"Different fish are all the same: Recruitment strategies of freshwater fishes in dynamic flow environments"
Aquatic Ecologist, La Trobe and Charles Darwin Universities
Abstract: Freshwater fishes need to be able to successfully reproduce and recruit in a wide range of habitat and flow conditions. These flow conditions can vary from stable or static flows to highly variable, sporadic flows, or extremely challenging conditions, such as floods and droughts. Fishes therefore exhibit a wide range of both intra- and interspecific traits and life history strategies for reproduction in response to dynamic and changing flow environments.
Yet despite the enormous diversity of reproductive traits and environmental conditions that freshwater fishes live in, they share enough characteristics to suggest that common drivers influence recruitment strength. This was demonstrated by the recent Riverscape Recruitment Synthesis Model (RRSM; Humphries et al. 2020), which proposes a unifying theoretical model to predict relative recruitment strength for all fishes, in all rivers, under all flow conditions. It assumes that river flow condition is the most influential recruitment driver, but also describes how, where and when other processes (e.g. dispersal, food availability, retention) and species traits (particularly life history) interact to predict recruitment strength.
This presentation will explore using examples mostly from Australian systems, trait or life history responses to flow conditions to enable successful recruitment. It will also discuss the new RRSM and its utility for predicting fish recruitment outcomes in varied flow conditions across systems.
Presenter Background: Alison King is an internationally recognised aquatic ecologist currently based at both La Trobe and Charles Darwin Universities. She has over 20 years of experience specialising in the ecology of Floodplain Rivers, with her main research interests focusing on the importance of freshwater flows in the ecology of fish, particularly fish recruitment, life history adaptations, environmental flows and ecohydrology. She has a strong background in working collaboratively with a range of stakeholders and policy makers to ensure improved management through knowledge generation and adaptive management, particularly in optimising flows for improved ecological outcomes.
Alison has published extensively in peer-reviewed journals, and regularly presents her research at conferences and workshops. She has led several large research projects, often actively working with research users and stakeholders in conducting the research.
She supervises a number of PhD and honours research students. Alison is often invited to participate in relevant scientific and management committees, and has received numerous awards recognising her research achievements throughout her career. Alison is also currently the President of the Australian Society for Fish Biology.
"One way to pass, six ways to fail: toward a mechanistic understanding of fish passage performance and a unified framework for evaluations"
Research Ecologist, United States Geological Survey's S.O. Conte Anadromous Fish Research Center
Abstract: Effective fish passage solutions have evaded fisheries managers and engineers for centuries. Solutions that appear to work in one location fail when applied elsewhere, and even at the same location performance can vary widely across years and species. One cause of this is the complexity of the behaviors that fish must exhibit in order to pass a barrier. In all cases fish must sequentially complete distinct tasks of encountering a passage route, engaging that route (i.e. entry), and finally passing the route once it has been entered. Each of these tasks has rates of success (advance) and failure (retreat), meaning that there are at least six independent, time-based functions that govern passage success. Disentangling these functions is mathematically challenging, but progress made in recent decades has shown that it is both possible and necessary for understanding the causes of passage success and failure. These same techniques also account for effects of varying environmental conditions and migratory motivation. Applied broadly, they can remove the mystery surrounding passage performance: they are an essential tool for adaptive management, and they hold the potential to provide managers with the data they need to develop effective and reliable solutions.
Presenter Background: Ted Castro-Santos is a Research Ecologist at the US Geological Survey's S.O. Conte Anadromous Fish Research Center, where he has worked for over 20 years. Ted has always had diverse interests: he holds dual undergraduate degrees in Biology and Spanish Literature, and got his start in as a lab manager studying physiological ecology of lizards. From there he got his Master's degree doing radio telemetry on small mammals, reconciling bioenergetic costs of thermoregulation with foraging theory. Unable to find work as a weasel tracker, he began working on fish passage at dams in the early 1990's, working first for the hydroelectric industry, then moving to the management side with the US Fish and Wildlife Service, and finally moving to the USGS, where he completed his PhD on fish locomotion and movement, and contributed to the development of the uniform acceleration weir for downstream passage (recipient of the first Fish Passage Conference Project Award). Throughout his career Ted has maintained a strong interest in the interface between physiology and behavior, with a sustained focus on developing and implementing numerical methods that realistically describe the processes of migration and movement. In 2008 Ted partnered with Paul Kemp, Steven Peake, and Eva Enders to develop a series of workshops aimed at bringing together researchers working on fish movement with hydrologists focusing on turbulent flows and geomorphic processes. This led to three international meetings from 2008-2010. This set the stage for the Fish Passage Conference, of which Ted was a founder and where he still serves as a member of the Steering Committee.
"Environmental DNA and its applications in river conservation"
Professor, Universidad de Oviedo (Spain)
Abstract: Environmental DNA is DNA released into the environment by the organisms. In aquatic ecosystems it is used for detection and quantification of species of interest, and also for community inventories. In this talk we will explore its many possible applications in rivers, from fish monitoring to evaluation of water quality, illustrated with a few case studies in dammed rivers. Current technical shortcomings and next challenges will be also discussed.
Presenter Background: Eva currently works as a full Professor of genetics at the Universidad de Oviedo (Spain), where she teaches on marine genomics, biodiversity, evolution and biogeography. Her main research interest has always been conservation biology, especially focused on aquatic ecosystems. She started participating in European projects about Atlantic salmon population biology and conservation in 1991, and followed her research on salmonids, then other freshwater and marine species and communities. The integrity of populations and the impact of anthropogenic disturbances on aquatic species have been two pillars of her research. As a product of her studies she has published more than 270 scientific articles with h-index of 44 and more than 7400 citations. Regarding the impacts of barriers in rivers, she has developed and applied techniques based on environmental DNA for evaluating water quality and river biodiversity above and below dams and reservoirs. In the last years she investigates the ecological and genetic implications of river and marine litter, including microplastics.