2,063 research outputs found

    Evidence and patterns of tuna spawning inside a large no-take marine protected area

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hernandez, C. M., Witting, J., Willis, C., Thorrold, S. R., Llopiz, J. K., & Rotjan, R. D. Evidence and patterns of tuna spawning inside a large no-take marine protected area. Scientific Reports, 9(1), (2019): 10772, doi:10.1038/s41598-019-47161-0.The Phoenix Islands Protected Area (PIPA), one of the world’s largest marine protected areas, represents 11% of the exclusive economic zone of the Republic of Kiribati, which earns much of its GDP by selling tuna fishing licenses to foreign nations. We have determined that PIPA is a spawning area for skipjack (Katsuwonus pelamis), bigeye (Thunnus obesus), and yellowfin (Thunnus albacares) tunas. Our approach included sampling larvae on cruises in 2015–2017 and using a biological-physical model to estimate spawning locations for collected larvae. Temperature and chlorophyll conditions varied markedly due to observed ENSO states: El Niño (2015) and neutral (2016–2017). However, larval tuna distributions were similar amongst years. Generally, skipjack larvae were patchy and more abundant near PIPA’s northeast corner, while Thunnus larvae exhibited lower and more even abundances. Genetic barcoding confirmed the presence of bigeye (Thunnus obesus) and yellowfin (Thunnus albacares) tuna larvae. Model simulations indicated that most of the larvae collected inside PIPA in 2015 were spawned inside, while stronger currents in 2016 moved more larvae across PIPA’s boundaries. Larval distributions and relative spawning output simulations indicated that both focal taxa spawned inside PIPA in all 3 study years, demonstrating that PIPA is protecting viable tuna spawning habitat.Funding and support was provided by the PIPA Trust, Waitt and Oceans5 Foundations, Sea Education Association, the Prince Albert of Monaco Foundation II, New England Aquarium, and Boston University to R.R. and J.W. C.H. was additionally supported by a National Science Foundation Graduate Research Fellowship. J.L. was additionally supported by NOAA through the Cooperative Institute for the North Atlantic Region (CINAR) under Cooperative Agreement NA14OAR4320158 in the form a CINAR Fellow Award, as well as by the WHOI Academic Programs Office. We thank A. Breef-Pilz for onboard sampling assistance, as well as S. Glancy, J. Pringle, E. Martin, J. Fisher, H. Goss, J. Jaskiel, S. Sheehan, and C. Moller for lab assistance. We thank the PIPA Trust and the PIPA Implementation Office for their support, as well as on-ship Kiribati Observers for their support and assistance: Tekeua Auatabu, Iannang Teaioro, Toaea Beiateuea, Taremon Korere, Kareati Waysang, and Moamoa Kabuati. We thank Q. Hanich for reading sections of this paper in advance. This research was conducted under Kiribati and PIPA permits PRP #s 3/17, 1/16, and 2/15 to JW

    Deep Sea Underwater Robotic Exploration in the Ice-Covered Arctic Ocean with AUVs

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    The Arctic seafloor remains one of the last unexplored areas on Earth. Exploration of this unique environment using standard remotely operated oceanographic tools has been obstructed by the dense Arctic ice cover. In the summer of 2007 the Arctic Gakkel Vents Expedition (AGAVE) was conducted with the express intention of understanding aspects of the marine biology, chemistry and geology associated with hydrothermal venting on the section of the mid-ocean ridge known as the Gakkel Ridge. Unlike previous research expeditions to the Arctic the focus was on high resolution imaging and sampling of the deep seafloor. To accomplish our goals we designed two new Autonomous Underwater Vehicles (AUVs) named Jaguar and Puma, which performed a total of nine dives at depths of up to 4062m. These AUVs were used in combination with a towed vehicle and a conventional CTD (conductivity, temperature and depth) program to characterize the seafloor. This paper describes the design decisions and operational changes required to ensure useful service, and facilitate deployment, operation, and recovery in the unique Arctic environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86060/1/ckunz-17.pd

    Use of the analysis of the volatile faecal metabolome in screening for colorectal cancer

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    Diagnosis of colorectal cancer is an invasive and expensive colonoscopy, which is usually carried out after a positive screening test. Unfortunately, existing screening tests lack specificity and sensitivity, hence many unnecessary colonoscopies are performed. Here we report on a potential new screening test for colorectal cancer based on the analysis of volatile organic compounds (VOCs) in the headspace of faecal samples. Faecal samples were obtained from subjects who had a positive faecal occult blood sample (FOBT). Subjects subsequently had colonoscopies performed to classify them into low risk (non-cancer) and high risk (colorectal cancer) groups. Volatile organic compounds were analysed by selected ion flow tube mass spectrometry (SIFT-MS) and then data were analysed using both univariate and multivariate statistical methods. Ions most likely from hydrogen sulphide, dimethyl sulphide and dimethyl disulphide are statistically significantly higher in samples from high risk rather than low risk subjects. Results using multivariate methods show that the test gives a correct classification of 75% with 78% specificity and 72% sensitivity on FOBT positive samples, offering a potentially effective alternative to FOBT
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