The Department of Estuarine and Ocean Sciences will be hosting Brian Yellen on Wednesday, April 2 from 12:30-1:30. Yellen, MA State Geologist and Research Asst. Prof UMass Amherst, will be discussing “The Importance of Sediment to Northeast Salt Marshes and Threats Posed by Regional Decline in Coastal Sediment Supply.” Please join us for this seminar in SMAST East 101-103 or online via Zoom!

Abstract:

Coastal environments such as salt marshes, shellfish flats, and beaches depend on a continuous supply of sediment to adjust to rising sea levels. For several years, a UMass Amherst based team has been focusing on assessing (1) the dominant sources of sediment to the New England coast, (2) how sediment contributes to salt marsh accretion, and (3) how humans may be reducing coastal sediment supplies in the Northeast US. In this talk, I will first illustrate the relationship between sediment supply and the ability of salt marshes to build vertically, a process that is essential to maintaining a platform elevation above rising sea levels. Second, I will show how coastal bluff slumping and erosion contributes to coastal sediment supply. We use lidar differencing to quantify the amount of sediment being added directly from bluff erosion. Finally, I will conclude by making use of a newly developed satellite remote sensing tool to demonstrate that coastal suspended sediment has been declining in the Northeast US. Our team hypothesizes that extensive coastal armoring is partly to blame for observed decreases in coastal suspended sediment, potentially posing added adaptation challenges to threatened coastal habitats like salt marshes.

The Department of Fisheries Oceanography is hosting Elle Keane, Biologist and Tribal Liaison Officer for the Greater Atlantic Regional Fisheries Office and Asha Ajmani, Tribal Engagement Coordinator at the Northeast Regional Ocean Council on March 5th. The seminar, “Working with Tribal Nations” will be held in SMAST East 101-103 from 3-4. Please join us in person or on Zoom!

Abstract:

The U.S government and the governments of federally-recognized Tribal Nations have a unique government-to-government relationship set forth in the Constitution of the United States, treaties, statutes, and court decisions. Within this relationship, NOAA Fisheries works with Tribal Nations on a range of issues, including habitat, fisheries management, and endangered species, among others. This seminar will provide an overview of this relationship and NOAA Fisheries’ engagement with Tribal Nations in the Greater Atlantic Region. The Northeast Regional Ocean Council (NROC) is a voluntary forum for Tribal, federal, state and NGO partners to form interagency coordination and cooperation on regional approaches to support balanced uses and conservation of the Northeast’s ocean and coastal resources. Recently, NROC launched a Tribal Caucus to identify Tribal interests and needs, and coordinate Tribal guidance on NROC priorities and the implementation of specific NROC projects. These efforts have led to increased Tribal participation in NROC and the development of work groups and other products responding to identified needs.

The Department of Estuarine and Ocean Sciences is hosting Laurel Schaider on Wednesday March 5 for a seminar on “PFAS in the waters of Cape Cod: What do we know and how can we protect water quality?”. The seminar will take place in SMAST East 101-103 from 12:30-1:30 and is available on Zoom.

Abstract:

Per- and polyfluoroalkyl substances (PFAS)—also called “forever chemicals”—are grabbing headlines every day as global environmental pollutants. Closer to home, PFAS are increasingly being discovered in drinking water, surface waters, and groundwater throughout Massachusetts. Groundwater on Cape Cod is vulnerable to PFAS contamination because of the shallow sand and gravel aquifer and dense development. This presentation will provide an overview of the key concerns about widespread PFAS exposure and health effects. We will discuss major sources of PFAS contamination in groundwater and surface waters on Cape Cod, and present key findings from past and ongoing research to discover the extent of PFAS contamination and implications for human and ecological health.

This year’s IMS Symposium will be held March 26 from 9-5 at SMAST East! Register HERE!

The NEW registration deadline date Thursday March 20th at 4:00 PM. We cannot accept any after that time! Please get it done ASAP so you can be sure we have you on there :). If you are planning on presenting, also submit your abstract by March 3rd, you can find the details on the website!

DFO’s own Jessica Kittel will be defending her PhD Dissertation “Environmental Effects on Population Dynamics of New England Yellowtail Flounder” on April 7! Join us at SMAST East, Rooms 101-103 or on Zoom. Check out Jessie’s abstract below!

Abstract:

Yellowtail flounder, Limanda ferruginea (a.k.a., Pleuronectes ferruginea, Myzopsetta ferruginea), inhabit the continental shelf of the northwest Atlantic and historically supported target fisheries off New England. However, the Georges Bank and Southern New England/ Mid-Atlantic stocks have declined in recent decades and have not recovered despite severely restricted fisheries, suggesting that productivity may be negatively affected by climate change. Ocean waters off New England are warming four times faster than the global average, and decreased yellowtail flounder productivity has been associated with ocean warming in the region. US stock assessments of yellowtail flounder have exhibited retrospective patterns, in which contemporary estimates of abundance decrease when a new year of data is added, presenting a major source of uncertainty for determining stock status and informing rebuilding plans. Retrospective patterns may result from model assumptions that do not account for environmental effects on population or fishery dynamics. In the face of climate change, there is increasing exploration of climate impacts on stock dynamics in the context of stock assessments. However, incorrectly integrating climate information can contribute to model misspecification. Thus, it is important to identify significant relationships and understand mechanisms before including them in assessments. Process error refers to the variability in population dynamics due to natural fluctuations (such as environmental effects) not captured by the model. State space models explicitly model this uncertainty, potentially improving the accuracy of assessments and supporting more adaptive, sustainable fisheries management. I led a review of the available information on environmental drivers that may be impacting US stocks of yellowtail flounder from literature and harvesters’ ecological knowledge, tested relationships between environmental indices and components of productivity (i.e., recruitment, growth, maturity, survival), and helped developed stock assessment models that account for environmental effects. Chapter One reviews the available information on environmental drivers impacting stocks of yellowtail flounder off New England from literature and harvesters’ ecological knowledge. Results suggest that several aspects of yellowtail flounder population dynamics have been sensitive to the environment, including geographic distribution, recruitment, and potentially other components of production such as natural mortality and growth. Chapter Two tested relationships between environmental indices and components of population dynamics. Generalized Additive Models (GAMs) were applied to explore relationships between the identified environmental variables and stock dynamics to determine what data should be explored in the yellowtail flounder stock assessment models. Several potential climate impacts were identified. Recruitment of yellowtail flounder off southern New England was correlated to the Mid-Atlantic Bight Cold Pool. Recruitment of yellowtail flounder on Georges Bank was correlated with bottom temperature and the Atlantic Multidecadal Oscillation. Chapter Three developed an assessment model for the Georges Bank yellowtail flounder stock that accounts for environmental effects. Results show that incorporating environmental covariates into the stock assessment improves model diagnostics and reduces uncertainty in short-term projections. This research has implications for improving assessment and management of New England yellowtail flounder fisheries and serves as a model for how appropriate ecosystem drivers can be identified for use in integrated state-space stock assessments for other assessments.

Siddhant (Sid) Kerhalka, PhD candidate in the Tandon Lab here at SMAST, will be presenting on “Impacts of Salinity Stratification on SST in the Northern Indian Ocean Warm Pool “. This seminar will take place Tuesday February 26 in SMAST East 101-103 and on Zoom. We look forward to seeing you there!

Abstract:

Predicting the Indian monsoon at sub-seasonal timescales remains a challenge, hindering accurate global weather forecasting. A precursor to monsoon onset is the formation of high sea surface temperature (SST) “mini-warm pools” in the Indian Ocean during the spring inter-monsoon, characterized by intense diurnal warming, leading to formation of Diurnal Warm Layers (DWL). The spatial variability of SST and DWLs is poorly understood, despite their importance for initiating intense atmospheric convection, particularly during the Monsoon. These variations in SST can occur due to differences in river-influenced stratification, upper ocean optical properties, and air-sea fluxes. Previous high-resolution observations revealed significant (O(1°C)) SST variations over short distances (<100 km) within DWLs for diurnal timescales. Satellite data further showed similar spatial differences in monthly baseline SST increases, even with comparable wind and heat flux forcing. In this talk, we use a 1-D General Ocean Turbulence Model to investigate the role of in salinity stratification, optical properties, and air-sea fluxes in establishing spatial SST variations at diurnal and sub-seasonal timescales. Our results show that while salinity stratification plays a secondary role (12.5-25%) in daily SST variations, it becomes crucial over longer, sub-seasonal periods. A counterintuitive finding emerges: stratified waters heat more than unstratified waters under higher net heat flux conditions, but heat less under lower net heat flux. This implies that density fronts which are primarily driven by salinity can either strengthen or weaken depending on the heat flux and upper ocean optical properties. Because these SST differences occur in typically eddy-poor regions of the Northern Indian Ocean, variations in stratification become a primary driver of both diurnal and sub-seasonal SST variability. This is particularly relevant in areas with strong salinity fronts, like the Northern Indian Ocean, as SST is a critical parameter coupling atmosphere and ocean dynamics through air-sea fluxes.

Kate Masury will be joing us at SMAST East 101-103 on February 26, from 3-4! Kate Masury, executive director at Eating with the Ecosystem, will be discussing “Understanding Seafood Supply Chains: Strengthening Connections Between Fisheries, Markets, and Ecosystems”. Please join us at SMAST or on Zoom!

Abstract:

New England’s seafood supply chains are dynamic and complex, shaped by ecological shifts, regulatory frameworks, and evolving consumer demand. While the region lands an incredible diversity of seafood, much of it is exported, and local markets remain dominated by imports. How can we build more resilient, place-based seafood supply chains that better support both fisheries and communities? This talk will explore these challenges through the work of Eating with the Ecosystem and its efforts to promote a more adaptive, ecosystem-based approach to local seafood. A key focus will be the Markets to Models project, a collaboration with UMass Dartmouth’s School for Marine Science and Technology (SMAST), which is piloting an innovative marketplace model to better illustrate the connections between seafood supply chains, fisheries, and ecosystems. By mapping these connections, the project aims to identify strengths and vulnerabilities within supply chains, providing valuable insights for improving market resilience and sustainability. We’ll examine how strengthening local seafood networks can enhance economic opportunities, promote ecosystem-based management, and increase access to fresh, locally harvested seafood. By rethinking how seafood moves from boat to plate, we can create a more transparent, sustainable, and adaptive future for New England’s fisheries.

The Department of Fisheries Oceanography is hosting David Bethoney, Executive Director at the Commercial Fisheries Research Foundation, for a seminar on “From Data to Discovery: The Lobster and Jonah Crab Research Fleet”. This seminar will take place in SMAST East 101-103 on February 19, from 3-4. If you can’t make it in person, feel free to join via Zoom!

Abstract:

The CFRF Lobster and Jonah Crab Research Fleet project aims to implement a cost-effective method for collecting essential biological data on two commercially important species: the American lobster and Jonah crab. This project utilizes a fishing vessel research fleet approach, where lobster and Jonah crab fishermen gather biological and environmental data during their commercial fishing trips. This presentation on the Research Fleet will consist of two parts. The first part will focus on the development and methods used in the Research Fleet, including results that directly relate to the project’s goals. The second part will highlight extension projects developed from the Research Fleet. These extension projects encompass a variety of topics and involve additional data collection and analysis based on participant interests and feedback from scientists and managers who rely on the data.

The Department of Estuarine and Ocean Science will be hosting Katrina Velle, Assistant Professor in the Biology Department at UMass-Dartmouth on February 19! Dr. Velle will be discussing “The actin cytoskeleton drives cell migration in a model of the “brain-eating amoeba”. This seminar will take place from 12:30-1:30 in SMAST East 101-103 and on Zoom.

Abstract:

The “brain eating amoeba” Naegleria fowleri has a ~95% case fatality rate, and primarily infects children. Despite its clear importance, we have little understanding of the basic cell biological mechanisms that underlie Naegleria’s pathogenesis, which is key information for the identification of new drug targets. What is clear, however, is that actin assembly and disassembly drives many cellular processes in Naegleria. The Velle lab studies how the actin cytoskeleton promotes cell migration, cell division, and osmoregulation—three phenotypes important for establishing and spreading infection. This talk will specifically focus on cell migration. To initiate an infection, Naegleria amoebae must crawl through narrow channels in the skull to reach the brain. To study this process, we expose Naegleria gruberi (a nonpathogenic model system) to different types of confinement including microchannels. Using quantitative microscopy, we show that Naegleria amoebae seek out confinement; after contacting the entrance to a microchannel, cells continue to probe the surface until they get inside. Once cells fully enter these channels, they crawl extremely quickly (up to 100 microns/min) in one direction for millimeters. While migrating in confined environments, cells show hallmarks of “blebbing” motility, in which the plasma membrane detaches from the underlying actin cortex and blisters outward, creating an actin-free protrusion. This is in contrast to unconfined cells, which typically use actin-filled protrusions to crawl. Collectively, these data suggest that once Naegleria amoebae detect an opening to a narrow channel—similar to what they encounter during infection—cells will switch to blebbing motility to crawl quickly and persistently.

Keri Anne Goncalves will be defending her thesis on “Co-occurrence of White Sharks (Carcharodon carcharias) Along Coastal Cape Cod, MA” on March 18th at 2 pm! Join us in person at SMAST East 101-103  or on Zoom!

Abstract:

Periodic aggregation and site fidelity are common occurrences for many terrestrial and aquatic species and is typically driven by resource availability. The white shark (Carcharodon carcharias) is a species driven by such, with aggregation behavior throughout multiple stages of its life history. Juveniles exhibit resource-driven aggregations at nursery sites where they may reside for extended periods of time. Large juveniles, sub-adults, and adults tend to exhibit seasonal residency at aggregation sites along their migration routes. Atlantic white sharks form distinct communities during critical early phases of life, though little is known of spatiotemporal trends during late life stages. Using a five-year acoustic telemetry dataset from eastern Cape Cod, MA, this study investigated spatiotemporal associations between tagged individual white sharks (n=185). Network analysis was applied to acoustic detection data (n=365,880 detections) collected seasonally from 2017-2021 to identify strength of associations between groups or individuals. These analyses revealed sexual segregation and behavioral avoidance over the course of the five-year study. In each year and across all years combined aggregating sharks exhibited overall significant negative co-occurrence patterns. This study finds notable interannual variations in social dynamics as well as associations among male and female sharks across multiple years emphasizing the possibility of sex-specific variations in social behavior.