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Tracing Water Masses With 129i And 236u In The Subpolar North Atlantic Along The Geotraces Ga01 Section, Maxi Castrillijo, Núria Casacuberta, Marcus Christl, Christoph Vockenhuber, Hans A. Synall, Maribel I. García-Ibáñez, Pascale Lherminier, Géraldine Sarthou, Jordi García-Orellana, Pere Masqué

Research outputs 2014 to 2021

Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide complementary information to improve the current understanding of the circulation in the SPNA. To this end, we present the first simultaneous distribution of artificial 129I and 236U in 14 depth profiles and in surface waters along the GEOVIDE section covering a zonal transect through the SPNA in spring 2014. Our results show that the two tracers …

The Value Of Animal Behaviour As A Bio-Indicator Of Restoration Quality, Floyd Holmes

Theses: Doctorates and Masters

Woodland restoration is a complex endeavour, and restoration ecology as a scientific discipline requires constant re-assessments and adjustments if it is to improve outcomes and better provide for biodiversity. The promise of effective restoration is often used to justify destructive processes that affect many of the world’s ecosystems. It is therefore imperative that those promises can be met, which comes down to restoration ecologists’ and land managers’ capacity to predict and facilitate desirable ecological changes in a timely and socio-economically responsible manner. As perspectives have changed, and knowledge has been gained over the past few decades there have been several …

Expanding Greenland Seagrass Meadows Contribute New Sediment Carbon Sinks, Núria Marbà, Dorte Krause-Jensen, Pere Masque´, Carlos M. Duarte

Research outputs 2014 to 2021

The loss of natural carbon sinks, such as seagrass meadows, contributes to grenhouse gas emissions and, thus, global warming. Whereas seagrass meadows are declining in temperate and tropical regions, they are expected to expand into the Arctic with future warming. Using paleoreconstruction of carbon burial and sources of organic carbon to shallow coastal sediments of three Greenland seagrass (Zostera marina) meadows of contrasting density and age, we test the hypothesis that Arctic seagrass meadows are expanding along with the associated sediment carbon sinks. We show that sediments accreted before 1900 were highly 13C depleted, indicative of low inputs of seagrass …

A Review Of Heat Stress Policies In The Context Of Climate Change And Its Impacts On Outdoor Workers: Evidence From Zimbabwe, Bigboy Ngwenya, Jacques Oosthuizen, Martyn Cross, Kwasi Frimpong, Cynthia N. Chaibva

Research outputs 2014 to 2021

Record-breaking summer heat events are increasing in frequency in Zimbabwe and 2016 was a particularly hot year with the country experiencing its worst heat wave event in decades. Currently, Zimbabwe has no coordinated public health response to deal with heat wave events and no specific data on heat-related morbidity and mortality. The country has no legislation for protecting workers against environmental heat exposure, particularly those most vulnerable who are employed in the informal sector. These workers are also at risk due to their outdoor work environments. The article outlines the state of climate and heat stresses in Zimbabwe, as benchmarked …

Evaluating Current And Future Range Limits Of An Endangered, Keystone Rodent (Dipodomys Ingens), Ivy V. Widick

Cal Poly Humboldt theses and projects

Climate is often considered the single most important factor limiting species’ ranges. Other factors, such as biotic interactions, are often assumed to be included via abiotic proxies. However, differential responses to climate change may decouple these relationships or lead to adaptation to novel environments. Accounting for competition and local adaptation should more accurately describe environmental factors influencing current distributions and increase the predictive accuracy of future distributions. Modeling the endangered giant kangaroo rat (Dipodomys ingens) is an excellent application of these model improvements, as the species range consists of geographically and genetically isolated populations experiencing disparate climatic change. …

The Effects Of Forest Degradation On Dna Methylation In Central African Songbirds, Andrew K. Wiegardt

Cal Poly Humboldt theses and projects

Environmentally-induced stress can initiate a molecular response through DNA methylation, which can alter gene expression, thereby serving as a mechanism allowing individuals to acclimate to a changing environment within their lifetime. In addition to DNA methylation, the production and release of corticosterone is a physiological mechanism by which birds can cope with acute environmental stressors. To assess how environmental stress impacted DNA methylation and corticosterone, I collected blood and feather samples from three understory avian species (Alethe castanea, Bleda notatus and Pseudalethe poliocephala), along a disturbance gradient in the lowland Guinean rainforest adjacent to the village of …

A Comparison Of Community Structure In Regulated And Unregulated Reaches In The Upper Eel River, California, Lara Stephanie Jansen

Cal Poly Humboldt theses and projects

Flow regulation of rivers by impoundments and diversions can reduce hydrological variability. As a result, densities of algae and benthic macroinvertebrates often increase, but many sensitive taxa are lost, causing shifts across the food web. In Northern California, dams that reduce winter peak floods can result in the primary consumer community becoming dominated by grazers that are relatively invulnerable to predation, which can reduce the amount of energy transferred up the trophic levels. The steeper slope of the spring hydrograph recession limb downstream of a dam can also greatly impact instream diversity of periphyton, invertebrates and fish. The dam and …

Effects Of Manual And Mechanical Ammophila Arenaria Removal Techniques On Coastal Dune Plant Communities And Dune Morphology, Monique R. Silva Crossman

Cal Poly Humboldt theses and projects

The removal of invasive species as part of the restoration process can allow natives organisms to rebound. An ecosystem that incurs damages from invasive species is coastal sand dunes, which are dynamic systems. Some coastal sand dunes on the west coast of the United States have been invaded by Ammophila arenaria. The invasive grass, A. arenaria, is thought to alter and stabilize foredune morphology and reduce populations of native species. The objectives of my research are to examine the effects that manual and mechanical A. arenaria removal techniques have on coastal sand dune morphology and vegetative cover over time. …

Jeweled Spider Flies (Eulonchus Tristis) Are Important Pollinators Of Iris Bracteata, A Rare Siskiyou Mountain Endemic, Jean-Paul E. Ponte

Cal Poly Humboldt theses and projects

Little is known about the pollination biology of the Pacific Coast Irises (Iris: series Californicae, hereafter PCI), especially who visits and pollinates their flowers. In general, Iris flowers are considered bee-pollinated, however, flies in the genus Eulonchus (Acroceridae) are known to visit some PCI members. Therefore, I assessed the relative importance of Eulonchus and other insect visitors to the pollination of a rare PCI species native to the Siskiyou Mountains, I. bracteata.

Methods. I quantified pollinator importance for all flower visitors at sites in northern California and southern Oregon as the product of average visit rate and …

First Stewards: Ecological Outcomes Of Forest And Wildlife Stewardship By Indigenous Peoples Of Wisconsin, Usa, Donald M. Waller, Nicholas J. Reo

Dartmouth Scholarship

Indigenous peoples manage forestlands and wildlife differently than public and private forestland managers. To evaluate ecological outcomes from these differences, we compared the structure, composition, and diversity of Ojibwe and Menominee tribal forests to nearby nontribal forestlands in northern Wisconsin. These indigenous peoples seek to manage forests for mature conditions, accommodate wolves and other predators, and hunt deer to sustain traditional livelihood values. Their forests are often more mature with higher tree volume, higher rates of tree regeneration, more plant diversity, and fewer invasive species than nearby nontribal forestlands. In contrast, nontribal forestlands lost appreciable plant diversity in the 20th …

Omnivore Density Affects Community Structure Through Multiple Trophic Cascades, Donald J. Benkendorf

Murray State Theses and Dissertations

Omnivores can dampen trophic cascades by feeding at multiple trophic levels, yet few studies have evaluated how intraspecific variation influences the effect of omnivores on community structure. The Speckled Dace (Rhinichthys osculus) is an omnivorous cyprinid that consumes algae and invertebrates and is abundant throughout the western United States. I sought to identify the effects of size and size structure on top-down control by dace and learn how these effects scaled with density. Dace were manipulated in a mesocosm experiment and resulting changes in invertebrate and algal communities and measures of ecosystem function were monitored. Omnivores affected experimental …

Trophic Interactions And Niche Partitioning Within A Post-White-Nose Syndrome Temperate Bat Community, Macy Kailing

Murray State Theses and Dissertations

The decline of cave-dwelling bats since the introduction of white-nose syndrome (WNS) to North America changed the way communities interact. Disease-mediated competition at the community level can influence the ability of imperiled species to recover because of competitive exclusion. In western Kentucky, tri-colored bats, Perimyotis subflavus, which are susceptible to WNS severely declined following WNS occurrence. During that same period, evening bats, Nycticeius humeralis, which are not susceptible to WNS increased markedly. To investigate the influence of WNS on community structure, the diets of sympatric tri-colored and evening bats were assessed. Guano was collected from evening (n=37) and …

Predator Presence And Size Variation Alters Community Structure Through Multiple Trophic Cascades, Robin Baker, Howard Whiteman Ph.D.

Murray State Theses and Dissertations

Predation plays a crucial role in shaping community structure and can initiate trophic cascades that can alter abundances across adjacent trophic levels. Recent research has suggested that variation among individual predators may have stronger effects on ecological dynamics than previously appreciated. Intraspecific variation within predators could lead to differential levels of top-down control with implications for trophic cascade strength. In this experiment, we manipulated the body size variation of predatory mole salamanders (Ambystoma talpoideum) within experimental mesocosms and monitored a suite of abiotic and biotic response variables. We predicted that predator populations with increased body size variation would …

Within-Fire Patchiness Associated With Prescribed Burning In The Northern Jarrah Forests Of Western Australia, Zigourney Nielsen

Theses: Doctorates and Masters

There is growing understanding of the importance of landscape mosaics and heterogeneity for biodiversity outcomes in Western Australia. However, there is limited information on the patchiness (spatial configuration of unburnt and burnt patches which occur at a range of spatial scales) within the perimeter of a single prescribed burn. Of particular concern is the idea that prescribed burning operations, carried out under very restricted weather and environmental conditions, can lead to structural and floristic homogenization of the area within a burn perimeter. This may be evident as reduced post-fire vegetation patchiness. Western Australian Jarrah (Eucalyptus marginata) forests are managed to …

Why Do We Want To Think Humans Are Different?, Colin A. Chapman, Michael A. Huffman

Animal Sentience

One harmful consequence of creating categories where one group is unique and superior to others is that it justifies committing negative, often atrocious, acts on the members of the inferior group. Correcting divisive human categorizations (racial superiority, gender superiority) has bettered society. Scholars have often claimed that humans are unique and superior to nonhuman animals. These claims need to be reevaluated. Many have already been refuted. Animals have been shown to outperform humans in many tasks, including cognitive ones. Here we raise the question: Has the false sense of superiority been used to justify human cruelty to animals?

Good News: Humans Are Neither Distinct Nor Superior, Anne Benvenuti

Animal Sentience

Chapman & Huffman suggest that to correct our thinking about the supposed superiority of humans over other animals, we must train our reasoned investigation upon ourselves. Their thesis may usefully be viewed from within the general findings of the cognitive revolution in science, particularly findings that speak to the limits of rationality in everyday thought of humans. That we have failed — throughout a long history of scientific and philosophical thought — to ask fundamental questions about animal cognition and emotion is rooted in the fact that much of our thinking, feeling, and behaving is beyond our own immediate grasp. …

Using Anthropocentrism To The Benefit Of Other Species, Vanessa Wilson

Animal Sentience

Chapman & Huffman (2018) argue that we should not consider humans as unique or superior to other animals when we have the chance to explore the diversity of the traits of other species. This is a valid and progressive point in our approach to research, but I suggest that an anthropocentric approach can have animal welfare benefits when it helps us perceive other species – especially distantly related ones such as crustaceans – in a human light.

Why Humans Are Different, Tara Fox Hall

Animal Sentience

A central human problem is our inference from the fact that we are the world’s most intelligent species to the alleged fact that we are superior. This inference is not mandatory. Successfully combating this inference may require the threat of a large-scale catastrophe to our species.

How To Foster Respect For Animals? Superiority, Dissimilarity, And Prejudice, Matteo Colombo

Animal Sentience

Chapman & Huffman (C & H) might be taken to argue as follows: Humans may treat animals however they want only if humans are superior to animals. But humans are not superior to animals. Therefore, humans may not treat animals however they want. Whatever its merit, this is not C & H’s actual argument. Their point, instead, is that humans often mistreat animals because they tend to perceive them as inferior. A remedy for animal mistreatment would then be acknowledging the deep similarities between us and animals. But is C & H’s suggested remedy likely to be effective to foster …

Insulting Words: "They Are Animals!", Carolyn A. Ristau

Animal Sentience

As Chapman & Huffman state, creating divisive human categories has rationalized atrocities committed against the “other.” Labeling neighboring warring villagers as “animals” is considered a despicable insult. Yet contemporary scientific views of many animals grant them thinking and conscious faculties, and the capacity for impressive achievements, many unattainable by humans. Robots, too, can accomplish many similar feats. But the essential reason we must protect animals is not because of their admirable abilities, but their capacity for consciousness, for suffering. Robots are not conscious. Participants in the human-animal debate should not complain about changing criteria for determining human uniqueness. New and …

Can They Suffer?, Todd K. Shackelford

Animal Sentience

We should treat sentient nonhuman animals as worthy of moral consideration, not because we share an evolutionary history with them, but because they can suffer. As Chapman & Huffman (2018) argue, humans are not uniquely disconnected from other species. We should minimize the suffering we inflict on sentient beings — whether human or nonhuman — not because they, too, are tool-makers or have sophisticated communication systems, but because they, too, can suffer, and suffering is bad.

We Don’T Want To Know What We Know, Judith Benz-Schwarzburg

Animal Sentience

Why are humans so ignorant with regard to the fundamental gap between ethical claims and the status quo of the human-animal relationship? To answer this, we should include more psychological and sociological perspectives in our discussions.

Two Fallacies In Comparisons Between Humans And Non-Humans, Don Ross

Animal Sentience

The hypothesis that humans are superior to non-humans by virtue of higher cognitive powers is often supported by two recurrent fallacies: (1) that any competence shown by humans but not by our closest living relatives (apes) must be unique to humans; and (2) that grades of intelligence can be inferred from behavior without regard to motivational structures.

What Sets Us Apart Could Be Our Salvation, Anne Fawcett, Paul Mcgreevy

Animal Sentience

We agree with Chapman & Huffman that human capacities are often assumed to be unique — or attempts are made to demonstrate uniqueness scientifically — in order to justify the exploitation of animals and ecosystems. To extend the argument that human exceptionalism is against our interests, we recommend adopting the One Welfare framework, according to which animal welfare, environmental sustainability and human wellbeing are inseparably linked. Let us distinguish ourselves from other animals by resisting our short- and mid-term Darwinian inclinations, consuming less, reproducing less, and striving for a much longer-term biological fitness for us all.

Fish Sentience Denial: Muddying The Waters, Lynne U. Sneddon, Javier Lopez-Luna, David C.C. Wolfenden, Matthew C. Leach, Ana M. Valentim, Peter J. Steenbergen, Nabila Bardine, Amanda D. Currie, Donald M. Broom, Culum Brown

Animal Sentience

Recent empirical studies have reported evidence that many aquatic species, including fish, cephalopods and crustaceans, have the capacity for nociception and pain, and that their welfare should be taken into consideration. Some sceptics, rejecting the precautionary principle, have denied that any study demonstrates pain or other aspects of sentience in fish. This target article discusses some of the scientific shortcomings of these critiques through a detailed analysis of a study exploring nociception and analgesia in larval zebrafish.

Fish Sentience, Consciousness, And Ai, Ila France Porcher

Animal Sentience

The systematic criticism of articles providing evidence that fish and invertebrates can feel pain is discussed. Beliefs are known to be stronger than evidence in the human mind, and could generate this outcry, while from another perspective, the criticisms appear as a territorial move by fishermen against a perceived threat to their domain. The scientific inconsistency in which consciousness is granted to machines but not to fish and invertebrates, purely due to political bias, is pointed out. No basis exists for denying sentience to any life form as long as science is ignorant of the nature and source of consciousness.

Fish Sentience Denial: Muddy Moral Water, Robert C. Jones

Animal Sentience

Sneddon et al. (2018) authoritatively summarize the compelling and overwhelming evidence for fish sentience, while methodically dismantling one rather emblematic research paper (Diggles et al. 2017) intended to discount solid evidence of fish sentience (Lopez-Luna et al. 2017a, 2017b, 2017c, & 2017d). I explore the larger practical moral contexts within which these debates take place and argue that denials of animal sentience are really moral canards.

Fish And Plant Sentience: Anesthetized Plants And Fishes Cannot Respond To Stimuli, Ken Yokawa, František Baluška

Animal Sentience

Recent denial of fish sentience is at variance with the fact that all living organisms need environmental awareness in order to survive in a continuously fluctuating environment. Moreover, fish sentience – like plant sentience – is also strongly supported by the sensitivity of fishes and plants to diverse anesthetics.

Defining Denial And Sentient Seafood, Jennifer Jacquet

Animal Sentience

Sneddon et al. address the scientists who reject the empirical evidence on fish sentience, calling them “sceptics” and their work “denial”. This is the first article to frame the question of fish sentience in these terms, and it provides an obvious opening for social science and humanities research in the science of fish sentience. It is also worth asking what practical changes in the lives of fish might arise from the mounting evidence of their sentience. I suggest that the relationship between sentience and our sense of moral obligation is not as clear as we often assume.

Sentience: All Or None Or Matter Of Degree?, Loren Martin, Robert Gerlai

Animal Sentience

The question of whether fish feel pain is muddied by anthropomorphic thinking. Comparing biological phenomena in two species should be informed by the criteria for good animal models: face validity, construct validity and predictive validity. Viewed through this lens, we argue that fish do feel pain and may possess some level of sentience. Evolutionary relatedness, hence similarities and differences between species (fish and humans in this case), are not about black vs. white but about shades of grey.