Student Seminars Schedule 2018-19

September 7

September 14: Young, O’Farrell

MBE 702 Seminar September 14th at 1:00 PM in SA 103
Below are the two links for the abstracts for MBE702 Friday, Sept. 14, 2018, and new online evaluations for this week's student seminar speakers: Ben Young and Halie O’Farrell. Please tag this email so that you can find it at 1 pm Friday. MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number. Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed.

Ben's evaluation: https://goo.gl/forms/kZO0QqTa9u2CamEZ2
Signatures of disease resistance for the threatened Caribbean branching coral, Acropora palmata
Coral reefs are important ocean ecosystems that provide biodiversity and economic stability. Despite this value, anthropogenic stressors have caused drastic decreases in global coral cover. In the Caribbean, White Band Disease has caused tremendous declines in the critical ecosystem building coral, Acropora palmata. With disease incidence on the rise, an in-depth knowledge of disease resistance dynamics is imperative for conservation efforts. This will allow the persistence of the critical ecosystem functions that A. palmata provides.

Previous observational work with A. palmata genotypes has shown large differences in disease resistance, with percent disease transmission ranging from 0% to 100%. In this study, RNA-seq was used to look at the differential gene expression of 12 A. palmata genotypes with different disease susceptibility in 2016 and 2017. Through the use of 7-day disease challenge experiments, baseline and disease-exposed corals where obtained for RNA-seq analysis. Preliminary analysis indicates strong inter-annual variability between disease exposures in 2016 and 2017. Despite this variation, differential gene expression analysis reveals coordinated transcriptional responses that differ between baseline and disease-exposed corals. This work will contribute to scientifically driven restoration work by informing outplanting efforts of disease resistant genotypes, while also providing the benchmark for a field monitoring experiment of A. palmata on the Florida Reef Tract.

Halie’s evaluation: https://goo.gl/forms/10T34TyWKkBX1Qca2

Comparing shark harvest control rules to potential biological removals when determining total allowable catches
The Magnuson-Stevens Fishery Conservation and Management Act requires fisheries management councils to avoid overfishing by setting total allowable catch (TAC) limits. Currently, shark species’ TACs are set by estimating the relative abundance and projecting forward 20 years under various catch levels while accounting for uncertainty. The TAC is the catch level at which there is a 70% probability that the stock will not be overfished in 20 years. While the use of projections is an established method used for many fish species, it requires data on fisheries history, abundance trends and many life history parameters and involves running complex models with a long computing time. In a climate where more stock assessments and management decisions are being requested in less time with fewer resources, a simpler, more efficient method for determining TACs is needed. Management of protected marine mammals utilized the potential biological removals (PBR) approach to set limits. PBR requires little information and can be computed quickly. Because sharks have a similar life history to marine mammals we explore the possibility of using the PBR method as a more efficient method of establishing TACs. For the purposes of this exploratory work, shark species were limited to those assessed and managed in the south east United States and by the International Commission for the Conservation of Atlantic Tunas (ICCAT). TAC values were extracted from the latest stock assessments for each species, in addition to the information required to calculate a PBR. TAC and PBR values are compared to determine whether the PBR method is a viable alternative to a projection-based TAC.

September 21: Sebastiani, Sirota

September 28: OPEN

October 5: Morris

October 12: Connelly, Randolph

October 19: FALL RECESS

October 26: Kron, Schlenker

MBE 702 Seminar October 26^th at 1:00 PM in SA 103

Below are the two links for the abstracts for MBE702 Friday, Oct. 26, 2018, and new online evaluations for this week's student seminar speakers: Nicholas Kron and Lela Schlenker.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed.
Nicholas' evaluation: https://goo.gl/forms/1MVOpXl3UzYasTfl2

The Stages of Aging: Differential Expression Time Series of Aplysia californica Sensory Neurons

The marine model Aplysia californica (Aplysia) ranks among the most widely used organisms in neuroscience, primarily due to its ability to learn using simple neural circuits. Previously, the transcriptional profiles of sexually mature and aged Aplysia were investigated to determine transcriptional correlates of aging via RNA sequencing (RNAseq; Greer et al 2018). In this expanded study, cDNA from sensory neurons of 76 animals spanning 7 time points (6 months to 12 months), four Aplysia Stages of Aging (juvenile, mature, Aged I, and Aged II) and two identified neuronal clusters (pleural ventral caudal neurons of the pleural ganglia and buccal S cluster neurons of the buccal ganglia) was sequenced on an Illumina HiSeq2500 sequencer for 100 base pair, paired-end sequences.

Differential expression analysis identified 297 significantly differentially expressed (DE) transcripts (p£0.05). Gene ontology annotation of DE transcript revealed significant enrichment (p<0.05) for several categories including divalent inorganic cation homeostasis (GO:0072507) and cellular metal ion homeostasis (GO:0006875), indicating these processes may mediate physiological changes associated with age in Aplysia sensory neurons observed previously. Finally, clustering of the expression profiles of these DE transcripts yielded 8 common transcriptional trajectories with age, revealing the complex activity of several genes that may underlie the aging process.

Lela’s evaluation: https://goo.gl/forms/eAGkQXYdZd3O2XcA3

Why Tag a Captive Fish? Evaluating Spawning Behavior of Mahi-Mahi Using Pop-up Satellite Archival Tags

Mahi-mahi (Coryphaena hippurus, “mahi” in the following) is a highly migratory ecologically and commercially important pelagic fish species. Understanding migration and habitat utilization of highly migratory fishes is paramount to understanding their ecology and concomitant with successful management. To better understand behavior in wild mahi, we used pop-up satellite archival tags (PSATs) to measure acceleration, depth, temperature, and light levels. To model acceleration patterns around spawning we tagged wild-caught captive mahi with PSATs and observed them in captivity. A boosted regression tree model was built to predict spawning events based on observed accelerometry data and time of day. We then deployed 16 PSATs on wild mahi in the Florida straits (FL; n=14) and the Gulf of Mexico (GOM; n=2). The spawning model was applied to PSAT data from wild mahi and the depths and temperatures associated with the potential spawning events were extracted. PSAT light data were modeled using Trackit, a state-space Kalman filter model, to estimate migrations. PSAT data demonstrated that mahi spawn at depth, migrate up to 100 km per day, and inhabit a wide range of temperatures and depths. These data are the first to predict spawning of a wild marine teleost from accelerometry data and a critical component of understanding the ecology of mahi.

November 2: Palacio, Williamson

November 9: Haider, Rusnak

November 17-25: THANKSGIVING RECESS

November 30: Blackout Date (classes end Tues Dec 4)

December 12: SEMESTER ENDS

January 14: CLASSES BEGIN

January 18: OPEN

“Evolutionary origin of the mammalian hematopoietic system found in a colonial chordate”
Dr. Benyamin Rosental, Ben Gurion, University of the Negev

January 25: Brown 

MBE 702 Seminar January 25^th at 1:00 PM in SA 103
Below is the link for the abstract for MBE702 Friday, Jan. 25, 2019, and new online evaluation for this week's student seminar speaker: Julie Brown.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed.

Julie's evaluation: https://goo.gl/forms/uzRg710dUA8kA9p73

Billfish in the Eastern Pacific: Habitat Influence in Recreational Fisheries

Recreational billfish fisheries in Central America show persistently high catch rates in spite declining stock size. However, catch rates are important indices commonly used in stock assessments. In these recreational fisheries, environmental factors influence the catchability component in the catch rates (CPUE). Failure to acknowledge this influence can lead to mistaken interpretation of the status of exploitation of billfish stocks.  In the coastal Eastern Pacific, recreational catch rates for sailfish are seasonal, corresponding to cyclical fluctuations in wind and oceanic features. We used CPUE from highly homogenous fleets/operations to explore the nature of these indices in the recreational fisheries of Costa Rica and Guatemala. El Nino strength signal was used as a broad indicator of the state of ocean dynamics. A significant degree of association was found using Costa Rican CPUEs. The depth of the mixed layer was used as an indicator of the localized compression of habitat for adult sailfish. The average depth of this layer did not statistically influence Costa Rican CPUEs, however Guatemala saw higher catch rates when this layer was shallower. A deeper understanding of the nature of these relationships may lead to more successful sailfish stock assessments in the future.

February 1: Daugherty

MBE 702 Seminar February 1^st at 1:00 PM in SA 103
Below is the link for the abstract for MBE702 Friday, Feb. 1, 2019, and new online evaluation for this week's student seminar speaker: Zack Daugherty.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed. 

Zack's evaluation: https://goo.gl/forms/JB7qWANNKULmRdw43

Review in the Effects of DMS/P and Its Potential Application in Marine Aquaculture

The sulfur containing compounds dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) are infochemicals or chemicals which convey information in interactions between marine organisms over a broad range of trophic levels. Research into these ecologically important infochemicals show the influence on the chemosensory perceptions and behavior of early life stages (ELS) of fish larvae and how they influence navigation to food sources and settlement habitats. Introduction of feeding attractants containing DMS/P have resulted in increased feed consumption and growth in some juvenile species of fish. Traditional marine fish larval culture methods mitigate bacterial loads through filtration resulting in the removal of these compounds. There is little research that explore the effects of DMS/P on feeding incidence, growth and subsequent survivorship of ELS fish larvae in laboratory settings, or where water sources are void of ecologically relevant levels of these chemicals. Failure to account for this removal of DMS/P can lead to a decreased feeding response resulting in increased mortality and depressed growth in ELS of marine fish. This proposed research will explore the potential effects of introducing DMS/P compounds to laboratory culture settings during the ELS of Nassau grouper (Epinephelus striatus), a delicate and difficult to rear marine reef fish species.

February 8: Ehrlich, Recruitment day (planned as of 5-18)

MBE 702 Seminar February 8^th at 1:00 PM in SA 103
Below is the link for the abstract for MBE702 Friday, Feb. 8, 2019, and new online evaluation for this week's student seminar speaker: Moritz Ehrlich.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed. 

Moritz's evaluation: https://goo.gl/forms/JrXQwP8X4CWFhJ4U2

Rapid adaptation via polygenic selection: Seasonal genetic divergence among microhabitats of the killifish, Fundulus heteroclitus.

Increased rates of change and variance in the environment are forcing organisms to adapt at an unprecedented rate. However, it is  unclear whether evolutionarily adaptation can effectively occur on short time scales (<10 generations). Understanding the genetic basis that evolution acts upon may help to explain surprisingly rapid adaptation rates. Polygenicadaptation (allele frequency changes at multiple loci of small effect) may provide a mechanism for rapid, flexible evolutionary response. To provide insights into rapid adaptation in the wild, I investigated the genetic variation among microhabitats within a marine saltmarsh estuary. These microhabitats, specifically coastal basins and tidal ponds, are dissimilar environments: ponds are up to 4°C warmer during daytime, anoxic at night (>12h), and subject to greater predation pressure than the less variable basins. Here I present genomic data on 250 resident Fundulus heteroclitus, contrasting fish from basin versus ponds in spring and fall. I demonstrate genetic divergence among microhabitats as well as habitat-specific seasonal allele frequency changes. I hypothesise that this pattern is the result of selection acting on traits affecting fitness conditional on microhabitat environment. With F. heteroclitus interbreeding at random throughout the estuary, selection and the resulting allele frequency shifts must occur every generation. Such continued genetic load can only be tolerated if selection acts on polygenic traits that require small allele frequency changes at multiple loci of small effect. Preliminary physiological measurements showing divergence between pond and basin residents support the idea that a combination of small allele frequency changes at multiple loci can lead to rapid phenotypic shifts that confer a selective advantage at short, ecological time scales.

February 15: Snyder

MBE 702 Seminar February 15^th at 1:00 PM in SA 103
Below is the link for the abstract for MBE702 Friday, Feb. 15, 2019, and new online evaluation for this week's student seminar speaker: Grace Snyder.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed. 

Grace's evaluation: https://goo.gl/forms/PXv9SvtuodG5wVhN2

The Development of Stem Cell Therapy in Corals

Coral reefs are declining rapidly across the world due to climate change. Intervention strategies using genetic and physiological manipulation are currently being explored as a way to increase coral survival. One such manipulation is stem cell therapy, where populations of weakened or damaged cells can be rebuilt by the introduction of healthy stem cells, which then continuously differentiate into various healthy cell lineages. Stem cells’ ability to rebuild damaged cells in corals has not yet been investigated but has the potential to benefit unhealthy corals impacted by environmental stressors. 

In this seminar, I will present preliminary data on the identification of stem cells in the branching coral Pocillopora damicornis, as well as in the model sea anemone, Nematostella vectensis. In this study, I used methods of microscopy and fluorescence-activated cell sorting (FACS) to identify and isolate individual cell types, including stem cells. Additionally, I will present preliminary data on the transplantation of stem cells into coral and anemone hosts. The successful execution of stem cell therapy in weakened and threatened corals could provide a possible mode of coral restoration and aid in the preservation of coral reefs against climate change.

February 22: Denson

March 1: Pohlot

MBE 702 Seminar March 1^st at 1:00 PM in SA 103
Below is the link for the abstract for MBE702 Friday, March 1, 2019, and new online evaluation for this week's student seminar speaker: Bruce Pohlot.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed.

Bruce's evaluation: https://goo.gl/forms/JaAh8oaOrpSWMiFF3

Is a Recreational Fishing Reserve Area a Viable Option for Guatemala’s Pacific Coast

The Pacific Sailfish (Istiophorus platypterus) is a vital resource to Central American economies along the eastern Pacific Ocean through tourism (recreational catch-and-release sportfisheries) and as retainable bycatch in the commercial (purse seine and longline) fleet. Mortality resulting from capture in commercial fisheries targeting other pelagic species reduces population abundance and negatively impacts economically important recreational catch rates. In this study, we seek to examine the current state of the Guatemala ecosystem for the viability of a recreational fishing reserve area and where this area will have the greatest impact on conservation and access. This objective requires the development of methods to spatially quantify biodiversity and productivity hotspots along the Guatemalan Pacific coast in both the pelagic and demersal ecosystems to better understand the distribution of coastal resources. Further investigation of the oceanographic parameters in the region seeks to examine the physical system acting on such coastal resources causing aggregation and retention within specific biogeographic locations such as the San Jose Canyon. The examination utilizes a combination of hydroacoustic, oceanographic, and trawl survey sampling methods as well as recent sailfish satellite tagging results from the 2018-2019 season. Finally, an exploration of a previous area closure in Costa Rica is examined relative to suggestions made for the Guatemalan study. 

March 8: Van Dover, student’s invited speaker talk at noon

March 9-17: SPRING BREAK

March 22:  Wang, Denson

MBE 702 Seminar March 22^nd at 1:00 PM in SA 103
Below are the two links for the abstracts for MBE702 Friday, March 22, 2019, and new online evaluations for this week's student seminar speakers: Yadong Wang and LaTreese Denson.
Please tag this email so that you can find it at 1 pm Friday.
MBE students - please remember to bring a phone/laptop to seminar to fill out your critique, and don't forget your C number.
Faculty and staff - we hope you will participate in the online form too, but a few paper evaluations will be available if needed. 

Yadong's evaluation: https://goo.gl/forms/czXZ2tzm9ipbjm582

The effects of Deepwater Horizon crude oil on ammonia and urea handling in mahi-mahi (Coryphaena hippurus) early life stages

The Deepwater Horizon (DWH) oil spill resulted in many important fishes, including mahi-mahi, and their embryos being directly exposed to the oil. Developing fish are especially vulnerable to the toxicity of crude oil-derived polycyclic aromatic hydrocarbons (PAHs). In teleosts, yolk sac protein is the main energy source during the development and is catabolized leading to production of ammonia or urea. Although excretion of these waste products is sensitive to oil exposure, we know little about the underlying mechanisms. In this study, we examined the effects of crude oil on ammonia and urea handling in mahi early life stages. Mahi embryos exposed to 29.77-31.51 µg L^-1 ∑PAH exhibited increased urea excretion rates and accumulated tissue urea levels before hatch suggesting that ammonia, which is highly toxic, was converted into the less-toxic urea. All oil-exposed embryos (6.35-31.51 µg L^-1 ∑PAH) showed significantly increased tissue ammonia levels and upregulated mRNA levels of ammonia transporters (Rhag, Rhbg and Rhcg1). However, despite increased accumulation and higher expression of ammonia transporters, the larvae exposed to higher ∑PAH showed reduced ammonia excretion rates. We propose that reduced cardiac output and atrial contractility which occurs during oil-exposure may limit ammonia excretion. Currently, we are testing this hypothesis using morpholino knockdowns in zebrafish.

LaTreese’s evaluation: https://goo.gl/forms/0hk64wHOgdPSKgSA3

The effect of spatiotemporal variation on larval indices used for King Mackerel in the Northern Gulf of Mexico

The assessment of King mackerel in the Gulf of Mexico uses an index for estimating spawning stock biomass; this index is developed using a statistical model that is parameterized by fitting to larval count data from annual plankton surveys. The model used to make the index does not explicitly consider spatiotemporal variation, which is inherent to the larval count data and can influence local population density. Biomass trends can be misrepresented by a model that does not explicitly consider changes in spatial distributions (e.g., migration or ontogenetic shifts). This misrepresentation of estimated trends has been shown to lead to incorrect and uncertain estimates of stock status in the stock assessments, which are used to set management regulations. King mackerel spatial distributions vary over time as adults migrate seasonally and change their distribution based on the quality of their environment. Migrations cause shifts in their spawning locations from year to year, and this then impacts the larval stage as their distribution is dependent on the location of spawning, and the local oceanography. For this study, I use geostatistical models to answer the following question: Will accounting for spatiotemporal variation reduce the uncertainty in the estimates of the index, or indicate new biomass trends?

March 29: CLOSED

April 5: Nuttall

April 12: Wilson, Ovares

April 19: Kaufman, Harvey

April 26: Town hall; classes end