Guest Writer

Beneath the Broken Ice: Playing with Mud

April 18, 2012April 18, 2012 Guest Writer

Science

Megumi Shimizu is a graduate student aboard the RVIB Nathaniel B. Palmer to collect sediment samples near Antarctic Peninsula as a part of the LARISSA project. She is interested in microorganisms and biogeochemistry of marine sediments; how the metabolism of microorganisms interact with the surrounding environment and the chemical components in sediments. See her first update here.

Are you playing with mud on the research vessel?

Some people on the ship joked when they saw me processing my sediment core. Yes, I’m playing with mud in Antarctica. Sampling sediments can tell us a lot, not only what happened across geologic time scales, but also what kind of organisms are living in the sediment, microbiology, and the geochemical conditions. We are serious about collecting mud and playing with mud.

upper panel: the entire view of glove box, lower panel: Liz Bucceri working on sediment sample processing in glove box. Photo by Megumi Shimizu

Nathaniel B. Palmer has three pieces of equipment to collect sediment; the megacore, kasten core, and jumbo piston core. The length you can reach below seafloor is different, 40cm, 1.5 to 6m and 24m respectively. Megacore is more suitable for biological studies since it preserves the sediment-water interface better than kasten core and jumbo piston core. Geological studies prefer Kasten core and jumbo piston core so that they can get older data from the sediment.

For my microbial lipid biomarker study, I’m taking samples from the megacore and kasten core. Along with microbial lipid and DNA, our team is collecting sediment and porewater (the water in pore spaces of sediments) to analyze geochemical properties of sediments, such as methane, sulfate, sulfide, and dissolved inorganic carbon. To maintain the condition of the sediments as close as the real environment, the sediment cores are processed under the condition of cold (~0C degree) and anoxic (no oxygen). How to make that condition? We have a special room called “The Little Antarctica”, on the ship, which is a big refrigerator containing glove box. A glove box is the transparent container with two pairs of gloves. The inside of the box is kept practically anoxic (less than 1% of oxygen. Atmospheric oxygen is ~20%).

Good intentions and negative transfer effects: The California swordfish fishery

March 13, 2012October 27, 2013 Guest Writer 25 Comments

Conservation, Science

Xiphias_gladius1 — Image courtesy Wikimedia Commons, via the National Marine Fisheries Service historic collection

A press release circulating on Twitter, which claims that a “deadly expansion” of a California fishery will negatively affect critically endangered leatherback sea turtles, has been making waves in the marine conservation and fisheries communities, inspiring a series of interesting discussions. Is it better to buy US-caught seafood with some bycatch than foreign-caught seafood from fleets with less strict environmental regulations? Is the current “Pacific leatherback conservation area”, a large region of the ocean where no fishing is allowed, too much of a restriction on U.S. fisheries? Can there be a balance between fisheries and conservation? I invited Jonathan Gonzalez, a California graphic designer with a strong interest in marine conservation issues, to write a guest post about the swordfish fishery in question. You can follow him on Twitter here, and he’s happy to answer your questions about this issue in the comments section of this post. In addition to his graphic design work, Jonathan has served as the assistant director of the Santa Barbara Marine Mammal center, and has worked with the California Shark Coalition to gather support from fishermen for the state’s recent ban on shark fins.

by Jonathan Gonzalez

Fisheries are complicated and often misunderstood. We often see conflicting information about what fish we should or should not eat and we see general statements about certain gear types that over simplify an extremely complex issue. But don’t be discouraged, learning about fisheries can be very fun and can lead to eating seafood with confidence, free of any guilt or confusion. One particular fishery I want to talk about that is not only complicated, but in my opinion it is California’s most misunderstood fishery. I’m talking about the drift gillnet (DGN) fishery for swordfish and common thresher sharks (CTS). Swordfish, CTS and mako sharks caught in Hawaiian set longlines are also landed in California, but I am not going to talk about that here. I am going to focus on the DGN fishery because this fishery has been in the headlines a bit lately because of recent motions that were voted on at a Pacific Fisheries Management Council (PFMC) meeting. Here is a press release you may have seen that in my opinion is full of factual errors and a few downright slanderous statements. I’m not going to point them all out and I’m not going to try to tell you what to do. Instead I am going to give you some background about the fishery and provide you with information that will hopefully help you to make an informed decision for yourself.

