Researchers using radiocarbon dating have determined that Greenland sharks, slow-moving giants that live in the cold, dark waters of the North Atlantic, are the longest-living vertebrates on Earth, with one recorded as being 400 years old. Which explains the old Greenland shark quip that goes something like: “God must like practical jokes; why would He make […]
Followers of education writing and/or interested in crowdfunding stories may have noticed this one pop up this week: a university academic, Dr Alecia Bellgrove, who is raising money to fund research into edible seaweeds growing along the Victorian southwest coast.
She happens to be one of my Deakin marine biology lecturers (who I plan to interview on this topic as it heads closer to its funding target) and here’s a brief explanation of the research:
At a time when over 60% of adults and 25% of children in Australia are obese or overweight and the world is experiencing an unprecedented increase in atmospheric CO2 and associated climate change, there is compelling evidence from both the health and sustainability literature that seaweeds should become a common part of global diets.
Seaweeds are incredibly nutritious and can significantly reduce obesity and associated illnesses. Regular consumption of seaweeds thus has the potential to enhance the health of societies now, and for generations to come.
Seaweeds are incredibly efficient at photosynthesising and have amongst the highest rates of carbon fixation per unit area of any plants on the globe. The production of seaweeds for food and other commercial applications thus represents part of a viable solution for climate-change mitigation without compromising the availability of agricultural land and water resources into the future.
Southern Australia has the highest diversity of seaweeds globally with approximately 70% endemic to this region. The unique diversity of seaweeds on our shores represents a treasure chest of potential health and pharmaceutical benefits waiting to be opened. “But seaweed? Does it really taste any good?” I hear you ask. Well, millions of people in Asia think so; but this is a great question, and really important to assess when we are talking about the potential for new food products from the Australian marine flora.
With the $5250 requested we will be able to assess the taste preference of local (Victorian) seaweeds compared with seaweed from other parts of the world. We will do this by recruiting tasters and then cooking up a storm of local and imported seaweed delights to tempt their taste-buds. Funds will be used to lease a commercial kitchen, purchase ingredients and pay a research assistant to assist with the data collation.
There are also other important aspects to consider such as the nutritional value of the seaweeds and ecological sustainability of harvesting.
With additional funding beyond that requested we can also
1) examine the nutritional quality of local seaweeds, with comparisons to commercially available species and
2) estimate the local biomass of high-value, edible seaweeds and prospects for sustainable harvesting of wild populations.
Microscopic plankton (of the plant and animal variety) drives global carbon dioxide absorption. While the Amazon rainforest is absorbing nearly 2 billion tonnes of carbon per year, scientists have calculated the global ocean currently absorbs about one-third of carbon emissions but both carbon sinks can also be producers of carbon dioxide.
Researchers at the University of California (Irvine) have compared their survey data to 18 other marine voyages to find that plankton digest double the carbon previously calculated and overturning a 1934 science marine principle in the process:
Models of carbon dioxide in the world’s oceans need to be revised, according to new work by UC Irvine and other scientists published online Sunday in Nature Geoscience. Trillions of plankton near the surface of warm waters are far more carbon-rich than has long been thought, they found. Global marine temperature fluctuations could mean that tiny Prochlorococcus and other microbes digest double the carbon previously calculated. Carbon dioxide is the leading driver of disruptive climate change.
In making their findings, the researchers have upended a decades-old core principle of marine science known as the Redfield ratio, named for famed oceanographer Alfred Redfield. He concluded in 1934 that from the top of the world’s oceans to their cool, dark depths, both plankton and the materials they excrete contain the same ratio (106:16:1) of carbon, nitrogen and phosphorous.
But as any gardener who has done a soil test knows, amounts of those elements can vary widely. The new study’s authors found dramatically different ratios at a variety of marine locations. What matters more than depth, they concluded, is latitude. In particular, the researchers detected far higher levels of carbon in warm, nutrient-starved areas (195:28:1) near the equator than in cold, nutrient-rich polar zones (78:13:1).
“The Redfield concept remains a central tenet in ocean biology and chemistry. However, we clearly show that the nutrient content ratio in plankton is not constant and thus reject this longstanding central theory for ocean science,” said lead author Adam Martiny, associate professor of Earth system science and ecology & evolutionary biology at UC Irvine. “Instead, we show that plankton follow a strong latitudinal pattern.”
He and fellow investigators made seven expeditions to gather big jars of water from the frigid Bering Sea, the North Atlantic near Denmark, mild Caribbean waters and elsewhere. They used a sophisticated $1 million cell sorter aboard the research vessel to analyze samples at the molecular level. They also compared their data to published results from 18 other marine voyages.
Martiny noted that since Redfield first announced his findings, “there have been people over time putting out a flag, saying, ‘Hey, wait a minute.'” But for the most part, Redfield’s ratio of constant elements is a staple of textbooks and research. In recent years, Martiny said, “a couple of models have suggested otherwise, but they were purely models. This is really the first time it’s been shown with observation. That’s why it’s so important.”
Earlier this year I took part in one of the Deakin research projects dropping baited camera rigs in and near marine protected areas off the coast of Warrnambool, Victoria. It was a great experience – seeing how the dual-camera rigs are set up and deployed and then later viewing some of the footage of gummy sharks, seals and leatherjackets chewing at the bait bags – here’s a clip from the uni’s Youtube channel:
Yesterday was the first chance I’d had to get back on the boat, this time to the tourist-friendly area near the 12 Apostles and about 40 minutes by boat from Port Campbell. Richard, whose PhD revolves around the baited camera drops and counting, identifying and measuring the video-captured species, picked up two other students and I in the uni truck at 630am and we were on the water by 8.
While my earlier experience involved a lot of waiting, there was no time for hanging around on this trip – we had to make four drops of six camera rigs throughout the day, in slowly building swell with a cold front approaching. The 15kg rigs were also trickier to pull back into the boat from depths of 30-50m, as this charter outfit had a less powerful winch than previously used.
With a crew of six on board though, baiting and preparing the rigs was quicker and we were able to make the 24 drops in one day despite a few getting snagged temporarily while being winched up. Species we expect to see on the resulting footage include snapper, gummy sharks, flathead and leatherjacket, depending on the depth and location.
It will be very interesting to see how the biomass varies between drop locations inside and outside the marine park. Cray fishing operators often drop pots metres outside the marine park border, knowing the density of crays inside the park is greater than the heavily exploited sites further up and down the coast. And fishing boats steer clear of the reefs near the border, which should allow fish living in those areas to thrive.
More information on the Parks Victoria-funded research is available here.
By Emily Sohn
Between 700,000 and one million species live in the world’s oceans, according to a thorough new analysis, which also estimated that between one-third and two-thirds of those species have yet to be named and described.
The new numbers are far smaller than previous estimates, which had put the tally of marine species as high as 10 million or more. By coming up with a more accurate picture of what we know and what we don’t yet know about marine life, the study should help scientists better focus conservation efforts where they’re needed most.
“You can only love something if you know it,” says Ward Appeltans, a marine biologist at the Intergovernmental Oceanographic Commission of UNESCO in Oostende, Belgium. “We will not save the world with this result, but we may start understanding it better.”
The new findings also open up the possibility that we may eventually be able to identify just about every creature living in the sea.
“It may not be mission impossible to describe all the marine species in the ocean,” Appeltans says. “We are describing 2000 new marine species every year. If we can keep that momentum, we can start knowing exactly what’s living on our planet.”
In previous attempts to guess numbers of ocean species, scientists often made extrapolations based on rates of previous discoveries or numbers of unknown species in sample collections.
Those methods led to crude estimates that ranged from 300,000 to more than 10 million total species in the seas.
To come up with something more accurate, Appeltans worked with 120 of the world’s leading experts on specific groups of marine organisms.
Based on their intricate knowledge of taxonomy, the experts came up with educated guesses about numbers of known and unknown species in their own particular fields.
The study also employed a statistical model to incorporate expert assessments with known information about changes in rates of discovery over time.
Overall, the study counted about 400,000 described species of marine species, though about 40 percent of those had been described multiple times and had been given more than one scientific name. That led to a corrected tally of about 226,000 known marine species, the team reports today in the journal Current Biology.
The list includes about 200,000 animal species, 7600 plants and more than 1000 fungi.
Still yet to be found and described are between 482,000 and 741,000 species, the study found. Most of those are probably crustaceans, molluscs, phytoplankton and other small organisms. But the experts also predicted that science have yet to describe between two and eight species of whales and dolphins, along with 10 species of sea snakes and other reptiles.
Exact number not important
Besides the logistical achievement of coordinating the work of 120 scientists, the new study is a major step toward solving a basic mystery.
“The question of how many species there are is such a fundamental one and it’s a huge embarrassment that we don’t have the answer,” says Stuart Pimm, a conservation biologist at Duke University in Durham, North Carolina. “In a compelling way, this paper has come up with a fairly credible number for how much we know and don’t know.”
