Identification of significant concentrations of sea pens in the Gulf of St. Lawrence biogeographic unit using Kernel density estimation (KDE). This method was applied to create a modelled biomass surface for each taxa and an aerial expansion method was permitted to identify significant concentrations. Only geo-referenced biomass data have been used to identify the “hot spots”. The borders of the areas were refined using knowledge of null catches and species distribution models. Predictive models were produced using a random forest machine-learning technique. For more details, please refer to this report: Kenchington, E., L. Beazley, C. Lirette, F.J. Murillo, J. Guijarro, V. Wareham, K. Gilkinson, M. Koen Alonso, H. Benoît, H. Bourdages, B. Sainte-Marie, M. Treble, and T. Siferd. 2016. Delineation of Coral and Sponge Significant Benthic Areas in Eastern Canada Using Kernel Density Analyses and Species Distribution Models. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/093. vi + 178 p. http://waves-vagues.dfo-mpo.gc.ca/Library/40577806.pdf The present layer only contains the analysis results for sea pens. Purpose: As part of the Canada's commitment to the identification and protection of sensitive benthic marine ecosystems, maps of the location of significant concentrations of corals and sponges on the east coast of Canada were produced through quantitative analyses of research vessel trawl survey data, supplemented with other data sources where available. The taxa analyzed are sponges (Porifera), large and small gorgonian corals (Alcyonacea), and sea pens (Pennatulacea). However, only the sponges (Porifera) and sea pens (Pennatulacea) have been considered in the analysis concerning the Gulf of St. Lawrence biogeographic unit.

Polygons denoting concentrations of sea pens, small and large gorgonian corals and sponges on the east coast of Canada have been identified through spatial analysis of research vessel survey by-catch data following an approach used by the Northwest Atlantic Fisheries Organization (NAFO) in the Regulatory Area (NRA) on Flemish Cap and southeast Grand Banks. Kernel density analysis was used to identify high concentrations and the area occupied by successive catch weight thresholds was used to identify aggregations. These analyses were performed for each of the five biogeographic zones of eastern Canada. The largest sea pen fields were found in the Laurentian Channel as it cuts through the Gulf of St. Lawrence, while large gorgonian coral forests were found in the Eastern Arctic and on the northern Labrador continental slope. Large ball-shaped Geodia spp. sponges were located along the continental slopes north of the Grand Banks, while on the Scotian Shelf a unique population of the large barrel-shaped sponge Vazella pourtalesi was identified. The latitude and longitude marking the positions of all tows which form these and other dense aggregations are provided along with the positions of all tows which captured black coral, a non-aggregating taxon which is long-lived and vulnerable to fishing pressures. These polygons identify sponge grounds from the broader distribution of sponges in the region as sampled by Campelen trawl gear in the Newfoundland - Labrador Shelves biogeographic zone. A 200 kg minimum threshold for the sponge catch was identified as the weight that separated the sponge ground habitat from the broader distribution of sponges with these research vessel tow data and gear type.

Sponge species distribution and biomass was investigated in Caribbean and western Atlantic reefs in 7 countries (Belize, Jamaica, USA (Florida), Bahamas, Puerto Rico, US Virgin Islands and Barbados).The reefs of Belize were intensively surveyed. Surveys were conducted at 5, 10, 15 and 20 m on the seaward facing slopes of Wee Wee Cay, South Water Cay and Glovers Reef. Triplicate 20 m x 2 m transects were surveyed along the depth profile at each depth. All sponges, except boring, thin encrusting and cryptic species were collected, identified to species where possible and weighed. Surveys at Wee Wee Cay at 10 and 15 m were limited to 8 m² because of the large number and volume of sponges. Any additional species that occurred in the remaining 32 m² were recorded. Very large specimens of Xestospongia muta were not collected, but the weights were estimated by calculating the volume from linear measurements and using a weight/volume correction factor calculated from smaller specimens or parts of larger animals which were weighed. Such estimates were made conservatively, erring on the side of underestimation.Similar surveys were carried out in Jamaica (Discovery Bay), USA (Key Largo - French Reef), Bahamas (Exuma Cays - Lee Stocking Island), Puerto Rico (Cayo Enrique, Media Luna), US Virgin Islands (Saint Croix - Buck Island, Tague Bay, Salt River Canyon) and Barbados (West). Triplicate transects were surveyed at depths of 10 m and 20 m at most locations. Transects were variable in size, ranging from 3 m x 2 m to 30 m x 2 m. This research was undertaken to survey sponge species distribution and biomass on Carribean Reefs for comparison with similar data from the central Great Barrier Reef. During these surveys, benthic cover was also surveyed at most locations, using the Line Intercept Transect method.

Sponge population surveys were conducted in mid-winter (July 1983) at 8 sites along a 1.3 km transect across the reef flat, north of the weather station on Flinders Cay. All sponges within duplicate 2 x 2 m quadrats were collected, identified and weighed (wet weight). Respirometry was used to measure rates of oxygen exchange on 20 to 55 g (wet weight) samples of sponge tissue. Rates were measured for 5 specimens of each of Carteriospongia "folpap", Carteriospongia "cups" and Phyllospongia "fingers" and 2 specimens of Thorectidae "firmred". Integrated daily productivity was estimated by using light profiles, measured at the time and interpreted using published equations. Summer productivity rates were estimated using the July production and respiration rates and summer light profiles, with no provision for changes in photoadaptation or temperature. Chlorophyll a content (µg/g wet weight) and mean thickness (mm) of the sponge tissue used for respirometry were also measured. This research was undertaken to determine the contribution of sponges to reef flat productivity by:1. estimating the size and extent of sponge populations on the reef flat2. measuring photosynthetic production and respiration of specimens of the most abundant sponge species present Specimens of sponges were provided to Professor PR Bergquist of the Australian Museum with the following registration numbers:Thorectidae "firmred": Z4970Carteriospongia "folpap": Z4977Phyllospongia "fingers": Z4978Carteriospongia "cups": Z4974

Between 2002 and 2014 Torres Strait was surveyed to assess seagrass presence and absence, and biomass (grams dry weight per m2) in the intertidal and subtidal zone.

Kernel density estimation (KDE) utilizes spatially explicit data to model the distribution of a variable of interest. It is a simple non-parametric neighbour-based smoothing function that relies on few assumptions about the structure of the observed data. It has been used in ecology to identify hotspots, that is, areas of relatively high biomass/abundance, and in 2010 was used by Fisheries and Oceans Canada to delineate significant concentrations of corals and sponges. The same approach has been used successfully in the Northwest Atlantic Fisheries Organization (NAFO) Regulatory Area. Here, we update the previous analyses with the catch records from up to 5 additional years of trawl survey data from Eastern Canada, including the Gulf of Saint Lawrence. We applied kernel density estimation to create a modelled biomass surface for each of sponges, small and large gorgonian corals, and sea pens, and applied an aerial expansion method to identify significant concentrations of these taxa. We compared our results to those obtained previously and provided maps of significant concentrations as well as point data co-ordinates for catches above the threshold values used to construct the significant area polygons. The borders of the polygons can be refined using knowledge of null catches and species distribution models of species presence/absence and/or biomass.

Funded under DFO's Marine Conservation Targets Program in partnership with the Huntsman Marine Science Centre (HMSC), this diver-based imagery and sample collection benthic survey documents the occurrence of sponges at 42 dive sites in the Eastern Shore Islands (ESI) Area of Interest (AOI, ~2089 km2) off the Atlantic coast of Nova Scotia, Canada from dive surveys conducted in summer 2021 and 2022. Water quality, species occurrences and counts, habitat, slope, and substrate characteristics were catalogued through diver log sheets, camera imagery, specimen vouchers, and high-resolution bathymetric data. A total of 54 dives to depths from 11 to 33 m (below sea level), collecting up to 147 still images, one-hour of video, and 17 specimen samples per site, resulted in 220 observations for 27 different sponge taxa. This included three new records for Canada (Hymedesmia stellifera, Plocamionida arndti, Hymedesmia jecusculum) and a range extension for a species new to science (Crellomima mehqisinpekonuta) which was recently described from the Bay of Fundy. There were also four species which may seem to be new to science (Halichondria sp., Hymedesmia sp., Protosuberires sp., and Sphaerotylus sp.). Sponges were found to occupy a diversity of micro-habitats, often several different ones in proximity. A total of eight distinct habitat classes were defined, based on varying abundances and diversity of sponges and associated benthic species. These are likely widely distributed among the many complex submerged seabed features within this AOI. Collected specimens were preserved and are stored at the Atlantic Reference Centre (ARC) in St. Andrew's, New Brunswick. Cite this data as: Goodwin, C., Cooper, J.A., Lawton, P., Teed, L.L. 2025. Sponge occurrence and associated species and habitat descriptions derived from the 2021 and 2022 SCUBA diving surveys in the Eastern Shore Islands Area of Interest, Nova Scotia. Version 1.4. Fisheries and Oceans Canada. Occurrence dataset. https://ipt.iobis.org/obiscanada/resource?r=eastern_shore_islands_sponge_survey_2021_2022&v=1.4

Effective fisheries and habitat management processes require knowledge of the distribution of areas of high ecological or biological significance. On the Scotian Shelf and Slope, a number of benthic ecologically or biologically significant areas consisting of habitat-forming species such as sponges and deep-water corals have been identified. However, knowledge of their spatial distribution is largely based on targeted surveys that are limited in their spatial extent. We used a species distribution modelling approach called random forest (RF) to predict the probability of occurrence and biomass of sponges, sea pens, and large and small gorgonian corals across the entire spatial extent of Fisheries and Oceans Canada’s (DFO) Maritimes Region. We also modelled the rare sponge Vazella pourtalesi, which forms the largest known aggregation of its kind on the Scotian Shelf. We utilized a number of data sources including DFO multispecies trawl catch data and in situ benthic imagery observations. Most models had excellent predictive capacity with cross-validated Area Under the Receiver Operating Characteristic Curve (AUC) values ranging from 0.760 to 0.977. Areas of suitable habitat were identified for each taxon and were contrasted against their known distribution and when applicable, the location of closure areas designated for their protection. Generalized additive models (GAMs) were developed to predict the biomass distribution of each taxonomic group and serve as a comparison to the RF models. The RF and GAM models provided comparable results, although GAMs provided superior predictions of biomass along the continental slope for some taxonomic groups. In the absence of data observations, the results of this study could be used to identify the potential distribution of sensitive benthic taxa for use in fisheries and habitat management applications. These results could also be used to refine significant concentrations of these taxa as identified through the kernel density analyses. Cite this data as: Beazley, Lindsay; Kenchington, Ellen; Murillo-Perez, Javier; Lirette, Camille; Guijarro-Sabaniel, Javier; McMillan, Andrew; Knudby, Anders (2019). Species Distribution Modelling of Corals and Sponges in the Maritimes Region for Use in the Identification of Significant Benthic Areas. Published July 2023. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/356e92f3-5bf3-4810-98b1-3e10cd7742aa