White Shark - Terry Gross

A team of researchers headed by Taylor Chapple, a UC Davis doctoral student, has made the first rigorous scientific estimate of White shark (Carcharodon carcharias) numbers in the northeast Pacific Ocean.

The researchers used small boats to reach spots in the Pacific Ocean where white whales congregate and lured them into photo range with a fake seal attached to a fishing line. Out of all the photographs taken, 321 photos showed dorsal fin edges. The dorsal fin edges of white sharks are jagged and each individual displays its own unique pattern. The photographs could therefore be used to identify individual sharks – 131 in total.

The research team then entered this information into statistical models to estimate the number of sharks in the region. According to their estimate, there are 219 adult* and sub-adult** white sharks in this area.

“This low number was a real surprise,” says Chapple. “It’s lower than we expected, and also substantially smaller than populations of other large marine predators, such as killer whales and polar bears. However, this estimate only represents a single point in time; further research will tell us if this number represents a healthy, viable population, or one critically in danger of collapse, or something in-between.”

The white shark population in the northeast Pacific Ocean is one of three known white shark populations in the world; the other two are found off the coast of South Africa and off Australia/New Zealand, respectively.

Earlier studies using satellite tagging have shown that the white sharks of the northeast Pacific Ocean have an annual migration pattern. Each year, they move from the region off the coast of central California and Mexico’s Guadalupe Island to the Hawaiian Islands or to an area of open ocean located between the Baja Peninsula and Hawaii. The latter destination has even been dubbed “White Shark Café” due to its popularity among white sharks. After spending some time away from the mainland, the sharks journey back to coastal waters.

“We’ve found that these white sharks return to the same regions of the coast year after year,” says Barbara Block, marine biologist at Stanford University and one of the co-authors of the pioneering white shark census. “It is this fact that makes it possible to estimate their numbers. Our goal is to keep track of our ocean predators.”

The paper “A first estimate of white shark, Carcharodon carcharias, abundance off Central California” (http://dx.doi.org/10.1098/rsbl.2011.0124) has been published in the journal Biology Letters (http://rsbl.royalsocietypublishing.org).

* Adult white sharks are the ones that have reached sexual maturity, something which happens when the male is roughly 13 feet and the female is about 15 feet in length.

**Sub-adults are roughly 8 feet or longer (but has not reached sexual maturity); at this size their dietary focus shifts from mostly fish to mostly marine mammals.

Study co-authors

• Taylor K. Chapple, Wildlife, Fish and Conservation Biology, University of California Davis, USA and Max Planck Institute, Germanyhttp://www.topp.org/user/taylorchapple
• Salvador J. Jorgensen, Hopkins Marine Station of Stanford University, USA and Monterey Bay Aquarium, USAhttp://www.topp.org/blog/salvo
• Scot D. Anderson, Point Reyes National Seashore, USA
• Paul E. Kanive, Department of Ecology, Montana State University, USA
• A. Peter Klimley, Wildlife, Fish and Conservation Biology, University of California Davis, USAhttp://wfcb.ucdavis.edu/people/faculty/klimley.php
• Louis W. Botsford, Wildlife, Fish and Conservation Biology, University of California Davis, USAhttp://wfcb.ucdavis.edu/people/faculty/botsford.php
• Barbara A. Block, Hopkins Marine Station of Stanford University, USAhttp://www-marine.stanford.edu/block.htm

Funding

• The National Oceanic and Atmospheric Association (NOAA) Fisheries through the Partnership for Education in Marine Resource and Ecosystem Management (PEMREM) and the NOAA Fisheries/Sea Grant Fellowship Program
• The Gordon and Betty Moore Foundation
• The National Parks Service’s Pacific Coast Science and Learning Center
• Monterey Bay Aquarium
• UC Davis Bodega Marine Laboratory
• Patricia King, member of the Point Reyes National Seashore Association



Trash gyre location and currents

For those who wish to boldly go where just a handful of researchers has gone before, the Algalita Marine Research Foundation is now offering tickets to visit the Great Pacific Garbage Gyre.

In collaboration with Pangaea Explorations, a team of Algalita researchers will embark on a three week long scientific voyage through the Pacific Trash Vortex, a gyre of marine litter located roughly between 135° to 155°W to 42°N.

“We’ll be looking for changes in the accumulation of plastic in the North Pacific Gyre,” says Marcus Eriksen, who will lead the expedition’s research as Algalita’s Director of Project Development. “We suspect there’s greater accumulation, which means more harm to sea life and potentially to humans.”

The cost of each ticket is $10 000, and the net proceeds will be used to fund Algalita’s scientific research and educational outreach.

And even though you’re coughing up $10 000 for your fare, don’t expect a leisure cruise. The Sea Dragon, Pangaea’s 72-foot racing sloop, only have enough room for 14 people, including 4 professional crew members, and guests will be expected to help sail and maintain the vessel, stand watch during the night and cook up some hearty meals in the galley. To be considered for a spot on the Sea Dragon you must be fit enough to pull lines, raise sails and lift 1/3 of your weight. You must also be willing to get some very hands-on experience from garbage sorting.

“On this voyage, you’ll earn your sea legs and rough hands hauling in lines and hoisting sails, but you’ll also be “doing the science” side-by-side with researchers,” says Eriksen. “You’ll need to be fit as you prepare to trawl the sea, sort plastic, preserve samples and catalog it all.”

The ship leaves Hawaii on July 7 2011 and is expected to land in Vancouver on July 27.
To find out more and purchase your ticket, go to http://www.algalita.org/research/NorthPacificGyreVoyage.html

An international consortium has been formed to study the potential effects of adding iron to the ocean to promote the growth of phytoplankton. Phytoplankton use carbon dioxide from the atmosphere and ocean fertilization might therefore be a way of mitigating the effects of global warming. When phytoplankton die, organic carbon sinks to the seafloor where it may remain for decades, centuries or even longer – we still do not now much about the time-line.

Iron fertilization of the ocean is far from uncontroversial, since it is very difficult to foresee the long term effects of such a project. The international consortium, which has been named In-Situ Iron Studies (ISIS) consortium , will carry out iron fertilization experiments in the open ocean in an effort in to answer some of the questions regarding how iron affects the ocean’s capacity for dragging carbon dioxide from the air and into the water. All experiments will adhere to the London Convention/London Protocol regarding ocean iron fertilization research.

“A great deal remains to be learned about ocean iron fertilization and how effective it could be in storing carbon dioxide in the oceans, and the formation of this consortium is an important first step,” says Lewis Rothstein, professor of oceanography at the University of Rhode Island. “This is not a call for climate engineering; on the contrary this is a research consortium. It is premature to advocate for large-scale ocean iron fertilization, but it is time to conduct a focused research experiment that will examine the concept as comprehensively as we can. We want to make sure that it doesn’t generate harmful side effects that might negatively affect the marine ecosystem.”

The twelve ISIS-members are the following:
University of Rhode Island, USA
University of Hawaii, USA
University of Illinois at Urbana-Champaign, USA
University of Maine, USA
University of Massachusetts Boston, USA
University of Plymouth, UK
Xiamen University, Fujian, China
The Antarctic Climate and Ecosystems Cooperative Research Centre, Australia
Netherlands Institute for Sea Research, The Netherlands
The National Oceanography Centre, UK
Moss Landing Marine Laboratories, California, USA
Woods Hole Oceanographic Institution, Massachusetts, USA

Dolphins. Picture from aquariumposter.com

On February 21, three baby dolphins were found dead on the shores of Horn Island, and on February 22 the finding of a fourth carcass was confirmed by The Institute for Marine Mammal Studies (IMMS). This brings the amount of dead infant dolphins reported since January up to 18. Since the beginning of the year, 10 adult dolphins have also been found dead.

Located roughly 12 miles (20 km) south of Ocean Springs, Mississippi, Horn Island is one of several islands that make up the Gulf Islands National Seashore Park. National Resource Advisory employees are currently working with BP cleanup crews on the island.

Blair Mase, marine mammal stranding coordinator at The National Oceanic and Atmospheric Administration (NOAA) is concerned about the high number of wash up dead dolphins.

“We’re definitely keeping a close eye on this situation,” says Mase. “We’re comparing this to previous years, trying to find out what’s going on here.”

We are now early in the birthing season for dolphins in the area, and so far, 18 bodies of baby dolphins have been found where the baby was either stillborn or died shortly after birth.

“We’re trying to determine if we do in fact have still births,” says Mase. “There are more in Mississippi than in Alabama and Louisiana. With the oil spill, it is difficult. We’re trying to determine what’s causing this. It could be infectious related. Or it could be non-infection. We run the gamut of causes.”

The necropsy of the dead dolphins will hopefully help shed some light on the situation.

African Wolf aka Egyptian Jackal

This is not really fish related but cool enough to warrant a post here anyway. Scientists have discovered a new species of Wolf in Egypt. A team a researchers from Oxford University’s Wildlife Conservation Research Unit (WildCRU), the University of Oslo, and Addis Ababa University, with funding from the University of Oslo, shows that Gray wolves reached Africa around 3 million years ago before spreading throughout the northern hemisphere. The new wolf is a relative of the Holarctic grey wolf, the Indian wolf and the Himalayan wolf.

The Egyptian jackal (Canis aureus lupaster) is an importan part of the Egyptian mythology and has until now been considered a subspecies of the Golden jackal (Canis aureus) but this new research show that the egyptian jackal is infact a species of wolf. This new species is not closely related to the rare Ethiopian wolves. Ethiopian wolves are a relatively recent of spring from the gray wolf complex while this new species, ”African wolf” (suggested name by Professor Sillero), likely arrived in Africa much earlier.

Professor David Macdonald says: “A wolf in Africa is not only important conservation news, but raises fascinating biological questions about how the new African wolf evolved and lived alongside not only the real golden jackals but also the vanishingly rare Ethiopian wolf, which is a very different species with which the new discovery should not be confused.”

The jackal is important in Egyptian Mythology

The team also found genetically very similar specimens to this new wolf in the highlands of Ethiopia, 2,500 km from Egypt, suggesting that the new species might have a large distrobution and that it is not just found in Egypt.

The conservational status of this new species is not known.

Professor Sillero says: “It seems as if the Egyptian jackal is urgently set for a name-change, and its unique status as the only member of the grey wolf complex in Africa suggests that it should be re-named ‘the African wolf’.”

WildCRU is part of Oxford University’s Department of Zoology.

If you want to read the entire paper (direct link) you can do so at PlosOne:

Scientists researching the Gulf of Mexico have found an underwater mass of dead biological material that appears to be growing as microscopic algae and bacteria get trapped and die. The blob is at least three feet (90 cm) thick and spans two-thirds of a mile (1 mile = 1 609 meters) parallel to the coast just off the Florida Panhandle, within the site of Perdido Key. The blob smells like rotten eggs and feels similar to jelly.

The researchers have been unable to determine how the blob was formed, where it comes from or where it will go. Tests show that the material is nearly 100% biological and less than a year old. It is also clear that tiny organisms have gotten stuck in the sticky blob and died. Tests carried out by the researchers also showed that the blob has no connection to land.

“It seems to be a combination of algae and bacteria,” says David Hollander, a chemical oceanographer with the University of South Florida. According to Hollander, the substance is toxic and “extraordinarily sticky”.

Scientists are not ruling out a connection to last years’ Deepwater Horizon disaster, but so far none of the tests have shown any sign of oil.

Researchers encountered the blob for the first time in December as they were searching for oily sediments on the sea floor. They did find such sediments, but they also got a tip about something weird floating around roughly half a mile from Perdido Pass and this caused them to change their plans and head over to the area to investigate.

The environment where the blob can be found is a relatively pristine sloping shelf. Normally, wave action will sweep away any sediments here.

Hollander and his team are planning to return to the blob within a few weeks to gather more samples, since they were unable to get any material from the bottom of the blob during their last visit. They will also try to map out the entire blob to be able to see exactly how big it is.



Red snapper

A large amount of New Zealand’s seagrass have been killed by sediments released from land development. The seagrass bed at Whangarei Harbour has for instance been reduced from 14 sq km in the 1960s to virtually non-existant today. And sedimentation this is not a new problem – between 1959 and 1966 Tauranga Harbour lost 90 per cent of its seagrass.

Researchers at New Zealands’s National Institute of Water & Atmospheric Research are now fitting the floor of the Whangapoua Estuary with plastic seagrass in an attempt to show how New Zealand’s fish stocks could be boosted by restoring the seagrass habitats. The “seagrass” consists of plastic fronds attached to wire frames, and the length of the fronds varies from 5 cm to 30 cm.

“We made them with tantalising long blades of artificial grass, the things fish really go for,” says NIWA fisheries ecologist Dr Mark Morrison. “What we found, initially, is that fish are really looking for shelter and seagrasses provide good protection to fish.”

The largest density of fish could be found where the density of seagrass was also at its largest.

Fish is now being tagged to make it possible for the researchers to track both growth rate and survival rate.

When salmon is farmed in large-scale monocultures, the fish tend to become susceptible to disease and parasites. Researchers working for the organization Nofima have now found a way of combating the parasite salmon lice in fish farms without using any dangerous toxins. Wrasse loves to eat lice, so the researchers simply added wrasse to the salmon populations and the result was astonishing.

During the trials, the most efficient lice eater turned out to be the Ballan wrasse (Labrus bergylta). In addition to being highly efficient, it also gathered lice at lower temperatures than the other Wrasse species that took part in the experiment.

When Ballan wrasse was used, roughly 2-5% wrasse was needed for salmon living in sea cages. This means that a population of 100 000 salmon will need somewhere between 2 000 and 5 000 wrasse to stay deloused. A new larger project will now be prepared to make sure there is an adequate supply of the lice eaters in Norway. The project will go on for three years and has received funding from The Fishery and Aquaculture Industry Research Fund (FHF).

The effort which is now commencing is unique in both a Norwegian and global context. Norway is the only salmon-producing country that is using wrasse on a large scale to combat salmon lice,” says Arne Karlsen, managing director of FHF.

Removing large amounts of Ballan wrasse from the wild to keep in salmon farms could cause serious damage to the wild populations and the goal of the Norwegian project is therefore to cover at least 25% of the demand with farmed wrasse by 2013.

In addition to Nofima and FHF, the project will also involve SINTEF Fisheries and Aquaculture, the Institute of Marine Research and the Norwegian University of Science and Technology.

Several Norwegian projects are already taking a closer look at the Ballan wrasse, including a research venture concerning Ballan wrasse farming that started last year with funding totaling NOK 12 million from the Research Council of Norway, FHF and industry partners.

” It is estimated that the total Norwegian effort on Ballan wrasse farming is in the vicinity of NOK 100 million,” says Kjell Maroni, research and development director at FHF

The researchers will now have to find out how to carry out large-scale wrasse farming without being plagued by the same problems with disease and parasites as the salmon farms.



A researcher has commented that this past Wednesday his team has discovered that a local freshwater salmon species classified as extinct by the government about seven decades ago, still lives on in Lake Saiko.

Tetsuji Nakabo, Kyoto University professor, commented that he took a look at nine fish from the lake and discovered that they were strikingly similar – in fact the same as – the “kunimasu” or “black kokanee” species of salmon.

If this find is confirmed, it will be the very first time a fish species in Japan which has been classified as extinct has been found living still, the Environment Ministry explained. The ministry has commented it is going to do its best to verify the claims of Nakabo and review its classification of the salmon.

The salmon, a landlocked sockeye, had been seen earlier on only in Lake Tazwa, and was believed to have died off due to an inflow of toxic water sometime in the 1940’s.

However, Nakabo explained there are records which show the salmon’s eggs were taken to other lakes, including Lake Saiko and Lake Biwa, to help improve stocks about half a decade earlier than when they supposedly went extinct.

The species “likely propagated from the eggs from that time,” Nakabo explained.

This discovery came in February, after Nakabo asked fish expert Sakana-kun to show a likeness of the extinct fish.

Sakana-kun requested samples of “himemasu” – a fish similar to that of the “kunimasu” – and discovered they were very similar, and just possibly the same!

Minister for Natural Environment Fisheries, Richard Benyon, has cautioned that the sustainability of mackerel in the future is at risk.

This calamity is already being called “Cod Wars II”.

The EU and Britain are on the brink of a serious trade battle with Iceland and the Faroe Islands after discussions about changing fishing quotas failed miserably.

Faroes and Iceland have both increased their fishing quotas substantially, and have basically up and walked out of discussions with the EU, which were supposed to find a middle ground agreeable to all concerned.

The other nations of the EU – including Britain, much to everyone’s surprise – are looking to take some extreme actions which might just force Iceland and the Faroes to limit the amount of mackerel they reel in.

There has already been talk of trade sanctions which would effectively ban the import of mackerel.

This is very much like the Cod Wars of the 50’s and 70’s, when Britain and Iceland were fighting over the rights to fish in the North Atlantic.

It got so serious that even the Royal navy was called in to put a stop to boats from Iceland who were getting in the way of the British trawlers.

But something needs to be done.. Both Iceland and the Faroes have given themselves quotas which are way larger than five years ago. So… There may be sanctions, or there may be interference with boats and fishing operations, whatever is going to happen, “Cod War II” promises to be very interesting indeed.