Virtual Event – Dr. Dave Ebert at the Cabrillo Marine Aquarium Discovery Lecture Series – June 4

 

Dr. David Ebert presents:

"Searching for Lost Sharks"

Cabrillo Marine Aquarium | Discovery Lecture Series

Friday, June 4th, 2021 from 7:00-8:30pm pdt

Register for the free event here

About the speaker:

Dr. Dave Ebert is director of the Pacific Shark Research Center and a member of the SJSU/MLML research faculty. He has devoted his life to studying the ocean's most elusive, dangerous and yet fascinating predator - the shark! His adventurous search for Lost Sharks has taken him from his modest hometown in California to the Emperor’s glorious Palace in Tokyo, the dazzling Skeleton Coast of Namibia, and the vibrant streets of Cape Town. His global explorations have led to the discovery of over 50 new shark species.

 

MLML awards $20,000 in scholarships to 21 graduate students

We are thrilled to announce that this year we were able to award $20,000 in scholarships to 21 of our incredible Moss Landing Marine Labs graduate students in recognition of academic achievement and community service!

Congratulations to all our scholarship awardees and thank you to our generous donors who make these scholarships possible. If you would like to support future SJSU/MLML student scholarships, please consider making a donation to our scholarship fund.

Three MLML students receive COAST Graduate Student Research Awards!

We are thrilled to announce that three Moss Landing Marine Labs graduate students received 2021 COAST Graduate Student Research Awards! Congratulations to Daphne Shen (Vertebrate Ecology Lab), Kinsey Matthews (Fisheries Lab), and Jackson Hoeke (Invertebrate Ecology Lab).

The CSU Council on Ocean Affairs, Science & Technology (COAST) provides these grants to support CSU graduate students engaged in marine, coastal, and coastal watershed research. Many SJSU/MLML students have been funded by COAST over the years, and we are always thankful for the California State University’s strong support for marine science research.

Thesis Defense by Jennifer Tackaberry – May 17 Livestream

 

"Humpback whale, Megaptera novaeangliae, feeding dynamics from the perspective of the individual: Insights from demography, life history, and bio-logging"
A Thesis Defense by Jennifer Tackaberry

The Vertebrate Ecology Lab

MLML Live-Stream | May 17, 2021 at 11 am

Thesis Abstract:

In fission-fusion societies, individuals do not need to conform to a social structure in which their demographic or relatedness dictates their behavioral state or associations. Therefore, studies of fission-fusion societies provide a framework in which to compare the feeding dynamics across demographics unrestrained by stable associations. This study used bio-logger data and surface observations combined with long-term population data from the Gulf of Maine humpback whale, Megaptera novaeangliae, population to better understand the influence of demographics on feeding methods, time spent feeding and determine if a coordinated feeding method, kick-feeding, was a cooperative behavior. The results suggest that demographics did influence the feeding method used and highlighted the need to determine how energetic needs change across the feeding season. The results suggest that kick-feeding was not a form of cooperation. In contrast, demographics and the broader population structure did influence the roles that individuals filled in kick-feeding dyads.  Additionally, females’ extensive use of bottom-feeding, compared to males, suggests that different energetic requirements influence the feeding methods used. Preferential use of the lower water column by mother-calf pairs and pregnant females should be considered in future studies about anthropogenic threats.

Images taken under NOAA permit #981-1707, 775-1875, 605-1607, 605-1904, and 18059

Virtual Seminar – Our Anthropocene Ocean: understanding and intelligently managing the expanding footprint on human activity in our oceans – May 13

 

Doug McCauley, University of California Santa Barbara

Hosted by the Chemical Oceanography Lab

Presenting: "Our Anthropocene Ocean: understanding and intelligently managing the expanding footprint on human activity in our oceans"

MLML Virtual Seminar | May 13th, 2021 at 4pm

Watch the Live Stream here or here

 

 

 

About the speaker:

Douglas McCauley is an Associate Professor at the University of California Santa Barbara and the Director of the Benioff Ocean Initiative. Prof. McCauley is a Sloan Research Fellow in the Ocean Sciences and member of World Economic Forum’s Friends of Ocean Action.

Prof. McCauley has degrees in political science and biology from the University of California at Berkeley and a PhD in Biology from Stanford. He conducted postdoctoral research at Stanford, Princeton, and UC Berkeley. 

Prof. McCauley’s research centers upon using advances in marine science, ocean data, and marine technology to promote ocean health. Incorporating new forms of tech into ocean science is an especially important part of the DNA of research in McCauley’s laboratory. 

Research from the McCauley Lab has been published in leading research journals such as Science, Nature, and the Proceedings of the National Academy of Sciences USA and has been featured in the New York Times, BBC, Time, US National Public Radio, and at the World Economic Forum.

 

Thesis Defense by Gregory Bongey – May 11 Livestream

 

"Relationships between weathering and climate variability in a high-relief tropical region during the ice ages: IODP X363 offshore record of Papua New Guinea"
A Thesis Defense by Gregory Bongey

The Geological Oceanography Lab

MLML Live-Stream | May 11, 2021 at 3 pm

Thesis Abstract:

Changes in the Earth’s climate are closely associated with the changes in the concentration of CO2 in the atmosphere. One process that may play a major role in modulating CO2 availability is the chemical weathering of silicate rocks into clays. Chemical weathering and the associated CO2 drawdown are especially efficient in the islands of the Indonesian Archipelago, including New Guinea, due to the combination of warm, wet conditions and tectonic uplift.  Despite New Guinea’s potential global significance as a major contributor to Earth’s carbon cycle, few studies have addressed its rapid geological evolution and the weathering conditions associated with it during the Pleistocene.

As direct products of weathered silicate rocks, clay minerals are a useful and widespread tool for reconstructing past weathering environments and source rocks. Clay mineral data from New Guinea are limited, with no clay records from the Sepik-Ramu Rivers, the island’s largest river system and one of the largest contributors of sediments to the world’s ocean. Deep-sea sediment cores collected by the International Ocean Discovery Program (IODP) Expedition 363 just offshore of the Sepik River mouth provide an unprecedented opportunity to evaluate the history of chemical weathering in a critical, rapidly-evolving region during the middle to late Pleistocene (the past ~550 kyr). This thesis identified and quantified the relative abundance over time of the clay mineral species in the core record in order to establish the regional weathering conditions, test a recent model of the Sepik’s development from an epicontinental sea to an enclosed river valley, and examine the relationship of tropical weathering rates with sea level change during glacial-interglacial cycles. Additionally, this thesis evaluated weathering microtextures on silt-sized feldspar particles to provide a secondary supporting dataset.

This project processed and analyzed the clay compositions of 124 samples from two IODP Expedition 363 sites: Sites U1484 and U1485, along with 16 samples from Site U1486, a site located further offshore from the Sepik River mouth. Isolated clay fractions from each sample were measured with x-ray diffractometry and quantified as clay percentages using simulation software (NewMod). For the corollary study, fine sand-sized feldspar particles were evaluated for weathering microtextures using a scanning electron microscope.

Overall, the clay assemblage is dominated by illite (~25-62%) and chlorite (~20-62%) with secondary amounts of smectite (~2-26%) and kaolinite (~3-32%), suggesting that mechanical rather than chemical weathering is the dominant mechanism responsible for clay generation in this region, possibly due to the active tectonic setting. The record also shows an increase in chlorite over time, attributed to ongoing tectonic uplift and the associated expansion of high-altitude glaciers and mechanical weathering. In addition, a sharp decrease in illite after the oldest samples is interpreted as the cessation of the diagenetic transformation of smectite to illite.

The clay mineral record also shows short-term compositional shifts—the most notable of which include two shifts in clay abundance from 400-430 ka and 125-140 ka characterized by an increase in smectite and kaolinite and a decrease in illite and chlorite. These shifts coincide with glacial terminations, suggesting that rapid sea level rise during deglaciations may have resulted in the reworking of older and more chemically weathered soils. The 400-430 ka shift also coincides with a unit of coccolith ooze indicative of a pelagic environment. This suggests that in the oldest part of the record, marine deposition and sea level transgression may have both contributed to the short-term enrichment of smectite, whereas later clay mineral shifts were driven mainly by sea level rise. The apparent increase in influence from marine transgressions may reflect increasing areas of lowland created by the filling of the Sepik Basin.  These results highlight the numerous processes controlling tropical weathering and document their changing relative significance throughout the evolution of the region.

