Deep-sea sponge grounds of the Flemish Cap, Flemish Pass and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): Distribution and species composition

Abstract

Distribution and species composition of deep-sea sponge grounds of the Flemish Cap, Flemish Pass and the Grand Banks of Newfoundland are described based on Spanish/EU bottom trawl groundfish surveys between 40 and 1500 m depth. Four areas with large catches of sponges and at least 30 different species have been identified in the study area. Geodia barretti, Geodia macandrewii, Geodia phlegraei, Stryphnus ponderosus and Stelletta normani are the main structural sponges and constitute more than 94% of the total invertebrate biomass of these grounds. The temperature and salinity observed over these bottoms ranged between 3.38 and 3.84°C and between 34.85 and 34.90‰, respectively. The biomass of deep-water sponges per swept area was significantly higher on lightly or untrawled bottoms than in the grounds that are regularly fished. Data from trawl groundfish surveys cannot map the deep-sea sponge grounds to a precision less than the trawl distance of 1.5 nm. Nevertheless it has been used by the Northwest Atlantic Fisheries Organization (NAFO), along with additional Canadian data, to implement the 61/105 United Nations General Assembly Resolution in closing six areas to bottom fishing activities to protect the sponge grounds of the NAFO Regulatory Area.

Keywords:

• Sponge grounds
• fisheries
• NAFO
• Northwest Atlantic Ocean
• Vulnerable Marine Ecosystems

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

This work was made possible with the support of the Instituto Español de Oceanografía (IEO) under the ECOVUL/ARPA interdisciplinary project and the Spanish Government (Secretaría General del Mar), and is part of F.J.M.'s PhD research funded by the IEO. We are especially grateful to the scientific staff involved in NAFO surveys, and the heads of these surveys for facilitating the data collection and to the research vessels crews (RV Vizconde de Eza) for assistance at the sea. We are also indebted to Alfonso Pérez Rodríguez for his collaboration in the invertebrate sampling during the 2007 EU Flemish Cap survey and Fernando González Costas for valuable comments to the text. The manuscript was improved thanks to the comments of two anonymous reviewers. NAFO groundfish surveys and NAFO Observers are co-funded by the EU and the Spanish Government.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark