This page has only limited features, please log in for full access.

Unclaimed
C. J. Gobler
School of Marine and Atmospheric Sciences, Stony Brook University, Southampton NY, United States

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 01 May 2021 in Harmful Algae
Reads 0
Downloads 0

Alexandrium catenella is a harmful algal bloom (HAB)-forming dinoflagellate that causes significant damage to the cultivation and harvest of shellfish due to its synthesis of paralytic shellfish toxins. To evaluate the potential for macroalgae aquaculture to mitigate A. catenella blooms, we determined the effects of three cultivable macroalgae - Saccharina latissima (sugar kelp), Chondrus crispus (Irish moss), and Ulva spp. - on A. catenella in culture- and field-based experiments. Co-culture growth assays of A. catenella exposed to environmentally realistic concentrations of each macroalgae showed that all species except low levels of C. crispus caused cell lysis and significant reductions in A. catenella densities relative to control treatments of 17–74% in 2–3 days and 42–96% in ~one week (p<0.05 for all assays). In a toxin accumulation experiment, S. latissima significantly lessened (p<0.05) saxitoxin (STX) accumulation in blue mussels (Mytilus edulis), keeping levels (71.80±1.98 µg STX 100 g−1) below US closure limits (80 µg STX 100 g−1) compared to the untreated control (93.47±8.11 µg STX 100 g−1). Bottle incubations of field-collected, bloom populations of A. catenella experienced significant reductions in cell densities of up to 95% when exposed to aquaculture concentrations of all three macroalgae (p<0.005 for all). The stocking of aquacultured S. latissima within mesocosms containing a bloom population of A. catenella (initial density: 3.2 × 104 cells L−1) reduced the population of A. catenella by 73% over 48 h (p<0.005) while Ulva addition caused a 54% reduction in A. catenella over 96 h (p Ulva spp. > C. crispus. Seaweeds’ primary anti-A. catenella activity were allelopathic, while nutrient competition, pH elevation, and macroalgae-attached bacteria may have played a contributory role in some experiments. Collectively, these results suggest that the integration of macroalgae with shellfish-centric aquaculture establishments should be considered as a non-invasive, environmentally friendly, and potentially profit-generating measure to mitigate A. catenella-caused damage to the shellfish aquaculture industry.

ACS Style

Peter H. Sylvers; Christopher J. Gobler. Mitigation of harmful algal blooms caused by Alexandrium catenella and reduction in saxitoxin accumulation in bivalves using cultivable seaweeds. Harmful Algae 2021, 105, 102056 .

AMA Style

Peter H. Sylvers, Christopher J. Gobler. Mitigation of harmful algal blooms caused by Alexandrium catenella and reduction in saxitoxin accumulation in bivalves using cultivable seaweeds. Harmful Algae. 2021; 105 ():102056.

Chicago/Turabian Style

Peter H. Sylvers; Christopher J. Gobler. 2021. "Mitigation of harmful algal blooms caused by Alexandrium catenella and reduction in saxitoxin accumulation in bivalves using cultivable seaweeds." Harmful Algae 105, no. : 102056.

Journal article
Published: 27 April 2021 in Harmful Algae
Reads 0
Downloads 0

Dinophysis spp. are mixotrophs that are dependent on specific prey, but are also potentially reliant on dissolved nutrients. The extent to which Dinophysis relies on exogenous N and the specific biochemical pathways important for supporting its autotrophic and heterotrophic growth are unknown. Here, the nutritional ecology of Dinophysis was explored using two approaches: 1) 15N tracer experiments were conducted to quantify the concentration-dependent uptake rates and associated kinetics of various N compounds (nitrate, ammonium, urea) of Dinophysis cultures and 2) the transcriptomic responses of Dinophysis cultures grown with multiple combinations of prey and nutrients were assessed via dinoflagellate spliced leader-based transcriptome profiling. Of the N compounds examined, ammonium had the highest Vmax and affinity coefficient, and lowest Ks for both pre-starved and pre-fed cultures, collectively demonstrating the preference of Dinophysis for this N source while little-to-no nitrate uptake was observed. During the transcriptome experiments, Dinophysis grown with nitrate and without prey had the largest number of genes with lower transcript abundances, did not increase abundance of transcripts associated with nitrate/nitrite uptake or reduction, and displayed no cellular growth, suggesting D. acuminata is not capable of growing on nitrate. When offered prey, the transcriptomic response of Dinophysis included the production of phagolysosomes, enzymes involved in protein and lipid catabolism, and N acquisition through amino acid degradation pathways. Compared with cultures only offered ammonium or prey, cultures offered both ammonium and prey had the largest number of genes with increased transcript abundances, the highest growth rate, and the unique activation of multiple pathways involved in cellular catabolism, further evidencing the ability of Dinophysis to grow optimally as a mixotroph. Collectively, this study evidences the key role ammonium plays in the mixotrophic growth of Dinophysis and reveals the precise biochemical pathways that facilitate its mixotrophic growth.

ACS Style

Theresa K. Hattenrath-Lehmann; Deepak Nanjappa; Huan Zhang; Liying Yu; Jennifer A. Goleski; Senjie Lin; Christopher J. Gobler. Transcriptomic and isotopic data reveal central role of ammonium in facilitating the growth of the mixotrophic dinoflagellate, Dinophysis acuminata. Harmful Algae 2021, 104, 102031 .

AMA Style

Theresa K. Hattenrath-Lehmann, Deepak Nanjappa, Huan Zhang, Liying Yu, Jennifer A. Goleski, Senjie Lin, Christopher J. Gobler. Transcriptomic and isotopic data reveal central role of ammonium in facilitating the growth of the mixotrophic dinoflagellate, Dinophysis acuminata. Harmful Algae. 2021; 104 ():102031.

Chicago/Turabian Style

Theresa K. Hattenrath-Lehmann; Deepak Nanjappa; Huan Zhang; Liying Yu; Jennifer A. Goleski; Senjie Lin; Christopher J. Gobler. 2021. "Transcriptomic and isotopic data reveal central role of ammonium in facilitating the growth of the mixotrophic dinoflagellate, Dinophysis acuminata." Harmful Algae 104, no. : 102031.

