-
Hankel Tournaments and Special Oriented Graphs
Richard Brualdi and Lei Cao
[Chapter Abstract]
A Hankel tournament T of order n (an n × n Hankel tournament matrix T = [tij]) is a tournament such that i → j an edge implies (n + 1 − j) → (n + 1 − i) is also an edge (tij = tn+1−j,n+1−i) for all i and j. Hankel tournament matrices are (0, 1)-matrices which are combinatorially antisymmetric about the main diagonal and symmetric about the Hankel diagonal (the antidiagonal). Locally transitive tournaments are tournaments such that the in-neighborhood and the out-neighborhood of each vertex are transitive. Tournaments form a special class of oriented graphs. The score vectors of Hankel tournaments and of locally transitive tournaments have been characterized where each score vector of a locally transitive tournament is also a score vector of a Hankel tournament. In this paper we continue investigations into Hankel tournaments and locally transitive tournaments. We investigate Hankel cycles in Hankel tournaments and show in particular that a strongly connected Hankel tournament contains a Hankel Hamilton cycle and, in fact, is Hankel “even-pancyclic” or Hankel “odd-pancyclic.” We show that a Hankel score vector can be achieved by a Hankel “half-transitive” tournament, extending the corresponding result for score vectors of tournaments. We also consider some results on oriented graphs and the question of attainability of prescribed degrees by oriented graphs. Finally, we extend some results on 2-tournaments to Hankel 2-tournaments. In some instances we rely on the reader to extend arguments already in the literature. We illustrate our investigations with many examples.
-
Chapter 8: Biophysical model of coral population connectivity in the Arabian/Persian Gulf
Geórgenes Cavalcante, Filipe Vieira, Jonas Mortensen, Radhouane Ben-Hamadou, Pedro Range, Elizabeth A. Goergen, Edmo Campos, and Bernhard M. Riegl
The coral reef ecosystems of the Arabian/Persian Gulf (the Gulf) are facing profound pressure from climate change (extreme temperatures) and anthropogenic (land-use and population-related) stressors. Increasing degradation at local and regional scales has already resulted in widespread coral cover reduction. Connectivity, the transport and exchange of larvae among geographically separated populations, plays an essential role in recovery and maintenance of biodiversity and resilience of coral reef populations. Here, an oceanographic model in 3-D high-resolution was used to simulate particle dispersion of “virtual larvae.” We investigated the potential physical connectivity of coral reefs among different regions in the Gulf. Simulations reveal that basin-scale circulation is responsible for broader spatial dispersion of the larvae in the central region of the Gulf, and tidally-driven currents characterized the more localized connectivity pattern in regions along the shores in the Gulf's southern part. Results suggest predominant self-recruitment of reefs with highest source and sink ratios along the Bahrain and western Qatar coasts, followed by the south eastern Qatar and continental Abu Dhabi coast. The central sector of the Gulf is suggested as recruitment source in a stepping-stone dynamics. Recruitment intensity declined moving away from the Straits of Hormuz. Connectivity varied in models assuming passive versus active mode of larvae movement. This suggests that larval behaviour needs to be taken into consideration when establishing dispersion models, and establishing conservation strategies for these vulnerable ecosystems.
-
Exploring the Benefits of Mindset and Literacy to Engage in Acts of Peace and Social Justice Education
Kelly A. Concannon and Monique Scoggin
Drawing from many disciplinary areas, this edited volume shares tools, techniques and ideas for engaging college students in difficult discussions. From sexual violence to race to poverty and more, chapters in the book present useful strategies as well as limitations in creating safe classroom spaces. Ideal for peace and justice educators, this volume also includes the voices of students in every chapter.
-
Impacts of the COVID-19 Pandemic on Global Education
Santanu De
Coronavirus Infectious Disease 2019 (COVID-19) has been one of the most dreaded, recent pandemics impacting multifarious global sectors, including education. To control contagion, affected nations ordered academic campus closures and home-schooling plans. Schools, colleges, and universities underwent a paradigm shift adopting internet-based delivery of lectures, synchronously or asynchronously (recorded), with virtual labs. Medical education suffered significantly; suspending student internships in hospitals decreased practical exposure to clinical specialties, impairing students’ performance, and competency.Teachers of traditional classes, with technical assistance, undertook rigorous trainings to restructure pedagogical and assessment strategies online using web/mobile applications and other digital tools.
