Thesis Defense by Jessica Jang-March 29th

Reproductive strategies of the Big Skate (Beringraja binoculata, Girard 1855)

with evidence of multiple paternity

A Thesis Defense by Jessica J. Jang

Pacific Shark Research Center

Friday, March 29th, 2019 at 12 pm

MLML Seminar Room

Jessica Jang is a master’s student under Dr. David A. Ebert of the Pacific Shark Research Center (PSRC). She graduated from the University of Washington’s School of Aquatic and Fishery Science (SAFS) in a B.S. in Aquatic Fishery and Science and minors in marine biology and quantitative sciences. After graduation, she interned for the WildFish Conservancy in their Grays Harbor juvenile salmon survey in Westport, Washington surveying potential salmon habitats in the region. After being accepted into MLML, she has been working at the Marine Pollution Studies Lab, working on various projects involving pollutants found in fish and bivalves and occasionally volunteering at the Monterey Bay Aquarium.


Thesis Abstract:

Beringraja binoculata is a large skate species commonly caught, raised, and exhibited in public aquaria, especially along the Pacific coast of North America. It is one of two species in the Rajidae family found in the western Pacific able to produce multiple embryos within an egg case. Although recent studies suggest this species might be the most fecund elasmobranch currently known, there are no detailed studies on whether this species’ reproductive strategy is influenced by location and environment (e.g. captive vs. wild). Specimens collected from NOAA Fisheries Resource Analysis and Monitoring Division (FRAM) trawl surveys in 2008 and in 2014-2016 showed evidence that wild egg cases and embryo sizes were larger; 3-4 embryos per egg case were the most common, while 2 was the most common in captivity. Offspring sex ratio was not significant, but more female offspring than males was found in both environments. At approximately 42º North latitude, egg case sizes and embryo numbers peaked suggesting that the region is a suitable habitat to deposit offspring due to strong upwelling conditions from the California current ecosystem. Additionally, captive B. binoculata egg cases (n=10) were raised to observe developmental stages. New morphometric data was added to Hitz (1964) describing the developmental stages of this species. Paternity tests were conducted using microsatellites markers, showing multiple paternity exists within this species and females may store sperm for a minimum of three months in captivity, suggesting that B. binoculata possesses several reproductive strategies.

Thesis Defense by Stephen Pang-April 12th

The effect of sex ratio on the reproductive biology of two sex changing fish (Lythrypnus dalli and Rhinogobiops nicholsii)

A Thesis Defense by Stephen Pang

The Ichthyology Lab

Friday, April 12th, 2019 at 12 pm

MLML Seminar Room

Stephen Pang is a master's student under Dr. Scott Hamilton in the Ichthyology Lab. He graduated from the University of Washington in 2012 with a B.S. in biological oceanography. Prior to starting at Moss Landing Marine Labs, Stephen worked in Idaho and central Washington doing salmonid research. He recently completed the Sea Grant State Fellowship (where he was placed with the Delta Stewardship Council in Sacramento) and has recently joined an environmental consulting firm where he continues his work with salmonids and conservation.

Thesis Abstract:

By targeting the largest individuals in a population, size-selective fisheries can influence the life history traits and population parameters of exploited fish stocks. For protogynous (female-to-male) hermaphrodites, this type of harvest is also sex-selective since it preferentially removes males from the population. These differences in sex-specific survival can lead to populations that are heavily female-biased. While males historically have not been considered a limiting factor when assessing the health of gonochoristic populations, modeling work suggests that reduced male abundance and skewed sex ratios could cause a concomitant decline in the reproductive output of protogynous hermaphrodite populations. This study used two nest-brooding sex-changers, Lythrypnus dalli and Rhinogobiops nicholsii, to examine the effect of operational sex ratio on reproductive and nesting success, growth, and rates of sex change. Fish were outplanted on artificial patch reefs at varying sex ratios and their reproductive output was monitored by photographing eggs laid in artificial nests. Sex ratios ranged from 1:1 to 1:19 male:female. Fish were tagged so that growth and sex change could be determined upon recollection from the artificial reefs. For both L. dalli and R. nicholsii, total egg production, female per capita production, average production per nest, and the number of nests per reef were not affected by sex ratio. By contrast, male per capita production and the percentage of nesting males significantly increased as sex ratios became more female-biased. For R. nicholsii, growth rates were highest for individuals that completed sex change during the experimental period. During the breeding season, the frequency of sex change for R. nicholsii was highest on reefs that were strongly female-biased; there was no effect of sex ratio on the frequency of sex change during the non-breeding season. In L. dalli and R. nicholsii, it appears that males do not limit the reproductive output of heavily female-biased populations—as had been predicted by previous modeling work. Instead, for species that defend demersal nests, intrasexual competition between males (i.e., territory and mate monopolization) or females (i.e. competition for nest space) may limit total production when operational sex ratios are more balanced or more female-biased, respectively. As sex ratios became skewed in favor of females, male-male competition was relaxed and individual males became more reproductively successful; the discrepancy in per capita production between males and females at skewed sex ratios indicates that some females would increase their reproductive success by undergoing sex reversal (as demonstrated by R. nicholsii during the breeding season). It is possible that many of the results on reproductive success from this study are specific to nest-brooding species; this highlights the importance of mating systems and reproductive behavior when considering the impact of fisheries on the population dynamics of exploited populations.

Perspectives on an urban wetland: Berrys Creek, New Jersey- January 24th

Craig Jones, Integral Consulting Inc.

Moss Landing Marine Labs Seminar Series - January 24th, 2019

Hosted by the Geological Oceanography Lab

MLML Seminar Room, 4pm

Open to the public

Dr. Craig Jones is a principal ocean and environmental engineer with 20 years of experience in developing and executing engineering and science projects for government agencies and the private sector to characterize offshore environmental sites. His experience includes riverine, lacustrine, estuarine, and coastal processes involving hydrodynamics, waves, sediment, and contaminant transport. Dr. Jones’ expertise includes the application of state-of-the-science field measurements and modeling analysis to characterize and quantify processes in all aquatic systems. He actively participates in the design of field activities and instrumentation to develop data sets in support of clients’ needs. Dr. Jones is adept at incorporating these data into the most effective levels of analysis, from empirical to numerical modeling, necessary to efficiently address the project needs.

Sediment and contaminant transport in urban wetlands is a complex problem requiring robust tools to characterize. Berry’s Creek in New Jersey is an urban wetland that has undergone a multitude of changes over the past century, many of which resulted in contamination posing unacceptable ecosystem risk. The presentation will outline the field and modeling studies related to the risk assessment and remedial investigation of the Berry’s Creek Study Area wetland. The study goals were to characterize the fate and transport of sediment-bound contaminants in the system. These perspectives are being used to develop remedial strategies that will help reduce the overall risk.

Watch Craig’s MLML Seminar Presentation Below:

How animal social behavior can shape ecosystems-February 7th

Mike Gil, UC Santa Cruz

Moss Landing Marine Labs Seminar Series -February 7th, 2019

Hosted by The Invertebrate Zoology Lab

MLML Seminar Room, 4pm

Open to the public

Dr. Mike Gil, Ph.D., is a National Science Foundation Research Fellow, a TED Fellow, and a National Geographic Explorer. He has led research around the world: from coral reefs in the Caribbean, French Polynesia and Southeast Asia, to ‘microislands’ of plastic garbage, teeming with life, in the middle of the Pacific. Various national and international media outlets have covered Mike’s scientific discoveries. His diverse research efforts are unified by a common goal: better understand how natural ecosystems work, so that we can better sustain the essential services these ecosystems provide to humankind. In addition to his scientific research, Mike is an award-winning science communicator with broad interests in connecting diverse swaths of the public with the process of scientific discovery and all that it offers to individuals and to humankind. The son of an Argentine immigrant, Mike was raised working class by a single mom and was a first generation college student. He knows all too well the barriers that prevent the economically disadvantaged from tapping into the STEM world. Thus, Mike founded and runs, which uses unconventional videos to diversify interest in and access to STEM. By bringing mass online audiences along for the adventures of his career, including run ins with sharks, whales and other underwater wonders, Mike aims to deliver the timely message that science is an exhilarating process of discovery that is truly accessible to all and in the service of all.

Through their presence and even simplest behaviors, animals produce sensory information that is publicly available to influence the behavior of surrounding individuals, even those from different species. While there is a wealth of evidence that social information can strongly affect the behavior, fitness and interactions of organisms, it remains largely unknown how this ubiquitous phenomenon may affect the ecology of the greater system. In this talk, centered on the behavior of mixed-species groups of fish in a tropical coral reef, I present work that integrates novel empirical and quantitative approaches to investigate the role that social information can play in the function and dynamics of natural ecosystems.

Detection of climate change: characterising signal and memory-February 14th

Claudie Beaulieu, UC Santa Cruz

Moss Landing Marine Labs Seminar Series - February 14th, 2019

Hosted by The Chemical Oceanography Lab

MLML Seminar Room, 4pm

Open to the public

About the Speaker
Assistant professor, Ocean Sciences Department, UCSC (since 2018)
Visiting academic, Ocean and Earth Science, University of Southampton (since 2018)
Lecturer, Ocean and Earth Science, University of Southampton (2013-2018)
Postdoctoral researcher, Atmospheric and Oceanic Sciences, Princeton University (2009-2013)
PhD, Water Sciences, INRS-ETE, University of Quebec, 2009
BSc, Statistics, Université Laval, 2003


Natural variability in all aspects of the Earth system – including the climate system and ecosystems – presents a formidable challenge to the detection and quantification of change forced by industrial activities. Error in detection can disrupt concerted efforts to respond to the challenges of climate change, whereas statistically robust quantification informs our understanding of underlying mechanisms of change. The rate of observed climate change results from the superposition of mixed signals such as trends and shifts on variability arising from the memory within the climate system. Statistical methods used to characterize change in time-series must be flexible enough to distinguish these components. In this talk, I present a new methodology that is used to separate different modes of change from memory in global mean surface temperature records. This analysis clarifies a key point in the scientific debate related to the recent “hiatus” in warming. I also discuss the importance of considering memory timescales (i.e. short vs long memory), and highlight regions in the ocean where the routinely assumed short-memory assumption may be problematic and affect detection.

Ecosystem response to physical variability in the California Current: from upwelling to fish to predators- February 21st

Jerome Fiechter, UC Santa Cruz

Moss Landing Marine Labs Seminar Series - February 21st 2019

Hosted by The Physical Oceanography Lab

MLML Seminar Room, 4pm

Open to the public

I will present results from a suite of coupled ocean circulation-ecosystem model simulations and describe the impact of environmental variability at local and regional scales on the broader California Current ecosystem response, ranging from primary production to krill distributions to population abundances and foraging patterns of key forage fish species (sardine and anchovy) and apex predators (sea lions).

Watch Jerome’s MLML Seminar Presentation Below:

The physical side of nearshore ecology:From pH and warming to ocean turbulence-March 7th

Brian Gaylord, UC Davis

Moss Landing Marine Labs Seminar Series - March 7th, 2019

Hosted by The Pacific Shark Research Center

MLML Seminar Room, 4pm

Open to the public

Brian Gaylord conducts research in marine ecomechanics, working at the interface of ocean physics and organismal biology and ecology. He and his students are interested in topics that include physical disturbance by waves, dispersal and settlement of spores and larvae, flow through aquatic vegetation, and consequences for marine life of human-induced changes to the ocean realm. He received his B.S. and Ph.D. from Stanford University, did a postdoc and spent some time as a research scientist at the University of California, Santa Barbara, then came to the University of California, Davis’ Bodega Marine Laboratory. He has been working there since, often with collaborators including a diverse suite of students who are continuously expanding the scope of subjects pursued by his laboratory.


Physical-biological interactions are pervasive in the ocean. We’ll discuss several lines of ongoing work where we examine such interactions, focusing on issues of ocean acidification, thermal stresses in mussel beds, and effects of turbulence on settlement of marine invertebrate larvae.


Watch Brian’s MLML Seminar Presentation Below: