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- Pilot studies for stock enhancement of purple sea urchins (Paracentrotus lividus, Lamarck, 1816): usefulness of refuges and calcein marking for the monitoring of juveniles released into the natural environmentPublication . Correia, Maria João; Lopes, Patrícia Mega; Santos, Pedro M.; Jacinto, David; Mateus, David; Maresca, Francesco; Quintella, Bernardo Ruivo; Cruz, Teresa; Lourenço, Sílvia; Pombo, Ana; Costa, José LinoIn the framework of stock enhancement, field experiments were conducted between March and July 2021 in rocky shores of Central Portugal to test the usefulness of refuges and calcein marking for juvenile sea urchins releases. Individuals with 10–20mmin test diameter were captured in nature and tagged through immersion in a calcein bath with a concentration of 150 mg L 1, during 48 hr. Artificial shelters were used to provide refuge and an acclimatization structure for the released sea urchins, and in situ monitoring was carried out by counting the marked specimens over three months. Results point out to the importance of using shelters to provide protection to sea urchins, and validated the efficiency of the calcein tagging protocol for in situ monitoring. Sea urchins’ test diameter growth during the experiment was estimated to be 0.470mm month 1 (SD = 0.181).
- Preliminary deep-sea data analysis collected at Gloria seamount, Azores-Biscay RisePublication . Tojeira, Inês; Pinto-Ribeiro, Luísa; Rafael, Teresa; Albuquerque, Mónica; Simões, Maria; Calado, António; Afonso, Andreia; Ramos, Bruno; Souto, Miguel; Bettencourt, Renato; Vasco Rodrigues, Nuno; Costa, José Lino; Cabral, Henrique; Madureira, PedroThe present study provides the first results of the exploratory research campaign to Gloria seamount (summit at 45.03°N, 15.54°W), a newly identified seamount in the NE Atlantic. New multibeam bathymetry and an 8 h remote operated vehicle footage and photography data were compiled and analyzed to give the first insights on the geological nature and benthic megafauna assemblages of Gloria seamount. Footage evidenced three distinct seafloor coverage areas, ranging from unconsolidated fine sediment with ripple marks, to increasingly coarser-grain sediment with large blocks, to outcrops with steep slopes along successive ridges, locally exhibiting volcanic structures. The deep-sea benthic assemblages differed with depth (2700−2450 m) and seafloor substrate type. In sediment habitats, pink holothurians (Elpidiidae) and brittle stars (Ophiuroidea) were recorded, whereas in hard substrates, sponges (Hexactinellida and Demospongiae) and stalked crinoids (Crinoidea) were mixed with distinct coral specimens, such as bamboo corals (Isidiidae) and Coralliidae (Scleralcyonacea). The integration of these data contribute to the geo-habitats knowledge of an unexplored seamount.
- Reproductive Cycle of the Sea Urchin Paracentrotus lividus (Lamarck, 1816) on the Central West Coast of Portugal: New Perspective on the Gametogenic CyclePublication . Raposo, Andreia; Ferreira, Susana M. F.; Ramos, Rodolfo; Anjos, Catarina; Gonçalves, Sílvia C.; Santos, Pedro M.; Baptista, Teresa; Costa, José L.; Pombo, AnaA population of sea urchins, Paracentrotus lividus, from the central west coast of Portugal was studied to characterise their reproductive biology and possible relationships with environmental factors. An annual gametogenic cycle was found, with a broad spawning season, from May to November, according to a relatively synchronous gamete maturation process. Depending on the environmental factors (temperature, photoperiod), two separate periods could be distinguished, with more individuals maturing and spawning at the same time. When this happened, the first event evolved when temperature rose to a critical point, and the second occurred afterwards, when temperature decreased significantly. Notwithstanding, it was found that individuals matured later than previously described for other populations (e.g., north of Portugal), mostly in late spring, with a higher gonadosomatic index in May. A new classification scale was proposed for identifying the stages of P. lividus gametogenic cycle, based on new findings. It contributed to its simplification and easier comprehension. This study provides useful information for a differentiated sustainable management of P. lividus, according to local conditions. Establishing a closed harvesting season might be considered, based on the differences observed between Portuguese populations and other European ones.