Journal article
Published: 15 April 2021 in Marine Ecology Progress Series
Reads 0
Downloads 0

The laminarialean kelp Saccharina latissima is a common macroalga along rocky shorelines that is also frequently used in aquaculture. This study examined how ocean acidification may alter the growth of S. latissima as well as grazing on S. latissima by the gastropod Lacuna vincta. Under elevated nutrients, S. latissima experienced significantly enhanced growth at pCO2 levels ≥1200 µatm compared to ambient pCO2 (~400 µatm). Elevated pCO2 (≥830 µatm) also significantly reduced herbivory of L. vincta grazing on S. latissima relative to ambient pCO2. There was no difference in grazing of S. latissima previously grown under elevated or ambient pCO2, suggesting lowered herbivory was due to harm to the gastropods rather than alteration of the biochemical composition of the kelp. Decreased herbivory was specifically elicited when L. vincta were exposed to elevated pCO2 in the absence of food for ≥18 h prior to grazing, with reduced grazing persisting 72 h. Elevated growth of S. latissima and reduced grazing by L. vincta at 1200 µatm pCO2 combined to increase net growth rates of S. latissima more than 4-fold relative to ambient pCO2. L. vincta consumed 70% of daily production by S. latissima under ambient pCO2 but only 38 and 9% at 800 and 1200 µatm, respectively. Collectively, decreased grazing by L. vincta coupled with enhanced growth of S. latissima under elevated pCO2 demonstrates that increased CO2 associated with climate change and/or coastal processes will dually benefit commercially and ecologically important kelps by both promoting growth and reducing grazing pressure.

ACS Style

Cs Young; Mh Doall; Cj Gobler. Dual benefit of ocean acidification for the laminarialean kelp Saccharina latissima: enhanced growth and reduced herbivory. Marine Ecology Progress Series 2021, 664, 87 -102.

AMA Style

Cs Young, Mh Doall, Cj Gobler. Dual benefit of ocean acidification for the laminarialean kelp Saccharina latissima: enhanced growth and reduced herbivory. Marine Ecology Progress Series. 2021; 664 ():87-102.

Chicago/Turabian Style

Cs Young; Mh Doall; Cj Gobler. 2021. "Dual benefit of ocean acidification for the laminarialean kelp Saccharina latissima: enhanced growth and reduced herbivory." Marine Ecology Progress Series 664, no. : 87-102.

Original research article
Published: 17 March 2021 in Frontiers in Marine Science
Reads 0
Downloads 0

Pelagophytes are abundant picophytoplankton within open ocean ecosystems and the causative algae of harmful brown tide blooms in estuaries. The physiological capabilities facilitating the ecological success of pelagophytes in these diverse ecosystems remains poorly understood. Here, we investigated the transcriptional response of two coastal pelagophytes (Aureococcus anophagefferens and Aureoumbra lagunensis) and two open ocean pelagophytes (Pelagococcus subviridis and Pelagomonas calceolata) to conditions commonly found within the marine ecosystems where they thrive: low concentrations of nitrogen (N), phosphorus (P), or light. OrthoMCL was used to generate a total of 62,653 orthologous groups (OGs) with only a small fraction of these OGs (2,776 or 4.4%) being shared among all four pelagophytes. Of the commonly shared OGs, 8% were significantly differentially abundant under low N, P, or light with the majority associated with energy and lipid metabolism. Distinct responses among pelagophytes included increased abundance of transcripts encoding phosphate transporters (Aureococcus) and transcripts encoding a pyrophosphatase (Aureococcus and Pelagomonas) under low P, the expression of a suite of organic nitrogen-degrading enzymes under low N (Aureoumbra and Pelagomonas), increased abundance of transcripts encoding flavodoxins relative to ferredoxins (Pelagomonas) and transcripts encoding lysophospholipase (Pelagococcus) under low light, and both increases and decreases in abundance of transcripts encoding selenoproteins in all pelagophytes except Pelagococcus. Collectively, this study provides new information on the expressed gene compliment of these poorly characterized taxa and demonstrates that these pelagophytes possess a combination of shared and unique physiological features that likely facilitate their adaptation to distinct environmental conditions.

ACS Style

Yoonja Kang; Matthew J. Harke; Dianna L. Berry; Jackie L. Collier; Steven W. Wilhelm; Sonya T. Dyhrman; Christopher J. Gobler. Transcriptomic Responses of Four Pelagophytes to Nutrient (N, P) and Light Stress. Frontiers in Marine Science 2021, 8, 1 .

AMA Style

Yoonja Kang, Matthew J. Harke, Dianna L. Berry, Jackie L. Collier, Steven W. Wilhelm, Sonya T. Dyhrman, Christopher J. Gobler. Transcriptomic Responses of Four Pelagophytes to Nutrient (N, P) and Light Stress. Frontiers in Marine Science. 2021; 8 ():1.

Chicago/Turabian Style

Yoonja Kang; Matthew J. Harke; Dianna L. Berry; Jackie L. Collier; Steven W. Wilhelm; Sonya T. Dyhrman; Christopher J. Gobler. 2021. "Transcriptomic Responses of Four Pelagophytes to Nutrient (N, P) and Light Stress." Frontiers in Marine Science 8, no. : 1.

Journal article
Published: 30 January 2021 in Ecological Engineering
Reads 0
Downloads 0

Three distinct septic systems designed for onsite removal of nitrogen (N) from residential wastewater were installed at the Massachusetts Alternative Septic System Test Center (MASSTC) and at homes across Suffolk County (SC), New York. All configurations featured nitrifying sand beds coupled with denitrifying biofilters composed of 1) a lined, saturated sand and woodchip layer, 2) a saturated box filled with woodchips, or 3) an unlined, unsaturated sand and woodchip layer. Total N (TN) in final effluent discharge from the three systems at MASSTC over more than two years were 7.1 ± 7.8, 4.3 ± 4.2, and 6.9 ± 8.4 mg N L−1, respectively representing TN reductions of 83%, 87%, and 84% from influent TN. Systems at MASSTC also removed on average 90.0–99.9% of 10 of 11 organic contaminants in pharmaceutical and personal care products, microbes indicative of pathogens, and biochemical oxygen demand. Over periods up to 16 months from start-up, effluent from three lined, one woodchip box, and three unlined systems in SC averaged 8.3 ± 9.2, 5.3 ± 3.7, and 8.7 ± 4.9 mg-TN L−1 representing removal rates of 90%, 94%, and 88%, respectively. For all systems, wastewater N was effectively nitrified year-round; N removal varied seasonally as denitrification attenuated in winter. Substantial quantities of TN were removed in the sand beds, likely due to denitrification in anoxic micro-zones. While elevated levels of carbon leached from the wood-based biofilters installed at MASSTC during the first 60 days of operation, no substantial decline in dissolved organic carbon or N removal was observed between the first 15 months of operation and the following 12 months. Collectively, the performance of these non-proprietary, passive systems suggest they may be a useful alternative septic system for protection of groundwater from elevated levels of N, organic contaminants, and pathogens.