Beneath the Broken Ice: Megumi Shimizu on the 2012 LARISSA Campaign to the Antarctic Peninsula

March 12, 2012 Guest Writer 1 Comment

Science

Megumi Shimizu is a graduate student studying microorganisms in marine sediment. She is currently on board the RVIB Nathaniel B. Palmer exploring seafloor communities in a once ice-covered region beneath the Larsen Ice Shelf. Over the next month, she will be updating us from the field.

The RVIB Nathaniel B. Palmer. photo by Megumi Shimizu

I’m a PhD student interested in microorganisms and biogeochemistry of marine sediments; how the metabolisms of microorganisms interacting with the surrounding environment, the chemical components in sediments. Microorganisms in subseafloor are universally important because of its large biomass. It is said 50% of prokaryotes are living under the seafloor. This biomass makes large carbon and nutrients reservoir, which are important in biogeochemical cycle. For example, microorganisms play the role of organic carbon decomposition in sediments, as a result, carbon dioxide and methane are produced. In contrast, carbon dioxide and methane are also consumed by microorganisms called chemolithotrophs and methanotrophs in sediments. Therefore, understanding microorganisms in sediments; who they are, what are they doing, is important to reveal the details of global biogeochemical cycle and accurate estimate of budgets (amount of elements converted to different forms of chemicals for example, amount of carbon dioxide converted into organic carbon by carbon fixation). In addition, how microbial community response to environmental changes such as climate warming is also important in terms of the influence of global elemental cycles.

U.S. Ocean Policy Takes a (Small) Step Forward

January 12, 2012January 12, 2012 Guest Writer

Conservation

Earlier today, the National Ocean Council released a new Implementation Plan for the National Policy for the Stewardship of the Ocean, Our Coasts, and the Great Lakes. We asked our colleague Morgan Gopnik, formerly a senior advisor to the U.S. Commission on Ocean Policy, to summarize this new plan.

Today marks a momentous and long-awaited milestone for true ocean policy geeks: at noon the National Ocean Council released a draft Implementation Plan for the National Policy for the Stewardship of the Ocean, Our Coasts, and the Great Lakes! If this announcement makes you yawn, you are not alone. But wait! This new Plan could be truly significant for anyone who cares about ocean ecosystems and resources or coastal communities. Let me explain.

As most readers of Southern Fried Science probably know, the last decade has produced many depressing stories about declines in ocean health: overharvested fish stocks, waning biodiversity, “dead zones,” invasive species, oil spills, etc. It has also produced a number of studies and high-level Commission reports suggesting solutions to these problems, most notably the U.S. Commission on Ocean Policy’s “Ocean Blueprint for the 21^st Century,” released in September 2004. (Full disclosure: I served as Senior Advisor to the Commission.) The Blueprint provided lots of recommendations (212 in all) about controlling pollution, managing fisheries, protecting shorelines, and addressing other specific problems. But its major theme and most significant contribution was to emphasize the need to fundamentally change our approach to ocean management and governance.

Guest Post: A review of the Field Guide for Sharks of the Genus Carcharhinus

November 21, 2011December 9, 2011 Guest Writer

Science

Dr. David Ebert is the Director of the Pacific Shark Research Center at Moss Landing Marine Laboratories. He is one of the world’s leading experts on shark taxonomy, and has described new species of sharks, skates, rays, and chimaeras. Dr. Ebert has written over 100 publications, five books, and dozens of IUCN Red List assessments. He generously agreed to review a new taxonomy guide, Field Guide for Sharks of the Genus Carcharhinus, for Southern Fried Science. He has provided a thorough list of citations backing up his points, but all opinions are his own.

The shark genus Carcharhinus is one of the largest and perhaps most important genera of sharks, with many common and wide-ranging species. These sharks are mostly marine occurring from close inshore to the outer continental shelf and upper slope, but a few species inhabit estuaries and freshwater rivers and lakes. This group is by far one of the most important shark genera for fisheries globally, with various species being taken in commercial and sport fisheries, and in artisanal fisheries. Given the high profile and importance of this genus and the associated problems in identifying them to individual species in the field, an identification guide to the group would be most welcomed.

The book, “Field Guide for Sharks of the Genus Carcharhinus” by Matthias Voigt and Dietmar Weber, could have been that guide, with an exceptionally nice layout, beautiful illustrations, and tooth plates, but unfortunately the text does not stand up to the same high quality of the illustrations. The book cover is quite attractive and eye-catching, and upon initially thumbing through the illustrations and layout of the individual species accounts, I thought wow this looks to be an interesting and possibly useful guide to this shark group, even though I was unfamiliar with the authors, whom to be candid I had never heard of before.

Tagging Bull Sharks in the Neuse River

August 4, 2011August 4, 2011 Guest Writer 17 Comments

Science

Meagan Dunphy-Daly is a graduate student at the Duke University Marine Lab studying the effectiveness of marine reserves in protecting apex predators. She also has ongoing research examining bullshark/dolphin interactions in the Neuse River, NC, where she recently caught an 8 foot bullshark.

Well, it’s Shark Week and instead of heading up to the Neuse River to try to track bull sharks, I’m sitting in front of my computer staring at the marine forecast. Right now, we’re under a small craft advisory until tomorrow night and we’re all keeping our eyes on what Tropical Storm Emily is going to do over the weekend. Such is the ever-exciting life of a field biologist. Although there are a fair number of days spent in an office in front of a computer (be it checking the weather, entering data, or hoping that a manuscript will write itself), the days in the field are what make this job so sweet. I’m a graduate student in Dr. Andy Read’s Lab at Duke University and, in addition to my dissertation interest in the effectiveness of marine reserves for apex predators (think sharks, tuna, and billfish), I have the chance to carry out and participate in many other research projects in North Carolina and elsewhere (check out Reny Tyson’s previous posts on our trip to Antarctica). This summer, I’m studying bull shark habitat use in the Neuse River. Andrew joined us for a day of fieldwork last week and, although we didn’t catch a shark on this trip, we caught a big bull shark on the first day of our season the week before.

New Scaly-Foot Gastropod found in Indian Ocean

July 1, 2011July 4, 2011 Guest Writer 1 Comment

Science

Megumi Shimizu is a second year PhD student at the Duke University Marine Lab. Since the news has so far only been reported in Japanese, we asked her to provide a short write-up of the discovery. The first scaly-foot gastropod, Crysomallon squamiferum, was found in the Indian Ocean ten years ago (Van Dover et al 2001), … Read More “New Scaly-Foot Gastropod found in Indian Ocean” »

Shark Science Monday: The Sharks and Shark Fisheries of India

June 13, 2011October 27, 2013 Guest Writer 3 Comments

Science

Divya Karnad is a wildlife biologist in India focusing on marine issues. She began her career working with olive ridley sea turtles, studying hatchling responses to beach lighting and temperature-dependent sex determination. Lately, she has been focusing on marine fisheries issues on both coasts of India, including shark fishing and the fin trade. She met WhySharksMatter at the International Marine Conservation Congress, and agreed to write a guest post for Southern Fried Science.

A soupy end to Indian Sharks

Thomas and Arulsingh, fishermen who hail from Kanyakumari, hauled up their nets and fishing lines on a beach in southern India. The catch was special and I was privileged, as an outsider, to be invited to watch as this enormous fish was sliced, its fin, the most valuable part, handled with extreme care. The shark fin, I was told, would fetch a lot of money, despite the fact that it was not a hammerhead, which fetches the best price. Nevertheless, the fishermen revealed, there were several more where this one came from, and they could be caught easily using specialized hooks and lines. Altogether estimated to host about 70 species of shark, 18, including two species of hammerheads, spadenose, requiem and milk sharks, are often landed for fins or meat from Indian waters. Different parts of the Indian coast have different species compositions of sharks, with the northwest reporting large proportions of spadenose sharks, hammerheads along the south west coast, and requiem, hammerheads and milk sharks along the east coast. Sharks are usually brought to shore before finning and the flesh is consumed locally while the fins are exported to South-east Asian markets.

Update from Antarctica – What is MISHAP?

May 20, 2010May 20, 2010 Guest Writer 1 Comment

Science

Fresh from Antarctica, this update comes to us from Dr. Douglas Nowacek, one of the Principal Investigators for the MISHAP project, by way of our field correspondent, Reny Tyson. Follow along with their adventures at Tagging Whales in the Antarctic Seas.

MISHAP in Antarctica

May 7, 2010May 7, 2010 Guest Writer

Science

Southern Fried Notice: Reny Tyson is a graduate student at the Duke University Marine Lab currently on location in Antarctica tracking Humpback Whales. The main expedition blog is Tagging Whales in the Antarctic Seas hosted at the Nicholas School of the Environment. Follow their adventure as they track Humpbacks through Antarctic Seas. Today we begin … Read More “MISHAP in Antarctica” »