Browsing by Author "Henriques, Miguel"
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- Assessment of catches, landings and fishing effort as useful tools for MPA managementPublication . Batista, Marisa I.; Costa, Bárbara Horta e; Gonçalves, Leonel; Henriques, Miguel; Erzini, Karim; Caselle, Jennifer E.; Gonçalves, Emanuel João; Cabral, HenriqueMarine protected areas (MPAs) have been widely recognized as a tool to achieve both fisheries management and conservation goals. Simultaneously achieving these multiple goals is difficult due to conflicts between conservation (often long-term) and economic (often short-term) objectives. MPA implementation often includes additional control measures on fisheries (e.g. vessel size restrictions, gear exclusion, catch controls) that in the short-term may have impacts on local fishers’ communities. Thus, monitoring fisheries catches before, during and after MPA implementation is essential to document changes in fisheries activities and to evaluate the impact of MPAs in fishers’ communities. Remarkably, in contrast with standard fisheries-independent biological surveys, these data are rarely measured at appropriate spatial scales following MPA implementation. Here, the effects of MPA implementation on local fisheries are assessed in a temperate MPA (Arrábida Marine Park, Portugal), using fisheries monitoring methods combining spatial distribution of fishing effort, on-board observations and official landings statistics at scales appropriate to the Marine Park. Fisheries spatial distribution, fishing effort, on-board data collection and official landings registered for the same vessels over time were analysed between 2004 and 2010. The applicability and reliability of using landings statistics alone was tested (i.e. when no sampling data are available) and we conclude that landings data alone only allow the identification of general patterns. The combination of landings information (which is known to be unreliable in many coastal communities) with other methods, provides an effective tool to evaluate fisheries dynamics in response to MPA implementation. As resources for monitoring socio-ecological responses to MPAs are frequently scarce, the use of landings data calibrated with fisheries information (from vessels, gear distribution and on-board data) is a valuable tool applicable to many worldwide coastal small-scale fisheries.
- Biomares, a LIFE project to restore and manage the biodiversity of Prof. Luiz Saldanha Marine ParkPublication . Cunha, Alexandra H.; Erzini, Karim; Serrão, Ester A.; Gonçalves, Emanuel João; Borges, Rita Alexandra; Henriques, Miguel; Henriques, Victor; Guerra, Miriam; Duarte, Carlos M.; Marbá, Núria; Fonseca, MarkThe Marine Park Prof. Luiz Saldanha, in the coast of Arrábida, is the first marine park in continental Portugal. This area is a Nature 2000 site and is considered to be a hotspot for European marine biodiversity. In 2005, the management plan of the park was implemented, ending several habitat menaces, thereby allowing an application to the LIFE—NATURE Programme. The LIFE-BIOMARES project aimed at the restoration and management of the biodiversity of the marine park through several actions. The restoration of the seagrass prairies that were completely destroyed by fishing activities and recreational boating, was one of the most challenging. It included the transplanting of seagrasses from donor populations and the germination of seagrass seeds for posterior plantation to maintain genetic diversity in the transplanted area. One of the most popular actions was the implementation of environmental friendly moorings to integrate recreational use of the area with environmental protection. Several dissemination and environmental education actions concerning the marine park and the project took place and contributed to the public increase of the park acceptance. The seabed habitats were mapped along the park and a surrounding area to 100 m depth in order to create a habitat cartography of the park and to help locate alternative fishing zones. Biodiversity assessments for macrofauna revealed seasonal variations and an effect of the protection status. Preliminary results are presented and show that the marine park regulations are having a positive effect on biodiversity conservation and sustainable fisheries, thereby showing that these kind of conservation projects are important to disseminate coastal conservation best practices. The Biomares project is a model project that can be followed in the implementation of marine reserves and the establishment of the Natura 2000 marine network.
- Estimating the size of "Uca tanger" (Crustacea: Ocypodidae) without massive crab capturePublication . Lourenço, Rita; Paula, José R.; Henriques, MiguelUca tangeri (Eydoux, 1835) is the only species of fiddler crab that occurs in Portugal, where it mainly inhab-its salt marshes in the south and southwest coasts. Individuals spend most of their time on and around their galleries, bur-rowing structures which they typically create and maintain in muddy substrate. Capturing fiddler crabs in nature is extreme-ly difficult and can be destructive for their habitat. Once disturbed, U. tangeri tend to hide in their burrow, and their capture usually involves the destruction of the upper part of the burrow. In the present study, a method for estimating the carapace length of the fiddler indirectly, using the diameter of the burrow opening, is proposed. Significant sex-specific relationships between the diameter of the burrow opening and the occupant’s length were found. Although the mean length of the cara-pace was not significantly different between sexes,
- Juveniles of non-resident fish found in sheltered rocky subtidal areasPublication . Henriques, Miguel; Almada, Vítor CarvalhoJuvenile fishes of 22 species collected on a rocky shore area at Arrábida (Portugal) fell into three groups: (i) incidentals (four species); (ii) those in transit to a nearby estuary (three species); and (iii) nursery residents (15 species). For groups ii and iii this habitat seems to play an important role in their early life stages.
- On the phylogenetic affinities of Centrolabrus trutta and Centrolabrus caeruleus (Perciformes: Labridae) to the genus Symphodus: Molecular, meristic and behavioural evidencesPublication . Almada, Vitor; Almada, Frederico José Oliveira de; Henriques, Miguel; Santos, Ricardo Serrão; Brito, AlbertoPhylogenetic analysis of partial 12S and 16S mitochondrial rDNA regions, together with meristic and ethological data, has revealed that Centrolabrus trutta (Lowe, 1833), a species occurring in the Canaries and Madeira, and its close relative Centrolabrus caeruleus (Azevedo, 1999) from the Azores, are more closely related to most species of the genus Symphodus than to Centrolabrus exoletus (Linnaeus, 1758). Underwater behavioural observations showed that C. trutta, like C. caeruleus, shares with most Symphodus species sexual dichromatism, male nest building and male parental care of the eggs, traits that are absent in C. exoletus. The low number of base substitutions found between C. trutta and C. caeruleus indicates that these species are very closely related. The 16S rDNA data suggest that C. trutta, C. caeruleus and S. roissali form a monophyletic group. The analysis of the 16S rDNA data also showed that S. melanocercus is the sister species of C. exoletus and it is not closely related to the species of Symphodus included in this study. Lack of nest building and parental behaviour in S. melanocercus, and its marked divergence to other members of the genus Symphodus in meristic characters, also stress its affinity with C. exoletus and its separation from the remaining species of Symphodus. Our data and the evidence available in the literature led us to propose the inclusion of C. trutta and C. caeruleus in the genus Symphodus, while S. melanocercus must be transferred to the genus Centrolabrus.
- Ontogenetic shifts in patterns of microhabitat utilization in the small-headed clingfish, Apletodon dentatus (Gobiesocidae)Publication . Gonçalves, Emanuel João; Barbosa, Miguel; Cabral, Henrique; Henriques, MiguelThe patterns of microhabitat utilization by the clingfish Apletodon dentatus were investigated, based on SCUBA diving surveys at the Arr´abida Marine Park (Portugal). In all inspected microhabitats, this species was only found in algal turfs, sea urchins and boulders. The association of A. dentatus with sea urchins is here analysed for the first time. There was a differential utilization of the microhabitats, with small juveniles recruiting to algal turfs, intermediate individuals found in association with the sea urchins Paracentrotus lividus and Sphaerechinus granularis and larger fish occurring mainly in boulders. The depth distribution patterns are also analysed.
- Opeatogenys gracilis (Pisces: Gobiesocidae): An overlooked species or another ‘Mediterranean endemism’ found in Atlantic waters?Publication . Gonçalves, Emanuel João; Beldade, Ricardo; Henriques, MiguelThe occurrence of Opeatogenys gracilis outside the Mediterranean Sea is confirmed for the first time. This is probably a more common species than previously thought, but its apparent complete dependence on seagrass beds suggests the possibility of including it in the IUCN threatened species list. Some sex differences are described and a complete meristic and morphometric description of the species is presented. The occurrence of the species in the north-east Atlantic indicates that it might be a recent dispersal from the Mediterranean Sea, or an overlooked part of the autochthonous fauna.
- A rapid and inexpensive molecular technique to discriminate the north-eastern Atlantic and Mediterranean Atherina species and its potential applications in ecology and larval identificationPublication . Almada, Vítor Carvalho; Francisco, Sara Martins; Rosa, Inês; Domingues, Vera dos Santos; Cabral, Henrique; Almada, Frederico José Oliveira de; Henriques, Miguel; Robalo, Joana IsabelThis note describes a rapid and inexpensive Restriction Fragment Length Polymorphism technique to discriminate all species of Atherina (Pisces: Atherinidae) of the north-eastern Atlantic and the Mediterranean. This technique is based on digestion of a fragment of the 12S ribosomal RNA (12SrRNA) gene region of mitochondrial DNA with restriction enzymes that recognize species-specific nucleotide sites. The three currently recognized species in the area, as well as two additional forms awaiting formal description, can be discriminated using a set of four endonucleases. We argue that this simple and fast technique may be of great help in the identification of young stages and in ecological surveys.
- Rapid shifts in a marine fish assemblage follow fluctuations in winter sea conditionsPublication . Henriques, Miguel; Gonçalves, Emanuel João; Almada, Vítor CarvalhoPatterns of interannual variation are described for an inshore fish assemblage off the Arrábida rocky coast (Portugal). During an 11 yr period, the fish assemblage showed pronounced changes especially within its tropical, warm-temperate and cold-temperate elements. These changes followed a fluctuating pattern connected with the North Atlantic Oscillation (NAO) with a series of years where the modifications were slight, interspersed with years where faunal changes were very rapid, affecting up to 35% of the total number of species recorded in those years. After a transition year from a cold to a warm period or vice versa, the majority of the newcomers from the preceding phase were eliminated. Winter conditions, but not summer conditions, were good predictors of the observed patterns. Increases in sea surface temperature (SST) were associated with increases in the proportions of tropical and warm-temperate fish and with decreases in the proportion of cold-temperate elements, the reverse being true for decreases in SST. Interannual variation in faunal composition was not simply a consequence of changes in SST. Changes in other factors such as current flow direction and transport mechanisms, capable of bringing fishes from different biogeographical sources, may also play a role in the observed patterns. The influence of the NAO is therefore not only mediated by its effects on SST but also by the changes it induces in wind and current patterns along the Portuguese shore. Long-term trends caused by persistent changes, like those involving global warming, may be masked by the fact that at an intermediate time scale, faunal changes are characterised by a succession of oscillations rather than by a steady modification in a single direction. This outlines the importance of long-term monitoring data, since short-term studies may only capture single phases of a complex oscillation, giving a false picture of the overall pattern of change.
- Reclassification of Lepadogaster candollei based on molecular and meristic evidence with a redefinition of the genus LepadogasterPublication . Almada, Frederico José Oliveira de; Henriques, Miguel; Levy, André; Pereira, Ana Martins; Robalo, Joana Isabel; Almada, Vítor CarvalhoInexistente