Macrofaunal communities of threatened subtidal maërl seabeds on Tenerife (Canary Islands, north-east Atlantic Ocean) in summer

Abstract

This study contributes with the first data on physical and taxonomical structure of macrofaunal assemblages of maërl beds from the Canary Islands. Maërl beds and Cymodocea nodosa meadows of the Canary Islands are considered biodiversity hot-spots in terms of taxonomic and functional biodiversity with a broad geographical and depth ranges. The authors have studied the structure of the macrofaunal assemblages on different habitat types (Cymodocea, Caulerpa, sabellid field, garden eel and maërl beds). Samples were taken at a range of depths between 14 and 46 m. Correlations were performed among abiotic variables (granulometry, organic matter, nitrogen and phosphates) and the most abundant taxa. Similarity analysis was performed to explore the patchiness of seabeds at a local scale. Significant differences were found in macrofaunal assemblages among seabed types, with highest abundances and lowest biodiversity in sabellid fields, where the sabellid Bispira viola dominated. The polychaetes Aponuphis bilineata and Chone filicauda and the mollusc Turritella brochii were the most abundant taxa on maërl beds. The mosaic of granulometric conditions would explain the associated macroinfaunal community structure and contribute to the creation of diversity on these relatively well preserved seabeds at a local scale.

Diversity, distribution and ecology of benthic molluscan communities on the Portuguese continental shelf

“…Algae or seagrass meadows, maërl and other hard substrate types tend to be richer in species than soft-bottoms (e.g. Riera et al, 2012;Urra et al, 2013). The lower species richness recorded in those works compared to the present study, may be related to the area sampled, which was much bigger in this work covering six latitudinal degrees.…”

“…Antoniadou et al, 2005;Grall and Hall-Spencer, 2003;Riera et al, 2012). Maërl beds, which correspond to accumulations of dead and live unattached coralline algae, such as Phymatolithon calcareum, supports a highly diverse community having a relevant ecological and economic importance, namely mollusks, which are commercially exploited (Grall and Hall-Spencer, 2003 and OSPAR, this is one of the most threatened marine habitats of Europe (Riera et al, 2012). The highest molluskan diversity and abundance was recorded in the coarse sediments of the western Portuguese shelf.…”

Megabenthic communities of the Ligurian deep continental shelf and shelf break (NW Mediterranean Sea)

“…Finally, habitats dominated by B . viola are only known from the Canary Islands [106]. Sabellid beds resembling those of Community 12 have also been reported from a detrital bottom at 90 m depth in front of Cap Ferrat (western Ligurian Sea) during the MEDSEASCAN surveys [107].…”

“Egagrópilas” de Valonia: una comunidad compleja en un ecosistema lagunar

“…El poblamiento faunístico asociado a las "egagrópilas" de Valonia se caracteriza por unos niveles elevados de diversidad, en términos de grupos faunístico (9 filos) y de especies (48 taxones), entre las que dominaron omnívoros de carácter oportunista, como el poliqueto Eurythoe complanata o detritívoros, como los poliquetos Cirriformia tentaculata y Protoaricia oerstedii, el molusco Tricolia pullus canarica y el tanaidáceo Condrochelia dubia. Las "egagrópilas" proporcionan un sustrato y un alimento que permite el asentamiento de ciertas especies que no dominan en los fondos arenosos canarios (Riera et al, 2012(Riera et al, , 2013, caracterizados por una biomasa baja y una riqueza específica inferior. De hecho, cada "egagrópila" constituye una pequeña comunidad en sí misma, en la medida en que contiene todos los niveles tróficos y funcionaría de forma autosuficiente desde el punto de vista energético.…”