181 research outputs found
La Reserva Marina de la Isla de Tabarca, una realidad después de un sueño
La Reserva Marina de Tabarca se creó en abril de 1986 por el Ministerio de Agricultura, Pesca y Alimentación y la Conselleria de Agricultura i Pesca de la Generalitat Valenciana, a solicitud del Ayuntamiento de Alicante. Su creación se fundamentó en un componente científico (especies, hábitats, cartografía de los fondos), socio-económico (usos tradicionales como pesca y turismo) y legislativo (principalmente, en la normativa pesquera vigente). Tabarca se organizó como un área marina protegida de múltiple-uso, con áreas de diferente nivel de protección y de gestión (estricta, experimentación, pesquería artesanal, turismo)
A striking morphotype of Aplidium proliferum (Milne Edwards, 1841) (Ascidiacea: Polyclinidae) from the Strait of Gibraltar
An unusual colonial ascidian with 1-2m in length, belonging to the genus Aplidium (Ascidiacea: Polyclinidae), has been sampled from the Strait of Gibraltar (Ras Leona, Morocco). The characteristics of the colony, zooids and larvae point us to A. proliferum. The species seems common in the NE Atlantic from the Shetland Islands to Mediterranean Sea, but it never has observed the size of colonies as found in this area, the Strait is the largest so far reported, which it is probably represents one of the longest ascidian worldwide.The first observations (2009) were made thanks to a grant from the Spanish Agency for International Cooperation and Development (AECID: A-016248/08)
Grazing on the seagrass Posidonia oceanica in the Marine Reserve of Tabarca, Spain
Fluctuaciones en la intensidad del herbivorismo sobre Posidonia
Zoogeographical relationships of the littoral ascidiofauna around the Antarctic Peninsula in the Scotia Arc and in the Magellan region
Three Spanish Antarctic research cruises (Ant-8611, Bentart-94 and Bentart-95) were carried out in the South Shetland Archipelago (Antarctic Peninsula) and Scotia Arc (South Orkney, South Sandwich and South Georgia archipelagos) on the continental shelf and upper slope (10-600 m depth). They have contributed to our knowledge about ascidian distribution and the zoogeographical relationships with the neighbouring areas and the other Subantarctic islands. The distribution of ascidian species suggests that the Scotia Arc is divided into two sectors, the South Orkney Archipelago, related to the Antarctic Province, and the South Georgia Archipelago (probably including the South Sandwich Archipelago), which is intermediate between the Antarctic Province and the Magellan region
Shifts in marine invertebrate bacterial assemblages associated with tissue necrosis during a heat wave
Marine heat waves (MHWs) are periods of extremely high seawater temperature that affect marine ecosystems in several ways. Anthozoans (corals and gorgonians) and Porifera (sponges) are usually among the taxa most affected by MHWs. Both are holobiont entities that form complex interactions with a wide range of microbes, which are an essential part of these organisms and play key roles in their health status. Here, we determine microbial community changes suffered in two corals (Cladocora caespitosa and Oculina patagonica), one gorgonian (Leptogorgia sarmentosa) and one sponge (Sarcotragus fasciculatus) during the 2015 MHW. The microbial communities were different among hosts and displayed shifts related to host health status, with a higher abundance in necrosed tissues of Ruegeria species or of potential pathogens like Vibrio. We also carry out a meta-analysis using 93 publicly accessible 16S rRNA gene libraries from O. patagonica, C. caespitosa and L. sarmentosa to establish a Mediterranean core microbiome in these species. We have identified one Ruegeria OTU that maintained a stable and consistent association with these species, which was also related to tissue necrosis in their hosts. Therefore, Ruegeria sp. could play an important and still underexplored role in the health status of its hosts.This work has been carried out within the CIESM project “Tropical Signals” and it was funded by the European Union’s framework program Horizon 2020 (LEIT-BIO-2015-685474, Metafluidics, to JA)
Reviewing the knowledge on the genus Patella in the Mediterranean Sea: testing the effect of protection on the mean abundance and size of Patella ferruginea
Increasing human pressure has strongly impacted the littoral environment, altering the habitats and population parameters of some species. The Mediterranean Sea is one of the regions that have been highly affected by these events. In response to these events, marine protected areas (MPAs) have emerged as one of the main conservation tools for marine habitats and species. In this regard, harvesting of limpets (Patella spp.) is a good example of the impact of human activity on the coast. Limpets are mollusks that are collected as food or fishing bait, and their exploitation causes an immediate decrease in the density and size structure of individuals. In the Mediterranean Sea, the genus Patella is represented by five species: Patella rustica, P. caerulea, P. ulyssiponensis, P. ferruginea, and P. depressa. To verify the effectiveness of the MPAs, a deep review of 75 studies on Patella spp. in the Mediterranean Sea was conducted to analyze the spatial and temporal distribution of studies. Data extracted from these articles were used to assess the effect of protection on the density and size of P. ferruginea. Regarding spatial distribution, the studies reviewed were performed at 67 sites in 13 countries, of which 23 were in MPAs and 44 in non-protected or control areas. The findings of this study show that P. ferruginea is the species most studied, because it is one of the most threatened marine invertebrates in the Mediterranean Sea. This explains the temporal distribution of the studies, which coincides with the establishment of the conservation status and the concern about the population status of P. ferruginea. Analysis of the effect of protection on the density and mean size of P. ferruginea individuals revealed no significant difference in mean density between the control sites and MPAs. However, mean size between individuals was significantly higher in MPAs than control sites. This pattern may be related to intra- and interspecific competition between individuals
