The yearly manatee count revealed a record number of manatees this year. The survey counted 3807 manatees which is about 500 more than the previous record from 2001.
Manatee with calf
Experts do however say that it is too early to cheer and that one shouldn’t read too much into this as this year offered ideal conditions for spotting manatees. Cold temperatures made the manatees gather in warm clear waters around nuclear power plants and natural springs making them easy to spot. The previous record year 2001 – when about 1000 more manatees were counted than the year before and the year after – also offered similar conditions. It is important to remember that the count doesn’t reflect the actual number of manatees but rather a minimum number of manatees as not all of them can be found and counted.
Wildlife managers and manatee advocates do however call the number encouraging and say that it might indicate that the manatee population is slowly recovering as the number is higher then the numbers the previous record year. They say that the count supports population models suggesting manatees are increasing in Northwest Florida, along the Atlantic Coast and on the upper St. Johns River. Pat Rose, executive director of the “Save The Manatee Club” does however add that the numbers in Southwest Florida and the Everglades, home to about 40 percent of all manatees in Florida, are believed to be in continuing decline. Data on this region is however much more scare as it is hard to keep track on the animals in the dark waters found in this area.
Considering that scientists earlier estimated the manatee population in all of Florida to be below 1500 animals it can only be concluded that the conservation process have been a success and with 3807 animals it seems clear that the situation is much better than it once were, even if there still is much work to do to protect these gentle giants.
This story might be a few days old but is still of interest and as I haven’t been able to get to it sooner I decided to post about it today.
Indonesia will allow trawling in selected areas for the first time in 30 years, maritime ministry official Bambang Sutejo announced on January 15. Trawling will be allowed off four areas of Indonesia East Kalimantan province, despite concerns about overfishing.
“There will not be overfishing this time as we’re only allowing small boats to trawl, and it’s not allowed in other parts of Indonesia,” says Sutejo, adding that legalising trawling would help fight illegal trawlers.
According to Chalid Muhammad of the independent Green Institute, trawling has a destructive impact on the marine environment and will intensify the problem with overfishing in Indonesian waters. “The total amount of fish caught is getting smaller each day while their imports are getting bigger,” says Muhammad.
Muhammad also feels a legalization of trawling will embarrass Indonesia as it prepares to host the World Ocean Conference. “If the government allows this, Indonesia will have a weak standing during the World Ocean Conference as sustainable management of marine resources will be discussed,” Muhammad said. The World Ocean Conference is an international gathering of policymakers and scientists held in May 2009.
Kalimantan is the Indonesian portion of the island Borneo, the third largest island in the world, and is divided into four provinces: East Kalimantan, West Kalimantan, South Kalimantan, and Central Kalimantan.
What is trawling?
Trawling is a fishing practise where fishing boats tow long nets behind them. These nets do not only scoop up commercially valuable fish, but all sorts of marine life. Trawling is divided into bottom trawling and midwater trawling, depending on where in the water column the trawling takes place. Bottom trawling is especially harmful to marine environments since it can cause severe incidental damage to the sea bottoms and deep water coral reefs.
On January 22, 48 sperm whales were found stranded on Perkins Island, off the northwest coast of Tasmania, Australia Despite efforts to rescue the whales, only five specimens were alive by late Friday and three of them died during the night. Rescuers now hope that at least these two whales will be able to return safely to the sea.
The reason behind the stranding is believed to be a special wind pattern that brings nutrients up to the surface. Karen Evans, a government scientist, said the winds occur in a 10-year cycle in this region. As the winds bring nutrients up through the water column, squids and other suitable sperm whale prey follows and this is what lures the whales too close to the shallows. In November, two large groups of pilot whales stranded in the same region.
“I’ve flown over this area where the sperm whales are, and it’s almost like a whale death trap,” says Evans. “There are lots of wide sandbars and beaches, all kinds of traps for animals that go into it.”
The Sperm Whale (Physeter macrocephalus or Physeter catodon) is the largest of all toothed whales and largest living toothed animal. Some of the animals that where found stranded on Perkins Island were more than 30 feet (over 9 metres) in length, but male sperm whales can actually reach a length of at least 67 feet (over 20 metres). Sperm whales feed mainly on squid and fish, including Colossal squid (Mesonychoteuthis hamiltoni) and Giant squids of the genus Architeuthis.
New research has revealed that the tapetail, bignose and whalefish are in fact all the same fish.