-
In Pursuit of Harmony: How a Shared Leadership Practice Works as a Conflict Management System
Alexia Georgakopoulos and Barb Allen
Conflicts happen, and the workplace can be a cacophony for competing interests. Consider that organizational culture is an ensemble of shared values, beliefs, assumptions, perceptions, and norms. Organizations are not solos. They are an accompaniment of individuals, departments, and divisions, and each is competing for scarce resources. Measure in a little power imbalance and organizational political posturing. Then, scale in the fact that today’s managers are faced with diversity and cultural issues ranging from race and gender to individual ethnicity, principles, and philosophies, about which employees are more vocal. All this discord can strike a sharp note of dissonance. However, effective resolutions can change this discord to harmony.
Consider that music is not a single note. Rather, it is the silence between the notes that makes beautiful music, and conflict is that silence. Unfortunately, conflict has a bad reputation, and it is often labeled as disagreement, fighting, or arguing that leads to stress, retaliation, and resentment. Some managers spend a disproportionate amount of their workdays dealing with conflicts. They have not learned what causes conflicts or how to productively manage them. As a result, they often avoid or force outcomes causing discord, fractured relationships, loss of productivity, and even lawsuits. Learning to fine tune inevitable conflicts will help managers orchestrate a more harmonious workplace.
From Discord to Harmony: Making the Workplace Hum is largely evidence-based, and many of the chapters contain cutting-edge research by experts in their respective fields. -
Chapter 15: A tropical eastern Pacific invasive brittle star species (Echinodermata: Ophiuroidea) reaches southeastern Florida
Peter W. Glynn, Renata Alitto, Joshua Dominguez, Ana B. Christensen, Phillip Gillette, Nicolas Martinez, Bernhard M. Riegl, and Kyle Dettloff
The invasive brittle star Ophiothela mirabilis (family Ophiotrichidae), a tropical Indo-Pacific endemic species, first reported in Atlantic waters off southern Brazil in 2000, has extended its range northward to the Caribbean Sea, to the Lesser Antilles in 2011, and was first reported in south Florida in January 2019. Its occurrence in southeast Florida extends along nearly 70 km of coastline, from near the Port of Miami, Miami-Dade County, northward to Deerfield Beach, Broward County. It occurs abundantly as an epizoite on octocorals, attaining population densities of 25 individuals and more per 10-cm long octocoral stem. The surface texture of octocoral hosts (rough, smooth) did not affect the densities of the ophiuroid epizoites, and there were significantly greater abundances on octocorals during two winter sampling periods than in the summer. Beige and orange-coloured morphs are sometimes present on the same octocoral stem. Gut content analysis supported a suspension feeding mode, revealing essentially identical ingested items in both colour morphs with a preponderance of amorphous detritus and filamentous algae. Molecular genetic evidence (COI & 16s) has established the identity of O. mirabilis and its relationship to invasive Brazilian populations. The orange and beige morphs form two distinct, but closely related lineages that may represent two separate introductions. The orange morph shares haplotypes with Brazilian and Caribbean specimens suggesting a further range expansion of the ‘original’ invasion. The beige morph, however, shares haplotypes with specimens from the Mexican Pacific and Peru and potentially represents a secondary introduction. Traits promoting dispersal and establishment of this species in new habitats are manifold: vagility and ability to cling tightly to diverse host taxa (e.g. sponges, cnidarians, bryozoans, and echinoderms), frequent asexual reproduction (fissiparity), suspension feeding, including a wide range of dietary items, possession of integument-covered ossicles and arm spines offering protection from predators, and an effective competitive edge over associated microbiota for substrate space.
