Effects of anti-trawling artificial reefs on ecological indicators of inner shelf fish and invertebrate communities in the Cantabrian Sea (southern Bay of Biscay)

2010 ◽  
Vol 91 (3) ◽  
pp. 623-633 ◽  
Author(s):  
Alberto Serrano ◽  
Cristina Rodríguez-Cabello ◽  
Francisco Sánchez ◽  
Francisco Velasco ◽  
Ignacio Olaso ◽  
...  
Keyword(s):  
Sea Urchins ◽  
Recovery Period ◽  
Total Biomass ◽  
Shelf Area ◽  
Inner Shelf ◽  
Generalist Species ◽  
Stock Biomass ◽  
Key Factor ◽  
Total Stock ◽  
Zeus Faber

The analyses presented in this paper provide evidence that several community metrics and indicators of the inner shelf community in the Cantabrian Sea show response to placement of anti-trawling reefs. Total biomass, species richness, and to a lesser extent, maximum length and percentage of large fish, were sensitive to exclusion of trawling. Density, diversity and average trophic level did not show this sensitivity. The main species profiting from trawl exclusion were seabreams (Sparidae), catsharks and skates (Elasmobranchii), red mullets (Mullidae), gurnards (Triglidae) and John Dory (Zeus faber). Conversely, the main fishery target species (hake, anglerfish and megrim) showed a progressive decrease in abundance during the study period, a pattern which was also shown by their total stock biomass in the totality of the shelf area. Sea urchins, cephalopods and gastropods also increased in relative abundance with trawl exclusion. Reef age was identified as a key factor in reef development. After reef deployments, two periods were identified: (1) a recovery period, in which total biomass increased, mainly as a consequence of the increase in generalist species (e.g. catsharks); and (2) a consolidation period, during which biomass increased again, mainly as a consequence of an increase in specialized stenoic species (e.g. sparids), while biomass of generalist species remained constant or declined.

scholarly journals Farm practices as they affect NH3 emissions from beef cattle

2012 ◽  
Vol 92 (4) ◽  
pp. 525-543 ◽  
Author(s):  
S. C. Sheppard ◽  
S. Bittman
Keyword(s):  
Beef Cattle ◽  
Best Management Practices ◽  
Management Practices ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Total Biomass ◽  
The West ◽  
Finishing Cattle ◽  
Key Factor ◽  
Using Data

Sheppard, S. C. and Bittman, S. 2012. Farm practices as they affect NH 3 emissions from beef cattle. Can. J. Anim. Sci. 92: 525–543. Beef cattle farms in Canada are very diverse, both in size and management. Because the total biomass of beef cattle in Canada is larger than any other livestock sector, beef also has the potential for the largest environmental impact. In this study we estimate NH3 emissions associated with beef cattle production across Canada using data on farm practices obtained from a detailed survey answered by 1380 beef farmers in 11 Ecoregions. The farms were various combinations of cow/calf, backgrounding and finishing operations. The proportion of animals on pasture varied markedly among Ecoregions, especially for cows and calves, and this markedly affected the estimated NH3 emissions. The crop components of feed also varied among Ecoregions, but the resulting crude protein concentrations were quite consistent for both backgrounding and finishing cattle. Manure was stored longer in the west than in the east, and fall spreading of manure was notably more common in the west, especially when spread on tilled land. The estimated NH3 emissions per animal were relatively consistent across Ecoregions for confinement production, but because the proportion of animals on pasture varied with Ecoregion, so did the overall estimated NH3 emissions per animal. Temperature is a key factor causing Ecoregion differences, although husbandry and manure management practices are also important. Hypothetical best management practices had little ability to reduce overall emission estimates, and could not be implemented without detailed cost/benefit analysis.

Isotopic, trace element and nutrient characterization of coastal waters from Ubatuba inner shelf area, south-eastern Brazil

2008 ◽  
Vol 76 (3) ◽  
pp. 522-542 ◽  
Author(s):  
P.P. Povinec ◽  
J. de Oliveira ◽  
E.S. Braga ◽  
J.-F. Comanducci ◽  
J. Gastaud ◽  
...  
Keyword(s):  
Trace Element ◽  
Coastal Waters ◽  
Shelf Area ◽  
Inner Shelf ◽  
South Eastern ◽  
Eastern Brazil

Indices of Total Stock Biomass in the "Northern" and Gulf of St. Lawrence Atlantic Cod (Gadus morhua) Stocks Derived from Time Series Analyses of Fixed Gear (Trap) Catches

1992 ◽  
Vol 49 (2) ◽  
pp. 202-209 ◽  
Author(s):  
G. A. Rose
Keyword(s):  
Time Series ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Moving Average ◽  
Stock Biomass ◽  
Northern Cod ◽  
Cross Correlations ◽  
Time Series Analyses ◽  
Trap Catches ◽  
Total Stock

The hypothesis that annual catches of fixed gear fisheries are cross-correlated with stock biomass at lags predictable on the basis of the relative ages of fish comprising the catch and biomass was verified for the trapnet fisheries of the northeastern Newfoundland "northern" (NAFO 2J3KL) and northern "Gulf" of St. Lawrence (NAFO 3Pn4RS) Atlantic cod (Gadus morhua) stocks. Time series indices of stock biomass were derived from these cross-correlations. For northern cod, the index was a 3-yr weighted and lagged moving average of catch. For the years 1972–81 (the first half of the available data) the trap index (Ti) was regressed on the stock biomass (Bi) determined by sequential population models (SPA) (Ti = 0.477Bi0.638, r = 0.99, P < 0.01). Biomass forecasts for 1982–90 derived from this function (inverted) were positively correlated with recent SPA-based estimates (r = 0.94, P < 0.02). For Gulf cod, the index was a 4-yr weighted and lagged moving average of catch. This index was regressed on SPA-determined biomass for the years 1974–81 (Ti = −3.19 + 0.0217Bi, r = 0.99; P < 0.01). Biomass forecasts for 1982–90 were positively correlated with (but lower than) SPA-based biomass estimates for the Gulf stock (r = 0.91, P < 0.05).

The near future of coral reefs

2002 ◽  
Vol 29 (4) ◽  
pp. 460-483 ◽  
Author(s):  
Timothy R. McClanahan
Keyword(s):  
Coral Reefs ◽  
Sea Urchins ◽  
Trophic Levels ◽  
Current Status ◽  
Toxic Substances ◽  
Atmospheric Concentration ◽  
Seawater Chemistry ◽  
Generalist Species ◽  
The Past ◽  
Use Of Resources

In this paper the current status of coral reefs, predictions concerning the ecological state of coral reefs to the 2025 time horizon and the research needs that can help understanding and management activities that might alleviate detrimental ecological changes are evaluated and discussed. The present rate of CO2 emissions will produce an atmospheric concentration in 100 years not experienced during the past 20 million years and water temperatures above those of the past interglacial 130 000 years before present. Human influences on water temperatures, seawater chemistry (toxic substances, nutrients and aragonite saturation), the spread of diseases, removal of species and food web alterations are presently changing reef ecology. A significant ecological reorganization is underway and changes include a reduction in calcifying and zooxanthellae-hosting organisms, their obligate symbionts, and species at higher trophic levels, with an increase in generalist species of low trophic level that are adapted to variable environments. Late-successional fleshy brown algae of low net productivity or non-commercial invertebrates such as sea urchins, starfish and coral-eating snails will dominate many reefs. These changes will be associated with a loss of both net benthic and fisheries production and inorganic carbonate deposition; this will reduce reef complexity, species richness, reef growth and increase shoreline erosion. To avert these changes management is needed at both global and local levels. Both levels need to reduce greenhouse gases and other waste emissions and renew efforts to improve resource management including restrictions on the use of resources and globalization of resource trade, run-off and waste production, and balancing potential reef production and resource consumption.

scholarly journals Unlocking the secrets of mutable collagenous tissue

2018 ◽  
Vol 40 (1) ◽  
pp. 8-11
Author(s):  
Himadri S. Gupta ◽  
Greg Szulgit ◽  
Maurice R. Elphick ◽  
Jingyi Mo
Keyword(s):  
Real Time ◽  
Conformational Changes ◽  
Molecular Level ◽  
Sea Urchins ◽  
Collagen Fibrils ◽  
Sea Cucumbers ◽  
X Ray ◽  
Collagenous Tissue ◽  
Key Factor ◽  
Shed Light

The mutable collagenous tissue (MCT) of echinoderms (e.g. sea cucumbers, starfish and sea urchins) is unique because of its ability to ‘switch’ mechanical states rapidly and reversibly – from stiff to soft and vice versa. This kind of tissue in humans, for example, in skin, tendons and ligaments, does not have this property. So what are the molecular-level secrets by which MCT achieves this transformative ability? New real-time ultrastructural investigations are beginning to shed light on this question. Synchrotron X-ray measurements of dynamic molecular conformational changes point to the key factor being the gel-like matrix between the collagen fibrils. These findings could have applications for developing treatments for collagen-based disorders.

scholarly journals Some features of the pale sea urchin (Strongylocentrotus pallidus) biology in Peter the Great Bay (Japan Sea)

2017 ◽  
Vol 188 (1) ◽  
pp. 140-154
Author(s):  
Maria O. Chalienko ◽  
Marianna V. Kalinina
Keyword(s):  
Continental Slope ◽  
Sea Urchin ◽  
Size Structure ◽  
Sea Urchins ◽  
Peter The Great Bay ◽  
Maturity Stage ◽  
Shelf Area ◽  
Peter The Great ◽  
Great Bay ◽  
Average Size

Population of pale sea urchin Strongylocentrotus pallidus in Peter the Great Bay is investigated. The samples for its size structure and distribution were collected at the depth from 5 to 700 m in July 2013, 2014 and in April 2015 and the samples for the state of gonads, intestines and age structure - at the depths of 41, 69, 280, 346, and 670 m in early April 2015. The size structure at different depths is significantly different: the large individuals with average size of 70.0 mm (portion of commercial ones 98 %) occupy mainly the middle shelf area with the depths of 55-100 m, deeper at the depths of 100-200 m the portion of commercial urchins is lower (67 % in 2014 and 92 % in 2015), and the continental slope (depth > 200 m) is occupied by mainly (77-96 %) non-commercial individuals with average size of 35.5 mm. Age of sea urchins was determined by the growth zones on plates of their shells processed by Jensen method and varied from 3 to 12 years. The growth rate of sea urchins from the shelf areas was approximately in 1.5 times higher as compared with those from the continental slope, primarily due to different conditions of feeding. The gonads cellular composition was defined for the samples of 50 cells per female. The cells were differentiated in the categories of oocytes proliferation, oocytes differentiation, and mature eggs, and the gonad maturity stage was determined by domination of these categories, taking into accounts the S. pallidus reproductive cycle. In spring, the sea urchins from the shelf areas (depths of 41 and 69 m) were generally more mature as compared with those from the continental slope (depths of 280 and 346 m). However, correlation between the gonadal index and depth of habitat was not significant because the mature females were sampled in any depth. Composition of intestinal content and food components were determined visually, looking the bolus under binocular microscope. The sea urchins intestines were mostly filled with detritus at the depth of 41 m, sponges (Suberites sp.) at the depth of 69 m (70 % of cases), and unedible substances as silt and sand at the depth of 280, 346 and 670 m, minor fractions were the algal litter, remains of crustaceans, and detritus.

Modeling and Biomass Quantification in Eucalyptus saligna Smith Stand at the End Rotation in the South of Brazil

2019 ◽  
pp. 1-10
Author(s):  
Dione Richer Momolli ◽  
Mauro Valdir Schumacher ◽  
Aline Aparecida Ludvichak ◽  
Elias Frank Araújo
Keyword(s):  
Form Factor ◽  
Total Biomass ◽  
Rio Grande Do Sul ◽  
Eucalyptus Saligna ◽  
Stock Biomass ◽  
The Mean ◽  
South Of Brazil ◽  
Biomass Quantification ◽  
Selection Of

The quantification of wood stock and other components of biomass is fundamental for forest planning. Given the difficulty of obtaining these data, the present study aims at the formulation of equations and the estimation of the different components of biomass, volume with and without bark, form factor and height of the trees at the end rotation. The study was carried out in the municipality of São Gabriel state of Rio Grande do Sul, Brazil with Eucalyptus saligna 10-year-old. The experimental design of the inventory and biomass quantification were completely randomized. In the inventory the DBH of all individuals of the 5 plots were measured. After determination of 4 classes of diameter were felled 12 trees and quantified leaves, branches, bark and wood. The selection of the models obtained coefficients of determination higher than 97%. The total biomass was 269 Mg ha-1, of which 89% was wood. The total volume was 546 and 494 m³ ha-1 with and without bark, representing an average annual increase of 54,6 and 49,4 m³ ha-1 year-1. The mean form factor was 0,48. The modeling presented excellent adjustments and certainly serves for future estimates of the stock biomass.

scholarly journals Cross-Shelf Differences in the Response of Herbivorous Fish Assemblages to Severe Environmental Disturbances

Diversity ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 23 ◽  
Author(s):  
Eva McClure ◽  
Laura Richardson ◽  
Alexia Graba-Landry ◽  
Zoe Loffler ◽  
Garry Russ ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Coral Cover ◽  
Herbivorous Fish ◽  
Total Biomass ◽  
Hard Coral ◽  
Inner Shelf ◽  
Environmental Disturbances ◽  
Local Conditions ◽  
Thermal Bleaching ◽  
Hard Coral Cover

Cross-shelf differences in coral reef benthic and fish assemblages are common, yet it is unknown whether these assemblages respond uniformly to environmental disturbances or whether local conditions result in differential responses of assemblages at different shelf positions. Here, we compare changes in the taxonomic and functional composition, and associated traits, of herbivorous reef fish assemblages across a continental shelf, five years before and six months after two severe cyclones and a thermal bleaching event that resulted in substantial and widespread loss of live hard coral cover. Each shelf position maintained a distinct taxonomic assemblage of fishes after disturbances, but the assemblages shared fewer species among shelf positions. There was a substantial loss of species richness following disturbances within each shelf position. Total biomass of the herbivorous fish assemblage increased after disturbances on mid- and outer-shelf reefs, but not on inner-shelf reefs. Using trait-based analyses, we found there was a loss of trait richness at each shelf position, but trait specialisation and originality increased on inner-shelf reefs. This study highlights the pervasiveness of extreme environmental disturbances on ecological assemblages. Whilst distinct cross-shelf assemblages can remain following environmental disturbances, assemblages have reduced richness and are potentially more vulnerable to chronic localised stresses.

scholarly journals Organochlorine pesticides residues and PCBs in benthic organisms of the inner shelf of the São Sebastião Channel, São Paulo, Brazil

2004 ◽  
Vol 52 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Rosângela Gorni ◽  
Rolf Roland Weber
Keyword(s):  
Pesticide Residues ◽  
Feeding Habits ◽  
Human Consumption ◽  
Shelf Area ◽  
Benthic Organisms ◽  
Inner Shelf ◽  
Industrial Activities ◽  
Pesticides Residues ◽  
Marine Areas ◽  
Land Runoff

Thirty seven benthic samples of the inner shelf area of São Sebastião, Brazil, were collected between April 1994 and August 1998 and analysed for seventeen chlorinated pesticide residues and PCBs congeners. Pesticide residues and PCBs congeners levels were low (ng/g) and predominantly found in the crustacean samples. DDE was the most frequently residue with a maximum of 9,7 ng/g followed by HCHs with maximum of 17,1ng/g. As for the PCBs, the heavier congeners predominate: CB 138,153,170, 180 and 183. Maximum total PCBs was 17,4 ug/g in a crab sample. Higher levels of PCBs are related to feeding habits and local inputs of raw sewage or land runoff. Although EPA and FDA (U.S.A) below the guidelines for human consumption propose these levels, they do show that even in marine areas without intense agricultural or industrial activities these compounds are present at detectable levels.

scholarly journals Genetic architecture of pollination syndrome transition between hummingbird-specialist and generalist species in the genus Rhytidophyllum (Gesneriaceae)

2015 ◽  
Author(s):  
Hermine Alexandre ◽  
Justine Vrignaud ◽  
Brigitte Mangin ◽  
Simon Joly
Keyword(s):  
Genetic Architecture ◽  
Genetic Basis ◽  
Pollination Syndrome ◽  
Pollination Syndromes ◽  
Generalist Species ◽  
Nectar Volume ◽  
Key Factor ◽  
The Caribbean ◽  
Specialist Species ◽  
Floral Characters

Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.

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