ACS Style

Christopher J. Gobler; Stuart Waugh; Caitlin Asato; Patricia M. Clyde; Samantha C. Nyer; Molly Graffam; Bruce Brownawell; Arjun K. Venkatesan; Jennifer A. Goleski; Roy E. Price; Xinwei Mao; Frank M. Russo; George Heufelder; Harold W. Walker. Removing 80%–90% of nitrogen and organic contaminants with three distinct passive, lignocellulose-based on-site septic systems receiving municipal and residential wastewater. Ecological Engineering 2021, 161, 106157 .

AMA Style

Christopher J. Gobler, Stuart Waugh, Caitlin Asato, Patricia M. Clyde, Samantha C. Nyer, Molly Graffam, Bruce Brownawell, Arjun K. Venkatesan, Jennifer A. Goleski, Roy E. Price, Xinwei Mao, Frank M. Russo, George Heufelder, Harold W. Walker. Removing 80%–90% of nitrogen and organic contaminants with three distinct passive, lignocellulose-based on-site septic systems receiving municipal and residential wastewater. Ecological Engineering. 2021; 161 ():106157.

Chicago/Turabian Style

Christopher J. Gobler; Stuart Waugh; Caitlin Asato; Patricia M. Clyde; Samantha C. Nyer; Molly Graffam; Bruce Brownawell; Arjun K. Venkatesan; Jennifer A. Goleski; Roy E. Price; Xinwei Mao; Frank M. Russo; George Heufelder; Harold W. Walker. 2021. "Removing 80%–90% of nitrogen and organic contaminants with three distinct passive, lignocellulose-based on-site septic systems receiving municipal and residential wastewater." Ecological Engineering 161, no. : 106157.

Original paper
Published: 29 January 2021 in Biological Invasions
Reads 0
Downloads 0

Coastal ecosystems are prone to multiple anthropogenic and natural stressors including eutrophication, acidification, and invasive species. While the growth of some macroalgae can be promoted by excessive nutrient loading and/or elevated pCO2, responses differ among species and ecosystems. Native to the western Pacific Ocean, the filamentous, turf-forming rhodophyte, Dasysiphonia japonica, appeared in estuaries of the northeastern Atlantic Ocean during the 1980s and the northwestern Atlantic Ocean during the late 2000s. Here, we report on the southernmost expansion of the D. japonica in North America and the effects of elevated nutrients and elevated pCO2 on the growth of D. japonica over an annual cycle in Long Island, New York, USA. Growth limitation of the macroalga varied seasonally. During winter and spring, when water temperatures were < 15 °C, growth was significantly enhanced by elevated pCO2 (p < 0.05). During summer and fall, when the water temperature was 15–24 °C, growth was significantly higher under elevated nutrient treatments (p < 0.05). When temperatures reached 28 °C, the macroalga grew poorly and was unaffected by nutrients or pCO2. The δ13C content of regional populations of D. japonica was −30‰, indicating the macroalga is an obligate CO2-user. This result, coupled with significantly increased growth under elevated pCO2 when temperatures were < 15 °C, indicates this macroalga is carbon-limited during colder months, when in situ pCO2 was significantly lower in Long Island estuaries compared to warmer months when estuaries are enriched in metabolically derived CO2. The δ15N content of this macroalga (9‰) indicated it utilized wastewater-derived N and its N limitation during warmer months coincided with lower concentrations of dissolved inorganic N in the water column. Given the stimulatory effect of nutrients on this macroalga and that eutrophication can promote seasonally elevated pCO2, this study suggests that eutrophic estuaries subject to peak annual temperatures < 28 °C may be particularly vulnerable to future invasions of D. japonica as ocean acidification intensifies. Conversely, nutrient reductions would serve as a management approach that would make coastal regions more resilient to invasions by this macroalga.

ACS Style

Craig S. Young; Christopher J. Gobler. Coastal ocean acidification and nitrogen loading facilitate invasions of the non-indigenous red macroalga, Dasysiphonia japonica. Biological Invasions 2021, 23, 1367 -1391.

AMA Style

Craig S. Young, Christopher J. Gobler. Coastal ocean acidification and nitrogen loading facilitate invasions of the non-indigenous red macroalga, Dasysiphonia japonica. Biological Invasions. 2021; 23 (5):1367-1391.

Chicago/Turabian Style

Craig S. Young; Christopher J. Gobler. 2021. "Coastal ocean acidification and nitrogen loading facilitate invasions of the non-indigenous red macroalga, Dasysiphonia japonica." Biological Invasions 23, no. 5: 1367-1391.

Journal article
Published: 16 December 2020 in Journal of Marine Science and Engineering
Reads 0
Downloads 0

Life history (life cycle) plays a vital role in the ecology of some microalgae; however, the well-known brown-tide-causing pelagophyte Aureococcus anophagefferens has been barely investigated in this regard. Recently, based mainly on detections in marine sediments from China, we proved that this organism has a resting stage. We, therefore, conducted a follow-up study to characterize the resting stage cells (RSCs) of A. anophagefferens using the culture CCMP1984 (Culture Collection of Marine Phytoplankton). The RSCs were spherical, larger than the vegetative cells, and smooth in cell surface and contained more aggregated plastid but more vacuolar space than vegetative cells. RSCs contained a conspicuous lipid-enriched red droplet. We found a 9.9-fold decrease in adenosine triphosphate (ATP) content from vegetative cells to RSCs, indicative of a "resting" or dormant physiological state. The RSCs stored for 3 months (at 4 °C in darkness) readily reverted back to vegetative growth within 20 days after being transferred to the conditions for routine culture maintenance. Our results indicate that the RSCs of A. anophagefferens are a dormant state that differs from vegetative cells morphologically and physiologically, and that RSCs likely enable the species to survive unfavorable conditions, seed annual blooms, and facilitate its cosmopolitan distribution that we recently documented.

