There is an increase to the public transportation fares. Tokens that can be used for all ferries, rail systems (metros, trams, local trains, funiculars, etc.) have increased to 3 TL. So each token costs 3 TL. If you are using Istanbulkart, all bus fares have increased to 1.95 TL.
Transfers to ferries within 2 hours of initial usage of Istanbulkart will be 1.40 TL. Ferries and all rail systems will also cost 1.95 TL with Istanbulkart. Now the savings of Istanbulkart have become substantial.
With these increases, Istanbul public transport prices are now approaching the European averages. I recommend everyone staying more than 2-3 days in Istanbul, to get an Istanbulkart.