Figure 1.
The deep-sea Gulf of Maine census area.
A) The deep-sea Gulf of Maine census area, showing eastern and western boundaries of Gulf of Maine Area Program in white. Note use of two depth scales in the color bar. B) Canyons, continental slope and shelf edge of Georges Bank NW of Bear Seamount. Depth scale is shown on the right-hand side. C) NE Channel and slope. Depth scale is same as in B. D) Bear Seamount (summit depth ∼1100 m). Other seamounts shown are Physalia (to the east) and Mytilus (southeast). Depths in panels A, B and C are from the USGS Digital Bathymetry for the Gulf of Maine (∼500m/pixel). Panel A was augmented with data from the General Bathymetric Chart of the Oceans [GEBCO (∼1000m/pixel)]. Depths in panel D are from high resolution (100m/pixel) bathymetric data processed by the Center for Coastal and Ocean Mapping/Joint Hydrographic Center, University of New Hampshire.
Table 1.
Definitions of sub-regions used in this study.
Table 2.
Description of studies used to create species accumulation curves for 5 different sub-regions.
Table 3.
Total number of species and number of records of species' occurrence recorded for each sub-region within the deep-sea database.
Table 4.
Ten most frequently reported species within the deep-sea database.
Figure 2.
The number of database records in relation to known species.
Positive correlation (Pearson's r = 0.86, p<0.025) between the number of records compiled within the deep-sea database (representing the number of times a sub-region has been sampled, used as a proxy for sampling effort) and the number of known species within each sub-region.
Figure 3.
Cumulative number of known species in the deep-sea database within six sub-regions since 1950.
Figure 4.
Cumulative number of species records in the deep-sea database within six sub-regions since 1950.
Table 5.
The number of known species by Kingdoms and Phyla within each of 6 sub-regions.
Table 6.
The number of known species by Order within the Phylum Chordata, Class Actinopterygii, within each of 6 sub-regions.
Table 7.
The number of known species by Order within the Phylum Chordata, Class Elasmobranchii, within each of 6 sub-regions.
Table 8.
The number of known species by Class for Phylum Mollusca within each of 6 sub-regions.
Table 9.
The number of known species by Order for Phylum Arthropoda, Class Malacostraca, within each of 6 sub-regions.
Table 10.
The number of known species by Class for Phylum Echinodermata within each of 6 sub-regions.
Table 11.
The number of known species by Order for Phylum Cnidaria, Class Anthozoa, within each of 6 sub-regions.
Figure 5.
Spatial distribution of the number of known species across the deep-sea Gulf of Maine region.
Grid squares are 0.2 degrees and include species records throughout the water column (from 150 m to the seafloor). Species counts are not corrected for effort or sampling method. Dots represent a species record. The names and locations of the major canyons and Bear Seamount are identified by arrows.
Figure 6.
Average taxonomic distinctness (Δ+) by number of species for each sub-region.
Central line is average taxonomic distinctness for the total list. Funnel lines are confidence limits within which 95% of simulated values lie.
Figure 7.
Variation in taxonomic distinctness (Λ+) by the number of species for each sub-region.
Central line is variation in taxonomic distinctness for the total list. Funnel lines are confidence limits within which 95% of simulated values lie.
Figure 8.
Taxonomic distinctness values by sub-region.
Scatter plot of variation in taxonomic distinctness (Λ+) against average taxonomic distinctness (Δ+) values for species lists from 6 sub-regions, showing a strong negative correlation (Pearson's r = −0.87, p<0.05). Dotted lines denote Δ+ and Λ+ values of the master species list from Figs 6 & 7.
Table 12.
Bray-Curtis similarity values (%) (based on presence/absence data) for the species lists among 6 different sub-regions.
Figure 9.
Bray-Curtis similarity (%) of the total deep-sea region species list and the species lists for 6 different sub-regions to the continental shelf Gulf of Maine species list.
Figure 10.
Estimated species richness (Sobs) curves by number of samples.
(A) Canyon sub-region for epibenthic macro- and megafauna, as imaged in submersible photographs in Lydonia, Oceanographer and Veatch canyons in 1984 (data from [29]); Continental Rise sub-region for (B) demersal megafauna, collected from trawls using a 41′ Gulf of Mexico net between 2150–2650 m (data from [43], [44]), and (C) epibenthic and demersal macro- and megafauna, as imaged in submersible photographs between 2500–2600 m (data from Metaxas, unpublished); (D) Continental Slope sub-region for infaunal macrofauna sampled with box cores in 1983–84 at different depth stations (data from [26]); (E) NE Channel sub-region for epibenthic and demersal macro- and megafauna, as imaged in submersible photographs across different depths (data from Metaxas, unpublished); and (F) Seamount sub-region (Bear Seamount) for meso- and bathypelagic megafauna sampled using IGYPT nets, collected July 2002 (data from [30]).
Figure 11.
Asymptotic species richness estimates.
Comparison of the asymptotic species richness estimates (Chao 1 and Chao 2) for 5 different sub-regions in the deep-sea region of the Gulf of Maine. The Chao 1 estimate for Bear Seamount could not be calculated due to lack of singletons within the data.
Table 13.
Estimates of the unknown biodiversity in the deep-sea system of the Gulf of Maine.