ACS Style

Zhaopeng Ma; Zhangxi Hu; Yunyan Deng; Lixia Shang; Christophere J. Gobler; Ying Zhong Tang. Laboratory Culture-Based Characterization of the Resting Stage Cells of the Brown-Tide-Causing Pelagophyte, Aureococcus anophagefferens. Journal of Marine Science and Engineering 2020, 8, 1027 .

AMA Style

Zhaopeng Ma, Zhangxi Hu, Yunyan Deng, Lixia Shang, Christophere J. Gobler, Ying Zhong Tang. Laboratory Culture-Based Characterization of the Resting Stage Cells of the Brown-Tide-Causing Pelagophyte, Aureococcus anophagefferens. Journal of Marine Science and Engineering. 2020; 8 (12):1027.

Chicago/Turabian Style

Zhaopeng Ma; Zhangxi Hu; Yunyan Deng; Lixia Shang; Christophere J. Gobler; Ying Zhong Tang. 2020. "Laboratory Culture-Based Characterization of the Resting Stage Cells of the Brown-Tide-Causing Pelagophyte, Aureococcus anophagefferens." Journal of Marine Science and Engineering 8, no. 12: 1027.

Original research article
Published: 17 September 2020 in Frontiers in Marine Science
Reads 0
Downloads 0

Acidification and deoxygenation are two consequences of climate change that also co-occur in eutrophied coastal zones and can have deleterious effects on marine life. While the effects of hypoxia on marine herbivores have been well-studied, how ocean acidification combined with hypoxia affects herbivory is poorly understood. This study examined how herbivory and survival by the gastropod Lacuna vincta grazing on the macroalgae Ulva rigida was influenced by hypoxia and ocean acidification, alone and in combination, with and without food limitation. Experiments exposed L. vincta to a range of environmentally realistic dissolved oxygen (0.7 – 8 mg L–1) and pH (7.3 – 8.0 total scale) conditions for 3 – 72 h, with and without a starvation period and quantified herbivory and survival. While acidified conditions (pH < 7.4) reduced herbivory when combined with food limitation, low oxygen conditions (< 4 mg L–1) reduced herbivory and survival regardless of food supply. When L. vincta were starved and grazed in acidified conditions herbivory was additively reduced, whereas starvation and hypoxia synergistically reduced grazing rates. Overall, low oxygen had a more inhibitory effect on herbivory than low pH. Shorter exposure times (9, 6, and 3 h) were required to reduce grazing at lower DO levels (∼2.4, ∼1.6, and ∼0.7 mg L–1, respectively). Herbivory ceased entirely following a three-hour exposure to DO of 0.7 mg L–1 suggesting that episodes of diurnal hypoxia disrupt grazing by these gastropods. The suppression of herbivory in response to acidified and hypoxic conditions could create a positive feedback loop that promotes ‘green tides’ whereby reduced grazing facilitates the overgrowth of macroalgae that cause nocturnal acidification and hypoxia, further disrupting herbivory and promoting the growth of macroalgae. Such feedback loops could have broad implications for estuarine ecosystems where L. vincta is a dominant macroalgal grazer and will intensify as climate change accelerates.

ACS Style

Craig S. Young; Christopher J. Gobler. Hypoxia and Acidification, Individually and in Combination, Disrupt Herbivory and Reduce Survivorship of the Gastropod, Lacuna vincta. Frontiers in Marine Science 2020, 7, 1 .

AMA Style

Craig S. Young, Christopher J. Gobler. Hypoxia and Acidification, Individually and in Combination, Disrupt Herbivory and Reduce Survivorship of the Gastropod, Lacuna vincta. Frontiers in Marine Science. 2020; 7 ():1.

Chicago/Turabian Style

Craig S. Young; Christopher J. Gobler. 2020. "Hypoxia and Acidification, Individually and in Combination, Disrupt Herbivory and Reduce Survivorship of the Gastropod, Lacuna vincta." Frontiers in Marine Science 7, no. : 1.

Journal article
Published: 29 June 2020 in Toxins
Reads 0
Downloads 0

Hydrogen peroxide (H2O2) has been proposed as an agent to mitigate toxic cyanobacterial blooms due to the heightened sensitivity of cyanobacteria to reactive oxygen species relative to eukaryotic organisms. Here, experiments were conducted using water from four diverse, eutrophic lake ecosystems to study the effects of H2O2 on cyanobacteria and non-target members of the microbial community. H2O2 was administered at 4 µg L−1 and a combination of fluorometry, microscopy, flow cytometry, and high throughput DNA sequencing were used to quantify the effects on eukaryotic and prokaryotic plankton communities. The addition of H2O2 resulted in a significant reduction in cyanobacteria levels in nearly all experiments (10 of 11), reducing their relative abundance from, on average, 85% to 29% of the total phytoplankton community with Planktothrix being highly sensitive, Microcystis being moderately sensitive, and Cylindrospermopsis being most resistant. Concurrently, eukaryotic algal levels increased in 75% of experiments. The bacterial phyla Actinobacteria, cyanobacteria, Planctomycetes, and Verrucomicrobia were most negatively impacted by H2O2, with Actinobacteria being the most sensitive. The ability of H2O2 to reduce, but not fully eliminate, cyanobacteria from the eutrophic water bodies studied here suggests it may not be an ideal mitigation approach in high biomass ecosystems.

ACS Style

Mark W. Lusty; Christopher J. Gobler. The Efficacy of Hydrogen Peroxide in Mitigating Cyanobacterial Blooms and Altering Microbial Communities across Four Lakes in NY, USA. Toxins 2020, 12, 428 .

