Persistence and Variation on the Groundfish Assemblages on the Southern Grand Banks (NAFO Divisions 3NO): 2002–2011

• Published in: Journal of Northwest Atlantic Fishery Science
• Main Authors: Nogueira, Adriana, Paz, Xabier, González-Troncoso, Diana
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: fish diversity; Centro Oceanográfico de Vigo; Pesquerías; trawl survey; accumulation curve; depth zonation; size-depth relationship; Diversidad peces; campaña de arrastre; curvas acumuladas; zonación batimétrica; relación talla-profundidad; Arctic; Greenland; Hake; atlantic cod; Bathyraja spinicauda; Gadus morhua; Newfoundland; North Atlantic; Northwest Atlantic
• Online Access: http://hdl.handle.net/10508/1567; http://hdl.handle.net/10261/328927; https://doi.org/10.2960/J.v45.m686

Data from EU-Spain (Instituto Español de Oceanografía) bottom trawl surveys in the NAFO Regulatory Area (2002–2011) were analyzed to examine patterns on the South of Grand Banks (NAFO Div. 3NO) of groundfish assemblage structure and diversity in relation to depth. The 1160 hauls from the slope surveys spanned between 38 and 1460 m in depth. We focused on the 28 most abundant species, which made up 92.6% of the catch in terms of biomass. Assemblage structure was strongly correlated with depth. For the most part, changes in assemblages seem to be fairly continuous, although there were more abrupt changes at 300 m. Five assemblages were identified. Two shallow assemblages were found in the shelf. Assemblage I (Shallow) comprises the strata with depths lesser than 150 and include yellowtail flounder (Limanda ferruginea), American plaice (Hippoglossoides platessoides), Northern sand lance (Ammodytes dubius), moustache sculpin (Triglops murrayi), capelin (Mallotus villosus) and web sculpin (Hemitripterus americanus). Assemblage II (Shallow) includes the strata with depths between 151 and 300 m and comprises Atlantic cod (Gadus morhua), American angler (Lophius americanus), wolfish (Anarichas lupus) and thorny skate (Amblyraja radiata). Assemblage III (Intermediate) contains the depth strata between 301 and 600 m. Redfish (Sebastes spp.), spotted wolfish (Anarhichas minor), Arctic eelpout (Lycodes reticulatus), Northern wolfish (Anarhichas denticulatus), white hake (Urophycis tenuis), witch flounder (Glyptocephalus cynoglossus) and longfin hake (Phycis chesteri) were included in the intermediate assemblage. Finally, we found two deep clusters: Assemblage IV (Deep) contains the depths between 601 and 1000 m, and Assemblage V (Deep) the depth strata greater than 1001 m. Greenland halibut (Reinhardtius hippoglossoides), marlin-spike (Nezumia bairdii), roughhead grenadier (Macrourus berglax) and spinytail skate (Bathyraja spinicauda) formed Assemblage IV. Snubnosed spiny eel (Notacanthus chemnitzii), blue antimora ...