Identificação das espécies de tunicados não indígenas da costa portuguesa
As atividades humanas fizeram com que algumas espécies de ascídias se tornassem NIS, colonizando habitats fora da sua zona de distribuição nativa. A introdução de espécies de ascídias NIS está principalmente relacionada com a importação de bivalves para exploração comercial e através de fouling (incrustação - processo de acumulação indesejada de materiais ou organismos em estruturas antropogénicas como pontões, marinas, embarcações, boias, etc.) de cascos de navios e embarcações. Nomeadamente, a importação de ostras para produção em aquacultura introduziu espécies de ascídias que vinham encrustadas ou fixas às conchas. Sendo as condições ambientais e ecológicas favoráveis, estas espécies NIS conseguem colonizar os habitats onde foram introduzidas e estabelecer nele populações viáveis. A outra forma de introdução é o fouling de cascos de embarcações, onde os organismos se vão reproduzindo e colonizando habitats por onde as embarcações vão navegando, fazendo com que as marinas e portos sejam "berçários" para o desenvolvimento e crescimento de novas populações NIS.Projeto BioMar P
Sipuncula inhabiting the coral Oculina patagonica in the western Mediterranean Sea
Background: We analyzed the sipunculan fauna inhabiting the scleractinian coral Oculina patagonica in the Marine Reserve of Tabarca Island (western Mediterranean). Results: Five sipunculan species were collected from 2011 to 2014: Phascolosoma stephensoni, P. granulatum, P. cf. agassizii, Aspidosiphon misakiensis, and Golfingia vulgaris. All five species were reported for the first time inhabiting O. patagonica; with P. cf. agassizii being a new record for the Iberian Peninsula. The average abundance of sipunculans inhabiting the coral was 468.75 ± 158.04 ind m−2, representing the second most abundant taxonomic group, in biomass, after Mollusca. Conclusions: Sipunculan diversity was low comparing with tropical reefs, but species abundances were higher than in soft-bottom nearby areas and community structure appears to be more homogeneous. There may be a considerable contribution to the erosion of the coral skeleton by sipunculans
Iceland: a laboratory for non-indigenous ascidians
Non-indigenous species (NIS) represent a serious problem worldwide, where ascidians are one of the most important taxa. However, little has been done to document the non-indigenous ascidians in Iceland, and over the past decade only two species had been recorded prior to the present study, Ciona intestinalis in 2007 and Botryllus schlosseri in 2011. To increase the knowledge of this taxon, extensive sampling was carried out in shallow waters around Iceland, during the summer 2018, in ports and on ropes of a long-line mussel aquaculture. In total, eleven species were identified, four native and seven NIS, of which Diplosoma listerianum, Ascidiella aspersa, Botrylloides violaceus, Molgula manhattensis and Ciona cf. robusta, are now reported for the first time in Iceland. The highest abundance of non-indigenous ascidians appeared among the ports in southwestern Iceland (Sandgerði, Hafnarfjörður). As pointed out for other regions, the most likely vector is maritime traffic (hull fouling and ballast water), although other vectors cannot be ruled out. The future expansion of these non-indigenous ascidians around Iceland must be monitored, where local maritime traffic could play an important role. Furthermore, global warming may facilitate the access and establishment of these species in colder areas with arctic influence (north and east of Iceland), which are likely still free of these species.This work was partly supported by the Suðurnes Regional Development Fund under grant no. 34/2017. One of the authors (ARE) received two grants for stays for research staff in foreign centers from the University of Alicante (2018) and from the Generalitat Valenciana (BEST-2019 program)
Effectiveness assessment of an artificial reef off Tabarca Island (Alicante, southeastern Iberian Peninsula)
The efficiency of an artificial reef off Tabarca Island in aggregating a fish assemblage was studied by comparing it with natural rock sea beds and Posidonia oceanica (L.) Delile, 1813 seagrass beds located in the island's marine preserve. A study of the fish assemblage's density, number of species, diversity, and biomass showed that the artificial reef was, in ecological terms, situated between the natural rock grounds and the P. oceanica seagrass bed, with some tendency towards greater similarity to the former as time of submersion increased. Multivariant analysis showed that those variables related to habitat complexity were the most important in structuring the fish assemblage.En el área protegida de la reserva marina de Tabarca (Alicante) se levanta un arrecife artificial construido con módulos alveolares muy abiertos y un relieve vertical de 4,5 m de altura. Su eficiencia se ha estudiado mediante la comparación con fondos de roca natural y de pradera de Posidonia oceanica (L.) Delile, 1813 en condiciones de protección. Del análisis de las variables del poblamiento íctico (densidad, número de especies, diversidad y biomasa) se desprende que el arrecife artificial de Tabarca se sitúa entre los dos tipos de fondos naturales estudiados (roca y pradera), con tendencia a semejarse a los fondos de roca natural según aumenta el tiempo de inmersión de los módulos. El análisis multivariante del poblamiento, en relación con las variables estructurales y ambientales utilizadas, evidencia la mayor importancia de la complejidad del hábitat respecto a otras variables, como la estacionalidad o la temperatura.Instituto Español de Oceanografí
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