For decades, three different names have been used for three very different looking underwater creatures: the Tapetail, the Bignose and the Whalefish. A team of seven scientists*, including Smithsonian curator Dr Dave Johnson, has now discovered that these three fishes are in fact part of the same family.
After studying the body structures of the tapetails (Mirapinnidae), bignose fish (Megalomycteridae) and whalefish (Cetomimidae) and taking advantage of modern DNA-analysis, the team realized that the three are actually the larvae, male and female, respectively, of a single fish family – Cetomimidae (also known as Flabby whalefish).
“This is an incredibly significant and exciting finding,” says Johnson. “For decades scientists have wondered why all tapetails were sexually immature, all bignose fishes were males and all whalefishes were females and had no known larval stages. The answer to part of that question was right under our noses all along—the specimens of tapetails and bignose fishes that were used to describe their original families included transitional forms—we just needed to study them more carefully.”
If you wish to find out more, the article “Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families” has been published in the journal Biology Letters by the Royal Society, London.
http://publishing.royalsociety.org/
http://journals.royalsociety.org/content/g06648352k5m1562/
* The seven scientists behind the discovery are:
G.David Johnson, Division of Fishes, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
John R. Paxton, Ichthyology, Australian Museum, Sydney, New South Wales 2010, Australia
Tracey T. Sutton, Virginia Institute of Marine Science, Gloucester Point, VA 23062, USA
Takashi P. Satoh, Marine Bioscience, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639, Japan
Tetsuya Sado, Zoology, Natural History Museum and Institute, Chuo-ku, Chiba 266-8682, Japan
Mutsumi Nishida, Marine Bioscience, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639, Japan
Masaki Miya, Zoology, Natural History Museum and Institute, Chuo-ku, Chiba 266-8682, Japan
Sri Lankan scientists have described a new species of fish from south-western Sri Lanka and placed in the genus Puntius.
Unlike its close relatives in Sri Lanka and India, the new species Puntius kelumi feature a combination of a smooth last unbranched dorsal-fin ray, a body depth that is 28.6-35.5 % of standard length (SL), maxillary barbels (about as long as the eye diameter) but no rostral barbels, 20-23 lateral-line scales on the body, and ½3/1/2½ scales in transverse line from mid-dorsum to pelvic-fin origin. One breeding males, the sides of the head and body are rough and extensively tuberculated.
Puntius kelumi is primarily found in large streams with clear water that flows down from the mountains. The bottom is typically made up by granite, pebbles and/or sand and is often littered with boulders.
The description was published by the journal Ichthyological Exploration of Freshwaters.
For more information about Puntius kelumi, see the paper: Pethiyagoda, R, A Silva, K Maduwage and M Meegaskumbura (2008) Puntius kelumi, a new species of cyprinid fish from Sri Lanka (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters 19, pp. 201–214.
http://www.pfeil-verlag.de/04biol/pdf/ief19_3_02.pdf
A picture of the new species can be seen here
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Puntius is a genus of ray-finned fishes in the family Cyprinidae. All known members of the genus are native to Southeast Asia and India, including Sri Lanka. The name Puntius is derived from the word pungti, which is the term for small cyprinids in the Bangla (Bengali) language.
Puntius fish are commonly referred to as spotted barbs, but some species display vertical black bands instead of spots. Spotted barbs are commonly kept by aquarists and are known to be active, curious and bold. Many of them are unsuitable companions for fish with long and flowing finnage since they tend to nip such fins, a habit which causes both injury and stress in the afflicted animal.
A group of scientists from the Catalyst One expedition has discovered three previously unknown coral reefs 35 miles of the coast of Florida. The coral reefs consist mainly of Lophelia coral and are located at a depth of 450 metres (1475 feet).
Lophelia pertusa is a cold-water coral famous for its lack of zooxanthellae. The well known coral reefs found in warm, shallow waters – such as the Great Barrier Reef – consist of reef building corals that utilize energy from the sun by forming symbiotic relationship with photosynthesising algae. Lophelia pertusa on the other hand lives at great depths where there isn’t enough sunlight to sustain photosynthesising creatures, and survives by feeding on plankton.
The deep-sea reef habitat formed by Lophelia pertusa is important for a long row of deep water species, such as lanternfish, hatchetfish, conger eels and various molluscs, amphipods, and brittle stars. The reefs that we see today are extremely old, since Lophelia reefs typically grow no more than 1 mm per year. Unfortunately, these deep reefs are today being harmed by trawling and oil extraction.
The Catalyst One expedition will submit its newly acquired information to the South Atlantic Fisheries Management Council to provide further data for the proposed Deep Coral Habitat Area of Particular Concern (HAPC).
