The Science of Extremes

Extreme is a word that can send a climate communicator directly into the swamp: the word extreme is inherently a bit alarming, and vague enough to warrant a multi-sentence qualification when you use it. Even scientists disagree on what this word means and in which context it is appropriate. The major issue with the word, “extreme”, is that it has too many uses, but little distinction between them. For the purpose of this explanation, I’ll speak in the context of global temperature as it relates to body temperature, since it is the most commonly discussed climate change topic. Keep in mind, these concepts related to the word extreme are fully applicable to other environmental factors like precipitation, salinity, dissolved oxygen, and ocean pH

Communicating Climate Change: What Can We Learn from Informal Educators?

Public and higher education traditionally exist in separate spheres. And for good reason – there are different assumptions of prior knowledge, and different goals for informal educators vs. academic researchers. However, when it comes to highly-polarized, unfortunately politicized topics like climate change, the typical response of leaning into the “expert researcher” role only exacerbates the divide between public opinion and the ivory tower. Meanwhile, informal learning centers like zoos, aquariums, and museums have worked more productively towards disseminating climate change knowledge without disturbing societal tensions associated with the topic. So how do they do it? And why aren’t we taking notes

Fresh Ideas for Talking about Ocean Acidification

Our NNOCCI associate, Dr. Scott Doney, along with his colleagues, has recently published an updated review of the effects of ocean acidification on marine ecosystems (see here for a previous review). Read on for a summary of their main findings, and to understand how to apply this information to your communications about ocean acidification to the public. The peer-reviewed article is divided into three sections, as we will mirror here: organismal responses, community and ecosystem effects, and risks to human communities

Sea Slugs Make Climate Evolutionary Choices

Nudibranchs are a type of sea slug known for their beautiful colors and curious incorporation of other animals and plants into their own bodies (e.g. using plant chloroplasts to photosynthesize, incorporating toxins into their cells, and swallowing anemones’ stinging cells whole to place in their own tentacles). But did you know they also have more nuanced advantages in their habitats, most importantly under climate change scenarios: they appear to be incredibly heat tolerant. Nudibranchs are mollusks, which you may recognize as being mostly shelled animals like clams, snails, and oysters. But nudibranchs have lost their shells over evolutionary time, and still inhabit areas that are exposed to extreme environmental conditions (like in the rocky intertidal zone). They can’t swim away, have no shell, and still survive every tidal cycle (where they get exposed to the hot sun and air for hours at a time!) like it’s no big deal

USC Dornsife Scientific Diving: An Analysis of Sargassum horneri Ecosystem Impact

The giant kelp forests of Catalina provide not only a subaquatic wonderland for divers, but also a habitat for countless marine organisms. However, their existence is jeopardized by a number of invasive species, namely Sargassum horneri (hereafter referred to as S. horneri). This species has no common name in English, but is referred to as akamoku in Asia, where it is native (Saccardi). S. horneri and S. filicinum, once thought to be two different strains but recently proven to be both classified as the horneri species by Uwai et al. in 2009, is an invasive seaweed found along the coasts of Southern California, the Channel Islands, and Baja Mexico. It behaves similarly to other invasives of S. CA such as S. muticum, Undari pinnatifida, and Caulerpa taxifolia. S. horneri is found in the intertidal zone and up to depths of 19 m, and exhibits a brown fern-like quality with many air bladders, often growing up to 20 feet (Smith). Its forests can grow to be very dense, blocking out sunlight and stealing nutrients and substrate from native species like the giant kelp. It is very apt at reproducing, as it is capable of self-fertilization (both the male and the female are in one plant) and matures early in its lifespan; this makes for rapid growth and out-competition of native species for resources. S. horneri is an annual species, completing its lifespan in less than a year – the dead individuals, often housing creatures like barnacles, diatoms, invertebrates, and even baby giant kelp plants, drift away carrying reproduction-capable structures of their own to colonize new areas. This colonizing mechanism makes the S. horneri difficult to contain; the amount of beached alga from this species is second only to the giant kelp (Miller). Removal of the S. horneri from S. CA and Baja Mexico is necessary to the livelihood of the natural ecosystem, and the current challenge is how we will accomplish this task

Open Source Solutions in Experimental Design: An Introduction to the Symposium

The Open Science movement has increased dramatically in popularity with deserved calls to action around transparency, access to resources, and inclusion in our field. However, its practical applications within experimental design have been slow to uptake, with researchers unsure where to even start with the dizzying array of open source hardware and software solutions available. The perceived time investment and unknown cost, especially in implementing open source hardware, has stagnated the implementation of inexpensive experimental solutions, but we sought to increase awareness to lower the barrier to participation in this space. While there are countless technical and financial advantages to integrating open source solutions into every biologist\u27s experimental design, we put an emphasis on the “people” part of the equation in our symposium. This symposium championed innovative experimental designs by early career SICB researchers across all fields of biology, from plants to animals, in the lab or in the field, or even virtually engaging with the public and students. The open science movement operates within community norms that champion transparency, continuous development, and collaboration. These values are congruent with the priorities of reducing barriers to participation in science, and we hope our symposium\u27s collection of open source solutions encourages readers to adopt these or other innovative designs into their own experimentation

Virtual Expeditions Facilitated By Open Source Solutions Broaden Student Participation in Natural History Research

From its genesis in the Victorian era as an activity for the elite to today\u27s emphasis on “Big Data” and continuous monitoring, natural history has a prominent role in scientific discoveries for many fields. However, participation in field expeditions is limited by funding, space, accessibility, and safety constraints. Others have detailed the active exclusion of minoritized groups from field expeditions and harm/discrimination faced by the few who do participate, but we provide one solution to broaden opportunities for participation in natural history: Virtual Expeditions. Virtual Expeditions are broadly defined as open source, web-facilitated research activities designed to analyze bulk-collected digital data from field expeditions that require visual human interpretation. We show two examples here of their use: an independent research-based analysis of snake behavior and a course-based identification of invertebrate species. We present a guide to their appropriate design, facilitation, and evaluation to result in research grade data. We highlight the importance of open source technology to allow for longevity in methodology and appropriate quality control measures necessary for projects that include dozens of researchers over multiple years. In this perspective, we specifically emphasize the prominent role that open source technology plays in making these experiences feasible and scalable. Even without explicit design as broadening participation endeavors, Virtual Expeditions allow for more inclusive participation of early career researchers with specific participatory limitations. Not only are Virtual Expeditions integral to the large-scale analysis necessary for field expeditions that generate impossibly enormous datasets, but they can also be effective facilitators of inclusivity in natural history research

Environment-Driven Shifts in Inter-Individual Variation and Phenotypic Integration within Subnetworks of the Mussel Transcriptome and Proteome

The environment can alter the magnitude of phenotypic variation among individuals, potentially influencing evolutionary trajectories. However, environmental influences on variation are complex and remain understudied. Populations in heterogeneous environments might exhibit more variation, the amount of variation could differ between benign and stressful conditions, and/or variation might manifest in different ways among stages of the gene-to-protein expression cascade or among physiological functions. Here, we explore these three issues by quantifying patterns of inter-individual variation in both transcript and protein expression levels among California mussels, Mytilus californianus Conrad. Mussels were exposed to five ecologically relevant treatments that varied in the mean and inter-individual heterogeneity of body temperature. To target a diverse set of physiological functions, we assessed variation within 19 expression subnetworks, including canonical stress-response pathways and empirically derived co-expression clusters that represent a diffuse set of cellular processes. Variation in expression was particularly pronounced in the treatments with high mean and heterogeneous body temperatures. However, with few exceptions, environment-dependent shifts of variation in the transcriptome were not reflected in the proteome. A metric of phenotypic integration provided evidence for a greater degree of constraint on relative expression levels (i.e., stronger correlation) within expression subnetworks in benign, homogeneous environments. Our results suggest that environments that are more stressful on average – and which also tend to be more heterogeneous – can relax these expression constraints and reduce phenotypic integration within biochemical subnetworks. Context-dependent \u27unmasking\u27 of functional variation may contribute to inter-individual differences in physiological phenotype and performance in stressful environments

