Climate science may help predict mussel production


Sea temperatures influence mussel production, but the link between the two is not always clear. Sea temperatures have been rising globally with climate change, but temperatures also fluctuate with shorter-term climate variability, along with other factors that influence food supply for the mussels.

A study about climate variability and its links with mussel production is contributing to the development of a tool to help one of New Zealand’s most valuable industries forecast seasonal production.

NIWA Principal Scientist Dr John Zeldis used mussel industry data and NIWA research in a study of mussel production in Pelorus Sound. He found that mussel production fell and then rose back to original levels between 1997 and 2005, in line with various climatic factors which influence mussel food supply. He did this by relating industry data on mussel meat yield with month-to-month climate and ocean data collected by NIWA and the mussel industry.  

Dr Zeldis has not done research on mussel production over longer time periods related to climate change, but shorter-term studies show that it may be possible to predict mussel production in Pelorus Sound over periods from 3 to 6 months into the future. This would use the Southern Oscillation Index, a measure of climate variability which indicates whether the country is in an El Niño or La Niña weather pattern, which in turn modulates local sea temperatures. Other important factors are Pelorus River flow, which supplies nutrients to Pelorus Sound, and wind directions through Cook Strait, which influence “upwelling” – the supply of nutrient-rich water to the entrance of the sound from the deeper ocean.

Dr Zeldis’ report is available at this link:  

Zeldis J, Hadfield M, Booker D (2013). Influence of climate on Pelorus Sound mussel aquaculture yields: correlations and underlying mechanisms.  Aquaculture Environment Interactions. 4:1-15.