“We have drawn correlations between the growth of fish species related to their environmental conditions ?faster growth in waters above a depth of 250 metres and slower rates of growth below 1,000 metres,?says lead author, Dr Ron Thresher.
“These observations suggest that global climate change has enhanced some elements of productivity of shallow-water stocks but at the same time reduced the productivity and possibly the resilience of deep water stocks,?he says.
A biological oceanographer with CSIRO’s Wealth from Oceans Research Flagship, Dr Thresher said the research ?published in the latest edition of the US science journal, Proceedings of the National Academy of Sciences ?is based on the examination of fish earbones, or otoliths, which show similar characteristics to the growth rings used to date the age of trees. The work was done in collaboration with the Victorian Marine and Aquatic Fisheries Research Institute, which has specialist skills in analysing otoliths.
Water temperatures have been obtained from a 60-year-long record at Maria Island on the Tasmanian east coast, and using 400-year-old deep-ocean corals to measure temperate at depth.
Dr Thresher said populations of large marine species are widely subject to two major stressors ?commercial fishing and climate change. Heavy exploitation increases the sensitivity of species to environmental effects and could be magnifying the effects of long-term climate change and short-term climate variability on the viability of some species.
He said correlations for long-lived shallow and deep-water species suggest that water temperatures have been a primary factor in determining juvenile growth rates in the species