Cardigan-Caernarfon Bay is an important reproductive area for four shark and one ray species.

Tope at various life stages regularly use this area for reproductive purposes. Neonate/young-of-the-year (YOY) Tope measuring ≤30 cm total length (TL) have been reported to a dedicated database by anglers in 2015 (n = 1), 2018 (n = 1), 2020 (n = 2), 2021 (n = 5), 2022 (n = 3), 2023 (n = 2), 2024 (n = 3), and 2025 (n = 5) (Project SIARC unpubl. data 2025). One additional neonate/YOY Tope was observed during a Baited Remote Underwater Video Station (BRUVS) survey within the area (Project SIARC unpubl. data 2022). Recreational anglers have also confirmed the contemporary (Facebook 2025) and historical (World Sea Fishing 2005) presence of neonate/YOY Tope in this area. The size-at-birth of this species is 26–40 cm total length (TL) (Ebert et al. 2021). Tope at early life stages appear to use this area between July–October. Additionally, one Tope with mating scars and two Tope with light haemorrhaging/abrasions around the cloacal opening (indications of recent breeding activity) were observed in this area during scientific fishing activities for tagging purposes in June 2025 (Project SIARC unpubl. data 2025). Fishing activity within this area is mostly with rod-and-line, and this is a well-known site within the recreational angling community due to the high numbers of large (and likely pregnant) Tope. Further, given that there is little, if any, mobile gear fishing in this area due to the Scallop Order (Legislation.gov.uk 2010) and the Mobile Gear Order, it is likely these records provide an underestimate of sharks in the area. These are reportedly seasonally present between April–October and recreational anglers share photos and videos of their catches online. Recreational Anglers also indicate that pregnant Tope are seasonally abundant in this area, arriving in April (Fishing in Wales 2025), and large numbers of Tope (e.g., n = 61) can be caught in a short amount of time (6 hours) (YouTube 2022). This is one of the only known locations in the United Kingdom of Great Britain and Northern Ireland which is regularly and predictably used by Tope for reproductive purposes, with pregnant individuals present in spring, neonate/YOYs present in the boreal summer, and sub-adults returning to the area in summer (confirmed via tracking data; possibly to feed) (Project SIARC unpubl. data 2025).

Between 2010–2024, annual surveys were undertaken in this area each year between September–October (Q3) as part of the United Kingdom Beam Trawl Survey (BTS; ICES 2025). During this period, 108 neonate/YOY Starry Smoothhounds measuring =<40 cm TL were recorded in the BTS (Ellis et al. 2005; Ellis et al. 2024; ICES 2025). The size-at-birth for this species is ~28–38 cm TL, and it reaches maturity at 72–85 cm TL for males and ~83–96 cm TL for females (Ebert et al. 2021). Neonate/YOY Starry Smoothhounds were recorded in 2010 (n = 14), 2011 (n = 17), 2012 (n = 7), 2013 (n = 6), 2015 (n = 11), 2016 (n = 5), 2017 (n = 12), 2018 (n = 8), 2019 (n = 6), 2021 (n = 5), 2022 (n = 8), and 2023 (n = 9). This is one of the largest known hotspots of early life stages of this species in the region.

A total of 50 Nursehounds were recorded across all years of the BTS in this area and the broader Cardigan Bay (n = 1–8 per year). Of these, 14 neonate/YOY Nursehounds were recorded within this area, measuring =<30 cm TL (ICES 2025). The size-at-birth of this species is 10–16 cm TL (Ebert et al. 2021). Neonate/YOY Nursehounds were reported in 2010 (n = 3), 2014 (n = 4), and 2019 (n = 7) (ICES 2025). This is one of the few locations within the United Kingdom of Great Britain and Northern Ireland where Nursehounds of this life stage have been reported. The trawl gear used during the BTS is considered to have a lower catchability for early life stage Nursehounds and their egg cases. Additionally, opportunistic sightings of Nursehound egg cases are regularly and predictably reported from this area by citizen scientists undertaking recreational snorkelling and diving activities (although no surveys dedicated to this purpose have been undertaken in this area) (Shark Trust unpubl. data 2025). These reports are compiled into a dedicated database, and egg case identification is confirmed through species-specific guides (Shark Trust unpubl. data 2025). Overall, 63 in-situ Nursehound egg cases have been reported from 12 observations in 2015 (n = 1 observation; n = 6 egg cases), 2017 (n = 3; n = 9 egg cases), 2019 (n = 5; n = 42 egg cases), 2022 (n = 2; n = 4 egg cases), and 2023 (n = 1; n = 2 egg cases) (Shark Trust unpubl. data 2025). Records are associated with the rocky substrate and kelp forests around the Llŷn Peninsula in the area (Burrows et al. 2014; Ellis 2015). The species is known to be particularly associated with reefs and coarse ground in this area (D Curnick pers. obs. 2025). This is one of the largest known regular and predictable clusters of observations of in-situ egg cases of this species within the United Kingdom of Great Britain and Northern Ireland. Since 2010, an additional 11,442 Nursehound egg case records have been recorded washed up on the beaches within this area (Shark Trust unpubl. data 2025).

