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Instituto Español de OceanografíaVersión del editor0,000

El Cachuchu, bayura y biodiversidá nel monte submarín d’Asturies

Academia de la Llingua AsturianaEn prens

A new species of Isodictya (Porifera: Poecilosclerida) from the Southern Ocean

We discovered a new species of Porifera belonging to the genus Isodictya Bowerbank, 1864 during cruises aboard R/V Hesperides in Antarctica. Collected samples are mostly part of the surveys of the Spanish project BENTART whose main objective has been to study the benthic communities inhabiting sea bottoms of Livingston and Deception Island in the South Shetlands archipelago and the Antarctic Peninsula. Isodictya filiformis sp. nov., described here, is characterized by its fragile and thin morphology (very different from other known species in the area) and by having microxeas as additional microscleres. Three specimens were collected from Marguerite Bay, Low Island and Deception Island (Antarctic Peninsula) and one specimen at Peter I Island (Bellingshausen Sea). Its presence in Peter Island is quite relevant as this location is 390 km away from the nearest coast in the Bellingshausen Sea, an area that has scarcely been investigated in the past. However, results from the Bentart 03 Expedition seem to indicate that Peter I Island has a wide variety of benthic organisms, in contrast to the deep adjacent areas of Bellingshausen Sea. Apart from the morphological analyses, we place the new Isodictya species within its phylogenetic context using two nuclear markers (18S rDNA and 28S rDNA) and provide some information about the ecological preferences of the new speciesPostprint1,44

Increasing knowledge of biodiversity on the Orphan Seamount: a new species of Tedania (Tedaniopsis) Dendy, 1924

A new Tedania species (Porifera) was collect using remotely operated vehicles during the Canadian mission HUD2010-029 and the British RRS Discovery Cruise DY081, on the Orphan Seamount near the Orphan Knoll, northwest Atlantic, between 2999.88 and 3450.4 m depth. Orphan Knoll is an isolated, drowned continental fragment 550 km northeast Newfoundland in the Labrador Sea. This region is biologically rich and complex and in 2007, the regional fisheries management organization operating in the area regulated that no vessel shall engage in bottom-contact fishing activities until reviewed in 2020 with a review slated at the end of this year. Members of the genus Tedania are uncommon in the temperate northern hemisphere with only six species known previously: Tedania (Tedania) anhelans; Tedania (Tedania) pilarriosae; Tedania (Tedania) suctoria; Tedania (Tedania) urgorrii; Tedania (Tedaniopsis) gurjanovae; and Tedania (Tedaniopsis) phacellina. The particular features of the new sponge we describe are the very peculiar external morphology which is tree-like with dichotomous branching—a morphology not previously described in this subgenus; and the combination of spicules found: long styles, the typical tornotes of the subgenus and two sizes of onychaetes. Additional information is provided on other species of Tedaniopsis described from the Atlantic Ocean. Based on the characteristics reported, we propose a new species, Tedania (Tedaniopsis) rappi sp. nov. in honor of Prof. Hans Tore Rapp (1972–2020), University of Bergen, Norway, a renowned sponge taxonomist and coordinator of the Horizon 2020 SponGES project. The holotype of T. (T.) phacellina Topsent, 1912 from the Azores, the only other northern Atlantic species in the subgenus Tedaniopsis, was reviewed for comparison.Postprin

High resolution spatial distribution for the hexactinellid sponges Asconema setubalense and Pheronema carpenteri in the Central Cantabrian Sea

In the present work we focus on the distribution of two species of sponges. One of these is Asconema setubalense, a sponge found in rocky substrate that was sampled with a photogrammetric vehicle through georeferenced images. The other is Pheronema carpenteri, which inhabits soft bottoms and was sampled by beam trawl. For the spatial distribution modeling of both sponges, the geomorphological variables of depth, slope, broad and fine scale bathymetric position index (BPI), aspect, and types of bottoms were used, all with a resolution of 32 m. Additionally, layers of silicates and currents near the bottom were extracted from Copernicus Marine Environment Monitoring Service (CMEMS), with a resolution of 4 and 9 km, respectively. Due to the low resolution of the layers, it was considered necessary to validate their use by model comparison, where those that included these variables turned out to be more explanatory than the others. The models were developed in a complex continental break of the Central Cantabrian Sea, which comprises several submarine canyons and a seamount (Le Danois Bank). On the one hand, a very high resolution (32 m) spatial distribution model based on A. setubalense presence was developed using the MaxEnt maximum entropy model. On the other, depending on the availability of density data, generalized additive models (GAMs) were developed for P. carpenteri distribution, although in this case the sampler only allowed a maximum resolution of almost 1 Km. For the A. setubalense, the variables that best explained their distribution were ground types and depth, and for P. carpenteri, silicates, slope, northness, and eastward seawater velocity. The final model scores obtained were an AUC of 0.98 for the MaxEnt model, and an R squared of 0.87 for the GAM model.Postprin

In-situ growth rate assessment of hexactinellid sponge Asconema setubalense using 3D photogrammetric reconstruction

We describe the first application of a non-invasive and novel approach to estimate the growth rate of Asconema setubalense (Porifera, Hexactinellida) through the use of 3D photogrammetric methodology. Structure-from-Motion techniques (SfM) were applied to videos acquired with the Politolana ROTV in the El Cachucho Marine Protected Area (MPA) (Cantabrian Sea) on three different dates (2014, 2017, and 2019) over six years. With these data, a multi-temporal study was conducted within the framework of MPA monitoring. A complete 3D reconstruction of the deep-sea floor was achieved with Pix4D Mapper Pro software for each date. Having 3D point clouds of the study area enabled a series of measurements that were impossible to obtain in 2D images. In 3D space, the sizes (height, diameter, cup-perimeter, and cup-surface area) of several A. setubalense specimens were measured each year. The annual growth rates recorded ranged from zero (“no growth”) for a large size specimen, to an average of 2.2 cm year�����1 in cup-diameter, and 2.5 cm year�����1 in height for developing specimens. Von Bertalanffy growth parameters were estimated. Taking into account the size indicators used in this study and based on the von Bertalanffy growth model, this sponge reaches 95% maximum size at 98 years of age. During the MPA monitoring program, a high number of specimens disappeared. This raised suspicions of a phenomenon affecting the survival of this species in the area. This type of image-based methodology does not cause damage or alterations to benthic communities and should be employed in vulnerable ecosystem studies and MPA monitoring. Keywords: underwater photogrammetry, Asconema setubalense, Marine ProtectedPostprin

Diversidad de holoturoideos (Echinodermata:Holothuroidea) de la costa y plataforma continental de Asturias

Desde la década de los 70 se ha venido recolectando y conservando en la Colección del Departamento de Biología de Organismos y Sistemas (BOS) -Zoología-, macrofauna procedente de muestreos periódicos realizados en la zona intermareal de distintas localidades de la costa de Asturias (ría del Eo, Tapia de Casariego, Luanco, Gijón y Villaviciosa). Las tres localidades muestreadas más regularmente fueron Aramar (Luanco) -sustrato rocoso-, El Rinconín (Gijón) –sustrato rocoso- y El Puntal y La Ermita (Ría de Villaviciosa) -sustrato blando- Entre la fauna recolectada se encontraron numerosos ejemplares del grupo de los holoturoideos, pertenecientes a los órdenes Apodida, Aspidochirotida y Dendrochirotida. En este trabajo se presentan datos sobre la diversidad de holoturoideos depositados en la colección del Departamento BOS procedentes de las localidades anteriormente mencionadas, así como del material procedente de las costas de la península Ibérica y de los archipiélagos Atlánticos de las islas Canarias y Cabo Verde. La identificación de especies se ha basado en la morfología externa, pero, sobre todo, en la extracción de escleritos dérmicos y el estudio de su forma, tamaño y distribución, lo cual tiene una mayor importancia como carácter taxonómico para la correcta determinación de las especies que la apariencia externa. Finalmente, se presenta un listado actualizado de los holoturoideos registrados para las costas de Asturias, basado en datos propios y bibliográficos procedentes de las campañas oceanográficas “Cantábrico 83” y “CAP-89” realizadas en la plataforma costera cantábrica (López-Ibor A. 1987; De la Hoz J.J. & García L. 1991)

Community composition and habitat characterization of a rock sponge aggregation (Porifera, Corallistidae) in the Cantabrian Sea.

