Instituto Nacional Of Recursos Biologicos Inrb

Olhão, Portugal

Instituto Nacional Of Recursos Biologicos Inrb

Olhão, Portugal
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Vasconcelos P.,Instituto Nacional Of Recursos Biologicos Inrb | Gaspar M.B.,Instituto Nacional Of Recursos Biologicos Inrb
Journal of Environmental Monitoring | Year: 2010

The present study aimed at creating a so called "single-site baseline" (SSB) of imposex in the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (Algarve coast, southern Portugal), at the moment that the IMO Antifouling System Convention (banning globally the use of organotin compounds in antifouling paints on ships' hulls) entered into force (September 2008). In the context of monitoring long-term temporal trends of pollution levels, SSBs are proposed whenever it is difficult to obtain adequate numbers of bioindicator specimens in most of the study area or if significant short-term variability in imposex levels is likely to occur. In order to deal with these constraints, this study created a SSB by sampling on a monthly-basis (from October 2008 to September 2009) in a single site considered to be representative of the Ria Formosa as a whole (vicinities of the Culatra Island) and where B. brandaris is abundant all year round. The SSB provided a good characterisation of the monthly variation in the imposex indices, which ranged throughout the year between 72.7 < I% < 100; 0.08 < FPLI < 1.73; 1.20 < RPLI < 23.27; 1.29 < VDSI < 3.54. Only a SSB could have detected this large variability, which otherwise might have been unnoticed and would have produced biased temporal and spatial comparisons, leading to erroneous interpretations of environmental monitoring data. Therefore, this SSB of imposex in B. brandaris constitutes valuable reference data to assess the future trend of organotin pollution in the Ria Formosa, after the benchmark date of the complete eradication of organotin from antifouling agents was implemented worldwide. © 2010 The Royal Society of Chemistry.

Vasconcelos P.,Instituto Nacional Of Recursos Biologicos Inrb | Morgado-Andre A.,University of Algarve | Morgado-Andre C.,University of Algarve | Gaspar M.B.,Instituto Nacional Of Recursos Biologicos Inrb
ICES Journal of Marine Science | Year: 2011

The smooth clam Callista chione is exploited by a fleet of dredgers along the southwestern coast of Portugal and suffers from a high incidence of shell damage. The force required to break C. chione shells in relation to fishing impacts and dredge damage is quantified. Fishing trials and shell-strength measurements (compression and compaction experiments) were performed to determine whether shell damage was attributable to the direct impact of the dredge teeth or to sediment compaction. A three-dimensional model of C. chione was subjected to simulated force by the finite element method. Analyses of damage areas and breakage patterns revealed two groups of samples, one containing the samples from compression experiments and another with the samples from dredging and compaction experiments, suggesting that most shell damage was attributable to compaction within the sediment. Information is provided to help improve the design of bivalve dredges, by increasing both length and angle of the dredge teeth, which would reduce the compaction force and distribute it differentially within the sediment, forcing upward movement of the bivalves. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.

de Sousa J.T.,Instituto Nacional Of Recursos Biologicos Inrb | Joaquim S.,Instituto Nacional Of Recursos Biologicos Inrb | Matias D.,Instituto Nacional Of Recursos Biologicos Inrb | Ben-Hamadou R.,University of Algarve | Leitao A.,Instituto Nacional Of Recursos Biologicos Inrb
Aquaculture | Year: 2012

Aneuploidy is a cytogenetic phenomenon known as an abnormal diploid chromosome number. A negative relationship between growth rate, one of the biggest problems faced by bivalve producers, and this phenomenon was already verified for two oyster species, the Japanese oyster Crassostrea gigas, the Portuguese oyster Crassostrea angulata and their interspecific hybrids and, more recently, in the carpet shell clam Ruditapes decussatus. The main objective of this study was to assess whether chromosome losses in aneuploid situations could be explained by differential chromosomal susceptibility, as previously reported in the oyster C. gigas. Thereby, we applied the restriction enzyme (RE) digestion chromosome banding technique to aneuploid karyotypes of R. decussatus and C. angulata, in order to identify the missing chromosomes. The results of this study showed that 4 out of the 19 chromosome pairs (viz. 1, 6, 12, and 19) of R. decussatus and 3 out of the 10 chromosome pairs (viz. 1, 9, and 10) of C. angulata were preferentially affected by the loss of one homologous chromosome. The chromosomal loss in C. angulata was very similar to the one previously observed in C. gigas. These results open a new field for further research in order to have a better understanding of the aneuploidy phenomenon in bivalves and particularly its negative relationship with growth rate. © 2012 Elsevier B.V..

