PLENARY LECTURERS – Larval Fish Conference

Plenary Speakers

Alexandra Teodósio

Maria Alexandra Teodósio is an Associate Professor at University of Algarve and a researcher at CCMAR, where she leads the group “Ecology and Restoration of Riverine, Estuarine and Coastal Habitats”. Her research focuses on estuarine ecology and biological oceanography. Nowadays, she is involved in several projects in Africa coastal areas connecting marine ecosystem health with quality of life of local population.

Catriona Clemmesen

Catriona Clemmesen is a senior scientist at GEOMAR (Helmholtz centre for Ocean Research) in Kiel, Germany and leader of the “Larval Fish Ecology group”. The main aim of her research is studying the effects of temperature, salinity, pH (ocean acidification), ocean currents and genetic background on growth, biochemical condition, survival and recruitment of commercially important fish eggs and larvae.

Chris Chambers

Chris Chambers is a senior research fishery biologist and leader of the Life History and Recruitment Group at the National Oceanic and Atmospheric Administration (NOAA) Fisheries Laboratory at Sandy Hook, New Jersey, USA. His research interests are directed towards the pattern, sources, and consequences of phenotypic variation in wild and captive populations of marine fishes in changing oceans.Chris is a past president of the Early Life History Section of the American Fisheries Society and has served the Section as the Time and Place Committee Chair for the last 20 years.

Jeff Leis

Jeff Leis has a BSc in Zoology from University of Arizona and PhD in Biological Oceanography from University of Hawaii, where he became interested in fish larvae. In 1979, a 2-year fellowship brought him to the Australian Museum from where he retired in 2014. Jeff continues research at the Institute for Marine and Antarctic Studies, Tasmania. His larval-fish research has received awards from American, Australian, Japanese and International organizations

Lee A. Fuiman

Lee A. Fuiman is a Professor in the Department of Marine Science at The University of Texas at Austin and Director of the Fisheries and Mariculture Laboratory at the University of Texas Marine Science Institute. He holds the Perry R. Bass Endowed Chair in Fisheries and Mariculture. He has broad research experience that ranges from freshwater and marine fish eggs and larvae to deep-sea clams, octopus, whale sharks, and Antarctic seals and from taxonomy and systematics, to fisheries and food webs and physiology and behavior. He also plays more than a little volleyball.

Dominique Robert

Robert Dominique is a professor of fisheries ecology at the University of Québec at Rimouski, Canada. A large portion of his research program focuses on the drivers of variability in larval fish survival and recruitment, such as feeding success. For more than 20 years, he has been exploring the importance of prey selectivity during the early larval stage, and its implications for revealing the relationships linking feeding success to growth and survival.

Plenary Abstracts

ALEXANDRA TEODÓSIO

How do the temperate pelagic fish larvae recruit to a suitable habitat (i.e. find a home)?

A series of complementary hypotheses have been proposed to explain the recruitment of marine and temperate pelagic fish larvae originated from pelagic eggs in coastal environments. In this talk, we present a complementary hypothesis describing the biophysical processes intervening in the recruitment of temperate fish larvae into estuaries. This hypothesis, the Sense Acuity And Behavioral (SAAB) hypothesis, recognizes that recruitment is unlikely if the larvae drift passively with the water currents, and that successful recruitment requires the sense acuity of temperate fish larvae and their behavioral response to the estuarine cues present in coastal areas. We propose that temperate fish larvae use a hierarchy of sensory cues (odor, sound, visual and geomagnetic cues) to detect estuarine nursery areas and to aid during navigation towards these areas.

CATRIONA CLEMMESEN

Direct and indirect effects of ocean acidification on herring (Clupea harengus) and cod (Gadus morhua) larvae – a comparative approach

Rising atmospheric CO₂ levels and resulting changes in ocean pH (ocean acidification) have been shown to significantly affect the early life stages of fish with consequences relating to their recruitment potential. Results from laboratory and large-scale mesocosm experiments, where fish eggs and larvae are kept at different levels of CO₂, representing future climate change scenarios, are evaluated focussing on growth, energy allocation, survival, behavioural responses, otolith and bone formation, tissue damages as well as gene expression analyses. Using large-scale mesocosm experiments indirect effects relating to changes in the food web were analysed and indicated potential compensatory mechanisms due to increased food availability. Results from parental acclimation experiments and from a latitudinal approach, comparing the same species from different sampling locations, showed adaptation potentials to CO₂ stressors. Overall, the analyses of the responses of herring and cod larvae, commercially and ecologically very important species in marine, temperate regions, showed some species-specific responses. Additionally the environment experienced by the parents highly influenced the response of the fish larvae to the CO₂ stressor. By using modelling approaches to upscale the experimental results, the consequences of increased CO₂ levels on the fish population are evaluated.

CHRIS CHAMBERS

The Shape of Things to Come: Resiliency of Marine Fish Early Life-Stages in a Changing World

Knowledge of how early life-stages of marine fishes respond to environmental variation is fundamental to understanding population recruitment, adaptive potential of individuals, and the likelihood of persistence of a species in a changing world. Our planet continues to be subjected to ever increasing levels of impacts from human activities with the extent and severity of biological responses expected to increase. Nursery habitats used by many marine fishes are under a myriad of environmental threats associated with these activities including changes in thermal, oxygen, and CO₂ regimes, and the introduction of persistent industrial contaminants. Revealing biological response functions to these challenges provide fisheries ecologists a means to glimpse into future recruitment and to identify optimal conditions for production in an aquaculture context. This presentation provides an overview of the principles of phenotypic responses to environmental challenges, the experimental approaches to revealing the occurrences and patterns of these effects, and the types of biological responses that might be expected in species subjected to these challenges.

JEFF LEIS

Dispersal-relevant behaviour of fish larvae – measuring it, putting it into models and using a dispersal model incorporating behaviour

Since the mid 1990s “the simplifying assumption” that marine fish larvae could validly be treated as passive particles whose dispersal was totally dependent on currents has been gradually discredited by increased understanding of the behavioural capabilities of the larvae. This has led to a generally accepted view that dispersal of marine fish larvae is a biophysical process dependent on both currents and larval behaviour. Yet, many contemporary dispersal models still fail to incorporate behaviour of larvae. This talk provides a historical perspective on larval-fish behavioural research over the past 30 years, and how behavioural data can be obtained and incorporated into dispersal models. Including the ontogeny of behaviour is essential as is incorporating behavioural variation at both within and among individual levels. Examples of questions that can be addressed with a validated dispersal model incorporating behaviour will be provided.

LEE A. FUIMAN

How Did We Get So Far From Where We Began? Looking Back on Our Team’s Research on Maternal Effects

Research projects usually end with new questions. When those questions are pursued in subsequent projects and the cycle repeats, we can find ourselves far from where we began. More than a decade ago, we were investigating the causes of variation in performance of survival skills in red drum (Sciaenops ocellatus) larvae. We found evidence for effects of the quality (not quantity) of maternal investment in eggs on larval performance. What causes such variation in investment? What are the effects of varying maternal investment on larval performance? Can the effects be compensated? Which physiological pathways in larvae mediate the maternal effects? Do any of these findings apply to other species? What are the ecological consequences? Are there practical applications? This presentation will provide an overview of one team’s research on maternal effects and how we went from predator-prey interactions and recruitment mechanisms to lipid physiology, nutrition, metabolic programming, transcriptomics, food-web ecology, climate, aquaculture, and stock-enhancement.

DOMINIQUE ROBERT

The importance of prey selectivity for revealing relationships linking prey availability to larval feeding success and survival potential

More than 100 years ago, Johan Hjort (1914) proposed the Critical Period hypothesis, which stated that strong year classes emerged when first-feeding larvae encountered large numbers of planktonic prey. Over the past decades, fishery scientists have tested the link between recruitment strength and plankton abundance, but very few studies have reported significant relationships. In this keynote address, I argue that the link between plankton abundance and larval survival remains concealed by the lack of knowledge of larval prey preference. While larval fish have long been considered generalist feeders, recent studies have shown that the vast majority of larval fish species are strongly selective from the first-feeding stage, and that a limited number of prey taxa are targeted by multiple larval fish species. I conclude that species-specific knowledge of prey preference is crucial to define the effective prey field and reveal relationships among zooplankton abundance, larval survival potential, and recruitment variability.