scholarly journals Preliminary results on the use of semi-floating shrimp traps for the striped soldier shrimp, Plesionika edwardsii (Crustacea: Decapoda: Pandalidae), off the Algarve coast (southern Portugal)

2018 ◽  
Vol 82 (S1) ◽  
pp. 209
Author(s):  
Moritz Eichert ◽  
Aida Campos ◽  
Paulo Fonseca ◽  
Victor Henriques ◽  
Margarida Castro
Keyword(s):  
Environmental Impact ◽  
Deep Water ◽  
Bottom Trawl ◽  
Marine Strategy Framework Directive ◽  
Precautionary Approach ◽  
Preliminary Results ◽  
Product Value ◽  
Fisheries Policy ◽  
Southern Portugal ◽  
Experimental Survey

The present study provides an account of an experimental survey aiming at the evaluation of the catchability of the striped soldier shrimp, Plesionika edwardsii, using semi-floating shrimp traps off the Algarve coast (southern Portugal). Currently, this species is not targeted by the crustacean bottom trawl fleet, and preliminary results on product value suggest that this may become an economically viable new fishery. Preliminary results suggest that this fishery could contribute to the diversification of fixed gears of low environmental impact targeting deep-water crustaceans, in agreement with the objectives of both the Marine Strategy Framework Directive and the reformed Common Fisheries Policy. However, potential spatial conflicts with trawling, the unknown size of the resource and a necessary precautionary approach may limit the number of licences that can be granted.

scholarly journals Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities

2010 ◽  
Vol 68 (2) ◽  
pp. 319-332 ◽  
Author(s):  
F. J. Murillo ◽  
P. Durán Muñoz ◽  
A. Altuna ◽  
A. Serrano
Keyword(s):  
Atlantic Ocean ◽  
Continental Slope ◽  
Deep Water ◽  
Coral Species ◽  
Habitat Mapping ◽  
Bottom Trawl ◽  
Soft Corals ◽  
Northwest Atlantic ◽  
Grand Banks ◽  
Black Corals

Abstract Murillo, F. J., Durán Muñoz, P., Altuna, A., and Serrano, A. 2011. Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities. – ICES Journal of Marine Science, 68: 319–332. The distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland is described based on bycatch from Spanish/EU bottom trawl groundfish surveys between 40 and 1500 m depth. In all, 37 taxa of deep-water corals were identified in the study area: 21 alcyonaceans (including the gorgonians), 11 pennatulaceans, 2 solitary scleractinians, and 3 antipatharians. The greatest diversity of coral species was on the Flemish Cap. Corals were most abundant along the continental slope, between 600 and 1300 m depth. Soft corals (alcyonaceans), sea fans (gorgonians), and black corals (antipatharians) were most common on bedrock or gravel, whereas sea pens (pennatulaceans) and cup corals (solitary scleractinians) were found primarily on mud. The biomass of deep-water corals in the bycatches was highest in previously lightly trawled or untrawled areas, and generally low in the regularly fished grounds. The information derived from bottom-trawl bycatch records is not sufficient to map vulnerable marine ecosystems (VMEs) accurately, but pending more detailed habitat mapping, it provides a valuable indication of the presence/absence of VMEs that can be used to propose the candidate areas for bottom fishery closures or other conservation measures.

scholarly journals Limited mid-water scavenging of trawl discards

2003 ◽  
Vol 83 (4) ◽  
pp. 731-734 ◽  
Author(s):  
Karim Erzini ◽  
Pedro Monteiro ◽  
Artur Araújo ◽  
Margarida Castro
Keyword(s):  
Water Column ◽  
Deep Water ◽  
Small Fish ◽  
Sea Birds ◽  
Trawl Fishing ◽  
Southern Portugal ◽  
Catch Rates ◽  
Electric Fishing ◽  
Scavenging Rates