Tzanatos E.,University of Patras | Castro J.,Spanish Institute of Oceanography | Forcada A.,University of Alicante | Matic-Skoko S.,Croatian Institute Of Oceanography And Fisheries | And 2 more authors.
ICES Journal of Marine Science | Year: 2013

The present work presents an integrated comparative assessment of the sustainability of fishing tactics or métiers (combinations of area, season, fishing gear, and target species). An index, which includes biological, conservation, socioeconomic, and management criteria, was created for this purpose: the "Métier Sustainability Index" (MSI25). It was designed using the traffic lights approach and comprises 25 indicators that refer to the "health" of the fisheries. Additionally, the MSI25 provides an indication of the "certainty" of that information with regard to the data type/heterogeneity. Subsequently, the index was tested using data from six case studies (81 métiers) from the Mediterranean and the Atlantic. The index showed that 63.0% of the métiers were "sustainable", 21.0% were "unsustainable" and 16.0% were "under pressure"; 59.3% of characterizations were considered as "certain". The index evaluation showed significant differences between areas and gears. This paper considers the characteristics of the datasets used, the case management status, and the applicability of the index in improving the management of specific fisheries. Overall, the MSI25 was found to be a useful tool for the evaluation and management of highly heterogeneous fisheries and data from various sources and types. © 2012 International Council for the Exploration of the Sea.

Matos E.,University of Algarve | Goncalves A.,Instituto Nacional Of Recursos Biologicos Inrb | Nunes M.L.,Instituto Nacional Of Recursos Biologicos Inrb | Dinis M.T.,University of Algarve | Dias J.,University of Algarve
Aquaculture | Year: 2010

The aim of this study was to assess the independent effects of harvesting stress and slaughter method on seabream flesh quality. Two groups of 32 gilthead seabream (mean body weight: 536 ± 96 g) were subjected to different pre-slaughter harvesting stress: profound anesthesia (PA, low stress condition) and net crowding (NC, high stress condition). Subsequently, fish from both harvesting stress conditions were slaughtered using either ice-salt water slurry (IW), to simulate commercial practices, or a lethal dose of anesthesia (LA), to isolate the effect of the pre-slaughter treatments. Rigor mortis was measured during the first 72 h after death, and muscle from the dorsal area was collected at regular intervals (0, 2, 6 and 48 h after death) during this period, for subsequent biochemical analysis of pH, TBARS, sulfated glycosaminoglycans and hydroxyproline content. Texture in raw and cooked fillets was measured instrumentally, using an Instron texture analyzer. The onset of rigor mortis was earliest for the NC-IW treatment, reaching highest values 2 h after death, while fish from the PA-IW treatment attained highest rigor scores 21 h after death. Resolution of rigor mortis started 3 and 32 h after death in fish subjected to NC and PA, respectively. Both harvesting stress and slaughter method had a significant effect (P< 0.05) on muscle pH, with highest values found in fish subjected to PA conditions, and in those slaughtered by lethal anesthesia. Muscle TBARS were significantly affected by harvesting stress. Collagen and sulfated glycosaminoglycan content of the samples decreased markedly through storage time, but were not significantly affected by harvesting stress conditions or slaughter method. In fish slaughtered in ice-salt water slurry, fillet hardness ranged between 5.0 ± 2.1 and 5.7 ± 1.8. N in raw fillets, and between 4.9 ± 0.9 and 5.6 ± 0.9. N in cooked fillets, but no significant differences among treatments were found. The use of zero withdrawal anesthetic improved muscle pH and delayed rigor mortis, although harvesting and slaughter stress had no major effect on muscle structure of gilthead seabream. © 2010 Elsevier B.V.

Gharsallah I.H.,Institute National Des Science Et Technologies Of La Mer Instm | Vasconcelos P.,Instituto Nacional Of Recursos Biologicos Inrb | Zamouri-Langar N.,Institute National Des Science Et Technologies Of La Mer Instm | Missaoui H.,Direction Generale de la Peche et de lAquaculture DGPA
Aquatic Biology | Year: 2010

This study investigates the reproductive cycle, size at first sexual maturity and biochemical composition of Hexaplex trunculus from the Bizerte lagoon (northern Tunisia). Overall, females predominated over males, resulting in an unbalanced sex ratio of 1.2:1. Males dominated in the smaller size classes (<40 mm shell length, SL), sex ratios were balanced at the 40 to 50 mm SL range, and females dominated in the larger size classes (>50 mm SL). The gonad developmental stages and the gonadosomatic index (GSI) indicated that H. trunculus apparently has an annual reproductive cycle with extended periods of gonadal activity. In both sexes, examination of the appearance of the gonads showed that gamete release occurred mainly from March to May (with an apparent spawning between March and April), followed by a period of empty gonads between June and August. Sexual maturity occurred at smaller sizes in males (SL50 = 41.02 mm SL) than in females (SL50 = 50.47 mm SL). The contents of protein, lipids and carbohydrates were invariably greater in the gonads than in the foot, confirming the key role of the reproductive tissues in energetic storage. The monthly variation in protein, lipids and carbohydrates in the gonads followed the oscillation in the relative proportion of developed gonads and in the GSI, reflecting energetic mobilisation during maturation and spawning. Overall, the data gathered in this study constitutes valuable baseline information for making preliminary recommendations to the fishing community targeting H. trunculus in the Bizerte lagoon. Further studies and more solid data on the reproductive cycle of the species are required before definitive management measures for this locally important artisanal fishery can be proposed. © Inter-Research 2010.

Vasconcelos P.,Instituto Nacional Of Recursos Biologicos Inrb | Moura P.,Instituto Nacional Of Recursos Biologicos Inrb | Barroso C.M.,University of Aveiro | Gaspar M.B.,Instituto Nacional Of Recursos Biologicos Inrb
Hydrobiologia | Year: 2011

The present study aimed at analysing the monthly variation in penis length (PL) during the reproductive cycle of the purple dye murex (Bolinus brandaris). Two hypotheses were tested: PL variation reflects male maturation and reproductive activity; PL variation bias the calculation of imposex indices based on penis measurement (RPLI and RPSI). Sampling was performed during 1 year in a population from Ria Formosa lagoon (Algarve coast, southern Portugal) with high incidence of imposex. Penis-bearing individuals were measured for shell length (SL) and PL, and two bio-physiological indices were calculated for both sexes, the general condition index (K) and the gonadosomatic index (GSI). PL presented monthly variation in both sexes, but while female PL showed small and random oscillation, male PL exhibited significant variation throughout the reproductive cycle (as evidenced by the similar and synchronous trends between male PL and GSI). These findings have implications both for reproduction studies and imposex monitoring: calculation of standardised PL (PL/SL) allows for gender identification without killing the organism and constitutes a useful penial index for assessing male maturation and reproductive activity; RPLI and RPSI should be applied cautiously in spatial and temporal comparisons of imposex severity in B. brandaris. © Springer Science+Business Media B.V. 2010.

Carvalho S.,Instituto Nacional Of Recursos Biologicos Inrb | Cunha M.R.,University of Aveiro | Pereira F.,Instituto Nacional Of Recursos Biologicos Inrb | Pousao-Ferreira P.,Instituto Nacional Of Recursos Biologicos Inrb | And 2 more authors.
Helgoland Marine Research | Year: 2012

The present study provides updated information on amphipod assemblages of the southern Portuguese coast, the most south-western part of continental Europe. The influence of depth and sediment type on the spatial distribution of shallow soft-bottom amphipods was tested by means of univariate and multivariate methods. Samples were collected down to 40 m depth within areas ranging from very fine sand to gravel. The ratio between density and diversity was found to increase with depth and from coarser to finer sediments. Both physical variables tested were found to play a major role in structuring amphipod assemblages. However, some dominance of depth was evident as samples were mainly separated according to this variable. Moreover, while only 15 taxa were common to all depth levels, 35 were collected from all sediment types. Both depth and sediment type may override the potential effects of geographical location, as samples from different areas along the southern Portuguese coast were biologically related. A peculiar habitat was sampled in this study: a maerl bed, which was confirmed to be a hotspot of density. Nevertheless, this habitat did not harbor a distinct amphipod assemblage but some taxa such as Caprella spp., Lembos websteri, lysianassids and Gammarella fucicola were preferentially collected there. The biogeographical analysis pointed out the occurrence of 8% of Mediterranean endemic species, confirming the influence of the Mediterranean Sea beyond the Strait of Gibraltar, and the Atlantic-Mediterranean feature of the amphipod fauna of this geographically relevant area. The present results support the need to interpret the spatial distribution patterns of marine species in relation to the combined effect of depth and sediment characteristics. © 2011 Springer-Verlag and AWI.

Santos M.N.,Instituto Nacional Of Recursos Biologicos Inrb | Leitao F.,Instituto Nacional Of Recursos Biologicos Inrb | Moura A.,Instituto Nacional Of Recursos Biologicos Inrb | Cerqueira M.,Instituto Nacional Of Recursos Biologicos Inrb | Monteiro C.C.,Instituto Nacional Of Recursos Biologicos Inrb
ICES Journal of Marine Science | Year: 2011

Although artificial reefs (ARs) have been deployed and studied worldwide, few studies have attempted to link the benthic community to fish populations. Three AR fish species (Diplodus bellottii, D. sargus, and D. vulgaris) were tested for the influence of the macrobenthic community at three similar ARs deployed in 1990, 1998, and 2002 off the Algarve (southern Portugal). Diplodus sargus density and biomass differed across ARs, and for D. bellottii and D. vulgaris, higher densities and biomass were observed between the oldest and the youngest ARs. The total available benthic biomass did not differ across habitat age, but the composition of macrofauna differed between older and the most recently deployed AR. The results underscore the importance of within-reef-age benthic composition variability as a determinant factor in structuring local fish populations. As the Algarve AR complex consists of reefs deployed at different times and having different benthic communities, management needs to focus more effort on conserving entire habitats rather than exclusively on maintaining the sustainability of fish resources. Hence, management plans for these areas need to be developed on a site-specific basis, according to the fish and macrobenthic community specificities. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.

Francisco M.L.,Instituto Nacional Of Recursos Biologicos Inrb | Gaspar M.B.,Instituto Nacional Of Recursos Biologicos Inrb
Marine Biology Research | Year: 2011

In the Ria Formosa lagoon (southern Portugal), the common cockle (Cerastoderma edule) has been commercially exploited using the harvesting knife (HK), an artisanal rudimentary tool used over the generations by local fishermen. More recently, the hand dredge (HD) has gained popularity among harvesters, because it is easier to operate and allows higher fishing yields per unit of effort (harvesting time). The damage caused by the gear on the shell and the way the gear is operated can affect post-discarding survival of undersized cockles, i.e. faster burrowing may determine higher chances of survival, thus reducing indirect mortality due to desiccation or predation. In this study, the burrowing response of cockles discarded after HD and HK harvesting were investigated in situ, during fishing surveys. After sorting a sample of undersized cockles (shell length <25 mm) was collected from the bycatch and placed into previously harvested areas which, according to fishermen, is common practice. No difference was found between the burrowing response of cockles after harvesting with HD and HK. Independently of the gear, 83% of the cockles burrowed within 15 min and only 10% of the individuals remained on the sediment surface 1 h after being discarded. The fast burrowing response indicates that neither harvesting method affects the physical condition of cockles. These results suggest that, contrary to what has been argued by local fishermen using HK, post-discarding survival is not directly linked with the different modus operandi of the gear. © 2011 Taylor & Francis.

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