Center for Marine Science

Marvin, NC, United States

Center for Marine Science

Marvin, NC, United States
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Stuercke B.,Center for Marine Science | Freshwater D.W.,Center for Marine Science
Botanica Marina | Year: 2010

Integrated morphological and molecular analyses of Polysiphonia species revealed that two western Atlantic species identified as P. denudata and P. urceolata (=P. stricta) represent undescribed taxa. Polysiphonia schneideri sp. nov. is proposed for specimens previously referred to P. denudata that are ecorticate and have six (5-7) pericentral cells, lateral branches that arise in the axils of trichoblasts, rhizoids cutoff from pericentral cells, trichoblasts irregularly arranged and not on every segment, spermatangial stichidia forming as a furcation of trichoblasts, and tetrasporangia arranged in straight series. Polysiphonia kapraunii sp. nov. is proposed for specimens previously referred to P. urceolata (=P. stricta) that are ecorticate and have four pericentral cells, lateral branches that replace trichoblasts, rhizoids in open connection with pericentral cells, trichoblasts irregularly arranged and not on every segment, spermatangial stichidia forming as a furcation of trichoblasts, and tetrasporangia arranged in straight series. Phylogenetic analyses of rbcL show that the newly described species are unique and clearly distinct from the species with which they had previously been identified. © 2010 by Walter de Gruyter Berlin New York 2010.

Pratchett M.S.,James Cook University | McCowan D.,James Cook University | Maynard J.A.,CNRS Insular Research Center and Environment Observatory | Maynard J.A.,Center for Marine Science | And 2 more authors.
PLoS ONE | Year: 2013

Background:Climate-induced coral bleaching poses a major threat to coral reef ecosystems, mostly because of the sensitivities of key habitat-forming corals to increasing temperature. However, susceptibility to bleaching varies greatly among coral genera and there are likely to be major changes in the relative abundance of different corals, even if the wholesale loss of corals does not occur for several decades. Here we document variation in bleaching susceptibility among key genera of reef-building corals in Moorea, French Polynesia, and compare bleaching incidence during mass-bleaching events documented in 1991, 1994, 2002 and 2007. Methodology/Principal Findings:This study compared the proportion of colonies that bleached for four major genera of reef-building corals (Acropora, Montipora, Pocillopora and Porites), during each of four well-documented bleaching events from 1991 to 2007. Acropora and Montipora consistently bleached in far greater proportions (up to 98%) than Pocillopora and Porites. However, there was an apparent and sustained decline in the proportion of colonies that bleached during successive bleaching events, especially for Acropora and Montipora. In 2007, only 77% of Acropora colonies bleached compared with 98% in 1991. Temporal variation in the proportion of coral colonies bleached may be attributable to differences in environmental conditions among years. Alternately, the sustained declines in bleaching incidence among highly susceptible corals may be indicative of acclimation or adaptation.Conclusions/Significance:Coral genera that are highly susceptible to coral bleaching, and especially Acropora and Montipora, exhibit temporal declines in their susceptibility to thermal anomalies at Moorea, French Polynesia. One possible explanation for these findings is that gradual removal of highly susceptible genotypes (through selective mortality of individuals, populations, and/or species) is producing a coral assemblage that is more resistant to sustained and ongoing ocean warming. © 2013 Pratchett et al.

Vignaud T.,CNRS Insular Research Center and Environment Observatory | Clua E.,Direction Regionale Recherche et Technology | Mourier J.,CNRS Insular Research Center and Environment Observatory | Maynard J.,CNRS Insular Research Center and Environment Observatory | And 2 more authors.
PLoS ONE | Year: 2013

