Juvenile Spotted Skate (Raja montagui) can be confused with the morphologically similar Blonde Skate (Raja brachyura) and Thornback Skate (R. clavata). Adults can be misidentified with Blonde Skate and, in the Mediterranean Sea, with Speckled Skate (Raja polystigma). Some specimens of Spotted Skate have a few spots that are concentrated in the centres of the wings, and the presence of such false eyespots can lead to potential confusion with Cuckoo Skate (Leucoraja naevus).

The Spotted Skate (Raja montagui) is a small to medium-sized (to 80 cm total length) skate found in the Northeast and Eastern Central Atlantic Ocean, from Norway to Morocco, and parts of northern Africa in the Mediterranean Sea. It is most frequent on the continental shelf (to depths of 10–200 m) but also occurs on the upper slope and may be found at depths down to 650 m, and possibly to 800 m. The Spotted Skate is an important commercial species across its range, and is caught in mixed demersal fisheries using trawl, set net (gillnet and trammel), and longline. The species is increasing in abundance the Northeast Atlantic. The Spotted Skate is rare in the Mediterranean Sea, where populations have been stable until 2021 when its abundance increased. However, misidentification of the Spotted Skate with similar looking species (e.g., Speckled Skate, Raja polystigma) makes it difficult to determine long-term abundance trends of this species in the Mediterranean Sea. There are few data available from Morocco in the Eastern Central Atlantic, although sharks and rays have been exploited by semi-industrial fisheries since the 1950s in the region. This area of Morocco accounts for a relatively minor part of its range. Across most of its range, the population is increasing. There is no evidence of population decline and the species is not suspected to be close to reaching the population reduction threshold, and the Spotted Skate is assessed as Least Concern.

The Spotted Skate is found in the Northeast Atlantic and northern part of the Eastern Central Atlantic Ocean, from Norway to Morocco, and northern Africa in the Mediterranean Sea (Last et al. 2016, Ebert and Dando 2021). The distribution in the rest of the Mediterranean Sea is uncertain, partly due to misidentifications with Speckled Skate (Raja polystigma) (Cannas et al. 2008, Frodella et al. 2016).

There are no data available on the absolute global population size of the Spotted Skate. Population trend data are available from two sources: (1) the Northeast Atlantic (Marandel et al. 2019, ICES unpub. data); and (2) Mediterranean Sea (MEDITS unpub. data). The trend data from each source were analysed over three generation lengths using a Bayesian state-space framework (a modification of Sherley et al. 2020, Winker et al. 2020). This analysis yields an annual rate of change, a median change over three generation lengths, and the probability of the most likely IUCN Red List category percent change over three generations (see the Supplementary Information).

Within the Northeast Atlantic, the species is one of the more frequently observed skates on the continental shelf. ICES provide advice for stocks of Spotted Skate in the following areas: (1) North Sea and eastern Channel, (2) Irish Sea, Bristol Channel, western Channel and Celtic Sea (3) North-west Scotland and west of Ireland, (4) Bay of Biscay and Cantabrian Sea, and (5) Iberian waters of Division 9. Stock size indicators are used in the assessment for these stocks (ICES 2022). It should be noted that these stock areas use data for only the ‘exploitable biomass’ (larger than 50 cm total length, TL), and thus include a proportion of fish that are immature individuals and not wholly representative of the adult population. The trend analysis of the North Atlantic modelled biomass for 1950–2021 (71 years) revealed annual rates of increase of 4.22% over three generation lengths (27 years), with the highest probability of no major reductions in population over the past three generation lengths.

In the Mediterranean Sea, data are collected during the MEDiterranean International Trawl Survey (MEDITS) and these data indicate that the Spotted Skate may be encountered routinely (1,472 captures between 1994–2021) and stable at a low level until 2019–2021 when the swept area biomass index increased significantly. However, misidentification with the (more abundant) Speckled Skate (R. polystigma) is common. The trend analysis of the Mediterranean Sea modelled biomass for 1994–2021 (27 years) revealed annual rates of increase of 11.5% over three generation lengths (27 years), with the highest probability of no major reductions in population over the past three generation lengths. However, the misidentifications make it difficult to determine if this is fully representative of long-term abundance trends of this species in the Mediterranean Sea.

In the Eastern Central Atlantic, both overall catch and effort have continued to rise in the major shark and ray fishing countries. Across West Africa, total artisanal fishing effort increased 10-fold between 1950–2010, while the catch-per-unit-effort (CPUE) of artisanal and industrial vessels declined by 34% over this period (Belhabib et al. 2018). Many regional fisheries are now characterised by severe overexploitation and declines in abundance of marine resources (e.g., Gascuel et al. 2007). While these levels of declines are not species-specific, they are informative for understanding the broader levels of decline in sharks and rays in the region. However, this region accounts for a relatively small proportion of the Spotted Skate geographic range, and the population is increasing across most of its range. There is no evidence of population decline and the species is not suspected to be close to reaching the population reduction threshold.

