Friday, December 29, 2006
Butterflyfish Decline with Coral
Australian scientists have found evidence that climate change may play havoc with fish populations.
Researchers from the ARC Centre of Excellence for Coral Reef Studies (CoECRS) have tracked a dramatic decline in the numbers of coral-feeding fish, after a reef was destroyed by bleaching caused by high sea temperatures.
Dr Morgan Pratchett, a senior research fellow at CoECRS, and colleagues spent five years charting a collapse in numbers of coral-feeding butterflyfish on reefs affected by severe coral bleaching.
“The evidence suggests that climate change is already hitting certain fish populations – and this could have an adverse effect on industries like tourism,” he warns. “People come to the reef expecting to see colourful fishes.”
“The impact of coral bleaching is most obvious in fish which feed specifically on corals, as do most butterflyfishes. It is not yet clear what knock-on effects this may have on populations of mixed feeders or predatory fish like coral trout - and hence on the fishing industry or recreational angling.”
Their research results indicate that the impacts of coral bleaching can be more far-reaching and last longer than previously thought.
Dr Pratchett said the researchers had also noted a steady decline in body condition of the coral-dependent butterflyfish at Trunk reef on the Central Great Barrier Reef following bleaching events in 2000-2002.
This suggested that the fish were gradually starving to death and the decline in numbers indicated they had also failed to breed in the months and years following the destruction of their reef.
“It looks as if they didn’t move elsewhere, but stayed where they were and starved. Fish can be very territorial and it may be hard for refugee fish which have lost their reef to relocate elsewhere, because the locals will try to keep them out.”
Coral bleaching is caused by high water temperatures which cause the corals to shed their symbiotic bacteria and die. Bleaching events have been noted worldwide and appear to be on the increase as the earth warms, leading to accelerated degradation of reefs.
There have been several major bleaching events affecting corals along Australia’s Great Barrier Reef in recent years, the worst being in 2002, Dr Pratchett said.
More than 30% of coral reefs throughout the world are already severely degraded and corals on 60% may be lost by 2030 due significantly to bleaching as the climate warms, research by CoECRS scientists indicates.
“Ours and other studies indicate that when coral bleaching occurs affecting up to 10 per cent of the reef, it affects the abundance of nearly two thirds of the fish species on that reef.
“As the damage rises to 20 per cent and above, there is a marked decline in the richness of fish species on the reef – and the losses can last for years.
“However we are also confident that, if the corals recover, the coral-feeding fishes will come back,” Dr Pratchett says. “That’s the encouraging news for managers, tourism operators and visitors alike.”
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Researchers from the ARC Centre of Excellence for Coral Reef Studies (CoECRS) have tracked a dramatic decline in the numbers of coral-feeding fish, after a reef was destroyed by bleaching caused by high sea temperatures.
Dr Morgan Pratchett, a senior research fellow at CoECRS, and colleagues spent five years charting a collapse in numbers of coral-feeding butterflyfish on reefs affected by severe coral bleaching.
“The evidence suggests that climate change is already hitting certain fish populations – and this could have an adverse effect on industries like tourism,” he warns. “People come to the reef expecting to see colourful fishes.”
“The impact of coral bleaching is most obvious in fish which feed specifically on corals, as do most butterflyfishes. It is not yet clear what knock-on effects this may have on populations of mixed feeders or predatory fish like coral trout - and hence on the fishing industry or recreational angling.”
Their research results indicate that the impacts of coral bleaching can be more far-reaching and last longer than previously thought.
Dr Pratchett said the researchers had also noted a steady decline in body condition of the coral-dependent butterflyfish at Trunk reef on the Central Great Barrier Reef following bleaching events in 2000-2002.
This suggested that the fish were gradually starving to death and the decline in numbers indicated they had also failed to breed in the months and years following the destruction of their reef.
“It looks as if they didn’t move elsewhere, but stayed where they were and starved. Fish can be very territorial and it may be hard for refugee fish which have lost their reef to relocate elsewhere, because the locals will try to keep them out.”
Coral bleaching is caused by high water temperatures which cause the corals to shed their symbiotic bacteria and die. Bleaching events have been noted worldwide and appear to be on the increase as the earth warms, leading to accelerated degradation of reefs.
There have been several major bleaching events affecting corals along Australia’s Great Barrier Reef in recent years, the worst being in 2002, Dr Pratchett said.
More than 30% of coral reefs throughout the world are already severely degraded and corals on 60% may be lost by 2030 due significantly to bleaching as the climate warms, research by CoECRS scientists indicates.
“Ours and other studies indicate that when coral bleaching occurs affecting up to 10 per cent of the reef, it affects the abundance of nearly two thirds of the fish species on that reef.
“As the damage rises to 20 per cent and above, there is a marked decline in the richness of fish species on the reef – and the losses can last for years.
