Browsing by Author "Moreno, Ana"
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- Bycatch, discards and survival rates in the small‐scale cuttlefish trap fishery on sandy bottoms off the Algarve coast (southern Portugal)Publication . Vasconcelos, Paulo; Pereira, Fábio; Moreno, Ana; Gaspar, MiguelThis study reports a detailed description of the bycatch, discards and survival rates in the cuttlefish (Sepia officinalis) trap fishery off the Algarve coast (southern Portugal). A total of 86 fishing surveys involving 6,311 cuttlefish traps were performed between May and September from 2009 to 2014. Bycatch species were caught in 1,037 traps (bycatch catchability rate of 16.4%), comprising 1576 individuals with an overall weight of 268.3 kg. During the study period, bycatch CPUEs were 12.5 ind./50 traps and 2.1 kg/50 traps, with bycatch rates of 21.1% by number and 15.9% by weight. Thirty-four species (89.5% of bycatch taxa) were discarded at sea, corresponding to discard rates of 19.5% by number and 11.1% by weight. The short-snouted seahorse, Hippocampus hippocampus (L.), was the third most abundant bycatch species (11.6% No.; 0.4% kg) and the second most discarded (12.6% No.; 0.6% kg), being invariably discarded live and undamaged owing its conservation status. This markedly seasonal small-scale trap fishery constitutes a locally important socio-economic activity during spring and summer, characterised by low bycatch and discard rates, complemented by high survival rates of discards.
- Catches of Sepia officinalis in the small-scale cuttlefish trap fishery off the Algarve coast (southern Portugal)Publication . Pereira, Fábio; Vasconcelos, Paulo; Moreno, Ana; Gaspar, MiguelThe present study reports a detailed description of the catches of cuttlefish (Sepia officinalis) in the trap fishery performed seasonally off the Algarve coast (southern Portugal). A total of 86 fishing surveys were performed during the fishing season (May-September) from 2009 to 2014, on sandy bottoms at bathymetrics ranging from 8 to 10 m depth. During the whole study period, fishing operations involved 6311 cuttlefish traps with a gear catch rate of 37% (frequency of traps with cuttlefish) and a mean of 0.9 S. officinalis caught per trap. A total of 5883 S. officinalis (1424.0 kg) were caught, being only recorded 282 dead individuals (mortality rate of 4.6%). The mean fishing yield (standardised CPUE's in number and weight) was 46.6 individuals and 11.3 kg 50 traps(-1). Overall, males (n = 3188) outnumbered females (n = 2695), producing a significant male-biased (1 M: 0.85 F) sex ratio. On average, females were significantly larger and heavier (124.4 +/- 22.9 mm ML; 253.1 +/- 148.8 g TW) than males (121.9 +/- 24.0 mm ML; 230.7 +/- 143.1 g TW). Accordingly, the length-frequency distributions displayed significant gender differences, with 89.6% of females and 85.8% of males accomplishing the MCRS (100 mm ML). This markedly seasonal, highly sustainable and low impacting small-scale fishery constitutes a locally important socio-economic activity during spring and summer. Undamaged catches and highly fresh individuals further contribute to the considerable price reached by S. officinalis caught using this artisanal fishing gear.