Cardigan-Caernarfon Bay is one of the only locations within the United Kingdom of Great Britain and Northern Ireland with known contemporary observations of Angelsharks at early life stages across multiple years. Historical observations of Angelsharks within the area have been collated from various sources (including fisher records, social media, magazines, interviews, and outreach events) and compiled into a database. There are at least 234 Angelshark reports (n = 1,249 individuals) recorded from this area before 2011 (Barker et al. 2022). Of these, three individuals were confirmed as neonate/YOY measuring <39 cm TL. The size-at-birth of this species is 26–30 cm TL (Ebert et al. 2021). Three individuals were confirmed as neonate/YOY measuring <39 cm TL, but this is a conservative total of reports, given that records were grouped as ‘recently born or juvenile’ under 60 cm TL (Barker et al. 2022). Contemporary data collection has continued within a dedicated database (Angelshark Conservation Network unpubl. data 2025) whereby citizen scientists are encouraged to submit observations online. Further, records are collated manually from fisher interviews, recreational fisher magazines, forums, and other forms of social media. Since 2011, 86 Angelsharks have been recorded from 63 reports. Size data were available for 61 of these Angelsharks. Of these, five individuals were neonate/YOY measuring <39 cm TL. Eight individuals measured 60–100 cm TL, and 48 measured >100 cm TL (Angel Shark Project: Wales/Project SIARC unpubl. data 2025). In addition, one pregnant Angelshark (with at least three pups) was observed in this area (Angel Shark Project: Wales/Project SIARC unpubl. data 2025). One neonate/YOY Angelshark was also observed feeding in this area through underwater visual census in 2021 (J Davies pers. obs. 2021). While the total number of contemporary records are low, which may be a reflection of small population size (Hiddink et al. 2019; Moore & Hiddink 2022) or that existing fishing effort has low encounter rates with angel sharks (Mason et al. 2025), this site has the only regular and predictable encounters of YOY or pregnant Angelsharks in the United Kingdom of Great Britain and Northern Ireland. Based on data collected across the region, this is one of the last known refugia for Angelsharks in the northernmost part of its range (Barker et al. 2022), thus highlighting the importance of this area for the species.

Between 2010–2024, 1,300 Thornback Skates were recorded during the BTS in this area and the broader Cardigan Bay, measuring 11–91 cm TL (Ellis et al. 2005, 2024; ICES 2025). Of these, 233 neonate/YOY Thornback Skates (14%) measuring =<30 cm TL were recorded in this area. Size-at-birth for this species is reported at ~10–13 cm TL (Last et al. 2016), with individuals up to 30 cm TL being considered neonate/YOY in other regions (Alkusairy 2019). Neonate/YOY Thornback Skates were recorded in 2010 (n = 8), 2011 (n = 8), 2012 (n = 17), 2013 (n = 9), 2014 (n = 16), 2015 (n = 20), 2016 (n = 46), 2017 (n = 25), 2018 (n = 11), 2019 (n = 16), 2021 (n = 13), 2022 (n = 16), 2023 (n = 21), and 2024 (n = 7). This area has one of the largest and most regular and predictable observations of Thornback Skates of this life stage in the United Kingdom of Great Britain and Northern Ireland.