Otoliths and scales were used to determine age and growth of: Boops boops (Linnaeus, 1758), Diplo... more Otoliths and scales were used to determine age and growth of: Boops boops (Linnaeus, 1758), Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), Diplodus sargus (Linnaeus, 1758), Lithognathus mormyrus (Linnaeus, 1758), Pagellus acarne (Risso, 1827), Pagellus erythrinus (Linnaeus, 1758) and Spondyliosoma cantharus (Linnaeus, 1758). These structures came from previous studies conducted in southern Portugal, and complemented by market sampling and beach seining. Von Bertalanffy growth functions were estimated with otolith and scale readings. Results indicate that otoliths are better structures for ageing these species but scales can also be used as a non-destructive technique and with satisfactory results. The exceptions were P. erythrinus and S. cantharus for which scales provided better results.
The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Mad... more The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Madeira Island. As a result of their small size, remote location and harsh sea conditions only a few studies have been conducted to describe their marine species diversity. We were able to identify 29 new coastal fish species, an increase of 33% in the ichthyofauna described for these islands (n = 88). There is a prevalence of species with tropical affinities and only 2.3% (n = 2) are endemic to Macaronesia. Considered a stepping-stone colonization vector from the nearest continental shore, as proposed by other authors for this region, the Selvagens Islands host 34.1% of the ichthyofauna described for the much larger Canary Islands (n species = 258, submerged area n SelvagensIs. = 2.3%) and 47.3% of the ichthyofauna described for the more distantly located Madeira Island (n species = 186, submerged area n SelvagensIs. = 17.9%). Interestingly, 6.8% (n = 6) of the species failed to bridge the gap between the Selvagens Islands and Madeira Island. Data collected so far showed no trend toward an increasing number of species with high dispersal capability. The Selvagens Islands are an example of a high coastal species diversity occurring even in very small areas of the northeastern Atlantic Ocean.
The macrofauna assemblages of a XVII th century shipwreck off southern Portugal were studied and ... more The macrofauna assemblages of a XVII th century shipwreck off southern Portugal were studied and compared with those of nearby natural reefs and sandy bottoms, by underwater visual census. A total of 11 173 specimens of 224 different fauna taxa and 12 phyla were recorded. Natural reefs had the highest density of specimens (35 122 / 1000 m 2 ) followed by the shipwreck (21 392 / 1000 m 2 ) and the sandy bottoms (3771 / 1000 m 2 ). Three biodiversity indices were estimated (Margalef, Shannon-Wiener and Pielou), with the natural reefs showing the highest values. However, the shipwreck presented values relatively similar to those of the natural reefs for the Shannon-Wiener and Pielou indices. The three habitats were clearly distinguishable by multivariate statistical analysis, with the average dissimilarity between sand and shipwreck, and between sand and natural reefs being much higher than that between the shipwreck and the natural reefs. The shipwreck had higher abundances of some commercially important species, such as the pouting Trisopterus luscus, European conger Conger conger, and common spider crab Maja squinado, as well as some vulnerable and threatened species such as the pink seafan Eunicella verrucosa. The results presented emphasize the importance of this habitat on the southern Portuguese coast.
The age and growth of the Helicolenus dactylopterus (Delaroche, 1809) in the Azorean waters were ... more The age and growth of the Helicolenus dactylopterus (Delaroche, 1809) in the Azorean waters were studied using whole and sliced otolith readings. Individuals were collected during demersal surveys carried out around the Azores islands and its most important fishing banks and also from commercial landings. A total of 1024 individuals were measured, weighed and their sex was determined. Individuals ranged from 3 to 49 cm total length (TL) and their estimated ages between 0 and 32 years old. The otoliths showed the typical teleost fish pattern with alternated opaque and hyaline rings. Significant differences between sliced and whole otolith readings were found, especially after 7 years old (>25 cm TL). Sliced otoliths were found easier to read, regardless of TL or age. Comparisons with other studies for the Azores region and other areas are discussed.
... Short communication. Site fidelity and movements of gilthead sea bream (Sparus aurata) in a c... more ... Short communication. Site fidelity and movements of gilthead sea bream (Sparus aurata) in a coastal lagoon (Ria Formosa, Portugal). ... Keywords: Sparus aurata; acoustic telemetry; site fidelity; fish movement; Ria Formosa. Article Outline. ...
Pesca y Acuicultura. Serie Recursos Pesqueros-Junta de Andalucía, 2007
-[Fishing for bivalves in the ocean coastline of the Southwest coast of the Iberian Peninsula: fi... more -[Fishing for bivalves in the ocean coastline of the Southwest coast of the Iberian Peninsula: fishing grounds and equipment description, management measures, biology of the commercial species and bivalve species catalogue] by Gaspar, MB; Moreno, O.; Díaz, A.; Manzano, C.(eds.); Pereira, A.; Palanco, I.; Rufino, M.(2007) in Spanish
The Mediterranean parrotfish Sparisoma cretense is one of the few temperate species of the Scarid... more The Mediterranean parrotfish Sparisoma cretense is one of the few temperate species of the Scaridae family and the only one to be found in Mediterranean waters (Bernardi et al., 2000). It is a common species in the Macaronesian archipelagos (Azores, Madeira, Canaries and Cape Verde islands), north-west coast of Africa and in the southern and eastern coasts of the Mediterranean (Gonzalez, 1993; Bernardi et al., 2000). Although the Mediterranean parrotfish is common in the eastern and southern coasts of the ...
Three hatchery produced and reared (HPR) and five wild white sea bream (Diplodus sargus) were dou... more Three hatchery produced and reared (HPR) and five wild white sea bream (Diplodus sargus) were double tagged with Vemco V8SC-2L acoustic transmitters and Floy Tag T-bar anchor tags, and released on artificial reefs located near a natural reef off the southern coast of Portugal. Passive telemetry was used to monitor movements of the white sea bream over a nine week
Acoustic telemetry and standard tag-recapture were used to determine the home range and residency... more Acoustic telemetry and standard tag-recapture were used to determine the home range and residency of juveniles and sub-adults of Diplodus sargus and Diplodus vulgaris in the Ria Formosa (Portugal) coastal lagoon. Maximum time between recaptures for the standard tag-recapture method was 128 days for D. sargus and 30 days for D. vulgaris. The majority of the fish were recaptured in the vicinity of the tagging location. Fish tagged with acoustic transmitters had a maximum period of time between first and last detections of 62 days for D. sargus and 260 days for D. vulgaris. Minimum convex polygons areas ranged between 148 024m2 and 525 930m2 for D. sargus and between 23 786m2 and 42 134m2 for D. vulgaris. Both species presented a high residency index between first and last detections. Two D. sargus tagged with acoustic tags were recaptured by fishermen outside the coastal lagoon at distances of 12km and 90km from the tagging position, providing evidence that this species leaves the Ria...
Acoustic telemetry and standard tag-recapture were used to determine the home range and residency... more Acoustic telemetry and standard tag-recapture were used to determine the home range and residency of juveniles and sub-adults of Diplodus sargus and Diplodus vulgaris in the Ria Formosa (Portugal) coastal lagoon. Maximum time between recaptures for the standard tag-recapture method was 128 days for D. sargus and 30 days for D. vulgaris. The majority of the fish were recaptured in the
Studies that combine both the ecological responses of marine species and protection measures with... more Studies that combine both the ecological responses of marine species and protection measures with movement patterns and habitat use are of major importance in order to better understand the performance of marine protected areas (MPA) and how species respond to their implementation. However, few studies have assessed MPA performance by relating local individual movement patterns and the observed reserve effects. In this study, we combined acoustic telemetry with abundance estimates to study the early effects of a recently established small coastal MPA on the local populations of white seabream. The results show that even small, recently established coastal MPAs can increase the abundance and biomass of commercial fish species, provided that target species have small home ranges and exhibit high site fidelity.
Several studies have reported the existence of ectoparasites in the stomach contents of Diplodus ... more Several studies have reported the existence of ectoparasites in the stomach contents of Diplodus sargus. The cleaning behaviour has, however, never been previously observed for this species. In this short study, we report the first observations of the cleaning behaviour of D. sargus. These observations were in two yachting marinas, located in the Portuguese western coast between the months of April and August. The cleaning behaviour was only observed towards two Mugilidae species, Chelon labrosus and Mugil cephalus.
Marine protected areas (MPAs) are today’s most important tools for the spatial management and con... more Marine protected areas (MPAs) are today’s most important tools for the spatial management and conservation of marine species. Yet, the true protection that they provide to individual fish is unknown, leading to uncertainty associated with MPA effectiveness. In this study, conducted in a recently established coastal MPA in Portugal, we combined the results of individual home range estimation and population distribution models for 3 species of commercial importance and contrasting life histories to infer (1) the size of suitable areas where they would be fully protected and (2) the vulnerability to fishing mortality of each species. Results show that the relationship between MPA size and effective protection is strongly modulated by both the species’ home range and the distribution of suitable habitat inside and outside the MPA. This approach provides a better insight into the true potential of MPAs in effectively protecting marine species, since it can reveal the size and location of the areas where protection is most effective and a clear, quantitative estimation of the vulnerability to fishing throughout an entire MPA.
Otoliths and scales were used to determine age and growth of: Boops boops (Linnaeus, 1758), Diplo... more Otoliths and scales were used to determine age and growth of: Boops boops (Linnaeus, 1758), Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), Diplodus sargus (Linnaeus, 1758), Lithognathus mormyrus (Linnaeus, 1758), Pagellus acarne (Risso, 1827), Pagellus erythrinus (Linnaeus, 1758) and Spondyliosoma cantharus (Linnaeus, 1758). These structures came from previous studies conducted in southern Portugal, and complemented by market sampling and beach seining. Von Bertalanffy growth functions were estimated with otolith and scale readings. Results indicate that otoliths are better structures for ageing these species but scales can also be used as a non-destructive technique and with satisfactory results. The exceptions were P. erythrinus and S. cantharus for which scales provided better results.
The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Mad... more The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Madeira Island. As a result of their small size, remote location and harsh sea conditions only a few studies have been conducted to describe their marine species diversity. We were able to identify 29 new coastal fish species, an increase of 33% in the ichthyofauna described for these islands (n = 88). There is a prevalence of species with tropical affinities and only 2.3% (n = 2) are endemic to Macaronesia. Considered a stepping-stone colonization vector from the nearest continental shore, as proposed by other authors for this region, the Selvagens Islands host 34.1% of the ichthyofauna described for the much larger Canary Islands (n species = 258, submerged area n SelvagensIs. = 2.3%) and 47.3% of the ichthyofauna described for the more distantly located Madeira Island (n species = 186, submerged area n SelvagensIs. = 17.9%). Interestingly, 6.8% (n = 6) of the species failed to bridge the gap between the Selvagens Islands and Madeira Island. Data collected so far showed no trend toward an increasing number of species with high dispersal capability. The Selvagens Islands are an example of a high coastal species diversity occurring even in very small areas of the northeastern Atlantic Ocean.
The macrofauna assemblages of a XVII th century shipwreck off southern Portugal were studied and ... more The macrofauna assemblages of a XVII th century shipwreck off southern Portugal were studied and compared with those of nearby natural reefs and sandy bottoms, by underwater visual census. A total of 11 173 specimens of 224 different fauna taxa and 12 phyla were recorded. Natural reefs had the highest density of specimens (35 122 / 1000 m 2 ) followed by the shipwreck (21 392 / 1000 m 2 ) and the sandy bottoms (3771 / 1000 m 2 ). Three biodiversity indices were estimated (Margalef, Shannon-Wiener and Pielou), with the natural reefs showing the highest values. However, the shipwreck presented values relatively similar to those of the natural reefs for the Shannon-Wiener and Pielou indices. The three habitats were clearly distinguishable by multivariate statistical analysis, with the average dissimilarity between sand and shipwreck, and between sand and natural reefs being much higher than that between the shipwreck and the natural reefs. The shipwreck had higher abundances of some commercially important species, such as the pouting Trisopterus luscus, European conger Conger conger, and common spider crab Maja squinado, as well as some vulnerable and threatened species such as the pink seafan Eunicella verrucosa. The results presented emphasize the importance of this habitat on the southern Portuguese coast.
The age and growth of the Helicolenus dactylopterus (Delaroche, 1809) in the Azorean waters were ... more The age and growth of the Helicolenus dactylopterus (Delaroche, 1809) in the Azorean waters were studied using whole and sliced otolith readings. Individuals were collected during demersal surveys carried out around the Azores islands and its most important fishing banks and also from commercial landings. A total of 1024 individuals were measured, weighed and their sex was determined. Individuals ranged from 3 to 49 cm total length (TL) and their estimated ages between 0 and 32 years old. The otoliths showed the typical teleost fish pattern with alternated opaque and hyaline rings. Significant differences between sliced and whole otolith readings were found, especially after 7 years old (>25 cm TL). Sliced otoliths were found easier to read, regardless of TL or age. Comparisons with other studies for the Azores region and other areas are discussed.
... Short communication. Site fidelity and movements of gilthead sea bream (Sparus aurata) in a c... more ... Short communication. Site fidelity and movements of gilthead sea bream (Sparus aurata) in a coastal lagoon (Ria Formosa, Portugal). ... Keywords: Sparus aurata; acoustic telemetry; site fidelity; fish movement; Ria Formosa. Article Outline. ...
