been done three times a year - in January, April and August.
Each year, the January count has been much higher than the August count. In 2014, when swan numbers peaked, it was around 6400 in January, 4000 in April and 400 in August.
Mr Garrick said 90 per cent of the swan population appeared to leave the harbour in winter.
Where they go, why, and which swans remained were all questions research might clarify.
As well, research into what the swans eat, how much and what they expelled could help measure the net effect on important ecological features of the harbour such as eelgrass (Zostera beds), he said.
One overall goal was to determine the size of the swan population the harbour could support without adverse effects.
"We acknowledge that there is more science needed around this. We don't want to do anything based on emotion."
Eastern Fish & Game was eager to not to repeat 2013's sanctioned but perhaps "hasty" swan cull, which prompted outrage in the community.
In any case, periodic reports of flocks with birds numbering in the "tens of thousands" on the harbour were "nonsense" and not supported by data, Mr Garrick said.
A Bay of Plenty Regional Council spokesman said the council was discussing swan management with Eastern Fish & Game and the Department of Conservation.
"We are also monitoring swans and researching their effects on the harbour."
Earlier this week, regular users of the beach at Pahoia Domain raised concerns about the amount of swan poo in the area.
Swan numbers on Tauranga Harbour
- 6400 - Highest number of black swans recorded on Tauranga Harbour, January 2014
- 4600 - Average January swan count over 10 years
- 6200 - January 2017 swan count
- 2500 - April 2017 swan count
- 1991 - When Fish & Game started doing aerial counts of the harbour's swans