Deep-sea sponge-dominated communities are complex habitats considered hotspots of biodiversity and ecosystem functioning. They are classified as Vulnerable Marine Ecosystem and are listed as threatened or declining as a result of anthropogenic activities. Yet, studies into the distribution, community structure and composition of these habitats are scarce, hampering the development of appropriate management measures to ensure their conservation. In this study we describe a diverse benthic community, dominated by a lithistid sponge, found in two geomorphological features of important conservation status —Le Danois Bank and El Corbiro Canyon— of the Cantabrian Sea. Based on the analyses of visual transects using a photogrammetric towed vehicle and samples collected by rock dredge, we characterize the habitat and the associated community in detail. This deep-sea sponge aggregation was found on bedrock. It is dominated by one lithistid sponge, Neoschrammeniella aff. bowerbankii (0.2 ind./m2) and further composed of various sponge species as well as of other benthic invertebrates such as cnidarians, bryozoans and crustaceans. Using a non-invasive methodology (SfM – Structure from Motion) and empirical relationships of individuals size and biomass/volume obtained in laboratory for N. aff. bowerbankii, we were able to estimate a total biomass of 41 kg and volume of 39 l of this species in the surveyed area. This approach allows a fine tune methodology for estimating biomass and volume by image-based-observed area avoiding destructive techniques for this species.Postprin

A Case Study of available methodology for the identification of Vulnerable Ecosystems/Habitats in bottom deep-sea fisheries: Possibilities to apply this method in the NAFO Regulatory Area in order to select Marine Protected Areas

Information is critical to Ecosystem Approach and to research about Vulnerable Marine Ecosystems/Habitats (VME/Hs), fishing impacts on habitats and ad-hoc management measures are high-priority. Therefore, this paper presents the ECOVUL/ARPA Interdisciplinary Approach, a case study of methodology for the identification of VME/Hs in order to advise on conservation measures such as marine protected areas (MPAs). By means of an interactive process involving Conventional Fisheries Science, Geomorphology, Sedimentology and Benthic Ecology, the methodology developed under the ECOVUL/ARPA project, has been useful in order to contribute to define practical criteria to the identification of VME/Hs, to improve the knowledge about VME/Hs distribution and the adverse impacts of bottom trawl fisheries and to produce high quality advice on habitat protection. Applying an interdisciplinary approach, the project identified the deep-water bottom trawl fishery footprint on the Hatton Bank Western slope (NEAFC Regulatory Area), mapped the main fishing grounds and related seabed habitats and studied the interactions between fishing and cold-water corals. This approach was used to suggest, with high level of precision, the spatial limits of an area closed to bottom fishing, as an essential conservation measure to protect the cold-water corals in the framework of the Ecosystem Approach to Fisheries management. We present here the methods used, the main results obtained and discuss on the utility of this approach and the possibilities to apply it in the NAFO Regulatory Area, with the aim to advise on measures for reducing the interactions of bottom fishing with sensitive high-seas habitats and to contribute to implement the UNGA recommendations about habitat conservation

Mapping the habitats of a complex circalittoral rocky shelf in the Cantabrian Sea (south Bay of Biscay)

This work focuses on the study of habitats and communities of a high structural complexity area at different levels and scales. This gives us a better understanding of an area from an ecological point of view and at the same time provides us with tools that will facilitate management measures. It was developed in a complex circalittoral rocky platform of the central Cantabrian Sea (Bay of Biscay). The sampling was carried out using a towed photogrammetric vehicle and a rock dredge, which was used for the identification of the species. The first level of the study was the abiotic characterization of the area and the analysis of the communities. These analysis were developed using the unsupervised k-means classification method. For abiotic characterization we used the variables directly associated with the composition and morphology of the ground, such as backscatter, BPI (Bathymetric Position Index), roughness and slope. Depth was also included to discriminate between the circalittoral and bathyal zones. We obtained 5 different classes, which we related to the ground types observed by photogrammetry. In the analysis of the communities, the cluster was based on the sampling units extracted from the images (~10 m), from which 5 assemblages were obtained, providing information on the most abundant species of each class supplied by the abiotic study. The second level was carried out considering a management approach and was based on the modeling of the area at lower resolution, more suitable for the analysis of the habitat-fisheries interactions. Thus, the main habitat-forming species (HFS) of the entire circalittoral area were used to perform delta models based on GAMs (Generalize Additive Models). Obtaining the predictions of presence/absence and combining it with the predictions of densities, we got the zero inflated values density-based model. As all the identified habitats have vulnerable benthic species of a certain size settled on rocky bottoms, they can all be considered to belong to the designation 1170 reefs of the Habitats Directive