Habitat-Forming Bryozoans in New Zealand: Their Known and Predicted Distribution in Relation to Broad-Scale Environmental Variables and Fishing Effort

Abstract

Frame-building bryozoans occasionally occur in sufficient densities in New Zealand waters to generate habitat for other macrofauna. The environmental conditions necessary for bryozoans to generate such habitat, and the distributions of these species, are poorly known. Bryozoan-generated habitats are vulnerable to bottom fishing, so knowledge of species’ distributions is essential for management purposes. To better understand these distributions, presence records were collated and mapped, and habitat suitability models were generated (Maxent, 1 km2 grid) for the 11 most common habitat-forming bryozoan species: Arachnopusia unicornis , Cellaria immersa , Cellaria tenuirostris , Celleporariaagglutinans , Celleporinagrandis , Cinctipora elegans , Diaperoecia purpurascens , Galeopsis porcellanicus , Hippomenella vellicata , Hornerafoliacea , and Smittoideamaunganuiensis . The models confirmed known areas of habitat, and indicated other areas as potentially suitable. Water depth, vertical water mixing, tidal currents, and water temperature were useful for describing the distribution of the bryozoan species at broad scales. Areas predicted as suitable for multiple species were identified, and these ‘hotspots’ were compared to fishing effort data. This showed a potential conflict between fishing and the conservation of bryozoan-generated habitat. Fishing impacts are known from some sites, but damage to large areas of habitat-forming bryozoans is likely to have occurred throughout the study area. In the present study, spatial error associated with the use of historic records and the coarse native resolution of the environmental variables limited both the resolution at which the models could be interpreted and our understanding of the ecological requirements of the study species. However, these models show species distribution modelling has potential to further our understanding of habitat-forming bryozoan ecology and distribution. Importantly, comparisons between hotspots of suitable habitat and the distribution of bottom fishing in the study area highlight the need for management measures designed to mitigate the impact of seafloor disturbance on bryozoan-generated habitat in New Zealand waters.

Enhancing georeferenced biodiversity inventories: automated information extraction from literature records reveal the gaps

“…Independent taxonomic surveys of underrepresented regions in one or both datasets corroborate the existence of significant gaps ( López Gappa, 2000 ; Barnes & Griffiths, 2008 ; Liu, 2008 ; Vieira, Migotto & Winston, 2008 ; Hirose, 2017 ; Boonzaaier-Davids, Florence & Gibbons, 2020 ; Denisenko, 2020 ; Sanjay et al, 2020 ). The DB records may partly reflect recent histories of active bryozoan research programs in the Antarctic ( Barnes & Griffiths, 2008 ) and Australia and New Zealand ( Wood et al, 2013 ) as well as contributions to OBIS and GBIF that differ substantially among research institutions. On the other hand, TMO extracted extensive species-location information from the Mediterranean (27° to 50°) that are severely wanting in OBIS, demonstrating that combining disparate data sources can help bridge gaps in global biogeographic studies.…”

“…They are the most diverse order of Bryozoa with a conservatively estimated 4,921 extant described species ( Bock & Gordon, 2013 ), or 83% of all Bryozoa. Bryozoans are ecologically important habitat builders ( Wood et al, 2013 ) and are vital components of the marine food chain ( Lidgard, 2008 ). Despite important analyses of regional species distributions ( Clarke & Lidgard, 2000 ; López Gappa, 2000 ; Barnes & Griffiths, 2008 ; Hirose, 2017 , Boonzaaier-Davids, Florence & Gibbons, 2020 ; Denisenko, 2020 ), their global species richness distribution has never been quantified.…”

Compositional Differences in the Habitat-Forming Bryozoan Communities of the Antarctic Shelf

“…Although several studies include bryozoans as being one of the more common and diverse members of the shelf fauna (e.g., Barnes and Kuklinski, 2010;Barnes et al, 2016;Figuerola et al, 2018), the impact of expansive bryozoan secondary structures on the surrounding community has not been evaluated on a wide geographic scale (Wood et al, 2013). Evaluating the geographic distribution of habitat-forming bryozoan communities in other Antarctic regions based on published studies using direct sampling or remote-imaging techniques (or both) can be difficult due to interpretational differences in categorizing bryozoan-rich habitats.…”

Editorial: One size does not fit all: Do taxonomic biases in marine connectivity studies reduce effectiveness of marine conservation?

“…Biogenic habitat‐forming taxa include many phyla with a range of life history strategies, from broadcast spawning corals often having long PLDs, to marine plants (mangroves, seagrasses) and algae that are the dominant structural component in many coastal hard substrate ecosystems, and whose PLDs are often limited to a few hours in the plankton. Most biogenic habitat formers on soft sediments are predicted to have short PLDs; examples include the majority of bryozoan species with PLDs of <1 day (Gordon, ; Wood, Rowden, Compton, Gordon, & Probert, ), and larval durations of a few hours or less have been observed for a colonial ascidian (Young, ). Reviews of available information on New Zealand marine vertebrate and invertebrate life history strategies suggest these taxonomic differences in dispersal potential are globally applicable (Lundquist et al, unpublished manuscript).…”