New data shows that a nearly £1 billion ($1.3bn) investment in fish health and welfare has yielded the best survival rates for farmed Scottish salmon during September since 2020, according to representative body Salmon Scotland.

The association said in a press release that new figures report a 98.18% survival rate for salmon in September, marking a substantial improvement in a month that is historically challenging for fish in sea pens.

"The percentage of fallen stock was around half the rate recorded in September last year when warm sea temperatures in the autumn led to micro jellyfish blooms, which can harm fish," it said.

Salmon Scotland said that this achievement follows a dedicated effort to tackle seasonal challenges, such as warmer autumn sea temperatures and micro jellyfish blooms, which last year caused a marked increase in salmon mortality.

The recent success is attributed to strategic investments in advanced fish health technologies and welfare measures, including freshwater treatment vessels, enhanced monitoring systems, and targeted research.

Scottish salmon farmers, who produce the UK’s largest food export, now report a notable reduction in "fallen stock", with the mortality rate nearly half of what it was in September last year. These improvements have led to higher survival rates throughout 2024, reaching a record 99.03% in June.

"Scottish salmon farmers provide the highest standards anywhere in the world," claimed Tavish Scott, chief executive of Salmon Scotland. "The care our farmers provide means that survival rates for farm-raised salmon -- which spend up to 18 months in the sea -- are dramatically higher than their wild cousins."

The positive trend follows industry-led initiatives such as aeration systems, bubble curtains to block jellyfish, and movement strategies that reduce salmon’s time near harmful organisms.

The sector, which voluntarily publishes monthly survival reports, will soon release its annual production survey for 2023 on Oct. 30.

The survey will highlight the widely reported environmental challenges faced last year, but Salmon Scotland said the situation has markedly improved since then, with production up by 15% in the first half of 2024 to 86,600 metric tons, compared to 75,000t at the same stage of 2023.