SEA faculty and staff are active in their fields and contribute regularly at professional conferences and to scholarly journals. We encourage SEA Semester students to stay involved in the research projects they contribute to during their time at SEA, and many have been included as authors on papers resulting from this work. See the list below for recent scholarly work by SEA staff and students. Scientific research aboard SEA vessels has contributed to over 50 publications in oceanography, environmental science, biology, geology, chemistry, physics, and other fields. Click here for a complete list of scientific publications.
#denotes SEA faculty author
^denotes SEA Semester student author
*denotes SEA Semester alumnus
Seabirds, gyres and global trends in plastic pollution
van Franeker, J. A. and K. L. Law#, 2015. Environmental Pollution 203, 89-96. doi:10.1016/j.envpol.2015.02.034
Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters.
Full Abstract: Click for Details
Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly “lost” from the ocean surface to other as-yet undetermined sinks in the marine environment.
Read the paper
Association for the Sciences of Limnology and Oceanography: Granada, Spain
Short-Term Microbial Community Assembly on Plastic Marine Debris: Evidence from Experimental Colonization Studies in the Waters of Woods Hole, MA, USA
Taylor, S.^; Cramer, K.; Dooley, K.^; Lourie, W.^; Mincer, T. J.; Amaral-Zettler, L. A.; Zettler, E. R.#
Recent studies on plastic marine debris have characterized the widespread distribution of plastics within the oceans, and invertebrate colonizers/exotic species on larger pieces that could influence the marine ecosystems into which they drift. However, very little information is available on the composition and impact of the microbial communities growing on plastic marine debris.
Full Abstract: Click for Details
Recent studies on plastic marine debris have characterized the widespread distribution of plastics within the oceans, and invertebrate colonizers/exotic species on larger pieces that could influence the marine ecosystems into which they drift. However, very little information is available on the composition and impact of the microbial communities growing on plastic marine debris.To investigate what marine microbial communities develop on plastic marine debris over time, four different resins were submerged in the coastal waters of Woods Hole, MA and sampled 7 times within the first 24 hours, daily for a week, and weekly for a month, totaling 16 samples for each resin type. Microbial colonizers were imaged by scanning electron microscopy and analyzed for type, size, and number of organisms per surface area. Pennate diatoms appeared within the first hour, as quickly as bacteria, and dominated the overall coverage. The number of organisms per square mm increased over time on all substrates, as expected. Different plastics showed different colonization rates and communities, suggesting that the chemical and physical characteristics of individual resins select for different microbial colonizers.
Factors That Influence the Composition of the Resident Macrofauna Community of Free-Floating Sargassum
Nieves, M. A.^; Siuda, A. N.#
The free-floating seaweed, Sargassum , hosts ten endemic and over one hundred associated organisms. Sargassum and its faunal community provide essential nursery and/or foraging habitat for oceanic fish, turtles and seabirds. However, the factors that influence the Sargassum community composition (e.g., organism density and species richness) remain relatively unknown.
Full Abstract: Click for Details
The free-floating seaweed, Sargassum , hosts ten endemic and over one hundred associated organisms. Sargassum and its faunal community provide essential nursery and/or foraging habitat for oceanic fish, turtles and seabirds. However, the factors that influence the Sargassum community composition (e.g., organism density and species richness) remain relatively unknown. We sailed from Puerto Rico to New York via Bermuda, collected Sargassum clumps with a dip net and identified the macrofauna in each clump. We assessed the influence of Sargassum species, latitude, and clump mass on macrofauna community composition. S. natans was more common at higher latitudes and had significantly greater richness than S. fluitans. Similar to previous studies, species richness was greater at higher latitudes and macrofauna density in both Sargassum species increased with clump mass. Conversely, richness was independent of clump mass while density remained independent from latitude. The physical factors imposed by latitude (e.g. temperature) might influence the survival of species on a clump, while space availability limits the density of individuals surviving in the clump. However, "historical accidents" might play a strong role in the diversity of Sargassum macrofauna.
Microbe-Microbe, Microbe-Animal Interactions in the Plastisphere
Zettler, E. R.#; Mincer, T. J.; Slikas, B.; Boyd, G.; Melvin, W.*; Fields, J.; Saleem, K.; Dooley, K.^; Amaral-Zettler, L. A.
The "Plastisphere" encompasses a diverse microbial and metazoan community on plastic marine debris (PMD), now the most common form of debris in the ocean. Colonization experiments with different polymer types offer a window into living interactions in the Plastisphere. We immersed sterile polyethylene, polypropylene, polystyrene, and glass samples in Woods Hole, MA, USA coastal surface waters, and then monitored the development of attached communities on these substrates using quantitative counts of scanning electron micrographs and next-generation amplicon sequencing.
Full Abstract: Click for Details
The "Plastisphere" encompasses a diverse microbial and metazoan community on plastic marine debris (PMD), now the most common form of debris in the ocean. Colonization experiments with different polymer types offer a window into living interactions in the Plastisphere. We immersed sterile polyethylene, polypropylene, polystyrene, and glass samples in Woods Hole, MA, USA coastal surface waters, and then monitored the development of attached communities on these substrates using quantitative counts of scanning electron micrographs and next-generation amplicon sequencing. Microbial populations colonize plastic marine debris quickly, with over 800 species equivalents just one week after immersion, and live microbial cells consistently coat 15-25% of the plastic surface. Different resins initially select for distinct communities, but selectivity decreases after the first month. Nevertheless, there is a clear community succession traceable through at least 4 months. Time series-based network analyses allows for observations in microbe-microbe and microbe-animal interactions such as predator-prey, symbiont-host and parasite-host interactions. Changes in the diversity and composition of communities over time may also provide clues to the age of plastic marine debris, which is currently difficult to determine.
Plastic waste inputs from land into the ocean.
Jambeck, J. R., R. Geyer, C. Wilcox, T. R. Siegler, M. Perryman, A. Andrady, R. Narayan, K. L. Law#, 2015. Science 347, 768-771. doi:10.1126/science.1260352.
December 2014: AGU Fall Meeting
SEA Semester Undergraduates Research the Ocean's Role in Climate Systems in the Pacific Ocean
Audrey Wright Meyer#, Sea Education Association, Woods Hole, MA, United States, Maya Karina Becker^, Columbia University of New York, Palisades, NY, United States, Kalina Cozette Grabb^, Harvard University, Earth and Planetary Sciences, Cambridge, MA, United States and S-250 Scientific Party
Sea Education Association (SEA)’s fully accredited SEA Semester: Oceans & Climate program provides upper-level science undergraduates a unique opportunity to explore the ocean’s role in the global climate system as they conduct real-world oceanographic research and gain first-hand understanding of and appreciation for the collaborative nature of the scientific research process.
Full Abstract: Click for Details
Sea Education Association (SEA)’s fully accredited SEA Semester: Oceans & Climate program provides upper-level science undergraduates a unique opportunity to explore the ocean’s role in the global climate system as they conduct real-world oceanographic research and gain first-hand understanding of and appreciation for the collaborative nature of the scientific research process. Oceans & Climate is an interdisciplinary science and policy semester in which students also explore public policy perspectives to learn how scientific knowledge is used in making climate-related policy. Working first at SEA’s shore campus, students collaborate with SEA faculty and other researchers in the local Woods Hole scientific community to design and develop an original research project to be completed at sea. Students then participate as full, working members of the scientific team and sailing crew aboard the 134-foot brigantine SSV Robert C. Seamans; they conduct extensive oceanographic sampling, manage shipboard operations, and complete and present the independent research project they designed onshore. SEA Semester: Oceans & Climate Cruise S-250 sailed from San Diego to Tahiti on a 7-week, >4000nm voyage last fall (November-December 2013). This remote open-ocean cruise track traversed subtropical and equatorial regions of the Pacific particularly well suited for a diverse range of climate-focused studies. Furthermore, as SEA has regularly collected scientific data along similar Pacific cruise tracks for more than a decade, students often undertake projects that require time-series analyses. 18 undergraduates from 15 different colleges and universities participated in the S-250 program. Two examples of the many projects completed by S-250 students include a study of the possible relationship between tropical cyclone intensification, driven by warm sea surface temperatures, and the presence of barrier layers; and a study of nutrient cycling in the eastern Pacific, focusing on primary nitrite maximum changes in various oceanographic regions with differing levels of stratification and accompanying localization of microbial communities. These studies, as well as additional scientific and policy projects conducted by other Oceans & Climate students, will be highlighted in this poster presentation.
Oligotyping reveals community level habitat selection within the genus Vibrio
Victor T. Schmidt, Julie Reveillaud, Erik Zettler#, Tracy J. Mincer, Leslie Murphy and Linda A. Amaral-Zettler. Front. Microbiol., 13 November 2014 | doi: 10.3389/fmicb.2014.00563
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The genus Vibrio is a metabolically diverse group of facultative anaerobic bacteria, common in aquatic environments and marine hosts. The genus contains several species of importance to human health and aquaculture, including the causative agents of human cholera and fish vibriosis. Vibrios display a wide variety of known life histories, from opportunistic pathogens to long-standing symbionts with individual host species.
Full Abstract: Click for Details
The genus Vibrio is a metabolically diverse group of facultative anaerobic bacteria, common in aquatic environments and marine hosts. The genus contains several species of importance to human health and aquaculture, including the causative agents of human cholera and fish vibriosis. Vibrios display a wide variety of known life histories, from opportunistic pathogens to long-standing symbionts with individual host species. Studying Vibrio ecology has been challenging as individual species often display a wide range of habitat preferences, and groups of vibrios can act as socially cohesive groups. Although strong associations with salinity, temperature and other environmental variables have been established, the degree of habitat or host specificity at both the individual and community levels is unknown. Here we use oligotyping analyses in combination with a large collection of existing Vibrio 16S ribosomal RNA (rRNA) gene sequence data to reveal patterns of Vibrio ecology across a wide range of environmental, host, and abiotic substrate associated habitats. Our data show that individual taxa often display a wide range of habitat preferences yet tend to be highly abundant in either substrate-associated or free-living environments. Our analyses show that Vibrio communities share considerable overlap between two distinct hosts (i.e., sponge and fish), yet are distinct from the abiotic plastic substrates. Lastly, evidence for habitat specificity at the community level exists in some habitats, despite considerable stochasticity in others. In addition to providing insights into Vibrio ecology across a broad range of habitats, our study shows the utility of oligotyping as a facile, high-throughput and unbiased method for large-scale analyses of publically available sequence data repositories and suggests its wide application could greatly extend the range of possibilities to explore microbial ecology.
Second International Ocean Science Conference: Barcelona, Spain
Training the next generation of ocean science and policy leaders by taking them to sea
SEA Faculty Authors: Erik Zettler, Dan Brayton, Erin Bryant, Pamela Coughlin, Deb Goodwin, John Jensen, Paul Joyce, Kara Law, Virginia Land McGuire, Chuck Lea, Mary Malloy, Jason Quilter, Elliot Rappaport, Jeff Schell, Amy Siuda, Jan Witting
Human impact on the environment is one of the most important issues of our time. This conference recognizes that international, multidisciplinary approaches combining science, technology, and governance are critical to address complicated marine challenges. Scientists, engineers, managers, and politicians must learn each other’s “languages” and cooperate to address sustainable utilization, protection, and management of limited marine resources. Ideally, this capacity building begins during university so that upon graduation the next generation making decisions about our global ocean have a broad perspective and are equipped with the skills to communicate and effectively collaborate with colleagues in other disciplines. For 40 years SEA Semester has developed team-taught academic programs combining classroom theory with field experience in marine science, history, and governance.
Full Abstract: Click for Details
Human impact on the environment is one of the most important issues of our time. This conference recognizes that international, multidisciplinary approaches combining science, technology, and governance are critical to address complicated marine challenges. Scientists, engineers, managers, and politicians must learn each other’s “languages” and cooperate to address sustainable utilization, protection, and management of limited marine resources. Ideally, this capacity building begins during university so that upon graduation the next generation making decisions about our global ocean have a broad perspective and are equipped with the skills to communicate and effectively collaborate with colleagues in other disciplines. For 40 years SEA Semester has developed team-taught academic programs combining classroom theory with field experience in marine science, history, and governance. Programs include a 4-7 week voyage aboard a 40m sailing research vessel. Students work in small groups to design, implement, and analyze science research projects and conservation plans to improve ocean health and sustainability for the areas they sail through. They visit international ports to experience different place-based relationships between humans and the sea. Although our boats look like traditional sailing vessels, instrumentation allows students to complete sophisticated research projects and contribute data to local collaborators and international archives. Using the Global Ocean Health Index as a unifying theme, our programs focus on topics including biodiversity, climate change, and sustainability. Sailing in waters from the Mediterranean to New Zealand; we are contributing data to a number of international marine sanctuaries and hope to increase our international collaborations with students and colleagues.
Connectivity in the slender Sargassum shrimp (Latreutes fucorum): implications for a Sargasso Sea protected area
Taylor Sehein^; Amy N. S. Siuda#; Timothy M. Shank; Annette F. Govindarajan Journal of Plankton Research 2014; doi: 10.1093/plankt/fbu081
Conservation groups have called for protective measures in the Sargasso Sea, a region characterized by unique planktonic seaweed communities. To better understand population connectivity and facilitate effective conservation efforts, we assessed slender Sargassum shrimp (Latreutes fucorum) 16S rDNA variation along a 3093-km transect. FST analysis and an analysis of molecular variance indicate a highly dispersive population, suggesting that a network of protected areas may be necessary to protect the Sargassum ecosystem.
Microplastics in the Seas
Law, K.L.#, and R.C. Thompson, 2014. Microplastics in the seas. Science 345, 144-145. doi:10.1126/science.1257426.
Plastic debris in the marine environment is more than just an unsightly problem. Images of beach litter and large floating debris may first come to mind, but much recent concern about plastic pollution has focused on microplastic particles too small to be easily detected by eye.
Distribution of surface plastic debris in the eastern tropical Pacific Ocean from an 11-year data set.
Law, K.#, Moret-Ferguson, S.*, D. Goodwin#, E. Zettler#, E. DeForce, T. Kukulka, and G. Proskurowski. Env.Sci.&Tech.: DOI: 10.1021/es4053076.
Results from the most extensive survey of floating plastic debris in the eastern North and South Pacific Oceans to date resulting from more than 2500 plankton net tows conducted between 2001 and 2012 by SEA Semester students. The distribution closely corresponds to predictions of oceanographic numerical models, with large spatiotemporal variability in plastic concentration. Utilizing all available plankton net data collected in this region, we estimated a minimum of 21 290 t of floating microplastic.
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Seasonal and decadal changes in distribution patterns of Halobates (Hemiptera: Gerridae) populations in the eastern tropical Pacific
Mary Engels#, Liann Correia*, Sarah Piwinski*, Lanna Cheng, Erik Zettler#: Mar.Biol.: DOI: 10.1007/s00227-014-2414-x
Distributions of the marine insect Halobates collected aboard SSV Robert C. Seamans were compared to historical data from 40 years earlier. We observed differences in species distributions over time, but these were not due to climate change. Our analyses show that the patterns observed show substantial but previously undescribed seasonal shifts that occur each year in the ranges of these small water striders. There is substantial overlap in ranges during seasonal shifts, but very little co-occurrence of species in individual net tows, suggesting biological mechanisms rather than physical factors are restricting distribution and co-occurrence.
The article has just been published and is available as ‘Online First’ on SpringerLink. Click to read more.
February 2014 - Ocean Sciences Meeting
Monday, 24 February
A SYNOPTIC LOOK AT EASTERN PACIFIC MICROPLASTIC DEBRIS: 11-YEARS OF CONSISTENT MONITORING
08:15 in 316B: Lavender Law, K.#; Moret-Ferguson, S. E.*; Zettler, E. R.#; DeForce, E.; Proskurowski, G.;
We present Sea Education Association’s extensive survey of floating plastic debris in the eastern North and South Pacific Oceans, comprising more than 2500 plankton net tows conducted on annually repeated cruise tracks between 2001 and 2012.
From these data we define an accumulation zone (25° to 41°N and 130° to 180°W) in the North Pacific subtropical gyre that closely corresponds to several modeled regions of accumulation predicted from the convergence of ocean surface currents. Maximum plastic concentrations from individual surface net tows exceeded 106 pieces km-2, with overall concentrations decreasing with distance from the model-predicted accumulation zone center. Outside of the defined accumulation zone the median plastic concentration was 0 pieces km-2. Spatio-temporal variability in sampling can impose order of magnitude differences in summary statistics, such as mean and median concentrations, calculated over short time periods or limited geographic areas. Such sampling variability also obscures potential trends in plastic concentration over time. Comprehensive monitoring efforts must continue to critically access these biases while synthesizing available data to maintain a dynamic and robust understanding of plastic marine debris.
COMPARATIVE MICROBIAL COMMUNITY STRUCTURE AND BIOGEOGRAPHY OF ATLANTIC AND PACIFIC “PLASTISPHERE” COMMUNITIES
10:30 in 316B: Amaral-Zettler, L. A.; Boyd, G.; Slikas, B.; Zettler, E. R.#; Mincer, T. J.;
Plastic Marine Debris (PMD) is the most abundant form of marine debris found in all of the ocean’s gyres. The Plastisphere is defined as the thin layer of life found on the outer surface of PMD.
Plastisphere microbial communities on microplastics (<5 mm) collected from open ocean surface waters are distinct from the surrounding seawater and harbor a diversity of microbial species including potential pathogens. However, the variability of the Plastisphere over space and time remains underexplored. We completed collection and next-generation amplicon sequencing of 16S rRNA gene V6 hypervariable regions on samples from two open-ocean transects in the North Atlantic Subtropical Gyre and the North Pacific Subtropical Gyre, giving us good data sets for comparing regional differences within and between oceans. Our data reveal that many of the same bacterial Operational Taxonomic Units (OTUs) inhabit the Plastisphere of Atlantic and Pacific gyres, but dominant OTUs are often distinct on different pieces of plastic regardless of ocean basin. Our sampling strategy allows us to compare and contrast Plastisphere biogeography along marine longitudinal and latitudinal gradients.
INVESTIGATION OF MICROBIAL ADHERENCE AND VIRULENCE FACTORS ASSOCIATED WITH OPEN-OCEAN DERIVED PLASTIC MARINE DEBRIS: VIBRIO BACTERIA AS A MODEL SYSTEM (Abstract ID: 16822)
10:45 in 316B: Mincer, T. J.; Guzzetta, V. S.; Slikas, B.; Zettler, E. R.#; Amaral-Zettler, L. A.;
Plastic Marine Debris (PMD) persists much longer than any natural floating substrate and provides an attachment surface for thin layers of life (termed the Plastisphere).
Our previous amplicon sequencing surveys of 16S rRNA genes have shown that Bacteria of the genus Vibrio can comprise a major portion of the Plastisphere – at times nearly 25% of the bacterial community. We adapted a 96-well plate format biofilm quantification assay to survey over 50 Vibrio spp. cultivars for attachment ability to various plastic resins. Some vibrios demonstrated cell density-dependent attachment and/or a preference for plastic resin type. Strikingly, ‘super-colonizer’ vibrios were discovered to form measureable biofilms on plastic in a matter of minutes. In general, biofilm formation phenotypes clustered within Heat Shock Protein 60 (HSP 60) gene phylogenies. We generated a metagenomic dataset of a Vibrio-dominated PMD sample and analyzed it for key adherence and virulence genes. Characterizing Vibrio attachment to plastic will provide a model for PMD colonization and clues to the ecological function of this prevalent group of Plastisphere inhabitants.
MICROBIAL SUCCESSION ON PLASTIC MARINE DEBRIS: DEVELOPMENT OF THE “PLASTISPHERE” COMMUNITY
10:45 in 316B: Zettler, E. R.#; Morrall, C.; Proskurowski, G.; Mincer, T. J.; Amaral-Zettler, L. A.;
Recent studies have revealed a diverse microbial community on plastic marine debris in the Atlantic and Pacific oceans, the so-called “Plastisphere”. How this community develops over time on different types of plastic and in different geographic areas of the world ocean is unknown.
We immersed sterile polyethylene, polypropylene, polystyrene, and glass samples in temperate (Woods Hole, MA, USA) and tropical (St. Georges, Grenada) coastal surface waters, and then monitored the development of microbial communities on these substrates using quantitative counts of scanning electron micrographs and next-generation amplicon sequencing. A variety of pennate diatoms colonized plastic marine debris within the first week and diatoms dominated the early communities in both locations, followed by bacteria. Over time the community changed and other groups such as sessile ciliates colonized the plastic. Communities on expanded polystyrene developed more slowly than on the other substrates, and total coverage increased more quickly in temperate waters than tropical waters. Changes in the diversity and composition of communities over time may provide clues to the age of plastic marine debris, which is currently difficult to determine.
THE REWARDS OF INTERDISCIPLINARY TEACHING IN STEM COURSES: FROM STUDENT TO INSTITUTION
12:15 in 304AB: Goodwin, D. S.#; Schell, J. S.#; Siuda, A. N.#*;
Interdisciplinary teaching and course design encourage critical thinking, promote cognitive development, acknowledge the complexity of real world problems and solutions and, lastly, utilize a problem-solving narrative as the unifying framework providing purpose and relevance to discipline-specific content and methodologies.
Building upon this foundation and aiming to maximize student learning, Sea Education Association (SEA) assembled faculty teams from the traditionally separate disciplines of oceanography, history, policy, and nautical science, to develop 10+ interdisciplinary teaching (IDT) modules. Each IDT module addresses an established marine environmental problem, incorporates problem-solving through a case study approach, emphasizes the challenges and complex pathways inherent in moving towards a solution, and continues to disseminate disciplinary content, skills, and analytical strategies in an integrated way. We will present three IDT modules (iron fertilization, marine debris, and cruise planning in a changing climate) implemented in SEA Semester programs to illustrate their pedagogic components and highlight student outcomes. Most surprising, this teaching initiative, planned for a single course, has guided the evolution of further curriculum design resulting in institution-level change and the development of an entirely new interdisciplinary multi-course semester.
FROM EXPERIENTIAL EDUCATION TO RESEARCH: ENGAGING UNDERGRADUATE STUDENTS IN ONGOING RESEARCH PROJECTS
16:00-18:00 poster session: Amaral-Zettler, L. A.; Yingxin, Y.^; Ong, B.^; Siuda, A. N.#*; Zettler, E. R.#;
Science education combining classroom work with field and laboratory research engages students and can make real contributions to ongoing research projects.
As an example, SEA Semester: Marine Biodiversity and Conservation requires students to take classes combining theory and training in conservation science and policy, including molecular biology, ecological statistics, microscopy, morphology-based taxonomy, conservation planning, GIS, cultural landscape analysis, and marine spatial planning. Students propose a research project that ties into ongoing long-term studies, then live, work, and study aboard a sailing research vessel for 5 weeks to collect samples and data for their projects. Students carry out biodiversity research projects and develop conservation plans for High Seas protection with the Sargasso Sea as a backdrop. Following the first offering of the curriculum, two students continued their research on bacteria associated with plastic marine debris during summer internships in Woods Hole and as part of senior capstone theses at their home campuses. We use these case studies to show how this educational model challenged the students, provided valuable training for their development as young scientists, and contributed to ongoing research projects.
Wednesday, 26 February
SARGASSUM NATANS AND S. FLUITANS EXHIBIT GEOGRAPHICALLY DISTINCT DISTRIBUTIONS IN A 20-YEAR NEUSTON NET DATASET FROM THE WESTERN NORTH ATLANTIC
09:30 in 301AB: Goodwin, D. S.#; Schell, J. S.#; Siuda, A. N.#*;
Sargassum natans and S. fluitans, pelagic drift macroalgae species, are distributed across surface waters of the North Atlantic Gyre (Sargasso Sea), Caribbean Sea and Gulf of Mexico.
These floating ecosystems host diverse biological communities including ecologically and commercially important organisms. As a result, pelagic Sargassum is the focal organism of a new policy initiative to make the Sargasso Sea a high-seas Marine Protected Area. Though observations of Sargassum date back centuries, certain basic questions about distribution and species-specific community composition remain unanswered. This study employs a dataset archived by Sea Education Association (SEA) to examine the distribution and concentration of S. natans and S. fluitans collected from approximately 6000 surface net tows conducted on more than 300 cruises between 1993 and 2013. Distinct seasonal and geographic patterns exist for each species, suggesting that Sargassum in the Sargasso Sea may have multiple source populations each regulated by separate yet overlapping biophysical dynamics. Presently utilized satellite observation methods cannot differentiate between species and thus may not provide sufficient information to guide regional management strategies.
A Review of Observations of Floating Tar in the Sargasso Sea
Peters, A.J., and A.N.S. Siuda. 2014. A review of observations of floating tar in the Sargasso Sea. Oceanography 27(1):217–221, http://dx.doi.org/10.5670/oceanog.2014.25
Floating tar balls are a product of weathering of crude oil in the marine environment. They have been found to be prevalent in the world ocean, particularly in the 1960s and 1970s before stricter controls on petroleum transport and handling were in effect. Much of the early research on the occurrence and composition of pelagic tar balls was conducted in the North Atlantic Ocean. Research and time-series assessments in the Sargasso Sea since that time have documented that floating tar balls sampled by neuston nets in the open ocean and washed up on shorelines have declined in the past two decades.
Two SEA alumni (Edson and Sehein) presented research posters and two SEA faculty members (Siuda and Zettler) presented talks at the 7th annual BioNES (Biology New England South) meeting at Roger Williams University on 6 December:
Ethan Edson (SEA C247/Northeastern Univ.)-Genetic Diversity of Vibrio on Natural Versus Artificial Substrates Across the Sargasso Sea
Taylor Sehein (SEA C241/Northeastern Univ.)-Slender Sargassum Shrimp (Latreutes fucorum) Population Genetic Structure in the Sargasso Sea
Amy NS Siuda-Sargassum sp. Distributions in the Western North Atlantic: Implications for Conservation and Management
Erik Zettler-Life in the ‘Plastisphere:’ The Ecology of Plastic Marine Debris
The results are based on a combination of student projects during the SEA program ‘Marine Biodiversity and Conservation’, current NSF grants, and SEA’s long term data sets.
Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre
Miriam C. Goldstein and Deborah S. Goodwin. PeerJ: DOI 10.7717/peerj.184
The latest research findings from SEA Semester plastic marine debris research by Miriam Goldstein (Scripps Institution of Oceanography) and SEA oceanographer Deb Goodwin describes and quantifies ingestion of plastic particles by Gooseneck barnacles attached to floating marine debris. Miriam and Deb sailed together on SEA Semester trips multiple times and this study integrates samples collected during a Scripps voyage that Miriam led (SEAPLEX 2009), a SEA Semester voyage that Deb led (S-242), and the recent Plastics at SEA 2012 expedition in the Pacific (S243). They found that 33.5% of the 385 barnacles examined had plastic particles in their gut, ranging from one plastic particle to a maximum of 30 particles.
Research Abstract: Click for Details
Substantial quantities of small plastic particles, termed “microplastic,” have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG) since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the “rafting assemblage,” are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp.), which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem.
Life in the "Plastisphere": Microbial communities on plastic marine debris
Zettler, E.R., T.J. Mincer, and L.A. Amaral-Zettler. Env.Sci.&Tech.: DOI: 10.1021/es401288x.
This study of the microbial community that develops on plastic marine debris is based on samples collected during SEA Semester voyages and was published in Environmental Science & Technology. SEA scientists and students are contributing to this collaborative research project between three Woods Hole organizations: SEA, Marine Biological Laboratory, and Woods Hole Oceanographic Institution.
Research Abstract: Click for Details
Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the "Plastisphere". Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. Some Plastisphere members may be opportunistic pathogens (the authors, unpublished data) such as specific members of the genus Vibrio that dominated one of our plastic samples. Plastisphere communities are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean. Plastic has a longer half-life than most natural floating marine substrates, and a hydrophobic surface that promotes microbial colonization and biofilm formation, differing from autochthonous substrates in the upper layers of the ocean.
SEA Semester Marine Biodiversity and Conservation: Improving Stewardship Capacities through Field based Undergraduate Education
John Jensen, SEA (presenter); coauthors Amy Siuda, Sea Education Association; James McDonald Western Michigan University; Caleb McClennen Wildlife Conservation Society; Linda Amaral-Zettler Woods Hole Marine Biological Laboratory; Erik Zettler Sea Education Association
Presented at the 2013 GWS Biennial Conference on Parks, Protected Areas, and Cultural Sites: "Protected Areas in a Changing World", Denver, Colorado • March 11-15, 2013
Research Abstract: Click for Details
The goal of SEA Semester: Marine Biodiversity and Conservation (MBC) is to make a significant and continuing contribution to improved ocean stewardship by developing a new generation of leaders in ocean science and public policy dedicated to understanding, preserving, and restoring our global ocean commons. Funded by NSF and the Virginia Wellington Cabot Foundation, the MBC curriculum integrates science, conservation policy, and place-based management through a field-based study of the potential of the Sargasso Sea as a high seas protected area. The new curriculum combines instruction in classical and cutting-edge techniques in marine biodiversity research, practical tools from conservation, and emergent concepts in placebased management. Initial analyses of first year results suggest a 34-point increase in conservation science and policy content knowledge, improved capacities in written and oral communication, and --most important--an increased engagement and interest among the strongest students in careers related to coastal and ocean stewardship.
Designing a Seabird Observation Protocol for the Sea Education Association
Michael B. Schrimpf*1, Erik R. Zettler1, and K. David Hyrenbach2; 1Sea Education Association, P.O. Box 6, Woods Hole, MA 02543 USA, firstname.lastname@example.org; 2Hawai’i Pacific University, Waimanalo, HI 96795, USA
Presented at the Pacific Seabird Group annual meeting, Portland, OR.
Research Abstract: Click for Details
The Sea Education Association (SEA) is dedicated to marine exploration, understanding, and stewardship, and to the study of humanity's relationship with the oceans. SEA offers high school and undergraduate students an interdisciplinary curriculum, with on shore and at sea components aboard oceanographic sailing school vessels. Cruises are primarily conducted in the tropical and subtropical eastern Pacific Ocean, the northwestern Atlantic Ocean, and the Caribbean Sea. Studies of seabirds on these cruises have been limited in the past, primarily due to constraints of identification for inexperienced students, especially in tropical – subtropical areas of generally low bird abundance. We wish to augment these past efforts by developing standardized survey protocols and identification guides that will allow students to collect meaningful distributional data. Visiting scientists have also participated in some of our past cruises, providing opportunities to collect traditional transect survey data while introducing motivated students to topics in seabird biology and conservation. Our primary goals are to: (1) determine what level of taxonomic identification and ancillary data are both required by researchers and feasible for students, and (2) design a protocol that will enable the collection of survey data valuable for collaborative projects. Another goal of this presentation is to explore whether members of the Pacific Seabird Group research community are interested in joining future SEA cruises.
Sweepstakes Reproductive Success of the Caribbean Spiny Lobster (Panulirus Argus) in the Sargasso Sea
Pivor, J.; Daniel, J.; Siuda, A. N.; Bucklin, A.; Blanco-Bercial, L.; Amaral-Zettler, L.; Zettler, E.
Research talk presented at the ASLO (Association for the Sciences of Limnology and Oceanography) meeting in New Orleans, LA, Feb 2013.
Research Abstract: Click for Details
The Caribbean spiny lobster (Panulirus argus) is widely distributed across the Atlantic Ocean and the fishery is highly economically important. Long-range dispersal of the long-lived planktonic larvae and consequent complex and variable recruitment patterns have generated persistent difficulties in prediction of recruitment and design of effective management strategies. Similar to other highly- fecund and highly abundant marine species, P. argus has lower genetic diversity than expected from abundance and census population size. One explanation may be the Sweepstakes Reproductive Success (SRS) hypothesis, which poses that high variance in individual reproductive success results in smaller effective population size. In particular, SRS predicts less genetic diversity in larval cohorts compared to adult spawning stocks. Life stage and genetic analysis of phyllosome larvae of P. argus collected from the Sargasso Sea has revealed spatial patchiness and genetic differentiation among life stages of similar cohorts. Time/space patterns of population genetic diversity and structure allowed us to test the SRS hypothesis for P. argus and provide new understanding to inform management and policy strategies for this important fishery.
Amy Duarte, an alumna of PEP (Partnership Education Program) presented a poster at the national Society for Advancement of Chicanos and Native Americans in Science (SACNAS) meeting held in Seattle, Washington from October 11-14, 2012. Amy’s poster was based on a research internship she did in collaboration with scientists at SEA, Woods Hole Oceanographic Institution, and Marine Biological Lab:
“Analysis of Plastic in the Sargasso Sea and Vibrio Interactions with Plastic” by Amy Duarte1, Erik Zettler2, Linda-Amaral Zettler3, Tracy Mincer4
(1Humboldt State University, CA, 2Sea Education Association, 3Marine Biological Laboratory, 4Woods Hole Oceanographic Institution, Woods Hole, MA)
April 10, 2012
SEA scientists and students are authors on a new publication in Geophysical Research Letters. Proskurowski. Morét-Ferguson and Law are SEA scientists, and Meyer did this work as an SEA alumnus while enrolled at Eckerd College in St. Petersburg, FL.
Kukulka, T., G. Proskurowski, S. Morét-Ferguson, D.W. Meyer, and K.L. Law. The effects of wind mixing on the vertical distribution of buoyant plastic debris. GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L07601, 6 PP., 2012, doi:10.1029/2012GL051116
SEA Education Association received a National Science Foundation collaborative research grant “Microbial Interactions with Marine Plastic Debris: Diversity, Function, and Fate”. This 3 year project is being directed by Tracy Mincer (Woods Hole Oceanographic Institution), Linda Amaral-Zettler (Marine Biological Laboratory), and Erik Zettler (SEA). The research will use a combination of culturing, molecular biology, and microscope imaging to explore the diversity and function of the unique microbial community that develops on plastic marine debris. The field component of this proposal takes advantage of SEA’s ongoing plastic debris research and is built around independent projects by undergraduate students participating in SEA Semester research cruises in the Atlantic and Pacific Oceans.
Featured Research: Plastics at SEA
Click here to go to the Plastics at Sea Pacific Expedition website.
Since 1971 SEA students and faculty have been sailing and studying the oceans, towing nets to collect planktonic organisms from the surface waters. In addition to microscopic plankton, scientists have found these nets also collect small pieces of floating plastic debris. It was not long before this plastic "trash" was of scientific interest itself.
For more than 20 years SEA has been carefully measuring the abundance of plastic marine debris in the North Atlantic and Caribbean Sea on the sailing oceanographic research vessels SSVs Westward and Corwith Cramer, and also in the North and South Pacific since the arrival of the SSV Robert C. Seamans in 2001.
More than 6150 surface net tows have been carried out from Nova Scotia to the Caribbean Islands, collecting 64,000+ plastic pieces that have been handpicked from net samples. On cruises from Hawaii to the west coast of the U.S. samples have been collected in the much-popularized "Great Pacific Garbage Patch".
Plastic has emerged as a major contaminant in the ocean, yet the most basic questions about its sources, abundance, distribution, and fate in the open ocean remain largely unanswered.
Marine debris poses significant threats to marine life, such as:
injury or death to large marine mammals due to entanglement by large debris
ingestion of smaller plastic debris by seabirds, turtles, and even zooplankton
transport of marine organisms to regions where they may be invasive
plastic materials attracting some chemical pollutants from the ocean, while releasing other harmful compounds into the water
By understanding where in the ocean the plastic collects and the oceanographic reasons why, SEA is taking the first step in tackling these threats to living marine resources.
This work was supported by the National Science Foundation.