It’s not the exact number that’s particularly important, Pimm adds. Instead, simply having a number at all is what matters. Once we have a complete catalogue of species in the oceans, we can begin to figure out if we’re putting marine conservation areas in the right places or if environmental efforts need to be directed elsewhere.
“We know we’re losing biodiversity at a rate that is 1000 times faster than we should be, and if we’re going to stop that haemorrhaging of species, we have to know what the species are and most important, where they are,” says Pimm
always a problem when a headline is written without fully understanding the research: I speak from experience, having found out later that I’d done that several times! As Anthony Watts says, real data will always trump mathematical models but the issue remains that “Changes in ocean and climate systems could lead to smaller fish”.
From the University of British Columbia , a fish story inspired by a model:
Fish getting smaller as the oceans warm: UBC research
Changes in ocean and climate systems could lead to smaller fish, according to a new study led by fisheries scientists at the University of British Columbia.
The study, published today in the journal Nature Climate Change, provides the first-ever global projection of the potential reduction in the maximum size of fish in a warmer and less-oxygenated ocean.
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This is an amazing view from inside and around the world’s last remaining underwater science lab, Aquarius Reef Base.
Join the expedition at http://oneworldoneocean.org/aquarius —
On July 16 One World One Ocean will join Dr. Sylvia Earle, National Geographic Explorer-in-Residence, Liquid Pictures 3D, and a team of aquanauts for a 6-day expedition to a “research only” zone in Florida Keys National Marine Sanctuary, home to Aquarius, the last remaining underwater lab in the world. We will bring you live interviews and in-depth coverage.
Since 1993, America’s “inner space station” has helped us understand the disappearance of coral reefs, train NASA astronauts for space and research sea sponges, the source of two cancer drugs. The discoveries made at Aquarius have opened our eyes to how little we really know about the vast complexity of the ocean. It is one of the planet’s most important brain trusts, and it is about to be closed.
IMAX, RED, GoPro and DSLR cameras were used to capture the beauty of this special place.
Special thanks to:
The six camera rigs (one shown above) were set up with two cameras on different sized metal supports (to allow for readings of both sandy and rocky seafloor areas), with recording running for 60 minutes at a time. The light setup enabled the cameras to focus on the area around the bait pouches, where hopefully a variety of fish would congregate over the next hour.
Cameras were dropped inside marine parks and also within a 250m radius, as one of the funding bodies wanted data on counts for fish including sweep, snapper, bream and Australian salmon to analyse the effectiveness of marine park sanctuaries.
Over almost 10 hours on a local crayfish boat, another first-year and myself became proficient in baiting, dropping and retrieving the rigs while coping with some sizeable waves hitting the reefs near the inshore drop points. Then the next 45 minutes or so were spent learning as much as we could from the captain, a long-time crayfisherman, and Richard about the reasons for the research, how local crayfish quota system operates and the best local fishing and surfing spots.
It was also a good day to reflect on what I was doing at the same time two months ago – sitting at a desk in a steel and glass Melbourne CBD office building, wishing I was out on a boat somewhere looking at sealife like the friendly Australian fur seal below, who followed us for 40 minutes between drops.
The only difficulty we faced during the day occurred when one of the camera rig become wedged under a reef ledge, which called for a quick run back into the jetty to pick up snorkel gear and then a dive down 12 feet to shift the rig.
I don’t have any results to add here yet as Richard has another 30 hours of footage to analyse from yesterday’s drop but hope he’ll let me use a few minutes of footage soon. The water clarity should make for some interesting viewing, though the presence of three seals close to drop points during the trip may reduce the number of fish hanging around.
Overall it was a pretty fascinating look into a standard research trip, complete with the obstacles and sometimes boring downtime faced during a full day on the water.
A quick hi to anyone who reads this and thanks for dropping by. As my bio will no doubt say when I get that started, I’m studying marine biology as an undergrad as of March 2012!
So this blog will look at some of the projects we work on in the cool little coastal town of Warrnambool, Victoria (Australia) and beyond. Plus the side trips that may have nothing to do with science but still may be of interest.
To give you an idea of what I was doing before an abrupt life change led to studying marine science, check out my other blog, http://stevepog.blogspot.com Yeah I know, never got to fix that title but it’s all pretty much sports-focused and written when I was working in PR in the UK. While I still enjoy sport, doing PR in that field no longer holds much interest – obviously researching fish have been my passion so that’s where I’m heading!
Cheers and happy blogging, Stumbling or whatever else you get a kick out of.