scholarly journals Human activity selectively impacts the ecosystem roles of parrotfishes on coral reefs

2011 ◽  
Vol 279 (1733) ◽  
pp. 1621-1629 ◽  
Author(s):  
David R. Bellwood ◽  
Andrew S. Hoey ◽  
Terence P. Hughes

Around the globe, coral reefs and other marine ecosystems are increasingly overfished. Conventionally, studies of fishing impacts have focused on the population size and dynamics of targeted stocks rather than the broader ecosystem-wide effects of harvesting. Using parrotfishes as an example, we show how coral reef fish populations respond to escalating fishing pressure across the Indian and Pacific Oceans. Based on these fish abundance data, we infer the potential impact on four key functional roles performed by parrotfishes. Rates of bioerosion and coral predation are highly sensitive to human activity, whereas grazing and sediment removal are resilient to fishing. Our results offer new insights into the vulnerability and resilience of coral reefs to the ever-growing human footprint. The depletion of fishes causes differential decline of key ecosystem functions, radically changing the dynamics of coral reefs and setting the stage for future ecological surprises.

2017 ◽  
Vol 114 (34) ◽  
pp. 8951-8956 ◽  
Author(s):  
Marina Alberti ◽  
Cristian Correa ◽  
John M. Marzluff ◽  
Andrew P. Hendry ◽  
Eric P. Palkovacs ◽  
...  

Humans challenge the phenotypic, genetic, and cultural makeup of species by affecting the fitness landscapes on which they evolve. Recent studies show that cities might play a major role in contemporary evolution by accelerating phenotypic changes in wildlife, including animals, plants, fungi, and other organisms. Many studies of ecoevolutionary change have focused on anthropogenic drivers, but none of these studies has specifically examined the role that urbanization plays in ecoevolution or explicitly examined its mechanisms. This paper presents evidence on the mechanisms linking urban development patterns to rapid evolutionary changes for species that play important functional roles in communities and ecosystems. Through a metaanalysis of experimental and observational studies reporting more than 1,600 phenotypic changes in species across multiple regions, we ask whether we can discriminate an urban signature of phenotypic change beyond the established natural baselines and other anthropogenic signals. We then assess the relative impact of five types of urban disturbances including habitat modifications, biotic interactions, habitat heterogeneity, novel disturbances, and social interactions. Our study shows a clear urban signal; rates of phenotypic change are greater in urbanizing systems compared with natural and nonurban anthropogenic systems. By explicitly linking urban development to traits that affect ecosystem function, we can map potential ecoevolutionary implications of emerging patterns of urban agglomerations and uncover insights for maintaining key ecosystem functions upon which the sustainability of human well-being depends.


2021 ◽  
Vol 8 ◽  
Author(s):  
Laurence H. De Clippele ◽  
Denise Risch

This study compares the noise levels at the cold-water coral Tisler reef, before and after the closure of the border between Norway and Sweden, which occurred as a direct result of the COVID-19 pandemic. The Tisler reef is a marine protected area located under a ferry “highway” that connects Norway and Sweden. Cold-water coral reefs are recognised as being important hotspots of both biodiversity and biomass, they function as breeding and nursing grounds for commercially important fish and are essential in providing ecosystem functions. Whilst studies have shown that fishery, ocean warming, and acidification threaten them, the effects of noise pollution on cold-water coral reefs remains unstudied. To study the severity of noise pollution at the Tisler reef, a long-term acoustic recorder was deployed from 29 January 2020 until 26 May 2020. From 15 March COVID-19 lockdown measures stopped passenger vessel traffic between Norway and Sweden. This study found that the overall noise levels were significantly lower after border closure, due to reduced ferry traffic, wind speeds, and sea level height. When comparing the median hourly noise levels of before vs. after border closure, this study measured a significant reduction in the 63–125 Hz 1/3 octave band noise levels of 8.94 ± 0.88 (MAD) dB during the day (07:00:00–19:59:59) and 1.94 ± 0.11 (MAD) dB during the night (20:00:00–06:59:59). Since there was no ferry traffic during the night, the drop in noise levels at night was likely driven by seasonal changes, i.e., the reduction in wind speed and sea level height when transitioning from winter to spring. Taking into account this seasonal effect, it can be deduced that the COVID-19 border closure reduced the noise levels in the 63–125 Hz 1/3 octave bands at the Tisler reef by 7.0 ± 0.99 (MAD) dB during the day. While the contribution of, and changes in biological, weather-related and geophysical sound sources remain to be assessed in more detail, understanding the extent of anthropogenic noise pollution at the Tisler cold-water coral reef is critical to guide effective management to ensure the long-term health and conservation of its ecosystem functions.


Author(s):  
Jenny E House ◽  
Luc M Bidaut ◽  
Alec P Christie ◽  
Oscar Pizarro ◽  
Maria Dornelas

Coral reefs are a valuable and vulnerable marine ecosystem. The structure of coral reefs influences their health and ability to fulfill ecosystem functions and services. However, monitoring reef corals largely relies on 1D or 2D estimates of coral cover and abundance that overlook change in ecologically significant aspects of the reefs because they do not incorporate vertical or volumetric information. This study explores the relationship between 2D and 3D metrics of coral size. We show that surface area and volume scale consistently with planar area, albeit with morphotype specific conversion parameters. We use a photogrammetric approach using open-source software to estimate the ability of photogrammetry to provide measurement estimates of corals in 3D. Technological developments have made photogrammetry a valid and practical technique for studying coral reefs. We anticipate that these techniques for moving coral research from 2D into 3D will facilitate answering ecological questions by incorporating the 3rd dimension into monitoring.


Author(s):  
S. A. Nta ◽  
M. J. Ayotamuno ◽  
A. H. Igoni ◽  
R. N. Okparanma

This paper presents potential impact on health of emission from landfill site on Uyo village road, Uyo local government area of Akwa Ibom State, Nigeria. Three sampling points were assessed for particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide H2S, ammonia (NH3), total volatile organic carbon (TVOC) and hydrogen cyanide (HCN) using highly sensitive digital portable meters. The data obtained were expressed in terms of an air quality index. Air quality index indicates that the ambient air can be described as unhealthy for sensitive groups for NO2, unhealthy for SO2 and PM2.5 and moderate for CO, respectively. H2S, NH3, TVOC, HCN, PM10 were not indicated in USEPA air quality standards. It recommended that stringent and proper landfill emissions management together with appropriate burning of wastes should be considered in the study area to ease the risks associated with these pollutants on public health.


2019 ◽  
Vol 119 ◽  
pp. 00012 ◽  
Author(s):  
Caterina Mele

The human habitation of the surface of the planet has led, especially since the mid-twentieth century, to an enormous increase in the built up area. This phenomenon concerns both the oldest industrialised countries, such as European Union and the United States, and the so-called emerging countries in Asia, Africa and Latin America.The urbanised built area has increased in different ways, but has led everywhere to the destruction of large portions of virgin soil, the loss of biodiversity in the number and type of species in fauna and flora, and often the total or partial impairment of ecosystem functions of enormous environmental value (such as the evapotransportive mechanisms of soil and vegetation). Although the curve of global population growth is slowing, the growth of urban areas continues to expand, even in countries which have long been industrialised, where the spread of building has given rise to cities dispersed over a territory so that there is no longer a recognisable clear division between the city and the countryside. In fact, contemporary cities are the main consumers of all environmental resources, from water to food, including energy and environmental stressors, and are responsible for 80% of CO2 emissions into the atmosphere. The ecosystem surface required to sustain a large city on the planet today canbe about 200 times larger than its physical size. The urban civilisation of the 21st century, which at a superficial glance may appear as a symbol of the human capacity to radically adapt and transform the natural habitat toits own needs, is also a witness to the unsustainability of the human footprint on earth. Radically rethinking cities and human settlements entails an equally radical rethinking of our economic and development model, but it is a necessary and strategic task if we really want to face the challenge of sustainability with appropriate instruments.


2019 ◽  
Vol 97 (9) ◽  
pp. 755-762 ◽  
Author(s):  
Michel J. Kaiser

Bottom trawling accounts for nearly a quarter of wild-capture seafood production, but it is associated with physical disturbance of the seabed leading to changes in benthic abundance, habitat structure, and biogeochemical processes. Understanding the processes of benthic depletion and recovery in relation to different types of fishing gears, and in different seabed types, is an important pre-requisite to inform appropriate management measures to limit or reduce the effects of trawling on the seabed. The combined approaches of meta-analysis and modelling that link fishing-gear penetration of the seabed to benthic depletion, and recovery to taxon longevity, have enabled the development of a modelling framework to estimate relative benthic status in areas subject to trawling. Such estimations are highly sensitive to the spatial resolution at which fishing footprint (trawl track) data are aggregated, and this leads to overinflated estimates of fishing impacts on benthos when coarse-level aggregation is applied. These approaches present a framework into which other “sustainability” criteria can be added, e.g., the consideration of carbon footprints of fishing activities.


Author(s):  
Janice Cristine Thiél ◽  
Sandra Batista da Costa

The Pragmatics Collection, organized by the Language, Communication and Cognition Research Group CNPq, aims to present scientific research carried out in this area in its multiple dialogues with other sciences, such as neuroscience, biology, psychology, social sciences, literary studies, law , translation, social communication, among many others, as well as disseminating research applied to the most diverse contexts of human activity . This inaugural volume includes research by national and foreign doctoral professors, signed jointly with colleagues and students, with the purpose of both strengthening the exchange of ideas at ABRAP - Brazilian Association of Pragmatics, as well as maximizing the reach, originality, potential impact and interdisciplinarity of this science in Brazil


Author(s):  
Mariana Paula Muñoz Arruda

The Pragmatics Collection, organized by the Language, Communication and Cognition Research Group CNPq, aims to present scientific research carried out in this area in its multiple dialogues with other sciences, such as neuroscience, biology, psychology, social sciences, literary studies, law , translation, social communication, among many others, as well as disseminating research applied to the most diverse contexts of human activity . This inaugural volume includes research by national and foreign doctoral professors, signed jointly with colleagues and students, with the purpose of both strengthening the exchange of ideas at ABRAP - Brazilian Association of Pragmatics, as well as maximizing the reach, originality, potential impact and interdisciplinarity of this science in Brazil.


2020 ◽  
Vol 287 (1921) ◽  
pp. 20192214 ◽  
Author(s):  
Laura E. Richardson ◽  
Nicholas A. J. Graham ◽  
Andrew S. Hoey

Rapid and unprecedented ecological change threatens the functioning and stability of ecosystems. On coral reefs, global climate change and local stressors are reducing and reorganizing habitat-forming corals and associated species, with largely unknown implications for critical ecosystem functions such as herbivory. Herbivory mediates coral–algal competition, thereby facilitating ecosystem recovery following disturbance such as coral bleaching events or large storms. However, relationships between coral species composition, the distribution of herbivorous fishes and the delivery of their functional impact are not well understood. Here, we investigate how herbivorous fish assemblages and delivery of two distinct herbivory processes, grazing and browsing, differ among three taxonomically distinct, replicated coral habitats. While grazing on algal turf assemblages was insensitive to different coral configurations, browsing on the macroalga Laurencia cf. obtusa varied considerably among habitats, suggesting that different mechanisms may shape these processes. Variation in browsing among habitats was best predicted by the composition and structural complexity of benthic assemblages (in particular the cover and composition of corals, but not macroalgal cover), and was poorly reflected by visual estimates of browser biomass. Surprisingly, the lowest browsing rates were recorded in the most structurally complex habitat, with the greatest cover of coral (branching Porites habitat). While the mechanism for the variation in browsing is not clear, it may be related to scale-dependent effects of habitat structure on visual occlusion inhibiting foraging activity by browsing fishes, or the relative availability of alternate dietary resources. Our results suggest that maintained functionality may vary among distinct and emerging coral reef configurations due to ecological interactions between reef fishes and their environment determining habitat selection.


2019 ◽  
Vol 286 (1897) ◽  
pp. 20182672 ◽  
Author(s):  
Alexandre C. Siqueira ◽  
David R. Bellwood ◽  
Peter F. Cowman

Herbivory by fishes has been identified as a key ecological process shaping coral reefs through time. Although taxonomically limited, herbivorous reef fishes display a wide range of traits, which results in varied ecosystem functions on reefs around the world. Yet, we understand little about how these trait combinations and functions in ecosystems changed through time and across biogeographic realms. Here, we used fossils and phylogenies in a functional ecological framework to reveal temporal changes in nominally herbivorous fish assemblages among oceanic basins in both trait space and lineage richness among functions. We show that the trait space occupied by extant herbivorous fishes in the Indo-Pacific resulted from an expansion of traits from the ancestral Tethyan assemblages. By contrast, trait space in the Atlantic is the result of lineage turnover, with relatively recent colonization by lineages that arose in the east Tethys/Indo-Pacific. From an ecosystem function perspective, the Atlantic supports a depauperate fauna, with few extant herbivorous reef fish lineages performing each function. Indo-Pacific fishes support both more functions and more lineages within each function, with a marked Miocene to Pleistocene expansion. These disparities highlight the importance of history in explaining global variation in fish functional composition on coral reefs.


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