4.2. Forth and Tay Scottish Marine Region

  1. The Forth and Tay SMR is located in the Firth of Forth 70.68 km south-west of the site boundary. Other offshore wind farm developments, either in construction or in planning stages, exist within and in the vicinity the Forth and Tay SMR, such as the Inch Cape, Neart na Gaoithe, Seagreen 1, Seagreen 1A Project and Berwick Bank Offshore Wind Farms ( Figure 3.2   Open ▸ ).
  2. Several species of commercial and ecological importance are known to be present across and in the vicinity the Forth and Tay SMR including cod, lemon sole, herring, mackerel, plaice, sandeel, saithe, sprat, spotted ray, spurdog, tope shark and whiting. The Forth and Tay SMR hosts important populations of shellfish species including Nephrops, European lobster, edible crab, velvet swimming crab and squid.
  3. An epibenthic beam trawl survey was undertaken within the Berwick Bank Offshore Wind Farm, located 56.77 km west of the site boundary and a total of 553 bony fish across 21 taxa were recorded. Common dab was the most abundant species (n=167), followed by long rough dab, lesser sandeel, pogge and gobies Pomatoschistus spp. In addition, cod, lemon sole, plaice, anglerfish and bearded rockling Enchelyopus cimbrius were also recorded at very low abundances (SSER, 2022).
  4. An epibenthic trawl survey undertaken within the boundary of the Seagreen 1 Offshore Wind Farm and 1A Project, located 50.72 km west from the site boundary, recorded pogge, common dab, Lozano’s goby P. lozanoi, Norway goby P. norvegicus, lesser sandeel, butterfish Pholis gunnellus, Norwegian topknot Phrynorhombus norvegicus, reticulated dragonet Callionymus reticulatus, common dragonet C. lyra, lemon sole and bull rout Myoxocephalus scorpius in at least 50% of the trawls. Common dab, gobies and lesser sandeel were the most abundant species. Other species observed are smooth sandeel Gymnammodytes semisquamatus and greater sandeel Hyperoplus lanceolatus, one elasmobranch species, the cuckoo ray, and commercial species such as plaice, whiting, cod, and red gurnard Chelidonichthys cuculus (Seagreen Wind Energy Ltd., 2012; 2019).
  5. Otter trawl surveys conducted in 2012 for Inch Cape Offshore Wind Farm (86.90 km from the site boundary) recorded 30 species of fish and 20 macro-invertebrates (Inch Cape Offshore Limited, 2018). Fish species included 1,194 sprat, 161 herring, and 15 cod (Inch Cape Offshore Limited, 2018). A site-specific benthic characterisation survey undertaken in 2009 for Neart na Gaoithe Offshore Wind Farm (105 km from the site boundary) recorded several fish species such as cod and flatfish (common dab, long rough dab, and plaice) (Mainstream Renewable Power, 2019).
  6. The results of site-specific surveys presented in paragraphs 39 to 41 are consistent with observations from the benthic site-specific survey of the site boundary (section 4.1.2) and support the characterisation of fish and shellfish assemblages presented herein for the fish and shellfish ecology study area.
  7. Due to the nature of the surveys undertaken, which capture only a snapshot of mobile species at the time of surveying, it is expected that further species will be present within both the site boundary and the fish and shellfish ecology study area, using the area for a variety of purposes including foraging, shelter, spawning and nursery. Information from the above desktop study has been used to support broader characterisation beyond the direct observations listed herein, and to ensure that a comprehensive and robust baseline is provided. Further information regarding the presence of mapped spawning and nursery grounds within the fish and shellfish ecology study area is presented in section 4.3.

