scholarly journals A Very Large Spawning Aggregation of a Deep-Sea Eel: Magnitude and Status

2021 ◽  
Vol 9 (7) ◽  
pp. 723
Author(s):  
Alan Williams ◽  
Deborah Osterhage ◽  
Franziska Althaus ◽  
Timothy Ryan ◽  
Mark Green ◽  
...  
Keyword(s):  
Deep Sea ◽  
Regional Scale ◽  
National Strategy ◽  
Bottom Trawling ◽  
Marine Park ◽  
Advanced Stages ◽  
Conservation Values ◽  
Very High ◽  
Lines Of Evidence ◽  
Austral Autumn

Multiple lines of evidence substantiate the existence of a very large aggregation of the basketwork eel, Diastobranchus capensis, on the small (3 km2) Patience Seamount off southeast Australia. The aggregation appears to be present year-round, but largest in the austral autumn when composed of spawning eels. Twenty eels caught in April 2015 (14 female, 6 male) were all in advanced stages of spawning condition. The eel’s abundance in the aggregation was very high as measured at seamount, local and regional scales. Hydroacoustic measurement of the spawning aggregation’s dimensions (~100 × 1000 m) and conservative counts of 100 s of eels along camera transects of ~1000–2000 m length indicate 10,000 s individual eels may have been present. The absence of other known spawning locations indicates the Patience Seamount is a regional-scale spatial anchor for spawning. The aggregation was protected in a marine park in 2007 following a decades-long impact from bottom trawling, indicating that the population can be expected to stabilise and recover. Monitoring the aggregation’s status, and validating seasonal spawning, provide important opportunities to examine conservation-led recovery in the deep sea as part of Australia’s new national strategy of Monitoring, Evaluation, Reporting and Improvement (MERI) for conservation values within marine parks.

scholarly journals Central Mediterranean Sea forecast: effects of high-resolution atmospheric forcings

2006 ◽  
Vol 3 (3) ◽  
pp. 637-669 ◽  
Author(s):  
S. Natale ◽  
R. Sorgente ◽  
S. Gaberšek ◽  
A. Ribotti ◽  
A. Olita
Keyword(s):  
High Resolution ◽  
Ocean Circulation ◽  
Regional Scale ◽  
Circulation Model ◽  
Surface Current ◽  
Ocean Model ◽  
Central Mediterranean ◽  
Resolution Model ◽  
Atmospheric Forcings ◽  
Very High

Abstract. Ocean forecasts over the Central Mediterranean, produced by a near real time regional scale system, have been evaluated in order to assess their predictability. The ocean circulation model has been forced at the surface by a medium, high or very high resolution atmospheric forcing. The simulated ocean parameters have been compared with satellite data and they were found to be generally in good agreement. High and very high resolution atmospheric forcings have been able to form noticeable, although short-lived, surface current structures, due to their ability to detect transient atmospheric disturbances. The existence of the current structures has not been directly assessed due to lack of measurements. The ocean model in the slave mode was not able to develop dynamics different from the driving coarse resolution model which provides the boundary conditions.

scholarly journals Evaluating impacts of bottom trawling and hypoxia on benthic communities at the local, habitat, and regional scale using a modelling approach

2019 ◽  
Vol 77 (1) ◽  
pp. 278-289 ◽  
Author(s):  
P D van Denderen ◽  
S G Bolam ◽  
R Friedland ◽  
J G Hiddink ◽  
K Norén ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Regional Scale ◽  
The Baltic Sea ◽  
Benthic Habitats ◽  
Bottom Trawling ◽  
Management Actions ◽  
The Baltic ◽  
Local Habitat

Abstract Bottom trawling disturbance and hypoxia are affecting marine benthic habitats worldwide. We present an approach to predict their effects on benthic communities, and use the approach to estimate the state, the biomass relative to carrying capacity, of the Baltic Sea at the local, habitat, and regional scale. Responses to both pressures are expected to depend on the longevity of fauna, which is predicted from benthic data from 1558 locations. We find that communities in low-salinity regions mostly consist of short-lived species, which are, in our model, more resilient than those of the saline areas. The model predicts that in 14% of the Baltic Sea region benthic biomass is reduced by at least 50%, whereas an additional 8% of the region has reductions of 10–50%. The effects of hypoxia occur over larger spatial scales and lead to a low state of especially deep habitats. The approach is based on a simple characterization of the benthic community, which comes with high uncertainty, but allows for the identification of benthic habitats that are at greatest risk and prioritization of management actions at the regional scale. This information supports the development of sustainable approaches to manage impact of human activities on benthic ecosystems.

Deep-Sea Fishing in the European Mesolithic: Fact or Fantasy?

2004 ◽  
Vol 7 (3) ◽  
pp. 273-290 ◽  
Author(s):  
Catriona Pickard ◽  
Clive Bonsall
Keyword(s):  
Sea Level ◽  
Deep Water ◽  
Deep Sea ◽  
Fishing Gear ◽  
Site Location ◽  
Archaeological Investigation ◽  
Fish Biology ◽  
Ethnographic Data ◽  
Lines Of Evidence

Some previous authors have argued for the practice of offshore, deep-water fishing in the European Mesolithic. In this article, various lines of evidence are brought to bear on this question: the kinds of fishing gear employed, the evidence relating to the use of boats and navigation, site location, ethnographic data, and fish biology and behaviour. It is concluded that the existence of deep-sea fisheries cannot be demonstrated on the basis of the available data. However, around much of Europe Mesolithic shorelines now lie below sea level and the study highlights the need for underwater archaeological investigation of submerged landscapes.

Infaunal macroinvertebrate assemblages of the eastern Great Australian Bight: effectiveness of a marine protected area in representing the region's benthic biodiversity

2009 ◽  
Vol 60 (5) ◽  
pp. 459 ◽  
Author(s):  
David R. Currie ◽  
Shirley J. Sorokin ◽  
Tim M. Ward
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Regional Scale ◽  
Strongly Correlated ◽  
Inner Shelf ◽  
Protection Zone ◽  
Marine Park ◽  
Great Australian Bight ◽  
Deposit Feeding ◽  
Number Of Individuals

Marine reserves are used widely throughout the world to conserve biodiversity, but in many instances uncertainties exist over how well these areas represent biodiversity at a regional scale (i.e. 100–1000 km). In the present study, infaunal assemblages were examined in the eastern Great Australian Bight (GAB) to evaluate the efficacy of the Benthic Protection Zone of the GAB Marine Park in representing regional biodiversity. Distributional patterns in infauna were further examined in relation to epifaunal species composition and environmental conditions to investigate structural forcing. Grab samples of infauna were collected from the same 65 sites sampled in an earlier survey of epifauna. In total, 240 taxa belonging to 11 phyla were collected. Most taxa were uncommon, with 96% representing less than 2% of the total number of individuals collected and 39% occurring at only one site. Unlike the epifauna, the infauna of the eastern GAB does not appear to be particularly diverse. Sessile filter feeders dominated the infaunal communities of the inner shelf, whereas motile, deposit-feeding organisms dominated the shelf break. As was the case with the epifauna, the highest numbers of taxa and individuals were recorded near the head of the bight and in inner-shelf waters off the western Eyre Peninsula, where productivity is enhanced by upwelling. Cluster analysis identified three community groupings, which were strongly correlated with depth. All three communities and 72% (172) of the 240 taxa collected were represented within the Benthic Protection Zone of the GAB Marine Park, confirming findings from the epifaunal survey that this protected area is well placed to represent the benthic biodiversity of the eastern GAB.

Predation on copepods by an Alaskan cladorhizid sponge

2007 ◽  
Vol 87 (6) ◽  
pp. 1721-1726 ◽  
Author(s):  
Les Watling
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lipid Content ◽  
Deep Sea ◽  
Prey Capture ◽  
Primary Process ◽  
High Lipid ◽  
Very High ◽  
Prey Items ◽  
Scanning Electron

Deep water cladorhizids are now generally thought to be carnivorous. While the methods of prey capture have been established for species of Asbestopluma, and perhaps Chondrocladia, information is sparse for species of Cladorhiza. The external morphology of the deep-sea Alaskan species, Cladorhiza corona, was examined immediately after collection, and then again later using scanning electron microscopy (SEM). All sponges examined had captured, and in most cases, fully encased, prey items which for the most part consisted of planktonic copepods. The hypothesis of this paper is that the primary process of prey capture is by means of a sticky substance and that prey stick to the sponge on contact. The abundant cladorhizid anisochelae do not seem to be arranged in a manner such that they can be used for prey capture as has been seen in Asbestopluma. Digestion of the prey occurs in a temporary cavity created by migrating sponge cells. Within this cavity lipid from the copepod is liberated, then absorbed and transported to the central part of the sponge. It is not known how much of the remaining tissue of the copepod is digested. Copepods have very high lipid content so their capture would provide the sponge with abundant energy from each prey item. The sponges seem to have their highest density in areas where bottom flow and migrating copepod numbers are both high.

scholarly journals Deep-Sea Mega-Epibenthic Assemblages from the SW Portuguese Margin (NE Atlantic) Subjected to Bottom-Trawling Fisheries

2017 ◽  
Vol 4 ◽  
Author(s):  
Sofia P. Ramalho ◽  
Lidia Lins ◽  
Juan Bueno-Pardo ◽  
Eliana A. Cordova ◽  
Joel M. Amisi ◽  
...  
Keyword(s):  
Deep Sea ◽  
Ne Atlantic ◽  
Bottom Trawling

scholarly journals Impacts of bottom trawling on benthic trophic status and meiofauna in a deep-sea sedimentary environment (Gulf of Castellammare, southwestern Mediterranean Sea)

2020 ◽  
Author(s):  
Antonio Pusceddu ◽  
Sarah Paradis ◽  
Davide Moccia ◽  
Pere Puig ◽  
Pere Masque ◽  
...  
Keyword(s):  
Community Composition ◽  
Deep Sea ◽  
Biochemical Composition ◽  
Benthic Communities ◽  
Sedimentary Environment ◽  
Sediment Cores ◽  
Organic Detritus ◽  
Bottom Trawling ◽  
Sedimentary Environments ◽  
The Impact

<p>The impacts of bottom trawling on the structure of benthic communities can be relatively non-selective, hitting biodiversity as a whole. This holds true also in the deep sea, where the impacts of trawling can be more severe and long-lasting than in shallow-waters, due to the reduced capacity for recovery and greater vulnerability of deep-sea organisms. For years, our knowledge of the impact of trawling on deep-water ecosystems has remained limited and has focused mainly on fish stocks and hard bottom systems. More recently, a number of studies have addressed the impacts of bottom trawling in the deep-sea sedimentary environments, and very few of them have focused on the impacts on meiofauna, though it is a key faunal component of deep-sea ecosystems.</p><p>We investigated the impact of bottom trawling on the quantity, biochemical composition and nutritional value of sedimentary organic matter and meiofauna along the Sicilian Margin (Gulf of Castellammare, southwestern Mediterranean) at ca. 550 m depth, during the summer of 2016. Amount, biochemical composition and freshness of sedimentary OM, as well as the abundance and community composition of meiofauna were determined in sediment cores taken at both trawled and untrawled grounds. The continuous erosive processes in the trawled site have led, generally, to the depletion of OM contents (20-60% lower than those in the untrawled site), as well as to statistically significant differences from the untrawled site in its biochemical composition. Nevertheless, the upper 2 cm of the trawled site consisted of recently accumulated sediments, enriched in phytopigments, and bulk OM contents similar to those in the untrawled one, interpreted as a very recent input of fresh OM from the upper water column. The abundance of meiofauna in trawled grounds was significantly higher than that in untrawled ones, whereas no differences were observed between trawled and untrawled grounds deeper in the sediment. Differences in the meiofaunal community composition among sediment layers in each site were larger than those among sites.</p><p>As previously reported, deep bottom trawling in the Gulf of Castellammare erodes large volumes of sediment, exposing old compacted sediment that is depleted in OM. This erosive action generally prevents the accumulation of fresh sediment. However, the episodic short-lived deposition of fresh organic detritus between hauls can lead to a temporary accumulation of fresh and bioavailable OM which, in turn, can induce a positive response in meiofauna abundance.</p><p>These results pinpoint the need of considering the impacts of bottom trawling on the benthic communities of deep-sea sedimentary environments at temporal scales shorter than previously done.</p>

scholarly journals Identifying the Value of Traditional Cultural Landscape in Rural Settlements

2021 ◽  
Vol 10 (1) ◽  
pp. 1-15
Author(s):  
Aslıhan Tırnakçı
Keyword(s):  
Cultural Values ◽  
Cultural Landscape ◽  
Climatic Factors ◽  
Regional Scale ◽  
Rural Landscape ◽  
Rural Settlements ◽  
Natural Landscape ◽  
Cultural Sustainability ◽  
Different Cultures ◽  
Very High

The traditions, socio-economic conditions, habitational settings and the climatic factors of a society become stratified with the cultural values ​​and establish the current values of the cultural landscape. The significance of a rural landscape as cultural heritage is directly related to the existence of cultural values and cultural landscape, which constitutes the totality of the cultural values ​​should be preserved in order to ensure historical and cultural sustainability. The study area (Şavşat/Artvin, Turkey) has a rich value based on its cultural landscape and texture, given its rich biodiversity and the lifestyle of different cultures that shaped the traditional settlement. Certain routes were determined within the scope of the present study, with the aim to encompass the whole Şavşat. A method based on an inventory study was employed to analyze the 39 rural settlements and the values of the traditional cultural landscape ​​were quantified through scoring 8 parameters based on the existence or nonexistence of cultural values. The 5-point scoring was ranged as follows: very low, low, medium, high and very high. Based on this scoring, Yavuz village, Kocabey, Kirazlı, Kayadibi, Çoraklı, Şavşat Center, Ilıca, Maden were found have high, Cevizli, Maden, Köprülü and Çağlayan were found to have very high values for the cultural landscape. Consequently, it was indicated that identifying the values of the traditional cultural landscape through the scoring system based on the existence and nonexistence of cultural values with respect to certain parameters could contribute to the literature. It was considered that the findings of the present study could provide an important database in the regional/sub-regional scale for the conservation of cultural values with natural landscape resources and conveying these values to future generations.

scholarly journals Trade-offs between environmental and economic factors in conversion from exotic pine production to natural regeneration on erosion prone land

2021 ◽  
Vol 51 ◽  
Author(s):  
Suzanne Lambie ◽  
Shaun Awatere ◽  
Adam Daigneault ◽  
Miko Kirschbaum ◽  
Michael Marden ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Forest Cover ◽  
Regional Scale ◽  
Cost Benefit ◽  
Native Forest ◽  
Limited Information ◽  
Honey Production ◽  
Trade Offs ◽  
Erosion Mitigation ◽  
Very High

Background: Some of New Zealand’s exotic pine (Pinus radiata D.Don) forests were planted for erosion mitigation but cultural, legislative, environmental, and profitability limitations in some parts of the landscape have led to reassessment of their suitability. There is limited information to support landowner decisions on the viability of natural regeneration of native forest post-pine-harvest. Methods: We evaluated scenarios of post-harvest natural regeneration, compared to remaining in pine production, using erosion susceptibility determined from historical occurrence of landslides, gullies and earthflows, biophysical growth modelling of mānuka–kānuka (Leptospermum scoparium-Kunzea ericoides (A.Rich) Joy Thomps.) shrubland using the process-based CenW model, and cost-benefit analyses using NZFARM with two land use change scenarios, at two levels of erosion mitigation ± honey profits. Results: In our study area, the Gisborne Region (North Island of New Zealand), ~27% of the land has moderate–very high susceptibility to landslides, 14–22% a high probability of contributing material to waterways, and 19% moderate–very high gully erosion susceptibility. Pines grow 10 times faster than naturally regenerating mānuka–kānuka shrubland, but mānuka–kānuka is used for honey not wood production. Natural regeneration resulted in losses of $150–250 ha-1 yr-1 compared to the current profitability of pine production. Honey production offset some reduction in pine revenue, but not fully. Thus, the viability of shifting from pines to native forest is highly dependent on landowner impetus and value for non-market ecosystem services (such as cultural and biodiversity values) provided by native forest. Conclusions: A mosaic of land uses within a property may sufficiently offset income losses with other benefits, whereby highly erosion-prone land is shifted from rotational pine forest production to permanent native forest cover with honey production where possible. At the regional scale in Gisborne, the conversion of the most highly susceptible land under production forestry (315–556 ha) to natural regeneration has the potential for wider benefits for soil conservation reducing erosion by 1–2.5 t yr–1 of sediment facilitating achievement of cleaner water aspirations and habitat provision.  

scholarly journals ECOLOGICAL RISK ASSESSMENT (ERA) APPLICATION FOR THE EVALUATION OF IMPACTS ON NATURAL AQUATIC ECOSYSTEMS

2019 ◽  
Vol 22 ◽  
Author(s):  
ÉRIC CESAR PAGLIARINI ◽  
VANESSA BEZERRA DE MENEZES OLIVEIRA ◽  
EVALDO LUIZ GAETA ESPINDOLA
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Aquatic Ecosystems ◽  
Advanced Degree ◽  
Physical Chemical ◽  
Systemic Impact ◽  
Very High ◽  
Degree Of Degradation ◽  
Lines Of Evidence

Abstract The present research employs the Ecological Risk Assessment (ERA) method to evaluate the probability of adverse effects in the water supply of Bom Repouso (MG), a city where the agriculture has caused an advanced degree of degradation of its sources. The methodology is based on the integration of different variables, divided into three Lines of Evidence (chemical, physical-chemical and ecotoxicological), and allows for the evaluation of risk assessment between 0.0 and 1.0 in the sampled environment. Five sampling points were evaluated in three periods, with the results varying between the four possible ratings (from low to very high), and it was not possible to identify a pattern of risk evolution between them. Thus, the method used proved to be efficient in assessing the degree of degradation of the environment, however, additional studies are required to improve this type of systemic impact assessment, based on the evaluation of the environmental degradation.

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