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- The effect of temperature on somatic and gonadal development of the sea urchin Paracentrotus lividus (Lamarck, 1816)Publication . Santos, Pedro M.; Albano, Pedro; Raposo, Andreia; Ferreira, Susana M. F.; Costa, José L.; Pombo, AnaThe common sea urchin Paracentrotus lividus (Lamarck, 1816) is the most consumed echinoid in Europe. It is considered a seafood delicacy, given its high-valued gonads. In sea urchins, temperature probably represents the most important abiotic factor affecting several physiological processes and it is essential to better establish optimal reference conditions for aquaculture. In this study, four rearing temperatures (18 °C, 20 °C, 22 °C and 24 °C) were tested in wild-caught adult P. lividus, from the west coast of Portugal. The animals were fed an agarbased artificial diet, over a period of 90 days. The effect of temperature was tested in terms of test diameter and total wet weight, feed intake, gonadosomatic index (GI) and reproductive development. Thus, linear growth rate (mm month−1), daily growth rate (% day−1), total wet weight gain (mg ind.−1 day−1) and total feed intake (g day−1 ind.−1) of sea urchins were calculated at the end of the trial. Although feed intake was relatively similar between groups, the results showed a consistent response for biometric parameters regarding the different temperatures regimes. The rearing temperature of 22 °C promoted the highest test diameter (.53 mm month−1) and total wet weight (47 mg ind.−1 day−1) growth. Sea urchins from the same group (22 °C) presented the highest final GI of 9.3%, a 163.5% increase in comparison to the initial value, after the fasting period (3.5%). This temperature also promoted the highest gonad maturation levels, both in males and females. Although increasing temperatures (until 22 °C) generally produced favourable rearing results, the 24 °C regime led to lower somatic and gonadal growth, plus slower gonad maturation results. Overall, P. lividus fed with a formulated diet and reared at 20–22 °C, showed considerable somatic and gonadal growth, as well as a significant sexual maturation, which will allow to obtain developed gonads and gametes all year round. On the other hand, 18 °C promoted a slower progression in the gametogenic cycle, which may contribute to produce gonads with better organoleptic properties for human consumption.
- Morphometric approach to the development of Paracentrotus lividus larvae fed with different microalgae dietsPublication . Lourenço, Sílvia; Gomes, Ana Sofia; Santos, Pedro M.; Raposo, Andreia; Ferreira, Susana; Pombo, Ana
- Sandy beach macrofaunal communities on the western coast of Portugal – Is there a steady structure under similar exposed conditions?Publication . Gonçalves, Sílvia C.; Anastácio, Pedro M.; Pardal, Miguel A.; Cardoso, Patrícia G.; Ferreira, Susana M.; Marques, João C.; Gonçalves, Sílvia; Ferreira, SusanaThe structure of macrofaunal communities at two similar exposed sandy beaches on the western coast of Portugal was monitored for approximately 18 months by sampling all the beach area, from the shoreline to the base of the dunes. The beaches' physical environment, as well as community density and composition, seasonal variations and the potential relationships between biological data and environmental parameters were studied. The two beaches had similar exposure to wave action, but differed in terms of sediment grain size, extent of the intertidal area, sediment moisture content and, especially, in the potential food availability in the form of allochthonous debris. Differences were observed with regard to the communities' structure, namely regarding composition and relative contribution of the dominant species. Seasonality, especially temperature variations, and the interaction between seasons and the beach zones (supralittoral vs. intertidal) also had a strong influence on communities: controlling dominant species' density and the horizontal distribution of the dominant species, and promoting a differential utilization of the beach by several resident macrofaunal animals. The present study allows the identification of key species in exposed sandy beaches of western Portugal and demonstrates that a steady community structure does not persist in the similarly exposed conditions observed, which may be mainly a response to distinct detritus subsidies, combined with differences in sediment grain size, sediment moisture content and extent of the intertidal area.
