Sponge (Porifera) fauna of Frobisher Bay, Baffin Island, Canada with the description of an Iophon rich sponge garden

Abstract

The deep-water sponge fauna of the Canadian Arctic remains to be fully described, particularly in areas that are not sampled by fisheries stock-assessment trawl surveys such as the major bays and fjords of the northern Labrador Sea and Baffin Bay. Frobisher Bay is a large inlet located on the southeast of Baffin Island. We used a remotely operated vehicle, as well as box cores and Agassiz trawls to study the sponge fauna of this bay. Over three years, from 2015 to 2017, sponge specimens were collected representing 24 distinct sponge taxa. Dense gardens of Iophon koltuni Morozov, Sabirov, & Zimina, 2019 were discovered at a site near Hill Island in inner Frobisher Bay. The species has a unique finger-like growth form and provides complex habitat in the inner bay. Other sponge species are new to the Northern Labrador marine ecoregion. In particular, we report geographic range extensions of Tetilla sibirica (Fristedt, 1887) and Craniella polyura (Schmidt, 1870), and provide spicule measurements and descriptions of Iophon piceum (Vosmaer, 1882) and Mycale lingua (Bowerbank, 1866). These species identifications, geographic range extensions, and an expanded description of a species synonym represent the first inventory of the sponge fauna of Frobisher Bay.

Influence of Deep-Water Corals and Sponge Gardens on Infaunal Community Composition and Ecosystem Functioning in the Eastern Canadian Arctic

“…Limiting the deposition of organic matter on the seafloor, sponge gardens at the FB site seem to result in a lower proportion of filter feeders and a lower infaunal density compared to its adjacent habitat. However, large ascidians, crinoids (Heliometra glacialis), sea anemones, drift/detrital kelp and other less represented sponges were abundant around sponge gardens, as previously reported by Dinn et al (2019). Their patchy distributions in bare sediment might also contribute to infaunal density, inducing its higher heterogeneity in comparison to bare sediment found in the deep-sea.…”

“…Multibeam bathymetry of the area indicated an overall flat slope, and ROV video surveys did not indicate the presence of rocky environments near the study area. BB samples were collected at depths of 874-1007 m. The sites were characterized by areas of bare sediment and biogenic habitats comprised of sponge gardens Iophon koltuni (Dinn et al, 2019) and bamboo corals Keratoisis sp. (Neves et al, 2015) in FB and BB, respectively.…”

“…living on a soft substrate in the Southeast of Baffin Bay (873 m). Furthermore, Dinn et al (2019) reported the presence of dense aggregations of sponges (Iophon koltuni) on soft substrate in Frobisher Bay (137 m).…”

Geographic range extensions of stalked, flabelliform sponges (Porifera) from eastern Canada with a new combination of a species of Plicatellopsis in the North Atlantic

“…In Canadian waters, sponge grounds formed by large, dense, often boulder-shaped sponges are common in the North Atlantic (Hogg et al 2010;Klitgaard & Tendal 2004), and elaborate glass sponge reefs occur near British Columbia (Conway et al 1991;Krautter et al 2001;Maldonado et al 2017) which form habitat for diverse communities of invertebrates and fish (Chu & Leys 2010;Dunham et al 2018). Less elaborate sponge aggregations described as sponge gardens have also been identified in Canada, including dense patches of bush-like Iophon sponges in Frobisher Bay (Dinn et al 2019). Conversely, flabelliform sponges (including leaf-like and vase shaped forms) are often solitary, though some species may aggregate in particular habitats (Ginn et al 2000) .…”