This week on the Santa Cruz Naturalist podcast on KSQD Radio, host and SJSU/MLML alumna Emily Donham ’16 sits down with current Ichthyology Lab grad student Kristin Saksa to discuss all things rockfish. Kristin’s research focuses on how climate change stressors will impact larval rockfish.
Three new SJSU/MLML research projects are officially Sea Grant-funded! California Sea Grant has announced funding for a total of seven new research projects led by early-career faculty members throughout the state. The one-year projects focus on two key areas of California Sea Grant’s strategic plan: sustainable fisheries & aquaculture, and coastal resilience. This year, a new partnership with the CSU Council on Ocean Affairs, Science & Technology (COAST) provided non-federal match to new CSU faculty members whose research focuses on supporting the state of California’s highest priority marine, coastal and coastal watershed related needs for scientific information.
SJSU/MLML faculty will serve as PIs on the following three projects:
- Chemical oceanographer Dr. Maxime Grand and co-PI research faculty member Dr. Luke Gardner will lead a new project focused on quantifying volatile bromocarbon emissions from seaweed aquaculture in California.
- Invertebrate ecologist Dr. Amanda Kahn and co-PIs Dr. Kerstin Wasson and Dr. Luke Gardner will investigate the use of energetics and metabolism to enhance Olympia oyster aquaculture and outplanting success.
- Ichthyologist Dr. Scott Hamilton and phycologist Dr. Michael Graham will serve as co-PIs on a new project led by SJSU professor Dr. Maya deVries investigating whether co-culture of seaweeds and shellfish improves shell integrity in farmed red abalone.
Congratulations to all our SJSU/MLML faculty members and their collaborators on these exciting new ventures! Learn more about all seven newly funded research projects here.
Congratulations to SJSU/MLML alumna June Shrestha on her selection as a 2021 California Sea Grant State Fellow!
This competitive program matches recent grads with municipal, state, or federal host agencies in California for year-long fellowships that provide training at the interface of science, communication, policy, and management. June received her MS in Marine Science from Moss Landing Marine Labs in 2020 and will be working with NOAA Channel Islands National Marine Sanctuary for her fellowship. June will support efforts to revise the sanctuary management plan, facilitate engagement with stakeholders during sanctuary advisory council meetings, and contribute to education and outreach initiatives.
Read more in the California Sea Grant State Fellowship announcement.
SJSU/MLML Professors Michael Graham of our Phycology Lab and Scott Hamilton of our Ichthyology Lab have received new grant funding from California Sea Grant. Their project titled “Assessment of practical methods for re-establishment of northern California bull kelp populations at an ecologically relevant scale” will focus on restoring native seaweed populations and combatting destructive sea urchin overgrowth.
This grant is one of six funded by California Sea Grant as part of their 2020 Kelp Recovery Research Program. Together the grants total $2.1 million and are funded jointly by California Sea Grant and the California Ocean Protection Council, in collaboration with the California Department of Fish and Wildlife.
Read more about Dr. Graham and Dr. Hamilton's new research project here.
We would like to extend a warm welcome to new SJSU/MLML postdoctoral research associate Dr. Shelby Ziegler! Shelby just completed her PhD at the University of North Carolina Institute of Marine Sciences where her research focused on coastal habitats and fish communities.
At MLML, she will be working with the Fisheries & Conservation Biology and Ichthyology Labs on a project evaluating the performance of the statewide Marine Protected Areas system for enhancing fisheries production and communities. Welcome to Moss Landing, Shelby!
MLML alumnus Evan Mattiasen recently published the results of his thesis research in the journal Global Change Biology!
This study, co-authored by SJSU/MLML Ichthyology Lab professor Dr. Scott Hamilton and CSUMB professor Dr. Cheryl Logan, examines the effects of low oxygen conditions (hypoxia) on rockfish behavior and physiology. The results of this study are particularly relevant for fish stock management in light of global climate change, which is predicted to increase the frequency and severity of hypoxia.
