scholarly journals Climate-driven range expansion of a critically endangered top predator in northeast Atlantic waters

2007 ◽  
Vol 3 (5) ◽  
pp. 529-532 ◽  
Author(s):  
Russell B Wynn ◽  
Simon A Josey ◽  
Adrian P Martin ◽  
David G Johns ◽  
Pierre Yésou
Keyword(s):  
Range Expansion ◽  
Regime Shift ◽  
Global Climate ◽  
Trophic Levels ◽  
Critically Endangered ◽  
Northeast Atlantic ◽  
Conservation Implications ◽  
Top Predators ◽  
Distribution Shifts ◽  
New Evidence

Global climate change is driving rapid distribution shifts in marine ecosystems; these are well established for lower trophic levels, but are harder to quantify for migratory top predators. By analysing a 25-year sightings-based dataset, we found evidence for rapid northwards range expansion of the critically endangered Balearic shearwater Puffinus mauretanicus in northeast Atlantic waters. A 0.6°C sea surface temperature increase in the mid-1990s is interpreted as an underlying controlling factor, while simultaneous northward shifts of plankton and prey fish species suggests a strong bottom-up control. Our results have important conservation implications and provide new evidence for climate-driven regime shift in Atlantic ecosystems.

scholarly journals Reply to comment: is climate change the most likely driver of range expansion of a critically endangered top predator in northeast Atlantic waters?

2008 ◽  
Vol 4 (2) ◽  
pp. 206-207 ◽  
Author(s):  
Russell B Wynn ◽  
Simon A Josey ◽  
Adrian P Martin ◽  
David G Johns ◽  
Pierre Yésou
Keyword(s):  
Climate Change ◽  
Range Expansion ◽  
Critically Endangered ◽  
Top Predator ◽  
Northeast Atlantic

Trophic Cascades in Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Indirect Effects ◽  
Prey Species ◽  
Trophic Levels ◽  
Herbaceous Plant ◽  
Direct Effects ◽  
Temperate Grasslands ◽  
Cascading Effect ◽  
Top Predators ◽  
Invertebrate Predators ◽  
Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

scholarly journals Fine-scale structures as spots of increased fish concentration in the open ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alberto Baudena ◽  
Enrico Ser-Giacomi ◽  
Donatella D’Onofrio ◽  
Xavier Capet ◽  
Cedric Cotté ◽  
...  
Keyword(s):  
Coherent Structures ◽  
Trophic Levels ◽  
Fish Distribution ◽  
Lagrangian Coherent Structures ◽  
Mesopelagic Fish ◽  
Fine Scale ◽  
Conservation Policies ◽  
Top Predators ◽  
Frontal Zones ◽  
Spatio Temporal

AbstractOceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.

scholarly journals New distributional record of Anthrenus dorsatus Mulsant & Rey, 1868 (Coleoptera, Dermestidae), Thessaloniki, Greece

Check List ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1077-1081 ◽  
Author(s):  
Graham J. Holloway ◽  
Dimitrios E. Bakaloudis
Keyword(s):  
Climate Change ◽  
North Africa ◽  
Global Climate Change ◽  
Range Expansion ◽  
Mediterranean Basin ◽  
Global Climate ◽  
Species Group ◽  
Western Mediterranean ◽  
Western Mediterranean Basin

Anthrenus dorsatus Mulsant & Rey, 1868 has been recorded from North Africa, Malta, and Iberia. During a recent visit to Thessaloniki, Greece, several Anthrenus species were collected, including A. dorsatus. The previously known distribution of A. dorsatus suggested that this species was restricted to the western Mediterranean basin, possibly with a coastal bias. This record extends the known range of A. dorsatus farther east and providing more evidence of range expansion in the pimpinellae species group across Europe, possibly driven by global climate change.

scholarly journals Predation-Driven Spillover: Pathogen Bioaccumulation in Top Predators

2020 ◽  
Author(s):  
Jennifer Malmberg ◽  
Lauren White ◽  
Sue Vandewoude
Keyword(s):  
Empirical Research ◽  
Threatened Species ◽  
Disease Risk ◽  
High Morbidity ◽  
Infectious Agents ◽  
Disease Dynamics ◽  
Sensitive Species ◽  
Predator Prey ◽  
Conservation Implications ◽  
Top Predators

Predator-prey interactions present heightened opportunities for pathogen spillover, as predators are exposed to novel parasites through consumption of prey harboring potentially infectious agents. Epizootics with high morbidity and mortality have been recorded following prey-to-predator spillover events with significant conservation implications, particularly for sensitive species. However, relatively few virulent infections following prey consumption are reported, given the very large number of exposures that presumably occur. Further, many transmitted agents are infectious but clinically silent and thus go unrecognized. Mechanisms that determine outcome of predator exposure to prey-based pathogens therefore represent an important, understudied component of disease dynamics that should be considered in modeling approaches and empirical research to better understand disease risk and emergence, particularly in vulnerable or threatened species.

Prey consumption estimates for salmon sharks

2019 ◽  
Vol 70 (6) ◽  
pp. 824 ◽  
Author(s):  
Kaitlyn A. Manishin ◽  
Kenneth J. Goldman ◽  
Margaret Short ◽  
Curry J. Cunningham ◽  
Peter A. H. Westley ◽  
...  
Keyword(s):  
Life History ◽  
Mass Balance ◽  
Marine Mammals ◽  
Extreme Values ◽  
Assimilation Efficiency ◽  
Prey Consumption ◽  
Trophic Levels ◽  
Shark Species ◽  
Top Predators ◽  
Balance Technique

Top predators, such as salmon sharks (Lamna ditropis), can influence the abundance and population structure of organisms at lower trophic levels through direct effects, such as predation mortality, and indirect interactions. As a first step towards better understanding the average annual prey consumption for individual adult salmon sharks, we bracketed consumption estimates using three methods: (1) daily ration requirement; (2) bioenergetic mass balance; and (3) a Bayesian model of shark growth. In the first method, we applied ration estimates for related lamnid shark species that yielded salmon shark estimates of 1461 and 2202kgyear–1. The second method used a mass–balance technique to incorporate life history information from salmon sharks and physiological parameters from other species and produced estimates of 1870, 2070, 1610 and 1762kgyear–1, depending on assumed diet. Growth modelling used salmon shark growth histories and yielded estimates of 16900 or 20800kgyear–1, depending on assumed assimilation efficiency. Of the consumption estimates, those from the mass–balance technique may be the most realistic because they incorporated salmon shark life history data and do not produce extreme values. Taken as a whole, these estimates suggest that salmon sharks have similar energetic requirements to piscivorous marine mammals.

scholarly journals Loss of top-down biotic interactions changes the relative benefits for obligate mutualists

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182501 ◽  
Author(s):  
Rong Wang ◽  
Xiao-Yong Chen ◽  
Yan Chen ◽  
Gang Wang ◽  
Derek W. Dunn ◽  
...  
Keyword(s):  
Biotic Interactions ◽  
Trophic Levels ◽  
Fig Wasp ◽  
Negative Effects ◽  
Top Down ◽  
Top Predators ◽  
Natural Range ◽  
Obligate Mutualism ◽  
The Stability ◽  
Food Web Complexity

The collapse of mutualisms owing to anthropogenic changes is contributing to losses of biodiversity. Top predators can regulate biotic interactions between species at lower trophic levels and may contribute to the stability of such mutualisms, but they are particularly likely to be lost after disturbance of communities. We focused on the mutualism between the fig tree Ficus microcarpa and its host-specific pollinator fig wasp and compared the benefits accrued by the mutualists in natural and translocated areas of distribution. Parasitoids of the pollinator were rare or absent outside the natural range of the mutualists, where the relative benefits the mutualists gained from their interaction were changed significantly away from the plant's natural range owing to reduced seed production rather than increased numbers of pollinator offspring. Furthermore, in the absence of the negative effects of its parasitoids, we detected an oviposition range expansion by the pollinator, with the use of a wider range of ovules that could otherwise have generated seeds. Loss of top-down control has therefore resulted in a change in the balance of reciprocal benefits that underpins this obligate mutualism, emphasizing the value of maintaining food web complexity in the Anthropocene.

New evidence for “far-field” Holocene sea level oscillations and links to global climate records

2018 ◽  
Vol 487 ◽  
pp. 67-73 ◽  
Author(s):  
N.D. Leonard ◽  
K.J. Welsh ◽  
T.R. Clark ◽  
Y.-x. Feng ◽  
J.M. Pandolfi ◽  
...  
Keyword(s):  
Sea Level ◽  
Global Climate ◽  
Far Field ◽  
Climate Records ◽  
Sea Level Oscillations ◽  
New Evidence ◽  
Holocene Sea Level

scholarly journals Effects of Consecutive Extreme Weather Events on a Temperate Dystrophic Lake: A Detailed Insight into Physical, Chemical and Biological Responses

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1411 ◽  
Author(s):  
Maria Calderó-Pascual ◽  
Elvira de Eyto ◽  
Eleanor Jennings ◽  
Mary Dillane ◽  
Mikkel René Andersen ◽  
...  
Keyword(s):  
Global Climate ◽  
Zooplankton Community ◽  
Fold Increase ◽  
Extreme Weather ◽  
Zooplankton Biomass ◽  
Trophic Levels ◽  
Extreme Weather Events ◽  
Weather Events ◽  
Fold Reduction ◽  
Stable Conditions

Between May and July 2018, Ireland experienced an exceptional heat wave, which broke long-term temperature and drought records. These calm, stable conditions were abruptly interrupted by a second extreme weather event, Atlantic Storm Hector, in late June. Using high-frequency monitoring data, coupled with fortnightly biological sampling, we show that the storm directly affected the stratification pattern of Lough Feeagh, resulting in an intense mixing event. The lake restabilised quickly after the storm as the heatwave continued. During the storm there was a three-fold reduction in Schmidt stability, with a mixed layer deepening of 9.5 m coinciding with a two-fold reduction in chlorophyll a but a three-fold increase in total zooplankton biomass. Epilimnetic respiration increased and net ecosystem productivity decreased. The ratio of total nitrogen:total phosphorus from in-lake versus inflow rivers was decoupled, leading to a cascade effect on higher trophic levels. A step change in nitrogen:phosphorus imbalances suggested that the zooplankton community shifted from phosphorus to nitrogen nutrient constraints. Such characterisations of both lake thermal and ecological responses to extreme weather events are relatively rare but are crucial to our understanding of how lakes are changing as the impacts of global climate change accelerate.

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