The hydrography and plankton of the Moray Firth

Abstract

SynopsisThe Moray Firth forms part of the north British coastal area of the North Sea and is distinguished by its depth, hydrography and plankton from the offshore northern North Sea. The 35·0 or 35·1 × 103 isohaline can be taken as the boundary between the two areas.Geographical and seasonal variations in temperature and salinity are described in terms of a belt of low salinity coastal water in the inner firth and along its southern shore and of “mixed” water to the north and east. During the winter the “mixed” water is warmer than the coastal water, during the summer it is colder. Tidal streams are dominantly semi-diurnal, relatively weak in the inner firth and relatively strong in the outer firth. Residual currents are largely wind driven, and some are caused by tidal effects.Geographical variation in the seasonal changes in the phytoplankton standing stock is related to water column stratification. The early spring standing stocks are highest in the inner firth and off the southern shore. During the summer and early autumn, phytoplankton is most abundant below the pycnocline. Average zooplankton standing stocks increase from 0·2–0·6 g dry weight (100m3) 1 in winter to 1.0 g (100m3) 1 exceptionally 4·5 g (100m3) 1. in summer. Standing stocks in November–December range from 0·3 to 1·8 g (100m3) 1.

Epidermal diseases in bottlenose dolphins: impacts of natural and anthropogenic factors

“…All contaminant values are given as wet weights unless asterisked. Sources: Peneda et al (1980), Adams & Martin (1986), Geraci (1989), Kirby-Smith & Costlow (1989), Morris et al (1989), Jones & Je¡s (1991), Law et al (1991), Leonzio et al (1992), Kuehl et al (1994), Levitus et al (1994), World Health Organization (1994), Corsolini et al (1995), Kuehl & Haebler (1995), Salata et al (1995), Wood & Van Vleet (1996), Kannan et al (1997), McKenzie et al (1997) each population are a¡ected. Furthermore, because only the dorsal ¢ns of the dolphins were examined, and lesions were observed on other parts of the dolphins when they could be photographed, the total levels of prevalence are likely to be higher still.…”

Inferring species interactions from co-occurrence networks with environmental DNA metabarcoding data in a coastal marine food-web

“…For example, the higher species richness of the nearshore environment could be a methodological artefact, since the water samples were collected from surface water (at 4 metres depth; Boyse et al (2023)), such that more benthic species might be detected in the shallower nearshore samples. Previous studies employing eDNA metabarcoding have detected benthic species at deeper depths (>200 m) due the presence of eddies (O’Donnell et al, 2017), although stratification in the southern Moray firth may prevent DNA mixing in the water column (Adams & Martin, 1986). Notably, our 18S primer set targeting eukaryotes failed to amplify DNA from organisms in the Malacostraca class (Crustacea), such as amphipods, carideans, decapods and isopods.…”

Evidence gathering in support of sustainable Scottish inshore fisheries: work package (4) final report: a pilot study to define the footprint and activities of Scottish inshore fisheries by identifying target fisheries, habitats and associated fish stocks

“…It has also long been known that cod eggs could be found in plankton samples collected off the Moray Firth (Wright et al 2006) and Fox et al (2008) also found some concentration of eggs in these localities, but at rather low levels compared to other parts of the North Sea. The planktonic eggs may be carried further into the Firth itself by the local water circulation (Adams & Martin 1986) although Fox et al (2008) did not survey the inner waters.…”

“…Results for cod, haddock, whiting and plaice are referred to by Hopkins (1986) who suggested that there were distinctly coastal stocks separated from the more offshore stocks of the central and northern North Sea. Along with depth, the presence of the Fair Isle current was suggested to delineate the inshore and offshore regions (Adams & Martin 1986).…”