The Catalyst One expedition is a collaboration between the Waitt Institute for Discovery, the Harbor Branch Oceanographic Institute at Florida Atlantic University, and Woods Hole Oceanographic Institute. It combines the scientific expertise of Harbor Branch’s senior research professor, John Reed, with Woods Hole’s high-tech operations skills and Waitt Institute’s modern autonomous underwater vehicles (AUVs).
In order to reach these great depths and efficiently explore substantial areas, the expedition used REMUS 6000 AUV vehicles capable of carrying two kinds of sonar and a camera. With this type of equipment, each mission can last for up to 18 hours and provides the researchers with mosaic pictures of the bottom, pictures that can then be pieced together to form a detailed, high-definition map.
“Rarely do scientific expeditions produce solid results this quickly,” says Dr Shirley Pomponi, executive director of Harbor Branch. “This is a big win for the resource managers tasked with protecting these reefs and proof that cutting edge technology combined with the seamless teamwork of the three organisations involved in Catalyst One can accelerate the pace of discovery.”
You can find more information about the Catalyst program at the Waitt Institute for Discovery.
“Most people agree that mammals and birds can feel pain, but people are less sure about fish,” says project leader Øyvind Aas-Hansen of NOFIMA, an aquaculture research institute whose headquarters are in Tromsø, Norway.
Fish show many signs of being able to experience pain, but we still know very little about how their brains react to stimuli that would cause mammals and birds to feel pain. According to some scientists, the brain of a fish is not equipped with certain structures needed to process pain, but others believe that fish nevertheless do sense some type of pain.
What we do know is that fish show a long row of behavioural responses that could be interpreted as signs of pain, such as avoidance reactions. Fish are also capable of producing pain-relieving opiates and the fish brain is equipped with receptors for both pain and opiates.
The European researchers hope that modern medical technology, especially functional magnetic resonance imaging (fMRI) and electroencephalograms (EEGs) will make it possible for them to learn more about how the cod brain actually works. The aim of the study is to indentify which parts of the cod brain that becomes activated when a cod is exposed to potentially painful stimuli, and the researchers will also study how these signals are processed.
In order to test the brain of a fish, there is no need to expose it to any type of severe or prolonged pain; a mild stimulus that simply provokes an unpleasant sensation is enough to see how the brain reacts. “We will use the same procedures as those used on healthy human volunteers,” Dr Aas-Hansen explains.
If cods are indeed able to feel pain, Dr Aas-Hansen hopes that the results of the study will be used as yet another argument in favour of keeping aquarium fish in benevolent conditions. The study is however unlikely to affect European legislation since most regulations already assume that fish can feel pain.
Dr Aas-Hansen also points out how comparative research on how the brain works in different animals can give an insight into our own human brain. “This is ground-breaking work,” he says. “No other scientists have previously studied the cod’aquarius brain this way.”
The project will run for three years and is funded by the Norwegian Research Council.
Rare coral species may be saving themselves from extinction by hybridising with other coral species, says Australian scientist Zoe Richards. Richards and his colleagues have studied 14 rare[1] and eight common coral species of the genus Acropora in the Indo-Pacific.
In order to find out more about hybridisation among corals, the team did a phylogenetic analysis using the highly polymorphic single-copy nuclear Pax-C 46/47 intron and the mitochondrial DNA (mtDNA) control region as markers.
The analysis showed that many of the rare species are polyphyletic for both Pax-C and mitochondrial phylogenies, and this is seen as a clear sign of interspecific hybridisation.
The results of the study “Some rare Indo-Pacific coral species are probable hybrids” by Richards, Oppen, Wallace, Willis and Miller were published in a recent issue of the journal PLoS ONE[2].
In their paper, the authors explain how “[t]he results presented here imply that a number of rare Indo-Pacific Acropora species are the products of recent hybridisation events, and highlight the significance of hybridisation in coral diversification. Whether these species have hybrid origins or have evolved and then hybridised in the absence of conspecific gametes remains to be elucidated.”
“In summary, although it has often been assumed that small populations have a decreased potential for adaptation, our analyses imply that some rare acroporid corals may actually have increased adaptive potential as a consequence of introgressive hybridisation, and therefore may be less vulnerable to extinction than has been assumed.”
[1] For the purposes of this study, rare species were defined as those which have been recorded at less than 2.5% of sites for which data are available in the World Wide Acropora Database.
[2] Richards ZT, MJH van Oppen, CC Wallace, BL Willis and DJ Miller (2008) Some rare Indo-Pacific coral species are probable hybrids. PLoS ONE 3(9), e3240. doi:10.1371/journal.pone.0003240
Vast amounts of creatures looking like jelly balls have begun to appear off the eastern coast of Australia, and researchers now suspect that these animals may help slow down global warming by moving carbon dioxide from the atmosphere to the ocean floor.
The proper English name for this “jelly ball” being is salp. A salp is a barrel-shaped free-floating tunicate that moves around in the ocean by contracting and relaxing its gelatinous body. Just like the other tunicates, the salp is a filter feeder that loves to eat phytoplankton and this is why it has caught the attention of scientists researching global warming.
Phytoplankton are famous for their ability to absorb carbon dioxide from the top level of the sea, and a salp feasting on phytoplankton will excrete that carbon dioxide in the form of faeces. The faeces will drop to the ocean floor; thus lowering the amount of carbon dioxide present in the upper part of the ocean. Since the carbon dioxide found in this level of the sea chiefly hails from the atmosphere, phytoplankton and salps are a great aid when it comes to removing carbon dioxide from the air. Salps will also bring carbon down to the ocean floor when they die, which happens fairly often since the life cycle of this organism is no more than a few weeks.
Salp species can be found in marine environments all over the world, but they are most abundant and concentrated in the Southern Ocean near Antarctica where it is possible to encounter enormous swarms of salp. Over the last 100 years, krill populations in the Southern Ocean have declined and salp populations seem to be replacing them in this cold ecosystem. According to researcher Mark Baird of the Australian Commonwealth Scientific and Research Organization (CSIRO), the amount of salps in the waters off Australia are also on the increase, at least according to a survey carried out last month by CSIRO and the University of New South Wales.
While salp may help slow down global warming, their increase may also cause problems. Salp has a fairly low nutrient content and salps replacing nutrient rich krill in the Southern Sea may therefore prove detrimental for oceanic animals higher up in the food chain.
The U.S. Bureau of Reclamation is now carrying out tests in hope of finding out if bacteria can aid them in their struggle against invasive mussel species that are threatening to spread across the West’s waterways.
During the summer of 2008, a preliminary test was executed at Davis Dam on the Colorado River at Laughlin in Nevada. In this dam, Quagga mussels (Dreissena rostriformis bugensis) were exposed to dead bacteria of the Pseudomonas fluorescens species, a non-infectious bacterium that is commonly found in water, soil and food.
Quagga Mussels
During the first test the mussels where exposed to bacteria in jars, but the next test will take place in 10-20 gallon aquariums to in order to more accurately mimic real dam conditions. Water will flow through the aquariums, but will not be released back into the river – it will instead be disposed of through an evaporation pond. A third experiment is also planned, where bacteria will be released in a domestic water intake line which is currently encrusted with a 2-3 inches thick layer of mussels (approximately 5-7.5 cm).
“We are always looking for new, more effective techniques for managing mussels, and this one looks very safe and very promising,” says Reclamation scientist Fred Nibling. “We’ll have a series of tests where we’re going to be testing off-line, off the river, so we can have the data to where we can apply for the permits to test elsewhere.
If the initial testing proves to be successful, the Bureau of Reclamation hopes to have a larger scale test approved by the Environmental Protection Agency.
The U.S. Bureau of Reclamation got the idea to use Pseudomonas fluorescens from Daniel Molloy, a researcher at the New York State Museum who discovered that both zebra and quagga mussels died if they ingest the bacterium. He confirmed the effect in 1998 and the method was patented by the museum. Eventually, the Californian firm Marrone Organic Innovations was awarded a National Science Foundation grant to commercialize the technology.
According to Molloy’s research, a mussel needs to ingest a high density of a strain of the bacteria in order for the bacteria to be lethal. If the density is high enough, a toxin inside the bacterium cell will efficiently devastate the digestive tract of the animal.
One advantage with Pseudomonas fluorescens compared to conventional anti-mussel treatments like chlorine is that mussels recognize chlorine as dangerous and close their feeding valves to keep the chemical out. They do however happily devour Pseudomonas fluorescens. Another important aspect is that research has found that Pseudomonas fluorescens does not kill fish or shellfish.
If large scale testing also proves successful, the Bureau of Reclamation say they wish to meet with municipal public works and water authority officials before the bacterium is put into general use. “We want to make sure they’re very comfortable and they have a chance to ask questions,” says Nibbling.
Zebra mussels