Temperature and Salinity Sensitivity of Respiration, Grazing, and Excretion Rates in the Estuarine Eelgrass Sea Hare, Phyllaplysia taylori

Highly dynamic environments such as estuaries are home to organisms accustomed to wide fluctuations in environmental conditions. However, estuarine temperature and salinity conditions are expected to shift with climate change, potentially altering plant and animal physiology and consequently their ecological interactions. Phyllaplysia taylori, a sea hare that lives exclusively in nearshore eelgrass beds in the Eastern Pacific Ocean, is a positive ecological interactor with eelgrass by increasing eelgrass productivity through grazing removal of photosynthesis-blocking epiphytes. The central aim of our study is to understand how increasing temperature and salinity are likely to alter that ecological interaction. First, we determined salinity thresholds for survival of P. taylori at 20 °C (typical summer temperature) for 2 weeks, and found that significant mortality occurs at salinity below 25 ppt. Then, we determined respiration rate, grazing rate, and defecation rate of P. taylori following a crossed 2-week acclimation at typical summer low- and high temperatures (18 and 22 °C) and salinities (27 and 33 ppt). P. taylori respiration and grazing rates were elevated under low salinity and high temperature. To determine how P. taylori responds to very warm and extreme summer temperatures, we measured respiration rates at higher temperatures (26 °C—very warm summer and 30 °C—heat shock) and feeding rates following exposure to the 30 °C heat shock. Irrespective of acclimation salinity, P. taylori acclimated to 18 °C were more sensitive to heat shock, as they had a larger increase in respiration rate at 30 °C, and had reduced feeding rates following the 30 °C exposure, whereas there was no reduction in feeding rate in 22 °C acclimated specimens. This study provides the first data on the salinity and temperature sensitivity and metabolic physiology of P. taylori with relevance to their trophic position in the context of eelgrass ecosystems

High Heat Tolerance is Negatively Correlated with Upper Thermal Tolerance Plasticity in North Eastern Pacific Nudibranch Mollusks

Rapid ocean warming may alter habitat suitability and population fitness for marine ectotherms. Susceptibility to thermal perturbations will depend in part on plasticity of a species’ upper thermal limits of performance (CTmax). However, we currently lack data regarding CTmax plasticity for several major marine taxa, including nudibranch mollusks, thus limiting predictive responses to habitat warming for these species. In order to determine relative sensitivity to future warming, we investigated heat tolerance limits (CTmax), heat tolerance plasticity (acclimation response ratio), thermal safety margins, temperature sensitivity of metabolism, and metabolic cost of heat shock in nine species of nudibranchs collected across a thermal gradient along the northeastern Pacific coast of California and held at ambient and elevated temperature for thermal acclimation. Heat tolerance differed significantly among species, ranging from 25.4°±0.5°C to 32.2°±1.8°C (x¯±SD), but did not vary with collection site within species. Thermal plasticity was generally high (0.52±0.06, x¯±SE) and was strongly negatively correlated with CTmax in accordance with the trade-off hypothesis of thermal adaptation. Metabolic costs of thermal challenge were low, with no significant alteration in respiration rate of any species 1 h after exposure to acute heat shock. Thermal safety margins, calculated against maximum habitat temperatures, were negative for nearly all species examined (−8.5°±5.3°C, x¯±CI [confidence interval]). From these data, we conclude that warm adaptation in intertidal nudibranchs constrains plastic responses to acute thermal challenge and that southern warm-adapted species are likely most vulnerable to future warming