East Anglia ONE
EMF Assessment
cables and within close proximity (a few meters) of bundled HVDC cables or HVAC cables, depending upon burial depth. However, the extent and ecological significance of such potential effects is uncertain.
6.1.2. Fish
There is extensive evidence of teleost fish possessing magnetic receptors (see Kirschvink 1997 for review), often supported by demonstrations of orientation behaviour, for example in species such as eels (Anguilla rostata; Souza et al 1988), plaice (Pleuronectes platessa; Metcalfe et al 1993), salmon (Salmo salar; Rommel & McCleave 1973; Oncorhynchus tshawaytscha; Kirschvink et al 1985) and trout (Salmo gairdneri; Chew & Brown 1989). Equally, chondrichthyans’ ability to detect magnetic fields by induction of electric fields (Kalmijn 1984), is supported by demonstrations of orientation behaviour towards magnetic fields, including species such as round stingray, Urobatis halleri, and leopard shark, Triakis semifasciata (Kalmijn 1978), and sandbar, Carcharhinus plumbeus, and scalloped hammerhead, Sphyrna lewini, sharks (Meyer et al 2004). Whether these fish would be affected by B fields from sub-sea cables, however, is unclear. Bochert & Zettler (2004) found no significant effects of static B fields upon flounder, Platichthys flesus. Swedpower (2003) found no measurable impact of subjecting salmon and trout to magnetic fields twice the magnitude of the geomagnetic field. The European eel (Anguilla anguilla) has been shown to deviate from its migration route in the presence of a 5µT HVDC field, however the effect was short term and over a short distance (Westerberg 2000; Ohman et al 2007), and such effects are therefore thought unlikely to affect key functions such as breeding or feeding success. Atlantic salmon migration in and out of the Baltic Sea, over a number of operating sub-sea HVDC cables, seems to continue unaffected (Walker 2001).
There are many relevant teleost fish taxa that inhabit the southern North Sea, including important commercial species (Parker-Humphreys 2004; Fishbase 2010). Site specific surveys for the EAONE OWF predominantly recorded benthic whiting, plaice, bib, dab, cod, raitts and greater sand eels, as well as pelagic herring, sprats, anchovies and pilchards (BBM 2011). Similar teleost assemblages were also recorded in IBTS data and during surveys at nearby OWF sites (CMACS 2005; RPS 2005; DATRAS 2011), which also mentioned Dover sole, turbot, brill and a number of goby species. Many of these species have undergone significant population declines, predominantly owing to overfishing, and some are therefore listed as Annex II species. Gobies are scheduled species under the Bern Convention, protected for their importance at the trophic level. Migrating species of teleost fish including salmon, trout and eels, and also lampreys (Agnathans or jawless fish) are also known to be present in the area, especially European eels, for which there used to be a strong fishery, and which are particularly numerous in ICES rectangle 32F1, along the proposed export cable route (DATRAS 2011). There are also a number of important elasmobranch species occurring in the area, some of which are fished, face population decline and are protected (Parker-Humphreys 2004; Compagno et al 2005). Those recorded during site specific and nearby OWF surveys and in IBTS data include small-spotted catshark, smoothhounds and spurdog (Squalus acanthias), and thornback (Raja clavata), spotted and blonde rays (CMACS 2005; RPS 2005; BBM 2001; DATRAS 2011). Others known to occur, albeit occasionally or seldomly, are nursehounds, tope (Galeorhinus galeus), thresher, porbeagle
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