The population dynamics of shark species are generally poorly described because highly mobile marine life is challenging to investigate. Here we investigate the genetic population structure of the blacktip reef shark (Carcharhinus melanopterus) in French Polynesia. Five demes were sampled from five islands with different inter-island distances (50-1500 km). Whether dispersal occurs between islands frequently enough to prevent moderate genetic structure is unknown. We used 11 microsatellites loci from 165 individuals and a strong genetic structure was found among demes with both F-statistics and Bayesian approaches. This differentiation is correlated with the geographic distance between islands. It is likely that the genetic structure seen is the result of all or some combination of the following: low gene flow, time since divergence, small effective population sizes, and the standard issues with the extent to which mutation models actually fit reality. We suggest low levels of gene flow as at least a partial explanation of the level of genetic structure seen among the sampled blacktip demes. This explanation is consistent with the ecological traits of blacktip reef sharks, and that the suitable habitat for blacktips in French Polynesia is highly fragmented. Evidence for spatial genetic structure of the blacktip demes we studied highlights that similar species may have populations with as yet undetected or underestimated structure. Shark biology and the market for their fins make them highly vulnerable and many species are in rapid decline. Our results add weight to the case that total bans on shark fishing are a better conservation approach for sharks than marine protected area networks. © 2013 Vignaud et al.

McCall J.R.,Center for Marine Science | Elliott E.A.,Center for Marine Science | Bourdelais A.J.,Center for Marine Science
Marine Drugs | Year: 2014

Brevetoxins are a family of ladder-framed polyether toxins produced during blooms of the marine dinoflagellate, Karenia brevis. Consumption of shellfish or finfish exposed to brevetoxins can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are believed to be due to the activation of voltage-sensitive sodium channels in cell membranes. The traditional cytotoxicity assay for detection of brevetoxins uses the Neuro-2A cell line, which must first be treated with the neurotoxins, ouabain and veratridine, in order to become sensitive to brevetoxins. In this study, we demonstrate several drawbacks of the Neuro-2A assay, which include variability for the EC50 values for brevetoxin and non-linear triphasic dose response curves. Ouabain/ veratridine-treated Neuro-2A cells do not show a typical sigmoidal dose response curve in response to brevetoxin, but rather, have a polynomial shaped curve, which makes calculating EC50 values highly variable. We describe a new fluorescence live cell imaging model, which allows for accurate calculation of cytotoxicity via nuclear staining and additional measurement of other viability parameters depending on which aspect of the cell is stained. In addition, the SJCRH30 cell line shows promise as an alternative to Neuro-2A cells for testing brevetoxins without the need for ouabain and veratridine. © 2014 by the authors; licensee MDPI.

van der Merwe P.,University of Tasmania | Lannuzel D.,University of Tasmania | Lannuzel D.,Center for Marine Science | Bowie A.R.,University of Tasmania | And 3 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2011

Iron is a fundamental nutrient limiting phytoplankton growth in vast regions of the Southern Ocean. Sea ice, which covers ~80% of the Southern Ocean (south of 60°S) during maximum extent, can concentrate iron up to two orders of magnitude higher than in the underlying sea water. The fractionation of iron between the particulate and dissolved fractions depends on the location and type of sea-ice formation and can impact on the bioavailability of this important trace element. This study is the first to document iron fractionation and concentration in both pack and fast ice during a single research study. Sampling was from within the 110-130°E sector of Antarctica. We observed markedly higher concentrations of particulate iron at our fast-ice site (0.96-214. nM) relative to several pack-ice sites (0.87-77.7. nM). A high particulate-to-dissolved iron ratio was observed at the fast-ice site (285:1) relative to the highest observed in pack ice (23:1). This suggests a decoupling between the sources and/or sinks of the dissolved and particulate fractions. Preferential release of dissolved iron (and not particulate iron) into brines at all sites sampled with the sack hole method (and therefore indicative of brine drainage) indicates the diffuse nature of the dissolved fraction. Furthermore, this indicates that there may be a temporal decoupling between the release of the dissolved and the particulate fractions into the water column as sea ice becomes more permeable during the seasonal melt. Implications for phytoplankton production in Antarctic sea ice are discussed. © 2010 Elsevier Ltd.