- Designing a coastal monitoring marine biodiversity survey, using trammel nets and gillnets in PortugalPublication . Rufino, Marta M.; Maia, Catarina; Dinis, David; Farias, Inês; Moura, Teresa; Gomes, Pedro; Quaresma, Ivania; Martins, Rogélia; Figueiredo, Ivone; Serra-Pereira, Bárbara; Gaspar, Miguel; Moreno, AnaAlthough coastal areas are of great importance, they often lack long term monitoring surveys, which are essential for effective management, fisheries sustainability, and marine spatial planning. To address this, we conducted two experimental surveys aimed at assessing communities and their biodiversity, with the objective of designing a monitoring program for marine coastal biodiversity, based on gear type, depth, sampling arrangement, total net length, and panel position within the haul. Depth was found to be the most important factor shaping biodiversity, while gear type had the greatest impact on assessing species richness. Overall, both number of species and diversity increased with depth, though significant differences were only found between hauls deployed at 10 m and deeper (30-50 m). Trammel nets caught a larger number of species compared to gillnets, and there was evidence of an interaction between depth and gear, in terms of abundance and at the community level; samples taken deeper than 10 m showed more gear-related differences. We found that neither the panel position within the haul nor the number of nets had any impact on species diversity or abundance. Similarly, there was no evidence for an effect related to the arrangement of nets, as results were consistent whether using separated or continuous net panels. However, the number of nets used as a sampling unit significantly influenced the results, as the variation in species abundance and diversity with depth and gear type was similar, when 20 or 30 nets were used, but became more variable when only 10 nets were used, even with increased replication. We concluded that both trammel nets and gillnets should be included in a coastal biodiversity monitoring program, as each catches a different set of species, including both demersal and pelagic taxa. Further, we recommend using a minimum of 20 nets (ideally 30+) per station, with replication. The evaluated monitoring system has a minimal impact on the ecosystem, can be easily deployed using commercial vessels and effectively captures a large number of species, being thus, highly recommended to be used in coastal monitoring surveys.
- Evaluating model outputs using integrated global speleothem records of climate change since the last glacialPublication . Comas-Bru, Laia; Harrison, Sandy P.; Werner, Martin; Rehfeld, Kira; Scroxton, Nick; C. Veiga-Pires, C.; Ahmad, Syed Masood; Brahim, Yassine Ait; Mozhdehi, Sahar Amirnezhad; Arienzo, Monica; Atsawawaranunt, Kamolphat; Baker, Andy; Braun, Kerstin; Breitenbach, Sebastian; Burstyn, Yuval; Chawchai, Sakonvan; Columbu, Andrea; Deininger, Michael; Demeny, Attila; Dixon, Bronwyn; Hatvani, István Gábor; Hu, Jun; Kaushal, Nikita; Kern, Zoltan; Labuhn, Inga; Lachniet, Matthew S.; Lechleitner, Franziska A.; Lorrey, Andrew; Markowska, Monika; Nehme, Carole; Novello, Valdir F.; Oster, Jessica; Perez-Mejias, Carlos; Pickering, Robyn; Sekhon, Natasha; Wang, Xianfeng; Warken, Sophie; Atkinson, Tim; Ayalon, Avner; Baldini, James; Bar-Matthews, Miryam; Bernal, Juan Pablo; Boch, Ronny; Borsato, Andrea; Boyd, Meighan; Brierley, Chris; Cai, Yanjun; Carolin, Stacy; Cheng, Hai; Constantin, Silviu; Couchoud, Isabelle; Cruz, Francisco; Denniston, Rhawn; Dragusin, Virgil; Duan, Wuhui; Ersek, Vasile; Finne, Martin; Fleitmann, Dominik; Fohlmeister, Jens; Frappier, Amy; Genty, Dominique; Holzkamper, Steffen; Hopley, Philip; Johnston, Vanessa; Kathayat, Gayatri; Keenan-Jones, Duncan; Koltai, Gabriella; Li, Ting-Yong; Lone, Mahjoor Ahmad; Luetscher, Marc; Mattey, Dave; Moreno, Ana; Moseley, Gina; Psomiadis, David; Ruan, Jiaoyang; Scholz, Denis; Sha, Lijuan; Smith, Andrew Christopher; Strikis, Nicolas; Treble, Pauline; Unal-Imer, Ezgi; Vaks, Anton; Vansteenberge, Stef; Voarintsoa, Ny Riavo G.; Wong, Corinne; Wortham, Barbara; Wurtzel, Jennifer; Zhang, HaiweiAlthough quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data-model comparisons. Here, we illustrate this using 456 globally distributed speleothem delta O-18 records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data-model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on delta O-18 values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices.