Featured Research

from universities, journals, and other organizations

Fish Growth Changes Enhanced By Climate Change

Date:
May 1, 2007
Source:
CSIRO Australia
Summary:
Australian researchers have found correlations between changes in wind patterns and sea temperatures in the southwest Pacific, and fish growth rates.

CSIRO's Dr Ron Thresher with deep-ocean corals used in the study to assess growth rates in fish species.
Credit: Image courtesy of CSIRO Australia

Changes in growth rates in some coastal and long-lived deep-ocean fish species in the south west Pacific are consistent with shifts in wind systems and water temperatures, according to new Australian research.

Related Articles


“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.

“Dr Thresher said slower growth in fishes has been correlated with a variety of life history traits – from higher mortality to reduced food availability and increased age or smaller size at sexual maturity.”

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 examined – Banded morwong, redfish, Jackass Morwong, Spiky, black, smooth and Warty Oreo and Orange roughy. Because of the pervasive effect of temperature on the physiology and growth of marine animals, it was likely that similar effects would be seen in many other species.

The science team examined 555 specimens ranging in age from two to 128 years, with birth years from 1861 to 1993. Growth rates of a coastal species, juvenile morwong, in the 1990s were 28.5 per cent faster than at the beginning of the period under assessment in the mid-1950s. By comparison, juvenile oreos, a species found at depths of around 1,000 metres, were growing 27.9 per cent slower than in the 1860s. There was no or little change in the growth rates of species found between 500 and 1,000 metres.

Growth rates of the juveniles of the deep-water species all began decreasing well before the onset of commercial fishing. Dr Thresher said slower growth in fishes has been correlated with a variety of life history traits – from higher mortality to reduced food availability and increased age or smaller size at sexual maturity.

He said comparisons of historical and modern oceanographic data indicate temperature trends very similar to the apparent changes in growth rates. In the south west Pacific east of Tasmania sea surface temperatures have risen nearly two degrees, based on the results of a monitoring program at Maria Island. Coinciding with this has been a southward shift in South Pacific zonal winds which has strengthened the warm, poleward-flowing East Australian Current.

“Modelling suggests that, with increasing global warming, temperatures at intermediate depths are likely to rise near-globally,” Dr Thresher said. “This could mean that over the course of time, the decrease in growth rates for the deep-water species could slow or even be reversed,” Dr Thresher said.

Article: Depth-mediated reversal of the effects of climate change on long-term growth rates of exploited marine fish, was authored by Dr Thresher, Dr Tony Koslow, now of the Scripps Institute of Oceanography, Dr A.K. Morison, now at the Bureau of Resource Sciences, and Dr David Smith, now of CSIRO.


Story Source:

The above story is based on materials provided by CSIRO Australia. Note: Materials may be edited for content and length.


Cite This Page:

CSIRO Australia. "Fish Growth Changes Enhanced By Climate Change." ScienceDaily. ScienceDaily, 1 May 2007. <www.sciencedaily.com/releases/2007/04/070427120433.htm>.
CSIRO Australia. (2007, May 1). Fish Growth Changes Enhanced By Climate Change. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2007/04/070427120433.htm
CSIRO Australia. "Fish Growth Changes Enhanced By Climate Change." ScienceDaily. www.sciencedaily.com/releases/2007/04/070427120433.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Whale-Watching Scientists Spot Baby Orca

Whale-Watching Scientists Spot Baby Orca

AP (Feb. 28, 2015) Researchers following endangered killer whales spotted a baby orca off the coast of Washington state, the third birth documented this winter but still leaving the population dangerously low. (Feb. 28) Video provided by AP
Powered by NewsLook.com
The Best Drinks for Your Health

The Best Drinks for Your Health

Buzz60 (Feb. 27, 2015) When it comes to health and fitness, there&apos;s lots of talk about what foods to eat, but there are a few liquids that can promote good nutrition. Krystin Goodwin (@krystingoodwin) has the healthiest drinks to boost your health! Video provided by Buzz60
Powered by NewsLook.com
Cherries, Snap Peas and More Tasty Spring Produce

Cherries, Snap Peas and More Tasty Spring Produce

Buzz60 (Feb. 27, 2015) From sweet cherries to sugar snap peas, spring is the peak season for some of the tastiest and healthiest produce. Krystin Goodwin (@Krystingoodwin) has the best seasonal fruits and veggies to spring in to good health! Video provided by Buzz60
Powered by NewsLook.com
The Best Foods to Battle Stress

The Best Foods to Battle Stress

Buzz60 (Feb. 26, 2015) If you&apos;re dealing with anxiety, there are a few foods that can help. Krystin Goodwin (@krystingoodwin) has the best foods to tame stress. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins