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Constantine Alexander
Where Nature runs Wild!
I love not Man the less, but Nature more.
Recent Activity
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This is a live leatherback turtle entangled in fishing ropes which increases drag, Grenada 2014. Credit: Kate Charles, Ocean Spirits. Hundreds of marine turtles die every year after becoming entangled in rubbish in the oceans and on beaches, including plastic 'six pack' holders and disgarded fishing gear. The rise in... Continue reading
Posted 13 hours ago at Constantine Alexander's Journal
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Hundreds of millions of cubic meters of vital seagrass meadows worldwide can potentially be at risk of collapse from accumulated effects of repeated dredging and natural stress. QUT Research Fellow Dr. Paul Wu is part of a research team working towards saving seagrass from dredging. Photo by Anthony Weate/QUT Marketing... Continue reading
Posted 7 days ago at Constantine Alexander's Journal
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Example of an animal with nearly no sloughing skin (i.e., proportion of body with sloughing skin = <33%) (A) and another bowhead whale with a high degree of sloughing (>66% of body) and a blotchy skin type (B). Credit: Fortune et al (2017) CC BY Bowhead whales molt and rub... Continue reading
Posted Nov 24, 2017 at Constantine Alexander's Journal
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Species of the scyphozoan family Pelagiidae (e.g., Pelagia noctiluca, Chrysaora quinquecirrha) are well-known for impacting fisheries, aquaculture, and tourism, especially for the painful sting they can inflict on swimmers. However, historical taxonomic uncertainty at the genus (e.g., new genus Mawia) and species levels hinders progress in studying their biology and evolutionary adaptations that make them nuisance species, as well as ability to understand and/or mitigate their ecological and economic impacts. Continue reading
Posted Nov 24, 2017 at Constantine Alexander's Journal
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Lateralized behaviors benefit individuals by increasing task efficiency in foraging and anti-predator behaviors [1, 2, 3, 4]. The conventional lateralization paradigm suggests individuals are left or right lateralized, although the direction of this laterality can vary for different tasks (e.g. foraging or predator inspection/avoidance). By fitting tri-axial movement sensors to blue whales (Balaenoptera musculus), and by recording the direction and size of their rolls during lunge feeding events, we show how these animals differ from such a paradigm. The strength and direction of individuals’ lateralization were related to where and how the whales were feeding in the water column. Smaller rolls (≤180°) predominantly occurred at depth (>70 m), with whales being more likely to rotate clockwise around their longest axis (right lateralized). Larger rolls (>180°), conversely, occurred more often at shallower depths (<70 m) and were more likely to be performed anti-clockwise (left lateralized). More acrobatic rolls are typically used to target small, less dense krill patches near the water’s surface [5, 6], and we posit that the specialization of lateralized feeding strategies may enhance foraging efficiency in environments with heterogeneous prey distributions. Continue reading
Posted Nov 24, 2017 at Constantine Alexander's Journal
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Indigenous fisher spearfishing in Indonesia. Credit: Swansea University. Writing in the Journal Fish & Fisheries, Dr Richard Unsworth of Swansea University (together with colleagues at Cardiff University and Stockholm University) examine the global extent to which these meadows of underwater plants support fishing activity. "Wherever seagrass exists in proximity to... Continue reading
Posted Nov 24, 2017 at Constantine Alexander's Journal
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The increase in anthropogenic CO2 emissions over the last century has modified oceanic conditions, affecting marine ecosystems and the goods and services that they provide to society. Pacific Island countries and territories are highly vulnerable to these changes because of their strong dependence on ocean resources, high level of exposure to climate effects, and low adaptive capacity. Projections of mid-to-late 21st century changes in sea surface temperature (SST), dissolved oxygen, pH, and net primary productivity (NPP) were synthesized across the tropical Western Pacific under strong climate mitigation and business-as-usual scenarios. These projections were used to model impacts on marine biodiversity and potential fisheries catches. Results were consistent across three climate models, indicating that SST will rise by ≥ 3 °C, surface dissolved oxygen will decline by ≥ 0.01 ml L−1, pH will drop by ≥ 0.3, and NPP will decrease by 0.5 g m−2 d−1 across much of the region by 2100 under the business-as-usual scenario. These changes were associated with rates of local species extinction of > 50% in many regions as fishes and invertebrates decreased in abundance or migrated to regions with conditions more suitable to their bio-climate envelope. Maximum potential catch (MCP) was projected to decrease by > 50% across many areas, with the largest impacts in the western Pacific warm pool. Climate change scenarios that included strong mitigation resulted in substantial reductions of MCP losses, with the area where MCP losses exceeded 50% reduced from 74.4% of the region under business-as-usual to 36.0% of the region under the strong mitigation scenario. Continue reading
Posted Nov 16, 2017 at Constantine Alexander's Journal
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The Great Barrier Reef Marine Park (GBRMP) is the largest network of marine reserves in the world, yet little is known of the efficacy of no-fishing zones in the relatively lightly-exploited remote parts of the system (i.e., northern regions). Here, we find that the detection of reserve effects is challenging and that heterogeneity in benthic habitat composition, specifically branching coral cover, is one of the strongest driving forces of fish assemblages. As expected, the biomass of targeted fish species was generally greater (up to 5-fold) in no-take zones than in fished zones, but we found no differences between the two forms of no-take zone: ‘no-take’ versus ‘no-entry’. Strong effects of zoning were detected in the remote Far-North inshore reefs and more central outer reefs, but surprisingly fishing effects were absent in the less remote southern locations. Moreover, the biomass of highly targeted species was nearly 2-fold greater in fished areas of the Far-North than in any reserve (no-take or no-entry) further south. Despite high spatial variability in fish biomass, our results suggest that fishing pressure is greater in southern areas and that poaching within reserves may be common. Our results also suggest that fishers ‘fish the line’ as stock sizes in exploited areas decreased near larger no-take zones. Interestingly, an analysis of zoning effects on small, non-targeted fishes appeared to suggest a top-down effect from mesopredators, but was instead explained by variability in benthic composition. Thus, we demonstrate the importance of including appropriate covariates when testing for evidence of trophic cascades and reserve successes or failures. Continue reading
Posted Nov 12, 2017 at Constantine Alexander's Journal
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Human activities have placed populations of many endangered species at risk and mitigation efforts typically focus on reducing anthropogenic sources of mortality. However, failing to recognize the additional role of environmental factors in regulating birth and mortality rates can lead to erroneous demographic analyses and conclusions. The North Atlantic right whale population is currently the focus of conservation efforts aimed at reducing mortality rates associated with ship strikes and entanglement in fishing gear. Consistent monitoring of the population since 1980 has revealed evidence that climate-associated changes in prey availability have played an important role in the population's recovery. The considerable interdecadal differences observed in population growth coincide with remote Arctic and North Atlantic oceanographic processes that link to the Gulf of Maine ecosystem. Here, we build capture-recapture models to quantify the role of prey availability on right whale demographic transitional probabilities and use a corresponding demographic model to project population growth rates into the next century. Contrary to previous predictions, the right whale population is projected to recover in the future as long as prey availability and mortality rates remain within the ranges observed during 1980–2012. However, recent events indicate a northward range shift in right whale prey, potentially resulting in decreased prey availability and/or an expansion of right whale habitat into unprotected waters. An annual increase in the number of whale deaths comparable to that observed during the summer 2017 mass mortality event may cause a decline to extinction even under conditions of normal prey availability. This study highlights the importance of understanding the oceanographic context for observed population changes when evaluating the efficacy of conservation management plans for endangered marine species. Continue reading
Posted Nov 12, 2017 at Constantine Alexander's Journal
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A new 6 million euro project funded by the EU's Horizon 2020 program examines jellyfish as a commercial product. Cotylorhiza tuberculata is sometimes called the fried egg jellyfish. Credit: Tihomir Makovec. Global climate change and the human impact on marine ecosystems have led to dramatic decreases in the number of... Continue reading
Posted Nov 12, 2017 at Constantine Alexander's Journal
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The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows—referred to as the abyssal overturning circulation—is key to quantifying the ocean’s ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32° S, the depth distribution of the seafloor compels dense southern-origin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure. Continue reading
Posted Nov 12, 2017 at Constantine Alexander's Journal
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Explosion of rats, clovers, bedbugs, mosquitoes unintended evolutionary consequence of urbanization. In “Evolution of Life in Urban Environments,” Munshi-South and Johnson show how the study of urban evolution has been documented in cities all across the globe. In this accompanying map, blue silhouettes represent the approximate regions of origin of... Continue reading
Posted Nov 5, 2017 at Constantine Alexander's Journal
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Many commercial fisheries are threatened by overharvesting. However, they can't address the problem because of inadequate scientific information, from overall population numbers to data on how fast fish grow and reproduce. Researchers have developed a model using information about landed fish catches and prices for any species. This model allows fisheries to net enough to meet rising demand while ensuring adequate income and replenishment of natural stocks. Continue reading
Posted Nov 4, 2017 at Constantine Alexander's Journal
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The world's most prestigious award for pioneers in environmental science was given to Hans Joachim Schellnhuber this week in Tokyo. Kazuhiko Ishimura, Chairman of the Asahi Glass Foundation, and Hans Joachim Schellnhuber. Photo: Asahi Glass Foundation The world's most prestigious award for pioneers in environmental science was given to Hans... Continue reading
Posted Oct 29, 2017 at Constantine Alexander's Journal
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Research counters earlier thinking that food chains remain constant through time. Skin cells collected from common dolphins revealed sharp changes in the marine food web off Southern California. Credit: Lindsey E. Peavey (NOAA/CINMS) Environmental disturbances such as El Niño shake up the marine food web off Southern California, new research... Continue reading
Posted Oct 28, 2017 at Constantine Alexander's Journal
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VaquitaCPR demonstrating success in locating endangered Vaquita Porpoises as field operations continue. Team members from the VaquitaCPR project lift a vaquita porpoise into a rescue boat. Credit: VaquitaCPR Scientists with the VaquitaCPR conservation project and Mexico's Secretary of the Environment Rafael Pacchiano announced they succeeded in locating and rescuing a... Continue reading
Posted Oct 28, 2017 at Constantine Alexander's Journal
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Newly funded EU Horizon 2020 project CLAIM seeks to develop and apply innovative marine cleaning technologies and approaches. CLAIM's In-situ testing areas across the Mediterranean and the Baltic Sea (Baltic Sea (near Denmark), Lyon Gulf, Ligurian Sea, Saronikos Gulf). Credit: CLAIM CC-BY 4.0 Newly funded, EU Horizon 2020 project targets... Continue reading
Posted Oct 28, 2017 at Constantine Alexander's Journal
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Encephalization, or brain expansion, underpins humans’ sophisticated social cognition, including language, joint attention, shared goals, teaching, consensus decision-making and empathy. These abilities promote and stabilize cooperative social interactions, and have allowed us to create a ‘cognitive’ or ‘cultural’ niche and colonize almost every terrestrial ecosystem. Cetaceans (whales and dolphins) also have exceptionally large and anatomically sophisticated brains. Here, by evaluating a comprehensive database of brain size, social structures and cultural behaviours across cetacean species, we ask whether cetacean brains are similarly associated with a marine cultural niche. Continue reading
Posted Oct 22, 2017 at Constantine Alexander's Journal
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These whales may use both aerobic and anaerobic respiration to dive for prey. Beaked whale. Credit: Bahamas Marine Mammal Research Organization. Two relatively small beaked whale species took exceptionally long, deep dives while foraging in the Bahamas, confounding expectations that larger whales dive should be able to dive for longer... Continue reading
Posted Oct 15, 2017 at Constantine Alexander's Journal
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Fewer than 30 vaquitas left; project aims for temporary sanctuary. An international team of experts has gathered in San Felipe, Mexico at the request of the Mexican government (SEMARNAT) and has begun a bold, compassionate plan known as VaquitaCPR to save the endangered vaquita porpoise from extinction. The vaquita porpoise,... Continue reading
Posted Oct 15, 2017 at Constantine Alexander's Journal
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Five years after the Fukushima Dai-ichi Nuclear Power Plant accident, the highest radiocesium (137Cs) activities outside of the power plant site were observed in brackish groundwater underneath sand beaches. We hypothesize that the radiocesium was deposited on mineral surfaces in the days and weeks after the accident through wave- and tide-driven exchange of seawater through the beach face. As seawater radiocesium concentrations decreased, this radiocesium reentered the ocean via submarine groundwater discharge, at a rate on par with direct discharge from the power plant and river runoff. This new unanticipated pathway for the storage and release of radionuclides to ocean should be taken into account in the management of coastal areas where nuclear power plants are situated. Continue reading
Posted Oct 8, 2017 at Constantine Alexander's Journal
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Hurricane Irma storm surge takes heavy toll on one of world's most important nesting areas. Hurricane Irma took a devastating toll on incubating sea turtle nests in the Archie Carr National Wildlife Refuge, one of the most important loggerhead and green turtle nesting sites in the world, according to new... Continue reading
Posted Oct 7, 2017 at Constantine Alexander's Journal
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The European Commission has approved an investment package of €222 million from the EU budget to support Europe's transition to more sustainable and low-carbon future under the LIFE programme for the Environment and Climate Action. The EU funding will mobilise additional investments leading to a total of €379 million going... Continue reading
Posted Oct 1, 2017 at Constantine Alexander's Journal
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The history of the Earth system is a story of change. Some changes are gradual and benign, but others, especially those associated with catastrophic mass extinction, are relatively abrupt and destructive. What sets one group apart from the other? Here, I hypothesize that perturbations of Earth’s carbon cycle lead to mass extinction if they exceed either a critical rate at long time scales or a critical size at short time scales. By analyzing 31 carbon isotopic events during the past 542 million years, I identify the critical rate with a limit imposed by mass conservation. Identification of the crossover time scale separating fast from slow events then yields the critical size. The modern critical size for the marine carbon cycle is roughly similar to the mass of carbon that human activities will likely have added to the oceans by the year 2100. Continue reading
Posted Sep 23, 2017 at Constantine Alexander's Journal
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A study on damage to coastal considered only real estate loss. If nothing is done, researchers say, losses might be up to ten times higher if the predicament includes the spreading of flood- and global warming -related diseases. A study on damage to coastal considered only real estate loss. If... Continue reading
Posted Sep 17, 2017 at Constantine Alexander's Journal