4.3. Spawning and Nursery Grounds

  1. Spawning and/or nursery grounds for fish and shellfish species have been identified overlapping the fish and shellfish ecology study area. Coull et al. (1998) first spatially mapped the spawning/nursery areas of key fish and shellfish species in British waters based on larvae, egg and benthic habitat survey data and Ellis et al. (2012) reviewed it for a set of fin fish and elasmobranch species in the UK waters. Due to the age of the Coull et al. (1998) study, the updated areas of high and low intensity spawning and nursery grounds provided in Ellis et al. (2012) are used here unless data was not re-assessed. It is worth noting that the Ellis et al. (2012) spawning grounds are considered of lower resolution than those presented in Coull et al. (1998), due to being extrapolated as half ICES statistical rectangles rather than actual mapped densities. Additional information from Aires et al. (2014) was used to provide further understanding of nursery areas. This was evidenced by aggregations of “0 group fish” (fish in the first year of their lives) and confirmed by models of species distributions based on species observations and abundance along with environmental data (Aires et al., 2014). The outputs of this process are recommended for use as a guide for the most likely locations of aggregations of “0 group fish”.
  2. Based on the above data sources, there is a spatial overlap between the site boundary and spawning grounds for seven species of fish and shellfish and nursery grounds of 16 species. It should be noted that mapped spawning and nursery grounds do not represent a fixed area within which spawning and nursery activities occur. The boundaries and ranges for such activities are continually changing and subject to spatial and temporal variation within and outside the mapped grounds and seasons.
  3. Spawning grounds that are present within the fish and shellfish ecology study area and overlap with the site boundary include high intensity spawning grounds for sandeel, low intensity spawning grounds for cod, whiting and plaice and un-determined intensity spawning grounds for lemon sole, Norway pout and sprat ( Table 4.2   Open ▸ , Figure 4.2   Open ▸ to Figure 4.5   Open ▸ ). Mapped herring spawning grounds of unspecified intensity are also located 0.62 km from the north-west and 10.31 km from the south-west boundary of the site boundary ( Figure 4.3   Open ▸ ). The species with spawning and/or nursery grounds which overlap with the site boundary are summarised in Table 4.2   Open ▸ (spawning and nursery intensity is specified where available).
  4. Mapped low intensity nursery grounds for 11 species are also found to overlap with the site boundary, including for anglerfish, blue whiting Micromesistius poutassou, European hake Merluccius merluccius, ling, mackerel, spotted ray and spurdog, and unspecified intensity nursery grounds are present for haddock, lemon sole, sprat, and Norway pout ( Table 4.2   Open ▸ , Figure 4.2   Open ▸ to Figure 4.5   Open ▸ ). Low intensity nursery grounds for tope shark and common skate Dipturus batis are also located a minimum of 10.31 km of the north-west boundary of the site boundary ( Figure 4.6   Open ▸ ).
  5. Spawning and nursery habitats are often influenced by seabed substrate characteristics. As such, site-specific information on sediment composition can be useful to characterise spawning and nursery habitats and have been utilised to support characterisation of herring spawning and sandeel habitats in section 4.4 and section 4.5, respectively.
  6. Subtidal benthic sediments across the site boundary were found to have limited variation and ranged from muddy sand to sandy gravel, with muddy sand (32% of samples), sand (24%) and slightly gravelly sand (18%) representing the three most common sediment types reported (refer to volume 3, appendix 8.1). Sediment samples with greater than 10% mud content were only found in the south-east section of the site boundary defined as areas of muddy sand and gravelly muddy sand. The sediments within the north-west of the site boundary were dominated by sand and slightly gravelly sand, with areas of gravelly sand.

 

Table 4.2:
Key Species with Spawning and Nursery Grounds which Overlap with the Site Boundary[1]

Table 4.2: Key Species with Spawning and Nursery Grounds which Overlap with the Site Boundary[1]

 

  1. The main spawning periods of key species which have spawning grounds overlapping the site boundary are presented in Table 4.3   Open ▸ .
Table 4.3:
Main Spawning Periods for Key Fish Species with Spawning Grounds which Overlap with the Site Boundary[2]

Table 4.3: Main Spawning Periods for Key Fish Species with Spawning Grounds which Overlap with the Site Boundary[2]

Spawning periods are marked with an X, peak spawning periods marked with an O.

*Buchan stock

 

  1. Anglerfish are commonly found in deeper waters along the continental shelf and slope with adults occurring offshore and juveniles occasionally occurring in coastal waters. Despite limited data on the spawning grounds of anglerfish, they are believed to spawn in deep waters along the continental slope’s edge (Hislop et al., 2000, 2001; Arkhipov and Mylnikov, 2002; Laurenson, 2006). Therefore, anglerfish are not expected to spawn within or in the vicinity of the site boundary. However, low intensity nursery grounds for anglerfish have been identified to overlap with the site boundary (Ellis et al., 2012) ( Figure 4.2   Open ▸ ) and the occurrence of nursery grounds are further supported by outputs from Aires et al. (2014) where the presence of “0 group” anglerfish was detected in the fish and shellfish ecology study area and in the vicinity of the site boundary.
  1. While adult blue whiting and European hake have spawning grounds in the North Atlantic, juveniles have been recorded in the fish and shellfish ecology study area and mapped nursery grounds of low intensity are identified to overlap the site boundary for both species (Coull et al., 1998; Ellis et al., 2012) ( Figure 4.2   Open ▸ ). The presence of nursery grounds for European hake is further supported by Aires et al. (2014), however, these areas are not supported for blue whiting where the presence of “0 group” aggregations was not detected in the south of the northern North Sea.
  1. Cod is a common species throughout the North Sea with widespread spawning areas of low intensity occurring between January and April with a peak in February and March. Widespread nursery grounds are also present throughout the North Sea with high intensity nursery areas mapped in coastal areas, including the Firth of Forth (Coull et al., 1998; Ellis et al., 2012). Therefore, the site boundary overlaps with mapped high intensity nursery grounds and low intensity spawning grounds ( Figure 4.2   Open ▸ ) for cod. Spawning behaviour involves courtship in demersal environments typically consisting of sandy sediments and boulders (Grabowski et al., 2012), followed by the release of buoyant eggs into the water column (Hutchings et al., 1999). The presence of nursery grounds for cod is further supported by Aires et al. (2014).
  2. For haddock, no mapped spawning grounds overlap with the site boundary, however an unspecified intensity nursery ground does show overlap (Coull et al., 1998) ( Figure 4.3   Open ▸ ). Similar to cod, haddock have a demersal courting period followed by pelagic egg release and larval phases (Casaretto and Hawkins, 2012), feeding on plankton before juveniles move down towards the seabed to exploit demersal prey resources, including small crustaceans and fish. The presence of haddock nursery grounds is supported by outputs from Aires et al. (2014) and may suggest higher intensity nursery grounds within the site boundary and in its vicinity than specified by Coull et al. (1998).
  3. The site boundary lies in low intensity nursery grounds for herring with higher intensity nursery grounds mapped in coastal waters, approximately 10.31 km west of the site boundary (Ellis et al., 2012) ( Figure 4.3   Open ▸ ). The locations and intensity of herring nursery grounds are further supported by Aires et al. (2014). Herring show temporal inter-population variation in spawning activities but generally the Buchan stock (which occurs within the fish and shellfish ecology study area) spawn between August and September in inshore waters with mapped grounds located 0.62 km to north-west boundary of the site boundary ( Figure 4.3   Open ▸ ). A further review of herring spawning is presented in section 4.4.
  4. Ling have been found to spawn in the Irish Sea and Bristol Channel between March and July with their main nursery areas further offshore in the North Atlantic but not in the North Sea (Ellis et al., 2012). However, mapped low intensity nursery grounds overlap with the site boundary (Ellis et al., 2012) ( Figure 4.3   Open ▸ ). Primary nursery grounds are difficult to establish due to a lack of data and poor success with trawl surveys, therefore mapped nursery grounds relate to the presence of secondary nursery grounds, based on individuals of less than 49 cm in length which are widely considered immature (Ellis et al., 2012). The largest catches of immature ling are generally from deeper waters.
  5. Spawning of lemon sole occurs between April and September, with no defined peak period (Smith, 2014), although evidence exists of spawning in October to November dependent on stock and location (Geffen et al., 2021), with lemon sole utilising their preferred benthic habitats for spawning (Hinz et al., 2006). There are mapped nursery and spawning grounds of unspecified intensity for lemon sole which coincide with much of the site boundary ( Figure 4.3   Open ▸ ).
  1. Mackerel have low intensity nursery grounds which overlap with the site boundary (Ellis et al., 2012), with no spawning grounds identified within or in proximity to the site boundary ( Figure 4.4   Open ▸ ). Mackerel spawning behaviour involves the release of eggs into the water column, where fertilisation also occurs (Walsh and Johnstone, 2006), indicating a low level of reliance on sedimentary habitats for spawning. The presence of mackerel nursery grounds is not supported by outputs from Aires et al. (2014), with no modelled observations of “0 group fish” on the east coast of Scotland.
  2. Mapped plaice spawning and nursery grounds of low intensity coincide with the site boundary (Ellis et al., 2012). Spawning activities take place over the winter with peak spawning in January and February and each female producing up to half a million eggs which drift passively in the plankton (Ruiz, 2007). Once the larvae reach a suitable size for settlement, they metamorphose into their asymmetric body shape. As juveniles, they inhabit mostly shallow water, including tidal pools (Schreiber, 2013). In their second year they move into deeper water and are mostly found in a depth range of 10 m to 50 m. Plaice use coastal and estuarine habitats as nurseries, and these low intensity nursery grounds overlap with the site boundary (Ellis et al., 2012) ( Figure 4.4   Open ▸ ). The presence of low intensity nursery grounds in inshore waters is further supported by Aires et al. (2014).
  3. Sandeel spawn during winter months across the majority of the North Sea with nursery grounds spanning over a similar area due to the demersal egg stage and sediment preferences for habitation throughout their life cycle (Ellis et al., 2012). The site boundary coincides with low intensity spawning and nursery grounds ( Figure 4.4   Open ▸ ), however mapped high intensity spawning grounds are located 10.31 km north-west of the site boundary at the closest point. A further review of the potential distribution of sandeel grounds is presented in section 4.5.
  4. Sprat nursery and spawning grounds of unspecified intensity partially overlap with the site boundary (Ellis et al., 2012), with the nursery areas coinciding with the north-west section of the site boundary and spawning grounds (occurring mostly from May to June but extending until August) encompassing the majority of the site boundary ( Figure 4.4   Open ▸ ). The presence of sprat nursery grounds is only slightly supported by outputs from Aires et al. (2014), with aggregations of “0 group fish” seemingly limited to areas further inshore, outside of the site boundary.
  5. The site boundary is located in mapped whiting spawning grounds of low intensity and nursery grounds of high intensity ( Figure 4.6   Open ▸ ). Low intensity nursery areas overlap with the eastern tip of the site boundary (Coull et al., 1998; Ellis et al., 2012) ( Figure 4.6   Open ▸ ). Whiting spawn across multiple months from February to June with no peak in the spawning activities. Spawning is not thought to be substrate dependent as eggs are released into the water column. For example, a recent study demonstrated that this species showed high plasticity in spawning ground selection with extensive areas of the North Sea appearing suitable (González-Irusta and Wright, 2017). After the eggs hatch, the larvae drift in surface waters for a year, and then move closer to the seabed as juveniles. The presence of whiting nursery grounds is supported by outputs from Aires et al. (2014).
  6. Norway pout spawn from January to May with a peak in February and March in the northern North Sea and off the west coast of Scotland, with the mapped nursery grounds spanning a similar area. Based on Coull et al. (1998) only, the site boundary overlaps with mapped low intensity spawning grounds and unspecified intensity nursery grounds ( Figure 4.5   Open ▸ ).
  7. Two species of elasmobranch, the spotted ray and spurdog, have mapped low intensity nursery grounds which overlap the site boundary (Ellis et al., 2012) ( Figure 4.5   Open ▸ ). Although spawning activities are expected to broadly occur in similar areas as nursery grounds, spawning grounds have not been defined due to insufficient data (Ellis et al., 2012).
  8. Mapped nursery grounds of low intensity for the common skate and tope shark, are located 10.31 km to the west of the site boundary (Ellis et al., 2012) ( Figure 4.6   Open ▸ ). Spawning grounds have not been defined due to insufficient data (Ellis et al., 2012), but tope shark, as a viviparous species, are thought to spawn throughout the year with gravid females captured year-round.
  9. The spawning or nursery grounds of saithe do not coincide with the site boundary, although nursery grounds of unspecified intensity are located within the fish and shellfish ecology study area off the coast of Aberdeen, 48.13 km west from the site boundary ( Figure 4.6   Open ▸ ) (Coull et al., 1998).
  10. Coincidental spawning and nursery grounds of unspecified intensity for Nephrops are located within the fish and shellfish ecology study area but do not overlap the site boundary ( Figure 4.6   Open ▸ ). Mapped grounds are located a minimum of 45.94 km to the north-west, west and south of the site boundary and extend along much of the coast of the Firth of Forth (Coull et al., 1998). Shellfish species are further discussed in section 4.8.