AMA Style

Mark W. Lusty, Christopher J. Gobler. The Efficacy of Hydrogen Peroxide in Mitigating Cyanobacterial Blooms and Altering Microbial Communities across Four Lakes in NY, USA. Toxins. 2020; 12 (7):428.

Chicago/Turabian Style

Mark W. Lusty; Christopher J. Gobler. 2020. "The Efficacy of Hydrogen Peroxide in Mitigating Cyanobacterial Blooms and Altering Microbial Communities across Four Lakes in NY, USA." Toxins 12, no. 7: 428.

Original research article
Published: 28 May 2020 in Frontiers in Microbiology
Reads 0
Downloads 0

The toxic cyanobacterium Microcystis is one of the most pervasive harmful algal bloom (HAB) genera and naturally occurs in large colonies known to harbor diverse heterotrophic bacterial assemblages. While colony-associated microbiomes may influence Microcystis blooms, there remains a limited understanding of the structure and functional potential of these communities and how they may be shaped by changing environmental conditions. To address this gap, we compared the dynamics of Microcystis-attached (MCA), free-living (FL), and whole water (W) microbiomes during Microcystis blooms using next-generation amplicon sequencing (16S rRNA), a predictive metagenome software, and other bioinformatic approaches. Microbiomes were monitored through high resolution spatial-temporal surveys across two North American lakes, Lake Erie (LE) and Lake Agawam (LA; Long Island, NY, United States) in 2017, providing the largest dataset of these fractions to date. Sequencing of 126 samples generated 7,922,628 sequences that clustered into 7,447 amplicon sequence variants (ASVs) with 100% sequence identity. Across lakes, the MCA microbiomes were significantly different than the FL and W fractions being significantly enriched in Gemmatimonadetes, Burkholderiaceae, Rhizobiales, and Cytophagales and depleted of Actinobacteria. Further, although MCA communities harbored > 900 unique ASVs, they were significantly less diverse than the other fractions with diversity inversely related to bloom intensity, suggesting increased selection pressure on microbial communities as blooms intensified. Despite taxonomic differences between lakes, predicted metagenomes revealed conserved functional potential among MCA microbiomes. MCA communities were significantly enriched in pathways involved in N and P cycling and microcystin-degradation. Taxa potentially capable of N2-fixation were significantly enriched (p < 0.05) and up to four-fold more abundant within the MCA faction relative to other fractions, potentially aiding in the proliferation of Microcystis blooms during low N conditions. The MCA predicted metagenomes were conserved over 8 months of seasonal changes in temperature and N availability despite strong temporal succession in microbiome composition. Collectively, these findings indicate that Microcystis colonies harbor a statistically distinct microbiome with a conserved functional potential that may help facilitate bloom persistence under environmentally unfavorable conditions.

ACS Style

Jennifer G. Jankowiak; Christopher J. Gobler. The Composition and Function of Microbiomes Within Microcystis Colonies Are Significantly Different Than Native Bacterial Assemblages in Two North American Lakes. Frontiers in Microbiology 2020, 11, 1016 .

AMA Style

Jennifer G. Jankowiak, Christopher J. Gobler. The Composition and Function of Microbiomes Within Microcystis Colonies Are Significantly Different Than Native Bacterial Assemblages in Two North American Lakes. Frontiers in Microbiology. 2020; 11 ():1016.

Chicago/Turabian Style

Jennifer G. Jankowiak; Christopher J. Gobler. 2020. "The Composition and Function of Microbiomes Within Microcystis Colonies Are Significantly Different Than Native Bacterial Assemblages in Two North American Lakes." Frontiers in Microbiology 11, no. : 1016.

Journal article
Published: 24 April 2020
Reads 0
Downloads 0
ACS Style

Stephen J Tomasetti; Christopher J Gobler. Dissolved oxygen and pH criteria leave fisheries at risk. 2020, 368, 372 -373.

AMA Style

Stephen J Tomasetti, Christopher J Gobler. Dissolved oxygen and pH criteria leave fisheries at risk. . 2020; 368 (6489):372-373.

Chicago/Turabian Style

Stephen J Tomasetti; Christopher J Gobler. 2020. "Dissolved oxygen and pH criteria leave fisheries at risk." 368, no. 6489: 372-373.

Journal article
Published: 25 January 2020 in Water Research
Reads 0
Downloads 0

In this study, a semi-batch, bench-scale UV/hydrogen peroxide (UV/H2O2) advanced oxidation process system was used to investigate how typical groundwater quality parameters (pH, alkalinity, natural organic matter (NOM), nitrate, and iron) influence the treatment of 1,4-dioxane. Deionized (DI) water spiked with 1,4-dioxane (100 μg L−1), treated using H2O2 (10 mg L−1) in a commercially available UV system (40 W low-pressure lamp) showed an UV fluence-based first-order rate constant (k’) and electrical energy-per-order (EEO) of 4.32✕10−3 cm2-mJ−1 and 0.15 kWh-m−3-order−1, respectively. The most abundant byproduct generated in spiked-DI water was oxalic acid (up to 55 μg L−1), followed by formic and acetic acids. The k’ showed no significant difference at pH ranging from 5 to 7 and at low alkalinity concentrations ( 0.05) in predicting k’ for the removal of 1,4-dioxane from groundwater. This study provides the first systematic evaluation of the impacts of groundwater quality on UV/H2O2 process to remove environmentally relevant levels of 1,4-dioxane and reports standardized performance-related parameters to aid in the design and evaluation of full-scale systems.

ACS Style

Cheng-Shiuan Lee; Arjun K. Venkatesan; Harold W. Walker; Christopher J. Gobler. Impact of groundwater quality and associated byproduct formation during UV/hydrogen peroxide treatment of 1,4-dioxane. Water Research 2020, 173, 115534 .

AMA Style

Cheng-Shiuan Lee, Arjun K. Venkatesan, Harold W. Walker, Christopher J. Gobler. Impact of groundwater quality and associated byproduct formation during UV/hydrogen peroxide treatment of 1,4-dioxane. Water Research. 2020; 173 ():115534.

Chicago/Turabian Style

Cheng-Shiuan Lee; Arjun K. Venkatesan; Harold W. Walker; Christopher J. Gobler. 2020. "Impact of groundwater quality and associated byproduct formation during UV/hydrogen peroxide treatment of 1,4-dioxane." Water Research 173, no. : 115534.

Journal article
Published: 08 January 2020 in Diversity
Reads 0
Downloads 0

Estuaries serve as important nursery habitats for various species of early-life stage fish, but can experience cooccurring acidification and hypoxia that can vary diurnally in intensity. This study examines the effects of acidification (pH 7.2–7.4) and hypoxia (dissolved oxygen (DO) ~ 2–4 mg L−1) as individual and combined stressors on four fitness metrics for three species of forage fish endemic to the U.S. East Coast: Menidia menidia, Menidia beryllina, and Cyprinodon variegatus. Additionally, the impacts of various durations of exposure to these two stressors was also assessed to explore the sensitivity threshold for larval fishes under environmentally-representative conditions. C. variegatus was resistant to chronic low pH, while M. menidia and M. beryllina experienced significantly reduced survival and hatch time, respectively. Exposure to hypoxia resulted in reduced hatch success of both Menidia species, as well as diminished survival of M. beryllina larvae. Diurnal exposure to low pH and low DO for 4 or 8 h did not alter survival of M. beryllina, although 8 or 12 h of daily exposure through the 10 days posthatch significantly depressed larval size. In contrast, M. menidia experienced significant declines in survival for all intervals of diel cycling hypoxia and acidification (4–12 h). Exposure to 12-h diurnal hypoxia generally elicited negative effects equal to, or of greater severity, than chronic exposure to low DO at the same levels despite significantly higher mean DO exposure concentrations. This evidences a substantial biological cost to adapting to changing DO levels, and implicates diurnal cycling of DO as a significant threat to fish larvae in estuaries. Larval responses to hypoxia, and to a lesser extent acidification, in this study on both continuous and diurnal timescales indicate that estuarine conditions throughout the spawning and postspawn periods could adversely affect stocks of these fish, with diverse implications for the remainder of the food web.

ACS Style

Brooke K. Morrell; Christopher J. Gobler. Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes. Diversity 2020, 12, 25 .

AMA Style

Brooke K. Morrell, Christopher J. Gobler. Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes. Diversity. 2020; 12 (1):25.

Chicago/Turabian Style

Brooke K. Morrell; Christopher J. Gobler. 2020. "Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes." Diversity 12, no. 1: 25.

Journal article
Published: 07 January 2020 in Marine Environmental Research
Reads 0
Downloads 0

Ocean acidification alters seawater carbonate chemistry, which can have detrimental impacts for calcifying organisms such as bivalves. This study investigated the physiological cost of resilience to acidification in Mercenaria mercenaria, with a focus on overall immune performance following exposure to Vibrio spp. Larval and juvenile clams reared in seawater with high pCO2 (~1200 ppm) displayed an enhanced susceptibility to bacterial pathogens. Higher susceptibility to infection in clams grown under acidified conditions was derived from a lower immunity to infection more so than an increase in growth of bacteria under high pCO2. A reciprocal transplant of juvenile clams demonstrated the highest mortality amongst animals transplanted from low pCO2/high pH to high pCO2/low pH conditions and then exposed to bacterial pathogens. Collectively, these results suggest that increased pCO2 will result in immunocompromised larvae and juveniles, which could have complex and pernicious effects on hard clam populations.

ACS Style

Caroline Schwaner; Michelle Barbosa; Peter Connors; Tae-Jin Park; Darren de Silva; Andrew Griffith; Christopher J. Gobler; Emmanuelle Pales Espinosa; Bassem Allam. Experimental acidification increases susceptibility of Mercenaria mercenaria to infection by Vibrio species. Marine Environmental Research 2020, 154, 104872 .

AMA Style

Caroline Schwaner, Michelle Barbosa, Peter Connors, Tae-Jin Park, Darren de Silva, Andrew Griffith, Christopher J. Gobler, Emmanuelle Pales Espinosa, Bassem Allam. Experimental acidification increases susceptibility of Mercenaria mercenaria to infection by Vibrio species. Marine Environmental Research. 2020; 154 ():104872.

Chicago/Turabian Style

Caroline Schwaner; Michelle Barbosa; Peter Connors; Tae-Jin Park; Darren de Silva; Andrew Griffith; Christopher J. Gobler; Emmanuelle Pales Espinosa; Bassem Allam. 2020. "Experimental acidification increases susceptibility of Mercenaria mercenaria to infection by Vibrio species." Marine Environmental Research 154, no. : 104872.

Journal article
Published: 25 December 2019 in Harmful Algae
Reads 0
Downloads 0

Climate change is transforming aquatic ecosystems. Coastal waters have experienced progressive warming, acidification, and deoxygenation that will intensify this century. At the same time, there is a scientific consensus that the public health, recreation, tourism, fishery, aquaculture, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past several decades. The extent to which climate change is intensifying these HABs is not fully clear, but there has been a wealth of research on this topic this century alone. Indeed, the United Nations' Intergovernmental Panel on Climate Change's (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) approved in September 2019 was the first IPCC report to directly link HABs to climate change. In the Summary for Policy Makers, the report made the following declarations with “high confidence”: In addition, the report specifically outlines a series of linkages between heat waves and HABs. These statements about HABs and climate change and the high levels of confidence ascribed to them provides clear evidence that the field of HABs and climate change has matured and has, perhaps, reached a first plateau of certainty. While there are well-documented global trends in HABs being promoted by human activity, including climate change, individual events are driven by local, regional, and global drivers, making it critical to carefully evaluate the conditions and responses at appropriate scales. It is within this context that the first Special Issue on Climate Change and Harmful Algal Blooms is published in Harmful Algae.

ACS Style

Christopher J. Gobler. Climate Change and Harmful Algal Blooms: Insights and perspective. Harmful Algae 2019, 91, 101731 .

AMA Style

Christopher J. Gobler. Climate Change and Harmful Algal Blooms: Insights and perspective. Harmful Algae. 2019; 91 ():101731.

Chicago/Turabian Style

Christopher J. Gobler. 2019. "Climate Change and Harmful Algal Blooms: Insights and perspective." Harmful Algae 91, no. : 101731.

Research article
Published: 07 November 2019 in PLOS ONE
Reads 0
Downloads 0

While harmful algal blooms caused by the ichthyotoxic dinoflagellate, Cochlodinium (Margalefidinium) polykrikoides, are allelopathic and may have unique associations with bacteria, a comprehensive assessment of the planktonic communities associated with these blooms has been lacking. Here, we used high-throughput amplicon sequencing to assess size fractionated (0.2 and 5 μm) bacterial (16S) and phytoplankton assemblages (18S) associated with blooms of C. polykrikoides during recurrent blooms in NY, USA. Over a three-year period, samples were collected inside ('patch') and outside ('non-patch') dense accumulations of C. polykrikoides to assess the microbiome associated with these blooms. Eukaryotic plankton communities of blooms had significantly lower diversity than non-bloom samples, and non-bloom samples hosted 30 eukaryotic operational taxonomic units (OTUs) not found within blooms, suggesting they may have been allelopathically excluded from blooms. Differential abundance analyses revealed that C. polykrikoides blooms were significantly enriched in dinoflagellates (p0.2μm fraction of blooms was dominated by an uncultured bacterium from the SAR11 clade, while the >5μm size fraction was co-dominated by an uncultured bacterium from Rhodobacteraceae and Coraliomargarita. Two bacterial lineages within the >0.2μm fraction, as well as the Gammaproteobacterium, Halioglobus, from the >5μm fraction were unique to the microbiome of blooms, while there were 154 bacterial OTUs only found in non-bloom waters. Collectively, these findings reveal the unique composition and potential function of eukaryotic and prokaryotic communities associated with C. polykrikoides blooms.

ACS Style

Theresa K. Hattenrath-Lehmann; Jennifer Jankowiak; Florian Koch; Christopher J. Gobler. Prokaryotic and eukaryotic microbiomes associated with blooms of the ichthyotoxic dinoflagellate Cochlodinium (Margalefidinium) polykrikoides in New York, USA, estuaries. PLOS ONE 2019, 14, e0223067 .

AMA Style

Theresa K. Hattenrath-Lehmann, Jennifer Jankowiak, Florian Koch, Christopher J. Gobler. Prokaryotic and eukaryotic microbiomes associated with blooms of the ichthyotoxic dinoflagellate Cochlodinium (Margalefidinium) polykrikoides in New York, USA, estuaries. PLOS ONE. 2019; 14 (11):e0223067.

Chicago/Turabian Style

Theresa K. Hattenrath-Lehmann; Jennifer Jankowiak; Florian Koch; Christopher J. Gobler. 2019. "Prokaryotic and eukaryotic microbiomes associated with blooms of the ichthyotoxic dinoflagellate Cochlodinium (Margalefidinium) polykrikoides in New York, USA, estuaries." PLOS ONE 14, no. 11: e0223067.

Conference paper
Published: 05 June 2019 in Proceedings of the Royal Society of London. Series B: Biological Sciences
Reads 0
Downloads 0

Since the early 1990s, ocean temperatures have increased and blooms of the icthyotoxic dinoflagellate Cochlodinium polykrikoides (a.k.a. Margalefidinium polykrikoides ) have become more widespread across the Northern Hemisphere. This study used high-resolution (1–30 km), satellite-based sea surface temperature records since 1982 to model trends in growth and bloom season length for strains of C. polykrikoides inhabiting North American and East Asian coastlines to understand how warming has altered blooms in these regions. Methods provided approximately 180× greater spatial resolution than previous studies of the impacts of warming on harmful algae, providing novel insight into near shore, coastal environments. Along the US East Coast, significant increases in potential growth rates and bloom season length for North American ribotypes were observed with bloom-favourable conditions becoming established earlier and persisting longer from Chesapeake Bay through Cape Cod, areas where blooms have become newly established and/or intensified this century. Within the Sea of Japan, modelled mean potential growth rates and bloom season length of East Asian ribotypes displayed a significant positive correlation with rising sea surface temperatures since 1982, a period during which observed maximal cell densities of C. polykrikoides blooms have significantly increased. Results suggest that warming has contributed, in part, to altering the phenology of C. polykrikoides populations, potentially expanding its realized niche in temperate zones of the Northern Hemisphere.

ACS Style

Andrew W. Griffith; Owen M. Doherty; Christopher J. Gobler. Ocean warming along temperate western boundaries of the Northern Hemisphere promotes an expansion of Cochlodinium polykrikoides blooms. Proceedings of the Royal Society of London. Series B: Biological Sciences 2019, 286, 20190340 .

AMA Style

Andrew W. Griffith, Owen M. Doherty, Christopher J. Gobler. Ocean warming along temperate western boundaries of the Northern Hemisphere promotes an expansion of Cochlodinium polykrikoides blooms. Proceedings of the Royal Society of London. Series B: Biological Sciences. 2019; 286 (1904):20190340.

Chicago/Turabian Style

Andrew W. Griffith; Owen M. Doherty; Christopher J. Gobler. 2019. "Ocean warming along temperate western boundaries of the Northern Hemisphere promotes an expansion of Cochlodinium polykrikoides blooms." Proceedings of the Royal Society of London. Series B: Biological Sciences 286, no. 1904: 20190340.

Review article
Published: 21 May 2019 in Harmful Algae
Reads 0
Downloads 0

Marine and freshwater ecosystems are warming, acidifying, and deoxygenating as a consequence of climate change. In parallel, the impacts of harmful algal blooms (HABs) on these ecosystems are intensifying. Many eutrophic habitats that host recurring HABs already experience thermal extremes, low dissolved oxygen, and low pH, making these locations potential sentinel sites for conditions that will become more common in larger-scale systems as climate change accelerates. While studies of the effects of HABs or individual climate change stressors on aquatic organisms have been relatively common, studies assessing their combined impacts have been rare. Those doing so have reported strong species- and strain-specific interactions between HAB species and climate change co-stressors yielding outcomes for aquatic organisms that could not have been predicted based on investigations of these factors individually. This review provides an ecological and physiological framework for considering HABs as a climate change co-stressor and considers the consequences of their combined occurrence for coastal ecosystems. This review also highlights critical gaps in our understanding of HABs as a climate change co-stressor that must be addressed in order to develop management plans that adequately protect fisheries, aquaculture, aquatic ecosystems, and human health. Ultimately, incorporating HAB species into experiments and monitoring programs where the effects of multiple climate change stressors are considered will provide a more ecologically relevant perspective of the structure and function of marine ecosystems in future, climate-altered systems.

