[Sidenote: Attempt to plant Muscles on the Rock.]
When the workmen first landed upon the Bell Rock, limpets of a very large size were common, but were soon picked up for bait. As the limpets disappeared, we endeavoured to plant a colony of muscles, from beds at the mouth of the river Eden, of a larger kind than those which seem to be natural to the rock. These larger muscles were likely to have been useful to the workmen, and might have been especially so to the light-keepers, the future inhabitants of the rock, to whom that delicate fish would have afforded a fresh meal, as well as a better bait than the limpet; but the muscles were soon observed to open and die in great numbers. For some time this was ascribed to the effects of the violent surge of the sea, but the _Buccinum lapillus_ having greatly increased, it was ascertained that it had proved a successful enemy to the muscle. The _buccinum_ being furnished with a proboscis capable of boring, was observed to perforate a small hole in the shell, and thus to suck out the finer parts of the body of the muscle; the valves of course opened, and the remainder of the fish was washed away by the sea. The perforated hole is generally upon the thinnest part of the shell, and is perfectly circular, of a _champhered_ form, being wider towards the outward side, and so perfectly smooth and regular, as to have all the appearance of the most beautiful work of an expert artist. It became a matter extremely desirable to preserve the muscle, and it seemed practicable to extirpate the _buccinum_. But after we had picked up and destroyed many barrels of them, their extirpation was at length given up as a hopeless task. The muscles were thus abandoned as their prey: and in the course of the third year’s operations, so successful had the ravages of the _buccinum_ been, that not a single muscle of a large size was to be found upon the rock; and even the small kind which breed there, are now chiefly confined to the extreme points of the rock, where it would seem their enemy cannot so easily follow them.
In speaking of the habits of fishes, it deserves notice that they have their particular grounds and shores which they frequent; for while the vessels attending the works at the Bell Rock were stationed there, different kinds of fish were caught as the depth and bottom varied. About high-water, and especially during ebb-tide, when the sea is smooth on the rock, the _Podley_ (chiefly the fry of the coal-fish, but including also the young of the _Gadus virens_) is so numerous, as almost entirely to cover it from view. Near the rock, the small red cod is often found in abundance: at some distance, as the bottom, which is covered with marine plants near the rock, alters to coral, gravel, shell sand, fine sand and mud, all of which occur in a range of depths from 4 to 23 fathoms towards the north, different kinds of fish are found; first, the codling, which ceases to be wholly red, but becomes only speckled with reddish spots; then, upon the finer or mud grounds in the track of the tides of the Firth of Tay, whiting, haddock, flounder, and occasionally the sole. On the southern side of the rock, where the water deepens to 35 fathoms, the large white cod, in company with ling, conger-eel, halibut, skate, thornback, plaise, turbot, wolf-fish and large coal-fish are found. The dog-fish appears to be very general, and seems to prey chiefly upon the haddock and cod. The mackerel and gurnard are found together near the surface, and do not seem to be confined to particular grounds, but occur wherever the water is of a considerable depth. Herrings are found in the bays of the opposite shores in great abundance at the fishing season, when they are understood to be migrating towards the south. It has often been observed, in the course of the Bell Rock operations, that, during the cold weather of spring and autumn, and even at all seasons, in stormy weather, when the sea is much agitated by wind, the fishes disappear entirely from the vicinity of the rock, probably retreating into much deeper water, from which they do not seem to return, until a change of weather has taken place; so much was this attended to by the seamen employed on this service, that they frequently prognosticated and judged of the weather from this habit of the fishes, as well as from the appearances of the sky.