Figure 4.2:
Spawning and Nursery Areas Overlapping with the Site Boundary: Anglerfish, Blue Whiting, Cod and European Hake (Source: Coull et al., 1998 and Ellis et al., 2012)

Figure 4.2: Spawning and Nursery Areas Overlapping with the Site Boundary: Anglerfish, Blue Whiting, Cod and European Hake (Source: Coull et al., 1998 and Ellis et al., 2012)


Figure 4.3:
Spawning and Nursery Areas Overlapping with the Site Boundary: Haddock, Herring, Ling and Lemon Sole (Source: Coull et al., 1998 and Ellis et al., 2012)

Figure 4.3: Spawning and Nursery Areas Overlapping with the Site Boundary: Haddock, Herring, Ling and Lemon Sole (Source: Coull et al., 1998 and Ellis et al., 2012)


Figure 4.4:
Spawning and Nursery Areas Overlapping with the Site Boundary: Mackerel, Plaice, Sandeel and Sprat (Source: Coull et al., 1998 and Ellis et al., 2012)

Figure 4.4: Spawning and Nursery Areas Overlapping with the Site Boundary: Mackerel, Plaice, Sandeel and Sprat (Source: Coull et al., 1998 and Ellis et al., 2012)


Figure 4.5:
Spawning and Nursery Areas Overlapping with the Site Boundary: Whiting, Norway Pout, Spotted Ray and Spurdog (Source: Coull et al., 1998 and Ellis et al., 2012)

Figure 4.5: Spawning and Nursery Areas Overlapping with the Site Boundary: Whiting, Norway Pout, Spotted Ray and Spurdog (Source: Coull et al., 1998 and Ellis et al., 2012)


Figure 4.6:
Spawning and Nursery Areas in Proximity to the Site Boundary: Common Skate, Tope Shark, Nephrops and Saithe (Source: Coull et al., 1998 and Ellis et al., 2012)

Figure 4.6: Spawning and Nursery Areas in Proximity to the Site Boundary: Common Skate, Tope Shark, Nephrops and Saithe (Source: Coull et al., 1998 and Ellis et al., 2012)