Browsing by Author "Chainho, Paula"
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- Comparison of the efficiency of different eradication treatments to minimize the impacts caused by the invasive tunicate Styela plicata in mussel aquaculturePublication . Santos, Pedro M.; Venâncio, Eliana; Dionísio, Maria Ana; Heumüller, Joshua; Chainho, Paula; Pombo, AnaIn 2017, aquaculture producers of the Albufeira lagoon, Portugal, reported an invasion of tunicates that was disrupting mussel production, particularly the tunicate Styela plicata (Lesueur, 1823). A totally effective eradication method still does not exist, particularly for S. plicata, and the effects of the eradication treatments on bivalves’ performance are also poorly understood. Our study examined the effectiveness of eradication treatments using three laboratory trials and five treatments (air exposure, freshwater immersion, sodium hypochlorite, hypersaline solution and acetic acid) for S. plicata, as well as their effects on survival and growth of blue mussel Mytilus edulis Linnaeus, 1758. While air exposure and freshwater immersion caused a 27% mortality rate in S. plicata, the acetic acid treatment was the most effective in eliminating this species (>90% mortality). However, a 33–40% mortality rate was registered in mussels. Both species were not affected by the hypersaline treatment in the last trial, but the sodium hypochlorite treatment led to a 57% mortality rate in mussels. Differences in mussels’ growth rates were not detected. These trials represent a step forward in responding to the needs of aquaculture producers. However, further studies are needed to investigate the susceptibility of tunicates to treatments according to sexual maturation, as well as to ensure minimum mussel mortality in the most effective treatments, and to better understand the effects on mussel physiological performance in the long-term.
- How nematode morphometric attributes integrate with taxonomy-based measures along an estuarine gradientPublication . Sroczynska, Kasia; Conde, Anxo; Chainho, Paula; Adão, HelenaNematodes are highly susceptible to environmental change and possess a wide array of morphological and functional characteristics for the assessment of the “Good Environmental Status”, within Marine Strategy Framework Directive. However, while the taxonomic sufficiency of nematodes in detecting spatial gradients and related ecological niche conditions is well recognized, very little is known about nematodes functional morphometric attributes in response to environmental drivers. To explore this knowledge gap, we aimed to assess the efficacy and efficiency of nematode morphometric attributes (length, width, length/width ratio, biomass) in detecting spatial patterns along a Portuguese estuarine gradient, and compare it with the taxonomic approach. We hypothesized that abundance data weighted by the morphometric attributes will have a higher explanatory power in detecting spatial patterns than using abundance of morphometric data alone. Based on the recent recommendations regarding the time and cost related efficacy of methods in biomonitoring and ecological assessments we also hypothesized that a reduced dataset based on the most common genera will suffice to capture the same distributional patterns displayed by the whole assemblage. Our results demonstrated that dataset solely based on genera abundances had consistently better explanatory power than combined datasets or morphometric datasets alone, however, combined dataset provided different spatial patterns and performed better at discriminating estuary areas. The main gradients described by the taxonomy-based dataset were related to the sediment particle size and water depth. Considering combined datasets, spatial discrimination was mainly driven by the variation in dissolved oxygen % saturation, pointing out to the importance of this variable in determining estuarine conditions substantial for nematodes morphometric distributional patterns. The same analysis repeated for the most frequent genera resulted in similar distributional patterns as for the whole assemblage dataset, clearly demonstrating that spatial estuarine gradients can be sufficiently described by using only the most frequent genera. Such information may substantially increase the efficiency of bioassessment surveys by reducing the cost and work associated with identification and measurements of all of the individual nematode genera.
- Insight into aquaculture's potential of marine annelid worms and ecological concerns: a reviewPublication . Pombo, Ana; Baptista, Teresa; Granada, Luana; Ferreira, Susana M. F.; Gonçalves, Sílvia C.; Anjos, Catarina; Sá, Erica; Chainho, Paula; Fonseca, Luís Cancela da; Fidalgo e Costa, Pedro; Costa, José L.Polychaetes are marine annelid worms that can contribute to aquaculture diversification. Its culture has been viable, and commercially attempted, but intensive production has progressed only in few countries around the world. In the countries with no production, marine polychaetes are imported or harvested. A strong and sustained research investment provided to a better understanding of the nutritional requirements and reproduction of some species. Recent studies showed new technical improvements, which can lead to an important progress in productivity and give a new impetus to the polychaete production. Some marine worm species were identified as good candidates for integrated multitrophic aquaculture. The development of cost-effective aquaculture techniques for marine annelid worms is essential to ensure a balance between commercial interests and the preservation of ecosystems. The influence of polychaete aquaculture on the environment and vice versa raise important concerns related to ecological security and sustainability of this activity. This review focus on the main technical improvements and advances that have been made in areas as diverse as: aquaculture potential of polychaetes, reared species, main species used worldwide, and highlights biological and ecological concerns, important challenges and recommendations.