The Spotted Skate is demersal on the continental shelf and upper slope at depths of 10–650 m, and possibly to 800 m (Ebert and Dando 2021), but is most common in waters 10–200 m (Ellis and Walls 2015). It reaches a maximum length of at least 72 cm total length (TL), and possibly to 80 cm TL (Ellis et al. 2005). Males mature at 40–50 cm TL and females mature at 49–64 cm TL (McCully et al. 2012, Ebert and Dando 2021). Reproduction is oviparous. Females produce 60–70 egg cases annually and size at hatching is ~10–13 cm TL (Last et al. 2016). Female age-at-maturity is 5.6 years (Villagra et al. 2022) and maximum age is 12 years (Walker 1999), resulting in a generation length of 9 years.

The Spotted Skate is a relatively important commercial skate species. While this species is not targeted specifically (due to its smaller size), it may be taken in fisheries targeting other skate species, fisheries targeting the overall skate complex, and in mixed demersal fisheries. The main gears in which Spotted Skate is caught include demersal trawl, set net (gillnet and trammel) and, to a lesser extent, longline (ICES 2023). In the Northeast Atlantic, skates have been landed since the 1800s, and became increasingly marketable by the late 1800s/early 1900s (Ellis et al. 2010). Fisheries were largely unregulated, and fishing quotas for skates in the North Sea were only introduced in 1999, and further applied to all vessels operating in European Union Atlantic waters in 2009 (EC 1999, 2009). Earlier management efforts treated skates as one skate complex, and species-specific measures were only first introduced in 2007 (Ellis et al. 2010). Long-term extensive and intensive fishing pressure has led to documented population reductions, localized extinctions, and widespread changes to the shark and ray community structure across the range of the Spotted Skate in the Northeast Atlantic (Dulvy and Reynolds 2002, Marandel et al. 2019). The effects of fishing have been greatest on large-bodied skates species rather than smaller bodied species such as the Spotted Skate (Dulvy et al. 2000, Ellis et al. 2010).

In the Mediterranean Sea, the Spotted Skate has been subject to extensive and intensive fishing across much of the species' known depth and spatial distribution. Skates are caught with demersal trawl, trammel net, and longline gear (e.g., Carbonara et al. 2020, Ferragut-Perello et al. 2023). The Spotted Skate is reported infrequently (Geraci et al. 2021). Skates (Raja spp.) are the most fished elasmobranchs in parts of the Mediterranean Sea and neighbouring areas. For example, in the Gulf of Cádiz, skates represented up to 50% of regional elasmobranch landings (Biton-Porsmoguer and Lloret 2020). Misidentification of the Spotted Skate with similar looking species (e.g., Speckled Skate Raja polystigma) makes it difficult to determine long-term abundance trends (ICES 2023).

There is little information available for the Spotted Skate across the remainder of its range. However, in the Eastern Central Atlantic, sharks and rays have been exploited by semi-industrial fisheries since in the 1950s (Walker et al. 2005). Over the years, this has expanded into targeted shark and ray fisheries across many countries and is likely increasing fishing pressure on this species (Walker et al. 2005, Diop and Dossa 2011). In general, fishing effort and the number of fishers has intensified in recent decades across the range of this species. Reports indicate that the diversity and average body size of many important commercial coastal, demersal, and pelagic fishery species have markedly declined with many stocks now considered to be overexploited (CCLME 2016, Polidoro et al. 2017). The direct cause of decline for many of these stocks has been attributed to overcapacity within both the industrial and artisanal fisheries and destructive fishing practices (GCLME 2006, CCLME 2016).

Climate change may influence the distributions of various European fish populations, including skates, in a manner that may influence the assessment of population trends and the potential viability of subpopulations (Simpson et al. 2011, Sguotti et al. 2016). Analyses of the Northeast Atlantic International Council for the Exploration of the Sea (ICES) research trawls over 24 years (1997–2020) revealed that the habitat suitability has been altered by ongoing climate change for Spotted Skate and has expanded eastwards, increasing moderately in the Irish Sea, St George's Channel, Scottish Sea, and around the Orkney Islands (Coulon et al. 2024).

The Spotted Skate is utilized for its meat and is commercially valued for its wings. Products of the Spotted Skate may be marketed under a generic "ray" or "skate" label or mislabelled as a different species (Griffiths et al. 2013). The smaller body size of this species in the mixed skate target assemblage means it has a lower market value and thus, where quotas are limited, it may be discarded. Unmarketable parts of the ray may be used to supply bait for pot fisheries (Bullimore et al. 2001).

The species is likely to be used across the remainder of its range where retention is allowed or unregulated. Skate meat is consumed across West Africa, where it may also be dried or dried and smoked, and exported across West Africa to supply countries such as Ghana, Guinea, Nigeria, Mali, and Burkina Faso (e.g., Jabado et al. 2021).

Within the EU and UK waters of the ICES area, exploitation on Spotted Skate is regulated largely through catch quotas for skates and rays (Rajiformes) (ICES 2023). There are some local and national management measures in place across the species range. For example, there is a minimum conservation reference size (or minimum landing size) of either 40 cm or 45 cm (disc width) for skates and rays caught in the inshore waters of parts of the coasts of England and Wales. In Portugal, there is a limit on landing skates (Rajidae) in the nominal May-June spawning period, whereby skates and rays should not be landed (except where skate and ray landings are less than 5% of the landings). Portugal also has a minimum landing size (52 cm total length) for all Raja spp.

Further information is required on the life history and ecology, as well as more detailed information on its distribution, interactions with fisheries and population trends in the relevant parts of the Mediterranean Sea and off Northwest Africa.