ACS Style

Andrew W. Griffith; Christopher J. Gobler. Harmful algal blooms: A climate change co-stressor in marine and freshwater ecosystems. Harmful Algae 2019, 91, 101590 .

AMA Style

Andrew W. Griffith, Christopher J. Gobler. Harmful algal blooms: A climate change co-stressor in marine and freshwater ecosystems. Harmful Algae. 2019; 91 ():101590.

Chicago/Turabian Style

Andrew W. Griffith; Christopher J. Gobler. 2019. "Harmful algal blooms: A climate change co-stressor in marine and freshwater ecosystems." Harmful Algae 91, no. : 101590.

Journal article
Published: 30 April 2019 in Marine Environmental Research
Reads 0
Downloads 0

The effects of co-occurring harmful algal blooms (HABs) on marine organisms is largely unknown. We assessed the individual and combined impacts of the toxin producing HABs, Alexandrium catenella and Dinophysis acuminata, and a non-toxin-producing HAB (Gymnodinium instriatum) on early life stages of two estuarine fish species (Menidia beryllina and Cyprinodon variegatus). Lethal (i.e. time to death) and sublethal (i.e. growth, grazing rate, and swimming activity) effects of cultured HABs were investigated for eleutheroembryo and larval life stages. Mixed algal treatments (i.e. A. catenella and D. acuminata mixtures) were often equally toxic as A. catenella monoculture treatments alone, although responses depended on the fish species and life stage. Fish exposed to toxin producing HABs died significantly sooner (i.e. <1–3 days) than controls. Significant differences in sublethal effects were also found between fed controls and toxic HAB treatments, although responses were often similar to G. instriatum or starved controls.

ACS Style

Konstantine J. Rountos; Jennifer J. Kim; Theresa K. Hattenrath-Lehmann; Christopher J. Gobler. Effects of the harmful algae, Alexandrium catenella and Dinophysis acuminata, on the survival, growth, and swimming activity of early life stages of forage fish. Marine Environmental Research 2019, 148, 46 -56.

AMA Style

Konstantine J. Rountos, Jennifer J. Kim, Theresa K. Hattenrath-Lehmann, Christopher J. Gobler. Effects of the harmful algae, Alexandrium catenella and Dinophysis acuminata, on the survival, growth, and swimming activity of early life stages of forage fish. Marine Environmental Research. 2019; 148 ():46-56.

Chicago/Turabian Style

Konstantine J. Rountos; Jennifer J. Kim; Theresa K. Hattenrath-Lehmann; Christopher J. Gobler. 2019. "Effects of the harmful algae, Alexandrium catenella and Dinophysis acuminata, on the survival, growth, and swimming activity of early life stages of forage fish." Marine Environmental Research 148, no. : 46-56.

Original research
Published: 27 March 2019 in Ecology and Evolution
Reads 0
Downloads 0

Global ocean change threatens marine life, yet a mechanistic understanding of how organisms are affected by specific stressors is poorly understood. Here, we identify and compare the unique and common transcriptomic responses of an organism experiencing widespread fisheries declines, Argopecten irradians (bay scallop) exposed to multiple stressors including high pCO2, elevated temperature, and two species of harmful algae, Cochlodinium (aka Margalefidinium) polykrikoides and Aureococcus anophagefferens using high-throughput sequencing (RNA-seq). After 48 hr of exposure, scallop transcriptomes revealed distinct expression profiles with larvae exposed to harmful algae (C. polykrikoides and A. anophagefferens) displaying broader responses in terms of significantly and differentially expressed (DE) transcripts (44,922 and 4,973; respectively) than larvae exposed to low pH or elevated temperature (559 and 467; respectively). Patterns of expression between larvae exposed to each harmful algal treatment were, however, strikingly different with larvae exposed to A. anophagefferens displaying large, significant declines in the expression of transcripts (n = 3,615; 87% of DE transcripts) whereas exposure to C. polykrikoides increased the abundance of transcripts, more than all other treatments combined (n = 43,668; 97% of DE transcripts). Larvae exposed to each stressor up-regulated a common set of 21 genes associated with protein synthesis, cellular metabolism, shell growth, and membrane transport. Larvae exposed to C. polykrikoides displayed large increases in antioxidant-associated transcripts, whereas acidification-exposed larvae increased abundance of transcripts associated with shell formation. After 10 days of exposure, each harmful algae caused declines in survival that were significantly greater than all other treatments. Collectively, this study reveals the common and unique transcriptional responses of bivalve larvae to stressors that promote population declines within coastal zones, providing insight into the means by which they promote mortality as well as traits possessed by bay scallops that enable potential resistance.

ACS Style

Andrew W. Griffith; Matthew J. Harke; Elizabeth DePasquale; Dianna L. Berry; Christopher J. Gobler. The harmful algae,Cochlodinium polykrikoidesandAureococcus anophagefferens, elicit stronger transcriptomic and mortality response in larval bivalves (Argopecten irradians) than climate change stressors. Ecology and Evolution 2019, 9, 4931 -4948.

AMA Style

Andrew W. Griffith, Matthew J. Harke, Elizabeth DePasquale, Dianna L. Berry, Christopher J. Gobler. The harmful algae,Cochlodinium polykrikoidesandAureococcus anophagefferens, elicit stronger transcriptomic and mortality response in larval bivalves (Argopecten irradians) than climate change stressors. Ecology and Evolution. 2019; 9 (8):4931-4948.

Chicago/Turabian Style

Andrew W. Griffith; Matthew J. Harke; Elizabeth DePasquale; Dianna L. Berry; Christopher J. Gobler. 2019. "The harmful algae,Cochlodinium polykrikoidesandAureococcus anophagefferens, elicit stronger transcriptomic and mortality response in larval bivalves (Argopecten irradians) than climate change stressors." Ecology and Evolution 9, no. 8: 4931-4948.