Lerwick harbour saw a large rise in cargo tonnage in the first half of 2014 but vessel numbers fell by 11%.
Bosses said yesterday the year-on-year drop in the number of boats, to 2,230, was mainly due to a decline in fishing-related visits.
According to Lerwick Port Authority (LPA), this was also reflected in a decrease in white-fish landings – hit by bad weather in the early part of the year – as well as fewer vessel refits and the number of boats on charter to the oil industry.
The total weight of cargo handled by the port jumped by 8% to 582,253 tonnes, while total ferry and cruise passenger numbers increased by nearly 14% to 78,894.
Total vessel tonnage was down by 10% at 5.5million gross weight, which LPA said was mainly due to an expected decrease in the number of visiting bulk carriers/pipe-burying ships carrying out oil and gas industry work.
LPA chief executive Sandra Laurenson said: “The nature of offshore projects means that the scale and type of traffic fluctuate.
“The reduced ship tonnages were forecast and are partially offset by the long-term presence of a significant tonnage of accommodation vessels housing construction workers at the Shetland gas plant.
“The deep-water port continues to be busy supporting major development and decommissioning projects.”
She added: “The sustained high level of other offshore activity and increased cargo and passenger figures are all positives.
“There was a welcome boost to winter mackerel landings at the start of the year, although the autumn fishery may be more modest due to poor international markets.”
First half fish landings were up 25% by volume and 35% by value, totalling 37,091 tonnes worth £35.1million.