Summary Weight–length (W–L) relationships were estimated for 46 species of fish captured off the western Portuguese coast between April 1994 and September 1995. The best‐represented family was Scyliorhinidae (2677 fishes), followed by Gadidae (1871), Sparidae (1682) and Merlucciidae (1108). The estimates for the parameter b of the W–L relationship (W = aLb) ranged between 2.171 and 3.873, with a median of 3.124. Significant variations in b were found at seasonal level for striped red mullet (Mullus surmuletus), axillary seabream (Pagellus acarne), greater weever (Trachinus draco) and the sardine (Sardina pilchardus), at the regional level for Atlantic mackerel (Scomber scombrus), and between sexes for the small‐spotted dogfish (Scyliorhinus canicula).

If marine management policies and actions are to achieve long-term sustainable use and management of the marine environment and its resources, they need to be informed by data giving the spatial distribution of seafloor habitats over large areas. Broad-scale seafloor habitat mapping is an approach which has the benefit of producing maps covering large extents at a reasonable cost. This approach was first investigated by Roff et al. (2003), who, acknowledging that benthic communities are strongly influenced by the physical characteristics of the seafloor, proposed overlaying mapped physical variables using a Geographic Information System (GIS) to produce an integrated map of the physical characteristics of the seafloor. In Europe the method was adapted to the marine section of EUNIS (European Nature Information System) classification of habitat types under the MESH project, and was applied at an operational level in 2011 under the EUSeaMap project. The present study compiled GIS layers for fundamental physical parameters in the northeast Atlantic, including (i) bathymetry, (ii) substrate type, (iii) light penetration depth and (iv) exposure to near-seafloor currents and wave action. Based on analyses of biological occurrences, significant thresholds were fine-tuned for each of the abiotic layers and later used in multi-criteria raster algebra for the integration of the layers into a seafloor Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. habitat map. The final result was a harmonised broad-scale seafloor habitat map with a 250 m pixel size covering four extensive areas, i.e. Ireland, the Bay of Biscay, the Iberian Peninsula and the Azores. The map provided the first comprehensive perception of habitat spatial distribution for the Iberian Peninsula and the Azores, and fed into the initiative for a pan-European map initiated by the EUSeaMap project for Baltic, North, Celtic and Mediterranean seas. Highlights ► Spatial seafloor physical characteristics data for the NE Atlantic was compiled. ► Datasets were harmonised to common standards prior to input into a GIS environment. ► The inputs were overlaid via spatial analyses to derive a broad-scale habitat map. ► Habitats were described following the marine section of EUNIS habitat classification. ► Biologically-relevant thresholds were established for delineation of EUNIS categories.

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The relationships of total length (L t ) to girth at opercula (G ope ) and maximum girths (G max ) were estimated for 39 and 22 fish species, respectively, captured off the Portuguese coast between Po´voa do Varzim and Santo Andre´(38°05¢54¢¢-41°15¢36¢¢N and 8°46¢54¢¢-9°31¢13¢¢W). The data were collected between April 1994 and September 1995. The best-represented family was Sparidae (five species), followed by Soleidae and Triglidae (four species each). G ope and G max were found to increase linearly with length for all species, all r 2 values being statistically significant (P < 0.01) and higher than 0.81. When G ope and G max were plotted against length for all species combined, three groups were identified, corresponding to general girth-length relationships: G1 ¼ 1.408 + 0.238 · L t , G2 ¼ 2.455 + 0.328 · L t and G3 ¼ )0.72 + 0.60 · L t for opercula girth and G1 ¼ 3.402 + 0.195 · L t , G2 ¼ 2.211 + 0.374 · L t and G3 ¼ -2.514 + 0.717 · L t for maximum girth. These groups correspond to different body shapes of fishes: G1-round, G2-torpedo-form and G3-compressed body.