Thesis Defense by Justin Cordova – May 12 Livestream

 

"Descriptions of Deep-Sea Catsharks (Pentanchidae: Apristurus Garman 1913) from the Southwestern Indian Ocean"
A Thesis Defense by Justin Cordova

The Pacific Shark Research Center

MLML Live-Stream | May 12, 2021 at 4 pm

Thesis Abstract:

Demon catsharks (Carcharhiniformes: Pentanchidae: Apristurus Garman) are one of the most diverse genera of sharks, with 39 described species. The genus is further divided formally into three subgroups based on morphological characters and molecular phylogenies, and referred to as the brunneus-, longicephalus-, and spongiceps subgroups. Six Apristurus species are considered valid in the Southwestern Indian Ocean (SWIO) where the spongiceps subgroup makes up a third of the species in the area. This study identifies and formally describes two additional Apristurus species in the spongiceps subgroup from the SWIO Ridge based on morphometric and meristic data, and includes re-examination of type specimens of Apristurus species from the North Atlantic and Southwestern Pacific oceans due to their close morphological relationship to one of the species found in the area. In this study, morphological characteristics and meristics, along with multivariate statistical tests, were used to determine that significant differences existed between the putative species, confirming species designations. Overall, two species were identified with the first record of A. ampliceps in the area and one new species, referred here to as A. cf. albisoma. An improved Apristurus identification key for the Western Indian Ocean (WIO) will assist fisheries managers in developing conservation policies for fisheries operating in this area.

Virtual Seminar – Geospatial approaches to tropical fish ecology and management – May 6

 

Erik Franklin, University of Hawaiʻi, Mānoa, HIMB

Hosted by the Ichthyology Lab

Presenting: "Geospatial approaches to tropical fish ecology and management"

MLML Virtual Seminar | May 6th, 2021 at 4pm

Watch the Live Stream here or here

 

 

 

About the speaker:

Erik C. Franklin is an Associate Research Professor at the Hawai‘i Institute of Marine Biology in the University of Hawai‘i at Mānoa who leads a group focused on basic and applied ecological and fisheries research in tropical coastal and marine ecosystems to inform the sustainable management of living resources under a changing climate. His research, teaching, and mentorship involves field, lab, and computational methods including open-circuit and rebreather dive surveys, life history studies, population and stock assessments, MPA design and evaluation, and geospatial, statistical, and simulation modeling for native and invasive marine fishes, corals, invertebrates, and cetaceans with projects in Hawai‘i, American Samoa, Guam, the Commonwealth of the Northern Marianas, Fiji, Indonesia, Palau, and Papua New Guinea. His work has appeared in journals such as Nature Climate Change, Nature Ecology & Evolution, Proceedings of the Royal Society B, Fisheries Research, Canadian Journal of Fisheries and Aquatic Sciences, Journal of Fish Biology, and Corals Reefs with a wide dissemination of results to the public through regional, national, and international newspaper articles and radio interviews. His work has been funded by the NSF, NOAA, EPA, USGS, and private foundations. Dr. Franklin is faculty in three graduate programs at the University of Hawai‘i at Mānoa: Marine Biology, Geography and Environment, and Zoology. He also serves as a Member of the Western Pacific Regional Fishery Management Council’s Scientific and Statistical Committee and a Fellow of the Joint Institute for Marine and Atmospheric Research. He earned a Ph.D. from the University of Hawai‘i at Mānoa, an M.S. from the University of Miami Rosenstiel School of Marine and Atmospheric Sciences, and a B.S. from the University of California at San Diego. When not doing the research thing, he is surfing, doing crosswords, or spending time with family. 

 

Thesis Defense by Matthew Jew – May 5 Livestream

 

"Evaluating the trophic habits and dietary overlap of two deep-sea catsharks (Apristurus brunneus and Parmaturus xaniurus) in central California"
A Thesis Defense by Matthew Jew

The Ichthyology Lab

MLML Live-Stream | May 5, 2021 at 4 pm

Matthew Jew grew up in Southern California and attributes his passion for Marine Science to Mr. Tom Clarke, his science teacher during his senior year of high school.  He attended California State University, Monterey Bay, and graduated Magna Cum Laude with degrees in Marine Science and Mathematics.  As an undergraduate, he worked with Dr. James Lindholm and Paul Clerkin as a research assistant.  He credits Dr. Lindholm for fostering his love for research and SCUBA which led him on his career path to MLML.

During his time in graduate school, he shared his passions for marine research and quantitative analysis by teaching in the Marine Science and Mathematics departments at CSU Monterey Bay.  His research at MLML was very diverse, he has kept busy working on numerous projects with a variety of researchers.  He published a paper with Dr. Dave Ebert that redefined the taxonomic description of Hydrolagus macrophthalmus.  He was a California Sea Grant trainee working with Dr. Iliana Ruiz-Cooley learning to trace Domoic Acid through the food web.  And finally, he was advised on his thesis by Dr. Scott Hamilton, Dr. Gitte McDonald, and Keith Bosley evaluating the trophic habits of two deep-sea catsharks.
Now that his time at MLML is nearing it's end, look for him underwater in the spectacular kelp forests for Monterey Bay!

Thesis Abstract:

In marine communities, there are often multiple species that occupy the same or similar niches. When resources are in short supply, competitive interactions can negatively affect the survival of one or both of the species involved. Understanding the trophic habits and interactions of species helps explain their role in a given ecosystem. Additionally, knowing the trophic habits of targeted or bycaught species captured in fisheries can help to influence management decisions on an ecosystem level. Apristurus brunneus and Parmaturus xaniurus (Family: Scyliorhinidae) are abundant deep-sea predators native to the Northeastern Pacific Ocean. Central California offers a unique opportunity to study these sympatric species in a location where they have large populations and the potential to compete for dietary resources. This study identifies: (1) the dietary composition each predator; (2) what biological and environmental factors are associated with variation in their trophic habits; (3) the trophic level of each species; and (4) the level of trophic overlap and potential for interspecific competition between the two species. To investigate the trophic habits of these two predators, this study used two complimentary techniques: stomach content analysis (SCA) and stable isotope analysis (SIA). Specimen from both species were collected during fishery-independent trawl surveys along the central California coast. Stomachs (for SCA) and dorsal white muscle tissue (for SIA) were removed from sharks after biological and catch data were recorded for each individual, including potential explanatory variables (e.g., depth, latitude, longitude, maturity, season, sex, trawl composition, and total length). Trophic habits and trophic position were calculated for each species independently and the level of trophic overlap between each species were calculated for SCA and SIA. Both shark species consumed the same three major prey groups (shrimp, squid, and fishes), however A. brunneus exhibited a similar preference for all three prey categories, while P. xaniurus placed a disproportional preference for shrimp. Apristurus brunneus diet composition varied with sampling season, latitude, sex, and total length. In contrast, the diet of P. xaniurus only varied with sampling season and total length. The results of the SIA indicated similar results. In A. brunneus, δ 15 N varied with latitude, sex, and total length while δ 13 C varied with latitude and total length. Parmaturus xaniurus’ SIA variation was as a function of total length, latitude, and season for δ 15 N and δ 13 C varied with latitude and season. SCA and SIA metrics indicated that the size of dietary niche was consistently smaller for P. xaniurus. Species with a smaller niche size are considered to implement specialist feeding strategy, whereas a much larger niche (like A. brunneus) would indicate generalist diet. Despite the differences in the size of the dietary niche, both SCA and SIA found significant trophic overlap between the two species, such that P. xaniurus samples are nearly completely contained within the isotopic space of A. brunneus. While there is significant dietary overlap, in order for there to be competition between species resources must be limiting. In central California, resources are likely not limiting and these two species have implemented feeding strategies that maximize their net energy gain even when a strong co-competitor is present. Ultimately, the knowledge gained on the dietary and competitive habits of these two species improves our understanding of their role in the deep-sea ecosystem of central California and this new knowledge will aid managers in the implementation of ecosystem-based fisheries management.