Read Evan’s paper, titled "Effects of hypoxia on the behavior and physiology of kelp forest fishes", here: https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15076
California Sea Grant today announced funding for a total of 19 new research projects that will take place over the next one to two years. A total of $900,000 will go to 19 research projects led by California investigators and graduate students. We are PROUD to announce that our professor of ichthyology, Dr. Scott Hamilton, is one of the grant recipients. This year for the first time, CA Sea Grant solicited project proposals directly from graduate students. We are therefore doubly PROUD to announce that Dr. Hamilton's student Katherine Neylan, is also a recipient thanks to the graduate fellowship in aquaculture.
Development of techniques for the cultivation of monkeyface pricklebacks as a sustainable alternative to unagi
For this project, Dr. Hamilton is interested in using a local fish, the monkeyface prickleback, as a farmed and sustainable alternative to unagi (the seafood cuisine of sea urchins). Co principal investigators include our phycology professor, Dr. Mike Graham, as well as, Dr. Luke Gardner both a research faculty member and the CA Sea Grant Aquaculture Specialist.
Eat your greens: Evaluating microalgae supplemented feeds for sablefish nutrition and growth
Ichthyology student, Katherine Neylan will study the nutrition and growth of sablefish given a microalgal diet. Currently, farm-raised fish rely on a diet that is heavily dependent on the use of forage fish in fish meal and fish oil. However, allocating the proper nutrients to a farmed fish via ocean resources can place a significant strain on forage fish stocks. The project therefore seeks to formulate a diet that incorporates algae and meets nutritional needs while also examining the palatability and digestibility of it for sablefish.
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
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.
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.
Geographic and habitat-based variation in Lingcod (Ophiodon elongatus) demography and life history along the U.S. West Coast
A Thesis Defense by Laurel Lam
Tuesday, December 4th, 2018 at 12pm
MLML Seminar Room
Laurel is a Master's student under Dr. Scott Hamilton in the Ichthyology Lab. She graduated from UC Santa Barbara with a B.S. in Aquatic Biology and spent several years working for the CA Department of Fish and Wildlife and the Aquarium of the Bay in San Francisco before starting her master's at MLML. Laurel came into the master's program with an interest in fish population biology and working with local fishing communities, so studying Lingcod life-history along the U.S West Coast seemed like the perfect thesis project for her. Throughout her master's career, Laurel has worked closely with state and federal fisheries agencies and has volunteered on several annual research cruises conducted by the NOAA Northwest Fisheries Science Center. In addition, she assisted with conducting entrainment and impingement surveys at the Moss Landing Power Plant with Tenera Environmental and currently works with the Marine Pollution Studies Lab as part of the Bioaccumulation Oversight Group, which investigates harmful levels of organic and man-made contaminates in recreationally caught sportfish in California.
Fish populations are known to exhibit spatial variability in life history demography due to factors such as temperature, productivity, habitat, and fishing pressure. However, most stock assessment methods neglect to account for these differences and assume that life history traits are constant and unchanging across space and time. As a result, stocks are managed across broad geographic areas with catch quotas, size limits and other regulations applying equally in all places, running the risk of over- or under-harvesting on a regional scale. In this study, Lingcod (Ophiodon elongatus) were collected throughout their U.S. range from 7 geographically distinct areas (Alaska to Southern California) and two habitat types (high-relief versus low-relief) in collaboration with volunteer anglers, recreational party boats, and the federal West Coast Groundfish Bottom Trawl Survey. I evaluated and compared regional and habitat-based differences in Lingcod size and age structure, growth parameters, timing at 50% maturity, total mortality rates and condition indices. Size structure, growth, and maturity rates were found to exhibit a latitudinal cline, where Lingcod in northern waters grew faster and larger, matured at larger sizes than Lingcod in southern waters. There was no latitudinal trend in total mortality, however, Lingcod from Southern California and Washington had the highest total mortality rates compared to all other regions. Between habitats, Lingcod from rocky high-relief habitats grew faster and larger, matured at smaller sizes, and had higher total mortality than fish from trawlable, low-relief habitats. Condition differences were not significant between habitats and did not follow a latitudinal trend, however Lingcod in the Southern California region were in the best condition. Overall, these findings demonstrate significant latitudinal and habitat-based variability in life history and demography of the West Coast Lingcod stock. Differences in growth, maturity, and condition appear to be strongly linked to coastwide patterns seen in sea surface temperature and productivity, while differences in total mortality and demography seem to be influenced by historic and current fishing pressure.