-
Chapter 4: Spatial and temporal differences in Acropora cervicornis colony size and health
Elizabeth A. Goergen, Kathleen Semon Lunz, and David S. Gilliam
Little to no recovery in Acropora cervicornis populations has been documented since the 1970s and 1980s widespread disease events, and disease and predation appear to remain significant drivers of mortality. However, to date, demographic studies of A. cervicornis lack data temporally or spatially sufficient to quantify factors limiting recovery. Acropora cervicornis populations in three regions [Broward County (BWD), Middle Keys (MDK), and Dry Tortugas (DRTO)] of the Florida Reef Tract were surveyed up to three times per year from 2011 to 2015. Temporal and spatial differences were evaluated for colony size, live tissue volume, and prevalence and impact of disease and predation. Significantly larger colonies were reported in BWD, and at relatively deeper or more sheltered sites. At least 43% of colonies in each region were of reproductively capable size. Mean relative change in colony size between surveys (3–5 months) ranged from − 20% to 19%. Disease and predation were consistently present in all regions, but levels varied significantly across space and time. Disease prevalence was the most variable condition (ranging from 0% to 28% per survey), increasing after periods of elevated temperatures and environmental disturbances, and caused significantly more partial mortality than fireworm (Hermodice carunculata) or snail (Coralliophila spp.) predation. Recovery potential and long-term persistence of this species may be limited due to the persistent presence of disease and predation, and reproductive limitations. However, there is still potential at sites of greater depth and/or more protection hosted larger and healthier colonies creating potential refugia for this species.
-
Race, Power, and the Law: Southern Legal and Constitutional History
Sally E. Hadden and Charles L. Zelden
A sweeping historiographical collection, Reinterpreting Southern Histories updates and expands upon the iconic volumes Writing Southern History and Interpreting Southern History, both published by Louisiana State University Press. With nineteen original essays cowritten by some of the most prominent historians working in southern history today, this volume boldly explores the current state, methods, innovations, and prospects of the richly diverse and transforming field of southern history.
Two scholars at different stages of their careers coauthor each essay, working collaboratively to provide broad knowledge of the most recent historiography and an expansive vision for historiographical contexts. This innovative approach provides an intellectual connection with the earlier volumes while reflecting cutting-edge scholarship in the field. Underlying each essay is the cultural turn of the 1980s and 1990s, which introduced the use of language and cultural symbols and the influence of gender studies, postcolonial studies, and memory studies. The essays also rely less on framing the South as a distinct region and more on contextualizing it within national and global conversations.
Reinterpreting Southern Histories, like the two classic volumes that preceded it, serves as both a comprehensive analysis of the current historiography of the South and a reinterpretation of that history, reaching new conclusions for enduring questions and establishing the parameters of future debates.
-
Advances in Computer Science for Engineering and Education II
Zhengbing Hu, Sergey Petoukhov, Ivan Dychka, and Matthew He
This book gathers high-quality, peer-reviewed research papers presented at the Second International Conference on Computer Science, Engineering and Education Applications (ICCSEEA2019), held in Kiev, Ukraine on 26–27 January 2019, and jointly organized by the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” and the International Research Association of Modern Education and Computer Science. The papers discuss state-of-the-art topics and advances in computer science; neural networks; pattern recognition; engineering techniques; genetic coding systems; deep learning and its medical applications; and knowledge representation and its applications in education. Given its scope, the book offers an excellent resource for researchers, engineers, management practitioners, and graduate and undergraduate students interested in computer science and its applications in engineering and education.
-
Advances in Artificial Systems for Medicine and Education II
Zhengbing Hu, Sergey Petoukhov, and Matthew He
This book includes the proceedings of the Second International Conference of Artificial Intelligence, Medical Engineering, Education (AIMEE2018), held in Moscow, Russia, on 6–8 October 2018. The conference covered advances in the development of artificial intelligence systems and their applications in various fields, from medicine and technology to education. The papers presented in the book discuss topics in mathematics and biomathematics; medical approaches; and technological and educational approaches. Given the rapid development of artificial intelligence systems, the book highlights the need for more intensive training for a growing number of specialists, particularly in medical engineering, to increase the effectiveness of medical diagnosis and treatment. The book is intended for specialists, students and other readers who would like to know where artificial intelligence systems can beneficially be applied in the future.
-
Advances in Artificial Systems for Medicine and Education III
Zhengbing Hu, Sergey Petoukhov, and Matthew He
This book discusses the latest advances in the development of artificial intelligence systems and their applications in various fields, from medicine and technology to education. It comprises papers presented at the Third International Conference of Artificial Intelligence, Medical Engineering, Education (AIMEE2019), held at the Mechanical Engineering Institute of the Russian Academy of Sciences, Moscow, Russia, on 1–3 October 2019. Covering topics such as mathematics and biomathematics; medical approaches; and technological and educational approaches, it is intended for the growing number of specialists and students in this field, as well as other readers interested in discovering where artificial intelligence systems can be applied in the future.
-
Advances in Intelligent Systems, Computer Science and Digital Economics
Zhengbing Hu, Sergey Petoukhov, and Matthew He
This book comprises high-quality, refereed research papers presented at the 2019 International Symposium on Computer Science, Digital Economy and Intelligent Systems (CSDEIS2019): The symposium, held in Moscow, Russia, on 4–6 October 2019, was organized jointly by Moscow State Technical University and the International Research Association of Modern Education and Computer Science. The book discusses the state of the art in areas such as computer science and its technological applications; intelligent systems and intellectual approaches; and digital economics and methodological approaches. It is an excellent reference resource for researchers, undergraduate and graduate students, engineers, and management practitioners interested in computer science and its applications in engineering and management.
-
Communication and Conflict Resolution Skills
Neil H. Katz, John W. Lawyer, Katherine Joanna Sosa, Marcia Sweedler, and Peter Tokar
In a new and significantly expanded third edition, Communication & Conflict Resolution Skills provides practical applications for enhancing communication and personal or professional leadership effectiveness. Engaging, user-friendly material will assist in building skills, improving relationships, and utilizing effective problem solving at work, at home, and in your communities. Instructors, students and trainers can use this book as a textbook, a handy “go-to” reference, or as a workbook to supplement workshops and learning experiences in communication and conflict management.
This book presents immediately applicable knowledge and skills in a series of small, understandable units that the reader can practice, master, and use as building blocks to enhance interpersonal and group success. Topics include:- Learning and Skill Development – understand the critical components and steps in acquiring the core conflict resolution competencies.
- Information Sharing — learn to identify personal outcomes in communication and the outcomes of others. Establish and maintain rapport, and use language effectively to ensure that the message is accurate and clear.
- Reflective Listening — develop the ability to clearly hear what another is communicating and understand what is being said at both the content and feeling level.
- Problem Solving — formulate accurate problem statements, clarify problems, and facilitate the problem solving of others. The skills of transferal and referral are also covered.
- Assertion — communicate thoughts, feelings, and concerns directly in a way that does not damage self-esteem or endanger the relationship.
- Conflict Resolution — develop skills of conflict awareness, styles recognition, diagnosis, and interest-based negotiation. Learn two processes and models for addressing conflicts of resources and/or values.
Abundant exercises, self-assessments, role-plays, and chapter objectives and summaries are included to promote understanding and skill development.
This third edition now incorporates current research articles and reference links in every chapter so the reader can go beyond the material presented in the text for a more global perspective on communication and conflict resolution skills.
In addition, it is packaged with access to the KHQ, a user-friendly, self-testing application available on the iTunes and Google Play store. It includes questions based on the content in the publication and gives students feedback and explanations on answers.
-
An Example for Other Small Nations to Follow”: John F. Kennedy, Ireland and Decolonization
David P. Kilroy
David P. Kilroy Remembered by many observers as the highlight of his 1963 state visit, in an emotional address before the joint houses of the Oireachtas, John F. Kennedy referred to Ireland as “the first of the small nations in the twentieth century to win its struggle for independence. ” Kennedy promoted the young republic as an example of postcolonial modernization for emerging states in Africa and Asia to emulate. Veteran Irish parliamentary reporter Brian Inglis noted that “hardened politicians wept in their seats” as Kennedy characterized Ireland’s leaders as men who knew “the meaning of foreign domination” and praised them for now providing a voice for other small nations on the world stage. Kennedy’s message resonated strongly with political leadership on both sides of the parliamentary aisle, most of whom were veterans of Ireland’s armed independence struggle between 1916 and 1921. Officials in the Irish Department of External Affairs...
Book Description
Using John F. Kennedy as a central figure and reference point, this volume explores how postcolonial citizens viewed the US president when peak decolonization met the Cold War. Exploring how their appropriations blended with their own domestic and regional realities, the chapters span sources, cases and languages from Latin America, Africa, Asia and Europe to explore the history of US and third world relations in a way that pushes beyond US-centric themes.
Examining a range of actors, Globalizing the U.S. Presidency studies various political, sociocultural and economic domestic and regional contexts during the Cold War era, and explores themes such as appropriation, antagonism and contestation within decolonisation. Attempting to both de-americanize and globalize John F. Kennedy and the US Presidency, the chapters examine how the perceptions of the president were fed by everyday experiences of national and international postcolonial lives. The many examples of worldwide interest in the US president at this time illustrate that this time was a historical turning point for the role of the US on the global stage. The hopes and fears of peaking decolonization, the resulting pressure on Washington, Moscow and other powers, and a new mediascape together ushered in a more comprehensive globalization of international politics, and a new meaning to 'the United States in the world'. -
Atlas of Mammalian Chromosomes
Stephen James O'Brien, Alexander S. Graphodatsky, and Polina L. Perelman
Filled with a visually exquisite collection of the banded metaphase chromosome karyotypes from some 1,000 species of mammals, the Atlas of Mammalian Chromosomes offers an unabridged compendium of the state of this genomic art form. The Atlas??contains the best karyotype produced, the common and Latin name of the species, the published citation, and identifies the contributing authors. Nearly all karyotypes are G-banded, revealing the chromosomal bar codes of homologous segments among related species. The Atlas brings together information from a range of cytogenetic literature and features high-quality karyotype images for nearly every mammal studied to date.
When the Atlas was first published, only three mammals were sequenced. Today, that number is over 300. Now in its second edition, this book contains extensive revisions and major additions such as new karyotypes that employ G- and C- banding to represent euchromatin and heterochromatin genome composition, new phylogenetic trees for each order, homology segment chromosome information on published aligned chromosome painting. Summaries of the painting data for some species indicate conserved homology segments among compared species. An invaluable resource for today's comparative genomics era, this comprehensive collection of high-resolution chromosome photographs:
- Assembles information previously scattered throughout the cytogenetics literature in one comprehensive volume
- Provides chromosome information and illustrations for the karyotypes of 300 new species
- Addresses the mandate of the Human Genome Project to annotate the genomes of other organisms
- Serves as a basis for chromosome-level genome assemblies
- Offers a detailed summation of three decades of ZooFish (chromosome painting)
- Presents high-resolution photos of karyotypes that represent more than 1,000 mammal species
Written for geneticists, mammalogists, and biologists, the Atlas of Mammalian Chromosomes offers a step forward for an understanding of species formation, of genome organization, and of DNA script for natural selection.
-
Chapter 2: Projected shifts in coral size structure in the Anthropocene
Chiara Pisapia, Peter J. Edmunds, Holly V. Moeller, Bernhard M. Riegl, Mike McWilliam, Christopher D. Wells, and Morgan S. Pratchett
Changes in the size structure of coral populations have major consequences for population dynamics and community function, yet many coral reef monitoring projects do not record this critical feature. Consequently, our understanding of current and future trajectories in coral size structure, and the demographic processes underlying these changes, is still emerging. Here, we provide a conceptual summary of the benefits to be gained from more comprehensive attention to the size of coral colonies in reef monitoring projects, and we support our argument through the use of case-history examples and a simplified ecological model. We neither seek to review the available empirical data, or to rigorously explore causes and implications of changes in coral size, we seek to reveal the advantages to modifying ongoing programs to embrace the information inherent in changing coral colony size. Within this framework, we evaluate and forecast the mechanics and implications of changes in the population structure of corals that are transitioning from high to low abundance, and from large to small colonies, sometimes without striking effects on planar coral cover. Using two coral reef locations that have been sampled for coral size, we use demographic data to underscore the limitations of coral cover in understanding the causes and consequences of long-term declining coral size, and abundance. A stage-structured matrix model is used to evaluate the demographic causes of declining coral colony size and abundance, particularly with respect to the risks of extinction. The model revealed differential effects of mortality, growth and fecundity on coral size distributions. It also suggested that colony rarity and declining colony size in association with partial tissue mortality and chronic declines in fecundity, can lead to a demographic bottleneck with the potential to prolong the existence of coral populations when they are characterized by mostly very small colonies. Such bottlenecks could have ecological importance if they can delay extinction and provide time for human intervention to alleviate the environmental degradation driving reductions in coral abundance.
-
Chapter 1: Population dynamics of the reef crisis: Consequences of the growing human population
Bernhard M. Riegl and Peter W. Glynn
An unequivocal link exists between human population density and environmental degradation, both in the near field (local impacts) and far field (impacts due to teleconnections). Human population is most widely predicted to reach 9–11 billion by 2100, when the demographic transition is expected in all but a handful of countries. Strongest population growth is in the tropics, where coral reefs face dense human population and concomitant heavy usage. In most countries, > 50% will be urbanized but growth of rural population and need for food in urban centres will not alleviate pressure on reef resources. Aquaculture will alleviate some fishing pressure, but still utilizes reef surface and is also destructive. Denser coastal populations and greater wealth will lead to reef degradation by coastal construction. Denser populations inland will lead to more runoff and siltation. Effects of human perturbations can be explored with metapopulation theory since they translate to increases in patch-mortality and decreases in patch-colonization (= regeneration). All such changes will result in a habitat with overall fewer settled patches, so fewer live reefs. If rescue effects are included, bifurcations in system dynamics will allow for many empty patches and, depending on system state relative to stable and unstable equilibria, a part-empty system may either trend towards stability at higher patch occupancy or extinction. Thus, unless the disturbance history is known, it may be difficult to assess the direction of system trajectory—making management difficult. If habitat is decreased by destruction, rescue effects become even more important as extinction-debt, accumulated by efficient competitors with weaker dispersal ability, is realized. Easily visible trends in human population dynamics combined with well-established and tested ecological theory give a clear, intuitive, yet quantifiable guide to the severity of survival challenges faced by coral reefs. Management challenges and required actions can be clearly shown and, contrary to frequent claims, no scientific ambiguity exists with regards to the serious threat posed to coral reefs by humankind's continued numerical increase.
-
Born in Chanel, Christen in Gucci: The Rhetoric of Brand Names and Haute Couture in Jamaican Dancehall
Andrea E. Shaw-Nevins
Dancehall: A Reader on Jamaican Music and Culture contextualizes the emergence of the globally popular dancehall genre, while tracing the complex and often contradictory aspects of its evolution, dispersion and politics. This collection of foundational essays places dancehall in context with cutting-edge analyses of performance modes and expression, genre development, and impact in the wider local, regional and international socio-political milieu of struggles by black Jamaicans in particular and cultural adherents more broadly.
Dancehall is one of eight musical genres created in Jamaica and, in the past two decades, it has become one of the most influential Jamaican cultural exports since reggae. The impact of dancehall extends far beyond Jamaica and is evident in music genres (such as hip hop, trip hop, jungle, reggaeton, South African kwaito and Nigerian Afrobeats) and international fashion, film and dance.
This interdisciplinary volume documents various aspects of dancehall’s global impact, evolution and influence in gender, political economy, geography, ethnomusicology, spirituality, music production, fashion and language. Each selection interrogates the range of meanings ascribed to dancehall culture, a phenomenon which has been seen to be associated with violence, crime and debauchery. This collection exposes the immense cultural work towards self-expression and identity in post-colonial Jamaica which takes shape through dancehall and the contributors apply a new level of seriousness, depth and academic rigour to dancehall studies.
-
The Scientific Explorations for Deep-Sea Fishes in Brazil: The Known Knowns, the Known Unknowns, and the Unknown Unknowns
Marcelo Roberto Souto de Melo, Rodridgo Antunes Caires, and Tracey Sutton
The deep sea is the largest and one of the most extreme environments on Earth. It is estimated that 10–15% of all fish species are dwelling in the deep sea, most of which have unique morphological and physiological adaptations. Biological expeditions to sample the deep ocean off Brazil started with the British HMS Challenger Expedition (1872–1876), followed by a few fishery stations made by the German RV Ernst Haeckel (1966) and the North-American MIV Oregon II (1957–1975), the cruises of the French RVs Marion Dufresne (1987) and Thalassa (1999, 2000), the Brazilian RV Atlântico Sul (1996–1999), the FV Diadorim and FV Soloncy Moura (1996–2002), OSB Astro Garoupa (2003), and, more recently, the American RV Luke Thomas and Seward Johnson (2009, 2011), the French RV Antea (2015, 2017), and the Brazilian RV Alpha Crucis. A total of 712 species of deep-sea fishes were recorded, including five species of Myxini, six species of Holocephali, 81 species of Elasmobrachii, and 620 species of Actinopteri. As in other parts of the world, the Brazilian deep-sea ichthyofauna struggles under severe anthropogenic impacts caused by the commercial fishing, and the extraction of oil and gas. The deep ocean is a delicate environment and its recovery is considerably slower than an equivalent in shallow water habitat. Therefore, increasing the research efforts is needed to avoid that part of its diversity disappear without our accurate knowledge.
-
Chapter 14: Octocoral populations and connectivity in continental Ecuador and Galápagos, Eastern Pacific
Sascha C.C. Steiner, Priscilla Martínez, Fernando Rivera, Matthew Johnston, and Bernhard M. Riegl
Octocorals are important zoobenthic organisms, contributing to structural heterogeneity and species diversity on hardgrounds. Their persistence amidst global coral reef degradation and ocean acidification, has prompted renewed interest in this taxon. Octocoral assemblages at 52 sites in continental Ecuador and Galápagos (23 species, 3742 colonies) were examined for composition, size distributions within and among populations, and connectivity patterns based on ocean current models. Species richness varied from 1 to 14 species per site, with the richest sites on the continent. Three assemblage clusters were recognised based on species richness and population size, one with a mix of sites from the mainland and Galápagos (defined by Muricea fruticosa and Leptogorgia alba, Muricea plantaginea and Pacifigorgia darwinii), the second from Santa Elena in southern Ecuador (defined by M. plantaginea and L. alba) and the third from the northernmost sites on the continent, in Esmeraldas (defined by Muricea fruticosa, Heterogorgia hickmani, Leptogorgia manabiensis). Based on biophysical larval flow models with 30, 60, 90-day Pelagic Larval Duration, good connectivity existed along the South American mainland, and from the continent to Galápagos. Connectivity between Galápagos, Cocos, Malpelo and the Colombian mainland may explain the wide distribution of L. alba. Muricea plantaginea had the densest populations with the largest colonies and therewith was an important habitat provider both in continental Ecuador and Galápagos. Continental Ecuador harbours the most speciose populations of octocorals so far recorded in the southern Eastern Tropical Pacific (ETP). Most species were uncommon and possibly vulnerable to local extirpation. The present study may serve as a base line to determine local and regional impacts of future disturbances on ETP octocorals.
-
As Gulf Oil Extraction Goes Deeper, Who Is at Risk? Community Structure, Distribution, and Connectivity of the Deep-Pelagic Fauna
Tracey Sutton, Tamara Frank Dr., Heather Judkins, and I. C. Romero
The habitat and biota most affected by ultra-deep oil spills in the Gulf of Mexico (GoM) will necessarily be in the deep-pelagic domain. This domain represents ~91% of the GoM’s volume and almost certainly contains the majority of its metazoan inhabitants. Ultra-deep oil spills may or may not reach the surface or the seafloor but will occur entirely within the deepwater column domain at some point and likely for the longest duration. Recent research has shown the deep-pelagic GoM to be extremely rich in biodiversity, both taxonomic and functional. Indeed, the GoM is one of the four “hyperdiverse” midwater ecosystems in the World Ocean. This biodiversity is functionally important. For example, well over half (58%) of all fish species known to exist in the GoM spend all or part of their lives in the oceanic domain. Recent research has also shown the deep-pelagic GoM to be highly connected vertically, as well as horizontally (onshore-offshore). This vertical connectivity provides an increasingly valued ecosystem service in the form of atmospheric carbon sequestration via the “biological pump.” In this chapter, we summarize the GoM deep-pelagic nekton (fishes, macrocrustaceans, and cephalopods) that have been, and would be, affected by ultra-deep oil spills. We also discuss key aspects of distribution and behavior (e.g., vertical migration). These behaviors and distributions are key elements of ecosystem assessments before and after oil spills. For example, some deep-pelagic taxa show affinities for oceanic rim habitats (i.e., continental slopes), where ultra-deep drilling is most intense. Lastly, we summarize what is known about hydrocarbon contamination in the deep-pelagic biota and its possible ecosystem consequences.
-
Mesopelagic Ocean Waters
Kate E. Watermeyer, Eduard J. Gregr, Ryan R. Rykaczewski, Imants G. Priede, Tracey Sutton, and David A. Keith
-
Epipelagic Ocean Waters
Kate E. Watermeyer, Ryan R. Rykaczewski, Imants G. Priede, Tracey Sutton, and David A. Keith
Printing is not supported at the primary Gallery Thumbnail page. Please first navigate to a specific Image before printing.
