The effects of biomechanical and ecological factors on population and community structure of wave-exposed, intertidal macroalgae

I examined the biomechanical factors that influence the sizes of intertidal macroalgae by studying a population of Fucus gardneri at Fogarty Creek Point, OR. I constructed a mathematical model to predict optimal sizes and probabilities of survival for Fucus under conditions of high and low wave exposure. Predicted optimal sizes of Fucus closely matched the mean observed sizes of plants collected from wave-exposed and protected locations. To test this hypothesis in the field, I reciprocally transplanted Fucus between wave-exposed and wave-protected sites and found that the degree of wave exposure did not affect survival, but did influence size. Large Fucus were tattered by waves at exposed sites, and small Fucus grew at protected sites. These results support the hypothesis that wave forces can set mechanical limits to size in Fucus. I experimentally examined the relative influences of wave-induced disturbance, competition and predation on the sea palm, Postelsia palmaeformis and its understory community at a wave-exposed site at Depoe Bay, OR. Postelsia recruitment was affected by seasonal variations in disturbance and was greatest in areas disturbed in winter. Postelsia were most abundant at mid-zone, wave-exposed sites, and their restriction to wave-exposed sites seems to be due both to; 1) the occurrence of predictable winter disturbances at these sites which remove mussels, thereby stimulating sea palm growth from the underlying rock, and 2) high water motion which enhances sea palm growth by increasing nutrient exchange and photosynthesis and preventing desiccation at low tide. Competition, disturbance and grazing were all important factors in structuring the Postelsia understory community. Postelsia were dominant competitors and their holdfasts overgrew low-lying plants which were torn loose with Postelsia when this kelp was dislodged by winter storm surf. In the absence of this predictable, seasonal disturbance, competitive understory species, such as Corallina dominated primary space. Intermediate levels of disturbance allowed for the highest understory species diversity. Limpets played a keystone role by grazing Postelsia, the competitive dominant during most of the year, and maintained high levels of species diversity in the algal understory

Where the Weird Things Are: A Collection of Species Range Extensions in the Southern California Bight

A large-scale monitoring program associated with the establishment of a marine protected area network in southern California provided an opportunity to observe and document unique or rare species across the region. Scientists and students from several educational and research institutions surveyed 145 subtidal reefs, 39 intertidal reefs, and five sandy beaches from 2011-2017, a period of time where oceanographic and climatic conditions changed serially and dramatically. In conjunction with an increase in monitoring frequency and locations, dramatic shifts in oceanographic climate during this same time period likely caused shifts in tolerable habitat conditions for many nearshore species. Here we describe range extensions – both to the north and south – of fourteen marine fish, invertebrate, and algae species as observed during the 2011-2012 South Coast MPA Baseline Program and subsequent monitoring efforts

Identification and phylogenetic comparison of p53 in two distinct mussel species (Mytilus)

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 140 (2005): 237-250, doi:10.1016/j.cca.2005.02.011.The extent to which humans and wildlife are exposed to anthropogenic challenges is an important focus of environmental research. Potential use of p53 gene family marker(s) for aquatic environmental effects monitoring is the long-term goal of this research. The p53 gene is a tumor suppressor gene that is fundamental in cell cycle control and apoptosis. It is mutated or differentially expressed in about 50% of all human cancers and p53 family members are differentially expressed in leukemic clams. Here, we report the identification and characterization of the p53 gene in two species of Mytilus, Mytilus edulis and Mytilus trossulus, using RT-PCR with degenerate and specific primers to conserved regions of the gene. The Mytilus p53 proteins are 99.8% identical and closely related to clam (Mya) p53. In particular, the 3′ untranslated regions were examined to gain understanding of potential post-transcriptional regulatory pathways of p53 expression. We found nuclear and cytoplasmic polyadenylation elements, adenylate/uridylate-rich elements, and a K-box motif previously identified in other, unrelated genes. We also identified a new motif in the p53 3′UTR which is highly conserved across vertebrate and invertebrate species. Differences between the p53 genes of the two Mytilus species may be part of genetic determinants underlying variation in leukemia prevalence and/or development, but this requires further investigation. In conclusion, the conserved regions in these p53 paralogues may represent potential control points in gene expression. This information provides a critical first step in the evaluation of p53 expression as a potential marker for environmental assessment.AFM was supported by the Greater Vancouver Regional District, BC, Canada, and RLC was supported by STAR grant R82935901 from the Environmental Protection Agency (USA)

Community Responses to Climate-Related Variability and Disease: The Critical Importance of Long-Term Research

A major goal of the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) has been to understand the impacts of climate change and variability on the coastal ecosystems of the inner shelf of the California Current Large Marine System in particular, and other marine and even nonmarine systems more generally. Insights can result from determination of impacts of climatic perturbations such as the El Niño-Southern Oscillation, the North Pacific Gyre Oscillation, and the Pacific Decadal Oscillation, as well as impacts of climate-related surprises on populations, communities, and ecosystems. To gain insight into warming impacts at organismal levels, we also investigated mechanistic suborganismal (physiological, molecular) responses to thermal conditions. Warmer water was connected to changes in ecological subsidies, growth of dominant space occupiers (mussels and barnacles), and heightened physiological stress impacts. Fortuitously, PISCO researchers were ideally positioned to document ecosystem vulnerability and resilience to an unprecedented ecological surprise—coast-wide collapse of keystone predator (sea star) populations—and to investigate its consequences. As these examples suggest, long-term sampling is critically important for helping society anticipate and adapt to present and future disruptions caused by global change

The three-dimensional architecture of Hox cluster silencing

Spatial chromatin organization is emerging as an important mechanism to regulate the expression of genes. However, very little is known about genome architecture at high-resolution in vivo. Here, we mapped the three-dimensional organization of the human Hox clusters with chromosome conformation capture (3C) technology. We show that computational modeling of 3C data sets can identify candidate regulatory proteins of chromatin architecture and gene expression. Hox genes encode evolutionarily conserved master regulators of development which strict control has fascinated biologists for over 25 years. Proper transcriptional silencing is key to Hox function since premature expression can lead to developmental defects or human disease. We now show that the HoxA cluster is organized into multiple chromatin loops that are dependent on transcription activity. Long-range contacts were found in all four silent clusters but looping patterns were specific to each cluster. In contrast to the Drosophila homeotic bithorax complex (BX-C), we found that Polycomb proteins are only modestly required for human cluster looping and silencing. However, computational three-dimensional Hox cluster modeling identified the insulator-binding protein CTCF as a likely candidate mediating DNA loops in all clusters. Our data suggest that Hox cluster looping may represent an evolutionarily conserved structural mechanism of transcription regulation

More than a meal… integrating non-feeding interactions into food webs

Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (<3) interaction types. The great diversity of non-trophic interactions observed in nature has been poorly addressed by ecologists and largely excluded from network theory. Herein, we propose a conceptual framework that organises this diversity into three main functional classes defined by how they modify specific parameters in a dynamic food web model. This approach provides a path forward for incorporating non-trophic interactions in traditional food web models and offers a new perspective on tackling ecological complexity that should stimulate both theoretical and empirical approaches to understanding the patterns and dynamics of diverse species interactions in nature.Keywords: Ecosystem engineering, Non-trophic interactions, Ecological network, Food web, Interaction modification, Facilitation, Trophic interaction

A united statement of the global chiropractic research community against the pseudoscientific claim that chiropractic care boosts immunity.

BACKGROUND: In the midst of the coronavirus pandemic, the International Chiropractors Association (ICA) posted reports claiming that chiropractic care can impact the immune system. These claims clash with recommendations from the World Health Organization and World Federation of Chiropractic. We discuss the scientific validity of the claims made in these ICA reports. MAIN BODY: We reviewed the two reports posted by the ICA on their website on March 20 and March 28, 2020. We explored the method used to develop the claim that chiropractic adjustments impact the immune system and discuss the scientific merit of that claim. We provide a response to the ICA reports and explain why this claim lacks scientific credibility and is dangerous to the public. More than 150 researchers from 11 countries reviewed and endorsed our response. CONCLUSION: In their reports, the ICA provided no valid clinical scientific evidence that chiropractic care can impact the immune system. We call on regulatory authorities and professional leaders to take robust political and regulatory action against those claiming that chiropractic adjustments have a clinical impact on the immune system

Collecting Sea Palms: Planning for Sustainable Use in a Variable Environment

Sea palm harvesting is a largely unregulated cottage industry centered along the rugged rocky coast of Sonoma County, California. The project's scientists tested different harvesting practices to identify those that were most sustainable, given the plant’s growth and reproductive cycles

Collecting Sea Palms: Planning for Sustainable Use in a Variable Environment

Up until recently, few in mainstream America ate seaweed, or wanted to. Edible seaweed was a concept relegated to, for all practical purposes, Asian and Native American cultures and cuisines. Times have changed. Today, bulk bins at health food stores overflow with kombu, nori, wakame, dulse and all sorts of other kinds of “sea vegetables,” while high- end vegetarian restaurants offer entrées as innovative (and unexpected) as seaweed strudel.The allure for health-conscious Americans is obvious: seaweeds are high in iodine, iron, phosphorous, potassium, manganese, copper and zinc, as well as vitamins A, B, C, E and K. They are low in calories, and low on the food chain. Although not technically plants, in most people’s minds, seaweed counts toward the “fruits and vegetables” part of the food pyramid

Collecting Sea Palms: Planning for Sustainable Use in a Variable Environment

Up until recently, few in mainstream America ate seaweed, or wanted to. Edible seaweed was a concept relegated to, for all practical purposes, Asian and Native American cultures and cuisines. Times have changed. Today, bulk bins at health food stores overflow with kombu, nori, wakame, dulse and all sorts of other kinds of “sea vegetables,” while high- end vegetarian restaurants offer entrées as innovative (and unexpected) as seaweed strudel.The allure for health-conscious Americans is obvious: seaweeds are high in iodine, iron, phosphorous, potassium, manganese, copper and zinc, as well as vitamins A, B, C, E and K. They are low in calories, and low on the food chain. Although not technically plants, in most people’s minds, seaweed counts toward the “fruits and vegetables” part of the food pyramid