Mamoozadeh N.R.,Center for Marine Science | Freshwater D.W.,Center for Marine Science
Botanica Marina | Year: 2011

Molecular-assisted identification using plastid-encoded rbcL and mitochondrion-encoded COI loci identified five species of Polysiphonia sensu lato from 16 Florida and Caribbean Mexico samples. Morphological character states were examined and used to identify these species as Neosiphonia bajacali comb. nov., N. echinata comb. nov., N. sphaerocarpa, N. tepida, and Polysiphonia anomala. Descriptions are provided and the phylogenetic relationships of the five species were determined through maximum likelihood analyses of rbcL and nuclear-encoded SSU sequence data. Neosiphonia bajacali and N. echinata had a combination of character states described for Neosiphonia: rhizoids cut-off from pericentral cells, lateral branch or trichoblast initials on every segment in a spiral pattern, tetrasporangia in spiral series, and spermatangial stichidia developing as bifurcations of trichoblasts, and these new combinations are proposed. Examination of N. echinata, P. fracta and North Carolina specimens identified as P. breviarticulata revealed no significant morphological differences. Polysiphonia fracta is proposed as a synonym of N. echinata and the presence of P. breviarticulata within the western Atlantic is questioned. This is the first report of N. bajacali from the Caribbean and the first report of N. echinata from Caribbean Mexico. © 2011 by Walter de Gruyter Berlin Boston.

Barreto F.S.,Center for Marine Science | Barreto F.S.,University of California at San Diego | Tomas C.R.,Center for Marine Science | McCartney M.A.,Center for Marine Science
Journal of Heredity | Year: 2011

Due to slow rates of molecular evolution, DNA sequences used to identify and build phylogenies of algal species involved in harmful algal blooms (HABs) are generally invariant at the intraspecific level. This means that it is unknown whether HAB events result from the growth of a single clone, a few dominant clones, or multiple clones. This is true despite the fact that several physiological and demographic traits, as well as toxicity, are known to vary across clones. We generated AFLP fingerprints from a set of 6 clonal isolates, taken from a bloom of Prymnesium parvum at a striped bass mariculture facility. This new haptophyte bloom was recently implicated in fish kills at several sites in the United States. The AFLP fragments were highly reproducible and showed that all isolates were distinguishable due to abundant AFLPs unique to single isolates. These results demonstrate that blooms can be genetically diverse outbreaks and indicate that AFLP can be a powerful molecular tool for characterizing and monitoring this diversity. © 2011 The American Genetic Association. All rights reserved.

Van Hooidonk R.,National Oceanic and Atmospheric Administration | Van Hooidonk R.,University of Miami | Maynard J.A.,CNRS Insular Research Center and Environment Observatory | Maynard J.A.,Center for Marine Science | And 3 more authors.
Global Change Biology | Year: 2014

Coral reefs and the services they provide are seriously threatened by ocean acidification and climate change impacts like coral bleaching. Here, we present updated global projections for these key threats to coral reefs based on ensembles of IPCC AR5 climate models using the new Representative Concentration Pathway (RCP) experiments. For all tropical reef locations, we project absolute and percentage changes in aragonite saturation state (Ωarag) for the period between 2006 and the onset of annual severe bleaching (thermal stress >8 degree heating weeks); a point at which it is difficult to believe reefs can persist as we know them. Severe annual bleaching is projected to start 10-15 years later at high-latitude reefs than for reefs in low latitudes under RCP8.5. In these 10-15 years, Ωarag keeps declining and thus any benefits for high-latitude reefs of later onset of annual bleaching may be negated by the effects of acidification. There are no long-term refugia from the effects of both acidification and bleaching. Of all reef locations, 90% are projected to experience severe bleaching annually by 2055. Furthermore, 5% declines in calcification are projected for all reef locations by 2034 under RCP8.5, assuming a 15% decline in calcification per unit of Ωarag. Drastic emissions cuts, such as those represented by RCP6.0, result in an average year for the onset of annual severe bleaching that is ~20 years later (2062 vs. 2044). However, global emissions are tracking above the current worst-case scenario devised by the scientific community, as has happened in previous generations of emission scenarios. The projections here for conditions on coral reefs are dire, but provide the most up-to-date assessment of what the changing climate and ocean acidification mean for the persistence of coral reefs. © 2013 John Wiley & Sons Ltd.

Understanding the biosynthesis of dinoflagellate polyketides presents many unique challenges. Because of the remaining hurdles to dinoflagellate genome sequencing, precursor labeling studies remain the only viable way to investigate dinoflagellate biosynthesis. However, prior studies have shown that polyketide chain assembly does not follow any of the established processes. Additionally, acetate, the common precursor for polyketides, is frequently scrambled, thus compromising interpretation. These factors are further compounded by low production yields of the compounds of interest. A recent report on the biosynthesis of spirolides, a group belonging to the growing class of toxic spiroimines, provided some insight into the polyketide assembly process based on acetate labeling studies, but many details were left uncertain. By feeding (13)C methyl-labeled methionine to cultures of Alexandrium ostenfeldii, the producing organism of 13-desmethylspirolide C, and application of the odd-even methylation rule, the complete biosynthetic pathway has been established.

News Article | February 27, 2017

The 35th Annual Whale Festival on March 18 and 19 in Fort Bragg, California is a perfect time to catch the migration of the Pacific Gray Whale from Baja to their ancestral feeding grounds in the Bering Sea—as many as 20,000 whales pass by the Mendocino Coast twice each year—heading south between December and February and north from February until April. Visitors can whale watch from miles of beaches, including the new Coastal Trail in Fort Bragg, enjoy a chowder contest where local restaurants compete (a ticket to the event entitles visitors to cast their vote for the best chowder of the year), and a craft beer tasting offered by local North Coast Brewing Company, both at Town Hall. Following those events, it's time to sample a variety of award winning Anderson Valley wines and hors d'oeuvres while visiting local shops and inns. Tickets can be bought online for the chowder, wine, and beer tasting. Visit for details. “We’re very excited about the 35th Annual Whale Festival this year" says Mendocino Coast Chamber of Commerce CEO Sharon Davis, "we’ve got award-winning Anderson Valley wines, local chefs creating amazing chowders for the contest, and North Coast Brewing Company pouring North Coast Steller IPA, and sharing proceeds from sales for marine mammal research. The Whale Festival is a perfect example of our community coming together to celebrate these majestic creatures while having a great time!" A variety of other events are scheduled in Fort Bragg throughout the weekend, including a Whale Walk and Run, a Beer and Barbeque Festival, and educational activities with the Noyo Center for Marine Science, the Mendocino Area Parks Association, and Golden Gate Cetacean Research biologists. MacKerricher State Park is one of the best locations for watching the gray whale migration. A wheelchair-accessible boardwalk leads to the headlands of Laguna Point for a spectacular, panoramic view of a pristine, rugged stretch of coastline where sightings of whale tails or whales breaching are common phenomena. On Saturday, March 18, a guided whale walk led by park staff and volunteer docents along the coastal South trail begins at 11:00 a.m. at the Visitor Center. Saturday afternoon activities for families focus on arts and crafts, games, and interactive learning at education stations. Kids can build a badge of whale knowledge, play games, make art, listen to music, and enjoy a free hot dog lunch. On Sunday, March 19th from 1:00 to 3:00 p.m. visitors will have a chance to learn how to help preserve a whale skeleton. Learning opportunities will continue on Sunday, March 19 with a Science and Art Fair from 10:00 a.m - 4:00 p.m., and a talk in Town Hall: Bottlenose Dolphins and Harbor Porpoises by Golden Gate Cetacean Research biologists Bill Keener and Jon Stern from 4:00- 5:30 p.m. in Town Hall. What to watch for when scanning the ocean for whales: Spout: a visible exhalation expelled under pressure from the blowhole (paired nostrils) Up to 10 feet high Pattern of Blows: Occurs 3 to 5 times at 10-20 second intervals Pods: Groups of 3 to 8 individuals. Look for spouts happening together Sounding: As the whale dives deep, ridges may be seen on its back Flukes: The fluke, or tail fin might be seen as the whale sounds Spy-Hopping: The head is raised above water to allow the whale to look around Breaching: Whales jump clear of water, and fall back with a huge splash Whale watching boats are also a great way to observe the huge mammals at close range If visiting earlier in the month, related events include the Mendocino Whale Festival on March 4 and 5 and the Little River Whale Festival on March 11 and 12. Information and updates for all three Whale Festival weekends is available at and on the Mendocino Coast Chamber of Commerce MendoWhale Facebook page.

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