Pesca y Acuicultura. Serie Recursos Pesqueros-Junta de Andalucía, 2007
-[Fishing for bivalves in the ocean coastline of the Southwest coast of the Iberian Peninsula: fi... more -[Fishing for bivalves in the ocean coastline of the Southwest coast of the Iberian Peninsula: fishing grounds and equipment description, management measures, biology of the commercial species and bivalve species catalogue] by Gaspar, MB; Moreno, O.; Díaz, A.; Manzano, C.(eds.); Pereira, A.; Palanco, I.; Rufino, M.(2007) in Spanish
The Mediterranean parrotfish Sparisoma cretense is one of the few temperate species of the Scarid... more The Mediterranean parrotfish Sparisoma cretense is one of the few temperate species of the Scaridae family and the only one to be found in Mediterranean waters (Bernardi et al., 2000). It is a common species in the Macaronesian archipelagos (Azores, Madeira, Canaries and Cape Verde islands), north-west coast of Africa and in the southern and eastern coasts of the Mediterranean (Gonzalez, 1993; Bernardi et al., 2000). Although the Mediterranean parrotfish is common in the eastern and southern coasts of the ...
Three hatchery produced and reared (HPR) and five wild white sea bream (Diplodus sargus) were dou... more Three hatchery produced and reared (HPR) and five wild white sea bream (Diplodus sargus) were double tagged with Vemco V8SC-2L acoustic transmitters and Floy Tag T-bar anchor tags, and released on artificial reefs located near a natural reef off the southern coast of Portugal. Passive telemetry was used to monitor movements of the white sea bream over a nine week
Acoustic telemetry and standard tag-recapture were used to determine the home range and residency... more Acoustic telemetry and standard tag-recapture were used to determine the home range and residency of juveniles and sub-adults of Diplodus sargus and Diplodus vulgaris in the Ria Formosa (Portugal) coastal lagoon. Maximum time between recaptures for the standard tag-recapture method was 128 days for D. sargus and 30 days for D. vulgaris. The majority of the fish were recaptured in the vicinity of the tagging location. Fish tagged with acoustic transmitters had a maximum period of time between first and last detections of 62 days for D. sargus and 260 days for D. vulgaris. Minimum convex polygons areas ranged between 148 024m2 and 525 930m2 for D. sargus and between 23 786m2 and 42 134m2 for D. vulgaris. Both species presented a high residency index between first and last detections. Two D. sargus tagged with acoustic tags were recaptured by fishermen outside the coastal lagoon at distances of 12km and 90km from the tagging position, providing evidence that this species leaves the Ria...
Acoustic telemetry and standard tag-recapture were used to determine the home range and residency... more Acoustic telemetry and standard tag-recapture were used to determine the home range and residency of juveniles and sub-adults of Diplodus sargus and Diplodus vulgaris in the Ria Formosa (Portugal) coastal lagoon. Maximum time between recaptures for the standard tag-recapture method was 128 days for D. sargus and 30 days for D. vulgaris. The majority of the fish were recaptured in the
Studies that combine both the ecological responses of marine species and protection measures with... more Studies that combine both the ecological responses of marine species and protection measures with movement patterns and habitat use are of major importance in order to better understand the performance of marine protected areas (MPA) and how species respond to their implementation. However, few studies have assessed MPA performance by relating local individual movement patterns and the observed reserve effects. In this study, we combined acoustic telemetry with abundance estimates to study the early effects of a recently established small coastal MPA on the local populations of white seabream. The results show that even small, recently established coastal MPAs can increase the abundance and biomass of commercial fish species, provided that target species have small home ranges and exhibit high site fidelity.
Several studies have reported the existence of ectoparasites in the stomach contents of Diplodus ... more Several studies have reported the existence of ectoparasites in the stomach contents of Diplodus sargus. The cleaning behaviour has, however, never been previously observed for this species. In this short study, we report the first observations of the cleaning behaviour of D. sargus. These observations were in two yachting marinas, located in the Portuguese western coast between the months of April and August. The cleaning behaviour was only observed towards two Mugilidae species, Chelon labrosus and Mugil cephalus.
Marine protected areas (MPAs) are today’s most important tools for the spatial management and con... more Marine protected areas (MPAs) are today’s most important tools for the spatial management and conservation of marine species. Yet, the true protection that they provide to individual fish is unknown, leading to uncertainty associated with MPA effectiveness. In this study, conducted in a recently established coastal MPA in Portugal, we combined the results of individual home range estimation and population distribution models for 3 species of commercial importance and contrasting life histories to infer (1) the size of suitable areas where they would be fully protected and (2) the vulnerability to fishing mortality of each species. Results show that the relationship between MPA size and effective protection is strongly modulated by both the species’ home range and the distribution of suitable habitat inside and outside the MPA. This approach provides a better insight into the true potential of MPAs in effectively protecting marine species, since it can reveal the size and location of the areas where protection is most effective and a clear, quantitative estimation of the vulnerability to fishing throughout an entire MPA.
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