The consumption or scavenging of fish in the water column at depths from 75 to 275 m in Algarve (southern Portugal) trawl fishing grounds was evaluated. Longlines were used to suspend baits throughout the water column while electric fishing reels were used to simulate sinking discards. Eighteen species were caught, with higher catch rates near the surface than near the bottom. However, scavenging rates were generally highest near the bottom and lowest in the middle of the water column. At depths less than 100 m the majority or all the fish were scavenged throughout the water column, while at depths greater than 200 m most of the fish were untouched after periods of time greater than would be required for them to sink to the bottom. Since other studies have shown that most small fish discards are scavenged at the surface by sea birds and most of the discarded species that sink are either too large or not attractive to pelagic predators, these results suggest that mid-water scavenging of trawl discards in deep water is relatively unimportant.

scholarly journals length at first maturity of two species of lantern sharks (etmopterus spinax and etmopterus pusillus) off southern portugal

2005 ◽  
Vol 85 (5) ◽  
pp. 1163-1165 ◽  
Author(s):  
rui coelho ◽  
karim erzini
Keyword(s):  
Deep Water ◽  
Shark Species ◽  
Fishing Mortality ◽  
Portuguese Coast ◽  
Southern Portugal ◽  
First Maturity ◽  
Late Maturation ◽  
Size At First Maturity

etmopterus spinax and etmopterus pusillus are captured in large quantities in some deep-water fisheries along the portuguese coast and are always discarded. specimens were collected from february 2003 to may 2004 from deep-water fisheries and classified as mature or immature. maturity ogives were fitted and size at first maturity estimated for each sex of each species. both species are late maturing, with the maturity sizes varying between 75% and 87% of the maximum observed sizes, depending on species and sex. for both species, females tended to mature at and grow to larger sizes than males. the late maturation of these deep-water shark species makes these populations extremely vulnerable to increasing fishing mortality.

Feeding habits of the velvet belly lanternshark Etmopterus spinax (Chondrichthyes: Etmopteridae) off the Algarve, southern Portugal

2006 ◽  
Vol 86 (4) ◽  
pp. 835-841 ◽  
Author(s):  
João Neiva ◽  
Rui Coelho ◽  
Karim Erzini
Keyword(s):  
Deep Water ◽  
Foraging Behaviour ◽  
Prey Size ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Prey Composition ◽  
Southern Portugal ◽  
Meganyctiphanes Norvegica ◽  
Diet Shifts

Etmopterus spinax is one of the most abundant predators of the upper continental slope off the Algarve (southern Portugal), where it is captured in large quantities in deep-water fisheries. The feeding habits of E. spinax off the Algarve were investigated through the analysis of stomach contents of 376 individuals. Prey composition was described and maturity, sex and size related variations in the diet analysed. The overall diet of E. spinax suggested a fairly generalized benthopelagic foraging behaviour primarily tuned to pelagic macroplankton/microneckton, teleost fish and cephalopods. Sex and maturity related differences in the diet were not significant. Two main ontogenic diet shifts were observed at about 17 and 28 cm total length. Small and medium sized immature sharks had a diet dominated by eurybathic crustaceans, chiefly Meganyctiphanes norvegica and Pasiphaea sivado. Larger individuals consumed more teleosts and cephalopods, in part associated with scavenging as a new feeding strategy. With increasing shark size the diet diversified both in terms of resources exploited and prey size.

MODELING DEEPWATER OIL SPILLS WITH NEAR FIELD AND FAR FIELD MODELS

2005 ◽  
Vol 2005 (1) ◽  
pp. 725-730
Author(s):  
Zhen-Gang Ji ◽  
Walter R. Johnson ◽  
Charles F. Marshall ◽  
James M. Price
Keyword(s):  
Environmental Impact ◽  
Gulf Of Mexico ◽  
Deep Water ◽  
Oil And Gas ◽  
Field Model ◽  
Oil Spills ◽  
Near Field ◽  
Far Field ◽  
Oil Gas ◽  
The U.S

ABSTRACT As a Federal agency within the U.S. Department of the Interior (DOI), the Minerals Management Service (MMS) maintains a leasing program for commercial oil and gas development on the U.S. Outer Continental Shelf (OCS). Oil and gas activities in deep water (areas deeper than 340 meters) have proceeded at an unprecedented rate, and have led to concerns regarding the accidental release of oil near the seafloor. As production increases, the potential for an oil/gas spill increases. In addition to the environmental impacts of the oil spilled, major concerns from a deepwater oil/gas spill include fire, toxic hazard to the people working on the surface installations, and loss of buoyancy by ships and any floating installations. Oil and natural gas releases in deep water behave much differently than in shallow water, primarily due to density stratification, high pressures, and low temperatures. It is important to know whether oil will surface and if so, where, when, and how thick the oil slick will be. To meet these new challenges, spill response plans need to be upgraded. An important component of such a plan would be a model to simulate the behavior of oil and gasses accidentally released in deep water. This has significant implications for environmental impact assessment, oil-spill cleanup, contingency planning, and source tracing. The MMS uses the Clarkson Deepwater Oil and Gas Blowout (CDOG) plume model to simulate the behavior of oil and gas accidentally released in deepwater areas. The CDOG model is a near field model. In addition, MMS uses an adaptation of the Princeton Ocean Model called the Princeton Regional Ocean Forecast and Hindcast System for the Gulf of Mexico (PROFS-GOM). This model is a far field model and is employed to provide three dimensional current, temperature, and salinity data to the CDOG model. The PROFS-GOM model and the CDOG model are used to simulate deepwater oil spills in the Gulf of Mexico. Modeling results indicate that the two models can provide important information on the behavior of oil spills in deepwater and assist MMS in estimating the associated environmental risks. Ultimately, this information will be used in the pertinent environmental impact assessments MMS performs and in the development of deepwater oil-spill response plans.

scholarly journals Can a square-mesh panel inserted in front of the cod end improve size and species selectivity in Mediterranean trawl fisheries?

2018 ◽  
Vol 75 (5) ◽  
pp. 704-713 ◽  
Author(s):  
Jure Brčić ◽  
Bent Herrmann ◽  
Antonello Sala
Keyword(s):  
Deep Water ◽  
Bottom Trawl ◽  
Horse Mackerel ◽  
Trachurus Trachurus ◽  
Merluccius Merluccius ◽  
Low Probability ◽  
Low Efficiency ◽  
Trawl Fisheries ◽  
European Hake ◽  
Atlantic Horse Mackerel

An experiment was conducted to assess the selectivity in a typical Mediterranean bottom trawl, equipped with a square-mesh panel inserted in front of the cod end, for Atlantic horse mackerel (Trachurus trachurus), European hake (Merluccius merluccius), red mullet (Mullus barbatus), poor cod (Trisopterus minutus), broadtail shortfin squid (Illex coindetii), and deep-water rose shrimp (Parapaeneus longirostris). The release efficiency of undersized individuals through the panel was low. The differences in selectivity between the gear with and without the panel were very small. The low release efficiency of the square-mesh panel was caused by the lack of fish contact with the panel as they drifted towards the cod end, since the average contact probability was estimated not to exceed 9% for any of the species investigated. A low probability of contact with the selection device was thus found to be the reason for the low efficiency of the square-mesh panel.

Fractal Shape Analysis of Tire Debris Particles: Preliminary Results and Applications

2000 ◽  
Vol 661 ◽  
Author(s):  
Marina Camatini ◽  
Giovanni F Crosta ◽  
Gaia M Corbetta ◽  
Mara Ottin-Bocat ◽  
Stefano Ambrosio ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Environmental Impact ◽  
Light Microscopy ◽  
Shape Analysis ◽  
Processing Parameters ◽  
Conditional Probabilities ◽  
Preliminary Results ◽  
Debris Particles ◽  
Tread Rubber ◽  
Wear Tests

ABSTRACTParticles of tread rubber debris produced by laboratory wear tests are imaged by light microscopy. The fractal dimension, DF, of the image perimeter is estimated. The sensitivity of DF with respect to the image acquisition and processing parameters is determined. Particles belonging to two types of undifferentiated debris, low severity (LS) and rasping (R), respectively, are analyzed. The values of DF have distributions, which, if suitably interpreted, allow the identification of either debris type with the following conditional probabilities: pLS|LS = 0.71 and pR|R = 0.81. The procedure can be eventually applied to environmental impact studies.

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