Life Sciences Commons^™

Oysters And Eelgrass: Potential Partners In A High Pco2 Ocean, Maya L. Groner, Colleen A. Burge, Ruth Cox, Natalie D. Rivlin, Mo Turner, Kathryn L. Van Alstyne Dr., Sandy Wyllie-Echeverria, John Bucci, Philip Staudigel, Carolyn S. Friedman

Shannon Point Marine Center Faculty Publications

Ocean acidification (OA) threatens calcifying organisms such as the Pacific oyster, Crassostrea gigas. In contrast, eelgrass, Zostera marina, can benefit from the increase in available carbon for photosynthesis found at a lower seawater pH. Seagrasses can remove dissolved inorganic carbon from OA environments, creating local daytime pH refugia. Pacific oysters may improve the health of eelgrass by filtering out pathogens such as Labyrinthula zosterae, which causes eelgrass wasting disease (EWD). Using a laboratory experiment, we found that co-culture of eelgrass with oysters reduced the severity of EWD. EWD was also reduced in more acidic waters, which negatively …

Estimating Variation In Surface Emissivities Of Intertidal Macroalgae Using An Infrared Thermometer And The Effects On Temperature Measurements, Kathryn L. Van Alstyne Dr., Theresa K. Olson

Shannon Point Marine Center Faculty Publications

Accurate measurements of surface temperatures with an infrared (IR) thermometer require input of the emissivities of the surfaces being measured; however, few determinations of the emissivities of intertidal organisms’ surfaces have been made. Emissivities of intertidal macroalgae were measured to determine whether algal species, measurement angle, hydration, and layering affected them. Emissivities were similar and averaged 0.94 among 11 of 13 species. The species with lower and more variable emissivities (Chondracanthus exasperatus and Desmarestia viridis) differed in morphology from the other species, which were relatively flat thin blades with little surface texture. Measurement angle caused emissivities to decrease …

Sulfur Isotope Variability Of Oceanic Dmsp Generation And Its Contributions To Marine Biogenic Sulfur Emissions, Kathryn L. Van Alstyne Dr., Harry Oduro, James Farquhar

Shannon Point Marine Center Faculty Publications

Oceanic dimethylsulfoniopropionate (DMSP) is the precursor to dimethylsulfide (DMS), which plays a role in climate regulation through transformation to methanesulfonic acid (MSA) and nonseasalt sulfate (NSS-SO₄ ²⁻) aerosols. Here, we report measurements of the abundance and sulfur isotope compositions of DMSP from one phytoplankton species (Prorocentrum minimum) and five intertidal macroalgal species (Ulva lactuca, Ulva linza, Ulvaria obscura, Ulva prolifera, and Polysiphonia hendryi) in marine waters. We show that the sulfur isotope compositions (δ³⁴S) of DMSP are depleted in ³⁴S relative to the source seawater sulfate by ~1–3‰ and are …

Larval Dispersal: Vent Life In The Water Column, Diane K. Adams, Shawn M. Arellano, Breea Govenar

Shannon Point Marine Center Faculty Publications

Visually striking faunal communities of high abundance and biomass cluster around hydrothermal vents, but these animals don’t spend all of their lives on the seafloor. Instead, they spend a portion of their lives as tiny larvae in the overlying water column. Dispersal of larvae among vent sites is critical for population maintenance, colonization of new vents, and recolonization of disturbed vents. Historically, studying larvae has been challenging, especially in the deep sea. Advances in the last decade in larval culturing technologies and more integrated, interdisciplinary time-series observations are providing new insights into how hydrothermal vent animals use the water column …

Rebuilding A Vent Community: Lessons From The Epr Integrated Study Site, Breea Govenar, Shawn Arellano, Diane K. Adams

Shannon Point Marine Center Faculty Publications

The discovery of a seafloor eruption at the East Pacific Rise (EPR ) in 1991 presented an opportunity to examine the colonization and assembly of macrofaunal communities at newly formed diffuse-flow vents as well as to document the changes in community composition (Shank et al., 1998) in the context of temperature variation (Scheirer et al., 2006) and fluid chemistry (Von Damm and Lilley, 2004). The eruption site became a focus of the Ridge 2000 EPR Integrated Study Site (ISS) established to facilitate studies of the interaction of biological, geochemical, and/or physical processes associated with seafloor spreading. A second seafloor eruption …

Toward An Understanding Of The Molecular Mechanisms Of Barnacle Larval Settlement: A Comparative Transcriptomic Approach, Zhang-Fan Chen, Kiyotaka Matsumura, Hao Wang, Shawn M. Arellano, Xingcheng Yan, Intikhab Alam, John A.C. Archer, Vladimir B. Bajic, Pei-Yuan Qian

Shannon Point Marine Center Faculty Publications

Background: The barnacle Balanus amphitrite is a globally distributed biofouler and a model species in intertidal ecology and larval settlement studies. However, a lack of genomic information has hindered the comprehensive elucidation of the molecular mechanisms coordinating its larval settlement. The pyrosequencing-based transcriptomic approach is thought to be useful to identify key molecular changes during larval settlement.

Methodology and Principal Findings: Using 454 pyrosequencing, we collected totally 630,845 reads including 215,308 from the larval stages and 415,537 from the adults; 23,451 contigs were generated while 77,785 remained as singletons. We annotated 31,720 of the 92,322 predicted open reading frames, which …

Variability In Protist Grazing And Growth On Different Marine Synechococcus Isolates, Jude K. Apple, Suzanne L. Strom, Brian Palenik, Bianca Brahamsha

Shannon Point Marine Center Faculty Publications

Grazing mortality of the marine phytoplankton Synechococcus is dominated by planktonic protists, yet rates of consumption and factors regulating grazer-Synechococcus interactions are poorly understood. One aspect of predator-prey interactions for which little is known are the mechanisms by which Synechococcus avoids or resists predation and, in turn, how this relates to the ability of Synechococcus to support growth of protist grazer populations. Grazing experiments conducted with the raptorial dinoflagellate Oxyrrhis marina and phylogenetically diverse Synechococcus isolates (strains WH8102, CC9605, CC9311, and CC9902) revealed marked differences in grazing rates-specifically that WH8102 was grazed at significantly lower rates than all …

Dependency On De Novo Protein Synthesis And Proteomic Changes During Metamorphosis Of The Marine Bryozoan Bugula Neritina, Yue Him Wong, Shawn M. Arellano, Huoming Zhang, Timothy Ravasi, Pei-Yuan Qian

Shannon Point Marine Center Faculty Publications

Background: Metamorphosis in the bryozoan Bugula neritina (Linne) includes an initial phase of rapid morphological rearrangement followed by a gradual phase of morphogenesis. We hypothesized that the first phase may be independent of de novo synthesis of proteins and, instead, involves post-translational modifications of existing proteins, providing a simple mechanism to quickly initiate metamorphosis. To test our hypothesis, we challenged B. neritina larvae with transcription and translation inhibitors. Furthermore, we employed 2D gel electrophoresis to characterize changes in the phosphoproteome and proteome during early metamorphosis. Differentially expressed proteins were identified by liquid chromatography tandem mass spectrometry and their gene expression …

Spawning, Development, And The Duration Of Larval Life In A Deep-Sea Cold-Seep Mussel, Shawn M. Arellano, Craig M. Young

Shannon Point Marine Center Faculty Publications

We describe culturing techniques and development for the cold-seep mussel “Bathymodiolus” childressi, the only deep-sea bivalve for which development has been detailed. Spawning was induced in mature mussels by injection of 2 mmol l⁻¹ serotonin into the anterior adductor muscle. The mean egg diameter is 69.15 ± 2.36 μm (±S.D.; n = 50) and eggs are negatively buoyant. Cleavages are spiral and at 7–8 °C occur at a rate of one per 3–9 h through hatching, with free-swimming blastulae hatching by 40 h and shells beginning to develop by day 12. When temperature was raised to 12–14 °C …

Ecological And Physiological Controls Of Species Composition In Green Macroalgal Blooms, Kathryn L. Van Alstyne Dr., Timothy A. Nelson, Karalon Haberlin, Amorah V. Nelson, Heather Ribarich, Ruth Hotchkiss, Lee Buckingham, Dejah J. Simunds, Kerri Fredrickson

Shannon Point Marine Center Faculty Publications

Green macroalgal blooms have substantially altered marine community structure and function, specifically by smothering seagrasses and other primary producers that are critical to commercial fisheries and by creating anoxic conditions in enclosed embayments. Bottom-up factors are viewed as the primary drivers of these blooms, but increasing attention has been paid to biotic controls of species composition. In Washington State, USA, blooms are often dominated by Ulva spp. intertidally and Ulvaria obscura subtidally. Factors that could cause this spatial difference were examined, including competition, grazer preferences, salinity, photoacclimation, nutrient requirements, and responses to nutrient enrichment. Ova specimens grew faster than …

The Distribution Of Dmsp In Green Macroalgae From Northern New Zealand, Eastern Australia And Southern Tasmania, Kathryn L. Van Alstyne Dr.

Shannon Point Marine Center Faculty Publications

The sulphonium compound diinethylsulphoniopropionate (DMSP) is commonly found in temperate green macroalgae. To examine taxonomic and regional and local geographical patterns of DMSP production in Australasian algae, I collected 30 species of green algae from 14 sites in three regions, eastern Australia, Tasmania, Australia, and the North Island of New Zealand. The distribution of DMSP content was similar to that seen from other areas of the world. DMSP was found in high concentrations in Ulva and Codium spp. It tended to be undetectable or in lower concentrations in other members of the orders Bryopsidales and Cladophorales. There was …

Dimethylsulfide Release During Macroinvertebrate Grazing And Its Role As An Activated Chemical Defense, Kathryn L. Van Alstyne Dr., Letise T. Houser

Shannon Point Marine Center Faculty Publications

Almost half the biogenic sulfur emitted globally originates as dimethylsulfide (DMS) in marine algae. Yet, despite its importance to climate and the global sulfur cycle, the reasons why many diverse algal taxa produce DMS remain unclear. DMS is produced when dimethylsulfoniopropionate (DMSP) is cleaved by the enzyme DMSP lyase into DMS and acrylic acid. Because acrylic acid can deter feeding by some herbivores, the production of DMSP has been postulated to be part of an antiherbivore chemical defense system, with DMS being a by-product of the production of the defensive compound acrylic acid. However, we found that DMS plays a …

The Effects Of Salinity On Dimethylsulfoniopropionate Production In The Green Alga Ulva Fenestrata Postels Et Ruprecht (Chlorophyta), Kathryn L. Van Alstyne Dr., Karen N. Pelletreau, Karyna Rosario

Shannon Point Marine Center Faculty Publications

Dimethylsulfoniopropionate (DMSP) in marine algae has been hypothesized to serve as a compatible solute which functions in osmotic acclimation or cryoprotection. However, many macroalgae that produce large quantities of DMSP live in habitats where they are unlikely to experience large fluctuations in salinities or freezing temperatures.We hypothesized that DMSP has other functions in these algae and that they should not show large changes in DMSP concentrations in response to salinity changes.We tested this hypothesis by placing 1.5 cm² diameter disks of the chlorophyte Ulva fenestrata in artificial seawater (ASW) at salinities from 10% ASW to 300% ASW. Over the …

Activated Defense Systems In Marine Macroalgae: Evidence For An Ecological Role For Dmsp Cleavage, Kathryn L. Van Alstyne Dr., Gordon V. Wolfe, Tess L. Freidenburg, Anna Neill, Corrine Hicken

Shannon Point Marine Center Faculty Publications

Activated defenses against herbivores and predators are defenses whereby a precursor compound is stored in an inactive or mildly active form. Upon damage to the prey, the precursor is enzymatically converted to a more potent toxin or feeding deterrent. In marine systems, activated defenses are only known to exist in a few species of tropical macroalgae. In this study, we examined an activated defense system in temperate marine macroalgae in which the osmolyte dimethylsulfo- niopropionate (DMSP) is converted to acrylic acid or acrylate, depending upon the pH, and dimethyl sulfide (DMS) by the enzyme DMSP lyase upon damage to the …

Effects Of Nutrient Enrichment On Growth And Phlorotannin Production In Fucus Gardneri Embryos, Kathryn L. Van Alstyne Dr., Karen N. Pelletreau

Shannon Point Marine Center Faculty Publications

Resource-allocation models predict trade-offs between growth and chemical defense. The carbon/nutrient balance hypothesis (CNBH) predicts that plants will allocate carbon to growth when nutrients are abundant and allocate it to carbon-based antiherbivore defenses when nutrients are limiting. In marine systems, field and laboratory tests of the CNBH with phlorotannin-producing algae have generally supported the predictions of the model. However, these tests have all measured phlorotannin concentrations in adult algae rather than juveniles, which are susceptible to higher

Herbivore Grazing Increases Polyphenolic Defenses In The Intertidal Brown Alga Fucus Distichus, Kathryn L. Van Alstyne Dr.

Shannon Point Marine Center Faculty Publications

Although predator-induced defenses have been reported for several species of terrestrial vascular plants, they have not been previously described in aquatic or nonvascular plants. In this study, field manipulations were used to demonstrate the presence of inducible chemical defense production in the intertidal brown alga Fucus distich us. When experimentally damaged, Fucus increased its concentrations of polyphenolic compounds by ≈20% over uninjured control plants within 2 wk. These increases occurred in the area where the plant was injured and within adjacent undamaged branches. The increase in concentrations of polyphenolic compounds in clipped plants in these experiments corresponded well with differences …

Effects Of Phytoplankton Taste And Smell On Feeding Behavior Of The Copepod Centropages Hamatus, Kathryn L. Van Alstyne Dr.

Shannon Point Marine Center Faculty Publications

Adult copepods Centropages hamatus were induced to feed on 10 to 40 µm Sephadex beads by adding Thalassiosira weissflogii or Scrippsiella trochoidea whole­-cell extract, or filtrate from a T. weiss flogii culture , to a bead suspension. Beads were neither ingested in the absence of a chemical stimulus, nor in the presence of filtrates from cultures of S. trochoidea and Olisthodiscus luteus , or 0. luteus extracts. Extracts from both S. trochoidea and 0. luteus, and filtrate from an 0. luteus culture, appear to exert an inhibitory …