“However we are also confident that, if the corals recover, the coral-feeding fishes will come back,” Dr Pratchett says. “That’s the encouraging news for managers, tourism operators and visitors alike.”
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Labels: coral, environment, sealife
Wednesday, December 27, 2006
Lawsuit Filed to Protect World's Most Endangered Whale
The Center for Biological Diversity has filed a lawsuit to compel the Bush administration to protect the North Pacific Right Whale under the federal Endangered Species Act. The US Department of the Interior has proposed opening up areas in the Bering Sea frequented by the species to offshore oil development. Additionally, President Bush is considering lifting the presidential withdrawal that currently prohibits such development.
The North Pacific Right Whale (Eubalaena japonica), once ranging from Baja California to Alaska, is the most endangered large whale in the world, with perhaps as few as 100 individuals remaining. Devastated by commercial whaling, North Pacific Right Whales now face the threat of oil and gas development in their critical habitat.
Currently, three species of right whales are recognized by scientists. They are the North Pacific Right Whale (Eubalaena japonica), the North Atlantic Right Whale (Eubalaena glacialis) and the Southern Right Whale (Eubalaena australis). While recent genetic data supports this three-species taxonomy, right whales in the North Atlantic and North Pacific are still listed under the Endangered Species Act as a single species (Balaena glacialis). Separate listing of the North Pacific Right Whale would force the preparation of a recovery plan and other actions to protect the species and its habitat.
“With the announced extinction of the Yangtze River Dolphin this week, the North Pacific Right Whale now holds the dubious distinction of being the most endangered marine mammal in the world,” said Brendan Cummings, Ocean Program Director of the Center for Biological Diversity. “The Bush administration seems determined to have the North Pacific Right Whale follow the river dolphin into oblivion. Full protection under the Endangered Species Act will help the species avoid that fate.”
A copy of the complaint and more information on the North Pacific Right Whale is available on the Center for Biological Diversity’s Web site.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
The North Pacific Right Whale (Eubalaena japonica), once ranging from Baja California to Alaska, is the most endangered large whale in the world, with perhaps as few as 100 individuals remaining. Devastated by commercial whaling, North Pacific Right Whales now face the threat of oil and gas development in their critical habitat.
Currently, three species of right whales are recognized by scientists. They are the North Pacific Right Whale (Eubalaena japonica), the North Atlantic Right Whale (Eubalaena glacialis) and the Southern Right Whale (Eubalaena australis). While recent genetic data supports this three-species taxonomy, right whales in the North Atlantic and North Pacific are still listed under the Endangered Species Act as a single species (Balaena glacialis). Separate listing of the North Pacific Right Whale would force the preparation of a recovery plan and other actions to protect the species and its habitat.
“With the announced extinction of the Yangtze River Dolphin this week, the North Pacific Right Whale now holds the dubious distinction of being the most endangered marine mammal in the world,” said Brendan Cummings, Ocean Program Director of the Center for Biological Diversity. “The Bush administration seems determined to have the North Pacific Right Whale follow the river dolphin into oblivion. Full protection under the Endangered Species Act will help the species avoid that fate.”
A copy of the complaint and more information on the North Pacific Right Whale is available on the Center for Biological Diversity’s Web site.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Labels: environment, sealife
Friday, December 15, 2006
Splendid Toadfish - Creature of the Month
Toadfish are found on the sand and mud bottoms of coastal waters worldwide. They usually have broad heads and drab colours, and look something like toads. The Splendid Toadfish, though, is different.
Splendid Toadfish is attractively patterned in purple.
Most of its fins are edged in yellow with the pelvic fin
being entirely yellow. It also has a yellow mouth.
Also known as the Coral Toadfish, Sanopus splendidus
generally lives on sand under crevices or coral heads
in clear water, 10-25 m. It hunts at night, preying on
small fishes, snails and polychaete worms.
The Splendid Toadfish was thought to be only found in
Cozumel (Mexico) but sightings have also been reported
in Belize. However, it is not widespread and is
classified as vulnerable by the IUCN Red List of
Threatened Species (www.iucnredlist.org). This means
that although it is not Critically Endangered or
Endangered it is facing a high risk of extinction
in the wild in the medium-term future.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Thursday, December 14, 2006
Human Activity Seriously Damaging Coral Reef
The Barrier Reef shared by Belize, Guatemala, Honduras and Mexico, the second longest in the world, is being severely damaged by human activities. More than 80 percent of the sediment and 50 percent of the pollutants entering the coastal waters of the Barrier Reef originate from human activities in nearby mountainous Honduras, according to the World Resources Institute (WRI).
The analysis is the first to determine the origin and volume of sediment and pollution that run off agricultural lands, via the region's vast river networks, into the neighboring Gulf of Honduras and Caribbean Sea.
"As humans have altered the landscape, an increasing amount of sediment and nutrients are reaching coastal waters and the Mesoamerican Barrier Reef itself," said Lauretta Burke, a senior coastal ecosystem expert at WRI and co-author of the study. "Our analysis shows that pollution from farms in Honduras can inadvertently damage the entire Mesoamerican reef, which provides an important source of revenue from tourism and fisheries."
Along with more than 80 percent of sediment, more than half of all nutrients (both nitrogen and phosphorous) originate in Honduras.
Guatemala was identified as a source of about one-sixth of all sediments and about one-quarter of all nitrogen and phosphorous entering coastal waters along the reef.
Compared to the other countries, relatively minor percentages of the regional sediment load come from Belize and the Yucatan Peninsula in Mexico. Belize contributes between 10 to 15 percent of nutrients and Mexico is estimated to contribute about 5 percent of the nutrients from all modeled watersheds.
Of the 400 watersheds in the region, the Ulua watershed in Honduras was found to be the largest contributor of sediment, nitrogen, and phosphorous. Other large rivers found to be significant contributors of sediment and nutrients are the Patuca (in Honduras), Motagua (in Guatemala and Honduras), Aguan (in Honduras), Dulce (in Guatemala), Belize (in Belize), and Tinto o Negro (in Honduras).
Under land-use scenarios which favour free markets and little policy regarding the environment, nutrient delivery is likely to increase by about 10 percent by 2025, while sediment delivery might increase by 13 percent or more.
If environmental policies that favour sustainable development are implemented, nutrient and sediment delivery are likely to be reduced by at least 5% from current levels, promoting recovery of degraded corals.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
The analysis is the first to determine the origin and volume of sediment and pollution that run off agricultural lands, via the region's vast river networks, into the neighboring Gulf of Honduras and Caribbean Sea.
"As humans have altered the landscape, an increasing amount of sediment and nutrients are reaching coastal waters and the Mesoamerican Barrier Reef itself," said Lauretta Burke, a senior coastal ecosystem expert at WRI and co-author of the study. "Our analysis shows that pollution from farms in Honduras can inadvertently damage the entire Mesoamerican reef, which provides an important source of revenue from tourism and fisheries."
Along with more than 80 percent of sediment, more than half of all nutrients (both nitrogen and phosphorous) originate in Honduras.
Guatemala was identified as a source of about one-sixth of all sediments and about one-quarter of all nitrogen and phosphorous entering coastal waters along the reef.
Compared to the other countries, relatively minor percentages of the regional sediment load come from Belize and the Yucatan Peninsula in Mexico. Belize contributes between 10 to 15 percent of nutrients and Mexico is estimated to contribute about 5 percent of the nutrients from all modeled watersheds.
Of the 400 watersheds in the region, the Ulua watershed in Honduras was found to be the largest contributor of sediment, nitrogen, and phosphorous. Other large rivers found to be significant contributors of sediment and nutrients are the Patuca (in Honduras), Motagua (in Guatemala and Honduras), Aguan (in Honduras), Dulce (in Guatemala), Belize (in Belize), and Tinto o Negro (in Honduras).
Under land-use scenarios which favour free markets and little policy regarding the environment, nutrient delivery is likely to increase by about 10 percent by 2025, while sediment delivery might increase by 13 percent or more.
If environmental policies that favour sustainable development are implemented, nutrient and sediment delivery are likely to be reduced by at least 5% from current levels, promoting recovery of degraded corals.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Labels: coral, environment, sealife
Monday, December 11, 2006
Marine Census Discovers Many New Species
A host of record-breaking discoveries and revelations that stretch the extreme frontiers of marine knowledge were reported by the just-released Census of Marine Life 2006. They include life adapted to brutal conditions around 407ºC fluids spewing from a seafloor vent (the hottest ever discovered), a mighty microbe 1 cm in diameter, mysterious 1.8 kg (4 lb) lobsters off the Madagascar coast and a US school of fish the size of Manhattan Island.
Census seamount researchers found a shrimp, believed extinguished 50 million years ago, alive and well on an underwater peak in the Coral Sea. Neoglyphea neocaledonica was nicknamed “Jurassic shrimp” by its discoverers, who say it rivals the find in South Africa and Indonesia of the coelacanth, a prehistoric fish previously known only through fossils.
Among the many new species discovered by Census participants during 2006, a 1.8 kg (4 lb) rock lobster that Census explorers found off Madagascar may be the largest. Named Palinurus barbarae, the main body spans half a meter.
New and continuously improving techniques also let scientists collect and tag creatures in order to follow their movements. Marine animals themselves are thereby recruited as oceanographers, mapping their travels in the world’s oceans. With their help, the Census is creating new insights into the present and shifting distribution of global marine life.
Census researchers discovered 70 percent of the world’s oceans are shark-free. In an extensive study of the vast abyss below 3,000 m, deep-sea scientists found sharks were almost entirely absent and sought physiological and other explanations. Although many sharks live down to 1,500 m, they fail to colonize deeper, putting them more easily within reach of fisheries and thus endangered status.
Now in its 6th year, the census field work will continue until 2008. The results will be analysed and synthesized in 2009-10 with the goal by 2010 of an initial census describing what lived, now lives, and will live in the oceans.
Further Reading: Census of Marine Life
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Census seamount researchers found a shrimp, believed extinguished 50 million years ago, alive and well on an underwater peak in the Coral Sea. Neoglyphea neocaledonica was nicknamed “Jurassic shrimp” by its discoverers, who say it rivals the find in South Africa and Indonesia of the coelacanth, a prehistoric fish previously known only through fossils.
Among the many new species discovered by Census participants during 2006, a 1.8 kg (4 lb) rock lobster that Census explorers found off Madagascar may be the largest. Named Palinurus barbarae, the main body spans half a meter.
New and continuously improving techniques also let scientists collect and tag creatures in order to follow their movements. Marine animals themselves are thereby recruited as oceanographers, mapping their travels in the world’s oceans. With their help, the Census is creating new insights into the present and shifting distribution of global marine life.
Census researchers discovered 70 percent of the world’s oceans are shark-free. In an extensive study of the vast abyss below 3,000 m, deep-sea scientists found sharks were almost entirely absent and sought physiological and other explanations. Although many sharks live down to 1,500 m, they fail to colonize deeper, putting them more easily within reach of fisheries and thus endangered status.
Now in its 6th year, the census field work will continue until 2008. The results will be analysed and synthesized in 2009-10 with the goal by 2010 of an initial census describing what lived, now lives, and will live in the oceans.
Further Reading: Census of Marine Life
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Labels: environment, sealife
Thursday, December 07, 2006
Breath-Hold Divers Get Decompression Sickness Too
Decompression sickness, or the bends, is caused by nitrogen bubbles forming in the body. As the pressure reduces during ascent, the volume of gas in the blood and tissues increases. If the ascent is too fast the bubbles may reach a dangerous size and prevent blood flow or damage tissues.
Normally associated with SCUBA diving, decompression sickness (DCS) is also be a risk for repetitive breath-hold diving. This was put forward as early as 1965 but is still not widely acknowledged.
A new study in the Research in Sports Medicine journal compared four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record gets deeper and deeper.
The researchers - JD Schipke, E Gams, and O Kallweit of the University Hospital Duesseldorf - report some 90 cases in which DCS occurred after repetitive breath-hold dives. They suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. They propose the development of easily manageable algorithms for the prevention of avoidable accidents.
Journal Reference: Res Sports Med, 2006; 14(3): 163-78.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Normally associated with SCUBA diving, decompression sickness (DCS) is also be a risk for repetitive breath-hold diving. This was put forward as early as 1965 but is still not widely acknowledged.
A new study in the Research in Sports Medicine journal compared four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record gets deeper and deeper.
The researchers - JD Schipke, E Gams, and O Kallweit of the University Hospital Duesseldorf - report some 90 cases in which DCS occurred after repetitive breath-hold dives. They suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. They propose the development of easily manageable algorithms for the prevention of avoidable accidents.
Journal Reference: Res Sports Med, 2006; 14(3): 163-78.
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Tuesday, December 05, 2006
Save 945 whales - your ideas needed
Greenpeace want you to help them put an end to whaling in the Southern Ocean. Go to their new web site at http://whales.greenpeace.org/global where you can get inspired by other people's ideas, rate them, improve them and add your own.
The blue whales of the Antarctic are at less than 1 percent of their original abundance, despite 40 years of complete protection. Some populations of whales are recovering but some are not. Only one population, the East Pacific grey whale, is thought to have recovered to its original abundance, but the closely related West Pacific grey whale population is the most endangered in the world. It hovers on the edge of extinction with just over 100 remaining.
Source: Greenpeace
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
The blue whales of the Antarctic are at less than 1 percent of their original abundance, despite 40 years of complete protection. Some populations of whales are recovering but some are not. Only one population, the East Pacific grey whale, is thought to have recovered to its original abundance, but the closely related West Pacific grey whale population is the most endangered in the world. It hovers on the edge of extinction with just over 100 remaining.
Source: Greenpeace
What do you think of this news item? Start a discussion.
--
Subscribe to SCUBA News (ISSN 1476-8011) for more free news, articles, diving reports and marine life descriptions - http://www.scubatravel.co.uk/news.html
Labels: sealife, whale and dolphins