- A morphometric approach to the development of Paracentrotus lividus larvae fed with different microalgae dietsPublication . Lourenço, S.; Gomes, A.S.; Santos, Pedro Castelo Filipe Moreira dos; Raposo, A.; Ferreira, S.M.F.; Pombo, AnaParacentrotus lividus is the most valuable sea urchin species in the European roe markets. Its economic value has been driving an intense exploration of wild populations leading to their over-exploitation in several areas of the Mediterranean and eastern Atlantic coast. The full production of P. lividus in aquaculture can potentially supply the European market for sea urchin roe reducing the impact over the wild populations. However, the low survival rates of sea urchin planktonic stages represent a critical bottleneck for the full cycle production for commercial purposes. Together with the zootechnical challenges, the selection of a suitable microalgal diet is fundamental to overcome this challenge. In the present study, we conducted two larvae rearing experiments testing the effect of five microalgae diets in the larvae development, age at competence and survival. The experimental diets tested were: Rhodomonas baltica (rho); Phaedactylum tricornutum (phae); Chaetoceros calcitrans (chae); a mix diet of rho and phae (1:1); and a mixed diet of rho and chae (1:1). The larvae were reared in closed system in triplicate tanks (50 L) at a density of 4 larvae/mL with seawater temperature ranging between 18.5 and 20°C. The daily feed concentration was adapted to the larval stage of development and standardized to the ratio between microalgae biovolume. Larvae samples were regularly collected to measure larvae body length, body width, post-oral arm length and the rudiment length. Linear models were fitted to the larval measurements and the model residuals were analyzed as an indication of larvae body condition. The larval survival was assessed volumetrically every two days. The results showed that the larvae fed with rho attained age at competence (at 18 days post fecundation, DPF, in experiment I and at 16 DPF at experiment II) earlier than larvae fed with phae, chae or with the mixed diets. On the other hand, the larvae fed with the rho and chae mixed diet presented higher survival rate (32 %). Moreover, the preliminary analysis of the linear model residuals showed that the mixed diet promoted the development of larvae with better condition. These results indicated that the rho diet promoted a reduction of the planktonic phase albeit with costs in terms of larval condition and survival rate.
- Is the plant Bolboschoenus maritimus an adequate biomonitor for trace metal contamination in saltmarshes? A field study from the Óbidos lagoon (Portugal)Publication . Santos, Márcia S.S.; Pedro, Carmen A.; Ferreira, Susana M. F.; Gonçalves, Sílvia C.Monitoring the negative impacts of trace metals is crucial to assess the health and stability of ecosystems. In salt marshes, halophyte plants were reported as possible bioaccumulators of these elements. The aim of this work was to explore the bioaccumulation potential of Bolboschoenus maritimus as a tool for monitoring the presence of metals in coastal environments. Bolboschoenus maritimus were collected from a brackish water lagoon, and the presence of the trace metals lead, cadmium, and nickel were seasonally evaluated in distinct parts of the plants, and in water and sediment samples. Lead was the trace metal with the highest concentration detected in water and sediments of the sampling site. The highest lead concentrations in B. maritimus were recorded in the spring season. The transport index indicated an accumulation of lead in the leaves of around 70% in the spring of 2009. Cadmium in leaves in spring and summer of 2009 reached values above 5 mg Cd. kg−1. Nickel was not detected in most samples collected. Bolboschoenus maritimus was considered an adequate biomonitor for lead and cadmium, since it bioaccumulates both metals with seasonally distinct results, as the bioaccumulation factor results indicated.
- 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.
- Monitoring metal pollution on coastal lagoons using Cerastoderma edule: a report from a moderately impacted system in Western Portugal: Óbidos LagoonPublication . Veiga, Kelly; Pedro, Carmen A.; Ferreira, Susana M. F.; Gonçalves, Sílvia C.The main goal of this monitoring program was to evaluate the contamination in the intertidal environment of Óbidos Lagoon by the metals Cd, Pb, and Ni on water, sediments, and on biological samples, using the bivalve Cerastoderma edule (common name: cockle) as a biomonitor. Since C. edule is an edible mollusc, the risk of their consumption by humans from this lagoon was also evaluated. The study was performed in a restricted area of the lagoon—the MLstation—where human activities, such as shellfish harvesting, intersect with the natural processes occurring in this system. The results obtained revealed that the water samples were polluted with Cd and Pb with concentrations (0.00025 mg l−1 and 0.0072 mg l−1) above the maximum legislated on the Directive 2008/105/EC, while for Ni, this occurred only on one of the seasons sampled (summer 2010: 0.029 mg l−1). The sediments were not contaminated with Cd and Ni, and the contamination detected for the metal Pb, allowed the classification of this station as an unpolluted site ([Pbmin] = 7.477 mg.kg−1 and [Pbmax] = 19.875mg.kg−1). On biological samples, comparing the results of metal contaminations with the values of the maximum levels fixed by European Commission Regulation (EC) No 1881/2006 and USFDA, all the results were below the legal value. Therefore, during the period of study, the consumption of this bivalve by humans was safe. Also, BAF and CF calculations suggest that C. edule can be used as a biomonitor to determine the source of the contaminations. This study supported the use of C. edule as a biomonitor to assess the contamination by the metals Pb and Ni at the Óbidos Lagoon and allowed to predict the potential transfer of metals to higher trophic levels with potential impacts on the natural and human communities.
- 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.
- Somatic growth and gonadal development of Paracentrotus lividus (Lamarck, 1816) fed with diets of different ingredient sourcesPublication . Lourenço, Sílvia; Cunha, Beatriz; Raposo, Andreia; Neves, Marta; Santos, Pedro M.; Gomes, Ana S.; Tecelão, Carla; Ferreira, Susana M. F.; Baptista, Teresa; Gonçalves, Sílvia C.; Pombo, AnaSea urchins’ gonads are a delicacy highly appreciated worldwide. In Europe, Paracentrotus lividus is one of the most valuable edible sea urchin species and a desired target for aquaculture. One of the challenges of echinoculture is to increase the sea urchins’ growth rate during the on-growing phase and reducing the production cycle required to obtain sea urchins of commercial size (test diameter ≈ 50 mm). The present study aimed to evaluate the growth and gonad development of P. lividus urchins fed with three dry diets for 15 weeks. The diets were formulated with ingredients of three different sources: an algae-based, a fishmeal-based and a cereals-based diet. The somatic growth was assessed by biometric indicators like the linear and specific growth rates. The gonadal development was assessed by the gonadal somatic index (GSI), gametogenesis level, proximate composition and fatty acids profile. The results obtained showed high growth rates in all the three diets tested (0.44% per day). The sea urchins fed with the cereals diet presented the highest GSI (8.22%) with higher proportion of gonads in growing and premature stages. The proximate composition of the sea urchins’ gonads was significantly affected by diet and sea urchins’ sex, particularly the lipid content. Concomitantly, fatty acids (FA) profile of the gonads was influenced by both diet and sea urchins’ sex with saturated and polyunsaturated FA playing an important role in this differentiation.
- Effects of single and mixed-diatom diets on growth, condition, and survival of larvae of the sea urchin Paracentrotus lividus (Lamarck, 1816)Publication . Gomes, Ana; Lourenço, Sílvia; Santos, Pedro M.; Raposo, Andreia; Mendes, Susana; Gonçalves, Sílvia C.; Ferreira, Susana M. F.; Pombo, AnaThe development of rearing protocols promoting the larval development, pre and postmetamorphosis are key for echinoculture. Mixed diets combining diatom with other microalgae have been used with success and Rhodomonas sp. (Rho)-based diets showed promising results in larval survival. This study was aimed to evaluate the rearing success of Paracentrotus lividus larvae fed with mixed diets combining Rho with two diatoms, Phaedactylum tricornutum (Phae) and Chaetoceros calcitrans (Chae) in two experiments. In experiment I, the effect of the mixed diet of Rho and Phae (Mix I) was compared with monospecific diets of both species, while in experiment II, Rho was combined with Chae (Mix II) and compared with both monospecific diets. In experiment I, larvae fed with Rho I and Mix I diets grew faster than larvae fed with Phae I diet, attained the competence earlier with survival rates of 15-16%. In experiment II, the larvae fed with Rho were larger and the larvae fed with Mix II attained the highest survival rate (32.22%). The analysis of the larval biometric models showed that the larger larvae, with bigger stomachs, and shorter post-oral arm attained the age-at-competence earlier with higher survival rates. In conclusion, the larvae fed with a combination of Rho with the selected diatoms showed identical growth performance and condition to larvae fed with Rho monospecific diet but obtained higher survival rate. These results indicate that mixed-diatoms diets may be more suitable for P. lividus larval rearing.