Please select your home edition
Edition
Naiad

Commercial fishing, climate change causing fish to shrink

by CSIRO on 5 Feb 2013
Silver Warehou ..
A new study by Australia's peak scientific body the CSIRO shows that fish around the world are shrinking in size.
Commercial fishing and climate change are believed to be the main culprits behind the decrease, but CSIRO scientists say the shrinking size is also leading to a drop in fish populations, with smaller fish more susceptible to predators.


Marine biologist, Dr Asta Audzijonyte of the CSIRO's Wealth from Oceans Flagship, and colleagues, reported their findings in the journal Royal Society Biology Letters.

Dr Audzijonyte says commercial fishing could be changing the long-term evolution of fish sizes.

She found that even small decreases in the body size of some fish species had a big impact on their population size, because it made fish more vulnerable to predators.

'So basically, if the flathead gets a bit smaller, it's being eaten more heavily by other fishes like barracuda, which is the predator of the flathead,' she explained.
The CSIRO study looked at five Australian fish species: Tiger flatheads, jackass morwong, silver warehou, blue grenadier and pink ling.

'We usually selectively catch the largest and the fastest-growing individuals, leaving the small ones in the ocean. So we only have the small ones left ... But then also, only the small ones get a chance to reproduce, and they are more likely to produce other small and slow-growing fish.

'So in this way, we are getting a long-term evolutionary decline in body size, which is more problematic because the fish will not get bigger quickly, even if we completely stop fishing, because they already became evolutionarily smaller.'

The scientists used a complex modelling system to test how the decreasing fish size affects the interactions between different species.

More at http://www.csiro.au/en/Organisation-Structure/Divisions/Marine--Atmospheric-Research.aspx
Beneteau PWR ST30 660x82 1Barz Optics - Kids rangeNaiad

Related Articles

Yamaha voted most trusted marine engine brand 2017!
Yamaha Motor New Zealand takes top spot as New Zealand’s Most Trusted Marine Engine Brand for 2017! The results of the Reader’s Digest annual Most Trusted Brands Survey are out, and for the first time ever includes a Marine engine category, with Yamaha Motor New Zealand taking top spot as New Zealand’s Most Trusted Marine Engine Brand for 2017!
Posted today at 5:32 am
Reef Summit sets new course of action for the Great Barrier Reef
A blueprint to respond to coral bleaching and other recent impacts on Great Barrier Reef was focus of Reef Summit A blueprint to respond to coral bleaching and other recent impacts on the Great Barrier Reef was the focus of this week’s two-day Reef Summit in Townsville, Australia. Hosted by the Great Barrier Reef Marine Park Authority, the summit — Managing for resilience— was the first of its kind for the Reef and involved more than 70 leading marine experts from around the world.
Posted on 26 May
Evinrude Sponsors Chain of Records 2017
BRP announced today that Evinrude sponsored Chain of Records 2017 event held April 18-23 in Polk County, Florida BRP, a world leader in powersports, announced today that Evinrude sponsored the Chain of Records 2017 event held April 18-23, on multiple lakes in Polk County, Florida. Organized with over a year of planning to break national and world records in water skiing, the event resulted in more than 36 records being broken, including the Most Records Broken at a Single Event.
Posted on 26 May
ASMEX Conference – Day 1
Around 260 international and local industry experts gathered in Sanctuary Cove for the seventh Australian Superyacht Richard Chapman, president of AIMEX, opened the event on Monday by referencing the Australian Superyacht Industry Economic Impact Study and its findings that the industry contributes A$1.96bn to the Australian economy.
Posted on 25 May
Brooker Marine and BlueFin Boats announce the merger
The Directors of Brooker Marine and BlueFin Boats wish to announce the merger of two Australian manufacturing operations The Directors, Shareholders and Management of Brooker Marine and BlueFin Boats wish to announce the merger of the two highly respected Australian manufacturing operations.
Posted on 25 May
Simrad launches new AP48 Autopilot Controller
Announcing new Simrad AP48 Autopilot Controller — premium dedicated control head for Simrad Continuum autopilot systems Announcing the new Simrad AP48 Autopilot Controller — a premium dedicated control head for Simrad Continuum autopilot systems, featuring an optically bonded 4.1-inch full colour display and modern glass-helm styling.
Posted on 25 May
Old4New Van notches up 100,000km and 20,000 lifejackets
Minister for Roads Maritime and Freight Melinda Pavey today announced the Old4New life jacket programme Minister for Roads Maritime and Freight Melinda Pavey today announced the Old4New life jacket programme had exchanged more than 20,000 old lifejackets for new ones, spreading the ‘wear a lifejacket’ message.
Posted on 23 May
High water on the great lakes – Boom or bust for boaters?
Boaters can find that deeper water under the keel may open a range of cruising, fishing or sailing grounds to navigation With Great Lakes water levels on the rise and expected to continue to increase into summer, recreational boaters could find that deeper water under the keel may open a whole new range of cruising, fishing or sailing grounds to navigation.
Posted on 19 May
Simrad launches new NAIS500 Class-B AIS
Announcing a fully integrated, Class-B Automatic Identification System (AIS) transponder – the Simrad NAIS 500. Announcing a fully integrated, Class-B Automatic Identification System (AIS) transponder – the Simrad NAIS 500. Essential for navigating busy shipping lanes and congested ports, the NAIS 500 — which includes a dedicated GPS-500 receiver — is compact in size, lightweight and fully waterproof. It offers low power draw and features multiple connections for networking with any NSS, NSO
Posted on 18 May
Maritimo sees future growth through Silver Seas Yachts
Maritimo CEO Garth Corbitt said SSY would be representing Maritimo throughout Northern California and Pacific Northwest. As part of the ongoing expansion of its international dealer partner network Australian luxury motor yacht manufacturer Maritimo has partnered with one of the USA's most respected dealers, Silver Seas Yachts.
Posted on 8 May