- Insight into aquaculture’s potential of marine annelid worms and ecological concerns: a reviewPublication . Pombo, Ana; Baptista, Teresa; Granada, Luana; Ferreira, Susana M. F.; Gonçalves, Sílvia C.; Anjos, Catarina; Sá, Erica; Chainho, Paula; Fonseca, Luís Cancela da; Costa, Pedro Fidalgo e; Costa, José L.Polychaetes are marine annelid worms that can contribute to aquaculture diversification. Its culture has been viable, and commercially attempted, but intensive production has progressed only in few countries around the world. In the countries with no production, marine polychaetes are imported or harvested. A strong and sustained research investment provided to a better understanding of the nutritional requirements and reproduction of some species. Recent studies showed new technical improvements, which can lead to an important progress in productivity and give a new impetus to the polychaete production. Some marine worm species were identified as good candidates for integrated multitrophic aquaculture. The development of cost-effective aquaculture techniques for marine annelid worms is essential to ensure a balance between commercial interests and the preservation of ecosystems. The influence of polychaete aquaculture on the environment and vice versa raise important concerns related to ecological security and sustainability of this activity. This review focus on the main technical improvements and advances that have been made in areas as diverse as: aquaculture potential of polychaetes, reared species, main species used worldwide, and highlights biological and ecological concerns, important challenges and recommendations.
- Polychaete annelids as live bait in Portugal: harvesting activity in brackish water systemsPublication . Cabral, Sara; Alves, Ana Sofia; Castro, Nuno; Chainho, Paula; Sá, Erica; Fonseca, Luís Cancela da; Costa, Pedro Fidalgo e; Castro, João; Canning-Clode, João; Pombo, Ana; Costa, José LinoPolychaete annelids are some of the most heavily harvested invertebrates collected in coastal areas and estuaries for their economic value as live fishing bait or as food supplement in aquaculture activities. However, information on bait digging in Portugal is scarce or incomplete. Thus, the present study aimed at investigating the bait digging activity in the four most relevant brackish water systems in Portugal: Ria de Aveiro and Ria Formosa coastal lagoons and Tagus and Sado estuaries. Direct observations were performed in each brackish water system 1 h and a half before and after the diurnal low spring tide (< 0.8m height), on working days. Additionally, logbooks were delivered to bait diggers and two types of surveys were conducted in every system: one to all the intertidal users and the other only to bait diggers. The estimated daily weighted number of bait diggers varied between 31 in the Tagus estuary and 69 in the Ria Formosa coastal lagoon. Diopatra neapolitana (Delle Chiaje, 1841) was the main target species in Ria de Aveiro (more than 83%), Tagus estuary (more than 60%) and Ria Formosa (more than 90%), while in Sado estuary most of the bait diggers targeted Marphysa sp. (92.6%). The highest and lowest amount of polychaete annelid catches were estimated for Ria de Aveiro coastal lagoon (almost 50 tons per year) and Tagus estuary (11 tons per year), respectively. A total annual bait catch value in these four systems was estimated as €3.84 millions. The most important brackish water systems concerning bait diggers’ number and bait captures were Sado estuary and Ria de Aveiro coastal lagoon where management measures should be considered, although managing polychaete harvesting activity is still difficult due to limited information on harvesting and on direct and indirect impacts on population dynamics.
- Trade of live bait in Portugal and risks of introduction of non-indigenous species associated to importationPublication . Sá, Erica; Costa, Pedro Fidalgo e; Fonseca, Luís Cancela da; Alves, Ana Sofia; Castro, Nuno; Cabral, Sara dos Santos; Chainho, Paula; Canning-Clode, João; Melo, Pedro; Pombo, Ana Margarida; Costa, José LinoDifferent invertebrate groups are often exploited on sediment shores and mudflats, including polychaetes, sipunculids, bivalves and crustaceans. The commercial importance of polychaetes and sipunculids, that has increased in the early 2000's because of its use as a food source for the aquaculture sector and a growing demand of worms for use as sea angling bait, seems to be declining nowadays. In Portugal bait harvesting from natural populations became insufficient to meet market demands and as a result, polychaetes and sipunculids have been imported in recent years. Due to this it was important to know the ways of the live bait import to Portugal, and to assess the risk of introduction of non-indigenous species associated to that live bait trade. The origin and quantities of imported live bait were determined by examining the landing's records at Lisbon airport, from two periods: 2002e2003 and 2012 e 2015. Live worms imported to Portugal arrived almost exclusively from China, USA and Vietnam. Monthly import data and bait registers at fish auction landings were significantly correlated, showing that bait captures and imports are directly related to higher bait demand. In addition, the risk of live bait's importation as an introduction vector for non-indigenous species was evaluated by examining the bait boxes content. Five worm species were identified in bait boxes with foreign species: Glycera dibranchiata, Namalycastis rhodochorde, Perinereis cultrifera, Perinereis linea, and Sipunculus (Sipunculus) nudus. The examination of bait boxes in Portugal suggested that there is a low risk of associated hitchhiker species introduction and dissemination, mostly because of packaging procedures, which should be advised. The same is not true to the non-indigenous live bait species.