scholarly journals Thirty years after - dramatic change in the coastal marine habitats of Kos Island (Greece), 1981-2013.

2014 ◽  
Vol 15 (3) ◽  
pp. 482 ◽  
Author(s):  
C. N. BIANCHI ◽  
M. CORSINI-FOKA ◽  
C. MORRI ◽  
A. ZENETOS
Keyword(s):  
Regime Shift ◽  
Human Impacts ◽  
Rocky Reef ◽  
Multivariate Techniques ◽  
Visual Census ◽  
Biological Communities ◽  
Marine Habitats ◽  
Coastal Marine ◽  
Thermophilic Species ◽  
Available Information

Results of recent fieldwork were compared with data collected in 1981, taken as a reference condition. Surveys were conducted with the same method (time-based visual census along random paths), in the same sites, by the same people. Semi-quantitative inventories of conspicuous species were analysed by univariate and multivariate techniques. Available information on the main potential stressors indicated that a regime shift has occurred in these 30+ years: sea surface temperature rose by1-2°C, human pressure grew impressively, and invasion by several alien species took place. Consistently, a phase shift occurred in the biological communities. Of the 120 conspicuous species found in total, only 51 were common to both surveys; 31 species (‘losses’) were found in 1981 but not again in 2013, 38 (‘gains’) were found exclusively in 2013, 16 (‘winners’) increased their abundance, 8 (‘losers’) got scarcer, and 27 underwent little or no change. Gains included 7 alien, 2 nitrophilic, and 7 thermophilic species. Multivariate analysis evidenced biotic homogenisation in 2013 and huge change in rocky reef habitats. The once flourishing algal forests have disappeared to leave space to sponges and wide areas of bare substratum. This has most probably been the result of overgrazing by alien herbivorous fishes (Siganus luridus and S. rivulatus), whose establishment and spread has been favoured by seawater warming; the synergic action of local human impacts was also evidenced.

scholarly journals Spatial models to support the management of coastal marine ecosystems: a short review of the best practices in Liguria, Italy

2013 ◽  
Vol 15 (1) ◽  
pp. 189 ◽  
Author(s):  
M. VACCHI ◽  
M. MONTEFALCONE ◽  
V. PARRAVICINI ◽  
A. ROVERE ◽  
P. VASSALLO ◽  
...  
Keyword(s):  
Human Impacts ◽  
Spatial Models ◽  
Short Review ◽  
Posidonia Oceanica ◽  
Spatial Modelling ◽  
Coastal Development ◽  
Marine Habitat ◽  
Marine Habitats ◽  
Coastal Marine ◽  
The Status

Spatial modelling is an emerging approach to the management of coastal marine habitats, as it helps understanding and predicting the results of global change. This paper reviews critically two recent examples developed in Liguria, an administrative region of NW Italy. The first example, aiming at predicting habitat status depending on pressures, provides managers with the opportunity of envisaging different scenarios for the consequences of coastal development choices. The second example defines the status of an important Mediterranean coastal marine habitat (Posidonia oceanica meadows) under natural conditions, allowing for quantifying human impacts on regressed meadows. Both modelling approaches are useful to define the targets of coastal management, and may help choosing the best management option. Well-planned and sustained monitoring is essential to model validation and improvement.

scholarly journals Functional diversity of phytoplankton highlights long-term gradual regime shift in the middle section of the Danube River due to global warming, human impacts and oligotrophication

2018 ◽  
Vol 63 (5) ◽  
pp. 456-472 ◽  
Author(s):  
András Abonyi ◽  
Éva Ács ◽  
András Hidas ◽  
István Grigorszky ◽  
Gábor Várbíró ◽  
...  
Keyword(s):  
Global Warming ◽  
Functional Diversity ◽  
Regime Shift ◽  
Human Impacts ◽  
Danube River ◽  
Middle Section ◽  
The Danube River

Waterbirds as indicators of ecosystem health in the coastal marine habitats of southern Florida: 1. Selection and justification for a suite of indicator species

2014 ◽  
Vol 44 ◽  
pp. 148-163 ◽  
Author(s):  
John C. Ogden ◽  
John D. Baldwin ◽  
Oron L. Bass ◽  
Joan A. Browder ◽  
Mark I. Cook ◽  
...  
Keyword(s):  
Indicator Species ◽  
Ecosystem Health ◽  
Marine Habitats ◽  
Coastal Marine ◽  
Southern Florida

scholarly journals A global algorithm for identifying changing streamflow regimes: application to Canadian natural streams (1966–2010)

2021 ◽  
Vol 25 (9) ◽  
pp. 5193-5217
Author(s):  
Masoud Zaerpour ◽  
Shadi Hatami ◽  
Javad Sadri ◽  
Ali Nazemi
Keyword(s):  
Climate Change ◽  
Regime Shift ◽  
Temporal Variations ◽  
Natural Streams ◽  
Regime Types ◽  
Finite Set ◽  
Streamflow Regime ◽  
Available Information ◽  
Global Algorithm ◽  
Impacts Of Climate Change

Abstract. Climate change affects natural streamflow regimes globally. To assess alterations in streamflow regimes, typically temporal variations in one or a few streamflow characteristics are taken into account. This approach, however, cannot see simultaneous changes in multiple streamflow characteristics, does not utilize all the available information contained in a streamflow hydrograph, and cannot describe how and to what extent streamflow regimes evolve from one to another. To address these gaps, we conceptualize streamflow regimes as intersecting spectrums that are formed by multiple streamflow characteristics. Accordingly, the changes in a streamflow regime should be diagnosed through gradual, yet continuous changes in an ensemble of streamflow characteristics. To incorporate these key considerations, we propose a generic algorithm to first classify streams into a finite set of intersecting fuzzy clusters. Accordingly, by analyzing how the degrees of membership to each cluster change in a given stream, we quantify shifts from one regime to another. We apply this approach to the data, obtained from 105 natural Canadian streams, during the period of 1966 to 2010. We show that natural streamflow in Canada can be categorized into six regime types, with clear hydrological and geographical distinctions. Analyses of trends in membership values show that alterations in natural streamflow regimes vary among different regions. Having said that, we show that in more than 80 % of considered streams, there is a dominant regime shift that can be attributed to simultaneous changes in streamflow characteristics, some of which have remained previously unknown. Our study not only introduces a new globally relevant algorithm for identifying changing streamflow regimes but also provides a fresh look at streamflow alterations in Canada, highlighting complex and multifaceted impacts of climate change on streamflow regimes in cold regions.

scholarly journals Missing the Forest and the Trees: Utility, Limits and Caveats for Drone Imaging of Coastal Marine Ecosystems

2021 ◽  
Vol 13 (16) ◽  
pp. 3136
Author(s):  
Leigh W. Tait ◽  
Shane Orchard ◽  
David R. Schiel
Keyword(s):  
Remote Sensing ◽  
Human Impacts ◽  
Management Strategies ◽  
Marine Ecosystems ◽  
Rocky Intertidal ◽  
Small Subset ◽  
Coastal Marine ◽  
Comprehensive Knowledge ◽  
Coastal Marine Ecosystems

Coastal marine ecosystems are under stress, yet actionable information about the cumulative effects of human impacts has eluded ecologists. Habitat-forming seaweeds in temperate regions provide myriad irreplaceable ecosystem services, but they are increasingly at risk of local and regional extinction from extreme climatic events and the cumulative impacts of land-use change and extractive activities. Informing appropriate management strategies to reduce the impacts of stressors requires comprehensive knowledge of species diversity, abundance and distributions. Remote sensing undoubtedly provides answers, but collecting imagery at appropriate resolution and spatial extent, and then accurately and precisely validating these datasets is not straightforward. Comprehensive and long-running monitoring of rocky reefs exist globally but are often limited to a small subset of reef platforms readily accessible to in-situ studies. Key vulnerable habitat-forming seaweeds are often not well-assessed by traditional in-situ methods, nor are they well-captured by passive remote sensing by satellites. Here we describe the utility of drone-based methods for monitoring and detecting key rocky intertidal habitat types, the limitations and caveats of these methods, and suggest a standardised workflow for achieving consistent results that will fulfil the needs of managers for conservation efforts.

Costs and benefits of towed videos and remotely operated vehicles for sampling shallow reef habitats and fish

2020 ◽  
Vol 71 (8) ◽  
pp. 953 ◽  
Author(s):  
T. R. Davis ◽  
G. Cadiou ◽  
J. Williams ◽  
M. A. Coleman
Keyword(s):  
Fish Assemblages ◽  
Selection Process ◽  
Low Cost ◽  
Rocky Reef ◽  
Costs And Benefits ◽  
Remotely Operated Vehicles ◽  
Benthic Habitats ◽  
Comparative Performance ◽  
Shallow Reef ◽  
Marine Habitats

Where several different tools are available for research, the costs and benefits associated with each option become an important part of the selection process. Towed video (ToV) and remotely operated vehicles (ROVs) are both widely used to assess shallow reef benthic habitats and fish assemblages, but quantitative data on their comparative performance is limited. The relative abilities of commercially available ToV and ROV were assessed using two low-cost (less than A$10000), manually deployable systems. These systems were deployed to collect photographs of marine habitats and videos of fish assemblages along six 200-m transects at three separate sites. The time required to operate each system and the specific limitations and advantages of each system were compared. Both systems performed equally in terms of the resolution of data collected on benthic habitats and fish assemblages on shallow reefs. However, ToV required significantly less time (~60% less) to collect data than ROV, and should allow cost savings with no loss in data quality. We recommend ToV as a cost-effective and easily deployable system for assessing rocky reef habitats and fish assemblages.

Diets and trophic guilds of small fishes from coastal marine habitats in western Taiwan

2017 ◽  
Vol 91 (1) ◽  
pp. 331-345 ◽  
Author(s):  
J. P. Egan ◽  
U.-S. Chew ◽  
C.-H. Kuo ◽  
V. Villarroel-Diaz ◽  
P. J. Hundt ◽  
...  
Keyword(s):  
Trophic Guilds ◽  
Marine Habitats ◽  
Coastal Marine

scholarly journals Effects of Natural and Anthropogenic Stressors on Fucalean Brown Seaweeds Across Different Spatial Scales in the Mediterranean Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Sotiris Orfanidis ◽  
Fabio Rindi ◽  
Emma Cebrian ◽  
Simonetta Fraschetti ◽  
Ina Nasto ◽  
...  
Keyword(s):  
Habitat Degradation ◽  
Human Impacts ◽  
Spatial Scales ◽  
Percentage Cover ◽  
Ecological Processes ◽  
Brown Seaweeds ◽  
Anthropogenic Stressors ◽  
Marine Habitats ◽  
Cystoseira Compressa ◽  
The Mediterranean

Algal habitat-forming forests composed of fucalean brown seaweeds (Cystoseira, Ericaria, and Gongolaria) have severely declined along the Mediterranean coasts, endangering the maintenance of essential ecosystem services. Numerous factors determine the loss of these assemblages and operate at different spatial scales, which must be identified to plan conservation and restoration actions. To explore the critical stressors (natural and anthropogenic) that may cause habitat degradation, we investigated (a) the patterns of variability of fucalean forests in percentage cover (abundance) at three spatial scales (location, forest, transect) by visual estimates and or photographic sampling to identify relevant spatial scales of variation, (b) the correlation between semi-quantitative anthropogenic stressors, individually or cumulatively (MA-LUSI index), including natural stressors (confinement, sea urchin grazing), and percentage cover of functional groups (perennial, semi-perennial) at forest spatial scale. The results showed that impacts from mariculture and urbanization seem to be the main stressors affecting habitat-forming species. In particular, while mariculture, urbanization, and cumulative anthropogenic stress negatively correlated with the percentage cover of perennial fucalean species, the same stressors were positively correlated with the percentage cover of the semi-perennial Cystoseira compressa and C. compressa subsp. pustulata. Our results indicate that human impacts can determine spatial patterns in these fragmented and heterogeneous marine habitats, thus stressing the need of carefully considering scale-dependent ecological processes to support conservation and restoration.

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